A method for treating contaminated water or other contaminated media has been developed. Bioremediation enhancing agents (BEAs) such as yeast metabolites (YM) and other yeast derived products are used to facilitate microbial treatment of the contaminated material. Polysaccharides are also an effective BEA when used alone or in combination with the yeast derived products. The BEAs may work with microbes and electron donors to improve the rate of contaminant degradation and to increase the efficiency of electron donor utilization. A number of electron donors are also disclosed.