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Insect Science 2010年第3期17卷 291-302页

作者： Theresa E. Rogers Joy Doran-Peterson Microbiology Department University of Georgia Athens Georgia USA

In forested stream ecosystems of the north and eastern United States, larvae of the aquatic crane fly Tipula abdominalis are important shredders of leaf litter detritus. T. abdominalis larvae harbor a dense and diverse microbial community in their hindgut that may aide in the degradation oflignocellulose. In this study, the activities ofcellulolytic and hemicellulolytic enzymes were demonstrated from hindgut extracts and from bacterial isolates using model sugar substrates. One of the bacterial isolates was further characterized as a member of the family Microbacteriaceae. Taxonomic position of the isolate within this family was determined by a polyphasic approach, as is commonly employed for the separation of genera within the family Microbacteriaceae. The bacterial isolate is Gramtype positive, motile, non-sporulating, and rod-shaped. The G ＋ C content of the DNA is 64.9 mol%. The cell wall contains B2y type peptidoglycan, D- and L-diaminobutyric acid as the diamino acid, and rhamnose as the predominant sugar. The predominant fatty acids are 12-methyltetradecanoic acid （ai-C15：0） and 14-methylhexadecanoic acid （ai-C17：0）. The isolate forms a distinct lineage within the family Microbacteriaceae, as determined by 16S rRNA sequence analysis. We propose the name Crocebacterium ilecola gen. nov., sp. nov., to accommodate this bacterial isolate. The type species is T202T （ATCC BAA-1359; GenBank Accession DQ826511）.

关键词： cellulolytic hemicellulolytic hindgut

Soluble Carbohydrates Repress the cellulolytic Activity of Clostridium cellulovorans and Eubacterium cellulosolvens

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Journal of Agricultural Science and Technology(A) 2015年第1期5卷 15-24页

作者： Benjamin Gay Blair Kevin Lee Anderson Department of Biology Jacksonville State University Jacksonville AL 36265 USA Department of Biology Arkansas State University Beebe AR 7201 USA

Studies have provided indirect evidence that cellulolytic activity of some anaerobic bacteria is repressed by carbohydrates, such as glucose. This effect is known as carbon catabolite repression （CCR）. Previous work has found that cellulolytic activity of Clostridium cellulovorans and Eubacterium cellulosolvens are regulated. Many cellulolytic systems of these organisms are expressed only in the presence of cellulose or cellobiose （the disaccharide of cellulose）. Some of these cellulose-induced systems also appear subject to CCR when more soluble substrates, such as glucose, are also available. To determine if such repression directly effects cellulolytic activity of C. cellulovorans and E. cellulosolvens, these organisms were cultivated in media containing a glucose analog. We then measured the ability of low levels of analog to inhibit growth of the organisms when cellobiose or cellulose were the energy substrates. Our results found that growth of both C. cellulovorans and E. cellulosolvens in cellobiose-containing medium are strongly inhibited by glucose analogs. In addition, both organisms exhibited delayed and slower growth in cellulose-containing medium when a glucose analog was added. These results provide direct demonstration that these cellulolytic bacteria are subject to CCR. This repression of cellulolysis may affect both of these organisms＇ ability to serve as industrial platforms for biomass degradation, and may interfere with the contribution of E. cellulosolvens toward animal digestion of cellulose. These results were also in sharp contrast to what has been reported regarding CCR activity in Clostridium cellulolyticum, which actively expresses cellulases in the presence of low levels of glucose.

关键词： cellulolytic anaerobic bacteria catabolite repression cellulolysis cellulose degradation.

Effects of Facultative Anaerobic cellulolytic Bacteria and Nitrogen-fixing Bacteria Isolated from Cow Rumen Fluid on Rumen Fermentation and Dry Matter Degradation in Vitro

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Journal of Northeast Agricultural University(English Edition) 2020年第1期27卷 49-59页

作者： Zhang Mei-mei Li Yan-fang Liu Da-sen College of Animal Sciences and Technology Northeast Agricultural UniversityHarbin 150030China College of Science Northeast Agricultural UniversityHarbin 150030China

