PUL-Mediated Plant Cell Wall Polysaccharide Utilization in the Gut Bacteroidetes

Plant cell wall polysaccharides (PCWP) are abundantly present in the food of humans and feed of livestock. Mammalians by themselves cannot degrade PCWP but rather depend on microbes resident in the gut intestine for deconstruction. The dominant Bacteroidetes in the gut microbial community are such bacteria with PCWP-degrading ability. The polysaccharide utilization systems (PUL) responsible for PCWP degradation and utilization are a prominent feature of Bacteroidetes. In recent years, there have been tremendous efforts in elucidating how PULs assist Bacteroidetes to assimilate carbon and acquire energy from PCWP. Here, we will review the PUL-mediated plant cell wall polysaccharides utilization in the gut Bacteroidetes focusing on cellulose, xylan, mannan, and pectin utilization and discuss how the mechanisms can be exploited to modulate the gut microbiota.

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Hierarchical architecture of bacterial cellulose and composite plant cell wall polysaccharide hydrogels using small angle neutron scattering

Soft Matter ◽

10.1039/c5sm02085a ◽

2016 ◽

Vol 12 (5) ◽

pp. 1534-1549 ◽

Cited By ~ 34

Author(s):

Marta Martínez-Sanz ◽

Michael J. Gidley ◽

Elliot P. Gilbert

Keyword(s):

Cell Wall ◽

Bacterial Cellulose ◽

Plant Cell ◽

Small Angle Neutron Scattering ◽

Plant Cell Wall ◽

Solvent Accessibility ◽

Hierarchical Architecture ◽

Cell Wall Polysaccharide ◽

Cell Wall Polysaccharides ◽

Sans Data

SANS data of bacterial cellulose and its composites with plant cell wall polysaccharides can be described by a core–shell model which accounts for the distinct solvent accessibility to the ribbons' inner/outer regions.

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Metatranscriptomic Analyses of Plant Cell Wall Polysaccharide Degradation by Microorganisms in the Cow Rumen

Applied and Environmental Microbiology ◽

10.1128/aem.03682-14 ◽

2014 ◽

Vol 81 (4) ◽

pp. 1375-1386 ◽

Cited By ~ 87

Author(s):

Xin Dai ◽

Yan Tian ◽

Jinting Li ◽

Xiaoyun Su ◽

Xuewei Wang ◽

...

Keyword(s):

Cell Wall ◽

Plant Cell ◽

Plant Cell Wall ◽

Average Length ◽

Glycoside Hydrolases ◽

Carbohydrate Binding ◽

Cell Wall Polysaccharide ◽

Cell Wall Polysaccharides ◽

Content Type ◽

Carbohydrate Binding Modules

ABSTRACTThe bovine rumen represents a highly specialized bioreactor where plant cell wall polysaccharides (PCWPs) are efficiently deconstructed via numerous enzymes produced by resident microorganisms. Although a large number of fibrolytic genes from rumen microorganisms have been identified, it remains unclear how they are expressed in a coordinated manner to efficiently degrade PCWPs. In this study, we performed a metatranscriptomic analysis of the rumen microbiomes of adult Holstein cows fed a fiber diet and obtained a total of 1,107,083 high-quality non-rRNA reads with an average length of 483 nucleotides. Transcripts encoding glycoside hydrolases (GHs) and carbohydrate binding modules (CBMs) accounted for ∼1% and ∼0.1% of the total non-rRNAs, respectively. The majority (∼98%) of the putative cellulases belonged to four GH families (i.e., GH5, GH9, GH45, and GH48) and were primarily synthesized byRuminococcusandFibrobacter. Notably, transcripts for GH48 cellobiohydrolases were relatively abundant compared to the abundance of transcripts for other cellulases. Two-thirds of the putative hemicellulases were of the GH10, GH11, and GH26 types and were produced by members of the generaRuminococcus,Prevotella, andFibrobacter. Most (∼82%) predicted oligosaccharide-degrading enzymes were GH1, GH2, GH3, and GH43 proteins and were from a diverse group of microorganisms. Transcripts for CBM10 and dockerin, key components of the cellulosome, were also relatively abundant. Our results provide metatranscriptomic evidence in support of the notion that members of the generaRuminococcus,Fibrobacter, andPrevotellaare predominant PCWP degraders and point to the significant contribution of GH48 cellobiohydrolases and cellulosome-like structures to efficient PCWP degradation in the cow rumen.

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Aspergillus Enzymes Involved in Degradation of Plant Cell Wall Polysaccharides

Microbiology and Molecular Biology Reviews ◽

10.1128/mmbr.65.4.497-522.2001 ◽

2001 ◽

Vol 65 (4) ◽

pp. 497-522 ◽

Cited By ~ 584

Author(s):

Ronald P. de Vries ◽

Jaap Visser

Keyword(s):

Cell Wall ◽

Plant Cell ◽

Plant Cell Wall ◽

Current Knowledge ◽

Wide Spectrum ◽

Structural Characteristics ◽

Attractive Alternative ◽

Cell Wall Polysaccharide ◽

Cell Wall Polysaccharides ◽

Degrading Enzymes

SUMMARY Degradation of plant cell wall polysaccharides is of major importance in the food and feed, beverage, textile, and paper and pulp industries, as well as in several other industrial production processes. Enzymatic degradation of these polymers has received attention for many years and is becoming a more and more attractive alternative to chemical and mechanical processes. Over the past 15 years, much progress has been made in elucidating the structural characteristics of these polysaccharides and in characterizing the enzymes involved in their degradation and the genes of biotechnologically relevant microorganisms encoding these enzymes. The members of the fungal genus Aspergillus are commonly used for the production of polysaccharide-degrading enzymes. This genus produces a wide spectrum of cell wall-degrading enzymes, allowing not only complete degradation of the polysaccharides but also tailored modifications by using specific enzymes purified from these fungi. This review summarizes our current knowledge of the cell wall polysaccharide-degrading enzymes from aspergilli and the genes by which they are encoded.

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Plant Cell Wall Hydration and Plant Physiology: An Exploration of the Consequences of Direct Effects of Water Deficit on the Plant Cell Wall

Plants ◽

10.3390/plants10071263 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1263

Author(s):

David Stuart Thompson ◽

Azharul Islam

Keyword(s):

Cell Wall ◽

Water Content ◽

Bacterial Cellulose ◽

Plant Cell ◽

Cell Walls ◽

Plant Cell Wall ◽

Plant Cell Walls ◽

Cell Wall Polysaccharides ◽

Degree Of Hydration ◽

Cellulose Composites

The extensibility of synthetic polymers is routinely modulated by the addition of lower molecular weight spacing molecules known as plasticizers, and there is some evidence that water may have similar effects on plant cell walls. Furthermore, it appears that changes in wall hydration could affect wall behavior to a degree that seems likely to have physiological consequences at water potentials that many plants would experience under field conditions. Osmotica large enough to be excluded from plant cell walls and bacterial cellulose composites with other cell wall polysaccharides were used to alter their water content and to demonstrate that the relationship between water potential and degree of hydration of these materials is affected by their composition. Additionally, it was found that expansins facilitate rehydration of bacterial cellulose and cellulose composites and cause swelling of plant cell wall fragments in suspension and that these responses are also affected by polysaccharide composition. Given these observations, it seems probable that plant environmental responses include measures to regulate cell wall water content or mitigate the consequences of changes in wall hydration and that it may be possible to exploit such mechanisms to improve crop resilience.

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