Journal articles on the topic 'Anaerobic bacteria Adaptation'
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Hamad, Mohamad A., Chad R. Austin, Amanda L. Stewart, Mike Higgins, Andrés Vázquez-Torres, and Martin I. Voskuil. "Adaptation and Antibiotic Tolerance of Anaerobic Burkholderia pseudomallei." Antimicrobial Agents and Chemotherapy 55, no. 7 (May 2, 2011): 3313–23. http://dx.doi.org/10.1128/aac.00953-10.
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ABSTRACTThe Gram-negative bacteriumBurkholderia pseudomalleiis the etiological agent of melioidosis and is remarkably resistant to most classes of antibacterials. Even after months of treatment with antibacterials that are relatively effectivein vitro, there is a high rate of treatment failure, indicating that this pathogen alters its patterns of antibacterial susceptibility in response to cues encountered in the host. The pathology of melioidosis indicates thatB. pseudomalleiencounters host microenvironments that limit aerobic respiration, including the lack of oxygen found in abscesses and in the presence of nitric oxide produced by macrophages. We investigated whetherB. pseudomalleicould survive in a nonreplicating, oxygen-deprived state and determined if this physiological state was tolerant of conventional antibacterials.B. pseudomalleisurvived initial anaerobiosis, especially under moderately acidic conditions similar to those found in abscesses. Microarray expression profiling indicated a major shift in the physiological state of hypoxicB. pseudomallei, including induction of a variety of typical anaerobic-environment-responsive genes and genes that appear specific to anaerobicB. pseudomallei. Interestingly, anaerobicB. pseudomalleiwas unaffected by antibacterials typically used in therapy. However, it was exquisitely sensitive to drugs used against anaerobic pathogens. After several weeks of anaerobic culture, a significant loss of viability was observed. However, a stable subpopulation that maintained complete viability for at least 1 year was established. Thus, during the course of human infection, if a minor subpopulation of bacteria inhabited an oxygen-restricted environment, it might be indifferent to traditional therapy but susceptible to antibiotics frequently used to treat anaerobic infections.
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Karasova, Daniela, Marcela Faldynova, Jitka Matiasovicova, Alena Sebkova, Magdalena Crhanova, Tereza Kubasova, Zuzana Seidlerova, et al. "Host Species Adaptation of Obligate Gut Anaerobes Is Dependent on Their Environmental Survival." Microorganisms 10, no. 6 (May 25, 2022): 1085. http://dx.doi.org/10.3390/microorganisms10061085.
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The gut microbiota of warm-blooded vertebrates consists of bacterial species belonging to two main phyla; Firmicutes and Bacteroidetes. However, does it mean that the same bacterial species are found in humans and chickens? Here we show that the ability to survive in an aerobic environment is central for host species adaptation. Known bacterial species commonly found in humans, pigs, chickens and Antarctic gentoo penguins are those capable of extended survival under aerobic conditions, i.e., either spore-forming, aerotolerant or facultatively anaerobic bacteria. Such bacteria are ubiquitously distributed in the environment, which acts as the source of infection with similar probability in humans, pigs, chickens, penguins and likely any other warm-blooded omnivorous hosts. On the other hand, gut anaerobes with no specific adaptation for survival in an aerobic environment exhibit host adaptation. This is associated with their vertical transmission from mothers to offspring and long-term colonisation after administration of a single dose. This knowledge influences the design of next-generation probiotics. The origin of aerotolerant or spore-forming probiotic strains may not be that important. On the other hand, if Bacteroidetes and other host-adapted species are used as future probiotics, host preference should be considered.
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Finn, Thomas J., Sonal Shewaramani, Sinead C. Leahy, Peter H. Janssen, and Christina D. Moon. "Dynamics and genetic diversification ofEscherichia coliduring experimental adaptation to an anaerobic environment." PeerJ 5 (May 3, 2017): e3244. http://dx.doi.org/10.7717/peerj.3244.
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BackgroundMany bacteria are facultative anaerobes, and can proliferate in both anoxic and oxic environments. Under anaerobic conditions, fermentation is the primary means of energy generation in contrast to respiration. Furthermore, the rates and spectra of spontaneous mutations that arise during anaerobic growth differ to those under aerobic growth. A long-term selection experiment was undertaken to investigate the genetic changes that underpin how the facultative anaerobe,Escherichia coli, adapts to anaerobic environments.MethodsTwenty-one populations ofE. coliREL4536, an aerobically evolved 10,000th generation descendent of theE. coliB strain, REL606, were established from a clonal ancestral culture. These were serially sub-cultured for 2,000 generations in a defined minimal glucose medium in strict aerobic and strict anaerobic environments, as well as in a treatment that fluctuated between the two environments. The competitive fitness of the evolving lineages was assessed at approximately 0, 1,000 and 2,000 generations, in both the environment of selection and the alternative environment. Whole genome re-sequencing was performed on random colonies from all lineages after 2,000-generations. Mutations were identified relative to the ancestral genome, and based on the extent of parallelism, traits that were likely to have contributed towards adaptation were inferred.ResultsThere were increases in fitness relative to the ancestor among anaerobically evolved lineages when tested in the anaerobic environment, but no increases were found in the aerobic environment. For lineages that had evolved under the fluctuating regime, relative fitness increased significantly in the anaerobic environment, but did not increase in the aerobic environment. The aerobically-evolved lineages did not increase in fitness when tested in either the aerobic or anaerobic environments. The strictly anaerobic lineages adapted more rapidly to the anaerobic environment than did the fluctuating lineages. Two main strategies appeared to predominate during adaptation to the anaerobic environment: modification of energy generation pathways, and inactivation of non-essential functions. Fermentation pathways appeared to alter through selection for mutations in genes such asnadR, adhE, dcuS/R, andpflB. Mutations were frequently identified in genes for presumably dispensable functions such as toxin-antitoxin systems, prophages, virulence and amino acid transport. Adaptation of the fluctuating lineages to the anaerobic environments involved mutations affecting traits similar to those observed in the anaerobically evolved lineages.DiscussionThere appeared to be strong selective pressure for activities that conferred cell yield advantages during anaerobic growth, which include restoring activities that had previously been inactivated under long-term continuous aerobic evolution of the ancestor.
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Hemsley, Claudia M., Jamie X. Luo, Clio A. Andreae, Clive S. Butler, Orkun S. Soyer, and Richard W. Titball. "Bacterial Drug Tolerance under Clinical Conditions Is Governed by Anaerobic Adaptation but not Anaerobic Respiration." Antimicrobial Agents and Chemotherapy 58, no. 10 (July 21, 2014): 5775–83. http://dx.doi.org/10.1128/aac.02793-14.
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ABSTRACTNoninherited antibiotic resistance is a phenomenon whereby a subpopulation of genetically identical bacteria displays phenotypic tolerance to antibiotics. We show here that compared toEscherichia coli, the clinically relevant genusBurkholderiadisplays much higher levels of cells that tolerate ceftazidime. By measuring the dynamics of the formation of drug-tolerant cells under conditions that mimicin vivoinfections, we show that inBurkholderiabacteria, oxygen levels affect the formation of these cells. The drug-tolerant cells are characterized by an anaerobic metabolic signature and can be eliminated by oxygenating the system or adding nitrate. The transcriptome profile suggests that these cells are not dormant persister cells and are likely to be drug tolerant as a consequence of the upregulation of anaerobic nitrate respiration, efflux pumps, β-lactamases, and stress response proteins. These findings have important implications for the treatment of chronic bacterial infections and the methodologies and conditions that are used to study drug-tolerant and persister cellsin vitro.
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Peng, Meng-Wen, Yong Guan, Jian-Hong Liu, Liang Chen, Han Wang, Zheng-Zhe Xie, Hai-Yan Li, et al. "Quantitative three-dimensional nondestructive imaging of whole anaerobic ammonium-oxidizing bacteria." Journal of Synchrotron Radiation 27, no. 3 (April 17, 2020): 753–61. http://dx.doi.org/10.1107/s1600577520002349.
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Anaerobic ammonium-oxidizing (anammox) bacteria play a key role in the global nitrogen cycle and in nitrogenous wastewater treatment. The anammox bacteria ultrastructure is unique and distinctly different from that of other prokaryotic cells. The morphological structure of an organism is related to its function; however, research on the ultrastructure of intact anammox bacteria is lacking. In this study, in situ three-dimensional nondestructive ultrastructure imaging of a whole anammox cell was performed using synchrotron soft X-ray tomography (SXT) and the total variation-based simultaneous algebraic reconstruction technique (TV-SART). Statistical and quantitative analyses of the intact anammox bacteria were performed. High soft X-ray absorption composition inside anammoxosome was detected and verified to be relevant to iron-binding protein. On this basis, the shape adaptation of the anammox bacteria response to iron was explored.
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Gehrke, Peter, Philip Hartjen, Ralf Smeets, Martin Gosau, Ulrike Peters, Thomas Beikler, Carsten Fischer, et al. "Marginal Adaptation and Microbial Leakage at Conometric Prosthetic Connections for Implant-Supported Single Crowns: An In Vitro Investigation." International Journal of Molecular Sciences 22, no. 2 (January 17, 2021): 881. http://dx.doi.org/10.3390/ijms22020881.
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Encouraging clinical results were reported on a novel cone-in-cone coupling for the fixation of dental implant-supported crowns (Acuris, Dentsply Sirona Implants, Mölndal, Sweden). However, the presence or absence of a microgap and a potential bacterial leakage at the conometric joint has not yet been investigated. A misfit and a resulting gap between the conometric components could potentially serve as a bacterial reservoir that promotes plaque formation, which in turn may lead to inflammation of the peri-implant tissues. Thus, a two-fold study set-up was designed in order to evaluate the bidirectional translocation of bacteria along conometrically seated single crowns. On conometric abutments filled with a culture suspension of anaerobic bacteria, the corresponding titanium nitride-coated (TiN) caps were fixed by friction. Each system was sterilized and immersed in culture medium to provide an optimal environment for microbial growth. Positive and negative controls were prepared. Specimens were stored in an anaerobic workstation, and total and viable bacterial counts were determined. Every 48 h, samples were taken from the reaction tubes to inoculate blood agar plates and to isolate bacterial DNA for quantification using qrt-PCR. In addition, one Acuris test system was subjected to scanning electron microscopy (SEM) to evaluate the precision of fit of the conometric coupling and marginal crown opening. Throughout the observational period of one week, blood agar plates of the specimens showed no viable bacterial growth. qrt-PCR, likewise, yielded a result approaching zero with an amount of about 0.53 × 10−4 µg/mL DNA. While the luting gap/marginal opening between the TiN-cap and the ceramic crown was within the clinically acceptable range, the SEM analysis failed to identify a measurable microgap at the cone-in-cone junction. Within the limits of the in-vitro study it can be concluded that the Acuris conometric interface does not allow for bacterial translocation under non-dynamic loading conditions.
