Evaluation of the Growth and Biomass Production of Eight Commercially Important Microalgae Species Isolated from Lake Tana, Ethiopia

Abayneh Utalo; Ayalew Wondie; Masatoshi Kishi

Abstract

Microalgae are a diverse group of photosynthetic microorganisms that can be cultivated in a controlled condition for different economic and environmental applications. This study aimed to evaluate the growth and biomass productivity of some selected microalgae species isolated from Lake Tana (Ethiopia) in a laboratory suitable for mass cultivation. The study was conducted from February (2020) to January (2021). C-media was used for cultivation at an incubation condition of 2500 Lux (12 light: 12 dark) fluorescent light. Temperature controlling water bath which is adjusted at a temperature of 24°C was used for cultivation in the laboratory. Eight microalgae species were selected namely Stichococcus, Synechococcus, Scenedesmus, Scenedesmus armatus, Chlorella, Ankistrodusmus, Monoraphidium and Chlamydomonas species. The microalgae species showed a significant difference in specific growth rate (µ) as well as biomass productivity. Chlorella and Stichococcus species showed higher specific growth rates that are 0.182±0.03 and 0.153±0.04 day-1, respectively. Chlamydomonas and Synechococcus species showed the highest biomass production (1013±94 and 934±94 mgL-1) respectively. Chlorella, Synechococcus and Ankistrodusmus species showed the highest protein (43.6%), lipid (41.3%) and carbohydrate (47.1%) contents in their dry cell respectively. Thus, Chlorella species, Stichococcus species, Chlamydomonas, Ankistrodusmus and Synechococcus species were the most promising strains for mass cultivation in controlled conditions for different applications due to their ability to grow well in a liquid medium, high accumulation of protein, lipid and carbohydrates as well as ability to remain in suspension during cultivation.

Abstract

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