Yeast growth potential and COD reduction in waste water from ergot alkaloid production

The screening of yeast cultures for their growth and chemical oxygen demand (COD) reduction capability in waste water from ergot alkaloid production w as evaluated. Efficient COD reduction in filtered waste water was the main criterion for the screening of 27 previously selected yeast strains fi om t he Culture Collection of Industrial Microorganisms (ZIM), Ljubljana, Sloven ia. Sixteen 16 isolated yeast strains originating from the waste wafer were also included. The results showed that 3 yeasts from the ZIM Culture Colle ction reduced COD by over 60 % and 10 out of 16 isolated yeast strains redu ced 68 to 74 % of the initial COD value within 72 hours. Final screening am ong yeast cultures was performed in a 2 L airlift bioreactor. It was found that 10 yeast isolates, identified as Pichia anomala strains could be used for reducing the COD load of the waste water from ergot alkaloid production . One of the isolated yeasts, ZIM 419, was further cultivated in a 3.5 L st irred bioreactor and 81 % reduction of the initial COD was achieved within 37 hours.