Search

Microalgae are known to be a potential resource of high-value metabolites that can be used in the growing field of biotechnology. These metabolites constitute valuable compounds with a wide range of applications that strongly enhance a bio-based economy. Among these metabolites, astaxanthin is considered the most important secondary metabolite, having superior antioxidant properties. For commercial feasibility, microalgae with enhanced astaxanthin production need to be developed. In this study, the tropical green microalgae strain, Coelastrum sp., isolated from the environment in Malaysia, was incubated with methyl viologen, a reactive oxygen species (ROS) reagent that generates superoxide anion radicals (O2-) as an enhancer to improve the accumulation of astaxanthin. The effect of different concentrations of methyl viologen on astaxanthin accumulation was investigated. The results suggested that the supplementation of methyl viologen at low concentration (0.001 mM) was successfully used as a ROS reagent in facilitating and thereby increasing the production of astaxanthin in Coelastrum sp. at a rate 1.3 times higher than in the control.

Natural astaxanthin is known to be produced by green microalgae, a potent producer of the most powerful antioxidant. To increase the productivity of astaxanthin in microalgae, random mutagenesis has been extensively used to improve the yield of valuable substances. In the presented work, a newly isolated Coelastrum sp. was randomly mutagenized by exposure to ethyl methane sulfonate and further screened using two approaches; an approach for high growth mutant and an approach for high astaxanthin producing mutant with a high-throughput screening method using glufosinate. Among these, mutant G1-C1 that was selected using glufosinate showed the highest of total carotenoids (45.48±1.5 mg/L) and astaxanthin (28.32±2.5 mg/L) production, which was almost 2-fold higher than that of wild type. This study indicates that random mutagenesis via chemical mutation strategy and screening using glufosinate successfully expedited astaxanthin production in a mutated strain of a Coelastrum sp.

Coelastrum is a genus of green algae that belongs to the Scenedesmaceae family. There is little information available about this genus. A phylogenetic analysis of the ITS2 sequences showed that Coelastrum is a paraphyletic group. To better explore the phylogenetic status of this genus, we report the mitochondrial genome sequence of Coelastrum sp. F187 using next-generation sequencing technology. The complete mitochondrial genome is 52,888 bp in size and encodes 43 conventional mitochondrial genes, including 14 protein-coding genes (PCGs), 24 transfer RNA (tRNA) genes, and four ribosomal RNA (rRNA) genes. Most of the PCGs (12/14) and all tRNAs were located in the heavy chain and the light chain, respectively. The phylogenetic analysis based on the complete mitochondrial genome sequences indicated that Coelastrum is closely related to Pectinodesmus pectinatus. The sequenced complete mitochondrial genome of Coelastrum sp. F187 provides fundamental molecular data that will be useful for species identification, population genetics, and evolutionary relationships.

Coelastrum is a genus of green algae that belongs to the Scenedesmaceae family. There is little information available about this genus. A phylogenetic analysis of the ITS2 sequences showed that Coelastrum is a paraphyletic group. To better explore the phylogenetic status of this genus, we report the mitochondrial genome sequence of Coelastrum sp. F187 using next-generation sequencing technology. The complete mitochondrial genome is 52,888 bp in size and encodes 43 conventional mitochondrial genes, including 14 protein-coding genes (PCGs), 24 transfer RNA (tRNA) genes, and four ribosomal RNA (rRNA) genes. Most of the PCGs (12/14) and all tRNAs were located in the heavy chain and the light chain, respectively. The phylogenetic analysis based on the complete mitochondrial genome sequences indicated that Coelastrum is closely related to Pectinodesmus pectinatus. The sequenced complete mitochondrial genome of Coelastrum sp. F187 provides fundamental molecular data that will be useful for species identification, population genetics, and evolutionary relationships. [ABSTRACT FROM AUTHOR]