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Boyd, Eric S., Amaya M. Garcia Costas, Trinity L. Hamilton, Florence Mus, and John W. Peters. "Evolution of Molybdenum Nitrogenase during the Transition from Anaerobic to Aerobic Metabolism." Journal of Bacteriology 197, no. 9 (March 2, 2015): 1690–99. http://dx.doi.org/10.1128/jb.02611-14.
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ABSTRACTMolybdenum nitrogenase (Nif), which catalyzes the reduction of dinitrogen to ammonium, has modulated the availability of fixed nitrogen in the biosphere since early in Earth's history. Phylogenetic evidence indicates that oxygen (O2)-sensitive Nif emerged in an anaerobic archaeon and later diversified into an aerobic bacterium. Aerobic bacteria that fix N2have adapted a number of strategies to protect Nif from inactivation by O2, including spatial and temporal segregation of Nif from O2and respiratory consumption of O2. Here we report the complement of Nif-encoding genes in 189 diazotrophic genomes. We show that the evolution of Nif during the transition from anaerobic to aerobic metabolism was accompanied by both gene recruitment and loss, resulting in a substantial increase in the number ofnifgenes. While the observed increase in the number ofnifgenes and their phylogenetic distribution are strongly correlated with adaptation to utilize O2in metabolism, the increase is not correlated with any of the known O2protection mechanisms. Rather, gene recruitment appears to have been in response to selective pressure to optimize Nif synthesis to meet fixed N demands associated with aerobic productivity and to more efficiently regulate Nif under oxic conditions that favor protein turnover. Consistent with this hypothesis, the transition of Nif from anoxic to oxic environments is associated with a shift from posttranslational regulation in anaerobes to transcriptional regulation in obligate aerobes and facultative anaerobes. Given that fixed nitrogen typically limits ecosystem productivity, our observations further underscore the dynamic interplay between the evolution of Earth's oxygen, nitrogen, and carbon biogeochemical cycles.IMPORTANCEMolybdenum nitrogenase (Nif), which catalyzes the reduction of dinitrogen to ammonium, has modulated the availability of fixed nitrogen in the biosphere since early in Earth's history. Nif emerged in an anaerobe and later diversified into aerobes. Here we show that the transition of Nif from anaerobic to aerobic metabolism was accompanied by both gene recruitment and gene loss, resulting in a substantial increase in the number ofnifgenes. While the observed increase in the number ofnifgenes is strongly correlated with adaptation to utilize O2in metabolism, the increase is not correlated with any of the known O2protective mechanisms. Rather, gene recruitment was likely a response to more efficiently regulate Nif under oxic conditions that favor protein turnover.
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Sierra-Alvarez, R., J. A. Field, S. Kortekaas, and G. Lettinga. "Overview of the Anaerobic Toxicity Caused by Organic Forest Industry Wastewater Pollutants." Water Science and Technology 29, no. 5-6 (March 1, 1994): 353–63. http://dx.doi.org/10.2166/wst.1994.0728.
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Numerous types of organic environmental pollutants are encountered in forest industry effluents which potentially could inhibit consortia of anaerobic bacteria. The purpose of this study was to collect anaerobic bioassay data from the literature to better estimate the impact of these pollutants on anaerobic wastewater treatment systems. The most important methanogenic inhibitors in forest industry wastewaters are wood resin, chlorophenols and tannins. These compounds account for toxicity in alkaline pulping liquors, bleaching effluents and debarking wastewaters, respectively. Adaptation to chlorophenol toxicity can be expected since they are eventually degraded in anaerobic systems. Wood resin compounds, on the other hand, are not biodegraded anaerobically and therefore their toxicity is persistent. Toxicity in forest industry wastewaters does not necessarily preclude anaerobic treatment. A variety of techniques can be employed to diminish inhibition, such as dilution and detoxification treatments.
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Jensen, Dan B., and David W. Ussery. "Bayesian prediction of microbial oxygen requirement." F1000Research 2 (September 13, 2013): 184. http://dx.doi.org/10.12688/f1000research.2-184.v1.
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Background: Prediction of the optimal habitat conditions for a given bacterium, based on genome sequence alone would be of value for scientific as well as industrial purposes. One example of such a habitat adaptation is the requirement for oxygen. In spite of good genome data availability, there have been only a few prediction attempts of bacterial oxygen requirements, using genome sequences. Here, we describe a method for distinguishing aerobic, anaerobic and facultative anaerobic bacteria, based on genome sequence-derived input, using naive Bayesian inference. In contrast, other studies found in literature only demonstrate the ability to distinguish two classes at a time. Results: The results shown in the present study are as good as or better than comparable methods previously described in the scientific literature, with an arguably simpler method, when results are directly compared. This method further compares the performance of a single-step naive Bayesian prediction of the three included classifications, compared to a simple Bayesian network with two steps. A two-step network, distinguishing first respiring from non-respiring organisms, followed by the distinction of aerobe and facultative anaerobe organisms within the respiring group, is found to perform best. Conclusions: A simple naive Bayesian network based on the presence or absence of specific protein domains within a genome is an effective and easy way to predict bacterial habitat preferences, such as oxygen requirement.
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Taotao, Zeng, Li Dong, Zeng Huiping, Xie Shuibo, Qiu Wenxin, Liu Yingjiu, and Zhang Jie. "Nitrogen removal efficiency and microbial community analysis of ANAMMOX biofilter at ambient temperature." Water Science and Technology 71, no. 5 (January 19, 2015): 725–33. http://dx.doi.org/10.2166/wst.2015.019.
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An upflow anaerobic biofilter (AF) was developed to investigate anaerobic ammonium-oxidizing (ANAMMOX) efficiency in treating low-strength wastewater at ambient temperature (15.3–23.2 °C). Denaturing gradient gel electrophoresis (DGGE) and fluorescence in situ hybridization were used to investigate treatment effects on the microbial community. Stepwise decreases in influent ammonia concentration could help ANAMMOX bacteria selectively acclimate to low-ammonia conditions. With an influent ammonia concentration of 46.5 mg/L, the AF reactor obtained an average nitrogen removal rate of 2.26 kg/(m3 day), and a removal efficiency of 75.9%. polymerase chain reaction-DGGE results showed that microbial diversity in the low matrix was greater than in the high matrix. Microbial community structures changed when the influent ammonia concentration decreased. The genus of functional ANAMMOX bacteria was Candidatus Kuenenia stuttgartiensis, which remained stationary across study phases. Visual observation revealed that the relative proportions of ANAMMOX bacteria decreased from 41.6 to 36.3% across three study phases. The AF bioreactor successfully maintained high activity due to the ANAMMOX bacteria adaptation to low temperature and substrate conditions.
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Ouwerkerk, Janneke P., Kees C. H. van der Ark, Mark Davids, Nico J. Claassens, Teresa Robert Finestra, Willem M. de Vos, and Clara Belzer. "Adaptation of Akkermansia muciniphila to the Oxic-Anoxic Interface of the Mucus Layer." Applied and Environmental Microbiology 82, no. 23 (September 23, 2016): 6983–93. http://dx.doi.org/10.1128/aem.01641-16.
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ABSTRACTAkkermansia muciniphilacolonizes the mucus layer of the gastrointestinal tract, where the organism can be exposed to the oxygen that diffuses from epithelial cells. To understand howA. muciniphilais able to survive and grow at this oxic-anoxic interface, its oxygen tolerance and response and reduction capacities were studied.A. muciniphilawas found to be oxygen tolerant. On top of this, under aerated conditions,A. muciniphilashowed significant oxygen reduction capacities and its growth rate and yield were increased compared to those seen under strict anaerobic conditions. Transcriptome analysis revealed an initial oxygen stress response upon exposure to oxygen. Thereafter, genes related to respiration were expressed, including those coding for the cytochromebdcomplex, which can function as a terminal oxidase. The functionality ofA. muciniphilacytochromebdgenes was proven by successfully complementing cytochrome-deficientEscherichia colistrain ECOM4. We conclude thatA. muciniphilacan use oxygen when it is present at nanomolar concentrations.IMPORTANCEThis article explains howAkkermansia muciniphila, previously described as a strictly anaerobic bacterium, is able to tolerate and even benefit from low levels of oxygen. Interestingly, we measured growth enhancement ofA. muciniphilaand changes in metabolism as a result of the oxygen exposure. In this article, we discuss similarities and differences of this oxygen-responsive mechanism with respect to those of other intestinal anaerobic isolates. Taken together, we think that these are valuable data that indicate how anaerobic intestinal colonizing bacteria can exploit low levels of oxygen present in the mucus layer and that our results have direct relevance for applicability, as addition of low oxygen concentrations could benefit thein vitrogrowth of certain anaerobic organisms.
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Hnatush, S. O., O. M. Moroz, G. V. Yavorska, and B. M. Borsukevych. "Sulfidogenic and metal reducing activities of Desulfuromonas genus bacteria under the influence of copper chloride." Biosystems Diversity 26, no. 3 (August 20, 2018): 218–26. http://dx.doi.org/10.15421/011833.
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The selection of strains isolated from technogenically altered ecotopes and resistant to contamination, capable of metabolizing a wide range of pollutants is a task highly relevant for creation of new methods for environmental purification. Sulphur-reducing bacteria of the Desulfuromonas genus carry out dissimilatory reduction not only of S0 but also oxidized forms of metals. Intensity of anaerobic respiration of microorganisms in polluted environments is determined by level of their adaptation to stress factors, in particular, copper (II) compounds. The aim of this work was to investigate the influence of copper (II) chloride on H2S production by Desulfuromonas sp. strains isolated by us from Yavorivske Lake, to determine the efficiency of Cu2+ precipitation by hydrogen sulfide, to analyse the possibility of usage by bacteria of CuCl2 as an electron acceptor of anaerobic respiration and to study the influence of Cu2+ on usage by these microorganisms of ferric (III) citrate, potassium dichromate or manganese (IV) oxide as electron acceptors. Bacteria were grown under anaerobic conditions in Kravtsov-Sorokin medium. To study the influence of Cu2+ on production by bacteria of H2S, their cells were incubated with CuCl2 (0.5–4.0 mM), washed and cultivated in a medium with S0. To determine the level of Cu2+ binding by H2S, produced by bacteria, cells were grown in a medium with CuCl2 (0.5–4.0 mM) and S0. To investigate the ability of bacteria to use copper (II) ions as electron acceptors, they were cultivated in a medium with CuCl2 (1.74–10.41 mM). To study the influence of Cu2+ on usage by bacteria of metal compounds as electron acceptors, their cells were incubated with CuCl2 (0.5–4.0 mM), washed and cultivated in media with C6H5O7Fe, K2Cr2O7 or MnO2 (1.74–10.41 mM). Biomass was determined by the turbidimetric method. In the cultural liquid the content of H2S was determined quantitatively by the spectrophotometric method, qualitatively – presence of Cu2+. Content of CuS in the growth medium was determined by weight method. Desulfuromonas sp. bacteria was revealed to be resistant to 2.0–2.5 mM copper (II) ions. Under the influence of 3.0–4.0 mM CuCl2 in the incubation mixture, sulfidogenic activity of bacteria decreased more than twice. The efficiency of Cu2+ binding in form of CuS by H2S produced by bacteria reached 97.3–100.0% at presence in the medium with S0 of up to 1.5 mM CuCl2. Bacteria used CuCl2 (1.74–10.41 mM) as an electron acceptor in the process of anaerobic respiration. The addition of 2.5–3.0 mM CuCl2 to the incubation mixture caused inhibition of metal reducing activity of cells, growth of all strains in media with 1.74–10.41 mM ferric (III) citrate, potassium dichromate or manganese (IV) oxide as electron acceptors decreased by 2.6 times. Almost complete precipitation up to 1.5 mM copper (II) ions in form of CuS by H2S produced by bacteria and ability to reduce up to 10.41 mM CuCl2, C6H5O7Fe, K2Cr2O7 or MnO2 in the process of anaerobic respiration indicates a high adaptation of the bacteria strains investigated by us to stress factors, in particular, the influence of CuCl2. We have proved the possibility of using Desulfuromonas sp. in biotechnologies for purification of environments with complex contamination from copper (II) compounds.
