Pink Pigmented Facultative Methylotrophs (PPFMs): Bioinoculants for Sustainable Green Agriculture

Abstract

Bacteria belonging to the genus Methylobacterium, known as pink pigmented facultative methylotrophs (PPFMs), are gaining remarkable attention as potential bio-inoculants in agriculture. They are aerobic, Gram-negative bacteria, characterized by the capability to grow on single carbon compounds such as formate, formaldehyde or methanol as the sole source of carbon and energy. PPFMs are found in a wide variety of habitats such as soil, dust, freshwater lake sediments, leaf surface and nodules with reported symbiotic association with more than a hundred plant species. These beneficial groups of bacteria enhance the growth and yield of host plants through multifaceted modes of action such as production of phytohormones, vitamin B_12, siderophore, ACC deaminase, and nutrient acquisition. Moreover, they protect the plants by hindering infestation by various phytopathogens. Therefore, development of promising formulations of PPFMs with multiple beneficial traits could be an excellent alternative to agrochemicals in sustainable agriculture.