Abstract
Due to the high organic compounds and high salinity of fishmeal wastewater (FW), it was firstly used as a novel medium to produce microbial lipid in this paper. Fermentation of FW without any additives adding showed that the broth was appropriate for the growth of strain Lipomyces starkeyi HL; however, production of 5.34 g l−1 of biomass containing 20.8% of lipid was not satisfied. In order to enhance the accumulation of lipid and cell growth, FW was supplemented with various concentrations of glucose; meanwhile, the influence of initial pH was investigated. Biomass and lipid yield on FW were markedly affected by glucose concentration and initial pH. The addition of 20 g l−1 glucose at initial pH 4.0 got the best results: 17.6 g l−1 of biomass, 2.7 g l−1 of lipid yield, 91.2% of protein removal and 43.4% of the chemical oxygen demand removal. The variation of fatty acid composition upon time course in the cellular lipid on FW or a mixture of glucose and FW was further studied.
Acknowledgements
The authors gratefully acknowledge the financial support from Rongcheng Mingyuan Aquatic Food Co., Ltd in Weihai of Shandong Province, China. We also thank Dr. Hui-Jun Xie, Dr. Li Li and Guang-Bin Yin for their valuable advice and Yu-Mei Liu for her help in the laboratory.