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Yanqoritha, Nyimas, Muhammad Turmuzi, Irvan Irvan, Fatimah Batubara, and Ilmi Ilmi. "Acclimatization Process on Hybrid Upflow Anaerobic Sludge Blanket Reactor (HUASBR) using Bioball as Growth Media with OLR Variation for Treating Tofu Wastewater." Oriental Journal of Chemistry 34, no. 6 (November 13, 2018): 3100–3105. http://dx.doi.org/10.13005/ojc/340654.
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Wastewater of tofu industry contains very high organic content, then anaerobic process is the most suitable for degrading this liquid waste. The hybrid upflow anaerobic sludge blanket reactor (HUASBR) was applied in this study because it has the advantage in ensuring good contact between biomass and substrate where a suspension medium and anaerobic filter are able to withstand more biomass in the attached media. Processing Anaerobic process is carried out with the help of bacteria where bacteria need seeding and acclimatization. Acclimatization is the process of adaptation of microorganisms to wastewater to be treated. This adaptation process is carried out by adding waste water from the smallest concentration to the actual concentration. The purpose of this study is to determine the effect of variations in organic load rate (OLR) on the acclimatization process in removing COD, biogas production in accordance with the pH of the anaerobic degradation process so that the optimal process of the acclimatization process can be obtained. In this study, the acclimatization process took 200 days with variation of OLR in the range of 1.5 - 5.9 kg COD m-3 d-1 at HRT 24 hours and flow rate up (Vup) of 0.08 m/h. The objective of OLR variation was to evaluate acclimatization process on the HUASBR performance during process optimization. The highest biogas production and removal efficiency of COD were achieved in pH range of 6.5 - 7.6. While, the highest COD removal efficiency obtained was 86.57% on the 140th day and biogas production 7700 ml for OLR 4.8 kg COD m-3d-1 at HRT 24 h. Consequently, the optimum OLR for treating the tofu wastewater could be achieved up to 4.8 kg COD m-3d-1 and HRT 24h.
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KONTCHOU, C. YANZE, and R. BLONDEAU. "EFFECT OF HETEROTROPHIC BACTERIA ON DIFFERENT HUMIC SUBSTANCES IN MIXED BATCH CULTURES." Canadian Journal of Soil Science 70, no. 1 (February 1, 1990): 51–59. http://dx.doi.org/10.4141/cjss90-006.
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Humic substances extracted from different soil samples and synthetic humic compounds (two melanoidins and one synthetic polymer) were used as the sole carbon source in liquid media inoculated with a mixed bacterial community selected by adaptation culture technique, and incubated for 90 or 100 d. The results show a high resistance to degradation of humic compounds by heterotrophic bacteria. Only a slight decrease in carbohydrate content and some modifications in carboxyl content were observed with the natural compounds. This resistance to biodegradation does not seem to be related to sample origin (e.g., forest humic substances compared to cultivated soil humic substances), or extraction procedure (sodium pyrophosphate compared to sodium hydroxide). Fulvic acids were as refractory as humic acids. The action of heterotrophic bacteria on incubated humic substances was similar under anaerobic (with nitrate reducing conditions) and aerobic conditions. Key words: Fulvic acids, humic acids, humus recalcitrance, melanoidins
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Nguyen, Huu Thanh, Thanh Dung Nguyen, Phu Tho Nguyen, Thi To Uyen Nguyen, Nhi Binh Bui, Thuy Vy Pham, Hoang Tinh Nguyen, Chi Thien Dang, and Thi Bich Nhu Nguyen. "Improving the viability of Lactobacillus plantarum VAL6using environmental-stress adaptation." Ministry of Science and Technology, Vietnam 64, no. 11 (November 25, 2022): 59–64. http://dx.doi.org/10.31276/vjst.64(11).59-64.
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To demonstrate the adaptation of lactic acid bacteria to environmental stresses can improve cell viability during freeze-drying, the Lactobacillus plantarum VAL6 strain was cultured under different stress conditions, including temperature, pH, and increase in CO2 concentration. The results of densitometry analysis showed that the strain was able to survive in harsh environmental conditions such as at pH 2.5, the temperature at 47oC, and in anaerobic conditions created by CO2. In particular, the CO2 intensification culture could stimulate an increase in the density of L. plantarum VAL6, reaching 9.4 compared to 9 LogCFU/ml under normal culture conditions. After cells were adapted to environmental stress at pH 3.5, the highest survival rate after freeze-drying of L. plantarum VAL6 was 28% (2,500 times higher than that of the control). The results showed the potential to use environmental stresses to increase the survival rate of starter lactic acid bacteria strains for food applications.
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Kawasaki, Shinji, Ippei Suzuki, and Youichi Niimura. "Oxygen adaptation mechanism of anaerobic bacteria Microbial ecology under 0 ～ 21% oxygen concentrations ." Japanese Journal of Lactic Acid Bacteria 24, no. 2 (2013): 79–87. http://dx.doi.org/10.4109/jslab.24.79.
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Hossain, Md Iqbal, Andrea Paparini, and Ralf Cord-Ruwisch. "Rapid adaptation of activated sludge bacteria into a glycogen accumulating biofilm enabling anaerobic BOD uptake." Bioresource Technology 228 (March 2017): 1–8. http://dx.doi.org/10.1016/j.biortech.2016.11.102.
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Castro, Laura, M. Blázquez, Felisa González, Jesús Muñoz, and Antonio Ballester. "Anaerobic Bioreduction of Jarosites and Biofilm Formation by a Natural Microbial Consortium." Minerals 9, no. 2 (January 29, 2019): 81. http://dx.doi.org/10.3390/min9020081.
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Jarosite occurs naturally in acid sulphate soils and is a common feature of streams impacted by acid mine drainage (AMD). Biological reduction of iron-sulphate minerals, such as jarosite, has the potential to contribute to the natural attenuation of acid mine drainage sites. The reduction of different jarosites (including minerals containing precious and toxic metals) by a natural bacterial/microbial consortium was examined in this study. Jarosites was used as a sole terminal electron acceptor via the reductive dissolution of Fe(III) minerals. The production of Fe(II) and the presence of sulphate-reducing bacteria in the consortium lead to the precipitation of metal sulphides immobilizing toxic heavy metals. Microbial attachment and biofilm formation of minerals have a great impact on the production and transformation of minerals and can influence the mobility of metals. After the adaptation to different jarosites, a unique specie was found: Desulfosporosinus orientis. Desulfosporosinus species are sulphate-reducing bacteria and can be found in sulphate-rich heavy metal-polluted environments, such as acid mine/rock drainage sites, being responsible for the sulphides formation. D. orientis is an obligate anaerobic microorganism and is able to reduce Fe(III) D. orientis is an obligate anaerobic microorganism and is able to reduce Fe(III). Confocal laser scanning microscopy and fluorescent lectin-binding analyses (FLBA) were used to study the arrangement and composition of the exopolysaccharides/glycoconjugates in biofilms indicating the presence of mannose, glucose, and N-acetylglucosamine residues. This study provides insights to understand the processes leading to the mobility or retention of metals in mine waste and industrial landfill environments.
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Georgieva, Tania, Marie Mikkelsen, and Birgitte Ahring. "High ethanol tolerance of the thermophilic anaerobic ethanol producer Thermoanaerobacter BG1L1." Open Life Sciences 2, no. 3 (September 1, 2007): 364–77. http://dx.doi.org/10.2478/s11535-007-0026-x.
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AbstractThe low ethanol tolerance of thermophilic anaerobic bacteria, generally less than 2% (v/v) ethanol, is one of the main limiting factors for their potential use for second generation fuel ethanol production. In this work, the tolerance of thermophilic anaerobic bacterium Thermoanaerobacter BG1L1 to exogenously added ethanol was studied in a continuous immobilized reactor system at a growth temperature of 70°C. Ethanol tolerance was evaluated based on inhibition of fermentative performance e.g. inhibition of substrate conversion. At the highest ethanol concentration tested (8.3% v/v), the strain was able to convert 42% of the xylose initially present, indicating that this ethanol concentration is not the upper limit tolerated by the strain. Long-term strain adaptation to high ethanol concentrations (6–8.3%) resulted in an improvement of xylose conversion by 25% at an ethanol concentration of 5% v/v, which is the concentration required in practice for economically efficient product recovery. For all ethanol concentrations tested, relatively high and stable ethanol yields (0.40–0.42 g/g) were seen. The strain demonstrated a remarkable ethanol tolerance, which is the second highest displayed by thermophilic anaerobic bacteria known to the authors. This appears to be the first study of the ethanol tolerance of these microorganisms in a continuous immobilized reactor system.
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Fuchsman, Clara A., Roy Eric Collins, Gabrielle Rocap, and William J. Brazelton. "Effect of the environment on horizontal gene transfer between bacteria and archaea." PeerJ 5 (September 29, 2017): e3865. http://dx.doi.org/10.7717/peerj.3865.
