• The Korean Journal of Zoology
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• v.33 no.1
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• pp.53-62
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• 1990

Fully grown amphibian oocytes undergo their maturation (germinal vesicle breakdown, GVBD) during in vitro follicle culture when they are stimulated with frog pituitary homogenate (FPH) or progesterone. Present experiments were designed to determine whether proteolytic enzymes are involved in the regulation of the matunation process. Treatment of a $\alpha$ -chymoiyypsin inhibitor, N a -tosyl-L-phenylalanine-chloromethyl-ketone(TP) to the oocytes exhibited a biphasic phenomenon, the induction of the maturation without added hormone at relatively low doses (0.001-1 $\mu$M) and inhibition of the hormone induced oocyte maturation at a high dose (100 $\mu$M). Treatment of a trypsin inhibitor, N a -tosyl-L-lysine-chloromethyl ketone(TLCK) to the oocytes did not induce the maturation, but rather suppressed the hormone induced oocyte maturation in a high dose(100 $\mu$ M). Treatment of exogenous iyypsin to the oocyte induced their maturation without added hormone in a dose dependent manner (0.001-1 $\mu$ M). The data presented here indicate that some proteolytic enzymes play a role in the regulation of the maturation(meiotic arrest or reinitiation) in amphibians.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.6
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• pp.903-911
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• 2011

In this study, Bacillus polyfermenticus CJ6 harboring antibacterial activity was isolated from meju. The antibacterial activity of Bacillus polyfermenticus CJ6 was stable in the pH range of 3.0~9.0, but it disappeared after culture at $70^{\circ}C$ for 24 hr. Antibacterial activity was inactivated by proteinase K, protease, and ${\alpha}$-chymotrypsin, indicating its proteinaceous nature. The growth inhibitory effects of B. polyfermenticus CJ6 culture on food-borne pathogens such as Staphylococcus aureus, Salmonella Typhi, Listeria monocytogenes, and Escherichia coli O157:H7 were examined in this study. Approximately 6~6.2 log CFU/mL of each pathogen was co-cultured with B. polyfermenticus CJ6 in a 50 mL culture volume for 24 hr. Growth of S. aureus and L. monocytogenes was completely inhibited after 3 hr of incubation. Growth of S. Typhi and E. coli O157:H7 was also completely inhibited after 6 hr of incubation. The antibacterial compounds from B. polyfermenticus CJ6 were purified by solid phase extraction (C18 Sep-pak cartridge), recycling preparative HPLC, and analytical HPLC. Ultra-high performance liquid chromatography and electrospray ionization tandem mass spectrometry analysis were used to identify the purified antibacterial compounds, which were confirmed to be five peptides (757.4153 Da, 750.3444 Da, 1024.5282 Da, 1123.6083 Da, and 1617.8170 Da).