Microalgae as cell factory for biofuel production

Large scale production of algal biomass for commercial application is recommended to be obtained mostly in open, "raceway" pond or closed photobioreactor via photoautotrophic cultivation. However, this commonly used way of algal cultivation suffers from various limitations. To address these existing bottlenecks we propose to use Photovoltaic Airlift Photobioreactor (PAPB) for high cell density cultivation of microalgae using natural light source (sunlight) in a closed environment. An Energy Efficient Electrochemical Harvesting (EEECH) technology is being developed to minimize the cost on downstream process. We are also interested to develop sustainable pilot scale production technology for hydrocarbon oil via hydrothermal liquefaction (HTL) of microalgae grown on flue gas and organic nutrients recycled from HTL unit which will be economically feasible and environmentally safe.

Further, we seek to achieve a deeper understanding of the interaction between growth and product formation, biochemical energy, carbon fixation and assimilation pathway. Our group is performing a combined task of biochemical characterization, comparative proteomic study and flux balance analysis of the model algal strain grown under various growth conditions in order to identify the key process parameters, regulatory proteins and dominant pathways which could be the possible targets for modifications. Based on the findings we will propose a strategy to improve overall performance of the technology via combined modifications at the process (Biochemical engineering approach) and strain level (genetic engineering approach). This work is in collaboration with Dr. Sanjeeva Srivastava, Department of Bioscience and Bioengineering, IIT Bombay. The lab is equipped with large scale production facilities e.g. open raceway pond of 500 L to 2000 L capacity, airlift photo bioreactor of 50 to 1000 L capacity, automated photobioreactor of 3-7 L capacity and all major analytical facilities. The projects are funded by SERB, ONGC, DBT-BCIL, DST, DBT etc.

Development of Clostridium sp. as a cell factory for butanol production

Commercial scale butanol production using Clostridium sp. suffers from key limitations: solvent toxicity and low butanol titer. To that end, present work aims to offset these limitations through combined metabolic engineering, system biology and process engineering approaches. As a result, a sustainable and scalable bioprocess with in situ solvent recovery will be developed using a butanol overproducing Clostridium strain with improved solvent tolerance.

Engineering simultaneous transport of hexose and pentose sugars in Zymomonas mobilis for biofuel production from lignocellulosic waste

Zymomonas mobilis is a promising organism for biofuel production as it can efficiently produce ethanol at rates greater than those reported for yeast. However, the organism suffers from a disadvantage - it does not possess the necessary genes for utilizing pentose sugars. When these genes are introduced from other organisms, it is able to ferment arabinose and xylose in a sequential manner, leading to long processing times. This sequential utilization is not due to regulation or an inherent hierarchy but due to inefficient transport of pentose sugars. This proposal aims to address issues related to effective, simultaneous transport of sugars. The project is implemented through DBT-Pan IIT center for Bioenergy and in collaboration with Dr. Supreet Saini of IIT Bombay.

Microalgae as biofactories for high value products and derived pharmaceutical

Production of high value products Eicosapentaenoic acid (20: 5) and Decosahexaenoic acid (22: 6) (Omega-3 [(n-3)] long-chain PUFA) from microalgae. Commercially produced as a nutritional supplement and applied in prevention of cardiovascular and neurodegenerative diseases. Microalgae as primary producer have potent ability to store EPA and DHA and reduce excess demand from fish stock. Research focus is on developing novel process strategies to maximize algal biomass, optimization of bioprocess parameters to enhance intracellular EPA and DHA content and to improve efficiency of extraction techniques

Phycoerythrin, Phycocyanin, Allophycocyanin are brilliantly coloured, highly fluorescent protein-pigment complexes known for antioxidant properties. These high-value natural products have potential applications in biomedical research (immunoassays, flow cytometry and fluorescent markers and dyes) nutraceuticals, food colorants , pharmaceuticals, cosmetic industries.Microalgae are capable of producing metabolites in large amounts over short periods of time under simple growing conditions. Red algae and cyanobacteria have natural innate ability to produce phycobilins and this can be exploited with a bioprocessing approach. The prime focus of research is on identification of potent strains, development of strategies to enhance biomass productivity, yield and improve protein extraction and purification efficiency.