Hossein Sadeghi - Department of microbiology and microbial biotechnology, faculty of Biological Sciences and Technologies, shahid beheshti university
Gholamhossein Ebrahimipour - Department of microbiology and microbial biotechnology, faculty of Biological Sciences and Technologies, shahid beheshti university
Seyyed Omid Ranaee Siadat - Protein Research Center, shahid beheshti university
Jamshid Fooladi - department of biotechnology, Faculty of Biological Sciences, alzahra university

Background and Aim:Histamine poisoning, an allergy like food poisoning, caused by ingesting scombroid fishes such as mackerel and tuna which have high amount of histidine in their muscle. histamine is formed by decarboxylation from histidine through the activity of microorganisms. Though it is not present in fresh fish, Histamine in fish is a good indicator of hygienic food quality. Current methods used for histamine determination (HPLC) are complicated, time-consuming and expensive to use for many food plant. Therefore it is essential to implement rapid and portable procedures for field analysis of fishery products. The main purpose of this study was the isolation of bacteria producing histamine oxidizing enzyme for development an enzymatic methods for histamine determination.Methods:For isolation bacteria with potent histamine oxidase several soil samples collected at different places in Iran. we used histamine as main nitrogen and carbon source in culture media. Then we designed primer sets for histamine oxidase gene and amplified by PCR. The histamine oxidase-producing bacteria were chosen from histamine-utilizing strainsResults:From the samples of soil, about 100 histamine-utilizing bacteria were isolated that 4 strain had histamine oxidase gene revealed by PCR amplification and gene sequencing. One strain, N1L4 was selected and used for further experiments. HPLC analysis of histamine degradation activity showed that N1L4 strain degrading up to 90 % of the histamine with 12 h of incubation at 37 oCConclusion:by optimization of the cultivation condition and purification, the N1L4 enzyme can be used for development of a test kit for histamine determination in fishery products.

histamine degrading bacteria, soil, Histamine oxidase enzyme, enzymatic determination