Improving biomass and carbohydrate production of microalgae in the rotating cultivation system on natural carriers

• Published in: AMB Express 2023-04, Vol.13 (1), p.39-39, Article 39
• Main Authors: Mousavian, Zahra, Safavi, Maliheh, Salehirad, Alireza, Azizmohseni, Farzaneh, Hadizadeh, Mahnaz, Mirdamadi, Saeed
• Format: Article
• Language: English
• Subjects: Algae; Aquatic microorganisms; Attached microalgae cultivation; Attachment; Biofilms; Biomass; Biomass harvesting; Biomedical and Life Sciences; Biotechnology; Carbohydrates; Cell culture; Chemical properties; Contact angle; Cotton; Cultivation; Cyanobacteria; Exopolysaccharides; Extracellular matrix; Jute; Life Sciences; Microalgae exopolysaccharide; Microbial Genetics and Genomics; Microbiology; Natural carrier; Original; Original Article; Productivity; Rotation; Surface properties; Suspension culture; Water conservation
• ISSN: 2191-0855; 2191-0855
• DOI: 10.1186/s13568-023-01548-5

Biofilm-based algal technologies have gained popularity due to higher biomass productivity, efficient harvesting, and water-saving over suspended growth systems. A rotating attached system was designed to assess the biofilm-forming capacity of different isolated microalgal strains from the Persian Gulf. Four microalgal strains, including two Chlorella sp., one Picochlorum sp. and one filamentous cyanobacterium Desmonostoc sp. were cultivated on four carriers: jute, cotton, yarn and nylon. The carriers’ physicochemical surface characteristics and attachment effects, like contact angle, were investigated. The incorporated biomass and exopolysaccharides (EPS) content in the suspended and biofilm system was calculated and compared. The results showed that the cyanobacterium strain had the biofilm formation capability on both jute and cotton in the attached cultivation system. Under the same culture conditions, the biomass productivity on jute and cotton carriers was significantly higher (4.76 and 3.61 g m − 2 respectively) than the growth in aqueous suspension (1.19 g m − 2 d − 1 ). The greatest incorporated exopolysaccharides amount was observed on jute (43.62 ± 4.47%) and the lowest amount was obtained from the growth on positive charge yarn (18.62 ± 1.88%). This study showed that in comparison with planktonic growth, the colonization of cyanobacterial cells and subsequent production of extracellular matrix and biofilm formation can lead to increased biomass production. Keypoints  • Biofilm algal cultivation provides easy biomass harvesting by mechanical scraping • The physio-chemical properties of the carrier influenced the attachment of microalgae cells • The filamentous strain showed optimal attachment performance on jute and cotton respectively