Continuous decolorization of molasses waste water using immobilized Lactobacillus hilgardii cells.

Abstract

The continuous decolorization of molasses waste water (MWW) by immobilized cells of Lactobacillus hilgardii W-NS was studied. The immobilized cells showed the maximal decolorization yield in the presence of 1% glucose with a medium pH of 5.0 at 45°C. On successive decolorization of MWW, with recycling of the immobilized cells, more than 90% of the maximal decolorization yield was maintained for one month when 0.05% peptone was added to MWW. In contrast, on continuous decolorization in a column type reactor, a sufficient decolorization yield could not be maintained, the decolorization yield dropping to half the maximal level during operation for 5 days. But the feeding of MWW adjusted to the pH of 7.3, compared with the maximal pH value (5.0), slowed down the decrease in the decolorization yield.