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BackgroundHorizontal gene transfer, the transfer and incorporation of genetic material between different species of organisms, has an important but poorly quantified role in the adaptation of microbes to their environment. Previous work has shown that genome size and the number of horizontally transferred genes are strongly correlated. Here we consider how genome size confuses the quantification of horizontal gene transfer because the number of genes an organism accumulates over time depends on its evolutionary history and ecological context (e.g., the nutrient regime for which it is adapted).ResultsWe investigated horizontal gene transfer between archaea and bacteria by first counting reciprocal BLAST hits among 448 bacterial and 57 archaeal genomes to find shared genes. Then we used the DarkHorse algorithm, a probability-based, lineage-weighted method (Podell & Gaasterland, 2007), to identify potential horizontally transferred genes among these shared genes. By removing the effect of genome size in the bacteria, we have identified bacteria with unusually large numbers of shared genes with archaea for their genome size. Interestingly, archaea and bacteria that live in anaerobic and/or high temperature conditions are more likely to share unusually large numbers of genes. However, high salt was not found to significantly affect the numbers of shared genes. Numbers of shared (genome size-corrected, reciprocal BLAST hits) and transferred genes (identified by DarkHorse) were strongly correlated. Thus archaea and bacteria that live in anaerobic and/or high temperature conditions are more likely to share horizontally transferred genes. These horizontally transferred genes are over-represented by genes involved in energy conversion as well as the transport and metabolism of inorganic ions and amino acids.ConclusionsAnaerobic and thermophilic bacteria share unusually large numbers of genes with archaea. This is mainly due to horizontal gene transfer of genes from the archaea to the bacteria.In general, these transfers are from archaea that live in similar oxygen and temperature conditions as the bacteria that receive the genes. Potential hotspots of horizontal gene transfer between archaea and bacteria include hot springs, marine sediments, and oil wells. Cold spots for horizontal transfer included dilute, aerobic, mesophilic environments such as marine and freshwater surface waters.
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Oren, Aharon. "Bioenergetic Aspects of Halophilism." Microbiology and Molecular Biology Reviews 63, no. 2 (June 1, 1999): 334–48. http://dx.doi.org/10.1128/mmbr.63.2.334-348.1999.
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SUMMARY Examinination of microbial diversity in environments of increasing salt concentrations indicates that certain types of dissimilatory metabolism do not occur at the highest salinities. Examples are methanogenesis for H2 + CO2 or from acetate, dissimilatory sulfate reduction with oxidation of acetate, and autotrophic nitrification. Occurrence of the different metabolic types is correlated with the free-energy change associated with the dissimilatory reactions. Life at high salt concentrations is energetically expensive. Most bacteria and also the methanogenic archaea produce high intracellular concentrations of organic osmotic solutes at a high energetic cost. All halophilic microorganisms expend large amounts of energy to maintain steep gradients of NA+ and K+ concentrations across their cytoplasmic membrane. The energetic cost of salt adaptation probably dictates what types of metabolism can support life at the highest salt concentrations. Use of KCl as an intracellular solute, while requiring far-reaching adaptations of the intracellular machinery, is energetically more favorable than production of organic-compatible solutes. This may explain why the anaerobic halophilic fermentative bacteria (order Haloanaerobiales) use this strategy and also why halophilic homoacetogenic bacteria that produce acetate from H2 + CO2 exist whereas methanogens that use the same substrates in a reaction with a similar free-energy yield do not.
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Silva, Franknairy G., Viridiana S. Ferreira-Leitao, and Magali C. Cammarota. "Strategies for Increasing the Biohydrogen Yield in Anaerobic Fermentation of Xylose." Environment and Natural Resources Research 9, no. 3 (June 28, 2019): 32. http://dx.doi.org/10.5539/enrr.v9n3p32.
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The pretreatment of lignocellulosic materials to obtain cellulose generates a residual stream with hemicellulosic composition, mainly containing xylose. This C5 fraction is not directly fermentable by microorganisms traditionally used to produce ethanol. Hence, more promising alternatives for the C5 fraction have been studied, and acidogenic fermentation proves to be an attractive option for the production of biohydrogen, due to the possibility of using hemicellulose fractions and mixed anaerobic cultures. To reduce the activity of hydrogen-consuming microorganisms when mixed cultures are employed as inoculum to produce hydrogen by anaerobic fermentation, thermal pretreatment was selected. However, such pretreatment method also affects the activity of hydrogen-producing acidogenic bacteria, and strategies should be studied to enrich the inoculum for these bacteria and to increase hydrogen yields. Thus, this study evaluated the effect of some strategies on the biohydrogen production from xylose. The strategies adopted were thermal pretreatment of the sludge, maintenance of the incubation temperature at 35 °C, adaptation of the sludge by successive contacts with the xylose solution, and increasing inoculum to substrate ratio (I/S) from 1 to 2. This approach improved hydrogen yield approximately 30 times, from 0.03 to 0.93 mmol H2/mmol xylose. However, this yield was only 56% of the theoretical value and can still be improved.
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Sánchez-Valeriano, Nohemí, Diana I. Romero-Mota, Erik S. Rosas-Mendoza, Eduardo Hernández-Aguilar, and Juan Manuel Méndez-Contreras. "Determination of kinetic parameters of the anaerobic biotransformation process of corn cob (Zea Mays L.) with Lactobacillus acidophilus." Renewable Energy, Biomass & Sustainability 4, no. 1 (September 28, 2022): 38–43. http://dx.doi.org/10.56845/rebs.v4i1.67.
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The cob is the residue generated from the separation of the grain from the cob, and due to its components, it is considered a lignocellulosic material, so its use is limited, which favors the burning of the cob and its spreading, thus generating a problem of environmental pollution. Probiotics are live microorganisms that, when supplied in adequate amounts, provide a beneficial effect to the host, reducing the carbohydrate content in lignocellulosic materials through fermentation, obtaining a product rich in nutrients. Therefore, this research aimed to determine the kinetic parameters of biotransformation of corn residues through the fermentative action of the probiotic bacteria Lactobacillus acidophilus. Anaerobic fermentation kinetics were performed using the bacterium Lactobacillus acidophilus at different concentrations (10 and 15% v/v) to obtain kinetic parameters of microbial growth and substrate consumption for the biotransformation of white corn (Zea MaysL.) residues. The kinetic parameters indicate that when using 15% inoculum, the bacteria adapt to a greater extent to the substrate since the Ks value was 0.5693 g/L and the adaptation time was 18.25 h, thus allowing the growth of Lactobacillus acidophilus and therefore the process of biotransformation of corn residues. While for the consumption of substrate, it was identified that the use of 10% inoculum was better since it presented a value of k of 0.2534 that is higher than the value obtained when 15% is used because the rate of substrate consumption is faster. Therefore, the dose of 15% inoculum seems to be the most suitable for the adaptation of the bacteria in the shortest time and therefore the biotransformation process is carried out.
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Yang, Ruili, Wenlong Mao, Xiaojun Wang, Zhaoji Zhang, Junbin Wu, and Shaohua Chen. "Response and Adaptation of Microbial Community in a CANON Reactor Exposed to an Extreme Alkaline Shock." Archaea 2020 (July 1, 2020): 1–11. http://dx.doi.org/10.1155/2020/8888615.
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Responses of a microbial community in the completely autotrophic nitrogen removal over nitrite (CANON) process, which was shocked by a pH of 11.0 for 12 h, were investigated. During the recovery phase, the performance, anaerobic ammonia oxidation (anammox) activity, microbial community, and correlation of bacteria as well as the influencing factors were evaluated synchronously. The performance of the CANON process deteriorated rapidly with a nitrogen removal rate (NRR) of 0.13 kg·m-3·d-1, and Firmicutes, spore-forming bacteria, were the dominant phyla after alkaline shock. However, it could self-restore within 107 days after undergoing four stages, at which Planctomycetes became dominant with a relative abundance of 64.62%. Network analysis showed that anammox bacteria (Candidatus Jettenia, Kuenenia, and Brocadia) were positively related to some functional bacteria such as Nitrosomonas, SM1A02, and Calorithrix. Canonical correspondence analysis presented a strong correlation between the microbial community and influencing factors during the recovery phase. With the increase of nitrogen loading rate, the decrease of free nitrous acid and the synergistic effects, heme c content, specific anammox activity (SAA), NRR, and the abundance of dominant genus increased correspondingly. The increase of heme c content regulates the quorum sensing system, promotes the secretion of extracellular polymeric substances, and further improves SAA, NRR, and the relative abundance of the dominant genus. This study highlights some implications for the recovery of the CANON reactor after being exposed to an alkaline shock.
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Malone, Lucia M., Hannah G. Hampton, Xochitl C. Morgan, and Peter C. Fineran. "Type I CRISPR-Cas provides robust immunity but incomplete attenuation of phage-induced cellular stress." Nucleic Acids Research 50, no. 1 (December 20, 2021): 160–74. http://dx.doi.org/10.1093/nar/gkab1210.
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Abstract During infection, phages manipulate bacteria to redirect metabolism towards viral proliferation. To counteract phages, some bacteria employ CRISPR-Cas systems that provide adaptive immunity. While CRISPR-Cas mechanisms have been studied extensively, their effects on both the phage and the host during phage infection remains poorly understood. Here, we analysed the infection of Serratia by a siphovirus (JS26) and the transcriptomic response with, or without type I-E or I-F CRISPR-Cas immunity. In non-immune Serratia, phage infection altered bacterial metabolism by upregulating anaerobic respiration and amino acid biosynthesis genes, while flagella production was suppressed. Furthermore, phage proliferation required a late-expressed viral Cas4 homologue, which did not influence CRISPR adaptation. While type I-E and I-F immunity provided robust defence against phage infection, phage development still impacted the bacterial host. Moreover, DNA repair and SOS response pathways were upregulated during type I immunity. We also discovered that the type I-F system is controlled by a positive autoregulatory feedback loop that is activated upon phage targeting during type I-F immunity, leading to a controlled anti-phage response. Overall, our results provide new insight into phage-host dynamics and the impact of CRISPR immunity within the infected cell.
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Arella, Davide, Maddalena Dilucca, and Andrea Giansanti. "Codon usage bias and environmental adaptation in microbial organisms." Molecular Genetics and Genomics 296, no. 3 (April 5, 2021): 751–62. http://dx.doi.org/10.1007/s00438-021-01771-4.
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AbstractIn each genome, synonymous codons are used with different frequencies; this general phenomenon is known as codon usage bias. It has been previously recognised that codon usage bias could affect the cellular fitness and might be associated with the ecology of microbial organisms. In this exploratory study, we investigated the relationship between codon usage bias, lifestyles (thermophiles vs. mesophiles; pathogenic vs. non-pathogenic; halophilic vs. non-halophilic; aerobic vs. anaerobic and facultative) and habitats (aquatic, terrestrial, host-associated, specialised, multiple) of 615 microbial organisms (544 bacteria and 71 archaea). Principal component analysis revealed that species with given phenotypic traits and living in similar environmental conditions have similar codon preferences, as represented by the relative synonymous codon usage (RSCU) index, and similar spectra of tRNA availability, as gauged by the tRNA gene copy number (tGCN). Moreover, by measuring the average tRNA adaptation index (tAI) for each genome, an index that can be associated with translational efficiency, we observed that organisms able to live in multiple habitats, including facultative organisms, mesophiles and pathogenic bacteria, are characterised by a reduced translational efficiency, consistently with their need to adapt to different environments. Our results show that synonymous codon choices might be under strong translational selection, which modulates the choice of the codons to differently match tRNA availability, depending on the organism’s lifestyle needs. To our knowledge, this is the first large-scale study that examines the role of codon bias and translational efficiency in the adaptation of microbial organisms to the environment in which they live.
