This edited book covers the major aspects of plant growth promoting bacteria and mechanisms underlining the phenotype in rhizobacteria. This book guides the researchers about the potential of plant growth promoting bacteria to be used as biofertilizers. The process of biofertilizer development and the process of testing its efficacy for commercial use and the potency is elaborated in this volume using suitable figures. The information in this book regarding the secretion of various secondary metabolites responsible for nutrient management is helpful for designing bioformulations that assist plant growth. This book provides substantial number of evidences that underlines the genomic basis of nutrient management by microbes. Essential information is provided regarding the genomic and proteomic background of the biofertilizers. The chapters in the book are divided into three sections. The first section of the book includes chapter 1-5 outlining the importance of rhizobacteria in elevating the nutrient levels in soil and augmenting the biotic and abiotic stress. Second section of the book includes chapter 6-11 elaborating the details about the biofertilizer, types of biofertilizer available and techniques involved in mass production of biofertilizers. Section third covers chapters from 12-15 providing the explicit information about metabolomics and proteomics basis of plant growth development. This collective work is distinct as it has focus on diverse emerging technologies which are high-throughput, scalable and applicable to different countries regardless of their socio-economic conditions. This book can improve the current state of knowledge and invoke researchers and innovators to take ahead the current inter-disciplinary knowledge into technologies that are readily available and effectively minimize hazards associated with chemical fertilizer.