Research Groups

Metabolic Engineering

Research Interests and Description

Group Leader: Shashi Kumar Rhode, PhD

Group Members

Link to DBT-ICGEB Bioenergy Centre

Research Interests

Super algal strains for sustainable biofuel; Terpenoid drugs biosynthesis in plants using Synthetic Biology and Metabolic Engineering tools; Engineering of Carbon Concentration Mechanism (CCM) in algae for sequestrating higher CO2; Remediation of wastewater by algae and biomass generation for bioenergy; Syntrophy between algae and endophytic fungus; Chloroplast and nuclear genome editing of photosynthetic organisms for value added products; DNA Barcoding; Insect-pests gene silencing via chloroplast mediated RNA interference.

Description of Research

Super Algal strains for biofuel
With the application of genome editing tools, we are developing algae that grow fast, sequester higher CO2 and produce more oil, which is required for sustainability of renewable algal biofuel. The ribulose bisphosphate carboxylase-oxygenase (Rubisco) of aquatic photosynthetic microalgae faces several challenges in acquiring CO2 from the surrounding environment. To enhance the supply of CO2 to Rubisco, we have genetically engineered an oleaginous marine Chlorophyta Parachlorella kessleri-I (I for ICGEB) with the heterogeneous inorganic carbon transporters LCIA and LCIB. This rewiring approach of carbon concentrating mechanism (CCM) has considerably enhanced the photosynthetic activity of Rubisco in transgenic and resulted in four fold higher biomass productivity and higher lipid content in compare to wildtype. The upscale study of this super algal is under progress for producing the biofuel at commercially viable scale. This work is supported by the Department of Biotechnology, Government of India as well as supported by innovative companies, Aban Inc., Chennai Petroleum Chemical Limited (CPCL), and Reliance Industries Limited (RIL).

Cleaning wastewater by algae and bioenergy
It is estimated that human societies produce about 3 billion tons of domestic wastewater every year and ~4400 million cubic meters of it only in Delhi. Therefore, our research focus is the robust microalgal strains that can play a crucial role remediating the wastewater and producing the biomass for bioenergy. Municipal wastewater, if not properly remediated, poses a threat to the environment and human health by carrying significant loads of nutrients and pathogens. These contaminants pollute rivers, lakes and natural reservoirs where they cause eutrophication and pathogen-mediated diseases. On the contrary, the high nutrient content of wastewater makes it ideal for the growth of algae. Thus, an appropriate algal strain can be used for the remediation of wastewater and the incurred biomass can be refined for the production of biofuel. Among the different strains tested using 100% wastewater, robust Parachlorella kessleri-I showed the highest growth rate and productivity. It efficiently removed all the major nutrients from 100% municipal wastewater of Delhi. The growth of P. kessleri-I in wastewater resulted in a 50% higher productivity and an 115% increase in lipid content when compared to control media. The present study provides evidence that the robust marine alga P. kessleri-I can effectively remediate the municipal wastewater while producing the biomass for biofuels. 

Terpenoid Drugs Biosynthesis in plants
The anticancer drug taxol and antimalarial drug artemisinin, cannabinoids, curcuminoids, ginkgolides, salvinorin-A, and menthol are some of the popular terpenoid-based drugs. Artemisinin, a plant derived medicine has proven to be one of the most effective drugs against malaria. It treats malaria faster than any other drug available in the market. Low yield of artemisinin from the native plant (Artemisia annua) combined with high cost of extraction and purification make it unaffordable for the poor - people who need it most are not able to afford it even after a subsidy provided by the Government of India. With synthetic biology approaches, we have produced this drug at clinically meaningful levels. The rationalised expression of biosynthetic pathway’s genes in three different organelles of the plant has enabled us to attain the maximum yield using the double transformation approach. Extract from the double transgenic plants inhibited in vitro growth progression of Plasmodium falciparum in human red blood cells. Oral feeding of whole intact plant cells bioencapsulating the artemisinin reduced the parasitemia levels more effectively in challenged mice in comparison with commercial artemisinin. Our focus is to find a new way to make this drug affordable and available to more people using edible plants.

Metabolic engineering for hypoallergenic latex
We are interested in genetic engineering of guayule to enhance the yield of natural rubber by removing the monomer substrate limitation. Guayule (Parthenium argentatum) is an important commercial crop of the rubber industry. Its rubber is distinct from Hevea brasiliensis rubber due to its hypoallergenic properties (allergy causing proteins are absent). Patented US 20140325699 (granted in 2016). WO/2014/152747.

Recent Publications

Kunrunmi, O., Adesalu, T., Kumar, S. 2017. Genetic identification of new microalgal species from Epe Lagoon of West Africa accumulating high lipids. Algal Research 22, 68-78. https://doi.org/10.1016/j.algal.2016.12.009 

Singh, A.K., Sharma, N., Farooqi, H., Abdin, M.Z., Mock, T., Kumar, S. 2017. Phycoremediation of municipal wastewater by microalgae to produce biofuel. Int J Phytoremediation 19, 1-8 PubMed link

Malhotra, K., Subramaniyan, M., Rawat, K., Kalamuddin, M., Qureshi, M.F., Malhotra, P., Mohmmed, A., Cornish, K., Daniell, H., Kumar, S. 2016. Compartmentalized metabolic engineering for artemisinin biosynthesis and effective malaria treatment by oral delivery of plant cells. Mol Plant, 9, 1464-1477 PubMed link

Singh, D., Kumar, S., Daniell, H. 2016. Expression of Beta-glucosidase increases trichome density and artemisinin content in transgenic Artemisia annua plants. Plant Biotechnol J 16, 1034-1045 PubMed link

Ahmad, I., Sharma, A., Daniell, H., Kumar, S.2015. Altered Lipid Composition and Enhanced Lipid Production in Microalga by Introduction of Brassica Diacylglycerol Acyltransferase 2. Plant Biotechnol J, 13, 540-550 PubMed link

Shao, M., Kumar, S., Thomson, J.G. 2014. Precise excision of plastid DNA by the large serine recombinase Bxb1. Plant Biotech J 12, 322-329 PubMed link

ICGEB New Delhi

ICGEB Campus
Aruna Asaf Ali Marg
110 067 New Delhi
INDIA
Tel: +91-11-26741358/1007
Fax: +91-11-26742316
icgebicgeb.res.in

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