Biodegradation of dairy wastes using crude enzymatic extract of Yarrowia lipolytica ATCC 9773

Abstract

Effluents generated by the food industry have become a serious environmental concern. Bioremediation is a biological process developed as an alternative for the treatment of contaminated areas. In current research, the biodegradation of fat, Biochemical Oxygen Demand (BOD5), Chemical Oxygen Demand (COD) and total solids were evaluated in dairy waste employing enzymatic extract of Yarrowia lipolytica ATCC 9773 as biological agents. All the variables were determined following the specifications of the Standard Methods of the American Water Works Association. Enzymatic extract of Y. lipolytica at different concentrations (8, 12 and 16.0%) was used in a fermentative medium at two pHs (5.0 and 6.5) for 32 h. The highest percentages (%) of fat (82.88), BOD (43.32), COD (44.3) and total solids (13.58) removal were obtained using an inoculum concentration of 16% at pH 5.0 for 32 h of fermentation. These results may have industrial relevance for the reduction of contamination of industrial effluents with high levels of fat and other contaminants.