Bài báo khoa học

Gelatinase is an extracellular metalloproteases capable of hydrolyzing gelatine, collagen, elastin, etc., which is used in processing industries, food technology and research. In this study, two hundred of sixteen bacterial isolates from fish diseases were examined for their ability to produce gelatinase. Results showed that eleven strains (5.09%) of gelatinase active bacteria were selected. Gelatinase activity ranged from 0.3 to 0.64 U/ mL, in which the strain MD4 showed the highest gelatinase production capacity of 0.64 ± 0.11 U/mL. Strain MD4 grew in the range of temperature from 25-45°C (optimum at 37°C), pH 4-10 (optimum at pH 7), and NaCl concentration from 0,5 to 5% (optimum at 4%). Strain MD4 was characterized as Gram-positive, spheroidal, non-spore-forming, non-spore organism. Hence, strain MD4 was selected and identified by phylogenetic analysis of 16S rRNA gene sequence. The 16S rRNA sequence of strain HDL17 (GenBank accession No. MG982575.1.) shared 99% identity with Enterococus faecalis NBRC 100480.