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Damianovic, M. H. R. Z., I. K. Sakamoto, and E. Foresti. "Biofilm adaptation to sulfate reduction in anaerobic immobilized biomass reactors sujected to different COD/sulfate ratios." Water Science and Technology 54, no. 2 (July 1, 2006): 119–26. http://dx.doi.org/10.2166/wst.2006.494.
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Various aspects of biofilm adaptation to sulfate reduction in horizontal-flow anaerobic immobilized biomass (HAIB) reactors subjected to increasing sulfate concentrations and different COD/sulfate ratios are presented and discussed. Four bench-scale HAIB reactors filled with vegetal carbon (R1 and R2) and polyurethane foam matrices (R3 and R4) were utilized. Influent sulfate concentrations ranging from 500 to 3000 mg/L were applied at COD/sulfate ratios ranging from 5.0 to 1.7. Reactors R1 and R4 were operated with higher sulfate loads than those applied to R2 and R3. For the same COD/sulfate ratio, the highest sulfate reduction efficiency (∼80%) was displayed by the vegetal carbon reactor (R2) subjected to low sulfate loads. According to the results of our molecular biology analyses, the different support materials provided different biomass colonization conditions. The lowest diversity of sulfate-reducing bacteria was found in the HAIB filled with polyurethane foam matrices operating with high sulfate loads.
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Robb, Frank T., and Stephen M. Techtmann. "Life on the fringe: microbial adaptation to growth on carbon monoxide." F1000Research 7 (December 27, 2018): 1981. http://dx.doi.org/10.12688/f1000research.16059.1.
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Microbial adaptation to extreme conditions takes many forms, including specialized metabolism which may be crucial to survival in adverse conditions. Here, we analyze the diversity and environmental importance of systems allowing microbial carbon monoxide (CO) metabolism. CO is a toxic gas that can poison most organisms because of its tight binding to metalloproteins. Microbial CO uptake was first noted by Kluyver and Schnellen in 1947, and since then many microbes using CO via oxidation have emerged. Many strains use molecular oxygen as the electron acceptor for aerobic oxidation of CO using Mo-containing CO oxidoreductase enzymes named CO dehydrogenase. Anaerobic carboxydotrophs oxidize CO using CooS enzymes that contain Ni/Fe catalytic centers and are unrelated to CO dehydrogenase. Though rare on Earth in free form, CO is an important intermediate compound in anaerobic carbon cycling, as it can be coupled to acetogenesis, methanogenesis, hydrogenogenesis, and metal reduction. Many microbial species—both bacteria and archaea—have been shown to use CO to conserve energy or fix cell carbon or both. Microbial CO formation is also very common. Carboxydotrophs thus glean energy and fix carbon from a “metabolic leftover” that is not consumed by, and is toxic to, most microorganisms. Surprisingly, many species are able to thrive under culture headspaces sometimes exceeding 1 atmosphere of CO. It appears that carboxydotrophs are adapted to provide a metabolic “currency exchange” system in microbial communities in which CO arising either abiotically or biogenically is converted to CO2 and H2 that feed major metabolic pathways for energy conservation or carbon fixation. Solventogenic CO metabolism has been exploited to construct very large gas fermentation plants converting CO-rich industrial flue emissions into biofuels and chemical feedstocks, creating renewable energy while mitigating global warming. The use of thermostable CO dehydrogenase enzymes to construct sensitive CO gas sensors is also in progress.
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Herrmann, Elena, Wayne Young, Douglas Rosendale, Verena Reichert-Grimm, Christian U. Riedel, Ralf Conrad, and Markus Egert. "RNA-Based Stable Isotope Probing SuggestsAllobaculumspp. as Particularly Active Glucose Assimilators in a Complex Murine Microbiota Cultured In Vitro." BioMed Research International 2017 (2017): 1–13. http://dx.doi.org/10.1155/2017/1829685.
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RNA-based stable isotope probing (RNA-SIP) and metabolic profiling were used to detect actively glucose-consuming bacteria in a complex microbial community obtained from a murine model system. A faeces-derived microbiota was incubated under anaerobic conditions for 0, 2, and 4 h with 40 mM [U13C]glucose. Isopycnic density gradient ultracentrifugation and fractionation of isolated RNA into labeled and unlabeled fractions followed by 16S rRNA sequencing showed a quick adaptation of the bacterial community in response to the added sugar, which was dominated by unclassified Lachnospiraceae species. Inspection of distinct fractions of isotope-labeled RNA revealedAllobaculumspp. as particularly active glucose utilizers in the system, as the corresponding RNA showed significantly higher proportions among the labeled RNA. With time, the labeled sugar was used by a wider spectrum of faecal bacteria. Metabolic profiling indicated rapid fermentation of [U13C]glucose, with lactate, acetate, and propionate being the principal13C-labeled fermentation products, and suggested that “cross-feeding” occurred in the system. RNA-SIP combined with metabolic profiling of13C-labeled products allowed insights into the microbial assimilation of a general model substrate, demonstrating the appropriateness of this technology to study assimilation processes of nutritionally more relevant substrates, for example, prebiotic carbohydrates, in the gut microbiota of mice as a model system.
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Grossi, Vincent, Damien Mollex, Arnauld Vinçon-Laugier, Florence Hakil, Muriel Pacton, and Cristiana Cravo-Laureau. "Mono- and Dialkyl Glycerol Ether Lipids in Anaerobic Bacteria: Biosynthetic Insights from the Mesophilic Sulfate Reducer Desulfatibacillum alkenivorans PF2803T." Applied and Environmental Microbiology 81, no. 9 (February 27, 2015): 3157–68. http://dx.doi.org/10.1128/aem.03794-14.
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ABSTRACTBacterial glycerol ether lipids (alkylglycerols) have received increasing attention during the last decades, notably due to their potential role in cell resistance or adaptation to adverse environmental conditions. Major uncertainties remain, however, regarding the origin, biosynthesis, and modes of formation of these uncommon bacterial lipids. We report here the preponderance of monoalkyl- and dialkylglycerols (1-O-alkyl-, 2-O-alkyl-, and 1,2-O-dialkylglycerols) among the hydrolyzed lipids of the marine mesophilic sulfate-reducing proteobacteriumDesulfatibacillum alkenivoransPF2803Tgrown onn-alkenes (pentadec-1-ene or hexadec-1-ene) as the sole carbon and energy source. Alkylglycerols account for one-third to two-thirds of the total cellular lipids (alkylglycerols plus acylglycerols), depending on the growth substrate, with dialkylglycerols contributing to one-fifth to two-fifths of the total ether lipids. The carbon chain distribution of the lipids ofD. alkenivoransalso depends on that of the substrate, but the chain length and methyl-branching patterns of fatty acids and monoalkyl- and dialkylglycerols are systematically congruent, supporting the idea of a biosynthetic link between the three classes of compounds. Vinyl ethers (1-alken-1′-yl-glycerols, known as plasmalogens) are not detected among the lipids of strain PF2803T. Cultures grown on different (per)deuteratedn-alkene,n-alkanol, andn-fatty acid substrates further demonstrate that saturated alkylglycerols are not formed via the reduction of hypothetic alken-1′-yl intermediates. Our results support an unprecedented biosynthetic pathway to monoalkyl/monoacyl- and dialkylglycerols in anaerobic bacteria and suggest thatn-alkyl compounds present in the environment can serve as the substrates for supplying the building blocks of ether phospholipids of heterotrophic bacteria.
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Mueller, R. F., and A. Steiner. "Inhibition of Anaerobic Digestion Caused by Heavy Metals." Water Science and Technology 26, no. 3-4 (August 1, 1992): 835–46. http://dx.doi.org/10.2166/wst.1992.0464.
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The severity of heavy metal inhibition on anaerobic digestion is dependent on the metal species and their dissolved concentration in the digester. The general sequence of inhibition on anaerobic digestion of municipal sewage sludge was found with Ni > Cu > Cd > Cr > Pb. Metal immobilization affinity in the sludge followed the reverse sequence. Due to sulfide production during digestion high quantities of heavy metals are precipitating as highly insoluble sulfide salts. Nickel was immobilized to 94 % in the digester and indicated the most dramatic effect on anaerobic digestion. At a concentration of 250 to 300 g Ni m-3 toxicity occurred. Lower nickel concentrations resulted in reversible process inhibition. Copper up to 1000 g Cu m-3 caused reversible inhibition of acid producing, fermentative, and methanogenic bacteria. The time necessary for recovery of the process was dependent on the initial copper concentration in the digester. The organisms indicated capability of adaptation to copper. The copper uptake in the digester was 97 %. Cadmium inhibited digestion of sewage sludge up to approximately 50 % at 650 g Cd m-3. For long durations of acclimation a tendency toward recovery was observed. The cadmium uptake in the digested sludge was 99 %. Chromium and lead were uptaken at 99.9 % during digestion. Hence, the addition of these metals up to 1000 mg Cr/l and 600 mg Pb/l showed only little effect on anaerobic digestion.
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Urbanek, M., T. Strycek, C. Wyndham, and M. Goldner. "Use of a bromobenzoate for cross-adaptation of anaerobic bacteria in Lake Ontario sediments for degradation of chlorinated aromatics." Letters in Applied Microbiology 9, no. 5 (November 1989): 191–94. http://dx.doi.org/10.1111/j.1472-765x.1989.tb00322.x.
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Rattray, Jayne E., Jack van de Vossenberg, Andrea Jaeschke, Ellen C. Hopmans, Stuart G. Wakeham, Gaute Lavik, Marcel M. M. Kuypers, et al. "Impact of Temperature on Ladderane Lipid Distribution in Anammox Bacteria." Applied and Environmental Microbiology 76, no. 5 (January 4, 2010): 1596–603. http://dx.doi.org/10.1128/aem.01796-09.
