Enhanced microalgal biomass and lipid production from a consortium of indigenous microalgae and bacteria present in municipal wastewater under gradually mixotrophic culture conditions

• Published in: Bioresource technology Vol. 228; pp. 290 - 297
• Main Authors: Cho, Hyun Uk, Kim, Young Mo, Park, Jong Moon
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.03.2017
• Subjects: Bacteria - metabolism; Batch Cell Culture Techniques - methods; Biomass; Cell Culture Techniques - methods; Chlorella - growth & development; Chlorella - metabolism; Denaturing Gradient Gel Electrophoresis; Fatty acids; Fatty Acids, Volatile - analysis; Fermentation; Lipids - biosynthesis; Microalgae - metabolism; Microalgal biomass; Microalgal-bacterial consortium; Mixotrophic culture; RNA, Ribosomal, 16S - genetics; Sewage - microbiology; Volatile fatty acids (VFAs); Waste Water - microbiology; Microalgal biomass; Volatile fatty acids (VFAs); Microalgal-bacterial consortium; Fatty acids; Mixotrophic culture
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2016.12.094

[Display omitted] •An autochthonous microalgal-bacterial consortium was cultivated mixotrophically.•The link between reactor performance and microbial community changes was identified.•Stepwise increase in VFAs concentration enhanced algal biomass and lipid production.•VFAs produced from sewage sludge were efficiently used as organic carbon sources.•The addition of VFAs benefited enhanced nitrogen and phosphate removals. The goal of this study was to investigate the influences of gradually mixotrophic culture conditions on microalgal biomass and lipid production by a consortium of indigenous microalgae and bacteria present in raw municipal wastewater. Lab-scale photobioreactors containing the consortium were operated in repeated batch mode. Initial cultivation (phase I) was performed using only the municipal wastewater, then 10% and 25% of the reactor volumes were replaced with the effluent from a sewage sludge fermentation system producing volatile fatty acids (SSFV) at the beginnings of phase II and phase III, respectively. The highest biomass productivity (117.1±2.7mg/L/d) was attained during phase II, but the lipid productivity (17.2±0.2mg/L/d) was attained during phase III. The increase in the effluent from the SSFV influenced microalgal diversity with a preference for Chlorella sp., but bacterial diversity increased significantly during phase III.