Journal articles: 'Autotrophic production'

1

Oh, S. E., K. S. Kim, H. C. Choi, J. Cho, and I. S. Kim. "Kinetics and physiological characteristics of autotrophic dentrification by denitrifying sulfur bacteria." Water Science and Technology 42, no. 3-4 (August 1, 2000): 59–68. http://dx.doi.org/10.2166/wst.2000.0359.

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To study the kinetics and physiology of autotrophic denitrifying sulfur bacteria, a steady-state anaerobic master culture reactor (MCR) was operated for over six months under a semi-continuous mode and nitrate limiting conditions using nutrient/mineral/buffer (NMB) medium containing thiosulfate and nitrate. Characteristics of the autotropic denitrifier were investigated through the cumulative gas production volume and rate, measured using an anaerobic respirometer, and through the nitrate, nitrite, and sulfate concentrations within the media. The bio-kinetic parameters were obtained based upon the Monod equation using mixed cultures in the MCR. Nonlinear regression analysis was employed using nitrate depletion and biomass production curves. Although this analysis did not yield exact biokinetic parameter estimates, the following ranges for the parameter values were obtained: μmax =0.12-0.2 hr-1; k=0.3-0.4 hr-1; Ks=3-10mg/L; YNO3=0.4-0.5mg Biomass/mg NO3--N. Inhibition of denitrification occurred when the concentrations of NO3--N, and SO42- reached about 660mg/L and 2,000mg/L, respectively. The autotrophic denitrifying sulfur bacteria were observed to be very sensitive to nitrite but relatively tolerant of nitrate, sulfate, and thiosulfate. Under mixotrophic conditions, denitrification by these bacteria occurred autotrophically; even with as high as 2 g COD, autotrophic denitrification was not significantly affected. The optimal pH and temperature for autotrophic denitrification was about 6.5–7.5 and 33–35 °C, respectively.

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Duarte, Carlos M., and Just Cebrián. "The fate of marine autotrophic production." Limnology and Oceanography 41, no. 8 (December 1996): 1758–66. http://dx.doi.org/10.4319/lo.1996.41.8.1758.

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Gifuni, Imma, Giuseppe Olivieri, Antonino Pollio, Telma Teixeira Franco, and Antonio Marzocchella. "Autotrophic starch production by Chlamydomonas species." Journal of Applied Phycology 29, no. 1 (September 4, 2016): 105–14. http://dx.doi.org/10.1007/s10811-016-0932-2.

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Frolov, Evgenii N., Ilya V. Kublanov, Stepan V. Toshchakov, Evgenii A. Lunev, Nikolay V. Pimenov, Elizaveta A. Bonch-Osmolovskaya, Alexander V. Lebedinsky, and Nikolay A. Chernyh. "Form III RubisCO-mediated transaldolase variant of the Calvin cycle in a chemolithoautotrophic bacterium." Proceedings of the National Academy of Sciences 116, no. 37 (August 26, 2019): 18638–46. http://dx.doi.org/10.1073/pnas.1904225116.

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The Calvin–Benson–Bassham (CBB) cycle assimilates CO2for the primary production of organic matter in all plants and algae, as well as in some autotrophic bacteria. The key enzyme of the CBB cycle, ribulose-bisphosphate carboxylase/oxygenase (RubisCO), is a main determinant of de novo organic matter production on Earth. Of the three carboxylating forms of RubisCO, forms I and II participate in autotrophy, and form III so far has been associated only with nucleotide and nucleoside metabolism. Here, we report that form III RubisCO functions in the CBB cycle in the thermophilic chemolithoautotrophic bacteriumThermodesulfobium acidiphilum,a phylum-level lineage representative. We further show that autotrophic CO2fixation inT. acidiphilumis accomplished via the transaldolase variant of the CBB cycle, which has not been previously demonstrated experimentally and has been considered unlikely to occur. Thus, this work reveals a distinct form of the key pathway of CO2fixation.

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Trentin, Giulia, Veronica Lucato, Eleonora Sforza, and Alberto Bertucco. "Stabilizing autotrophic cyanophycin production in continuous photobioreactors." Algal Research 60 (December 2021): 102518. http://dx.doi.org/10.1016/j.algal.2021.102518.

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Olivieri, Giuseppe, Renato S. Coellho, Telma T. Franco, Antonino Pollio, and Antonio Marzocchella. "Polysaccharides production by autotrophic cultures of microalgae." New Biotechnology 31 (July 2014): S17. http://dx.doi.org/10.1016/j.nbt.2014.05.1651.

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Jeong, Byoung Kyong, Kazuhiro Fujiwara, and Toyoki Kozai. "Carbon Dioxide Enrichment in Autotrophic Micropropagation: Methods and Advantages." HortTechnology 3, no. 3 (July 1993): 332–34. http://dx.doi.org/10.21273/horttech.3.3.332.

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Autotrophic micropropagation has advantages over conventional micropropagation and can reduce costs of plantlet production. In this article, we describe advantages of autotrophic micropropagation and a practical and formulated method of enriching culture rooms with CO2.

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Geertz-Hansen, O., C. Montes, C. M. Duarte, K. Sand-Jensen, N. Marbá, and P. Grillas. "Ecosystem metabolism in a temporary Mediterranean marsh (Doñana National Park, SW Spain)." Biogeosciences Discussions 7, no. 4 (August 26, 2010): 6495–521. http://dx.doi.org/10.5194/bgd-7-6495-2010.

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Abstract. The metabolic balance of the open waters supporting submerged macrophytes of the Doñana marsh (SW Spain) was investigated in spring, when community production is highest. The marsh community was net autotrophic with net community production rates averaging 0.61 g C m−2 d−1, and gross production rates exceeding community respiration rates by, on average, 43%. Net community production increased greatly with increasing irradiance, with the threshold irradiance for communities to become net autotrophic being 42 to 255 μE m−2 s−1, below which communities became net heterotrophic. Examination of the contributions of the benthic and the pelagic compartments showed the pelagic compartment to be strongly heterotrophic (average P/R ratio = 0.27), indicating that the metabolism of the pelagic compartment is strongly subsidised by excess organic carbon produced in the strongly autotrophic benthic compartment (average P/R = 1.58).

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Geertz-Hansen, O., C. Montes, C. M. Duarte, K. Sand-Jensen, N. Marbá, and P. Grillas. "Ecosystem metabolism in a temporary Mediterranean marsh (Doñana National Park, SW Spain)." Biogeosciences 8, no. 4 (April 19, 2011): 963–71. http://dx.doi.org/10.5194/bg-8-963-2011.

