Antioxidant Activity and total Phenolic Content of Defatted Scenedesmus quadricauda KDPSC2 Biomass Extract by Microbial Fermentation

Abstract

Microalgae biomass are considered as sustainable sources for various bioactive compounds. The objective of this study to evaluate the defatted biomass of green microalga Scenedesmus quadricauda KDPSC2 as a source for enhancement of total phenolic content (TPC) and antioxidant activity by microbial fermentation. Ultrasonic assisted hydrolysate was prepared from defatted biomass using ultrasound power density of 0.3 Wcm-2 at 10 min. Then the prepared defatted biomass hydrolysate (DBH) was used as soul medium for fermentation by five different microbial strains such as Bacillus amyloliquefaciens, B. stearothermophilus, B. subtilis, Saccharomyces cerevisiae NITTS1 and Cyberlindnera jadinii MMS7. Among these microbial strains, C. jadinii MMS7 was selected for further study because it was enhanced the TPC and antioxidant activity of DBH by fermentation. Besides, the fermentation conditions were optimized by classical method of optimization and found the pH 5.5, temperature 35 oC, agitation speed 150 rpm and 36 h as optimum physical parameters for enhancing the TPC and antioxidant activity of DBH by fermentation using C .jadinii MMS7. At these optimum conditions, 4.67 fold DPPH radical scavenging activity was obtained from DBH after fermentation. Therefore, this study demonstrates that the defatted biomass of S. quadricauda KDPSC2 could be a useful source for production of TPC by C. jadinii MMS7 fermentation.
 Keywords: Cyberlindnera jadinii, Defatted biomass, Fermentation, Hydrolysate, Scenedesmus quadricauda, Total phenolic content.