Production of alkaline protease by the moderate halophile, Halomonas sp. ES 10

Halomonas sp. ES 10에 의한 alkaline protease의 생산

A moderate halophile, ES 10 which produces a high level of alkaline protease was isolated from the salted anchovies and indentified as a strain of Halomonas sp. The optimum growth of the Halomonas sp. was revealed in the presence of 2 M NaCl and its growth rate in the Temporary Synthetic Medium was increased by adding DL-alanine, but inhibited by adding L-proline. The concentration of $Na^+$, $K^+$ and $Mg^{2+}$ in the cell mass of the Halomonas sp. ES 10 was 5-, 25- and 35-fold higher by dry weight basis, respectively than those of B. subtilis or E. coli. Norberg and Hofsten medium with 1 M NaCl was selected as the best medium for producing high level of alkaline protease. The optimum temperature for the growth and protease production was equally $20^{\circ}C$.

무염조건에서는 생육할 수 없고 2 M의 NaCl 존재하에서 가장 잘 생육하는 중도 호염성균이며 alkaline protease를 생산하는 ES 10균주를 멸치젓에서 분리하여 Halomonas속 균으로 동정하였다. 이 균은 합성배지인 TSM배지에 DL-alanine의 첨가로 생육이 촉진되고 L-proline의 첨가로 생육이 저해되었다. 이 균의 세포내 $Na^+$함량은 Bacillus subtilis나 E. coli보다 5배 정도 많았으며 $K^+$함량은 25배, $Mg^{2+}$함량은 38배 정도 많았다. 이 균의 Protease 생산은 NaCl 1 M첨가된 Norberg와 Hofsten배지에서 $20^{\circ}C$로 배양했을 때 가장 양호하였다.