Abstract
The distillery wastewaters lead to multiple environmental concerns due to release in large volume of pollutants in water-bodies.
In the present study, microbes tolerant to 10-50%, v/v of distillery spent wash (DSW) and decolorization capacity were explored
for decontamination. Total 32 microbes from various eco-habitats and depositary were examined to degrade DSW, initially at
10% and successively to 25 and 50%. Of these, 3 thermotolerant Pichia sp. viz. Y4, Y16 and D1C and an isolate SS3 identified
as Bacillus firmus were selected for growth in 25 and 50% MS-DSW at 120 rpm, 30oC, pH 6.5 (bacteria) and 40oC, pH 4.5
(thermotolerant yeasts), demonstrating catabolism of DSW as carbon source. The decolorization efficiencies of Pichia sp. Y4,
Y16 and D1C were 36, 32 and 34%, respectively, while B. firmus showed 36%. The gradual decline in decolorization of 50%
DSW by yeast and 25% DSW by SS3 occurred possibly due to loss of cell viability and increase in pH to 9.0. The yeasts
decreased BOD and COD in the range of 55-72 and 65-80%, respectively, while B. firmus SS3 showed reduction in COD and
BOD to 67 and 57%, respectively after 96 h. The HPLC analysis of treated effluent further confirmed the degradation of
melanoidin.