Physiological and fermentation properties of Bacillus coagulans and a mutant lacking fermentative lactate dehydrogenase activity.
Summary of "Physiological and fermentation properties of Bacillus coagulans and a mutant lacking fermentative lactate dehydrogenase activity."
Bacillus coagulans, a sporogenic lactic acid bacterium, grows optimally at 50-55 degrees C and produces lactic acid as the primary fermentation product from both hexoses and pentoses. The amount of fungal cellulases required for simultaneous saccharification and fermentation (SSF) at 55 degrees C was previously reported to be three to four times lower than for SSF at the optimum growth temperature for Saccharomyces cerevisiae of 35 degrees C. An ethanologenic B. coagulans is expected to lower the cellulase loading and production cost of cellulosic ethanol due to SSF at 55 degrees C. As a first step towards developing B. coagulans as an ethanologenic microbial biocatalyst, activity of the primary fermentation enzyme
-lactate dehydrogenase was removed by mutation (strain Suy27). Strain Suy27 produced ethanol as the main fermentation product from glucose during growth at pH 7.0 (0.33 g ethanol per g glucose fermented). Pyruvate dehydrogenase (PDH) and alcohol dehydrogenase (ADH) acting in series contributed to about 55% of the ethanol produced by this mutant while pyruvate formate lyase and ADH were responsible for the remainder. Due to the absence of PDH activity in B. coagulans during fermentative growth at pH 5.0, the l-ldh mutant failed to grow anaerobically at pH 5.0. Strain Suy27-13, a derivative of the l-ldh mutant strain Suy27, that produced PDH activity during anaerobic growth at pH 5.0 grew at this pH and also produced ethanol as the fermentation product (0.39 g per g glucose). These results show that construction of an ethanologenic B. coagulans requires optimal expression of PDH activity in addition to the removal of the LDH activity to support growth and ethanol production.
Department of Microbiology and Cell Science, University of Florida, Box 110700, Gainesville, FL, 32611, USA.
This article was published in the following journal.
Name: Journal of industrial microbiology & biotechnology
- PubMed Source: http://www.ncbi.nlm.nih.gov/pubmed/20677017
- DOI: http://dx.doi.org/10.1007/s10295-010-0788-4
Medical and Biotech [MESH] Definitions
Dental Physiological Phenomena
Physiological processes and properties of the DENTITION.
Bacterial Physiological Phenomena
Physiological processes and properties of BACTERIA.
Bacteriocins elaborated by mutant strains of Bacillus megaterium. They are protein or protein-lipopolysaccharide complexes lethal to other strains of the same species.
Plant Physiological Phenomena
The physiological processes, properties, and states characteristic of plants.
Reproductive Physiological Phenomena
Physiological processes, factors, properties and characteristics pertaining to REPRODUCTION.
Xylose is the major pentose and the second most abundant sugar in lignocellulosic feedstock. Its efficient utilization is regarded as a technical barrier to the commercial production of bulk chemicals...
Lactic acid is used as an additive in foods, pharmaceuticals, and cosmetics, and is also an industrial chemical. Optically pure lactic acid is increasingly used as a renewable bio-based product to rep...
Bacillus coagulans XZL4 is an efficient pentose-utilizing producer of important platform compounds, such as l-lactic acid, 2,3-butanediol, and acetoin. Here we present a 2.8-Mb assembly of its genome....
Acidothermophilic bacteria like Alicyclobacillus acidoterrestris and Bacillus coagulans can cause spoilage of heat-processed acidic foods because they form spores with very high heat resistance and ca...
Bakers' yeast producing companies grow cells under respiratory conditions, at a very high growth rate. Some desirable properties of bakers' yeast may be altered if fermentation rather than respiration...
An important group of protein-bound uremic retention solutes originate from protein fermentation in the colon. P-cresol is a putrefaction metabolite of tyrosine. Indole is generated by fer...
The purpose of this study is to determine the effect of supplement combined various probiotics and fermentation products on body mass index, body fat mass, abdominal circumference, viscera...
Primary objective: - To demonstrate the efficacy of a Bacillus clausii probiotic strain compared to placebo in children suffering from acute diarrhoea and treated for 7 days....
Protein-bound uremic retention solutes are increasingly recognized to play a role in the pathophysiology of the uremic syndrome. Numerous in vitro findings are indicative for their implica...
Several milk proteins are precursors of peptides, released during fermentation, which possess various biochemical and physiological properties. Among them, some peptides have been reported...