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Abstract. The metabolic balance of the open waters supporting submerged macrophytes of the Doñana marsh (SW Spain) was investigated in spring, when community production is highest. The marsh community (benthic + pelagic) was net autotrophic with net community production rates averaging 0.61 g C m−2 d−1, and gross production rates exceeding community respiration rates by, on average, 43%. Net community production increased greatly with increasing irradiance, with the threshold irradiance for communities to become net autotrophic ranging from 42 to 255 μE m−2 s−1, with net heterotrophic at lower irradiance. Examination of the contributions of the benthic and the pelagic compartments showed the pelagic compartment to be strongly heterotrophic (average P/R ratio = 0.27), indicating that the metabolism of the pelagic compartment is highly subsidised by excess organic carbon produced in the strongly autotrophic benthic compartment (average P/R = 1.58).

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Ronan, Patrick, Otini Kroukamp, Steven N. Liss, and Gideon Wolfaardt. "Interaction between CO2-consuming autotrophy and CO2-producing heterotrophy in non-axenic phototrophic biofilms." PLOS ONE 16, no. 6 (June 15, 2021): e0253224. http://dx.doi.org/10.1371/journal.pone.0253224.

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As the effects of climate change become increasingly evident, the need for effective CO2 management is clear. Microalgae are well-suited for CO2 sequestration, given their ability to rapidly uptake and fix CO2. They also readily assimilate inorganic nutrients and produce a biomass with inherent commercial value, leading to a paradigm in which CO2-sequestration, enhanced wastewater treatment, and biomass generation could be effectively combined. Natural non-axenic phototrophic cultures comprising both autotrophic and heterotrophic fractions are particularly attractive in this endeavour, given their increased robustness and innate O2-CO2 exchange. In this study, the interplay between CO2-consuming autotrophy and CO2-producing heterotrophy in a non-axenic phototrophic biofilm was examined. When the biofilm was cultivated under autotrophic conditions (i.e. no organic carbon), it grew autotrophically and exhibited CO2 uptake. After amending its growth medium with organic carbon (0.25 g/L glucose and 0.28 g/L sodium acetate), the biofilm rapidly toggled from net-autotrophic to net-heterotrophic growth, reaching a CO2 production rate of 60 μmol/h after 31 hours. When the organic carbon sources were provided at a lower concentration (0.125 g/L glucose and 0.14 g/L sodium acetate), the biofilm exhibited distinct, longitudinally discrete regions of heterotrophic and autotrophic metabolism in the proximal and distal halves of the biofilm respectively, within 4 hours of carbon amendment. Interestingly, this upstream and downstream partitioning of heterotrophic and autotrophic metabolism appeared to be reversible, as the position of these regions began to flip once the direction of medium flow (and hence nutrient availability) was reversed. The insight generated here can inform new and important research questions and contribute to efforts aimed at scaling and industrializing algal growth systems, where the ability to understand, predict, and optimize biofilm growth and activity is critical.

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Terry, Kenneth L., and Lawrence P. Raymond. "System design for the autotrophic production of microalgae." Enzyme and Microbial Technology 7, no. 10 (October 1985): 474–87. http://dx.doi.org/10.1016/0141-0229(85)90148-6.

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12

Drosg, B. "Photo-autotrophic Production of Poly(hydroxyalkanoates) in Cyanobacteria." Chemical and Biochemical Engineering Quarterly 29, no. 2 (July 12, 2015): 145–56. http://dx.doi.org/10.15255/cabeq.2014.2254.

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13

Dexter, J., P. Armshaw, C. Sheahan, and J. T. Pembroke. "The state of autotrophic ethanol production in Cyanobacteria." Journal of Applied Microbiology 119, no. 1 (May 19, 2015): 11–24. http://dx.doi.org/10.1111/jam.12821.

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14

Oh, S. E., M. S. Bum, Y. B. Yoo, A. Zubair, and I. S. Kim. "Nitrate removal by simultaneous sulfur utilizing autotrophic and heterotrophic denitrification under different organics and alkalinity conditions: batch experiments." Water Science and Technology 47, no. 1 (January 1, 2003): 237–44. http://dx.doi.org/10.2166/wst.2003.0061.

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The effect of various organic compounds were tested using lab-scale batch reactors. At sufficient alkalinity, the initial nitrate nitrogen concentration of 100 mg/L was completely reduced in all batch reactors. Sulfate production decreased by the addition of organics. The concentration range of organics used in this experiment did not inhibit autotrophic denitrification except for propionate. Propionate inhibited autotrophic denitrification a little, indicated by a lower sulfate production rate. Biomass in suspension increased with higher initial organic concentrations, showing higher DOC consumption. As the concentration of organics increased, alkalinity increased accordingly. Under the conditions of low alkalinity, in the case of a control reactor without organics, only about 30% of the initial nitrate was reduced. With half the theoretically required dosage of methanol, the denitrification rates increased slightly. When ethanol, acetate, and propionate were used, denitrification went to completion. When excess organics was added, however, sulfate production was significantly decreased. Interestingly, even when small amounts of organics were added, autotrophic denitrification was promoted as indicated by the sulfate production.

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15

Benemann, John R., Ian Woertz, and Tryg Lundquist. "Autotrophic Microalgae Biomass Production: From Niche Markets to Commodities." Industrial Biotechnology 14, no. 1 (February 2018): 3–10. http://dx.doi.org/10.1089/ind.2018.29118.jrb.

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16

Davis, Ryan, Andy Aden, and Philip T. Pienkos. "Techno-economic analysis of autotrophic microalgae for fuel production." Applied Energy 88, no. 10 (October 2011): 3524–31. http://dx.doi.org/10.1016/j.apenergy.2011.04.018.

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17

Liu, Hengyuan, and Chenhe Zhang. "Effect of current on biofilm-electrode reactor coupled with sulfur autotrophic denitrification process (BER-SAD) for nitrate removal from wastewater." E3S Web of Conferences 267 (2021): 02021. http://dx.doi.org/10.1051/e3sconf/202126702021.

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The biofilm-electrode reactor coupled with sulfur autotrophic denitrification process (BER-SAD) was used to remove nitrate in groundwater, and the effect of current intensity on the denitrification characteristics of the coupled process was explored. Current intensity had a great influence on the denitrification effect of the coupled process, the maximum nitrate removal efficiency of 99.9% and lowest nitrite production were gained under the optimum current density of 100 mA. Moreover, the accumulation concentration of SO42- increased gradually with the increase of current intensity. With the increase of current intensity, the proportion of hydrogen autotrophic denitrification decreased, while the proportion of sulfur autotrophic denitrification increased.

