Electron microscopic study of the methylcellulose-mediated detachment of cellulolytic rumen bacteria from cellulose fibers

1987 ◽  
Vol 33 (3) ◽  
pp. 267-272 ◽  
Author(s):  
H. Kudo ◽  
K.-J. Cheng ◽  
J. W. Costerton
Keyword(s):  
Carbon Sources ◽  
Cellulose Fibers ◽  
Bacterial Attachment ◽  
Crystalline Cellulose ◽  
Rumen Bacteria ◽  
Cellulolytic Bacteria ◽  
Electron Microscopic ◽  
Insoluble Substrate ◽  
Pure Cultures ◽  
Cellulose Surface

The presence of methylellulose prevents the attachment of cellulolytic rumen bacteria to cellulose fibers. The addition of methylcellulose to pure cultures of these organisms in which the cells are already adherent to cellulose causes their detachment from this insoluble substrate and the inhibition of their growth. Methylcellulose is not used as a carbon source by these organisms and has no effect on their growth when glucose and cellobiose are the carbon sources. Attached cells of Bacteroides succinogenes orient themselves in the plane of the individual cellulose fibers and their methylcellulose-induced detachment, which is complete (almost 100%), leaves grooves where the cellulose has been digested. Attached cells of Ruminococcus albus colonize the cellulose in a looser and less regular pattern and their almost complete methylcellulose-induced detachment leaves less regular pits in the cellulose surface. On the other hand, attached cells of Ruminococcus flavefaciens colonize the cellulose surface in a random orientation by means of a discernible exopolysaccharide network, and their less complete methylcellulose-induced detachment leaves no residual impressions on the cellulose surface. These data support the suggestion that bacterial attachment is necessary for the digestion of highly ordered crystalline cellulose, and that cellulolytic species differ in the nature of their attachment to this insoluble substrate and in the nature of their enzymatic attack. Methylcellulose is an effective agent for detaching major rumen cellulolytic bacteria from their cellulosic substrate.

Esterase activity of pure cultures of rumen bacteria as expressed by the hydrolysis of p-nitrophenylpalmitate

1990 ◽  
Vol 36 (8) ◽  
pp. 585-589 ◽  
Author(s):  
J. P. Fay ◽  
K. D. Jakober ◽  
K.-J. Cheng ◽  
J. W. Costerton
Keyword(s):  
Esterase Activity ◽  
Rumen Content ◽  
Rumen Bacteria ◽  
Cellulolytic Bacteria ◽  
Level Of Activity ◽  
Pure Cultures ◽  
General Esterase ◽  
Particle Association ◽  
Hydrolysis Of

Seventy-four strains of rumen bacteria comprising 20 genera were tested for the ability to hydrolyze p-nitrophenylpalmitate (PNPP-C16). This ability was detectable in all cultures tested, but the level of activity was quite variable. Known lipolytic strains of these bacteria showed generally low levels of activity in this assay, which suggests that the hydrolysis of this artificial substrate indicates a general esterase activity and not a lipase activity, as reported in the literature. The highest activity was found to occur in strains known to be feed-particle-associated digesters of starch, pectin and cellulose. In fractionated rumen contents, p-nitro-phenylpalmitase activity was largely associated with feed particles. Although the in vivo role of the enzymes that hydrolyze PNPP-C16 remains obscure, it appears that they are primarily of microbial origin, and may be important in hydrolyzing ester bond-containing compounds from plant material. Key words: Ruminobacter amylophilus, feed-particle association, lipolysis, cellulolytic bacteria, fractionated rumen content.

Isolation and identification of rumen bacteria capable of anaerobic rutin degradation

1969 ◽  
Vol 15 (12) ◽  
pp. 1365-1371 ◽  
Author(s):  
K. -J. Cheng ◽  
G. A. Jones ◽  
F. J. Simpson ◽  
M. P. Bryant
Keyword(s):  
Volatile Fatty Acids ◽  
Rumen Fluid ◽  
Anaerobic Bacteria ◽  
Heterocyclic Ring ◽  
Ring Structure ◽  
Water Soluble ◽  
Rumen Bacteria ◽  
Isolation And Identification ◽  
Pure Cultures ◽  
Rutin Degradation

