Cyanobacterial biorefinery: Towards economic feasibility through the maximum valorization of biomass Syama Prabha, Aravind K. Vijay, Rony Rajan Paul, Basil George Science of the Total Environment, 2022 Cyanobacteria are well known for their plethora of applications in the fields of food industry, pHarmaceuticals and bioenergy. Their simple growth requirements, remarkable growth rate and the ability to produce a wide range of bio-active compounds enable them to act as an efficient biorefinery for the production of valuable metabolites. Most of the cyanobacteria based biorefineries are targeting single products and thus fails to meet the efficient valorization of biomass. On the other hand, multiple products recovering cyanobacterial biorefineries can efficiently valorize the biomass with minimum to zero waste generation. But there are plenty of bottlenecks and challenges allied with cyanobacterial biorefineries. Most of them are being associated with the production processes and downstream strategies, which are difficult to manage economically. There is a need to propose new solutions to eliminate these tailbacks so on to elevate the cyanobacterial biorefinery to be an economically feasible, minimum waste generating multiproduct biorefinery. Cost-effective approaches implemented from production to downstream processing without affecting the quality of products will be beneficial for attaining economic viability. The integrated approaches in cultivation systems as well as downstream processing, by simplifying individual processes to unit operation systems can obviously increase the economic feasibility to a certain extent. Low cost approaches for biomass production, multiparameter optimization and successive sequential retrieval of multiple value-added products according to their high to low market value from a biorefinery is possible. The nanotechnological approaches in cyanobacterial biorefineries make it one step closer to the goal. The current review gives an overview of strategies used for constructing self-sustainable- economically feasible- minimum waste generating; multiple products based cyanobacterial biorefineries by the efficient valorization of biomass. Also the possibility of uplifting new cyanobacterial strains for biorefineries is discussed.
Effect of auxin and its synthetic analogues on the biomass production and biochemical composition of freshwater microalga Ankistrodesmus falcatus CMSACR1001 Aravind K Vijay, Syama Prabha, Jubin Thomas, Jeeva Susan Kurian, Basil George Journal of Applied Phycology, 2020 Exogenous supplementation of phytohormones to promote the selective enrichment of biomolecules without hampering biomass production is regarded as a promising approach to improve the techno-economic feasibility of biofuels and other value-added products derived from microalgae. The present work outlines the influence of natural auxin, indole-3-acetic acid (IAA) and two synthetic analogues, 1-naphthalene acetic acid (NAA), and 2,4-dichlorophenoxyacetic acetic acid (2,4-D) on the growth pattern and biochemical productivity of the green alga Ankistrodesmus falcatus CMSACR1001. A maximum biomass production of 431 mg L−1 with a concomitant increase in the protein and carbohydrate content (20.2% and 49.6% DCW respectively) was achieved under supplementation of 10 μM IAA. Biomass productivity at 1 μM concentration was found to be comparable for both IAA and NAA (32.8 mg L−1 day−1 and 32.4 mg L−1 day−1). At higher supplemented concentrations 2,4-D induced a 30–40% increase in carotenoid production and exhibited an increased lipid content of 41–47% DCW as compared with control (34.2% DCW). The current study also reports a substantial increase in the neutral lipid proportion as much as 73.9% and 79% under supplementation of NAA and 2,4-D respectively at 100 μM. The results indicate that the auxin and its analogues under the study could increase the biomass production and favourably modulate the biochemical composition of A. falcatus.
Microalgal carotenoids: Potential nutraceutical compounds with chemotaxonomic importance Chetan Paliwal, Tonmoy Ghosh, Basil George, Imran Pancha, Rahulkumar Maurya, Kaumeel Chokshi, Arup Ghosh, Sandhya Mishra Algal Research, 2016 There are more than 600 different carotenoids which perform a range of functions in various organisms including microalgae. In the present study, chemosystematics approach was followed to segregate 57 microalgal strains based on their carotenoid composition using principal component analysis (PCA) and hierarchical clustering. The present findings suggest that lutein and violaxanthin can be effective chemotaxonomic markers for Chlorophyta members with an average content of 1.26 mg g − 1 and 0.14 mg g − 1 dry cell weight (DCW), respectively. Similarly, myxoxanthophyll and echinenone can be used as markers for Cyanophyta members with average contents of 0.23 mg g − 1 and 0.32 mg g − 1 DCW, respectively. The total carotenoid content ranged from 0.23 to 7.2 mg g − 1 DCW. Our method combining PCA and artificial hierarchical clustering has been proposed as an alternative method for identification of carotenoids as biomarkers for classifying unknown microalgal strains based on their pigment profiles.
