Sulfur oxidizing bacteria in agro ecosystem and its role in plant productivity-a review

Sulfur (S) deficiency is becoming more common in agro-ecosystems worldwide due to factors such as agronomic practices, high biomass production, reduced sulfur emissions, and the use of non-sulfur fertilizers. This review explores the natural occurrence and commercial exploitation of sulfur pools in nature, the mineralization and immobilization of sulfur, the physiological role of sulfur in plants, and its deficiency symptoms. Additionally, the organic and inorganic forms of sulfur in soil, their transformations, and the process of microbiological oxidation of sulfur are discussed. The review also addresses the diversity of sulfur-oxidizing bacteria (SOB) and the various biochemical mechanisms involved in their role in plant productivity and soil reclamation. The measurement of S oxidation rate in soil and the variables that influence the process are also examined. Typically, the rate of oxidation of added elemental S is around 40%-51%, which is available for plant uptake. These characteristics of SOB demonstrate their potential as bioinoculants for increasing plant growth, indicating their use as biofertilizers for sustainable crop production in agro-ecosystems.