Enhanced astaxanthin production by oxidative stress using methyl viologen as a reactive oxygen species (ROS) reagent in green microalgae Coelastrum sp.

Abstract

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.

Enhancement of astaxanthin accumulation using black light in Coelastrum and Monoraphidium isolated from Malaysia

“…3 , Fig. S2 ) with the absorbance maxima at 480 nm (personal communication from Dr. Tharek, A 18 , Fig. S3 ) and 474 nm 19 , respectively.…”

“…More recently, astaxanthin production by Coelastrum sp. was shown to be enhanced by methyl viologen as the reactive oxygen species enhancer 18 . In case of Monoraphidium strain, previous study improved the photoautotrophic culture condition and outdoor cultivation method for increasing the astaxanthin content in Monoraphidium GK12 23 , 24 .…”

Kinetic modeling, optimization of biomass and astaxanthin production in Spirogyra sp. under nitrogen and phosphorus deficiency

“…A previous study showed that astaxanthin production in Coleastrum sp. was enhanced through the introduction of ROS as a stress inductor into the cultivation medium, which increased production by 1.3-fold (Tharek et al 2020). Nitrogen (N) and phosphorous (P) are both essential for algal growth and therefore play an important role in astaxanthin productivity (Fan et al 2021; Li et al 2022.…”

Improvement and screening of astaxanthin producing mutants of newly isolated Coelastrum sp. using ethyl methane sulfonate induced mutagenesis technique

“…Therefore, several strategies have been employed for a more economical algae culture in increasing the levels of astaxanthin production in green microalgae. Significant efforts have been undertaken to improve astaxanthin production by selecting high yield strains, optimize cultivation and uses of chemicals as metabolic enhancers of astaxanthin [ 16 , [ 50 ] 17 ] . Nevertheless, the progress of this improvement method has yet to be fully satisfied.…”