The article discusses the role of oxalic acid and oxalates in fungal and bacterial metabolism, highlighting their biotechnological potential. Oxalic acid, a widespread organic acid, is secreted by fungi, bacteria, and plants and plays a crucial role in various ecological processes. It is involved in nutrient availability, biomineralization, mineral weathering, and metal precipitation. Fungi, particularly those causing white rot of wood, are efficient in breaking down lignocellulose complexes, with oxalic acid acting as a key component in this process. The article also explores the biochemical pathways of oxalic acid biosynthesis and degradation in fungi, including the involvement of enzymes such as oxaloacetase and glyoxylate dehydrogenase. Additionally, it discusses the potential applications of oxalate-degrading and oxalotrophic bacteria in preventing kidney stone formation and their role in plant disease management. The oxalate-carbonate pathway, which links calcium oxalate oxidation and carbonate precipitation, is highlighted as an effective long-term sink for atmospheric carbon dioxide. The article concludes by emphasizing the importance of understanding the interactions between fungi and bacteria in the soil to fully grasp the environmental processes they facilitate.The article discusses the role of oxalic acid and oxalates in fungal and bacterial metabolism, highlighting their biotechnological potential. Oxalic acid, a widespread organic acid, is secreted by fungi, bacteria, and plants and plays a crucial role in various ecological processes. It is involved in nutrient availability, biomineralization, mineral weathering, and metal precipitation. Fungi, particularly those causing white rot of wood, are efficient in breaking down lignocellulose complexes, with oxalic acid acting as a key component in this process. The article also explores the biochemical pathways of oxalic acid biosynthesis and degradation in fungi, including the involvement of enzymes such as oxaloacetase and glyoxylate dehydrogenase. Additionally, it discusses the potential applications of oxalate-degrading and oxalotrophic bacteria in preventing kidney stone formation and their role in plant disease management. The oxalate-carbonate pathway, which links calcium oxalate oxidation and carbonate precipitation, is highlighted as an effective long-term sink for atmospheric carbon dioxide. The article concludes by emphasizing the importance of understanding the interactions between fungi and bacteria in the soil to fully grasp the environmental processes they facilitate.