Zinc Solubilizing Bacteria is a major nutrient &
effective solution to zinc deficiency problems. Zinc deficiency is related to
reduced root growth and activity. Lower microbial activity in the soil decreases
zinc release from soil organic matter, like other micro-nutrient. Zinc is not
mobile in plant, due to this it is necessary to supply Zinc to the plant for
Zinc is one of the imperative micronutrients required
relatively in small concentrations (5 –100 mg kg−1) in tissues for healthy
growth and reproduction of plants. Zinc deficiency in plants leads to reduced
membrane integrity and synthesis of carbohydrates, auxins, nucleotides,
cytochromes, and chlorophyll and develops susceptibility to heat stress.
Excessive use of zinc fertilizers also poses problems to humans causing the
impaired absorption of iron and copper.
Microbes are potential alternate that could cater plant
zinc requirement by solubilizing the complex zinc in soil. Several genera of
rhizo bacteria belonging to Pseudomonas spp. and Bacillus spp. are reported to
solubilize zinc. Microbes solubilize the metal forms by protons, chelated
ligands, and oxidoreductive systems present on the cell surface and membranes.
These bacteria also exhibit other traits beneficial to plants, such as
production of phytohormones, antibiotics, siderophores, vitamins, antifungal
substances, and hydrogen cyanide.