Microbial xylitol production

Xylitol is pentahydroxy sugar alcohol, existing in very trace amount in fruits and vegetables, and finds varied application in industries like food, pharmaceuticals, confectionaries, etc. and is of prime importance to health. Owing to its trace occurrence in nature and considerable increase in market demand that exceeds availability, alternate production through biotechnological and chemical approach is in process. Biochemical production involves substrates like lignocellulosic biomasses and industrial effluents and is an eco-friendly process with high dependency on physico-chemical parameters. Although the chemical processes are faster, high yielding and economical, they have a great limitation as usage of toxic chemicals and thus need to be regulated and replaced by an environment friendly approach. Microbes play a major role in xylitol production through a biotechnological process towards the development of a sustainable system. Major microbes working on assimilation of xylose for production of xylitol include Candida tropicalis, Candida maltose, Bacillus subtilis, Debaromyces hansenii, etc. The present review reports all probable microbial xylitol production biochemical pathways encompassing diverse bioprocesses involved in uptake and conversion of xylose sugars from agricultural residues and industrial effluents. A comprehensive report on xylitol occurrence and biotechnological production processes with varied substrates has been encompassed. KEY POINTS: • Xylitol from agro-industrial waste • Microbial xylose assimilation.