Journal articles on the topic 'Cellulose colonization'
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Cheng, K. J., H. Kudo, S. H. Duncan, A. Mesbah, C. S. Stewart, A. Bernalier, G. Fonty, and J. W. Costerton. "Prevention of fungal colonization and digestion of cellulose by the addition of methylcellulose." Canadian Journal of Microbiology 37, no. 6 (June 1, 1991): 484–87. http://dx.doi.org/10.1139/m91-081.
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When the attachment of cellulolytic rumen fungi to cellulose is blocked by the addition of methylcellulose, cellulose digestion is entirely inhibited. Even after these fungi have colonized and penetrated the cellulosic fibers of filter paper, the addition of methylcellulose effectively halts cellulose digestion. This effect of methylcellulose is accompanied by the complete inhibition of fungal attachment to cellulose fibers; the addition of methylcellulose does not affect the growth of these organisms on soluble substrates. We conclude that fungal cellulose digestion, like bacterial cellulose digestion, requires the spatial juxtaposition of the cellulolytic organism and its insoluble substrate. The simultaneous inhibition of both attachment and digestion by the same inhibitor suggests that these two processes are functionally linked in the fungi. Key words: cellulolysis, anaerobic rumen fungi, attachment inhibition, digestion inhibition.
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Yang, Xuan, Kathleen A. Hill, Ryan S. Austin, and Lining Tian. "Differential Gene Expression of Brachypodium distachyon Roots Colonized by Gluconacetobacter diazotrophicus and the Role of BdCESA8 in the Colonization." Molecular Plant-Microbe Interactions® 34, no. 10 (October 2021): 1143–56. http://dx.doi.org/10.1094/mpmi-06-20-0170-r.
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Alternatives to synthetic nitrogen fertilizer are needed to reduce the costs of crop production and offset environmental damage. Nitrogen-fixing bacterium Gluconacetobacter diazotrophicus has been proposed as a possible biofertilizer for monocot crop production. However, the colonization of G. diazotrophicus in most monocot crops is limited and deep understanding of the response of host plants to G. diazotrophicus colonization is still lacking. In this study, the molecular response of the monocot plant model Brachypodium distachyon was studied during G. diazotrophicus root colonization. The gene expression profiles of B. distachyon root tissues colonized by G. diazotrophicus were generated via next-generation RNA sequencing, and investigated through gene ontology and metabolic pathway analysis. The RNA sequencing results indicated that Brachypodium is actively involved in G. diazotrophicus colonization via cell wall synthesis. Jasmonic acid, ethylene, gibberellin biosynthesis. nitrogen assimilation, and primary and secondary metabolite pathways are also modulated to accommodate and control the extent of G. diazotrophicus colonization. Cellulose synthesis is significantly downregulated during colonization. The loss of function mutant for Brachypodium cellulose synthase 8 (BdCESA8) showed decreased cellulose content in xylem and increased resistance to G. diazotrophicus colonization. This result suggested that the cellulose synthesis of the secondary cell wall is involved in G. diazotrophicus colonization. The results of this study provide insights for future research in regard to gene manipulation for efficient colonization of nitrogen-fixing bacteria in Brachypodium and monocot crops. [Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .
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Matthysse, Ann G., Mazz Marry, Leonard Krall, Mitchell Kaye, Bronwyn E. Ramey, Clay Fuqua, and Alan R. White. "The Effect of Cellulose Overproduction on Binding and Biofilm Formation on Roots by Agrobacterium tumefaciens." Molecular Plant-Microbe Interactions® 18, no. 9 (September 2005): 1002–10. http://dx.doi.org/10.1094/mpmi-18-1002.
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Agrobacterium tumefaciens growing in liquid attaches to the surface of tomato and Arabidopsis thaliana roots, forming a biofilm. The bacteria also colonize roots grown in sterile quartz sand. Attachment, root colonization, and biofilm formation all were markedly reduced in celA and chvB mutants, deficient in production of cellulose and cyclic β-(1,2)-D-glucans, respectively. We have identified two genes (celG and celI) in which mutations result in the overproduction of cellulose as judged by chemical fractionation and methylation analysis. Wild-type and chvB mutant strains carrying a cDNA clone of a cellulose synthase gene from the marine urochordate Ciona savignyi also overproduced cellulose. The overproduction in a wild-type strain resulted in increased biofilm formation on roots, as evaluated by light microscopy, and levels of root colonization intermediate between those of cellulose-minus mutants and the wild type. Overproduction of cellulose by a nonattaching chvB mutant restored biofilm formation and bacterial attachment in microscopic and viable cell count assays and partially restored root colonization. Although attachment to plant surfaces was restored, overproduction of cellulose did not restore virulence in the chvB mutant strain, suggesting that simple bacterial binding to plant surfaces is not sufficient for pathogenesis.
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Popa, Elisabeta Elena, Maria Rapa, Calina Petruta Cornea, Vlad Ioan Popa, Amalia Carmen Mitelut, Ovidiu Popa, Mihaela Geicu Cristea, and Mona Elena Popa. "PHB/cellulose Fibres Composites Colonization and biodegradation behavior." Materiale Plastice 55, no. 1 (March 30, 2018): 48–53. http://dx.doi.org/10.37358/mp.18.1.4962.
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In this study, newly developed polymeric composites based on poly(3-hydroxybutyrate) (PHB), cellulose fibres (CF) and plasticizer (bis[2-(2-butoxyethoxy)ethyl] adipate) (DBEEA) were subjected both to microorganism�s action in controlled conditions, and to soil�s action by sample burial. The weight loss of PHB based composites at 60 days exposure were determined in comparison with neat PHB. The weight variation for PHB based composites buried in a natural soil at 45 days and 90 days was monitored. DSC-differential scanning calorimetry and SEM -scanning electron microscopy analysis were performed on the tested composites after 90 days of soil burial. It was found that the introduction of cellulose fibres into PHB leads to the increase of biodegradability of composites.
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Barak, Jeri D., Courtney E. Jahn, Deanna L. Gibson, and Amy O. Charkowski. "The Role of Cellulose and O-Antigen Capsule in the Colonization of Plants by Salmonella enterica." Molecular Plant-Microbe Interactions® 20, no. 9 (September 2007): 1083–91. http://dx.doi.org/10.1094/mpmi-20-9-1083.
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Numerous salmonellosis outbreaks have been associated with vegetables, in particular sprouted seed. Thin aggregative fimbriae (Tafi), a component of the extracellular matrix responsible for multicellular behavior, are important for Salmonella enterica attachment and colonization of plants. Here, we demonstrate that the other surface polymers composing the extracellular matrix, cellulose, and O-antigen capsule also play a role in colonization of plants. Mutations in bacterial cellulose synthesis (bcsA) and O-antigen capsule assembly and translocation (yihO) reduced the ability to attach to and colonize alfalfa sprouts. A colanic acid mutant was unaffected in plant attachment or colonization. Tafi, cellulose synthesis, and O-antigen capsule, all of which contribute to attachment and colonization of plants, are regulated by AgfD, suggesting that AgfD is a key regulator for survival outside of hosts of Salmonella spp. The cellulose biosynthesis regulator adrA mutant was not affected in the ability to attach to or colonize plants; however, promoter probe assays revealed expression by cells attached to alfalfa sprouts. Furthermore, quantitative reverse-transcriptase polymerase chain reaction revealed differential expression of agfD and adrA between planktonic and plant-attached cells. In addition, there was no correlation among mutants between biofilm formation in culture and attachment to plants. Outside of animal hosts, S. enterica appears to rely on an arsenal of adhesins to persist on plants, which can act as vectors and perpetuate public health concerns.
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Ylimartimo, A., G. Laflamme, M. Simard, and D. Rioux. "Ultrastructure and cytochemistry of early stages of colonization by Gremmeniella abietina in Pinus resinosa seedlings." Canadian Journal of Botany 75, no. 7 (July 1, 1997): 1119–32. http://dx.doi.org/10.1139/b97-123.
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This paper provides details on the infection processes at the ultrastructural level in Pinus resinosa Ait. seedlings during early stages of colonization by Gremmeniella abietina (Lagerb.) Morelot. Different gold-conjugated enzymes and antibodies were used to cytochemically localize cellulose, pectin, fungal laccase, and the pathogen cells in host tissues. Gremmeniella abietina penetrated into the host through stomata of the short shoot bracts and sparsely colonized both intercellular and intracellular areas of the bract tissues. The colonizing hyphae usually had a thick wall surrounded by an extracellular sheath composed of fibrillar material. Microhyphaelike cells were observed as having penetrated host cell walls. The fungal cells (except the extracellular sheath), even when embedded in cellulosic or pectic material of host tissues, did not appear to contain cellulose or pectin. We suggest that G. abietina is able to degrade cellulose and pectin and that phenoloxidases secreted by the pathogen could be involved in host cell wall degradation. The results indicate that the extracellular sheath of G. abietina is implicated in host–pathogen interactions such as attachment of hyphae to the host surface and cell wall degradation during colonization of host tissues. Key words: Gremmeniella, Pinus, infection processes, cell wall degradation, extracellular fungal sheath, gold labelling.