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18

Bardgett, Richard D., Andreas Richter, Roland Bol, Mark H. Garnett, Rupert Bäumler, Xingliang Xu, Elisa Lopez-Capel, et al. "Heterotrophic microbial communities use ancient carbon following glacial retreat." Biology Letters 3, no. 5 (July 3, 2007): 487–90. http://dx.doi.org/10.1098/rsbl.2007.0242.

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When glaciers retreat they expose barren substrates that become colonized by organisms, beginning the process of primary succession. Recent studies reveal that heterotrophic microbial communities occur in newly exposed glacial substrates before autotrophic succession begins. This raises questions about how heterotrophic microbial communities function in the absence of carbon inputs from autotrophs. We measured patterns of soil organic matter development and changes in microbial community composition and carbon use along a 150-year chronosequence of a retreating glacier in the Austrian Alps. We found that soil microbial communities of recently deglaciated terrain differed markedly from those of later successional stages, being of lower biomass and higher abundance of bacteria relative to fungi. Moreover, we found that these initial microbial communities used ancient and recalcitrant carbon as an energy source, along with modern carbon. Only after more than 50 years of organic matter accumulation did the soil microbial community change to one supported primarily by modern carbon, most likely from recent plant production. Our findings suggest the existence of an initial stage of heterotrophic microbial community development that precedes autotrophic community assembly and is sustained, in part, by ancient carbon.

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Hatziconstantinou, G. J., and A. Andreadakis. "Differences in nitrification potential between fully aerobic and nitrogen removal activated sludge systems." Water Science and Technology 46, no. 1-2 (July 1, 2002): 297–304. http://dx.doi.org/10.2166/wst.2002.0492.

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Experimental observations made on two pilot plants, showed that nitrogen removal activated sludge systems, operating under favourable conditions, seem to develop increased nitrification potential compared to fully aerobic systems under similar conditions. This increased potential, which cannot be detected by simple nitrification performance evaluations, is attributed to higher autotrophic populations sustained – developed in similar systems employing anoxic reactors or phases. A reduced autotrophic decay rate under anoxic conditions as reported by some researchers, seems to play a significant role in such a response, most likely together with a more efficient use of available nitrogen for additional nitrifying microorganisms production, resulting from a reduced nitrogen loss to autotrophic biomass maintenance needs and heterotrophic biomass synthesis requirements.

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Nugroho, R., H. Takanashi, M. Hirata, and T. Hano. "Denitrification of industrial wastewater with sulfur and limestone packed column." Water Science and Technology 46, no. 11-12 (December 1, 2002): 99–104. http://dx.doi.org/10.2166/wst.2002.0723.

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An autotrophic denitrification system was developed for nitrate contaminated industrial wastewater whose C/N ratio was very low. The microbes containing Thiobacillus denitrificans as a dominant species were attached on the surface of granular elemental sulfur packed in a column. Elemental sulfur was used as an electron donor for autotrophic denitrification. The granules of limestone were mixed with the granular sulfur to moderate the decrease of alkalinity during autotrophic denitrification. The stoichiometry and basic kinetics of denitrification were studied in column runs. The effects of minerals such as phosphorus on treatment performance were clarified. The wastewater from steel production plants was treated by the present biofilm process. Low extent of nitrogen removal was caused by the lack of minerals.

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Gao, Yu Qiang, Qiu Yan Zhang, Li Huang, Lin Wang, and Xu Ya Yu. "The Influence of Various pH Values on Monoraphidium sp. FXY-10 Growth and Lipid Parameters in Autotrophic and Heterotrophic Conditions." Advanced Materials Research 864-867 (December 2013): 60–66. http://dx.doi.org/10.4028/www.scientific.net/amr.864-867.60.

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The influence of pH on Monoraphidium sp. FXY-10 growth, lipid content, lipid yield, biomass yield, and fatty acid composition is studied in autotrophic and heterotrophic conditions. The results reveal that Monoraphidium sp. FXY-10 can grow better in an acidic environment. Under autotrophic and heterotrophic conditions, the culture time is 37 and 9 day, respectively. And the maximum biomass of algal cells is 32 and 367mg/l/d with the lipid content in autotrophic and heterotrophic conditions reached to 49% and 39%, respectively, with high biomass yield, lipid yield, the saturated fatty acid and monounsaturated fatty acid under heterotrophic condition, proving that the algal cells are a viable material for the production of biodiesel.

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Shen, Xiao-Fei, Hao Hu, Lin-Lin Ma, Paul K. S. Lam, Shao-Kai Yan, Shou-Biao Zhou, and Raymond Jianxiong Zeng. "FAMEs production from Scenedesmus obliquus in autotrophic, heterotrophic and mixotrophic cultures under different nitrogen conditions." Environmental Science: Water Research & Technology 4, no. 3 (2018): 461–68. http://dx.doi.org/10.1039/c7ew00470b.

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Lackner, Nina, Anna Hintersonnleitner, Andreas Otto Wagner, and Paul Illmer. "Hydrogenotrophic Methanogenesis and Autotrophic Growth ofMethanosarcina thermophila." Archaea 2018 (July 17, 2018): 1–7. http://dx.doi.org/10.1155/2018/4712608.

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Although Methanosarcinales are versatile concerning their methanogenic substrates, the ability ofMethanosarcina thermophilato use carbon dioxide (CO2) for catabolic and anabolic metabolism was not proven until now. Here, we show thatM. thermophilaused CO2to perform hydrogenotrophic methanogenesis in the presence as well as in the absence of methanol. During incubation with hydrogen, the methanogen utilized the substrates methanol and CO2consecutively, resulting in a biphasic methane production. Growth exclusively from CO2occurred slowly but reproducibly with concomitant production of biomass, verified by DNA quantification. Besides verification through multiple transfers into fresh medium, the identity of the culture was confirmed by 16s RNA sequencing, and the incorporation of carbon atoms from13CO2into13CH4molecules was measured to validate the obtained data. New insights into the physiology ofM. thermophilacan serve as reference for genomic analyses to link genes with metabolic features in uncultured organisms.

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Agusti, Susana, Lorena Vigoya, and Carlos Manuel Duarte. "Annual plankton community metabolism in estuarine and coastal waters in Perth (Western Australia)." PeerJ 6 (June 26, 2018): e5081. http://dx.doi.org/10.7717/peerj.5081.

