Preeyanuch Bovornreungroj. Isolation and Characterization of Salt-Loving Protease Producing Bacteria form Fish Sauce Samples. (). Kasetsart University. Office of the University Library. : , ม.ค.-มี.ค. 2548.
Isolation and Characterization of Salt-Loving Protease Producing Bacteria form Fish Sauce Samples
Abstract:
Fermented fish samples from fish sauce factories in the eastern part of Thailand were used as sources for the isolation of salt-loving protease-producing bacteria. The conditions for optimal growth and salt-loving protease production were established for the extremely halophilic bacteria. Two hundred and eighty five strains of halophilic bacteria were isolated. Among these isolated strains, a totally ten strains of extremely halophilic bacteria exhibited the highest salt-loving proteases producing ability. Maximal growth and salt-loving proteases of these strain occurred in mM73 agar medium at 4M (24 %, w/v) NaCl. On the other hand, bacterial growth and salt-loving protease activity did not occur when NaCl concentration in mM73 agar medium was lowered to 2M (12 %, w/v). All of these strains were further secondary screened in liquid medium. These selected strains were cultured on a rotary shaker at 200 rpm at 37 ∞C in M73 liquid medium with 4M (24 %, w/v) NaCl at pH 7. The bacteria strain PB407 exhibited the highest salt-loving protease activity. In addition, the strain PB407 was identified and characterized. It was a Gram-negative, rod. The colonies were circle with red pigmentation. Growth occurred in a medium containing 17.5-25 % NaCl. Based on the data obtained in this study, it was concluded that the extremely halophilic bacteria strain PB407 belonged to the genus Halobacterium.
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