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Laus, M. C., A. A. N. van Brussel, and J. W. Kijne. "Role of Cellulose Fibrils and Exopolysaccharides of Rhizobium leguminosarum in Attachment to and Infection of Vicia sativa Root Hairs." Molecular Plant-Microbe Interactions® 18, no. 6 (June 2005): 533–38. http://dx.doi.org/10.1094/mpmi-18-0533.
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Infection and subsequent nodulation of legume host plants by the root nodule symbiote Rhizobium leguminosarum usually require attachment of the bacteria to root-hair tips. Bacterial cellulose fibrils have been shown to be involved in this attachment process but appeared not to be essential for successful nodulation. Detailed analysis of Vicia sativa root-hair infection by wild-type Rhizobium leguminosarum RBL5523 and its cellulose fibril-deficient celE mutant showed that wild-type bacteria infected elongated growing root hairs, whereas cellulose-deficient bacteria infected young emerging root hairs. Exopolysaccharide-deficient strains that retained the ability to produce cellulose fibrils could also infect elongated root hairs but infection thread colonization was defective. Cellulose-mediated agglutination of these bacteria in the root-hair curl appeared to prevent entry into the induced infection thread. Infection experiments with V. sativa roots and an extracellular polysaccharide (EPS)- and cellulose-deficient double mutant showed that cellulose-mediated agglutination of the EPS-deficient bacteria in the infection thread was now abolished and that infection thread colonization was partially restored. Interestingly, in this case, infection threads were initiated in root hairs that originated from the cortical cell layers of the root and not in epidermal root hairs. Apparently, surface polysaccharides of R. leguminosarum, such as cellulose fibrils, are determining factors for infection of different developmental stages of root hairs.
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Gelhaye, E., A. Gehin, and H. Petitdemange. "Colonization of Crystalline Cellulose by Clostridium cellulolyticum ATCC 35319." Applied and Environmental Microbiology 59, no. 9 (1993): 3154–56. http://dx.doi.org/10.1128/aem.59.9.3154-3156.1993.
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El-Ghaouth, Ahmed, Charles L. Wilson, and Michael Wisniewski. "Ultrastructural and Cytochemical Aspects of the Biological Control of Botrytis cinerea by Candida saitoana in Apple Fruit." Phytopathology® 88, no. 4 (April 1998): 282–91. http://dx.doi.org/10.1094/phyto.1998.88.4.282.
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Biocontrol activity of Candida saitoana and its interaction with Botrytis cinerea in apple wounds were investigated. When cultured together, yeast attached to Botrytis sp. hyphal walls. In wounded apple tissue, C. saitoana restricted the proliferation of B. cinerea, multiplied, and suppressed disease caused by either B. cinerea or Penicillium expansum. In inoculated apple tissue without the yeast, fungal colonization caused an extensive degradation of host walls and altered cellulose labeling patterns. Hyphae in close proximity to the antagonistic yeast exhibited severe cytological injury, such as cell wall swelling and protoplasm degeneration. Colonization of the wound site by C. saitoana did not cause degradation of host cell walls. Host cell walls in close contact with C. saitoana cells and B. cinerea hyphae were well preserved and displayed an intense and regular cellulose labeling pattern. In addition to restricting fungal colonization, C. saitoana induced the formation of structural defense responses in apple tissue. The ability of C. saitoana to prevent the necrotrophic growth of the pathogen and stimulate structural defense responses may be the basis of its biocontrol activity.
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Dumitrache, Alexandru, Gideon Wolfaardt, Grant Allen, Steven N. Liss, and Lee R. Lynd. "Form and Function of Clostridium thermocellum Biofilms." Applied and Environmental Microbiology 79, no. 1 (October 19, 2012): 231–39. http://dx.doi.org/10.1128/aem.02563-12.
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ABSTRACTThe importance of bacterial adherence has been acknowledged in microbial lignocellulose conversion studies; however, few reports have described the function and structure of biofilms supported by cellulosic substrates. We investigated the organization, dynamic formation, and carbon flow associated with biofilms of the obligately anaerobic cellulolytic bacteriumClostridium thermocellum27405. Using noninvasive,in situfluorescence imaging, we showed biofilms capable of near complete substrate conversion with a characteristic monolayered cell structure without an extracellular polymeric matrix typically seen in biofilms. Cell division at the interface and terminal endospores appeared throughout all stages of biofilm growth. Using continuous-flow reactors with a rate of dilution (2 h−1) 12-fold higher than the bacterium's maximum growth rate, we compared biofilm activity under low (44 g/liter) and high (202 g/liter) initial cellulose loading. The average hydrolysis rate was over 3-fold higher in the latter case, while the proportions of oligomeric cellulose hydrolysis products lost from the biofilm were 13.7% and 29.1% of the total substrate carbon hydrolyzed, respectively. Fermentative catabolism was comparable between the two cellulose loadings, with ca. 4% of metabolized sugar carbon being utilized for cell production, while 75.4% and 66.7% of the two cellulose loadings, respectively, were converted to primary carbon metabolites (ethanol, acetic acid, lactic acid, carbon dioxide). However, there was a notable difference in the ethanol-to-acetic acid ratio (g/g), measured to be 0.91 for the low cellulose loading and 0.41 for the high cellulose loading. The results suggest that substrate availability for cell attachment rather than biofilm colonization rates govern the efficiency of cellulose conversion.
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Hollenbeck, Emily C., Alexandra Antonoplis, Chew Chai, Wiriya Thongsomboon, Gerald G. Fuller, and Lynette Cegelski. "Phosphoethanolamine cellulose enhances curli-mediated adhesion of uropathogenicEscherichia colito bladder epithelial cells." Proceedings of the National Academy of Sciences 115, no. 40 (September 19, 2018): 10106–11. http://dx.doi.org/10.1073/pnas.1801564115.
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UropathogenicEscherichia coli(UPEC) are the major causative agents of urinary tract infections, employing numerous molecular strategies to contribute to adhesion, colonization, and persistence in the bladder niche. Identifying strategies to prevent adhesion and colonization is a promising approach to inhibit bacterial pathogenesis and to help preserve the efficacy of available antibiotics. This approach requires an improved understanding of the molecular determinants of adhesion to the bladder urothelium. We designed experiments using a custom-built live cell monolayer rheometer (LCMR) to quantitatively measure individual and combined contributions of bacterial cell surface structures [type 1 pili, curli, and phosphoethanolamine (pEtN) cellulose] to bladder cell adhesion. Using the UPEC strain UTI89, isogenic mutants, and controlled conditions for the differential production of cell surface structures, we discovered that curli can promote stronger adhesive interactions with bladder cells than type 1 pili. Moreover, the coproduction of curli and pEtN cellulose enhanced adhesion. The LCMR enables the evaluation of adhesion under high-shear conditions to reveal this role for pEtN cellulose which escaped detection using conventional tissue culture adhesion assays. Together with complementary biochemical experiments, the results support a model wherein cellulose serves a mortar-like function to promote curli association with and around the bacterial cell surface, resulting in increased bacterial adhesion strength at the bladder cell surface.
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Reinhold-Hurek, Barbara, Tamara Maes, Sabrina Gemmer, Marc Van Montagu, and Thomas Hurek. "An Endoglucanase Is Involved in Infection of Rice Roots by the Not-Cellulose-Metabolizing Endophyte Azoarcus Sp. Strain BH72." Molecular Plant-Microbe Interactions® 19, no. 2 (February 2006): 181–88. http://dx.doi.org/10.1094/mpmi-19-0181.
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The nitrogen-fixing endophyte Azoarcus sp. strain BH72 infects roots of Kallar grass and rice inter- and intra-cellularly and can spread systemically into shoots without causing symptoms of plant disease. Although cellulose or its breakdown products do not support growth, this strain expresses an endoglucanase, which might be involved in infection. Sequence analysis of eglA places the secreted 34-kDa protein into the glycosyl hydrolases family 5, with highest relatedness (40% identity) to endoglucanases of the phytopathogenic bacteria Xanthomonas campestris and Ralstonia solanacearum. Transcriptional regulation studied by eglA:: gusA fusion was not significantly affected by cellulose or its breakdown products or by microaerobiosis. Strongest induction (threefold) was obtained in bacteria grown in close vicinity to rice roots. Visible sites of expression were the emergence points of lateral roots and root tips, which are the primary regions of ingress into the root. To study the role in endophytic colonization, eglA was inactivated by transposon mutagenesis. Systemic spreading of the eglA mutant and of a pilAB mutant into the rice shoot could no longer be detected by polymerase chain reaction. Microscopic inspection of infection revealed that the intracellular colonization of root epidermis cells was significantly reduced in the eglA-mutant BHE6 compared with the wild type and partially restored in the complementation mutant BHRE2 expressing eglA. This provides evidence that Azoarcus sp. endoglucanase is an important determinant for successful endophytic colonization of rice roots, suggesting an active bacterial colonization process.