Fifteen strains of bacteria capable of degrading rutin anaerobically were isolated from bovine rumen contents and identified by morphological and biochemical evidence as strains of Butyrivibrio sp. Three cultures from a laboratory collection of 53 strains of rumen bacteria also used rutin anaerobically. Two, Butyrivibrio fibrisolvens D1 and Selenomonas ruminantium GA192, cleaved the glycosidic bond of rutin and fermented the sugar but did not degrade the insoluble aglycone produced; the third strain, Peptostreptococcus sp. B178, degraded the substrate to soluble products. Butyrivibrio sp. C3 degraded rutin, quercitrin, and naringin to water-soluble products, showing that the organism cleaved the heterocyclic ring of these compounds. Butyrivibrio sp. C3 fermented the sugar moiety of hesperidin but did not cleave the heterocyclic ring. It did not attack quercetin, taxifolin, protocatechuic acid, or phloroglucinol. In a medium containing rumen fluid, Butyrivibrio sp. C3 degraded rutin more than twice as fast as it did in a medium containing enzymatic casein hydrolyzate, volatile fatty acids, yeast extract, and hemin in place of rumen fluid.The observations reported in this paper are believed to represent the first recorded demonstration of degradation of the heterocyclic ring structure of rutin and other bioflavonoids in pure cultures of anaerobic bacteria.

scholarly journals Ability of the soil cellulolytic bacteria to colonize endophytic niche of barley grains

2020 ◽  
Author(s):  
O.V. Sviridova ◽  
◽  
N.I. Vorobyov ◽  
Ya.V. Pukhalsky ◽  
O.N. Kurchak ◽  
...  
Keyword(s):  
Micrococcus Luteus ◽  
Growing Season ◽  
Barley Straw ◽  
Mineral Fertilizers ◽  
Plant Residues ◽  
Cellulolytic Bacteria ◽  
Biological Product ◽  
Presowing Treatment ◽  
Pure Cultures ◽  
Barley Grains

To identify microorganisms that can penetrate into the endophytic niche of the grain of barley plants, many years of vegetative experiments were conducted on sod-podzolic soil without the use of mineral fertilizers. In the non-growing season, a biological product, consisting of cellulolytic association of bacteria with genotypic passport, decomposed barley straw. Presowing treatment of seeds was not carried out, therefore, during the growing season; local microorganisms decomposing plant residues could be present in the barley rhizosphere. After six years of rotation of barley plants, the microbiological composition of its seed niche was studied. As a result, it was found that in the seeds of barley bacteria are present in an amount of 240 ± 20 CFU/g of grain. Isolated pure cultures of microorganisms were identified as Cellulomonas gelida, Micrococcus luteus and Bacillus licheniformis by the sequence of ITS fragments of 16S rRNA. These types of bacteria were also present in the used biological product. Based on the research conducted, it can be assumed, that permanent cultivation of barley plants and sowing of seeds of the previous year can contribute to the formation of effective microbial and plant biosystems that are resistant to environmental stress.

Cellulase activity during the growth of Achlya bisexualis on glucose, cellulose, and selected polysaccharides

1978 ◽  
Vol 56 (16) ◽  
pp. 1974-1981 ◽  
Author(s):  
W. H. Miele ◽  
A. E. Linkins
Keyword(s):  
Carbon Sources ◽  
Cellulase Activity ◽  
Extracellular Enzyme ◽  
Dry Weight ◽  
Soluble Form ◽  
Electron Microscopic ◽  
Transmission Electron ◽  
Transmission Electron Microscopic ◽  
Scanning Electron Microscopic ◽  
Achlya Bisexualis

The antheridial strain of the dioecious water mold Achlya bisexualis was grown in chemically defined media using glucose, cellobiose, and selected polysaccharides as carbon sources. Growth and cellulase levels were measured with media containing glucose, cellobiose, and cellulose. Evaluation of cellulase activity in the medium by viscometric and reducing sugar generation assays suggests that cellulase plays a significant role in degrading cellulose for uptake and catabolism by A. bisexualis. Cellulase in glucose-grown cultures exists as a soluble extracellular enzyme complex, while in cellulose-grown cultures much of the enzyme is absorbed to the cellulose. Elution of the cellulose substrate after 96 h growth with NaCl-fortified buffer releases absorbed cellulase in a soluble form. The absorption of cellulase to the substrate and possibly the cell walls of A. bisexualis could account for the rapid loss in dry weight of A. bisexualis during culture on cellulose in a closed system. Scanning electron microscopic (SEM) examination of the walls of A. bisexualis shows disruption in cellulose cultures, which is not evident for glucose-or cellobiose-grown hyphae. Transmission electron microscopic (TEM) photomicrographs show a significant reduction in the wall thickness of cellulose-grown hyphae as compared with glucose-grown samples. This evidence suggests that the enzyme(s) produced during growth on cellulose is (are) capable of binding as an active hydrolase to walls of A. bisexualis or to the cellulosic substrate.

