- Antimutagenicity of Phellinus linteus in Salmonella typhimurium
-
Shon, Yun Hee , Lee, Jae Sung , Lee, Hang Woo , Kim, Joong Wan , Lim, Jong Kook , Kim, Cheorl Ho , Nam, Kyung Soo
-
J. Microbiol. 1999;37(3):136-140.
-
-
-
 Abstract
 PDF
-
The mutagenicities and antimutagenicities of butanol (PL I) and water (PL II) extracts from the filtrate of the cultured broth of Phellinus linteus were examined using the Ames/Salmonella test. No mutagenic activity of PL I and PL II was found in Salmonella typhimurium strains TA98 and TA100, either with or without S9 activation. In contrast, PL I and PL II showed inhibitory effects on the mutagenic activities induced by the directly-acting mutagens, 4-nitro-o-phenylenediamine (NPD) using the tester strain TA98 and sodium azide (NaN₃) using the tester strain TA 100 in the absence of S9 mix. PLI and PL II also showed inhibitory effects on the mutagenicities of the indirectly-acting mutagens, 2-aminofluorene (2-AF) using the tester strain TA98 and benzo[a]pyrene (B[a]P) using the tester strain TA 100 in the presence of S9. These results suggest that P. linteus has an antimutagenic activity and may play a role in the prevention of cancer.
- Genomic polymorphism in clinical mycobacterial strains analyzed by pulsed-field gel electrophoresis
-
Kim, Jeong Ran , Kim, Cheorl Ho
-
J. Microbiol. 1997;35(3):172-176.
-
-
-
Abstract
PDF
-
The Mycobacterium tuberculosis clinical isolates in Korea, showing different drug resistances, were analyzed by comparing large restriction fragment (LRF) patterns produced y digestion of genomic DNA with infrequent-cutting endonucleases of SpeI, AsnI and pulsed-field gel electrophoresis (PFGE). SpeI and AsnI allowed with AsnI and SpeI, strains yielded an absolutely identical pattern for Korean type's mycobacteria even though they showed different drug resisstance. However, when three M. tuberculosis strains, showing drug resistance, were digested with XbaI, patterns were different from those of the other M. tuberculosis strians which are susceptible to drugs. This study reveals that the comparison of chromosomal restriction patterns is very useful as an additional aid for the differentiation and identification of M. tuberculosis strains showing drug resistances.
- A possible mechanism responsible for translocation and secretion an alkaliphilic bacillus sp. S-1 pullulanase
-
Shim, Jae Kyoung , Kim, Kyoung Sook , Kim, Cheorl Ho
-
J. Microbiol. 1997;35(3):213-221.
-
-
-
Abstract
PDF
-
The secretion of the alkaliphilic Bacillus sp. S-1 extracellular pullulanase involves translocation across the cytoplasmic membrane of the Gram-positive bacterial cell envelope. Translocation of the intracellular pullulanase PUL-I, was traced to elucidate the mechanism and pathway of protein secretion from an alkaliphilic Bacillus sp. S-1. Pullulanase could be slowly but quantitatively released into the medium during growth of the cells in medium containing proteinase K. The released pullulanase lacked the N-terminal domain. The N-terminus is the sole membrane anchor in the pullulanase protein and was not affected by proteases, confirming that it is not exposed on the cell surface. Processing of a 180,000M_r pullulanase to a 140,000M_r polypeptide has been demonstrated in cell extracts using antibodies raised against 140,000M_r extracellular form. Processing of the 180,000 M_r protein occured during the preparation of extracts in an alkaline pH condition. A modified rapid extraction procedure suggested that the processing event also occured in vivo. Processing apparently increased the activity of pullulanase. The western blotting analysis with mouse anti-serum against 140-kDa extracellular pullulanase PUL-E showed that PUL-I is processed into PUL-X via intermediate form of PUL-E. Possible explanationa for the translocation are discussed.
|
MSK