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Gelhaye, E., H. Petitdemange, and R. Gay. "Characteristics of cellulose colonization by a mesophilic, cellulolytic Clostridium (strain C401)." Research in Microbiology 143, no. 9 (November 1992): 891–95. http://dx.doi.org/10.1016/0923-2508(92)90076-z.
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Matthysse, Ann G., and Susan McMahan. "Root Colonization by Agrobacterium tumefaciens Is Reduced in cel, attB,attD, and attR Mutants." Applied and Environmental Microbiology 64, no. 7 (July 1, 1998): 2341–45. http://dx.doi.org/10.1128/aem.64.7.2341-2345.1998.
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ABSTRACT Root colonization by Agrobacterium tumefaciens was measured by using tomato and Arabidopsis thaliana roots dipped in a bacterial suspension and planted in soil. Wild-type bacteria showed extensive growth on tomato roots; the number of bacteria increased from 103 bacteria/cm of root length at the time of inoculation to more than 107 bacteria/cm after 10 days. The numbers of cellulose-minus and nonattachingattB, attD, and attR mutant bacteria were less than 1/10,000th the number of wild-type bacteria recovered from tomato roots. On roots of A. thalianaecotype Landsberg erecta, the numbers of wild-type bacteria increased from about 30 to 8,000 bacteria/cm of root length after 8 days. The numbers of cellulose-minus and nonattaching mutant bacteria were 1/100th to 1/10th the number of wild-type bacteria recovered after 8 days. The attachment of A. tumefaciens to cut A. thaliana roots incubated in 0.4% sucrose and observed with a light microscope was also reduced with cel andatt mutants. These results suggest that cellulose synthesis and attachment genes play a role in the ability of the bacteria to colonize roots, as well as in bacterial pathogenesis.
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Campion, C., B. Vian, M. Nicole, and F. Rouxel. "A comparative study of carrot root tissue colonization and cell wall degradation by Pythium violae and Pythium ultimum, two pathogens responsible for cavity spot." Canadian Journal of Microbiology 44, no. 3 (March 1, 1998): 221–30. http://dx.doi.org/10.1139/w97-157.
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The process of infection of carrots by Pythium violae and Pythium ultimum, two causes of cavity spot, is described. The first species causes limited root necrosis, the second progressive root rot. Colonization by both species was intracellular and limited within the tissues. Modes of cell wall degradation were studied by staining (PATAg test) and labeling techniques. Pectins were labeled with monoclonal antibodies and cellulose with an exoglucanase-gold complex. Cell wall polysaccharides were degraded differently by the two species. Pythium violae was responsible for degradations, which could be noticeable, especially for high methylesterified pectins, but which occurred after colonization and were localized near the hyphae. The conservation of integrity of diseased tissue was apparently due to the absence of degradation away from the hyphae. In contrast, P. ultimum was responsible for more extensive degradation of pectins and cellulose, which occurred at a relatively greater distance from the hyphae. Degradation of pectins was always more rapid in the cell walls than in the intercellular junctions. This phenomenon led to loss of tissue integrity and could explain the tissue maceration caused by P. ultimum infection. These differences in infection process are discussed in connection with the enzymic potential for degradation of cell wall polysaccharides.Key words: Daucus carota L., Pythium, pectin, cellulose, cytochemistry.
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Vahidi, Mohammad Farhad, Javad Gharechahi, Mehrdad Behmanesh, Xue-Zhi Ding, Jian-Lin Han, and Ghasem Hosseini Salekdeh. "Diversity of microbes colonizing forages of varying lignocellulose properties in the sheep rumen." PeerJ 9 (January 11, 2021): e10463. http://dx.doi.org/10.7717/peerj.10463.
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Background The rumen microbiota contributes strongly to the degradation of ingested plant materials. There is limited knowledge about the diversity of taxa involved in the breakdown of lignocellulosic biomasses with varying chemical compositions in the rumen. Method We aimed to assess how and to what extent the physicochemical properties of forages influence the colonization and digestion by rumen microbiota. This was achieved by placing nylon bags filled with candidate materials in the rumen of fistulated sheep for a period of up to 96 h, followed by measuring forage’s chemical characteristics and community structure of biofilm-embedded microbiota. Results Rumen degradation for all forages appeared to have occurred mainly during the first 24 h of their incubation, which significantly slowed down after 48 h of rumen incubation, depending on their chemical properties. Random Forest analysis predicted the predominant role of Treponema and Butyrivibrio in shaping microbial diversity attached to the forages during the course of rumen incubation. Exploring community structure and composition of fiber-attached microbiota revealed significant differential colonization rates of forages depending on their contents for NDF and cellulose. The correlation analysis highlighted the significant contribution of Lachnospiraceae and Veillonellaceae to fiber degradation in the sheep rumen. Conclusion Our findings suggested that forage cellulose components are critical in shaping the pattern of microbial colonization and thus their final digestibility in the rumen.
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Vahidi, Mohammad Farhad, Javad Gharechahi, Mehrdad Behmanesh, Xue-Zhi Ding, Jian-Lin Han, and Ghasem Hosseini Salekdeh. "Diversity of microbes colonizing forages of varying lignocellulose properties in the sheep rumen." PeerJ 9 (January 11, 2021): e10463. http://dx.doi.org/10.7717/peerj.10463.
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Background The rumen microbiota contributes strongly to the degradation of ingested plant materials. There is limited knowledge about the diversity of taxa involved in the breakdown of lignocellulosic biomasses with varying chemical compositions in the rumen. Method We aimed to assess how and to what extent the physicochemical properties of forages influence the colonization and digestion by rumen microbiota. This was achieved by placing nylon bags filled with candidate materials in the rumen of fistulated sheep for a period of up to 96 h, followed by measuring forage’s chemical characteristics and community structure of biofilm-embedded microbiota. Results Rumen degradation for all forages appeared to have occurred mainly during the first 24 h of their incubation, which significantly slowed down after 48 h of rumen incubation, depending on their chemical properties. Random Forest analysis predicted the predominant role of Treponema and Butyrivibrio in shaping microbial diversity attached to the forages during the course of rumen incubation. Exploring community structure and composition of fiber-attached microbiota revealed significant differential colonization rates of forages depending on their contents for NDF and cellulose. The correlation analysis highlighted the significant contribution of Lachnospiraceae and Veillonellaceae to fiber degradation in the sheep rumen. Conclusion Our findings suggested that forage cellulose components are critical in shaping the pattern of microbial colonization and thus their final digestibility in the rumen.
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Cowles, Kimberly N., David K. Willis, Tyler N. Engel, Jeffrey B. Jones, and Jeri D. Barak. "Diguanylate Cyclases AdrA and STM1987 Regulate Salmonella enterica Exopolysaccharide Production during Plant Colonization in an Environment-Dependent Manner." Applied and Environmental Microbiology 82, no. 4 (December 11, 2015): 1237–48. http://dx.doi.org/10.1128/aem.03475-15.
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ABSTRACTIncreasing evidence indicates that despite exposure to harsh environmental stresses,Salmonella entericasuccessfully persists on plants, utilizing fresh produce as a vector to animal hosts. Among the importantS. entericaplant colonization factors are those involved in biofilm formation.S. entericabiofilm formation is controlled by the signaling molecule cyclic di-GMP and represents a sessile lifestyle on surfaces that protects the bacterium from environmental factors. Thus, the transition from a motile, planktonic lifestyle to a sessile lifestyle may represent a vital step in bacterial success. This study examined the mechanisms ofS. entericaplant colonization, including the role of diguanylate cyclases (DGCs) and phosphodiesterases (PDEs), the enzymes involved in cyclic di-GMP metabolism. We found that two biofilm components, cellulose and curli, are differentially required at distinct stages in root colonization and that the DGC STM1987 regulates cellulose production in this environment independent of AdrA, the DGC that controls the majority ofin vitrocellulose production. In addition, we identified a new function for AdrA in the transcriptional regulation of colanic acid and demonstrated thatadrAand colanic acid biosynthesis are associated withS. entericadesiccation tolerance on the leaf surface. Finally, two PDEs with known roles in motility, STM1344 and STM1697, had competitive defects in the phyllosphere, suggesting that regulation of motility is crucial forS. entericasurvival in this niche. Our results indicate that specific conditions influence the contribution of individual DGCs and PDEs to bacterial success, perhaps reflective of differential responses to environmental stimuli.
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Gelhaye, E., A. Gehin, L. Benoit, and H. Petitdemange. "Effects of cellobiose on cellulose colonization by a mesophilic, cellulolytic Clostridium (strain C401)." Journal of General Microbiology 139, no. 11 (November 1, 1993): 2819–24. http://dx.doi.org/10.1099/00221287-139-11-2819.
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Hamouda, Ragaa A., Fauzia A. K. Qarabai, Fathi S. Shahabuddin, Turki M. Al-Shaikh, and Rabab R. Makharita. "Antibacterial Activity of Ulva/Nanocellulose and Ulva/Ag/Cellulose Nanocomposites and Both Blended with Fluoride against Bacteria Causing Dental Decay." Polymers 15, no. 4 (February 20, 2023): 1047. http://dx.doi.org/10.3390/polym15041047.
