The Journal of General and Applied Microbiology
Online ISSN : 1349-8037
Print ISSN : 0022-1260
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Strain improvement studies on Microbacterium foliorum GA2 for production of α-amylase in solid state fermentation: Biochemical characteristics and wash performance analysis at low temperatures
RoohiMohammed Kuddus
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2017 Volume 63 Issue 6 Pages 347-354


Microbacterium foliorum GA2, an alkali-tolerant bacterium, was randomly mutated using UV radiation and sodium azide to obtain a mutant with a higher cold-active extracellular amylolytic activity. A mutant, designated as MFSD20, was selected owing to its higher amylase activity at 20°C. Under optimized conditions, amylase production was achieved best with raw banana peels (5000 units) in solid-state fermentation (SSF). The enzyme was purified by salt precipitation and chromatographic methods and afterwards characterized biochemically. The purified enzyme showed maximal activity at temperatures between 15–25°C and at pH 8.0. Interestingly, this mutant biocatalyst (MFSD20) displays higher catalytic activity under conditions of low temperature (4°C) and high pH (10.0), in the presence of SDS (0.1 and 1%), and exhibited 85% and 50% requirement of divalent metallic ions Ca2+ and Mg2+, respectively. This mutant enzyme extract in combination with “Wheel detergent” was highly effective in the removal of tomato sauce and chocolate stains from white cotton fabric was demonstrated by ~50% additional reflectance compared with detergent alone, in a wash performance analysis at 20 ± 2°C. The features shown by mutant M. foliorum GA2 make it a promising candidate for industrial applications involving starch degradation at low temperatures.

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© 2017, Applied Microbiology, Molecular and Cellular Biosciences Research Foundation
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