Iqbal Ahmad is Reader / Associate Professor in Microbiology at Aligarh Muslim University, Aligarh, India. His research interest in this area includes microbial diversity, PGPR, and metal-microbe interactions. Iqbal Ahmad has published 50 research papers and edited two books.

John Pichtel is Professor of Natural Resource and Environmental Management at Ball State University, Indiana, USA. He has published more than 40 scientific articles, and is member of several professional bodies including Certified Professional Soil Specialist, American Society of Agronomy.

Shamsul Hayat holds a senior faculty position in the department of botany at the Aligarh Muslim University, Aligarh, India. His major areas of research are phytohormones and heavy metal stress in plants and biofertilizers. Shamsul Hayat has edited three books and published more than 50 research papers.