Heterologous mannitol-1-phosphate dehydrogenase gene over-expression in Parachlorella kessleri for enhanced microalgal biomass productivity

• Published in: Journal of Genetic Engineering and Biotechnology Vol. 20; no. 1; pp. 38 - 8
• Main Authors: Rathod, Jayant Pralhad, Vira, Chaitali, Lali, Arvind M., Prakash, Gunjan
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 28.02.2022; Springer; Elsevier
• Subjects: Abiotic stress, High-light, ROS; Biomass energy; Biomedical Engineering and Bioengineering; Engineering; Ethylenediaminetetraacetic acid; Genes; Genetic engineering; Genetic research; Mannitol; Metabolites; Microalgae; Phosphates; Photosynthesis; Purification; Sewage; Stress management; Wastewater; India; Microalgae; Mannitol; Abiotic stress, High-light, ROS
• ISSN: 1687-157X; 2090-5920
• DOI: 10.1186/s43141-022-00322-7

Background Microalgae have tremendous potential in CO 2 sequestration, bioenergy, biofuels, wastewater treatment, and high-value metabolites production. However, large-scale production of microalgae is hampered due to photo-inhibition in outdoor cultivation. Mannitol, as an osmolyte, is known to relieve the stress produced under different abiotic stress conditions during the growth of a photosynthetic organism. Results In the present study, Mannitol-1-phosphate 5-dehydrogenase ( Mt1D ) was over-expressed to study the effect of mannitol over-production in Parachlorella kessleri under high-light induced stress. Over-expression of Mt1D led to 65% increased mannitol content in the transformed P. kessleri compared to that of wild type. Mannitol transformant demonstrated > 20-fold reduction in reactive oxygen species generation and 15% higher biomass productivity when grown in outdoor cultivation with high-light irradiance of 1200 μmol photons m −2 s −1 . Conclusions The current study establishes that a higher mannitol concentration provides stress shielding and leads to better acclimatization of transgenic microalgae against high-light generated stress. It also led to reduced ROS generation and improved growth of microalga under study. Thus, overexpression of the Mt1D gene in microalgae can be a suitable strategy to combat high-light stress.