STUDIES ON THE AEROBIC CARBOHYDRATE METABOLISM OF LEUCONOSTOC MESENTEROIDES

FERMENTATION OF GLUCOSE-C 14 AND XYLOSE-C 14 BY VARIOUS STRAINS OF LEUCONOSTOC MESENTEROIDES

“…The fermentation of glucose by the five strains of L. mesenteroides proceeded smoothly to completion with the addition of the theoretical amount of NaOH necessary to neutralize 1 mole of acid produced per mole of added substrate. The products of the anaerobic fermentations, carbon dioxide, ethanol and lactic acid, are the same for all strains as demonstrated in table 1, and provide support for the suggestion by Johnson and McCleskey (1957) for the similarity of their metabolic pathways under anaerobic conditions. In some of the fermentations a small amount of acetic acid was formed, perhaps because of incomplete removal of oxygen.…”

FURTHER STUDIES ON THE AEROBIC METABOLISM OF LEUCONOSTOC MESENTEROIDES

“…Resting cells of L. mesenteroides used approximately y mole of oxygen per mole of gluconate and produced approximately equimolar quantities of C02, lactate and acetate (table 1). A comparison of these results with those reported for the aerobic breakdown of glucose (Johnson and McCleskey, 1957) shows that only half as much oxygen is required for gluconate oxidation as for glucose. Thus, the oxidation of glucose to gluconate is one of the steps at which oxygen serves as final acceptor for substrate hydrogen.…”

Responses of lactic acid bacteria to oxygen

“…mesenteroides (NADH oxidase-positive) growing aerobically on glucose is approximately double that obtained during anaerobic growth [16]. In addition, growth rates on glucose in the presence of O~ are much faster than in its absence [16,56], indicating that the rate of ATP formation from sugars is a growth-rate-limiting step in these bacteria. The RNA/DNA and RNA/protein ratios of Leuc.…”

“…The end-products of anaerobic glucose fermentation by leuconostocs are mainly lactate, ethanol and CO2, but acetate is largely substituted for ethanol during aerobic growth ( Fig. 1; [ 16,[54][55][56][57][58]). Strains which are missing NADH oxidase (occur- ring naturally or constructed by mutation) form lactate, ethanol and CO 2 in the presence or absence of 02 [16].…”