Isfahan University of Technology Dryland Soil Research (DLSR) 3115-9486 2 1 2025 03 01 Understanding sulfur dynamics in soil ecosystems: applications of sulfur-oxidizing bacteria– a review 1 15 3730 10.47176/dlsr.02.01.1034 EN Hossein Besharati Agricultural Research, Education and Extension Organization, (AREEO), Soil and Water Research Institute, Karaj, Iran Maryam Samani Department of Soil Science, University of Zanjan, Zanjan, Iran Ahmad Asgharzadeh Agricultural Research, Education and Extension Organization, (AREEO), Soil and Water Research Institute, Karaj, Iran Journal Article 2025 04 06 Sulfur (S) is an essential element for plants, playing a crucial role in various biochemical processes that are vital for their health.. Insufficient sulfur in the soil can profoundly affect plant health and crop yield. Agriculture commonly relies on sulfur fertilizers containing either sulfate or elemental sulfur (S^o) as a sulfur source. However, S^o, being more cost-effective and less prone to leaching than sulfate<span style="text-decoration: line-through;"> </span>(SO₄^-2) is favored, but, S^o must undergo oxidation to sulfate before plants can readily utilize it, a process largely facilitated by soil microorganisms. The environmental conditions affecting microorganism populations and activities significantly influence S^o oxidation. Sulfur-oxidizing bacteria (SOB) are instrumental in sulfur cycling within soil ecosystems, impacting their availability and transformation. This review delves into the intricate connections among S dynamics, SOB, soil improvement, and plant nutrition. It explores how plants obtain and employ S, stressing its significance in protein synthesis, enzyme activation, and secondary metabolites production. Additionally, the review scrutinizes SOB's role in mediating S oxidation, which influences soil pH, nutrient availability, and plant-microorganism interactions. Moreover, it discusses the potential of SOB as biofertilizers to enhance sulfur availability and bolster plant growth. Various strategies for leveraging the beneficial effects of SOB in sustainable agriculture are examined, such as microbial inoculation. The review also addresses the environmental implications of sulfur cycling, emphasizing the importance of maintaining balanced sulfur levels in soil ecosystems to mitigate environmental pollution and optimize agricultural productivity. In conclusion, this review offers valuable insights into the dynamic relationship between sulfur, SOB, soil fertility, and plant nutrition. It underscores the potential applications of this understanding in sustainable agriculture and ecosystem management, emphasizing the necessity of sulfur management for fostering agricultural productivity and environmental sustainability. https://dlsr.iut.ac.ir/article_3730_d8c24ca8f23c562a5600876ca2a550ce.pdf