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ABSTRACT Anaerobic ammonium-oxidizing (anammox) bacteria have the unique ability to synthesize fatty acids containing linearly concatenated cyclobutane rings, termed “ladderane lipids.” In this study we investigated the effect of temperature on the ladderane lipid composition and distribution in anammox enrichment cultures, marine particulate organic matter, and surface sediments. Under controlled laboratory conditions we observed an increase in the amount of C20 [5]-ladderane fatty acids compared with the amount of C18 [5]-ladderane fatty acids with increasing temperature and also an increase in the amount of C18 [5]-ladderane fatty acids compared with the amount of C20 [5]-ladderane fatty acids with decreasing temperature. Combining these data with results from the natural environment showed a significant (R 2 = 0.85, P = <0.0001, n = 121) positive sigmoidal relationship between the amounts of C18 and C20 [5]-ladderane fatty acids and the in situ temperature; i.e., there is an increase in the relative abundance of C18 [5]-ladderane fatty acids at lower temperatures and vice versa, particularly at temperatures between 12�C and 20�C. Novel shorter (C16) and longer (C22 to C24) ladderane fatty acids were also identified, but their relative amounts were small and did not change with temperature. The adaptation of ladderane fatty acid chain length to temperature changes is similar to the regulation of common fatty acid composition in other bacteria and may be the result of maintaining constant membrane fluidity under different temperature regimens (homeoviscous adaptation). Our results can potentially be used to discriminate between the origins of ladderane lipids in marine sediments, i.e., to determine if ladderanes are produced in situ in relatively cold surface sediments or if they are fossil remnants originating from the warmer upper water column.
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Klüber, Patrick, Dorothee Tegtmeier, Sabine Hurka, Janin Pfeiffer, Andreas Vilcinskas, Martin Rühl, and Holger Zorn. "Diet Fermentation Leads to Microbial Adaptation in Black Soldier Fly (Hermetia illucens; Linnaeus, 1758) Larvae Reared on Palm Oil Side Streams." Sustainability 14, no. 9 (May 6, 2022): 5626. http://dx.doi.org/10.3390/su14095626.
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Insects offer a promising alternative source of protein to mitigate the environmental consequences of conventional livestock farming. Larvae of the black soldier fly (Hermetia illucens; Linnaeus, 1758) efficiently convert a variety of organic side streams and residues into valuable proteins, lipids, and chitin. Here, we evaluated the suitability of two palm oil industry side streams—empty fruit bunches (EFB) and palm kernel meal (PKM)—as larval feed, and their impact on the larval gut microbiome. Among 69 fungal species we screened, Marasmius palmivorus, Irpex consors, and Bjerkandera adusta achieved the fastest growth and lignin degradation, so these fungi were used for the pretreatment of 7:3 mixtures of EFB and PKM. Larvae reared on the mixture pretreated with B. adusta (BAD) developed significantly more quickly and reached a higher final weight than those reared on the other pretreatments or the non-fermented reference (NFR). Amplicon sequencing of the BAD and NFR groups revealed major differences in the larval gut microbiome. The NFR group was dominated by facultatively anaerobic Enterobacteriaceae (typical of H. illucens larvae) whereas the BAD group favored obligately anaerobic, cellulolytic bacteria (Ruminococcaceae and Lachnospiraceae). We hypothesize that fungal lignin degradation led to an accumulation of mycelia and subsequent cellulolytic breakdown of fiber residues, thus improving substrate digestibility.
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Wiegel, J., and V. V. Kevbrin. "Alkalithermophiles." Biochemical Society Transactions 32, no. 2 (April 1, 2004): 193–98. http://dx.doi.org/10.1042/bst0320193.
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Alkalithermophiles are an exciting subset of extremophilic organisms and represent extremophiles that are adapted to two extreme conditions, i.e. to a combination of alkaline and thermobiotic growth conditions. Among the anaerobic alkalithermophiles are representatives of both Bacteria and Archaea within a wide variety of physiological types and systematic groups, although a great majority belongs to the Firmicutes. Alkaliphiles have been isolated from a variety of niches including mesobiotic and neutrophilic soils and sediments. Interestingly anaerobic isolates from mesobiotic and neutrophilic niches exhibit shorter doubling times than isolates from thermobiotic niches; some anaerobic alkalithermophiles exhibit extremely fast growth rates, i.e. doubling times as short as 10 min. Their adaptation to both high pH and high temperature draws our attention not only because they are potential sources of industrially valuable enzymes but also because of their adaptive mechanisms to external environmental parameters. They could thus function as model organisms for extraterrestrial life in some environments and for theories on the origin of life. Alkalithermophiles, as far we know, do not represent the most thermophilic nor the most alkaliphilic of micro-organisms but represent the most alkaliphilic ones among the thermophiles and vice versa. We believe that the presently known species are only the tip of the iceberg and therefore that they do not represent the true boundaries under which life can thrive in respect to high temperature in alkaline environments.
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Erdal, U. G., Z. K. Erdal, and C. W. Randall. "A thermal adaptation of bacteria to cold temperatures in an enhanced biological phosphorus removal system." Water Science and Technology 47, no. 11 (June 1, 2003): 123–28. http://dx.doi.org/10.2166/wst.2003.0595.
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Temperature is one of the key parameters that affects the reaction kinetics and performance of enhanced biological phosphorus removal (EBPR) systems. Although studies agree regarding the effect of temperature on kinetic reaction rates, there are contradictory results in the literature regarding the effect of temperature on EBPR system performance. Early investigators (Sell, Ekama et al., Daigger et al.) reported better performance with lower temperatures, but others have reported partial or complete loss of EBPR functions at low temperatures (McClintock et al., Brdjanovic et al., Beatons et al.). One speculation is that deterioration in the EBPR system performance at cold temperatures can be attributed to rigid-like behavior of the cell membranes. Most cells (not all) on the other hand have the ability to alter their membrane fatty acid composition as temperature changes in order to keep their membrane at nearly the same fluidity despite the temperature changes. This unique ability is known as homeoviscous adaptation. In this study, homeoviscous adaptation by EBPR activated sludge was investigated for a series of temperatures ranging from 20°C to 5°C using a lab scale continuous flow EBPR system fed with acetate and supplemental yeast extract. The fatty acid analysis results suggested that the unsaturated to saturated fatty acid ratio increased from 1.40 to 3.61 as temperature dropped from 20 to 5°C. The increased cis-9-hexadecanoic acid (C16:1) at 5°C strongly indicated the presence of homeoviscous adaptation in the EBPR bacterial community. Thus the cell membranes of the EBPR community were still in a fluid state, and solute transport and proton motive force were operable even at 5°C. It was concluded that loss of EBPR performance at low temperatures is not related to the physical state of the cellular membranes, but is possibly related to the application of unsuitable operational conditions (low SRT, excessive electron acceptors, low anaerobic detention time, non-acclimated sludge, etc.).
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Salina, Elena G., Simon J. Waddell, Nadine Hoffmann, Ida Rosenkrands, Philip D. Butcher, and Arseny S. Kaprelyants. "Potassium availability triggers Mycobacterium tuberculosis transition to, and resuscitation from, non-culturable (dormant) states." Open Biology 4, no. 10 (October 2014): 140106. http://dx.doi.org/10.1098/rsob.140106.
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Dormancy in non-sporulating bacteria is an interesting and underexplored phenomenon with significant medical implications. In particular, latent tuberculosis may result from the maintenance of Mycobacterium tuberculosis bacilli in non-replicating states in infected individuals. Uniquely, growth of M. tuberculosis in aerobic conditions in potassium-deficient media resulted in the generation of bacilli that were non-culturable (NC) on solid media but detectable in liquid media. These bacilli were morphologically distinct and tolerant to cell-wall-targeting antimicrobials. Bacterial counts on solid media quickly recovered after washing and incubating bacilli in fresh resuscitation media containing potassium. This resuscitation of growth occurred too quickly to be attributed to M. tuberculosis replication. Transcriptomic and proteomic profiling through adaptation to, and resuscitation from, this NC state revealed a switch to anaerobic respiration and a shift to lipid and amino acid metabolism. High concordance with mRNA signatures derived from M. tuberculosis infection models suggests that analogous NC mycobacterial phenotypes may exist during disease and may represent unrecognized populations in vivo . Resuscitation of NC bacilli in potassium-sufficient media was characterized by time-dependent activation of metabolic pathways in a programmed series of processes that probably transit bacilli through challenging microenvironments during infection.
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Eschbach, Martin, Henrik Möbitz, Alexandra Rompf, and Dieter Jahn. "Members of the genus Arthrobacter grow anaerobically using nitrate ammonification and fermentative processes: anaerobic adaptation of aerobic bacteria abundant in soil." FEMS Microbiology Letters 223, no. 2 (June 2003): 227–30. http://dx.doi.org/10.1016/s0378-1097(03)00383-5.
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Nagel, P., A. Urtubia, G. Aroca, R. Chamy, and M. Schiappacasse. "Methanogenic Toxicity and Anaerobic Biodegradation of Chemical Products in Use in a Brewery." Water Science and Technology 40, no. 8 (October 1, 1999): 169–76. http://dx.doi.org/10.2166/wst.1999.0414.
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Brewery industry effluents, as any other industrial effluent, contain a number of chemical products that could be toxic in biological wastewater treatment plants. Most of these products come from clean in place (CIP) systems, i.e. detergents and disinfectant, and from lubrication systems. To evaluate the toxicity effect of these compounds on an anaerobic effluent treatment pilot plant, studies of methanogenic activity were carried out. The results showed that the synthetic lubricant evaluated had a high toxicity level, compared to the organic lubricant; the disinfectant showed inhibition to some extent. To decrease the toxicity effect, the recovery and reutilization of these chemicals are suggested. Experiments to study the feasibility of adapting anaerobic sludge to these compounds were carried out. Working with UASB reactors, the adaptation of the sludge takes place in the presence of the most toxic chemical products; certain inhibition was observed on methanogenic bacteria in the reactor where a disinfectant was added, even though there was sludge wash out. In general a decrease in the operational behaviour was observed after adding the compound, a new steady state was reached in absence of the toxic compounds, in terms of alkalinity ratio, removal of COD, methane production. The reactors were able to be recovered and to be adapted again.
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Winanti, Widiatmini Sih, Prasetiyadi Prasetiyadi, and Wiharja Wiharja. "Pengolahan Palm Oil Mill Effluent (POME) menjadi Biogas dengan Sistem Anaerobik Tipe Fixed Bed tanpa Proses Netralisasi." Jurnal Teknologi Lingkungan 20, no. 1 (January 31, 2019): 143. http://dx.doi.org/10.29122/jtl.v20i1.3248.
