Cellulose Degradation by Mesophilic Anaerobic Bacteria

1990 ◽  
pp. 371-392
Keyword(s):  
Cellulose Degradation ◽  
Anaerobic Bacteria

scholarly journals Cellulose- and Xylan-Degrading Thermophilic Anaerobic Bacteria from Biocompost

2011 ◽  
Vol 77 (7) ◽  
pp. 2282-2291 ◽  
Author(s):  
M. V. Sizova ◽  
J. A. Izquierdo ◽  
N. S. Panikov ◽  
L. R. Lynd
Keyword(s):  
Enrichment Culture ◽  
Cellulose Degradation ◽  
Phylogenetic Analyses ◽  
Glycosyl Hydrolase ◽  
Anaerobic Bacteria ◽  
Xylanase Activity ◽  
Cellulase Activity ◽  
Lag Phase ◽  
Fermentation Products ◽  
Clostridium Clariflavum

ABSTRACTNine thermophilic cellulolytic clostridial isolates and four other noncellulolytic bacterial isolates were isolated from self-heated biocompost via preliminary enrichment culture on microcrystalline cellulose. All cellulolytic isolates grew vigorously on cellulose, with the formation of either ethanol and acetate or acetate and formate as principal fermentation products as well as lactate and glycerol as minor products. In addition, two out of nine cellulolytic strains were able to utilize xylan and pretreated wood with roughly the same efficiency as for cellulose. The major products of xylan fermentation were acetate and formate, with minor contributions of lactate and ethanol. Phylogenetic analyses of 16S rRNA and glycosyl hydrolase family 48 (GH48) gene sequences revealed that two xylan-utilizing isolates were related to aClostridium clariflavumstrain and represent a distinct novel branch within the GH48 family. Both isolates possessed high cellulase and xylanase activity induced independently by either cellulose or xylan. Enzymatic activity decayed after growth cessation, with more-rapid disappearance of cellulase activity than of xylanase activity. A mixture of xylan and cellulose was utilized simultaneously, with a significant synergistic effect observed as a reduction of lag phase in cellulose degradation.

scholarly journals Genomic and functional analyses of fungal and bacterial consortia that enable lignocellulose breakdown in goat gut microbiomes

2021 ◽  
Author(s):  
Xuefeng Peng ◽  
St. Elmo Wilken ◽  
Thomas S. Lankiewicz ◽  
Sean P. Gilmore ◽  
Jennifer L. Brown ◽  
...  
Keyword(s):  
Plant Biomass ◽  
Cellulose Degradation ◽  
Anaerobic Bacteria ◽  
Short Chain Fatty Acids ◽  
Division Of Labour ◽  
Microbial Consortia ◽  
Bacterial Consortia ◽  
Green Biotechnology ◽  
Enrichment Experiments ◽  
Bacteria And Fungi

AbstractThe herbivore digestive tract is home to a complex community of anaerobic microbes that work together to break down lignocellulose. These microbiota are an untapped resource of strains, pathways and enzymes that could be applied to convert plant waste into sugar substrates for green biotechnology. We carried out more than 400 parallel enrichment experiments from goat faeces to determine how substrate and antibiotic selection influence membership, activity, stability and chemical productivity of herbivore gut communities. We assembled 719 high-quality metagenome-assembled genomes (MAGs) that are unique at the species level. More than 90% of these MAGs are from previously unidentified herbivore gut microorganisms. Microbial consortia dominated by anaerobic fungi outperformed bacterially dominated consortia in terms of both methane production and extent of cellulose degradation, which indicates that fungi have an important role in methane release. Metabolic pathway reconstructions from MAGs of 737 bacteria, archaea and fungi suggest that cross-domain partnerships between fungi and methanogens enabled production of acetate, formate and methane, whereas bacterially dominated consortia mainly produced short-chain fatty acids, including propionate and butyrate. Analyses of carbohydrate-active enzyme domains present in each anaerobic consortium suggest that anaerobic bacteria and fungi employ mostly complementary hydrolytic strategies. The division of labour among herbivore anaerobes to degrade plant biomass could be harnessed for industrial bioprocessing.

Application of commercial test-systems to identify gram-negative facultatively anaerobic bacteria

2016 ◽  
Vol 3 (1) ◽  
pp. 43-48 ◽  
Author(s):  
V. Patyka ◽  
L. Butsenko ◽  
L. Pasichnyk
Keyword(s):  
Erwinia Amylovora ◽  
Anaerobic Bacteria ◽  
Biochemical Properties ◽  
Test System ◽  
Phytopathogenic Bacteria ◽  
Gram Negative ◽  
Test Systems ◽  
Facultatively Anaerobic ◽  
Microbiological Methods

Aim. To validate the suitability of commercial API 20E test-system (bioMerieux) for the identifi cation and characterization of facultative gram-negative phytopathogenic bacterial isolates. Methods. Conventional mi- crobiological methods, API 20E test-system (bioMerieux) according to the manufacturer’s instructions. Re- sults. The identifi cation results for Erwinia amylovora, Pectobacterium carotovorum and Pantoea agglome- rans isolates were derived from the conventional and API 20E test systems, which, were in line with the literature data for these species. The API 20E test-system showed high suitability for P. agglomerans isolates identifi cation. Although not all the species of facultatively anaerobic phytopathogenic bacteria may be identi- fi ed using API 20E test-system, its application will surely allow obtaining reliable data about their physiologi- cal and biochemical properties, valuable for identifi cation of bacteria, in the course of 24 h. Conclusions. The results of tests, obtained for investigated species while using API 20E test-system, and those of conventional microbiological methods coincided. The application of API 20E test-system (bioMerieux) ensures fast obtain- ing of important data, which may be used to identify phytopathogenic bacteria of Erwinia, Pectobacterium, Pantoea genera.

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