A comparison of the morphological and biochemical characteristics of Chlorella sorokiniana and Chlorella zofingiensis cultured under photoautotrophic and mixotrophic conditions

Abstract

The responses of two species of microalgae, Chlorella sorokiniana and Chlorella zofingiensis, were compared regarding their morphological and biochemical properties under photoautotrophic and mixotrophic conditions. These microalgae were cultured under both conditions, and their crude ethanolic extracts were examined for their pigment and total phenolic contents. In addition, the microalgae’s antioxidant activities were determined using a DPPH radical scavenging assay and a ferric reducing antioxidant power (FRAP) assay. Both strains showed increases in cell size due to the accumulation of lipid bodies and other cell contents, especially carotenoids, under the mixotrophic condition. Notably, reductions in phenolic and chlorophyll contents were observed to be associated with lower antioxidant activity. C. zofingiensis compared with C. sorokiniana, demonstrated higher antioxidant activity and carotenoid content. This study showed that different species of microalgae responded differently to varying conditions by producing different types of metabolites, as evidenced by the production of higher levels of phenolic compounds under the photoautotrophic condition and the production of the same levels of carotenoids under both photoautotrophic and mixotrophic conditions.

Identification and Analysis of microRNAs in Chlorella sorokiniana Using High-Throughput Sequencing

“…In a previous report, miR164 was found to regulate chlorophyll breakdown during leaf senescence in Arabidopsis thaliana [ 34 , 35 ] by targeting the no apical meristem, ATAF ½ and cup-shaped cotyledon (NAC) transcription factor involved in chlorophyll catabolism. Similarly, in this study, the chlorophyll content of C. sorokiniana grown under stress-induced conditions was reduced by 80% compared to cultures grown under normal conditions [ 3 ]. These findings demonstrate a possible correlation between the predicted function of the identified miRNA and the morphological study.…”

“…Chlorella is known as one of the best microalgae for the production of high-value metabolites such as carotenoids and lipids [ 1 , 2 ]. Microscopic observation of lipid-droplet and starch-granule accumulation in algal cells proved the potential of Chlorella as an alternative source for biofuel production [ 3 ]. Several researchers reported that the manipulation of different environmental factors could affect biochemical production from microalgae [ 4 , 5 ].…”

Genotype Versus Phenotype to Determine the Definitive Identification of the Genera Chlorella Beijerinck, 1890 (Chlorellaceae) and Coelastrella Chodat, 1922 (Scendesmaceae)

“…Morphological characteristics varied noticeably depending on many parameters such as environmental and nutritional represent by cultured media; Azaman et al (2017) proved that mixotrophic cultured medium and light intensity trigger morphological variations among both C.sorokiniana and C. zofingiensis; normal size of C. sorokiniana under standard growth conditions was 2 to 4 mm, and this size doubled when this alga grew under mixotrophic medium and under the higher light intensity with a result of increasing the size to approach even 9 mm due to an increase of cell contents. In another study, George et al (2014) demonstrated several changes in shape and size of cells growing in culture medium under 150 mmol photons; Chokshi et al(2015) have recorded that cells morphology varied due to the introduction of glucose to algae culture medium and the size of these cells increased 1-2 folds regardless of microalgae species.…”

Growth and secondary metabolites content of chloroform extract of Chlorella sp. and Chlorella sorokiniana cultured on chicken broiler waste media

“…Saponins generally possess antifungal and antibacterial activities (Feroz 2018). Chlorella sorokiniana contains phenolic compounds that have antioxidant activity (Azaman et al 2017). Chloroform extract of C. vulgaris contains saponins (Adhoni et al 2016;Syed et al 2015), and have antibacterial activity against Staphylococcus aureus, Corynebacterium, Bacillus subtilis, Streptococcus, Salmonella paratyphi B, Klebsiella pneumoniae, Aerobacter aerogenes, Candida albicans, and Aspergillus niger but it showed no growth inhibition against Escherichia coli (Adhoni et al 2016).…”