Isolation and molecular identification of bacteria producing alkaline phosphatase enzyme from environmental sources

Document Type : Research Article


1 Young Researchers and Elite Club, Gorgan Branch, Islamic Azad University, Gorgan, Iran

2 Department of Microbiology, Faculty of Basic Sciences, Islamic Azad University, Gorgan Branch


Alkaline phosphatase (ortho phosphate, monoester hydrolase phosphoinositide E. C. is a non-specific metalloproteinase enzyme that is located inside periplasmic space of bacteria. This enzyme is used to measure freshwater sediment in genetic engineering for cleaning water. Isolation and molecular identification of the bacteria producing alkaline phosphatase and comparison of its production rate in samples collected from different environmental sources including soil, wastewater and yogurt were the objectives of this study. Different environmental samples including soil, wastewater, stool and dairy products were cultured on the specific medium of phenolphthalein phosphate. Then, the bacteria producing the enzyme were isolated and identified based on the colony morphology, biochemical tests and finally PCT test and ribotyping. After the incubation, only the medium cultured with wastewater showed colonies that were discolored and pinkish. BLAST results of the samples confirmed the existence of Enterococcus durans, Shewanella putrefaciens and Shewanella xiamenensis; Shewanella putrefaciens with the highest concentration rate (87.48 u/l) was selected as the most superior strain. Investigating the enzyme concentration using a spectrophotometer at wavelength of 405 nm determined that the wastewater mediums were the only medium has potential to produce alkaline phosphatase enzyme among environmental sources of soil, wastewater, stool and yogurt. Other environmental samples did not show any potential for enzyme production.


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