Isolation and characterization of halophilic and halotolerant extracellular nuclease producing bacteria from the West of Mazandaran

Halophilic microorganisms are considered as an important source of extracellular hydrolytic enzymes with high potential for industrial, pharmaceutical and biotechnological purposes. A sampling of saline springs in the west of Mazandaran province. To isolate the microorganisms from the selected culture medium, relative halophilic bacteria were used. Several re-cultivations were carried out to purify the bacteria. After the morphological identification of isolates, several biochemical diagnostic tests, such as TSI, OF, SIM, Catalase activity, and bacterial Oxidation were evaluated. Then, concentrations of 2.5 and 5% of salt were determined as the optimum concentration of saline growth. Screening of halophilic bacteria producing DNase enzyme was carried out on a medium containing the enzyme substrate. In addition to the compounds used in the DNase medium, some Toluidine Blue was added as a reagent. According to the salt content of each isolate, a certain percentage of salt was added to each enzymatic culture medium to provide optimum conditions for the growth of the isolates. Samples were incubated for 3 to 7 days for production of extracellular enzyme deoxyribonuclease at 37°C. The results showed that 5 isolates were able to change the culture medium around the colony from green to yellow, and thus, the nuclease activity of these isolates was evaluated positively.

Keywords:

Nuclease , Deoxyribonuclease , Extracellular hydrolytic enzyme , Halophilic bacteria