Sr. Prof. Rani Gupta
Area of research: Applied and Industrial Microbiology
Our group has been working on industrial enzymes like protease, lipase, amylase and chitinase since past thirty years. Current research is focused on keratinase, lipase and gamma-glutamyl transpeptidase. Our laboratory is continuously engaged in isolation and identification of bacterial and yeast isolates from selective habitats through enrichment methods to select potential enzyme producers. We work towards strain improvement by taking a protein to gene approach involving the methods of cloning, heterologous expression and developing a variety of vector-host combinations. This is followed by biochemical and biophysical studies of the proteins. In-silico structural and functional analysis including homology modeling, docking, etc. is conducted to solve the protein structure. Site directed mutagenesis is often employed to validate the in-silico analysis. Another key area is protein engineering to obtain catalytically efficient enzymes. We also work on scale-up of the proteins and their industrial applications.
Our lab has identified a novel bifunctional keratinase enzyme from Bacillus licheniformis and characterized it in detail. It has been used as an ungual enhancer to prepare an enzyme-based formulation for increased drug permeation to nail plate. In addition, biochemical and molecular characterization of keratinases from Bacillus pumilus have also been documented. Chitin conjugates of the same have been demonstrated to degrade prion like protein, Sup 35NM under ambient conditions. Molecular characterization of keratinases from Bacillus sp. have also been done to establish the effect of pro-sequence on thermostability and substrate specificity of enzyme. Further, a novel keratinase from Pseudomonas aeruginosa has also been documented for the first time. Redox mechanism underlying the degradation of recalcitrant proteins has been deciphered. Coupled action of γ-glutamyl transpeptidase-glutathione and keratinase has been shown to effectively degrade feather and Sup 35NM. In addition to the above, novel yeast lipases have been described. Six lipases from Yarrowia lipolytica have been characterized in detail. Lipase genes from Trichosporon sp. have also been isolated, sequenced and characterized for the first time. Gamma-glutamyl transpeptidase enzyme from Bacillus licheniformis and Bacillus atrophaeus have also been expression heterologously and characterized by biochemical and biophysical methods.
Apart from biochemical and molecular characterization of microbial enzymes, our lab also focuses on development of bench-scale bioprocesses for various industrial applications of microbial enzymes. We have developed a complete process for the conversion of chicken feather, regarded as recalcitrant waste, to feather meal by using microbial keratinase which can be used us poultry feed. Bioprocess for enzymatic synthesis of L-theanine using gamma-glutamyl transpeptidase enzyme from Bacillus licheniformis ER15 has been developed along with downstream processing of the product.
Bindal, S., & Gupta, R. (2017). Hyperproduction of gamma-glutamyl transpeptidase from Bacillus licheniformis ER15 in the presence of high salt concentration. Preparative Biochemistry and Biotechnology, 47, 163-172.
Bindal, S., Sharma, S., Singh, T. P., & Gupta, R. (2017). Evolving transpeptidase and hydrolytic variants of gamma-glutamyl transpeptidase from Bacillus licheniformis by targeted mutations of conserved residue Arg109 and their biotechnological relevance. J of Biotechnology, 249, 82-90.
Dua, A., & Gupta, R. (2017). Functional characterization of hormone sensitive-like lipase from Bacillus halodurans: synthesis and recovery of pNP-laurate with high yields. Extremophiles, 21, 871-889.
Syal P., Verma V V., & Gupta, R. (2017). Targeted mutations and MD simulations of a methanol-stable lipase YLIP9 from Yarrowia lipolytica MSR80 to develop a biodiesel enzyme. IntJ Biol Macromo, 104, 78-88.
Bindal S and Gupta, R. (2016). Thermo- and salt-tolerant chitosan cross-linked γ-glutamyl transpeptidase from Bacillus licheniformis ER15. IntJ Biol Macromol. 91, 544-553.