Enzymatic extraction of growth factor in Chlorella and possible protective effects of Chlorella extracts on yeast growth

Microalgae have been known as potential sources of proteins and bioactive compounds, these microscopic algae have fueled interest in different research fields. While different extraction techniques have been applied for the recovery of bioactive compounds from these sources, high extractability remains a major concern. Chlorella, a prominent microalga, has been found to be an excellent source of carotenes, protein, fiber, vitamins, minerals, nucleic acids, polysaccharides, and chlorophyll, and could serve as a food source for yeasts. This work was aimed to assess the protective effect of Chlorella in yeast cells cultured in the ethanolic environment. Additionally, the use of enzymatic treatment was employed for the extraction of Chlorella growth factor (CGF). Dry Chlorella powder and water at 95 °C (as a solvent) have been used to prepare extracts. From our pilot study carried out to check the protective effect of Chlorella extract on yeast, it was found that culturing yeast in a Saburo medium (FBUN “SSC PMB,” Russia) supplemented with 0.1% concentration of Chlorella extract was found to greatly increase its (yeast's) viability up to 17 days. 100% viability was recorded on the 13th day of inoculation on the medium. It was found that the treatment of Chlorella algae with enzymatic preparation Cellulox-A (Sibbiopharm Ltd., Russia) increased the growth factor index from 3.5 to 7.5 (approximately 3% increment). The extractability of growth factor was observed to depend on extraction time with the optimal extraction yield obtained at 120 min. The original version of this article supplied to AIP Publishing contained errors in the acknowledgement section. The revised article, with the acknowledgement section corrected, was published on 12 January 2021.