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One of the most prevalent chronic infectious disorders is tooth decay. Acids produced when plaque bacteria break down sugar in the mouth cause tooth decay. Streptococcus mutans and Lactobacillus acidophilus are the most prominent species related to dental caries. Innovative biocidal agents that integrate with a biomaterial to prevent bacterial colonization have shown remarkable promise as a result of the rapid advancement of nanoscience and nanotechnology. In this study, Ulva lactuca was used as a cellulose source and reducing agent to synthesize nanocellulose and Ulva/Ag/cellulose/nanocomposites. The characterizations of nanocellulose and Ulva/Ag/cellulose/nanocomposites were tested for FT-IR, TEM, SEM, EDS, XRD, and zeta potential. Ulva/Ag/cellulose/nanocomposites and Ulva/nanocellulose, both blended with fluoride, were tested as an antibacterial against S. mutans ATCC 25175 and L. acidophilus CH-2. The results of the SEM proved that nanocellulose is filament-shaped, and FT-IR proved that the functional groups of Ulva/nanocellulose and Ulva/Ag/cellulose/nanocomposites and cellulose are relatively similar but present some small diffusion in peaks. The TEM image demonstrated that the more piratical size distribution of Ulva/Ag/cellulose/nanocomposites ranged from 15 to 20 nm, and Ulva/nanocellulose ranged from 10 to 15 nm. Ulva/Ag/cellulose/nanocomposites have higher negativity than Ulva/nanocellulose. Ulva/Ag/cellulose/nanocomposites and Ulva/nanocellulose possess antibacterial activity against S. mutans ATCC 25175 and L. acidophilus CH-2, but Ulva/Ag/cellulose/nanocomposites are more effective, followed by that blended with fluoride. It is possible to use Ulva/Ag/cellulose/nanocomposites as an antimicrobial agent when added to toothpaste. It is promising to discover an economic and safe nanocomposite product from a natural source with an antimicrobial agent that might be used against tooth bacteria.
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Firdaus, Maulidan, Muhammad Daniswara, Khoirul Jamaluddin, and Novi Andriani. "Reveal the Potency of Water Hyacinth and Red Ginger Extract as Hydrogel Wound Dressing for Mrsa Diabetic Wound: a Short Review." Natural Science and Advanced Technology Education 30, no. 1 (March 1, 2021): 9–23. http://dx.doi.org/10.53656/nat2021-1.01.
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Methicillin-resistant Staphylococcus aureus (MRSA) bacteria that colonize diabetic foot ulcers can cause dangerous infections and even amputations. To improve the healing process, hydrogel wound dressing loaded with antibacterial agents can be selected as viable alternatives to reduce MRSA colonization and infection. This review highlights the potential use of water hyacinth cellulose (Eichornia crassipes) as a base for hydrogel plaster and red ginger rhizome (Zingiber officinale var. Rubrum) as an antibacterial agent. Comprehensive studies show that water hyacinth weed that contains high cellulose has the potency to be converted into hydrogels. In addition, further studies show that the active compounds of red ginger rhizome extract such as 6-gingerol, gingerenone-A, and 6-shogaol are proven to inhibit MRSA which could be incorporated into hydrogels. These findings prove that the hydrogel derived from water hyacinth cellulose and the active compounds of red ginger extract is very promising for the future as a new alternative to diabetic wound dressing.
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Niu, Dongze, Peng Zhu, Tingting Pan, Changyong Yu, Chunyu Li, Jianjun Ren, and Chuncheng Xu. "Ensiling Improved the Colonization and Degradation Ability of Irpex lacteus in Wheat Straw." International Journal of Environmental Research and Public Health 19, no. 20 (October 21, 2022): 13668. http://dx.doi.org/10.3390/ijerph192013668.
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To develop a non-thermal method to replace steam autoclaving for white-rot fungi fermentation, Irpex lacteus spawn was inoculated in wheat straw (WSI) or ensiled WS (WSI) at varying ratios of 10%, 20%, 30%, 40%, and 50%, and incubated at 28 °C for 28 days to determine the effects of the ensiling and inoculation ratio on the colonization and degradation ability of Irpex lacteus in wheat straw (WS). The results demonstrate that ensiling effectively inhibited the growth of aerobic bacteria and molds, as well as other harmful microorganisms in WS, which created a favorable condition for the growth of I. lacteus. After the treatment of I. lacteus, the pH of EWSI decreased to below 5, while that of WSI, except for the feedstocks of WSI-50%, was around 7, indicating that I. lacteus colonized well in the ensiled WS because the substrates dominated by I. lacteus are generally acidic. Correspondingly, except for the molds in WSI-50% samples, the counts of other microorganisms in WSI, such as aerobic bacteria and molds, were significantly higher than those in EWSI (p < 0.05), indicating that contaminant microorganisms had a competitive advantage in non-ensiled substrates. Incubation with I. lacteus did not significantly affect the cellulose content of all samples. However, the NDS content of EWSI was significantly higher than that of WSI (p < 0.05), and the hemicellulose and lignin contents were significantly lower than the latter (p < 0.05), except for the NDS and hemicellulose contents of WSI-50% samples. Correlation analysis revealed a stronger negative correlation between NDS content and the contents of hemicellulose, cellulose, and lignin in EWSI, which could be caused by the destruction of lignin and hemicellulose and the conversion from structural carbohydrates to fungal polysaccharides or other compounds in NDS form. Even for WSI-50% samples, the sugar yield of WS treated with I. lacteus improved with an increasing inoculation ratio, but the ratio was not higher than that of the raw material. However, the sugar yield of EWSI increased by 51–80%, primarily owing to the degradation of lignin and hemicellulose. Above all, ensiling improves the colonization ability of I. lacteus in WS, which promotes the degradation of lignin and hemicellulose and the enzymic hydrolysis of cellulose, so combining ensiling and I. lacteus fermentation has promising potential in the pretreatment of WS.
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Bassis, Christine M., and Karen L. Visick. "The Cyclic-di-GMP Phosphodiesterase BinA Negatively Regulates Cellulose-Containing Biofilms in Vibrio fischeri." Journal of Bacteriology 192, no. 5 (January 8, 2010): 1269–78. http://dx.doi.org/10.1128/jb.01048-09.
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ABSTRACT Bacteria produce different types of biofilms under distinct environmental conditions. Vibrio fischeri has the capacity to produce at least two distinct types of biofilms, one that relies on the symbiosis polysaccharide Syp and another that depends upon cellulose. A key regulator of biofilm formation in bacteria is the intracellular signaling molecule cyclic diguanylate (c-di-GMP). In this study, we focused on a predicted c-di-GMP phosphodiesterase encoded by the gene binA, located directly downstream of syp, a cluster of 18 genes critical for biofilm formation and the initiation of symbiotic colonization of the squid Euprymna scolopes. Disruption or deletion of binA increased biofilm formation in culture and led to increased binding of Congo red and calcofluor, which are indicators of cellulose production. Using random transposon mutagenesis, we determined that the phenotypes of the ΔbinA mutant strain could be disrupted by insertions in genes in the bacterial cellulose biosynthesis cluster (bcs), suggesting that cellulose production is negatively regulated by BinA. Replacement of critical amino acids within the conserved EAL residues of the EAL domain disrupted BinA activity, and deletion of binA increased c-di-GMP levels in the cell. Together, these data support the hypotheses that BinA functions as a phosphodiesterase and that c-di-GMP activates cellulose biosynthesis. Finally, overexpression of the syp regulator sypG induced binA expression. Thus, this work reveals a mechanism by which V. fischeri inhibits cellulose-dependent biofilm formation and suggests that the production of two different polysaccharides may be coordinated through the action of the cellulose inhibitor BinA.
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Picard, Karine, Yves Tirilly, and Nicole Benhamou. "Cytological Effects of Cellulases in the Parasitism of Phytophthora parasitica by Pythium oligandrum." Applied and Environmental Microbiology 66, no. 10 (October 1, 2000): 4305–14. http://dx.doi.org/10.1128/aem.66.10.4305-4314.2000.
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ABSTRACT The ubiquitous oomycete Pythium oligandrum is a potential biocontrol agent for use against a wide range of pathogenic fungi and an inducer of plant disease resistance. The ability ofP. oligandrum to compete with root pathogens for saprophytic colonization of substrates may be critical for pathogen increase in soil, but other mechanisms, including antibiosis and enzyme production, also may play a role in the antagonistic process. We used transmission electron microscopy and gold cytochemistry to analyze the intercellular interaction between P. oligandrum andPhytophthora parasitica. Growth of P. oligandrum towards Phytophthora cells correlated with changes in the host, including retraction of the plasma membrane and cytoplasmic disorganization. These changes were associated with the deposition onto the inner host cell surface of a cellulose-enriched material. P. oligandrum hyphae could penetrate the thickened host cell wall and the cellulose-enriched material, suggesting that large amounts of cellulolytic enzymes were produced. Labeling of cellulose with gold-complexed exoglucanase showed that the integrity of the cellulose was greatly affected both along the channel of fungal penetration and also at a distance from it. We measured cellulolytic activity of P. oligandrum in substrate-free liquid medium. The enzymes present were almost as effective as those from Trichoderma viride in degrading both carboxymethyl cellulose and Phytophthora wall-bound cellulose. P. oligandrum and its cellulolytic enzymes may be useful for biological control of oomycete pathogens, includingPhytophthora and Pythium spp., which are frequently encountered in field and greenhouse production.