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ABSTRACTPalm Oil Mill wastewater or POME is currently not fully utilized. POME waste treatment generally uses covered lagoon technology using the anaerobic system, which generally operates well in neutral waste conditions with a pH of 7 and uses mesophilic processes at temperatures around 35oC. So it is necessary to cool down and neutralize before POME is fed to the reactor, by mixing it with POME which has been degraded inside the reactor, where the pH condition has to turn into a base. It is useful to ensure that the POME temperature before being fed into the reactor is near the ambient temperature and the acidity of POME is near neutral (pH = 7). POME treatment using a covered lagoon reactor usually need 30 days residence time. The Fixed Bed anaerobic reactor is capable to treat waste with a low pH waste, so POME which has a pH of 4 does not need to be neutralized before treating using Fixed Bed Reactor. This will simplify the processing process, reduce investment costs and operating costs. The purpose of this research is to process POME waste using an anaerobic type Fixed Bed reactor without neutralization stage. The method processing using Fixed Bed type reactor is divided into two stages of a process that is bacteria inoculation process and POME waste adaptation process. The results of the research can reduce the HRT to 2o days, with optimal POME feeding at 150 liters/day. The percentage of methane gas measured was 66%. The methane gas yield is 0.52 liters/gram of COD or greater than the results of using the covered lagoon, which is 0.35 liters/ gram COD.Key word: Palm Oil Mill Effluent (POME), anaerobic, Fixed Bed, biogas, neutralizationABSTRAKLimbah cair industri minyak kelapa sawit atau POME saat ini belum dimanfaatkan secara maksimal. Pengolahan limbah POME umumnya menggunakan teknologi covered lagoon dengan sistem anaerobik, dimana umumnya teknologi ini beroperasi baik pada kondisi limbah yang netral dengan pH 7 dan menggunakan proses mesopilik pada suhu sekitar 35oC. Sehingga diperlukan tahap pendinginan dan tahap netralisasi terlebih dahulu sebelum POME diumpankan ke reaktor, yaitu dengan mencampurkannya dengan POME yang sudah terdegradasi di dalam reaktor, karena sifatnya sudah berubah menjadi basa. Hal ini berguna untuk memastikan bahwa suhu POME sebelum masuk reaktor sudah mendekati suhu lingkungan dan tingkat keasaman POME sudah mendekati netral (pH =7). Pengolahan POME menggunakan covered lagoon umumnya memerlukan waktu tinggal di dalam reaktor(HRT) sekitar 30 hari. Reaktor anaerobik tipe Fixed Bed mampu mengolah limbah dengan pH rendah, sehingga POME yang mempunyai pH 4, tidak perlu dinetralkan terlebih dahulu. Hal ini akan menyederhanakan proses pengolahan, menurunkan biaya investasi dan biaya operasi. Tujuan penelitian ini adalah mengolah limbah POME dengan menggunakan reaktor anaerobik tipe Fixed Bed tanpa tahap proses netralisasi. Metode pengolahan anaerobik dengan menggunakan reaktor tipe Fixed Bed, terbagi menjadi dua tahapan proses yaitu proses inokulasi bakteri dan proses adaptasi limbah POME. Hasil penelitian dapat menurunkan HRT menjadi 20 hari, dengan pengumpanan POME optimal pada 150 liter/hari. Persentase gas metana adalah 66%. Hasil produksi gas metana adalah 0,52 liter/gram COD atau lebih besar dari hasil proses menggunakan covered lagoon, yaitu 0,35 liter/ gram COD.Kata Kunci: Palm Oil Mill Effluent (POME), anaerobik, Fixed Bed, biogas, netralisasi
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Sokolenko, V. L. "INDICATORS OF THE SKIN MICROBIOTA AND THE PHAGOCYTIC ACTIVITY IN MEAT AND EGG PRODUCTION WORKERS." Biotechnologia Acta 15, no. 4 (August 31, 2022): 41–43. http://dx.doi.org/10.15407/biotech15.04.041.
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Aim. The analysis of the indicators of skin microbiota and phagocytic activity of neutrophils and monocytes in employees of the "Peremoga Nova" poultry farm. Methods. The presence of sanitary and epidemiologically important groups of bacteria and the number of mesophilic aerobic and facultative anaerobic microorganisms (MAFAnM) on the skin surface, leukogram parameters and phagocytic activity of professional phagocytes were determined. The indicators of students of the Bohdan Khmelnytsky National University of Cherkasy were used as a control. Results. It was found that the MAFAnM index in the experimental group (3.2×103 CFU/cm3) is significantly lower than in the control group (2.7×103 CFU/cm3), however, the percentage of Staphylococcus spp. carriers is higher (67.5% versus 40.0%). In the experimental group, the relative and total number of monocytes is significantly higher compared to the control group. There is a positive correlation between the phagocytic number and the phagocytic index of monocytes and the value of MAFAnM. Conclusions. There was an increase of the level of monocytes in meat and egg products workers against the background of the presence of bacteria of the Staphylococcus spp. group on the skin. It may indicate the activation of pro-inflammatory factors at the level of peripheral blood. An increased percentage of staphylococcal carriers is a sign of adaptation of Staphylococcus spp. bacteria to the antibiotics used in the manufacturing process.
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Graves, Joseph L., Akamu J. Ewunkem, Jason Ward, Constance Staley, Misty D. Thomas, Kristen L. Rhinehardt, Jian Han, and Scott H. Harrison. "Experimental evolution of gallium resistance in Escherichia coli." Evolution, Medicine, and Public Health 2019, no. 1 (January 1, 2019): 169–80. http://dx.doi.org/10.1093/emph/eoz025.
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Abstract Background and Objectives Metallic antimicrobial materials are of growing interest due to their potential to control pathogenic and multidrug-resistant bacteria. Yet we do not know if utilizing these materials can lead to genetic adaptations that produce even more dangerous bacterial varieties. Methodology Here we utilize experimental evolution to produce strains of Escherichia coli K-12 MG1655 resistant to, the iron analog, gallium nitrate (Ga(NO3)3). Whole genome sequencing was utilized to determine genomic changes associated with gallium resistance. Computational modeling was utilized to propose potential molecular mechanisms of resistance. Results By day 10 of evolution, increased gallium resistance was evident in populations cultured in medium containing a sublethal concentration of gallium. Furthermore, these populations showed increased resistance to ionic silver and iron (III), but not iron (II) and no increase in traditional antibiotic resistance compared with controls and the ancestral strain. In contrast, the control populations showed increased resistance to rifampicin relative to the gallium-resistant and ancestral population. Genomic analysis identified hard selective sweeps of mutations in several genes in the gallium (III)-resistant lines including: fecA (iron citrate outer membrane transporter), insl1 (IS30 tranposase) one intergenic mutations arsC →/→ yhiS; (arsenate reductase/pseudogene) and in one pseudogene yedN ←; (iapH/yopM family). Two additional significant intergenic polymorphisms were found at frequencies > 0.500 in fepD ←/→ entS (iron-enterobactin transporter subunit/enterobactin exporter, iron-regulated) and yfgF ←/→ yfgG (cyclic-di-GMP phosphodiesterase, anaerobic/uncharacterized protein). The control populations displayed mutations in the rpoB gene, a gene associated with rifampicin resistance. Conclusions This study corroborates recent results observed in experiments utilizing pathogenic Pseudomonas strains that also showed that Gram-negative bacteria can rapidly evolve resistance to an atom that mimics an essential micronutrient and shows the pleiotropic consequences associated with this adaptation. Lay summary We utilize experimental evolution to produce strains of Escherichia coli K-12 MG1655 resistant to, the iron analog, gallium nitrate (Ga(NO3)3). Whole genome sequencing was utilized to determine genomic changes associated with gallium resistance. Computational modeling was utilized to propose potential molecular mechanisms of resistance.
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Schuler, A. J., N. Majed, V. Bucci, F. L. Hellweger, Y. Tu, and A. Z. Gu. "Is the whole the sumof its parts? Agent-basedmodelling of wastewater treatment systems." Water Science and Technology 63, no. 8 (April 1, 2011): 1590–98. http://dx.doi.org/10.2166/wst.2011.218.
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Agent-based models (ABMs) simulate individual units within a system, such as the bacteria in a biological wastewater treatment system. This paper outlines past, current and potential future applications of ABMs to wastewater treatment. ABMs track heterogeneities within microbial populations, and this has been demonstrated to yield different predictions of bulk behaviors than the conventional, “lumped” approaches for enhanced biological phosphorus removal (EBPR) completely mixed reactors systems. Current work included the application of the ABM approach to bacterial adaptation/evolution, using the model system of individual EBPR bacteria that are allowed to evolve a kinetic parameter (maximum glycogen storage) in a competitive environment. The ABM approach was successfully implemented to a simple anaerobic-aerobic system and it was found the differing initial states converged to the same optimal solution under uncertain hydraulic residence times associated with completely mixed hydraulics. In another study, an ABM was developed and applied to simulate the heterogeneity in intracellular polymer storage compounds, including polyphosphate (PP), in functional microbial populations in enhanced biological phosphorus removal (EBPR) process. The simulation results were compared to the experimental measurements of single-cell abundance of PP in polyphosphate accumulating organisms (PAOs), performed using Raman microscopy. The model-predicted heterogeneity was generally consistent with observations, and it was used to investigate the relative contribution of external (different life histories) and internal (biological) mechanisms leading to heterogeneity. In the future, ABMs could be combined with computational fluid dynamics (CFD) models to understand incomplete mixing, more intracellular states and mechanisms can be incorporated, and additional experimental verification is needed.
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Ayyed, Abbas Kadhim. "Converting Carbon Dioxide in to Methane Gas and Enhance Oil Recovery by using Biotechnology Process." Journal of Petroleum Research and Studies 12, no. 1 (March 20, 2022): 242–66. http://dx.doi.org/10.52716/jprs.v12i1.601.
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Using biotechnology in petroleum industry has many advantages .for example , Microbiologically Enhanced Oil Recovery (MEOR) increase of the productivity of the oil field and decrease the viscosity of the crude oil . It's known that atmosphere has considerable amount of CO2 gas as a result of industrial activities (crude oil production). CO2 gas plays a role in increasing atmosphere temperature and causing global warming. Bioremediation is a viable Biotechnology function for Re-producing depleted wells and global warming. It means Bioremediation uses metabolic adaptation of microorganism, a promising approach, using this technique employs of Methanogenic bacteria to convert CO2 gas in to CH4. Therefore turns carbon dioxide in to carbon which is added to crude oil (so contribute decrease the viscosity for heavy crude oil, This mechanism is a part of the promotion of oil production.it is apart an operation EOR. and Second reacts with Hydrogen by Bacteria to produce methane gas. The aim study, advantage this method increase production. and removal global warming. In this review, we discuss the role of Methanogenic bacteria in transforming CO2 gas into methane gas , that it has a role in crude oil production . Methanogenic bacteria have an important role in petroleum industry and environment during decreasing CO2 amount in the atmosphere and increasing reservoir pressure. MEOR technology uses strains that have a role in crude oil production; these bacterial strains produce biogases (Methane) that increase reservoir pressure. In this study, six strains were isolated from Rumaila oilfield, south of Iraq. These strains were identified based on microscopic and morphological observations. These strains were Methanogenic bacteria. The main part of this study includes identification of bacteria that can consume CO2 gas and making continual lab experiments to isolate and determine the best genus to do this process in oil field. Experiments were done in specific bio-labs for two years, Methanogenic bacteria strains were isolated by using specific selective growth media. The second part of this study is using these strains for bioremediation process of oil wells, which includes providing anaerobic conditions for these strains to transform CO2 gas to methane . Morphological and microscopic observations were conducted to these strains and showed the best kind of these strains according to the ability of transformation of CO2 to methane. The isolated bacteria were called BRS11 strain showed high efficiency in transformation of CO2 to methane.
