engleski

Utilization of maltose in lactic acid production by Lactobacillus amylovorus DSM 20531T

Strains of species Lactobacillus amylovorus possess extracellular amylolytic activity that is essential for their accomodation in natural niches. In our comprehensive investigations strain Lactobacillus amylovorus DSM 20531T was employed for hydrolysis and fermentation of starch as sole carbon and energy source. HPLC analysis have shown that starch was degraded to maltose and maltodextrins, while glucose was not detected during the bioprocess. The aim of this work was to characterize the utilization of maltose for production of D-/L-lactic acid by L. amylovorus DSM 20531T at laboratory scale. Initial concentration of maltose was 20.0 g/L and fermentation was carried out at 40C. The maltose was not completely depleted from the medium over 24.0 h of the bioprocess and substrate to product conversion coefficient (YP/S) of only 0.87 g of D- and L-lactic acid (in equimolar amounts) per g of spent maltose was achieved. No other fermentation products were observed in explored experimental conditions, although this strain was reported to produce small amounts of acetate at low sugar concentration.

bioreactor experiments, Lactobacillus amylovorus, maltose metabolism

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