Interactions between Treponema bryantii and cellulolytic bacteria in the in vitro degradation of straw cellulose

1987 ◽  
Vol 33 (3) ◽  
pp. 244-248 ◽  
Author(s):  
H. Kudo ◽  
K.-J. Cheng ◽  
J. W. Costerton
Keyword(s):  
Plant Cell Wall ◽  
Bacterial Species ◽  
Barley Straw ◽  
Cellulolytic Bacteria ◽  
Morphological Examination ◽  
Cellulose Digestion ◽  
Acid Generation ◽  
Pure Cultures ◽  
Treponema Bryantii

To assess the contribution of individual bacterial species to the overall process of cellulose digestion in the rumen, cellulolytic bacteria (Bacteroides succinogenes and Ruminococcus albus) were tested as pure cultures and as cocultures with noncellulolytic Treponema bryantii. In studies of in vitro barley straw digestion, Treponema cocultures surpassed pure cultures of the cellulolytic organisms in dry matter disappearance, volatile fatty acid generation, and in the production of succinic acid, lactic acid, and ethanol. Morphological examination, by electron microscopy, showed that cells of T. bryantii associate with the plant cell wall materials in straw, but that cellulose digestion occurs only when these organisms are present with cellulolytic species such as B. succinogenes. These results show that cellulolytic bacteria interact with noncellulolytic Treponema to promote the digestion of cellulosic materials.

scholarly journals Genome Sequence of the Cellulolytic Gliding Bacterium Cytophaga hutchinsonii

2007 ◽  
Vol 73 (11) ◽  
pp. 3536-3546 ◽  
Author(s):  
Gary Xie ◽  
David C. Bruce ◽  
Jean F. Challacombe ◽  
Olga Chertkov ◽  
John C. Detter ◽  
...  
Keyword(s):  
Gliding Motility ◽  
Open Reading Frames ◽  
Crystalline Cellulose ◽  
Cellulolytic Bacteria ◽  
Cytophaga Hutchinsonii ◽  
Type Iv ◽  
Flavobacterium Johnsoniae ◽  
Anchoring Proteins ◽  
Genes Encoding ◽  
Gliding Bacterium

ABSTRACT The complete DNA sequence of the aerobic cellulolytic soil bacterium Cytophaga hutchinsonii, which belongs to the phylum Bacteroidetes, is presented. The genome consists of a single, circular, 4.43-Mb chromosome containing 3,790 open reading frames, 1,986 of which have been assigned a tentative function. Two of the most striking characteristics of C. hutchinsonii are its rapid gliding motility over surfaces and its contact-dependent digestion of crystalline cellulose. The mechanism of C. hutchinsonii motility is not known, but its genome contains homologs for each of the gld genes that are required for gliding of the distantly related bacteroidete Flavobacterium johnsoniae. Cytophaga-Flavobacterium gliding appears to be novel and does not involve well-studied motility organelles such as flagella or type IV pili. Many genes thought to encode proteins involved in cellulose utilization were identified. These include candidate endo-β-1,4-glucanases and β-glucosidases. Surprisingly, obvious homologs of known cellobiohydrolases were not detected. Since such enzymes are needed for efficient cellulose digestion by well-studied cellulolytic bacteria, C. hutchinsonii either has novel cellobiohydrolases or has an unusual method of cellulose utilization. Genes encoding proteins with cohesin domains, which are characteristic of cellulosomes, were absent, but many proteins predicted to be involved in polysaccharide utilization had putative D5 domains, which are thought to be involved in anchoring proteins to the cell surface.

scholarly journals The Catabolite Repressor/Activator Cra Is a Bridge Connecting Carbon Metabolism and Host Colonization in the Plant Drought Resistance-Promoting Bacterium Pantoea alhagi LTYR-11Z

