Investigation of Protein Extraction from Microalgae Using Different Pretreatment Methods

Microalgae are promising sources of protein due to their high nutritional value, rapid growth rate and ability to survive in harsh conditions. In this study, first, different and indeterminate species of microalgae were cultured in flat plate photobioreactors and for the first time, the process of protein extraction from mixed microalgae biomass using various pretreatment methods such as autolysis, hydrolysis with acidic and alkaline methods, ultrasound and their composition was investigated. In acidic and alkaline pretreatment using solutions with different concentrations and at different times, the highest percentage of protein extraction (at 121 temperature and duration of 30 minutes) was 83% and 93%, respectively, which showed that the use of alkali was more efficient in protein extraction. Also, using autolysis and ultrasound methods, the highest extraction efficiencies were 60% and 39% of total protein, respectively. In this study, an autolysis with freezing method was used for the first time and based on the results, the efficiency of the autolysis process increased by 3 to 10%.