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The planktonic metabolic balance that is the balance between gross primary production (GPP) and community respiration (CR) was determined in Matilda Bay (estuarine) and Woodman Point (coastal) in Perth, Western Australia. The rates of net community production (NCP = GPP – CR) and the ratio between GPP and CR (P/R) were assessed to evaluate whether the metabolic balance in the two coastal locations tends to be net autotrophic (production exceeding community respiration) or net heterotrophic (respiration exceeding production). We also analyzed environmental variability by measuring temperature, salinity, and nutrients and chlorophyll a concentration. Samples were collected biweekly from March 2014 to March 2015. During the study period the metabolic rates were three times higher in Matilda Bay than in Woodman Point. The predominant metabolism was net autotrophic at both sites with P/R ratios >1 in the majority of the sampling dates. In Matilda Bay, the metabolic rates were negatively correlated with salinity denoting river dynamics influence, and positively with chlorophyll a. In Woodman Point only the GPP was positively correlated with chlorophyll a. The positive correlation between P/R ratio and GPP in Matilda Bay and the positive correlations between the metabolic rates and chlorophyll a suggest that factors controlling autotrophic processes are modulating the planktonic metabolic balance in the coastal marine ecosystem in Perth. Significant correlations were found between CR and GPP-standardized to chlorophyll a and water temperature. The net autotrophic metabolic balance indicates that in both ecosystems planktonic communities are acting as a sink of CO2 and as a source of organic matter and oxygen to the system and are able to export organic matter to other ecosystems.

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Znachor, Petr, and Jiří Nedoma. "Cell specific primary production of autotrophic and mixotrophic phytoplankton in acidified lakes of the Bohemian Forest." Algological Studies/Archiv für Hydrobiologie, Supplement Volumes 112 (May 1, 2004): 141–55. http://dx.doi.org/10.1127/1864-1318/2004/0112-0141.

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Colliver, B. B., and T. Stephenson. "Production of nitrogen oxide and dinitrogen oxide by autotrophic nitrifiers." Biotechnology Advances 18, no. 3 (May 2000): 219–32. http://dx.doi.org/10.1016/s0734-9750(00)00035-5.

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Kitadai, Norio, Ryuhei Nakamura, Masahiro Yamamoto, Ken Takai, Yamei Li, Akira Yamaguchi, Alexis Gilbert, Yuichiro Ueno, Naohiro Yoshida, and Yoshi Oono. "Geoelectrochemical CO production: Implications for the autotrophic origin of life." Science Advances 4, no. 4 (April 2018): eaao7265. http://dx.doi.org/10.1126/sciadv.aao7265.

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Krieg, Thomas, Anne Sydow, Sonja Faust, Ina Huth, and Dirk Holtmann. "CO2to Terpenes: Autotrophic and Electroautotrophic α-Humulene Production withCupriavidus necator." Angewandte Chemie International Edition 57, no. 7 (January 15, 2018): 1879–82. http://dx.doi.org/10.1002/anie.201711302.

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Krieg, Thomas, Anne Sydow, Sonja Faust, Ina Huth, and Dirk Holtmann. "CO2to Terpenes: Autotrophic and Electroautotrophic α-Humulene Production withCupriavidus necator." Angewandte Chemie 130, no. 7 (January 15, 2018): 1897–900. http://dx.doi.org/10.1002/ange.201711302.

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Duangjan, Kritsana, Watsamon Nakkhunthod, Jeeraporn Pekkoh, and Chayakorn Pumas. "Comparison of hydrogen production in microalgae under autotrophic and mixotrophic media." Botanica Lithuanica 23, no. 2 (December 1, 2017): 169–77. http://dx.doi.org/10.1515/botlit-2017-0018.

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AbstractHydrogen is an alternative source of energy of considerable interest, because it is environmentally friendly. Biological hydrogen production processes involving green microalgae are of significant interest. However, until present only few microalgae genera have been studied and almost all of those studies have focused only on cultivation using mixotrophic or heterotrophic media, which are expensive, and can be easily contaminated. This study aimed to compare the potential of biohydrogen production from novel green microalgae under autotrophic and mixotrophic media. A total of ninety strains of six orders of green microalgae were investigated for their capabilities of hydrogen production. The results showed that eleven novel hydrogen-producing microalgae genera were found. The hydrogen production in each order was influenced by the medium. Moreover, several strains presented notable levels of autotrophic hydrogen production and performed at over twice of the mixotrophic medium. These results should be supportive information for the selection and cultivation of hydrogen-producing microalgae in further studies.

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Weymann, D., H. Geistlinger, R. Well, C. von der Heide, and H. Flessa. "Kinetics of N<sub>2</sub>O production and reduction in a nitrate-contaminated aquifer inferred from laboratory incubation experiments." Biogeosciences 7, no. 6 (June 20, 2010): 1953–72. http://dx.doi.org/10.5194/bg-7-1953-2010.

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Abstract. Knowledge of the kinetics of N2O production and reduction in groundwater is essential for the assessment of potential indirect emissions of the greenhouse gas. In the present study, we investigated this kinetics using a laboratory approach. The results were compared to field measurements in order to examine their transferability to the in situ conditions. The study site was the unconfined, predominantly sandy Fuhrberger Feld aquifer in northern Germany. A special characteristic of the aquifer is the occurrence of the vertically separated process zones of heterotrophic denitrification in the near-surface groundwater and of autotrophic denitrification in depths beyond 2–3 m below the groundwater table, respectively. The kinetics of N2O production and reduction in both process zones was studied during long-term anaerobic laboratory incubations of aquifer slurries using the 15N tracer technique. We measured N2O, N2, NO3-, NO2-, and SO42- concentrations as well as parameters of the aquifer material that were related to the relevant electron donors, i.e. organic carbon and pyrite. The laboratory incubations showed a low denitrification activity of heterotrophic denitrification with initial rates between 0.2 and 13 μg N kg−1 d−1. The process was carbon limited due to the poor availability of its electron donor. In the autotrophic denitrification zone, initial denitrification rates were considerably higher, ranging between 30 and 148 μg N kg−1 d−1, and NO3- as well as N2O were completely removed within 60 to 198 days. N2O accumulated during heterotrophic and autotrophic denitrification, but maximum concentrations were substantially higher during the autotrophic process. The results revealed a satisfactory transferability of the laboratory incubations to the field scale for autotrophic denitrification, whereas the heterotrophic process less reflected the field conditions due to considerably lower N2O accumulation during laboratory incubation. Finally, we applied a conventional model using first-order-kinetics to determine the reaction rate constants k1 for N2O production and k2 for N2O reduction, respectively. The goodness of fit to the experimental data was partly limited, indicating that a more sophisticated approach is essential to describe the investigated reaction kinetics satisfactorily.