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Nicole, Michel R., and Nicole Benhamou. "Pectin degradation during root decay of rubber trees by Rigidoporus lignosus." Canadian Journal of Botany 71, no. 3 (March 1, 1993): 370–78. http://dx.doi.org/10.1139/b93-041.
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Aplysia gonad lectin, which binds polygalacturonic acid, was complexed to colloidal gold and used for localizing molecules that contain polygalacturonic acid in rubber tree roots infected with the white-rot root fungus Rigidoporus lignosus. Colonization of root tissues was associated with strong wall alteration of phloem cells and with degradation of the compound middle lamella in both the phloem (10 weeks after inoculation) and the xylem (15 weeks after inoculation). Our data suggest that pectin breakdown during root decay likely occurs after cellulose and lignin breakdown and may result from the fungal pectinase activities that were detected in vitro. Released pectin oligomers may act as inducers of both fungal laccase and of the tree defense system during root invasion. Key words: root rotting fungi, rubber, pectin, cellulose, cytochemistry.
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Campodoni, Elisabetta, Margherita Montanari, Samuele M. Dozio, Ellinor B. Heggset, Silvia Panseri, Monica Montesi, Anna Tampieri, Kristin Syverud, and Monica Sandri. "Blending Gelatin and Cellulose Nanofibrils: Biocomposites with Tunable Degradability and Mechanical Behavior." Nanomaterials 10, no. 6 (June 22, 2020): 1219. http://dx.doi.org/10.3390/nano10061219.
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Many studies show how biomaterial properties like stiffness, mechanical stimulation and surface topography can influence cellular functions and direct stem cell differentiation. In this work, two different natural materials, gelatin (Gel) and cellulose nanofibrils (CNFs), were combined to design suitable 3D porous biocomposites for soft-tissue engineering. Gel was selected for its well-assessed high biomimicry that it shares with collagen, from which it derives, while the CNFs were chosen as structural reinforcement because of their exceptional mechanical properties and biocompatibility. Three different compositions of Gel and CNFs, i.e., with weight ratios of 75:25, 50:50 and 25:75, were studied. The biocomposites were morphologically characterized and their total- and macro- porosity assessed, proving their suitability for cell colonization. In general, the pores were larger and more isotropic in the biocomposites compared to the pure materials. The influence of freeze-casting and dehydrothermal treatment (DHT) on mechanical properties, the absorption ability and the shape retention were evaluated. Higher content of CNFs gave higher swelling, and this was attributed to the pore structure. Cross-linking between CNFs and Gel using DHT was confirmed. The Young’s modulus increased significantly by adding the CNFs to Gel with a linear relationship with respect to the CNF amounts. Finally, the biocomposites were characterized in vitro by testing cell colonization and growth through a quantitative cell viability analysis performed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Additionally, the cell viability analysis was performed by the means of a Live/Dead test with Human mesenchymal stem cells (hMSCs). All the biocomposites had higher cytocompatibility compared to the pure materials, Gel and CNFs.
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Pérez-Mendoza, Daniel, Lorena Romero-Jiménez, Miguel Ángel Rodríguez-Carvajal, María J. Lorite, Socorro Muñoz, Adela Olmedilla, and Juan Sanjuán. "The Role of Two Linear β-Glucans Activated by c-di-GMP in Rhizobium etli CFN42." Biology 11, no. 9 (September 17, 2022): 1364. http://dx.doi.org/10.3390/biology11091364.
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Bacterial exopolysaccharides (EPS) have been implicated in a variety of functions that assist in bacterial survival, colonization, and host–microbe interactions. Among them, bacterial linear β-glucans are polysaccharides formed by D-glucose units linked by β-glycosidic bonds, which include curdlan, cellulose, and the new described Mixed Linkage β-Glucan (MLG). Bis-(3′,5′)-cyclic dimeric guanosine monophosphate (c-di-GMP) is a universal bacterial second messenger that usually promote EPS production. Here, we report Rhizobium etli as the first bacterium capable of producing cellulose and MLG. Significant amounts of these two β-glucans are not produced under free-living laboratory conditions, but their production is triggered upon elevation of intracellular c-di-GMP levels, both contributing to Congo red (CR+) and Calcofluor (CF+) phenotypes. Cellulose turned out to be more relevant for free-living phenotypes promoting flocculation and biofilm formation under high c-di-GMP conditions. None of these two EPS are essential for attachment to roots of Phaseolus vulgaris, neither for nodulation nor for symbiotic nitrogen fixation. However, both β-glucans separately contribute to the fitness of interaction between R. etli and its host. Overproduction of these β-glucans, particularly cellulose, appears detrimental for symbiosis. This indicates that their activation by c-di-GMP must be strictly regulated in time and space and should be controlled by different, yet unknown, regulatory pathways.
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Gualdi, Luciana, Letizia Tagliabue, Stefano Bertagnoli, Teresa Ieranò, Cristina De Castro, and Paolo Landini. "Cellulose modulates biofilm formation by counteracting curli-mediated colonization of solid surfaces in Escherichia coli." Microbiology 154, no. 7 (July 1, 2008): 2017–24. http://dx.doi.org/10.1099/mic.0.2008/018093-0.
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Luna, Estrella, Emily Beardon, Sabine Ravnskov, Julie Scholes, and Jurriaan Ton. "Optimizing Chemically Induced Resistance in Tomato Against Botrytis cinerea." Plant Disease 100, no. 4 (April 2016): 704–10. http://dx.doi.org/10.1094/pdis-03-15-0347-re.
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Resistance-inducing chemicals can offer broad-spectrum disease protection in crops, but can also affect plant growth and interactions with plant-beneficial microbes. We have evaluated different application methods of β-aminobutyric acid (BABA) and jasmonic acid (JA) for long-lasting induced resistance in tomato against Botrytis cinerea. In addition, we have studied nontarget effects on plant growth and root colonization by arbuscular mycorrhizal fungi (AMF). Germinating seeds for 1 week in BABA- or JA-containing solutions promoted seed germination efficiency, did not affect plant growth, and induced resistance in 4-week-old plants. When formulating BABA and JA in carboxymethyl cellulose seed coating, only BABA was able to induce resistance in 4-week-old plants. Root treatment of 1-week-old seedlings with BABA or JA also induced resistance in 4-week-old plants. However, this seedling treatment repressed plant growth at higher concentrations of the chemicals, which was particularly pronounced in hydroponically grown plants after BABA treatment. Both seed coating with BABA, and seedling treatments with BABA or JA, did not affect AMF root colonization in soil-grown tomato. Our study has identified commercially feasible application methods of BABA and JA, which induce durable disease resistance in tomato without concurrent impacts on plant growth or colonization by plant-beneficial AMF.
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Menéndez, Esther, Juan Pérez-Yépez, Mercedes Hernández, Ana Rodríguez-Pérez, Encarna Velázquez, and Milagros León-Barrios. "Plant Growth Promotion Abilities of Phylogenetically Diverse Mesorhizobium Strains: Effect in the Root Colonization and Development of Tomato Seedlings." Microorganisms 8, no. 3 (March 14, 2020): 412. http://dx.doi.org/10.3390/microorganisms8030412.
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Mesorhizobium contains species widely known as nitrogen-fixing bacteria with legumes, but their ability to promote the growth of non-legumes has been poorly studied. Here, we analyzed the production of indole acetic acid (IAA), siderophores and the solubilization of phosphate and potassium in a collection of 24 strains belonging to different Mesorhizobium species. All these strains produce IAA, 46% solubilized potassium, 33% solubilize phosphate and 17% produce siderophores. The highest production of IAA was found in the strains Mesorhizobium ciceri CCANP14 and Mesorhizobium tamadayense CCANP122, which were also able to solubilize potassium. Moreover, the strain CCANP14 showed the maximum phosphate solubilization index, and the strain CCANP122 was able to produce siderophores. These two strains were able to produce cellulases and cellulose and to originate biofilms in abiotic surfaces and tomato root surface. Tomato seedlings responded positively to the inoculation with these two strains, showing significantly higher plant growth traits than uninoculated seedlings. This is the first report about the potential of different Mesorhizobium species to promote the growth of a vegetable. Considering their use as safe for humans, animals and plants, they are an environmentally friendly alternative to chemical fertilizers for non-legume crops in the framework of sustainable agriculture.
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D’Agostino, Giulia, Rosalia Merra, Francesco Sottile, Giuseppe Lazzara, and Maurizio Bruno. "Almonds By-Product Microcrystalline Cellulose as Stucco for Wooden Artifacts." Sustainability 15, no. 10 (May 10, 2023): 7800. http://dx.doi.org/10.3390/su15107800.
