Metabolism of hexoses and pentoses by Cellulomonas uda under aerobic conditions and during fermentation

Abstract

MARSCHOUN, S., RAPP, P., and WAGNER, F. 1987. Metabolism of hexoses and pentoses by Cellulomonas uda under aerobic conditions and during fermentation. Can. J. Microbiol. 33: 1024-103 1. Cellulomonas uda utilized the constituent carbohydrates of cellulose and hemicellulose under aerobic conditions and during fermentation. Balances of fermentation of cellobiose, glucose, xylose, 1,-arabinose, mannose, galactose, fructose, and sucrose were determined. Products formed were ethanol, L-lactic acid, acetic acid, formic acid, and succinic acid. In contrast to acetic acid, a small amount of succinic acid was utilized under aerobic conditions but only together with glucose. Ethanol was not consumed either under aerobic conditions or during fermentation. The rate of both glucose uptake and lactic acid excretion during fermentation increased with increasing initial pH values of 7 to 9. The intracellular concentration of ethanol at the end of glucose fermentation was 20 times higher than that in the culture supernatant. Switching from aerobic to fermentation conditions increased specific activities of fructose-6-phosphate kinase and fructose-l,6-bisphosphate aldolase, both key enzymes of the fructose-1,6-bisphosphate pathway, whereas those of glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase, key enzymes of the pentose phosphate cycle, were not affected significantly. Of the enzymes involved in pyruvic acid metabolism, pyruvate formate lyase, L-lactate dehydrogenase, and alcohol dehydrogenase were demonstrated in cell-free extracts. Fructose-l,6-bisphosphate had an activating effect on L-lactate dehydrogenase. Alcohol dehydrogenase was inhibited competitively by high concentrations of ethanol and noncompetitively by NAD.MARSCHOUN, S., RAPP, P., et WAGNER, F. 1987. Metabolism of hexoses and pentoses by Cellulomonas uda under aerobic conditions and during fermentation. Can. J. Microbiol. 33 : 1024-103 1 . Le Cellulomonas uda utilise les constituants hydrocarbonCs de la cellulose et des hCmicelluloses, tant en condition aCrobique qu'en condition de fermentation. Les produits rCsultant des fermentations ont Ct C dCterminCs pour les substances suivantes: le cellobiose, le glucose, le xylose, le L-arabinose, le mannose, le galactose, le fructose et le sucrose. Les produits formCs furent: de l'Cthanol, de l'acide L-lactique, de l'acide acCtique, de I'acide formique et de l'acide succinique. Sous condition aerobique, l'acide succinique, contrairement it l'acide acCtique, a Ct C utilisC en petites quantitCs, mais seulement en conjonction avec du glucose. L'Cthanol n'a Ct C utilisC ni sous condition aCrobique ni sous condition de fermentation. Au cours des fermentations, les taux d'absorption de glucose et d'excrktion d'acide lactique ont augment6 en meme temps que les valeurs initiales de pH sont passkes de 7 it 9. La concentration d'Cthanol intracellulaire au terme des fermentations fut 20 fois supkrieure it celle des sumageants en culture. Le passage des conditions akrobiques it celles de fermentation s'est trad...

Aerobic and anaerobic cellulase production by Cellulomonas uda

“…These hydrolysis products were likely derived either from cellulase activity present in the 5 % (v/v) inoculum and/or resulted from extremely low constitutive production of cellulases. From an application perspective, our results demonstrate that C. uda is not a prospective cellulase producer under anaerobic conditions, although it metabolically behaves as a true facultative anaerobe on soluble carbon substrates (Marschoun et al 1987 ; Dermoun and Belaich 1988 ). Further studies are required to elucidate why C. uda only produces negligible cellulase activity (FPA, AVA and EGA) under anaerobic conditions, and whether this deficiency extends to other published cellulolytic species of Cellulomonas .…”

“…Although Cellulomonas sp. are known to use a variety of soluble substrates anaerobically, as well as to degrade cellulose aerobically (Clemmer and Tseng 1986 ; Dermoun and Belaich 1985 ; Haggett et al 1979 ; Marschoun et al 1987 ), anaerobic growth of these organisms on cellulosic compounds has been little investigated (Dermoun and Belaich 1988 ; Reguera and Leschine 2001 ).…”

Factors affecting accumulation and degradation of curdlan, trehalose and glycogen in cultures of Cellulomonas flavigena strain KU (ATCC 53703)

“…Part of the energy of the glycosidic bond of cellobiose is thus conserved in this reaction. The glucose-1-phosphate can be directly activated to nucleotide sugar for polysaccharide synthesis, UDP-Glc for EPS synthesis or ADP-Glc for glycogen synthesis, or it can be converted into glucose-6-phosphate, by the action of phosphoglucomutase, and enter the EMP or pentose phosphate pathways to produce energy (Marschoun et al 1987). Thus, by using cellobiose phosphorylase, one mole of ATP is saved in the phosphorylation of the two glucose moieties of cellobiose.…”

Deconstruction of plant biomass by a Cellulomonas strain isolated from an ultra-basic (lignin-stripping) spring

“…S5). Members of genus Cellulomonas in general, appear to be well-adapted to persisting under highly alkaline conditions (Marschoun et al 1987;Trujillo-Cabrera et al 2013).…”

“…Cellulomonas species have been shown to ferment a variety of carbohydrates to ethanol (Stackebrandt and Kandler 1980; Marschoun et al 1987;Poulsen et al 2016) and under anaerobic conditions to co-occur with other ethanol-producing microorganisms on decaying lignocellulosic substrates. The FA1 genome encodes homologs of three Zn-alcohol dehydrogenases (WP_046528611, WP_046530663, WP_046530044), one Fe-alcohol dehydrogenase (WP_046529978), and a bifunctional acetaldehyde-CoA/alcohol dehydrogenase (WP_052748132) that could potentially function in catabolism or production of ethanol.…”