بررسي توليد و فعاليت آنزيم پري پلاسميك آلكالين فسفاتاز در سويه‏هاي بومي E.coli جدا شده از آب‏هاي منطقه رودسر

Production and activity of periplasmic alkaline phosphatase in native E.coli strains isolated from waters of Rudsar area

The purpose of present survey was study the effective factors (determining induced and limiting factors) in biosynthesis and activity of alkaline phosphatase in the native E.coli strains. In this survey, 50 different wells from the city of Rudsar were sampled and inspected for existence of E.coli. Following screening test, one strain capable of enzyme production was selected as a suitable strain. The specific substrate (4-Nitrophenyl phosphate disodium salt hexahydrate) was used for measuring enzyme activity. In present study the highest enzyme production was observed in base medium after 64 hours of growth and in optimum medium after 40 hours of growth in the early stationary phase. The most effective factors were as follows : Glucose 0/5% of carbon sources ,Bactopeptone 0/5% of nitrogen sources , NaCl 0/6% of various concentrations of NaCl, Inoculation 6% of inoculation rate, 6% , pH 7.5 and 37 ° C temperature. The inorganic phosphate was appeared to be as limiting factors. The aerobic condition was best condition to production of enzyme and maximum activity of enzymen was at 37 ° C and pH 8.5. The thermal shock had best results for releasing the enzyme from periplasmic space. The endurable period of the enzyme obtained by thermal shock was 7 days in 2-8 ° C fridge temperature. The maximum enzyme production rate in optimum medium and base medium were 32/97 and 7/62 (U/ml/min) respectively.