Insights into the glucose photometabolism by Rubrivivax benzoatilyticus JA2

Abstract

Anoxygenic phototrophic bacteria (APB) display phenomenal metabolic plasticity newlineleading to distinct phenotypes. They bloom under varying habitat using an array of newlineorganic/inorganic compounds as carbon sources/electron donors, yet their metabolic newlineadaptation to fluctuating carbon regime is largely unexplored and thus remains elusive. newlineFurther, hyperglycemic effect on macro-organisms (mostly animals, including humans) is newlinewidely investigated but the same on microorganisms is in its infancy and not elucidated newlineclearly hence, remains an open question. Thus, there is a requirement of robust investigation newlineto enhance our current knowledge of hyperglycemic effect on microorganisms. Present study newlineis an attempt to glean biological insights of adaptive strategies employed by an APB member, newlineRubrivivax benzoatilyticus, in response to the hyperglycemic effect. The study aimed at newlinedeciphering the bacterial adjustments at physiological, biochemical, metabolomic, proteomic newlineand genomic level in response to hyperglycemia. Our investigation highlights that carbon newlinesource, determining the metabolic fate of the cells, can reshape the energy dynamics. newlineRbx. benzoatilyticus displayed altered growth rates, reduction in cellular size and newlinephotobleaching along with hampered photosynthetic gadgetry under photoheterotrophic newlinegrowth on glucose, as compared with malate. The organism grows chemotrophically when newlineglucose is provided as an electron donor but a change in its life style i.e when forced to grow newlinephotoheterotrophically, it switched to a non-cultivable state. Fatty acid metabolism was newlinesignificantly influenced with a ten-fold increase in the ratio of saturated fatty acid: newlineunsaturated fatty acid content of the non-cultivable cells as compared with exponential phase newlineof glucose grown Rbx. benzoatilyticus cells, signifying membrane rigidity. newlineGC-MS based metabolic profiling followed by multivariate statistical analyses of newlinefootprint (exometabolome) revealed the marked variation in the metabolism of malate and newlineglucose grown cells. Metabolomes from differ