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Li, Chaofeng, Jiyang Zheng, Yushuang Wu, Xiaotong Wang, Hui Shao, and Dong Yan. "Light-Driven Synthetic Biology: Progress in Research and Industrialization of Cyanobacterial Cell Factory." Life 12, no. 10 (October 3, 2022): 1537. http://dx.doi.org/10.3390/life12101537.

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Light-driven synthetic biology refers to an autotrophic microorganisms-based research platform that remodels microbial metabolism through synthetic biology and directly converts light energy into bio-based chemicals. This technology can help achieve the goal of carbon neutrality while promoting green production. Cyanobacteria are photosynthetic microorganisms that use light and CO2 for growth and production. They thus possess unique advantages as “autotrophic cell factories”. Various fuels and chemicals have been synthesized by cyanobacteria, indicating their important roles in research and industrial application. This review summarized the progresses and remaining challenges in light-driven cyanobacterial cell factory. The choice of chassis cells, strategies used in metabolic engineering, and the methods for high-value CO2 utilization will be discussed.

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Ni, Bing-Jie, Lai Peng, Yingyu Law, Jianhua Guo, and Zhiguo Yuan. "Modeling of Nitrous Oxide Production by Autotrophic Ammonia-Oxidizing Bacteria with Multiple Production Pathways." Environmental Science & Technology 48, no. 7 (March 11, 2014): 3916–24. http://dx.doi.org/10.1021/es405592h.

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Robarts, Richard D., and Richard J. Wicks. "Heterotrophic Bacterial Production and Its Dependence on Autotrophic Production in a Hypertrophic African Reservoir." Canadian Journal of Fisheries and Aquatic Sciences 47, no. 5 (May 1, 1990): 1027–37. http://dx.doi.org/10.1139/f90-117.

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The incorporation of [methyl-3H]thymidine (TdR) into bacterial DNA in Hartbeespoort Dam, South Africa was measured over 16 mo and at nine depths. Bacterial numbers at the surface ranged between 2.45 and 32.20 × 106 cells∙mL−1[Formula: see text] while bacterial production varied between 1.0 and 251 pmol TdR∙L−1∙h−1 (0.01 to 1.9 mg C∙m−3∙h−1). At the bottom, production ranged between 0 and 26.7 pmol TdR∙L−1∙h−1 (0–0.2 mg C∙m−3∙h−1). The fastest bacterial doubling time was 59 h. At the surface, bacterial production was dominantly correlated to chlorophyll a (6.6–6530 mg∙m−3) and phaeopigments (0.9–378 mg∙m−3) (r = 0.81) followed by primary production (26.6–8886 mg C∙m−3∙h−1) (r = 0.77) (n = 30–34, p < 0.001). However, below 5 m, water temperature and bacterial numbers were the dominant correlates. Bacterial production for the water column averaged 2% of daily, areal primary production. The data demonstrated a close coupling between autotrophic production and heterotrophic bacterial production. However, the low bacterial production compared with primary production, together with the small size of the bacteria (usually 0.09–0.25 μm width), suggest substrate supply was a major limiting factor of bacterial growth.

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Devresse, Quentin, Kevin W. Becker, Arne Bendinger, Johannes Hahn, and Anja Engel. "Eddy-enhanced primary production sustains heterotrophic microbial activities in the Eastern Tropical North Atlantic." Biogeosciences 19, no. 22 (November 17, 2022): 5199–219. http://dx.doi.org/10.5194/bg-19-5199-2022.

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Abstract. Mesoscale eddies modulate the ocean's physical, chemical, and biological properties. In cyclonic eddies (CEs), nutrient upwelling can stimulate primary production by phytoplankton. Yet, how this locally enhanced autotrophic production affects heterotrophy and consequently the metabolic balance between the synthesis and the consumption of dissolved organic matter (DOM) remains largely unknown. To fill this gap, we investigated the horizontal and vertical variability in auto- and heterotrophic microbial activity (biomass production and respiration) within a CE that formed off Mauritania and along the ∼ 900 km zonal corridor between Mauritania and the Cape Verde islands in the Eastern Tropical North Atlantic (ETNA). Our results show how the physical disturbances caused by the CE affected the biomass distribution of phyto- and bacterioplankton and their metabolic activities. The injection of nutrients into the sunlit surface resulted in enhanced autotrophic pico- and nanoplankton abundance and generally increased autotrophic activity as indicated by chlorophyll a (Chl a) concentration, primary production (PP), and extracellular release rates. However, the detailed eddy survey also revealed an uneven distribution of these variables with, for example, the highest Chl a concentrations and PP rates occurring near and just beyond the CE's periphery. The heterotrophic bacterial activity was similarly variable. Optode-based community respiration (CR), bacterial respiration (BR) estimates, and bacterial biomass production (BP) largely followed the trends of PP and Chl a. Thus, a submesoscale spatial mosaic of heterotrophic bacterial abundance and activities occurred within the CE that was closely related to variability in autotrophic production. Consistent with this, we found a significant positive correlation between concentrations of semi-labile dissolved organic carbon (SL-DOC; here the sum of dissolved hydrolysable amino acids and dissolved combined carbohydrates) and BR estimates. Extracellular release of carbon as indicated by primary production of dissolved organic carbon (PPDOC) was variable with depth and laterally and not always sufficient to compensate the bacterial carbon demand (BCD: BR + BP), with PPDOC accounting for between 28 % and 110 % of the BCD. Bacterial growth efficiency (BGE: BP / BCD) ranged between 1.7 % and 18.2 %. We estimated the metabolic state to establish whether the CE was a source or a sink of organic carbon. We showed that the CE carried a strong autotrophic signal in the core (PP / CR > 1). Our results suggest that submesoscale (0–10 km) processes lead to highly variable metabolic activities in both photoautotrophic and heterotrophic microorganisms. Overall, we revealed that the CEs not only trap and transport coastal nutrients and organic carbon to the open ocean but also stimulate phytoplankton growth, generating freshly produced organic matter during westward propagation. This drives heterotrophic processes and may contribute to the previously observed net heterotrophy in open Atlantic surface waters.

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Koeve, W., and P. Kähler. "Heterotrophic denitrification vs. autotrophic anammox – quantifying collateral effects on the oceanic carbon cycle." Biogeosciences Discussions 7, no. 2 (March 16, 2010): 1813–37. http://dx.doi.org/10.5194/bgd-7-1813-2010.

