Laboratory evolution of microalgae species, chlorella sorokiniana, for usage in sustainable food production

Abstract

Incorporating microalgae to meet the increasing demand for sustainable food production is hindered by wild type (WT) microalgal strains lacking desirable industrial traits such as increased tolerance to environmental stressors. Random mutagenesis is a useful method to genetically modify organisms to achieve various goals, such as inducing tolerances and increased biomass productivity. Although there is increased interest in improving microalgae strains for usage in food applications, there are a lack of current research available on the synergistic effects of random mutagenesis and adaptive laboratory evolution (ALE) on microalgae. In the present study, a hybrid approach of utilizing random mutagenesis and salinity stress was performed on Chlorella sorokiniana (C. sorokiniana) to potentially enhance its tolerance to high salinity levels as well as improvement to the growth rate and biomass productivity. The study was conducted in two different phases. Based on the results obtained, it was found that C. sorokiniana was able to adapt to 0.3M NaCl salinity, with the highest optical density of 6.99 found in the non-mutagenized condition. However, when subjected to 0.4M salinity, C. sorokiniana struggled to adapt even under mutagenized conditions, with highest optical density reached at a low value of 4.27 under non-mutagenized condition. Overall, the increased in salinity levels had negatively affected the growth of C. sorokiniana Alternative methods like genome shuffling can be used to try and improve the salinity stress tolerance of C. sorokiniana, Therefore, this study aims to develop robust C. sorokiniana strains capable of tolerating high salinity by using random mutagenesis and ALE, thereby allowing for further advancements in sustainable food production.