RESUMEN
The inorganic phosphorus content, and distribution, structure and localization of polyphosphate in mycelia of zygomycetous fungi was evaluated. Ultrastructural cytochemistry was successfully used to identifying the localization and distribution of polyphosphate in Absidia cylindrospora, Gongronella butleri and Mucor javanicus. The results revealed differences in the cytochemical staining pattern in all species studied and a uniform labeling on the cellular surface (cell wall and citoplasmic membrane). Reaction products were observed in intracellular structures and cellular membrane. Intracellular staining was observed in trabecullar, vacuolar and vesicular structures, in dense bodies and in the cytoplasm. However, the cytochemical staining intensity varied during the cellular growth. Analytical procedure revealed the phosphorus content during cell growth. The results demonstrated that phosphorus content varied during cultivation time and could be related to the polyphosphate cytochemical staining. Polyhosphate functions such as storage and utilization are discussed.