Process optimization for the production of sugar for the bioethanol industry from Tapioca, a non-conventional source of starch

NK Aggarwal, Poonam Singh - Nee Nigam, D Singh, BS Yadav

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12 Citations (Scopus)


A commercial preparation of alpha-amylase, Biotempase, obtained from Biocon India Pvt. Ltd., and crude glucoamylase produced from Aspergillus sp. NA21 were used to hydrolyse tapioca powder, a non-conventional starchy substrate. Among various concentrations of starch (15-35%, dry weight/volume) tried for maximum liquefaction; slurry made with 25% substrate concentration proved optimal. An economical process of liquefaction was carried out using steam under pressure (0.2-0.3 bar, 104-105 degreesC) to liquefy a 25% slurry in just 45 min, contrary to a slower process carried out at 95 degreesC in a water bath. For liquefaction of starch a pH of 5.0 proved to be optimum. The dose of Biotempase as prescribed by the supplier could be reduced by 33% achieving the same degree of liquefaction, by addition of CaCl2 to the starch slurry at the concentration of 120 mg/l. The conditions for the saccharification of liquefied starch were optimized to be 60 degreesC and pH 5.0, producing 90% saccharification in 24 h. Supplementation of divalent ions Ca2+, Mg2+ and Zn2+ in the process of saccharification showed no effect. Finally glucose was found to be the main hydrolysis product in the saccharification of tapioca starch.
Original languageEnglish
Pages (from-to)783-787
JournalWorld Journal of Microbiology and Biotechnology
Issue number8
Publication statusPublished - Nov 2001


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