Phosphate obtained from microbial dissolution of phosphate ore consider one of the most vital recent methods, less
expensive , environmentally friendly and energy saving. This process of dissolution do not need concentrate phosphate crude
ore and not use specific strains of microorganism, where microorganisms were isolated from the phosphate ore as single
organisms that have the most efficacy in phosphate dissolution or use mixure of microbial community of phosphate ore in
dissolution to micic natural condition . The effect of different energy carbon and nitrogen sources on bacterial growth was
evaluated during this work. Also the effect of Azotobacter vinelandii bacterial strain ,inoculum size was evaluated through
this work for phosphate dissolution. production of (phosphate nitrogen) PN is cheap from local ores by harness the power
of microorganisms as ore dissolution.
The optimum conditions of Abu Tartur phosphate ore dissolution were 28 hour incubation period, with growth on
modified PVK medium as the best medium for dissolution of Abu Tartur phosphate ore, 2.9 log colony forming unit of
Azotobacter vinelandii per 50 ml medium as inoculm size, 0.5% Abu Tartur phosphate ore concentration , incubation
temperature at 30°C, ammonium oxalate as potential nitrogen source, glucose as potential carbon source. The leaching
efficiency of phosphate content in Abu Tartur phosphate ore reaches to 52.6%.