2018 ◽  
Vol 84 (13) ◽  
Author(s):  
Lei Zhang ◽  
Muhang Li ◽  
Qiqi Li ◽  
Chaoqiong Chen ◽  
Meng Qu ◽  
...  
Keyword(s):  
Carbon Source ◽  
Carbon Metabolism ◽  
Carbon Sources ◽  
Endophytic Bacterium ◽  
Bacterial Attachment ◽  
Gene Encoding ◽  
Wheat Roots ◽  
Host Colonization ◽  
Content Type

ABSTRACT Efficient root colonization is a prerequisite for application of plant growth-promoting (PGP) bacteria in improving health and yield of agricultural crops. We have recently identified an endophytic bacterium, Pantoea alhagi LTYR-11Z, with multiple PGP properties that effectively colonizes the root system of wheat and improves its growth and drought tolerance. To identify novel regulatory genes required for wheat colonization, we screened an LTYR-11Z transposon (Tn) insertion library and found cra to be a colonization-related gene. By using transcriptome (RNA-seq) analysis, we found that transcriptional levels of an eps operon, the ydiV gene encoding an anti-FlhD 4 C 2 factor, and the yedQ gene encoding an enzyme for synthesis of cyclic dimeric GMP (c-di-GMP) were significantly downregulated in the Δ cra mutant. Further studies demonstrated that Cra directly binds to the promoters of the eps operon, ydiV , and yedQ and activates their expression, thus inhibiting motility and promoting exopolysaccharide (EPS) production and biofilm formation. Consistent with previous findings that Cra plays a role in transcriptional regulation in response to carbon source availability, the activating effects of Cra were much more pronounced when LTYR-11Z was grown within a gluconeogenic environment than when it was grown within a glycolytic environment. We further demonstrate that the ability of LTYR-11Z to colonize wheat roots is modulated by the availability of carbon sources. Altogether, these results uncover a novel strategy utilized by LTYR-11Z to achieve host colonization in response to carbon nutrition in the environment, in which Cra bridges a connection between carbon metabolism and colonization capacity of LTYR-11Z. IMPORTANCE Rapid and appropriate response to environmental signals is crucial for bacteria to adapt to competitive environments and to establish interactions with their hosts. Efficient colonization and persistence within the host are controlled by various regulatory factors that respond to specific environmental cues. The most common is nutrient availability. In this work, we unraveled the pivotal role of Cra in regulation of colonization ability of Pantoea alhagi LTYR-11Z in response to carbon source availability. Moreover, we identified three novel members of the Cra regulon involved in EPS synthesis, regulation of flagellar biosynthesis, and synthesis of c-di-GMP and propose a working model to explain the Cra-mediated regulatory mechanism that links carbon metabolism to host colonization. This study elucidates the regulatory role of Cra in bacterial attachment and colonization of plants, which raises the possibility of extending our studies to other bacteria associated with plant and human health.

A Method of Profiling Microbial Communities Based on a Most-Probable-Number Assay That Uses BIOLOG Plates and Multiple Sole Carbon Sources

1999 ◽  
Vol 65 (10) ◽  
pp. 4419-4424 ◽  
Author(s):  
Masashi Gamo ◽  
Tadashi Shoji
Keyword(s):  
Bacterial Communities ◽  
Carbon Sources ◽  
High Rate ◽  
Most Probable Number ◽  
Probable Number ◽  
New Approach ◽  
Mixing Ratios ◽  
Color Development ◽  
Assay Procedure ◽  
Pure Cultures

ABSTRACT A new approach to the community-level BIOLOG assay was proposed. This assay, which we call the BIOLOG-MPN assay, is a most-probable-number (MPN) assay that uses BIOLOG plates and multiple sole carbon sources, and the profiles obtained by this assay consist of MPNs estimated for the substrates in the BIOLOG plates. In order to demonstrate the performance of the BIOLOG-MPN assay, it was applied to pure cultures, model bacterial communities that contain two strains in different ratios, and microbial community samples. MPN estimation using BIOLOG plates worked well for the substrates on which utilizers can grow at a sufficiently high rate for color development under the conditions of the assay procedure. Furthermore, the results obtained using model communities showed that the MPNs obtained reflected the mixing ratios of pure cultures in the model communities. The profiles obtained using model communities and community samples were differentiated properly by statistical analyses. The results suggest that the BIOLOG-MPN assay is a promising procedure for obtaining a quantitative picture of the community structure.

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