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Abstract. The conversion of fixed nitrogen to N2 in suboxic waters is estimated to contribute roughly a third to total oceanic losses of fixed nitrogen and is hence understood to be of major importance to global oceanic production and, therefore, to the role of the ocean as a sink of atmospheric CO2. At present heterotrophic denitrification and autotrophic anammox are considered the dominant sinks of fixed nitrogen. Recently, it has been suggested that the trophic nature of pelagic N2-production may have additional, "collateral" effects on the carbon cycle, where heterotrophic denitrification provides a shallow source of CO2 and autotrophic anammox a shallow sink. Here, we analyse the stoichiometries of nitrogen and associated carbon conversions in marine oxygen minimum zones (OMZ) focusing on heterotrophic denitrification, autotrophic anammox, and dissimilatory nitrate reduction to nitrite and ammonium in order to test this hypothesis quantitatively. For open ocean OMZs the combined effects of these processes turn out to be clearly heterotrophic, even with high shares of the autotrophic anammox reaction in total N2-production and including various combinations of dissimilatory processes which provide the substrates to anammox. In such systems, the degree of heterotrophy (ΔCO2:ΔN2), varying between 1.7 and 6, is a function of the efficiency of nitrogen conversion. On the contrary, in systems like the Black Sea, where suboxic N-conversions are supported by diffusive fluxes of NH4+ originating from neighbouring waters with sulphate reduction, much lower values of ΔCO2:ΔN2 can be found. However, accounting for concomitant diffusive fluxes of CO2, ratios approach higher values similar to those computed for open ocean OMZs. Based on our analysis, we question the significance of collateral effects concerning the trophic nature of suboxic N-conversions on the marine carbon cycle.

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Koeve, W., and P. Kähler. "Heterotrophic denitrification vs. autotrophic anammox – quantifying collateral effects on the oceanic carbon cycle." Biogeosciences 7, no. 8 (August 6, 2010): 2327–37. http://dx.doi.org/10.5194/bg-7-2327-2010.

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Abstract. The conversion of fixed nitrogen to N2 in suboxic waters is estimated to contribute roughly a third to total oceanic losses of fixed nitrogen and is hence understood to be of major importance to global oceanic production and, therefore, to the role of the ocean as a sink of atmospheric CO2. At present heterotrophic denitrification and autotrophic anammox are considered the dominant sinks of fixed nitrogen. Recently, it has been suggested that the trophic nature of pelagic N2-production may have additional, "collateral" effects on the carbon cycle, where heterotrophic denitrification provides a shallow source of CO2 and autotrophic anammox a shallow sink. Here, we analyse the stoichiometries of nitrogen and associated carbon conversions in marine oxygen minimum zones (OMZ) focusing on heterotrophic denitrification, autotrophic anammox, and dissimilatory nitrate reduction to nitrite and ammonium in order to test this hypothesis quantitatively. For open ocean OMZs the combined effects of these processes turn out to be clearly heterotrophic, even with high shares of the autotrophic anammox reaction in total N2-production and including various combinations of dissimilatory processes which provide the substrates to anammox. In such systems, the degree of heterotrophy (ΔCO2:ΔN2), varying between 1.7 and 6.5, is a function of the efficiency of nitrogen conversion. On the contrary, in systems like the Black Sea, where suboxic N-conversions are supported by diffusive fluxes of NH4+ originating from neighbouring waters with sulphate reduction, much lower values of ΔCO2:ΔN2 can be found. However, accounting for concomitant diffusive fluxes of CO2, the ratio approaches higher values similar to those computed for open ocean OMZs. Based on this analysis, we question the significance of collateral effects concerning the trophic nature of suboxic N-conversions on the marine carbon cycle.

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Fouchard, Swanny, Anja Hemschemeier, Amandine Caruana, Jérémy Pruvost, Jack Legrand, Thomas Happe, Gilles Peltier, and Laurent Cournac. "Autotrophic and Mixotrophic Hydrogen Photoproduction in Sulfur-Deprived Chlamydomonas Cells." Applied and Environmental Microbiology 71, no. 10 (October 2005): 6199–205. http://dx.doi.org/10.1128/aem.71.10.6199-6205.2005.

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ABSTRACT In Chlamydomonas reinhardtii cells, H2 photoproduction can be induced in conditions of sulfur deprivation in the presence of acetate. The decrease in photosystem II (PSII) activity induced by sulfur deprivation leads to anoxia, respiration becoming higher than photosynthesis, thereby allowing H2 production. Two different electron transfer pathways, one PSII dependent and the other PSII independent, have been proposed to account for H2 photoproduction. In this study, we investigated the contribution of both pathways as well as the acetate requirement for H2 production in conditions of sulfur deficiency. By using 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), a PSII inhibitor, which was added at different times after the beginning of sulfur deprivation, we show that PSII-independent H2 photoproduction depends on previously accumulated starch resulting from previous photosynthetic activity. Starch accumulation was observed in response to sulfur deprivation in mixotrophic conditions (presence of acetate) but also in photoautotrophic conditions. However, no H2 production was measured in photoautotrophy if PSII was not inhibited by DCMU, due to the fact that anoxia was not reached. When DCMU was added at optimal starch accumulation, significant H2 production was measured. H2 production was enhanced in autotrophic conditions by removing O2 using N2 bubbling, thereby showing that substantial H2 production can be achieved in the absence of acetate by using the PSII-independent pathway. Based on these data, we discuss the possibilities of designing autotrophic protocols for algal H2 photoproduction.

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Najdek, M., P. Paliaga, T. Šilović, M. Batistić, R. Garić, N. Supić, I. Ivančić, et al. "Picoplankton community structure before, during and after convection event in the offshore waters of the southern Adriatic Sea." Biogeosciences Discussions 10, no. 11 (November 15, 2013): 17859–92. http://dx.doi.org/10.5194/bgd-10-17859-2013.