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Razo-Flores, Elías, Maurice Luijten, Brian Donlon, Gatze Lettinga, and Jim Field. "Biodegradation of selected azo dyes under methanogenic conditions." Water Science and Technology 36, no. 6-7 (September 1, 1997): 65–72. http://dx.doi.org/10.2166/wst.1997.0576.
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Biological treatment of wastewaters discharged by the textile industry could potentially be problematic due to the high toxicity and recalcitrance of the commonly-used azo dye compounds. In the present report, the fate of two azo dyes under methanogenic conditions was studied. Mordant Orange 1 (MO1) and Azodisalicylate (ADS) were completely reduced and decolorised in continuous UASB reactors in the presence of cosubstrates. In the MO1 reactor, both 5-aminosalicylic acid (5-ASA) and 1,4-phenylenediamine were identified as products of azo cleavage. After long adaptation periods, 5-ASA was detected at trace levels, indicating further mineralization. ADS, a pharmaceutical azo dye constructed from two 5-ASA units, was completely mineralized even in the absence of cosubstrate, indicating that the metabolism of 5-ASA could provide the reducing equivalents needed for the azo reduction. Batch experiments confirmed the ADS mineralization. These results demonstrate that some azo dyes could serve as a carbon, energy, and nitrogen source for anaerobic bacteria.
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Fombelle, A. de, M. Varloud, A. G. Goachet, E. Jacotot, C. Philippeau, C. Drogoul, and V. Julliand. "Characterization of the microbial and biochemical profile of the different segments of the digestive tract in horses given two distinct diets." Animal Science 77, no. 2 (October 2003): 293–304. http://dx.doi.org/10.1017/s1357729800059038.
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AbstractA first group of three horses was given diet 1 (D1) allowing 1180 g per 100 kg body weight (BW) of a pelleted food rich in fibre (P1) and 556 g per 100 kg BW of straw during a 20-day period to allow for adaptation. A second group of four horses were given diet 2 (D2) allowing 1180 g per 100 kg BW of a pelleted food rich in cereals (P2) and 1000 g per 100 kg BW of meadow hay during the same period. Digesta was collected from the stomach, duodenum, jejunum, ileum, caecum, right ventral colon, left ventral colon, left dorsal colon, right dorsal colon, and small colon, and faeces were collected under general anaesthesia 2·5 h after the ingestion of the morning pelleted meal. The concentration of total anaerobic, cellulolytic and lactic acid-utilizing bacteria, lactobacilli and streptococci were determined in all these segments except for the duodenum, left ventral colon, right dorsal colon and small colon. D-/L-lactic acid, volatile fatty acids and pH were measured in all anatomic segments of the digestive tract (from stomach to small colon). The caecal concentration of total anaerobic bacteria was the lowest (7·9 5 107colony-forming units (c f. u.) per ml), whereas that of the stomach was the highest (1·4 5 109c f. u. per ml) (P< 0·001). Cellulolytic bacteria did not exceed 3·0 5 102c f u. per ml in the ante-caecal segments whereas in the hindgut the average concentration was 5·3 x 105c f u. per ml (P< 0·001). Likewise, VFA concentrations were also greater in the large intestine (on average, 96·3 mmol/l v. 8·8 mmol/l in the ante-caecal segments) (P< 0·001), confirming the limited extent of fibre degradation in these ante-caecal segments. Lactobacilli, streptococci and lactate-utilizing bacteria colonized all the digestive tract; the stomach and the small intestine tended to host the greatest numbers of these bacteria, which suggests a high interference of micro-organisms with the digestion of readily fermentable carbohydrates. Compared with the other ante-caecal segments, the stomach ecosystem seemed the most affected by the composition of the last pelleted meal ingested: the concentrations of lactobacilli and lactate-utilizing bacteria were higher (P< 0·05) with P2. The lower concentration of D-/L-lactate with P2 (P< 0·05) was concomitant with a greater proportion of propionate (P< 0·05), probably related to a greater fermentation of lactate. In the large intestine of horses given D2, cellulolytic bacteria tended to be lower, whereas VFA concentrations were higher (P < 0·05). The lower [NDF/starch] ratio of D2 was probably less propitious for the proliferation of cellulolytic bacteria but was compensated by the higher cellulose intake brought by the hay.
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Kasimatis, Gabriela, Sorel Fitz-Gibbon, Shuta Tomida, Marthew Wong, and Huiying Li. "Analysis of Complete Genomes ofPropionibacterium acnesReveals a Novel Plasmid and Increased Pseudogenes in an Acne Associated Strain." BioMed Research International 2013 (2013): 1–11. http://dx.doi.org/10.1155/2013/918320.
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The human skin harbors a diverse community of bacteria, including the Gram-positive, anaerobic bacteriumPropionibacterium acnes.P. acneshas historically been linked to the pathogenesis of acne vulgaris, a common skin disease affecting over 80% of all adolescents in the US. To gain insight into potentialP. acnespathogenic mechanisms, we previously sequenced the complete genome of aP. acnesstrain HL096PA1 that is highly associated with acne. In this study, we compared its genome to the first published complete genome KPA171202. HL096PA1 harbors a linear plasmid, pIMPLE-HL096PA1. This is the first describedP. acnesplasmid. We also observed a five-fold increase of pseudogenes in HL096PA1, several of which encode proteins in carbohydrate transport and metabolism. In addition, our analysis revealed a few island-like genomic regions that are unique to HL096PA1 and a large genomic inversion spanning the ribosomal operons. Together, these findings offer a basis for understandingP. acnesvirulent properties, host adaptation mechanisms, and its potential role in acne pathogenesis at the strain level. Furthermore, the plasmid identified in HL096PA1 may potentially provide a new opportunity forP. acnesgenetic manipulation and targeted therapy against specific disease-associated strains.
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Valero, Antonio, Elena Olague, Eduardo Medina-Pradas, Antonio Garrido-Fernández, Verónica Romero-Gil, María Jesús Cantalejo, Rosa María García-Gimeno, Fernando Pérez-Rodríguez, Guiomar Denisse Posada-Izquierdo, and Francisco Noé Arroyo-López. "Influence of Acid Adaptation on the Probability of Germination of Clostridium sporogenes Spores Against pH, NaCl and Time." Foods 9, no. 2 (January 24, 2020): 127. http://dx.doi.org/10.3390/foods9020127.
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The Clostridium sp. is a large group of spore-forming, facultative or strictly anaerobic, Gram-positive bacteria that can produce food poisoning. The table olive industry is demanding alternative formulations to respond to market demand for the reduction of acidity and salt contents in final products. while maintaining the appearance of freshness of fruits. In this work, logistic regression models for non-adapted and acid-adapted Clostridium sp. strains were developed in laboratory medium to study the influence of pH, NaCl (%) and time on the probability of germination of their spores. A Clostridium sporogenes cocktail was not able to germinate at pH < 5.0, although the adaptation of the strains produced an increase in the probability of germination at 5.0–5.5 pH levels and 6% NaCl concentration. At acidic pH values (5.0), the adapted strains germinated after 10 days of incubation, while those which were non-adapted required 15 days. At pH 5.75 and with 4% NaCl, germination of the adapted strains took place before 7 days, while several replicates of the non-adapted strains did not germinate after 42 days of storage. The model was validated in natural green olive brines with good results (>81.7% correct prediction cases). The information will be useful for the industry and administration to assess the safety risk in the formulation of new processing conditions in table olives and other fermented vegetables.
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Rajagopal, Rajinikanth, Seyyed Ebrahim Mousavi, Bernard Goyette, and Suman Adhikary. "Coupling of Microalgae Cultivation with Anaerobic Digestion of Poultry Wastes: Toward Sustainable Value Added Bioproducts." Bioengineering 8, no. 5 (May 4, 2021): 57. http://dx.doi.org/10.3390/bioengineering8050057.
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Third generation biofuels and high-value bioproducts produced from microalgal biomass have been considered promising long-term sustainable alternatives for energy and/or food production, potentially decreasing greenhouse gas emissions. Microalgae as a source of biofuels have been widely studied for bioethanol/biodiesel/biogas production. However, critical research is needed in order to increase the efficiency of microalgae production from high-N agri-waste, not only for biofuels but also for bio-based products, and thus enhance its commercial viability. The growth in the poultry industry has led to increased chicken manure (CM), which are rich in ammonia, phosphate, potassium, and other trace elements. These constituents could be used as nutrients for growing microalgae. In this research, a two-stage (liquid–solid) anaerobic digester treating CM at 20 ± 1 °C was performed, and liquid digestate (leachate) obtained after the digestion process was used as a substrate to grow the microalgal strain Chlorella vulgaris CPCC 90. Considering the high-N content (NH3-N: 5314 mg/L; TKN: 6197 mg/L) in liquid digestate, different dilutions were made, using distilled water to obtain viz. 10%, 30%, 50%, 70%, 90%, and 100% of the digestate concentrations for the microalgae cultivation. Preliminary results showed that Chlorella vulgaris CPCC 90 was able to grow and utilize nutrients from a 10% diluted CM digestate. Future research is underway to enhance microalgal growth at higher digestate concentrations and to optimize the use of microalgae/microalgae-bacteria consortia for better adaptation to high-N content wastes. An AD-microalgae coupling scenario has been proposed for the circulation bioeconomy framework.
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Sanmartín, Patricia, and Pilar Bosch-Roig. "Biocleaning to Remove Graffiti: A Real Possibility? Advances towards a Complete Protocol of Action." Coatings 9, no. 2 (February 8, 2019): 104. http://dx.doi.org/10.3390/coatings9020104.
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The first academic studies on the use of microorganisms in cleaning procedures appeared in the late 1980s/early 1990s. In the past thirty years, most of such studies have addressed the removal of nitrate and sulphate salts and organic matter from surfaces by using non-pathogenic anaerobic microorganisms, mainly sulphate-reducing bacteria. The successful use of microbes in the removal of graffiti paint remains, however, a work in progress. Biocleaning surfaces to remove graffiti is not a simple task, because of the complex chemical composition of graffiti paints. This study looks at ways of improving the bioremoval of graffiti and presents the latest findings regarding different methodological aspects of cleaning natural and man-made stone. Granite and concrete substrates were coated with silver and black graffiti spray paints for comparison of the efficacy of the biocleaning method on these different materials. Visual and microscopic examination along with colour and infrared measurements made after application of the bacterial strains tested (previously shown to be suitable candidates for bioremoval of graffiti) revealed remarkably successful results. The findings presented thus represent progress in the development of a biocleaning protocol applicable to the in-situ removal of graffiti. Important improvements have been made regarding the time of treatment, which has been reduced by up to 20 days, and the use of a culture medium enriched with powdered graffiti, which facilitates and accelerates the adaptation of the microorganisms to the target surface.