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Over the years in the field of conservation of cultural heritage, a wide use of traditional products for the plastic reintegration of wooden artifacts has been seen. However, they are usually not designed for this purpose. The present study also shows, in terms of material compatibility, the material most suited for wood restoration, cellulose pulp, from the perspective of a new green approach of reusing waste. Indeed, microcellulose was obtained by simple alkaline treatment from softwood almond shells. In particular, Prunus dulcis Miller (D.A.) Webb. was considered an agro-industrial waste largely available in southern Italy. To value the possibility of using this material in a circular economy framework, a microcellulosic material was used, by adding different binders, to manufacture several stuccos to utilize as wood consolidants. Successively, in order to obtain stuccos with biocidal properties against fungal colonization or insect infestation, to which wooden artifacts are often exposed, cellulose pulp was combined with the essential oil of Thymus capitaus (L.) Hoffmanns. & Link., whose biological properties have been largely reported. The physical flexion properties of all new materials were tested.
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RAUDONIENĖ, Vita, Danguolė BRIDŽIUVIENĖ, Eglė MALACHOVSKIENĖ, and Loreta LEVINSKAITĖ. "Biodegradation of Wood Treated with Copper Based Preservative by Two Dematiaceous Fungi: Alternaria Tenuissima and Ulocladium Consortiale." Materials Science 25, no. 3 (May 10, 2019): 309–15. http://dx.doi.org/10.5755/j01.ms.25.3.20563.
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As cases of treated wood colonization by fungi still happen, the understanding of fungal survival abilities could contribute in the creation of new efficient preservatives. For that reason, two dematiaceous fungi Alternaria tenuissima and Ulocladium consortiale isolated from treated wooden joists with discolorations were tested for their wood decomposition ability and tolerance to a copper based preservative. Our results indicated that the copper based preservative failed to suppress completely cellulose and lignin biodegradation by discoloring fungi studied in wood. Moreover, cellulose degradation was higher in the treated sawdust for both fungi after 30 days than in the untreated. Comparing the results of two strains U. consortiale that is little studied as a wood decomposer, was stronger lignin degrader than A. tenuissima in treated and untreated sawdust. The copper sulphate tolerance test showed that both fungi were able to grow up to 7 mM concentration in a solid medium. DOI: http://dx.doi.org/10.5755/j01.ms.25.3.20563
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Volokita, Michal, Aharon Abeliovich, and M. Inês M. Soares. "Denitrification of groundwater using cotton as energy source." Water Science and Technology 34, no. 1-2 (July 1, 1996): 379–85. http://dx.doi.org/10.2166/wst.1996.0394.
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Microbial removal of nitrate from drinking water was studied in laboratory columns packed with unprocessed short fiber (low quality) cotton (Gossypium hirsutum). Cotton served as the sole chemical and physical substrate for the microbial population. Removal of nitrate was rapidly achieved without the formation of nitrite. Cotton (cellulose)-dependent denitrification was affected by changes in temperature: denitrification rates at 14°C were approximately half of the rates observed at 30°C. The cotton was entirely consumed in the process. In a fresh reactor, colonization of substrate by bacteria appears to be the rate limiting factor in the removal of nitrate.
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Novaes, Arthur B., Ferney Gonzalez Gutierrez, Irani F. Francischetto, and Arthur B. Novaes. "Bacterial Colonization of the External and Internal Sulci and of Cellulose Membranes at Time of Retrieval." Journal of Periodontology 66, no. 10 (October 1995): 864–69. http://dx.doi.org/10.1902/jop.1995.66.10.864.
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Nicole, M., H. Chamberland, D. Rioux, X. Xixuan, G. B. Ouellette, R. A. Blanchette, and J. P. Geiger. "Wood degradation by Phellinus noxius: ultrastructure and cytochemistry." Canadian Journal of Microbiology 41, no. 3 (March 1, 1995): 253–65. http://dx.doi.org/10.1139/m95-035.
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An ultrastructural and cytochemical investigation of the development of Phellinus noxius, a white-rot fungus, in wood chips of Betula papyrifera was done to gain insight into the cellular mechanisms of wood cell wall degradation. Extracellular sheaths and microhyphae were seen to be involved in wood colonization. Close association was observed between these fungal structures and wood cell walls at both early and advanced stages of wood alteration. Fungal sheaths were often seen deep inside host cell walls, sometimes enclosing residual wood fragments. Investigations using gold probes indicated the occurrence of β-1,3-glucans within the fungal sheaths, while β-1,4-glucans were detected only within the fungal septa. The positive reaction with the PATAg test revealed that polysaccharides such as β-1,6-glucans were important components of the sheath. Chitin, pectin, β-glucosides, galactosamine, mannose, sialic acid, fucose, and fimbrial proteins were not found to be present in the sheath. Our data suggest that extracellular sheaths and microphyphae produced by P. noxius during wood cell wall colonization play an important role in wood degradation.Key words: cellulose, Phellinus, sheath, wood degradation.
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Ljaljevic-Grbic, Milica, M. Stupar, Jelena Vukojevic, Ivana Maricic, and Natasa Bungur. "Molds in museum environments: Biodeterioration of art photographs and wooden sculptures." Archives of Biological Sciences 65, no. 3 (2013): 955–62. http://dx.doi.org/10.2298/abs1303955g.
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Pieces of art stored in museum depots and display rooms are subject to fungal colonization that leads to bio-deterioration processes. Deteriorated wooden sculptures and art photographs temporarily stored in the quarantine room of the Cultural Center of Belgrade were subject to mycological analyses. Twelve fungal species were identified on the wooden substratum and five species were detected on photograph surfaces. Trichoderma viride, Chaetomium globosum and Alternaria sp. were the fungi with proven cellulolytic activity detected on the examined cellulose substrata. Indoor air mycobiota were estimated to 210.09 ? 8.06 CFU m-3, and the conidia of fungus Aspergillus niger were the dominant fungal propagules in the air of the examined room.
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Zhu, Xiaoqin, Ming Tang, and Hui Chen. "Delignification and hydrolyzation of mycorrhizal black locust biomass pretreated with aqueous ammonia." BioResources 14, no. 1 (December 12, 2018): 965–76. http://dx.doi.org/10.15376/biores.14.1.965-976.
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Arbuscular mycorrhizae (AM) fungi can increase the biomass of host plants that are used as biofuel feedstock. However, little is known about the effects of AM fungi during aqueous ammonia pretreatment of biomass to remove lignin or on the enzymatic hydrolysis of cellulose. The analysis of mycorrhizal colonization (Rhizophagus irregularis or Glomus versiforme) on stems of black locust (Robinia pseudoacacia) plants in their first and second year of growth revealed that the presence of AM fungi and the growth time significantly influenced the lignin and cellulose content of untreated black locust but had no effect on the content of stems pretreated with aqueous ammonia. The presence of AM fungi and/or the growth time also affected the black locust stem structure and the chemical structure of lignin. Hydrolysis of mycorrhizal and non-mycorrhizal biomass produced similar glucose yields (except for the second-year R. irregularis biomass, which produced significantly less glucose than the other treatments). The results suggest that mycorrhizal black locust biomass is a suitable substrate for biofuel production.
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Ouellette, G. B., R. P. Baayen, M. Simard, and D. Rioux. "Ultrastructural and cytochemical study of colonization of xylem vessel elements of susceptible and resistant Dianthus caryophyllus by Fusarium oxysporum f.sp. dianthi." Canadian Journal of Botany 77, no. 5 (October 16, 1999): 644–63. http://dx.doi.org/10.1139/b99-033.
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The colonization processes of the xylem in the susceptible carnation cv. Early Sam and the resistant cv. Novada were studied ultrastructurally following inoculation with Fusarium oxysporum f.sp. dianthi. Samples from 1 to 3 cm above the incision were collected over 5 weeks and processed following conventional procedures as well as with probes for cellulose, N-acetyl-glucosamine, and pectin. The fungus grew profusely in the vessel lumina of the susceptible cultivar. Some of the colonized vessels were lined with coating material connected to the fungal cell wall and extending into the host cell wall through microfilamentous-like structures. Coatings did not label for pectin or cellulose. The pathogen crossed from one vessel element to another (and at times to parenchyma cells) usually directly through pit membranes; often the invading structures of the fungus appeared to be either only membrane-bound or formed solely of microfilamentous-like entities. The fungus subsequently invaded extensively, generally by means of microhyphae, the vessel intercalary walls from the pit membranes and vessel wall junctures. Microhyphae had thin or imperceptible walls and contained only some of the normal cytoplasmic components. Initially, the invading hyphae dislocated the host cell walls, apparently mechanically more than by lysis; however, more pronounced lysis occurred following general tissue invasion. Host parenchyma cells seemed relatively unaffected, even after the surrounding walls had undergone severe degradation. Colonization of resistant plants was restricted. Degradation of tissues did not occur and microhyphae were not observed. Inoculated vessel elements in the 'Novada' plants contained numerous fungal cells and little occluding material, whereas the surrounding vessels were almost completely occluded. The initially invaded xylem became tangentially compartmentalized by parenchyma cell wall thickenings and by hyperplastic parenchyma. Occasionally, hyperplastic tissues were slightly re-invaded, forming secondary invasion pockets. Vessel-occluding material varied in structure and opacity, not only from vessel to vessel but also within the same vessel, and contained microfilamentous-like structures and other types of fine fibrillar material. Some vessel elements in or near the secondary invasion pockets contained only the finer fibrils that reacted strongly with an antibody specific for pectin. Vessel elements rarely contained tyloses.Key words: cellulose, chitin, Dianthus caryophyllus, Fusarium wilt, gels and gums, host wall degradation, microhyphae, pectin, tyloses.
