Co-culturing microalgae with endophytic bacteria increases nutrient removal efficiency for biogas purification. (October 2020)

• Record Type: Journal Article
• Authors: Xu, Ming; Xue, Zhaoxia; Sun, Shiqing; Zhao, Chunzhi; Liu, Jinhua; Liu, Juan; Zhao, Yongjun
• Is Part Of: Bioresource technology. Volume 314(2020)
• Publication Date: 2020-10
• Subjects: Carbonic anhydrase activity -- Chlorella vulgaris -- CO2 removal -- Dry weight -- Photosynthetic performance; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2020.123766
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: Two bacterial strains of different genera were isolated from Chlorella vulgaris. Bacillus strain improved algae growth, photosynthesis, and nutrient removal. Optimal co-culturing conditions were 7 days and 10:1 bacteria-to-microalgae ratio. Bacteria and microalgae consortium efficiently purified biogas and biogas slurry. Abstract: Endophytic bacteria were isolated from Chlorella vulgaris and co-cultured with its host microalgae to determine whether this symbiotic system is suitable for purifying biogas and biogas slurry. Results showed that endophytic bacteria S395-1 and S395-2 belonged to different genera. Both strains promoted microalgae growth while improving photosynthetic performance, carbonic anhydrase activity, nutrient removal efficiency, and CO2 fixation. The optimal bacteria (S395-2)-to-microalgae ratio and co-culture duration were 10:1 and 7 days. Under this condition, the growth rate and carbonic anhydrase activity were 0.196 ± 0.06 d -1 and 31.24 ± 0.28 EU/cell, respectively. The symbiotic system had removal efficiencies of 88.29 ± 5.03%, 88.31 ± 4.29%, 88.21 ± 4.51%, and 68.13 ± 1.69% for chemical oxygen demand, nitrogen, phosphorus, and CO2, respectively. These results will provide a framework for constructing a microalgal-bacterial consortium that can improve wastewater treatment and enhance biogas quality.