(723b) Microbial Ecological Evolution in the Bioaugmentation of Petroleum Contaminated Soil

The bioaugmentation of petroleum contaminated soil using Enterobacter cloacae was profiled from the development of microbial community, the total dehydrogenase activity, and the degradation kinetics of petroleum contaminants. The predominance of E. cloacae and an abrupt change in the microbial community after inoculation was illustrated by DGGE, in addition to a successive change in response to degradation of the petroleum contaminant. The degradation process of crude oil in the contaminated soil was monitored, and the overall degradation ratio determined after 56 days of treatment was increased from 44 to 56% in response to the application of wheat straw, as a representative lignin waste. The application of wheat straw also induced an increase in the total dehydrogenase activity from 0.50 to 0.79 and enriched microbial community, 130% for bacteria and 84% for fungi. The application of wheat straw facilitated the seeding and proliferation of E. cloacae as an inoculant and resulted in a substantially enriched microbial community that favors the degradation of petroleum contaminants.