Synopsis The anxiety of man to explore nature and discover new forms and aspects of life has led to a vast heritage of knowledge and ideas. The diversity of microbial flora and their role in molding the ecology has always raised a number of queries in the human mind. The microorganisms have posed influence in the social and economic structure of human civilization from time immortal. The influences have been beneficial as well as detrimental. These effects points out the importance of research work in the field of microbial diversity. The present Prof. R.C. Rajak festschrift volume is a compilation of reviews/research papers related to various aspects of biodiversity viz., plant growth promoting microbes, yeast, endophytes, dermatophytes, pathogenic microbes, cyanobacteria, aeromicroflora, VAM etc. Articles related to the apthogenic bacteria, biofuel product, protoplast fusion, glucan production etc. are also included in this book. Articles are contributed by eminent researchers and have the responsibility about scientific values, literature citation utilization etc.