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Makkar, H. P. S., B. Singh, and S. S. Negi. "Relationship of rumen degradability with microbial colonization, cell wall constituents and tannin levels in some tree leaves." Animal Science 49, no. 2 (October 1989): 299–303. http://dx.doi.org/10.1017/s0003356100032438.
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ABSTRACTRumen microbial attachment to food particles had a significant negative correlation with cell wall contents, cellulose and acid-detergent fibre (ADF) (P< 0·01) and a non-significant correlation with lignin, total phenolic content, condensed tannins and protein precipitation capacity. Microbial colonization was significantly positively correlated within saccodry-matter loss (DML) at 48 h of rumen incubation (P< 0·01). The cell wall contents and ADF were good predictors of DML. The relationship of DML (Y) with cell wall contents(X)and ADF(X')wereY= 1·012 – 0·0011Z,r= –0·89 (P< 0·01, no. = 10) andY= 0·977 – 0·0014X',r= –0·88 (P< 0·01, no. = 10), respectively.
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Rao, Dhana, Jeremy S. Webb, and Staffan Kjelleberg. "Microbial Colonization and Competition on the Marine Alga Ulva australis." Applied and Environmental Microbiology 72, no. 8 (August 2006): 5547–55. http://dx.doi.org/10.1128/aem.00449-06.
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ABSTRACT Pseudalteromonas tunicata and Roseobacter gallaeciensis are biofilm-forming marine bacteria that are often found in association with the surface of the green alga Ulva australis. They are thought to benefit the plant host by producing inhibitory compounds that are active against common fouling organisms. We investigated factors that influence the ability of P. tunicata and R. gallaeciensis to attach to and colonize the plant surface and also the competitive interactions that occur between these organisms and other isolates from U. australis during biofilm formation on the plant surface. A surprisingly high number of P. tunicata cells, at least 108 cells ml−1, were required for colonization and establishment of a population of cells that persists on axenic surfaces of U. australis. Factors that enhanced colonization of P. tunicata included inoculation in the dark and pregrowth of inocula in medium containing cellobiose as the sole carbon source (cellulose is a major surface polymer of U. australis). It was also found that P. tunicata requires the presence of a mixed microbial community to colonize effectively. In contrast, R. gallaeciensis effectively colonized the plant surface under all conditions tested. Studies of competitive interactions on the plant surface revealed that P. tunicata was numerically dominant compared with all other bacterial isolates tested (except R. gallaeciensis), and this dominance was linked to production of the antibacterial protein AlpP. Generally, P. tunicata was able to coexist with competing strains, and each strain existed as microcolonies in spatially segregated regions of the plant. R. gallaeciensis was numerically dominant compared with all strains tested and was able to invade and disperse preestablished biofilms. This study highlighted the fact that microbial colonization of U. australis surfaces is a dynamic process and demonstrated the differences in colonization strategies exhibited by the epiphytic bacteria P. tunicata and R. gallaeciensis.
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Mendoza-Soto, Ana Belén, Amada Zulé Rodríguez-Corral, Adriana Bojórquez-López, Maylin Cervantes-Rojo, Claudia Castro-Martínez, and Melina Lopez-Meyer. "Arbuscular Mycorrhizal Symbiosis Leads to Differential Regulation of Genes and miRNAs Associated with the Cell Wall in Tomato Leaves." Biology 11, no. 6 (June 2, 2022): 854. http://dx.doi.org/10.3390/biology11060854.
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Arbuscular mycorrhizal symbiosis is an association that provides nutritional benefits to plants. Importantly, it induces a physiological state allowing plants to respond to a subsequent pathogen attack in a more rapid and intense manner. Consequently, mycorrhiza-colonized plants become less susceptible to root and shoot pathogens. This study aimed to identify some of the molecular players and potential mechanisms related to the onset of defense priming by mycorrhiza colonization, as well as miRNAs that may act as regulators of priming genes. The upregulation of cellulose synthases, pectinesterase inhibitors, and xyloglucan endotransglucosylase/hydrolase, as well as the downregulation of a pectinesterase, suggest that the modification and reinforcement of the cell wall may prime the leaves of mycorrhizal plants to react faster and stronger to subsequent pathogen attack. This was confirmed by the findings of miR164a-3p, miR164a-5p, miR171e-5p, and miR397, which target genes and are also related to the biosynthesis or modification of cell wall components. Our findings support the hypothesis that the reinforcement or remodeling of the cell wall and cuticle could participate in the priming mechanism triggered by mycorrhiza colonization, by strengthening the first physical barriers upstream of the pathogen encounter.
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Mascarenhas, Marcella, John Dighton, and Georgia A. Arbuckle. "Characterization of Plant Carbohydrates and Changes in Leaf Carbohydrate Chemistry Due to Chemical and Enzymatic Degradation Measured by Microscopic ATR FT-IR Spectroscopy." Applied Spectroscopy 54, no. 5 (May 2000): 681–86. http://dx.doi.org/10.1366/0003702001950166.
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Leaf litter decomposition is largely effected by the enzymatic action of fungal colonizers of leaf material. Microscopic attenuated total reflectance (ATR) infrared spectroscopy would be a useful tool to evaluate changes in leaf litter carbohydrate chemistry over time during the colonization process at the scale of resolution of the fungal hyphae. This paper reports the first studies to use microspectroscopy in the mid-infrared (IR) region to perform analyses within an area of 250 × 250 μm to gain spectra of single species of sugars and complex carbohydrates (cellulose, hemicellulose, lignin) to identify characteristic IR reflectance peaks and to be able to separate the species in complex media. Changes in leaf surface carbohydrate chemistry were interpreted from spectra obtained from leaf material that underwent the following: (1) treatment with acetone (to remove surface waxes), (2) treatment with enzymes, and (3) observation after colonization by fungi. Analysis of spectra obtained from random locations or from the same points on the leaf surface over time permitted changes in carbohydrate chemistry to be detected. Comparative analysis of spectra was carried out by using time-series analysis of variance of selected characteristic peak heights and multivariate statistics.
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Raterman, Erica L., Daniel D. Shapiro, Daniel J. Stevens, Kevin J. Schwartz, and Rodney A. Welch. "Genetic Analysis of the Role ofyfiRin the Ability of Escherichia coli CFT073 To Control Cellular Cyclic Dimeric GMP Levels and To Persist in the Urinary Tract." Infection and Immunity 81, no. 9 (June 17, 2013): 3089–98. http://dx.doi.org/10.1128/iai.01396-12.
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ABSTRACTDuring urinary tract infections (UTIs), uropathogenicEscherichia colimust maintain a delicate balance between sessility and motility to achieve successful infection of both the bladder and kidneys. Previous studies showed that cyclic dimeric GMP (c-di-GMP) levels aid in the control of the transition between motile and nonmotile states inE. coli. TheyfiRNBlocus inE. coliCFT073 contains genes for YfiN, a diguanylate cyclase, and its activity regulators, YfiR and YfiB. Deletion ofyfiRyielded a mutant that was attenuated in both the bladder and the kidneys when tested in competition with the wild-type strain in the murine model of UTI. A doubleyfiRNmutant was not attenuated in the mouse model, suggesting that unregulated YfiN activity and likely increased cytoplasmic c-di-GMP levels cause a survival defect. Curli fimbriae and cellulose production were increased in theyfiRmutant. Expression ofyhjH, a gene encoding a proven phosphodiesterase, in CFT073 ΔyfiRsuppressed the overproduction of curli fimbriae and cellulose and further verified that deletion ofyfiRresults in c-di-GMP accumulation. Additional deletion ofcsgDandbcsA, genes necessary for curli fimbriae and cellulose production, respectively, returned colonization levels of theyfiRdeletion mutant to wild-type levels. Peroxide sensitivity assays and iron acquisition assays displayed no significant differences between theyfiRmutant and the wild-type strain. These results indicate that dysregulation of c-di-GMP production results in pleiotropic effects that disableE. coliin the urinary tract and implicate the c-di-GMP regulatory system as an important factor in the persistence of uropathogenicE. coli in vivo.
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Escudero-Leyva, Efraín, Sofía Vieto, Roberto Avendaño, Diego Rojas-Gätjens, Paola Agüero, Carlos Pacheco, Mavis L. Montero, Priscila Chaverri, and Max Chavarría. "Fungi with history: Unveiling the mycobiota of historic documents of Costa Rica." PLOS ONE 18, no. 1 (January 18, 2023): e0279914. http://dx.doi.org/10.1371/journal.pone.0279914.