The purpose of the paper was to study the effects of cellulolytic bacteria(CB)mixed with nitrogen-fixing bacteria(NFB)on fermentation in *** CB strains and seven NFB strains were isolated from numen fluid of three Holstein *** onhigher activity of cellulose or nitrogenase,three CB types[CB-2(KT725624),CB-5(KT725623)and CB-6(KT725622)]and one NFB type[NFB-3(KT735054)]were screened out,*** parts were included in this *** first part explored the optimal mixed ratio of CB to NFB through inoculating filter paper medium with the bacteria of 2×10^5 cfu·mL^-*** to CMCase and FPase activities in the medium,the ratio of 4 to 1 was proven to be more *** the second part,rumen fermentation in vitro was conducted at 4:1 of CB to NFB,aiming at studying the effects of mixed *** groups were classified,namely,control group(no bacteria),Group 1(CB-2+NFB-3),Group 2(CB-5+NFB-3),Group 3(CB-6+NFB-3),Group 4(NFB-3)and Group 5(CB-6).All the experimental groups had the same amount of bacteria(4×10^6 cfu·mL^-1)in the fermentation *** were collected at 2,4,8,12 and 24 h of *** with the groups with CB or NFB alone,gas production,dry matter degradability and bacterial protein expressions in the mixed groups ***,NH3-N concentration decreased and p H was ***,related values among three mixed groups were significantly different;values in Group 2 were the best.

关键词： rumen cellulolytic bacterium nitrogen-fixing bacterium mixed culture in vitro fermentation

The cellulolytic Bacteria <i>R. albus</i>for Improving the Efficiency of Microbial Fuel Cell

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Journal of Sustainable Bioenergy Systems 2018年第2期8卷 36-46页

作者： Rebecca Chung Diane J. Moon Yoo Na Chang David S. Chung Taekwon Kong Justin Kim Centreville High School Clifton VA USA The Gwinnett School of Mathematics Science and Technology Lawrenceville GA USA Korean Minjok Leadership Academy Gangwon-do Korea School of Arts and Sciences Brown University Providence RI USA Department of Chemistry College of Arts & Sciences Washington University St. Louis MO USA School of Art & Sciences University of Pennsylvania Philadelphia PA USA

The current study has been undertaken to examine the beneficial effect in the power output of a microbial fuel cell (MFC) by adding cellulolytic bacteria Ruminococcus albus (R. albus) into the anodic chamber. Mediator-less H-type MFCs were set up where the anode chamber contained anaerobic digester microorganisms as inocula on finely ground pine tree (Avicel) at 2% (w/v) and the cathode chamber of 10mM phosphate buffered saline conductive solution, both separated by a cation exchange membrane. The functioning of the MFCs for generation of electrical power and the amounts of gaseous byproducts was monitored over a 9-day period. The addition of cellulolytic bacteria caused an increase of average power density from 7.9 m W/m2 to19.5 m W/m2, about 245% increase over a 9-day period. For both groups of MFCs;with R. albus and the control, the head space gases collected were methane and CO2. While the methane: CO2 ratios were found unchanged at 1.7:1 throughout the 9 days of operation, the total gas production increased from 248 mL to 319 mL due to the presence of R. albus addition. This study confirms that whereas the biocatalytic activity of anode microbial population determines the energy production, the addition of external cellulolytic bacteria into anode microbial population can improve and extend the biomass utilization.

关键词： Microbial Fuel Cell (MFC) cellulolytic Bacteria Microorganism R. albus

Distribution of Myxomycetes on Varied Leaf Litter Types in a Mixed Forest in Warm-Temperate Western Japan

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Open Journal of Forestry 2015年第7期5卷 686-696页

作者： Kazunari Takahashi Okayama University of Science Senior High School Okayama City Japan

Myxomycete assemblages were compared on various leaf litters of different vegetation types in a local mixed forest consisting of deciduous and evergreen trees in western Japan. A total of 33 myxomycete species were recorded and associated with the chemical and biological environments of leaf litters under natural condition of the forest floor. Different myxomycete assemblages were found on different sites under the dominant trees in a short distance apart (300 m). A site of Prunus jamasakura tree yielded 21 species, a Quercus glauca tree yielded 20 species, an Ilex pedunculosa tree yielded 12 species, and two Quercus serrata trees yielded 13 and 14 species, respectively. Non-metric multidimensional scaling demonstrated that the myxomycete assemblages were closely related to the litter types of deciduous and evergreen trees, and both litter pH and cellulolytic activity influenced distribution of myxomycete species. Species richness was higher in leaf litters with higher pH than in leaf litters with more acidic pH such as I. pedunculosa litter. The dominant tree litter and litter pH strongly influenced the species distribution of foliicolous myxomycetes in a local mixed forest.

关键词： cellulolytic Activity Dominant Trees Foliicolous Myxomycetes Litter pH