CSIR-Institute of Microbial Technology (IMTECH), Sector 39-A, Chandigarh, India.|CSIR-Institute of Microbial Technology (IMTECH), Sector 39-A, Chandigarh, India.|CSIR-Institute of Microbial Technology (IMTECH), Sector 39-A, Chandigarh, India. krishna@imtech.res.in.