Muhammad Zaffar HashmiDr. Hashmi is Assistant Professor at the Department of Meteorology, COMSATS Institute of Information Technology, Islamabad, Pakistan. He completed his PhD in Environmental Engineering at the Zhejiang University, China. Dr. Hashmi research focused on Bioremediation of contaminated soil and cell toxicology. His books: Xenobiotics in the Soil Environment and Antibiotics and Antibiotics Resistance Genes in soils published by Springer are used at icolleges, universities and research institutions all over the world.Ajit VarmaAjit Varma (M.Sc., Ph.D.) was professor of microbial technology at the School of Life Sciences, Jawaharlal Nehru University, New Delhi, before he became Director of the AMITY Institute of Herbal & Microbial Research in 2004. Professor Varma has won a large number of coveted national and international awards for his scientific contributions and was elected Fellow ofthe National Academy of Agricultural Sciences of India. He has lectured on various aspects of microbial sciences worldwide and has been honored for his excellence in teaching at esteemed universities. His first two books, dealing with mycorrhizal research, were published in 1991-1992 by Academic Press (UK) and have been used at innumerable colleges, universities and research institutions all over the world. Since then, he has compiled 18 books produced by leading and prestigious scientific publishing houses. Prof. Varma is Chief Editor of the series "Soil Biology".