• Journal of Applied Biological Chemistry
• /
• v.48 no.2
• /
• pp.75-78
• /
• 2005

Halotolerant protease produced by Halomonas marisflava KCCM 10457 was partially purified through ammonium sulfate precipitation and Sephacryl S-200HR gel permeation chromatography. Optimal pH and temperature of protease were 11.0 and $45^{\circ}C$, respectively. Enzyme activity was inhibited by $Cu^{2+}$, $Hg^{2+}$, $Fe^{2+}$, and $Fe^{3+}$, and selectively inhibited by p-chloromercuribenzoic acid (PCMB), suggesting this enzyme is cysteine protease. The enzyme is halotolerant, because it retained 77% of original activity in presence of 3.33 M NaCl. The protease showed broad substrate specificity to various natural proteins; BSA, casein, egg albumin, gelatin, and hemoglobin.

• Journal of Life Science
• /
• v.16 no.1
• /
• pp.120-125
• /
• 2006

To isolate and identify histamine degrading bacteria from Kwamegi, bacteria were screened with restriction media containing histamine. Ten strains were selected through morphological and biochemical identification procedure followed by comparison with DNA sequence of 16 rRNA gene. And also, these strains were confirmed by the histamine degrading assay such as turbidity and enzymatic assay. The results of identification are as followings : Ewingella americana B791, Arthrobacter sp. R45S, Halomonas marisflava, Psychrobacter sp. 9B-7, Bacillus sp. LMC 21002, Psychrohacter cibarius BC-220, Bacillus megaterium KL-197 were identified showing homology of $99\%,\;95\%,\;98\%,\;99\%,\;99\%,\;99\%\;and\;98\%$, respectively. Three strains remain unidentified. Arthrobacter sp. R45S, H. marisflava, Bacillus sp. LMG 21002, B. megaterium KL-197 showed histamine degrading activity, whereas, Psychrobacter sp. 9B-7 only showed weak activity. Three unidentified strains also have histamine degrading activity. In contrast, E. american B791 and p. cibarius JG-220 did not show any significant activity of histamine degradation. The strains isolated from this study showed relatively fast growth rate and histamine degrading rate as compared to those from salted mackerel.