1 School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, India. Electronic address: isthakur@mail.jnu.ac.in.
2 School of Chemical Engineering, Universiti Sains Malaysia, Penang, Malaysia. Electronic address: leekeatteong@gmail.com.
3 School of Biomedical Sciences, University of Ulster, Coleraine, Northern Ireland, UK. Electronic address: p.singh@ulster.ac.uk.
4 Centre for Biofuels & Biotechnology Division, CSIR-National Institute of Science and Technology, Trivandrum, India. Electronic address: rajeevs@niist.res.in.