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We studied the physicochemical characteristics and mycobiota associated to five key historic documents from Costa Rica, including the Independence Act of Costa Rica from 1821. We used nondestructive techniques (i.e., ATR-FTIR and XRF) to determine paper and ink composition. Results show that some documents are composed of cotton-based paper, whereas others were made of wood cellulose with an increased lignin content. We also determined that the ink employed in some of the documents is ferrogallic. Cultivation and molecular techniques were used to characterize the fungi inhabiting the documents. In total, 22 fungal isolates were obtained: 15 from the wood-cellulose-based documents and seven from the other three cotton-based. We also tested the cellulolytic activity of the recovered fungi; 95% of the fungi presented cellulolytic activity correlated to their ability to cause deterioration of the paper. Results suggest that cotton-based paper is the most resistant to fungal colonization and that most of the isolates have cellulolytic activity. This work increases the knowledge of the fungal diversity that inhabits historic documents and its relationship with paper composition and provides valuable information to develop strategies to conserve and restore these invaluable documents.
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Aht-Ong, Duangdao, Duangduen Atong, and Chiravoot Pechyen. "Surface and Mechanical Properties of Cellulose Micro-Fiber Reinforced Recycle Polyethylene Film." Materials Science Forum 695 (July 2011): 469–72. http://dx.doi.org/10.4028/www.scientific.net/msf.695.469.
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This work involved a study of polymer-fiber composites as biodegradable packaging made from recycled polyethylene (r-PE) and chemical-treated cotton fabric waste micro fibers. A compatibilizer, polyethylene-graft-maleic anhydride (PE-g-MA), was used to improve properties of the composites. Factors affecting composite properties were investigated including % PE-g-MA loading, and % fiber loading. The fiber composites were prepared by melt-blending technique. The materials were first mixed by a twin-screw extruder and shaped into samples by an extrusion blow molding machine. The samples were then characterized for mechanical, and morphological properties. It was found that properties of the composites were improved by adding the compatibilizer. Optimum properties of the composites were found at 10% (wt%) PE-g-MA loading. It was also revealed that tensile strength and modulus was found to increase as the % fiber loading was increased. SEM micrographs confirmed that interfacial bonding between the cellulose fibers and the r-PE matrix was enhanced as fewer voids at the interfaces were revealed by adding the PE-g-MA compatibilizer to the composites. Film formation occurred on all composites even if the polymer itself was inert biodegradation. The microbial colonization affected mainly of surface properties r-PE composites while changes were monitored also in the bulk properties of cellulose microfiber.
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Friberg, Nikolai, and Michael J. Winterbourn. "Effects of native and exotic forest on benthic stream biota in New Zealand: a colonization study." Marine and Freshwater Research 48, no. 3 (1997): 267. http://dx.doi.org/10.1071/mf96094.
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Algal biomass, microbial activity and invertebrate colonization were investigated in 20 streams in the South Island, New Zealand. Sixteen streams drained catchments with native or exotic forest and four were unshaded, non-forested sites. Algal biomass on stones was highest at the unshaded sites and was greater at forested sites east of the Alpine Divide than at forested sites on the western side. Algal biomass on nutrient-diffusion substrata also showed significant location (east > west) and nutrient effects. However, responses to nutrient additions were variable among stream groups, with unshaded and eastern native-forest streams showing the strongest response. Abundances of invertebrates (mainly Chironomidae) colonizing diffusion substrata were positively correlated with algal biomass in eastern native forest streams and unshaded streams but not the other treatments. Microbial activity, expressed as loss in weight of cellulose cloth over a three-week period, was unaffected by location/vegetation type but increased significantly in response to nutrient additions.
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Flores-Félix, José David, Encarna Velázquez, Eustoquio Martínez-Molina, Fernando González-Andrés, Andrea Squartini, and Raúl Rivas. "Connecting the Lab and the Field: Genome Analysis of Phyllobacterium and Rhizobium Strains and Field Performance on Two Vegetable Crops." Agronomy 11, no. 6 (May 31, 2021): 1124. http://dx.doi.org/10.3390/agronomy11061124.
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The legume nodules are a rich source not only of rhizobia but also of endophytic bacteria exhibiting plant growth-promoting mechanisms with potential as plant biostimulants. In this work we analyzed the genomes of Phyllobacterium endophyticum PEPV15 and Rhizobium laguerreae PEPV16 strains, both isolated from Phaseolus vulgaris nodules. In silico analysis showed that the genomes of these two strains contain genes related to N-acyl-homoserine lactone (AHL) and cellulose biosynthesis, involved in quorum sensing and biofilm formation, which are essential for plant colonization. Several genes involved in plant growth promotion such as those related to phosphate solubilization, indole acetic acid production, siderophore biosynthesis and nitrogen fixation were also located in both genomes. When strains PEPV15 and PEPV16 were inoculated in lettuce and carrot in field assays, we found that both significantly increased the yield of lettuce shoots and carrot roots by more than 20% and 10%, respectively. The results of this work confirmed that the genome mining of genes involved in plant colonization and growth promotion is a good strategy for predicting the potential of bacterial strains as crops inoculants, opening new horizons for the selection of bacterial strains with which to design new, effective bacteria-based plant biostimulants.
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Bacakova, Marketa, Julia Pajorova, Tomas Sopuch, and Lucie Bacakova. "Fibrin-Modified Cellulose as a Promising Dressing for Accelerated Wound Healing." Materials 11, no. 11 (November 17, 2018): 2314. http://dx.doi.org/10.3390/ma11112314.
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Dermal injuries and chronic wounds usually regenerate with scar formation. Successful treatment without scarring might be achieved by pre-seeding a wound dressing with cells. We aimed to prepare a wound dressing fabricated from sodium carboxymethylcellulose (Hcel® NaT), combined with fibrin and seeded with dermal fibroblasts in vitro. We fabricated the Hcel® NaT in a porous and homogeneous form (P form and H form, respectively) differing in structural morphology and in the degree of substitution of hydroxyl groups. Each form of Hcel® NaT was functionalized with two morphologically different fibrin structures to improve cell adhesion and proliferation, estimated by an MTS assay. Fibrin functionalization of the Hcel® NaT strongly enhanced colonization of the material with human dermal fibroblasts. Moreover, the type of fibrin structures influenced the ability of the cells to adhere to the material and proliferate on it. The fibrin mesh filling the void spaces between cellulose fibers better supported cell attachment and subsequent proliferation than the fibrin coating, which only enwrapped individual cellulose fibers. On the fibrin mesh, the cell proliferation activity on day 3 was higher on the H form than on the P form of Hcel® NaT, while on the fibrin coating, the cell proliferation on day 7 was higher on the P form. The Hcel® NaT wound dressing functionalized with fibrin, especially when in the form of a mesh, can accelerate wound healing by supporting fibroblast adhesion and proliferation.
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Naumova, E. I., T. Yu Chistova, A. A. Varshavskii, and G. K. Zharova. "Functional Diversity of Morphologically Similar Digestive Organs in Muroidea Species." Biology Bulletin 48, no. 3 (May 2021): 331–39. http://dx.doi.org/10.1134/s1062359021020084.
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Abstract We examine possible ways of functional adjustment of morphologically similar alimentary tracts in rodents with different dietary specializations. We study the structure of stomach and gut epithelial surface as well as the features of its colonization with microorganisms in five gerbil species: Psammomys obesus, Meriones crassus, Gerbillus henleyi, G. andersoni, and G. dasyurus. Data on the morphological diversity of mucosa-associated microbiota have been obtained and confirmed by the results of previous microbiology studies. Species differences in chymus acidity associated with dietary specialization have been determined. Variations in the activity of the endoglucanase microbial enzyme, which is crucial for rodents fed on cellulose-containing food, have also been detected. The importance of microbiota for functional adaptations to various food types in rodents with morphologically similar digestive tracts has been evaluated.
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Karaismailoglu, Mehmet Cengiz. "Seed mucilage content in Aethionema W.T. aiton species and their significance in systematic and ecological aspects." Bangladesh Journal of Botany 47, no. 3 (October 28, 2018): 445–49. http://dx.doi.org/10.3329/bjb.v47i3.38682.
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The seeds of the seven Aethionema taxa, namely A. syriacum (Boiss.) Bornm., A. froedinii Rech., A. arabicum (L.) Andrz. ex DC., A. speciosum Boiss. et Huet. subsp. speciosum, A. saxatile (L.) R. Br., A. armenum Boiss. and A. grandiflorum Boiss. et Hohen. were found to have mucilage cells on the surface, and they produce a slippery liquid during hydration. The mucilage in the examined taxa consisted of the pectin or cellulose. Mucilage cells were found to have different anatomical layers in seeds. Moreover, there were differences in columellae shapes in Aethionema taxa, which are prominent, flattened or reduced shapes. In addition, soil adhesion capacities of the taxa ranged from 28 to 356 mg. The presence of mucilage can play a key role in seed dispersion and colonization for the new habitat in Aethionema taxa.