Gluconacetobacter hansenii UAC09-mediated transformation of polyphenols and pectin of coffee cherry husk extract

Gluconacetobacter, a bacterial cellulose (BC)-producing organism, has ability to utilise pectin and phenolic compounds. The extract of coffee cherry husk (CCH), a high pectin- and polyphenol-containing agro waste was used in the study. Production of endo- and exo-polygalacturonase, polyphenol oxidase and tannase was observed during fermentation. Co-utilisation of glucose and galacturonic acid was observed. Accumulation of rhamnose, arabinose and galactose indicated the breakdown of pectin. Among the phenolic acids, benzoic acid derivatives were found to be degraded faster than cinnamic acid derivatives. Degradation of tannic acid was more pronounced among the bound forms than free forms in the culture broth. In BC, accumulation of free tannic. gentisic and coumaric acids was observed during the 2nd week of fermentation. The present work indicates the ability of the organism to produce BC by the utilisation of agro waste like CCH. (C) 2011 Elsevier Ltd. All rights reserved.