Abstract

D-ARABINOSE INDUCED GROWTH PATTERNS OF SOME GRAM POSITIVE AND GRAM NEGATIVE BACTERIA

Soumen Roychowdhury, Sayak Nanda, Arijit Pani, Sweta Manna,
Yogesh B. J. and Satadal Das*

Abstract

D-Arabinose is usually absent in natural habitat and thus not usually metabolized by bacteria. However, it was found that mutants of bacteria can utilize it as a sole source of carbon as well as energy, particularly when there is mutation of L-fucose pathway. Usually bacteria degrade L-fucose to L-lactaldehyde and dihydroxyacetone phosphate by the enzyme L-fucose permease and some other enzymes like L-fucose isomerase, L-fuculokinase and L-fuculose-1-phosphate aldolase. In mutants there is formation of D-glycoaldehyde instead of L-lactaldehyde. In this study we aimed to find out patterns of growths of some gram positive and gram negative bacteria in different concentrations of D-arabinose in microtitre plates by observing optical density changes at different incubation periods in an ELISA reader at 620 nm. It was found that a concentration of D-arabinose of 2.1 mg/mL appeared to be optimum for almost all types of tested bacteria. Utilization of D-arabinose by E. coli was less than the other tested bacteria like Staphylococcus, Salmonella and Shigella spp. There is no significant difference between gram positive and gram negative bacteria for utilization of D-arabinose. The growth was found maximum at 4 hours of incubation at 37OC and in all cases the growth declines with lysis of bacteria in 24 hours. This study thus indicates that the bacteria recognize Darabinose as inducer for their growth on D-arabinose.

Keywords: D-arabinose, bacteria, L-fucose.