Harvesting and contamination control of microalgae Chlorella ellipsoidea using the bio-polymeric flocculant α-poly-l-lysine

• Published in: Bioresource technology 2018-02, Vol.249, p.206-211
• Main Authors: Noh, Won, Kim, Jungmin, Lee, Sang-jun, Ryu, Byung-Gon, Kang, Chang-min
• Format: Article
• Language: English
• Subjects: antimicrobial properties; Biomass; biopolymers; Chlorella; Chlorella ellipsoidea; Contamination reduction; economic feasibility; flocculants; Flocculation; Harvesting; Lysine; Microalgae; moieties; storage quality; technology; α-poly-l-lysine
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2017.09.157

[Display omitted] •Chlorella ellipsoidea was efficiently recovered from culture broth using α-PLL.•Efficient dose- and time-dependent harvesting was achieved with increasing α-PLL MW.•Biomass harvested by α-PLL showed no biological contamination. Microalgae have been extensively studied for the production of various products. However, to date, microalgal biomass has not become economically feasible, mainly due to different issues such as contamination from various sources that occurs during downstream processes, and which leads to low quality biomass with limited application. In this study, to overcome contamination by flocculants and other microorganisms, the cationic biopolymer α-Poly-l-lysine (α-PLL) was applied. The cationic amine moiety and polymeric chain of α-PLL rendered microalgal harvesting efficient. With increasing α-PLL chain length, efficient dose- and time-dependent harvesting was achieved. In addition to efficient flocculation performance, biomass harvested using α-PLL showed suppressed biological contamination through the inherent antimicrobial activity of α-PLL. Thus, it is possible to upgrade the quality and storability of produced microalgal biomass using α-PLL-induced flocculation.