scholarly journals ENZIMAS MICROBIANA: POTENCIAL BIOTECNOLÓGICO E EFEITOS MODULATÓRIOS EM RUMINANTES

2017 ◽  
Vol 13 (Especial 2) ◽  
pp. 164-173
Author(s):  
Flávia Oliveira Abrão ◽  
Cláudio Eduardo Silva Freitas ◽  
Eduardo Robson Duarte ◽  
Moisés Sena Pessoa ◽  
Luis Henrique Curcino Batista ◽  
...  
Keyword(s):  
Cell Wall ◽  
Gastrointestinal Tract ◽  
Enzymatic Activity ◽  
Microbial Diversity ◽  
Broad Spectrum ◽  
Plant Cell Wall ◽  
Animal Nutrition ◽  
Microbial Enzymes ◽  
Enzyme Modulation ◽  
Production Animals

The objective of this review was to survey the main microbial species producing enzymes involved in the degradation of compounds such as cellulose, hemicellulose and lignin. Most of the microorganisms isolated from soil, waste and compost material are capable of producing a broad spectrum of degrading enzymes from the plant cell wall. This enzymatic activity is essential for the fermentation of carbohydrates in the ruminal environment, since ruminants are not able to degrade these polymers, thus establishing a symbiosis relationship between these animals and the autochthonous microbiota of the gastrointestinal tract. However, microbial enzymes have not only been receiving attention in animal nutrition, more and more these have been explored by the industry as biotechnological possibilities, such as the production of ethanol. It is observed a microbial diversity in the rumen, and variations in the production of enzymes. Further studies are needed to elucidate the mechanisms of enzyme modulation in the rumen of production animals, in order to obtain an increase in zootechnical indexes and a higher digestibility of the fiber

scholarly journals Thermophilic Degradation of Hemicellulose, a Critical Feedstock in the Production of Bioenergy and Other Value-Added Products

2020 ◽  
Vol 86 (7) ◽  
Author(s):  
Isaac Cann ◽  
Gabriel V. Pereira ◽  
Ahmed M. Abdel-Hamid ◽  
Heejin Kim ◽  
Daniel Wefers ◽  
...  
Keyword(s):  
Cell Wall ◽  
Plant Cell ◽  
Plant Cell Wall ◽  
Plant Biomass ◽  
Animal Feed ◽  
Value Added ◽  
Building Blocks ◽  
Economic Feasibility ◽  
Renewable Fuels ◽  
Microbial Enzymes

ABSTRACT Renewable fuels have gained importance as the world moves toward diversifying its energy portfolio. A critical step in the biomass-to-bioenergy initiative is deconstruction of plant cell wall polysaccharides to their unit sugars for subsequent fermentation to fuels. To acquire carbon and energy for their metabolic processes, diverse microorganisms have evolved genes encoding enzymes that depolymerize polysaccharides to their carbon/energy-rich building blocks. The microbial enzymes mostly target the energy present in cellulose, hemicellulose, and pectin, three major forms of energy storage in plants. In the effort to develop bioenergy as an alternative to fossil fuel, a common strategy is to harness microbial enzymes to hydrolyze cellulose to glucose for fermentation to fuels. However, the conversion of plant biomass to renewable fuels will require both cellulose and hemicellulose, the two largest components of the plant cell wall, as feedstock to improve economic feasibility. Here, we explore the enzymes and strategies evolved by two well-studied bacteria to depolymerize the hemicelluloses xylan/arabinoxylan and mannan. The sets of enzymes, in addition to their applications in biofuels and value-added chemical production, have utility in animal feed enzymes, a rapidly developing industry with potential to minimize adverse impacts of animal agriculture on the environment.

scholarly journals Fermentation and subsequent disposition of 14C-labelled plant cell wall material in the rat

1993 ◽  
Vol 69 (1) ◽  
pp. 189-197 ◽  
Author(s):  
D. F. Gray ◽  
M. A. Eastwood ◽  
W. G. Brydon ◽  
S. C. Fry
Keyword(s):  
Cell Wall ◽  
Gastrointestinal Tract ◽  
Plant Cell ◽  
Plant Cell Wall ◽  
Spinacia Oleracea ◽  
Wall Material ◽  
Fermentation Products ◽  
Bacterial Fermentation ◽  
Cell Wall Preparation

