The book is a maiden endeavor in the field of microbiology, especially on the topic mangrove fungi. The authors have made an attempt to study the diversity of mangrove fungi of Godavari delta of Andhra Pradesh, India and to exploit their biotechnological potential. a special focus is given on pigmented fungi.A fungus Penicillium marneffei isolated with red pigment is characterised.The pigment is extracted using various organic solvents. This red pigment is characterised through preparatory thin layer chromatography followed by GC-MS and NMR studies and observed to be 2-4-acetylphenyl-acetic acid derived from the parent molecule Ganbajunin. Attempts were made to optimize the pigment production through regulation of different culture conditions.Further, the pigment fractions were screened for their antimicrobial activities against human,animal and fish pathogens and the findings were promising. This book will definitely cater the need of academicians and researchers in this field of microbiology. At last the author CCR thank all the well wishers for their cooperation to bring this work as a book volume.