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Abstract. This paper documents the picoplankton community's response to changes in oceanographic conditions in the period between October 2011 and September 2012 at two stations belonging to South Adriatic Pit (SAP). The recorded data include the community's abundance, composition, prokaryotic production rates and bacterial metabolic capacity. The aforementioned interval included an intense sea cooling with formation of exceptionally, record-breaking dense water. We documented an especially intense winter convection episode that completely diluted the core of Levantine intermediate waters (LIW) in a large area encompassing the SAP's center and its margin. During this convection event the whole picoplankton community had significantly higher abundances with a recorded picoeukaryotic peak at the SAP margin. In the post-convection phase in March prokaryotic heterotrophic production strongly increased in the entire SAP area (up to 50 times; 456.8 nM C day−1). The autotrophic biomass increase (up to 5 times; 4.86 μg L−1) and a disruption of a close correspondence between prokaryotic heterotrophic biomass production and cell replication rates were observed only in the center of the SAP, which was not under the influence of LIW. At the SAP's margin such an effect was attenuated by LIW, since the waters affected by LIW were characterized by decreased concentrations of dissolved inorganic nitrogen, decreased autotrophic biomasses and by increased bacterial biomass production balanced with cell replication rates as well as by the domination of Synechococcus among autotrophic picoplankton. Metabolic capacity was the lowest in spring when autotrophic biomass largely increased, while the highest levels found in the pre-convection phase (October 2011) suggests that the system was more oligotrophic before than after the convection event. Furthermore, we showed that metabolic capacity is a trait of bacterial community independent of environmental conditions and tightly linked to cell replication and substrate availability. On the other hand the bacterial community composition appears to be strongly influenced by physico-chemical characteristics of waters (e.g. temperature and nutrients) and environmental forcing (e.g. convection and LIW).

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40

Mook, Alexander, Matthias H. Beck, Jonathan P. Baker, Nigel P. Minton, Peter Dürre, and Frank R. Bengelsdorf. "Autotrophic lactate production from H2 + CO2 using recombinant and fluorescent FAST-tagged Acetobacterium woodii strains." Applied Microbiology and Biotechnology 106, no. 4 (January 29, 2022): 1447–58. http://dx.doi.org/10.1007/s00253-022-11770-z.

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AbstractLactate has various uses as industrial platform chemical, poly-lactic acid precursor or feedstock for anaerobic co-cultivations. The aim of this study was to construct and characterise Acetobacterium woodii strains capable of autotrophic lactate production. Therefore, the lctBCD genes, encoding the native Lct dehydrogenase complex, responsible for lactate consumption, were knocked out. Subsequently, a gene encoding a d-lactate dehydrogenase (LDHD) originating from Leuconostoc mesenteroides was expressed in A. woodii, either under the control of the anhydrotetracycline-inducible promoter Ptet or under the lactose-inducible promoter PbgaL. Moreover, LDHD was N-terminally fused to the oxygen-independent fluorescence-activating and absorption-shifting tag (FAST) and expressed in respective A. woodii strains. Cells that produced the LDHD fusion protein were capable of lactate production of up to 18.8 mM in autotrophic batch experiments using H2 + CO2 as energy and carbon source. Furthermore, cells showed a clear and bright fluorescence during exponential growth, as well as in the stationary phase after induction, mediated by the N-terminal FAST. Flow cytometry at the single-cell level revealed phenotypic heterogeneities for cells expressing the FAST-tagged LDHD fusion protein. This study shows that FAST provides a new reporter tool to quickly analyze gene expression over the course of growth experiments of A. woodii. Consequently, fluorescence-based reporters allow for faster and more targeted optimization of production strains.Key points •Autotrophic lactate production was achieved with A. woodii. •FAST functions as fluorescent marker protein in A. woodii. •Fluorescence measurements on single-cell level revealed population heterogeneity.

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41

Najdek, M., P. Paliaga, T. Šilović, M. Batistić, R. Garić, N. Supić, I. Ivančić, et al. "Picoplankton community structure before, during and after convection event in the offshore waters of the Southern Adriatic Sea." Biogeosciences 11, no. 10 (May 20, 2014): 2645–59. http://dx.doi.org/10.5194/bg-11-2645-2014.

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Abstract. This paper documents the picoplankton community's response to changes in oceanographic conditions in the period between October 2011 and September 2012 at two stations belonging to the South Adriatic Pit (SAP). The recorded data include the community's abundance, composition, prokaryotic production rates and bacterial metabolic capacity. The sampling period included an intense sea cooling with formation of exceptional, record-breaking dense water. We documented an especially intense winter convection episode that completely diluted the core of Levantine intermediate waters (LIW) in a large area encompassing the SAP's center and its margin. During this convection event the whole picoplankton community had significantly higher abundances with a recorded picoeukaryotic peak at the SAP margin. In the post-convection phase in March, prokaryotic heterotrophic production strongly increased in the entire SAP area (up to 50 times; 456.8 nM C day−1). An autotrophic biomass increase (up to 5 times; 4.86 μg L−1) and a disruption of a close correspondence between prokaryotic heterotrophic biomass production and cell replication rates were observed only in the center of the SAP, which was not under the influence of LIW. At the SAP's margin such an effect was attenuated by LIW, since the waters affected by LIW were characterized by decreased concentrations of dissolved inorganic nitrogen, decreased autotrophic biomasses, and by increased bacterial biomass production balanced with cell replication rates as well as by the domination of Synechococcus among autotrophic picoplankton. The metabolic capacity was lowest in spring when autotrophic biomass largely increased, while the highest levels found in the pre-convection phase (October 2011) suggest that the system was more oligotrophic before than after the convection event. Furthermore, we showed that metabolic capacity is a trait of bacterial community independent of environmental conditions and tightly linked to cell replication and substrate availability. In contrast, the bacterial community composition appears to be strongly influenced by physico-chemical characteristics of waters (e.g., temperature and nutrients) and environmental forcing (e.g., convection and LIW). Our results showed that the two oceanographic phenomena of the Southern Adriatic, strongly relevant for the total production of the Adriatic Sea, winter convection and LIW intrusion, regulate the changes in picoplankton community structure and activities.

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42

Varman, Arul M., Yi Xiao, Himadri B. Pakrasi, and Yinjie J. Tang. "Metabolic Engineering of Synechocystis sp. Strain PCC 6803 for Isobutanol Production." Applied and Environmental Microbiology 79, no. 3 (November 26, 2012): 908–14. http://dx.doi.org/10.1128/aem.02827-12.