A 14C-Iabelled plant cell wall preparation (I4C-PCW) produced from spinach (Spinacia oleracea L.) cell culture exhibits uniform labelling of the major polysaccharide groups (%): pectins 53, hemicellulose 13, cellulose 21, starch 3. This 14C-PCW preparation has been used in rat studies as a marker for plant cell wall metabolism. Metabolism of the 14C-PCW occurred largely over the first 24 h. This was due to fermentation in the caecum. The pectic fraction of the plant cell walls was degraded completely in the rat gastrointestinal tract, but some [14C-]cellulose was still detected after 24 h in the colon. Of the 14C,22% was recovered in the host liver, adipose tissue and skin, 26% excreted as 14CO2 and up to 18%was excreted in the faeces. There was no urinary excretion of 14C. In vitro fermentation using a caecal inocuium showed reduced 14CO2 production, 12% compared with 26% in the intact rat. 14C-PCW is auseful marker to investigate the fate of plant cell wall materials in the gastrointestinal tract. These studies show both bacterial fermentation of the 14C-PCW and host metabolism of the 14C-labelled fermentation products.

scholarly journals Toward Broad Spectrum DHFR inhibitors Targeting Trimethoprim Resistant Enzymes Identified in Clinical Isolates of Methicillin-Resistant Staphylococcus aureus

2019 ◽  
Author(s):  
Stephanie M. Reeve ◽  
Debjani Si ◽  
Jolanta Krucinska ◽  
Yongzhao Yan ◽  
Kishore Viswanathan ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Enzymatic Activity ◽  
Dihydrofolate Reductase ◽  
Molecular Interactions ◽  
Broad Spectrum ◽  
Active Sites ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Cellular Activity ◽  
Dhfr Inhibitors

AbstractThe spread of plasmid borne resistance enzymes in clinical Staphylococcus aureus isolates is rendering trimethoprim and iclaprim, both inhibitors of dihydrofolate reductase (DHFR), ineffective. Continued exploitation of these targets will require compounds that can broadly inhibit these resistance-confering isoforms. Using a structure-based approach, we have developed a novel class of ionized non-classical antifolates (INCAs) that capture the molecular interactions that have been exclusive to classical antifolates. These modifications allow for a greatly expanded spectrum of activity across these pathogenic DHFR isoforms, while maintaining the ability to penetrate the bacterial cell wall. Using biochemical, structural and computational methods, we are able to optimize these inhibitors to the conserved active sites of the endogenous and trimethoprim resistant DHFR enzymes. Here, we report a series of INCA compounds that exhibit low nanomolar enzymatic activity and potent cellular activity with human selectivity against a panel of clinically relevant TMPR MRSA isolates.

scholarly journals Uncovering the Cultivable Microbial Diversity of Costa Rican Beetles and Its Ability to Break Down Plant Cell Wall Components

PLoS ONE ◽  
2014 ◽  
Vol 9 (11) ◽  
pp. e113303 ◽  
Author(s):  
Gabriel Vargas-Asensio ◽  
Adrian Pinto-Tomas ◽  
Beatriz Rivera ◽  
Myriam Hernandez ◽  
Carlos Hernandez ◽  
...  
Keyword(s):  
Cell Wall ◽  
Microbial Diversity ◽  
Plant Cell ◽  
Plant Cell Wall ◽  
Costa Rican ◽  
Cell Wall Components ◽  
Wall Components

In vitro and in vivo polysaccharides assembly: ultrastructural and cytochemical study of growing plant cell wall components.

1978 ◽  
Vol 36 (2) ◽  
pp. 434-435
Author(s):  
D. Reis ◽  
B. Vian ◽  
J. C. Roland
Keyword(s):  
Cell Wall ◽  
Self Assembly ◽  
Plant Cell Wall ◽  
Higher Plants ◽  
Three Dimensional ◽  
Cytochemical Study ◽  
Wall Components

Wall morphogenesis in higher plants is a problem still open to controversy. Until now the possibility of a transmembrane control and the involvement of microtubules were mostly envisaged. Self-assembly processes have been observed in the case of walls of Chlamydomonas and bacteria. Spontaneous gelling interactions between xanthan and galactomannan from Ceratonia have been analyzed very recently. The present work provides indications that some processes of spontaneous aggregation could occur in higher plants during the formation and expansion of cell wall.Observations were performed on hypocotyl of mung bean (Phaseolus aureus) for which growth characteristics and wall composition have been previously defined.In situ, the walls of actively growing cells (primary walls) show an ordered three-dimensional organization (fig. 1). The wall is typically polylamellate with multifibrillar layers alternately transverse and longitudinal. Between these layers intermediate strata exist in which the orientation of microfibrils progressively rotates. Thus a progressive change in the morphogenetic activity occurs.

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