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ABSTRACTGlobal warming and decreasing fossil fuel reserves have prompted great interest in the synthesis of advanced biofuels from renewable resources. In an effort to address these concerns, we performed metabolic engineering of the cyanobacteriumSynechocystissp. strain PCC 6803 to develop a strain that can synthesize isobutanol under both autotrophic and mixotrophic conditions. With the expression of two heterologous genes from the Ehrlich pathway, the engineered strain can accumulate 90 mg/liter of isobutanol from 50 mM bicarbonate in a gas-tight shaking flask. The strain does not require any inducer (i.e., isopropyl β-d-1-thiogalactopyranoside [IPTG]) or antibiotics to maintain its isobutanol production. In the presence of glucose, isobutanol synthesis is only moderately promoted (titer = 114 mg/liter). Based on isotopomer analysis, we found that, compared to the wild-type strain, the mutant significantly reduced its glucose utilization and mainly employed autotrophic metabolism for biomass growth and isobutanol production. Since isobutanol is toxic to the cells and may also be degraded photochemically by hydroxyl radicals during the cultivation process, we employedin situremoval of the isobutanol using oleyl alcohol as a solvent trap. This resulted in a final net concentration of 298 mg/liter of isobutanol under mixotrophic culture conditions.

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Chavoshi, Zohreh Zare, and Mansour Shariati. "Lipid production in Dunaliella salina under autotrophic, heterotrophic, and mixotrophic conditions." Biologia 74, no. 12 (August 16, 2019): 1579–90. http://dx.doi.org/10.2478/s11756-019-00336-6.

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Zeng, Xianhai, Michael K. Danquah, Shiduo Zhang, Xia Zhang, Mengyang Wu, Xiao Dong Chen, I.-Son Ng, Keju Jing, and Yinghua Lu. "Autotrophic cultivation of Spirulina platensis for CO2 fixation and phycocyanin production." Chemical Engineering Journal 183 (February 2012): 192–97. http://dx.doi.org/10.1016/j.cej.2011.12.062.

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Parsons, T. R., D. G. Webb, B. E. Rokeby, M. Lawrence, G. E. Hopky, and D. B. Chiperzak. "Autotrophic and heterotrophic production in the Mackenzie river/Beaufort Sea estuary." Polar Biology 9, no. 4 (March 1989): 261–66. http://dx.doi.org/10.1007/bf00263774.

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Zinn, M., V. Amstutz, N. Hanik, J. Pott, and C. Utsunomia. "Grave-to-cradle: The potential of autotrophic bioprocesses in bioplastic production." New Biotechnology 44 (October 2018): S64. http://dx.doi.org/10.1016/j.nbt.2018.05.1209.

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Straub, Melanie, Martin Demler, Dirk Weuster-Botz, and Peter Dürre. "Selective enhancement of autotrophic acetate production with genetically modified Acetobacterium woodii." Journal of Biotechnology 178 (May 2014): 67–72. http://dx.doi.org/10.1016/j.jbiotec.2014.03.005.

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48

Sublette, Kerry L. "Production of microbial biomass protein from autotrophic fermentation of hydrogen sulfide." Biotechnology and Bioengineering 32, no. 3 (July 20, 1988): 408–9. http://dx.doi.org/10.1002/bit.260320324.

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Weymann, D., H. Geistlinger, R. Well, C. von der Heide, and H. Flessa. "Kinetics of N<sub>2</sub>O production and reduction in a nitrate-contaminated aquifer inferred from laboratory incubation experiments." Biogeosciences Discussions 7, no. 1 (January 20, 2010): 503–43. http://dx.doi.org/10.5194/bgd-7-503-2010.

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Abstract. Knowledge of the kinetics of N2O production and reduction in groundwater is essential for the assessment of potential indirect emissions of the greenhouse gas. In this study, we investigated this kinetics using a laboratory approach. The results were compared to field measurements in order to examine their transferability to the in situ conditions. The study site was the unconfined, predominantly sandy Fuhrberger Feld aquifer in Northern Germany. A special characteristic of the aquifer is the occurrence of the vertically separated process zones of heterotrophic denitrification in the surface groundwater and of autotrophic denitrification in the deeper groundwater, respectively. The kinetics of N2O production and reduction in both process zones was studied during long-term anaerobic laboratory incubations of aquifer slurries using the 15N tracer technique. We measured N2O, N2 and NO3− concentrations as well as parameters of the aquifer material that were related to the relevant electron donors, i.e. organic carbon and sulfur. The anaerobic incubations showed a low denitrification activity of heterotrophic denitrification with initial rates between 0.0002 and 0.0133 mg N kg−1 day−1. The process was carbon limited due to the poor availability of its electron donor. In the autotrophic denitrification zone, initial denitrification rates were considerably higher, ranging between 0.0303 and 0.1480 mg N kg−1 d−1 and NO3− as well as N2O were completely removed within 60 to 198 days. N2O accumulated during heterotrophic and autotrophic denitrification, but maximum concentrations were substantially higher during the autotrophic process. The results revealed a satisfactory transferability of the laboratory incubations to the field scale for autotrophic denitrification, whereas the heterotrophic process less reflected the field conditions due to considerably lower N2O accumulation during laboratory incubation. Finally, we applied a conventional model using first-order-kinetics to determine the reaction rates of the NO3−-to-N2O step and the N2O-to-N2 step, and evaluated the reaction rate constants for both steps. The model yielded fits to the experimental data that were of limited goodness, indicating that a more sophisticated approach is essential to describe the investigated reaction kinetics satisfactorily.

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Kim, Bohwa, Ramasamy Praveenkumar, Eunji Choi, Kyubock Lee, Sang Jeon, and You-Kwan Oh. "Prospecting for Oleaginous and Robust Chlorella spp. for Coal-Fired Flue-Gas-Mediated Biodiesel Production." Energies 11, no. 8 (August 3, 2018): 2026. http://dx.doi.org/10.3390/en11082026.

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Prospecting for robust and high-productivity strains is a strategically important step in the microalgal biodiesel process. In this study, 30 local strains of Chlorella were evaluated in photobioreactors for biodiesel production using coal-fired flue-gas. Three strains (M082, M134, and KR-1) were sequentially selected based on cell growth, lipid content, and fatty acid composition under autotrophic and mixotrophic conditions. Under autotrophic conditions, M082 and M134 showed comparable lipid contents (ca. 230 mg FAME [fatty acid methyl esters derived from microalgal lipids]/g cell) and productivities (ca. 40 mg FAME/L·d) versus a reference strain (KR-1) outdoors with actual flue-gas (CO2, 13%). Interestingly, under mixotrophic conditions, M082 demonstrated, along with maximal lipid content (397 mg FAME/g cell), good tolerance to high temperature (40 °C). Furthermore, the fatty acid methyl esters met important international standards under all of the tested culture conditions. Thus, it was concluded that M082 can be a feedstock of choice for coal-fired, flue-gas-mediated biodiesel production.

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Journal articles on the topic 'Autotrophic production'

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