Journal of Microbiology and Biotechnology
- Volume 6 Issue 6
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- Pages.381-385
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- 1996
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- 1017-7825(pISSN)
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- 1738-8872(eISSN)
A Plasmid of Lactococcus lactis subsp. lactis ML8 Linked with Lactose Metabolism and Extracellular Proteinase
- LEE, JONG-HOON (Department of Food Technology, Kyonggi University) ;
- HYONG JOO LEE (Department of Food Science and Technology and Research Center for New Biomaterials in Agriculture, Seoul National University)
- Published : 1996.12.01
Abstract
Three distinct plasmids, with approximate molecular weights of 1, 4.5, and 33 megadaltons, were found in Lactococcus lactis subsp. lactis (L. lactis) ML8. Slow acid-producing mutants of L. lactis ML8, isolated by plasmid curing with acriflavine treatment, lacked the 33-megadalton plasmids. The plasmid-cured mutant showed lactose-negative (Lac) characteristics and the alteration of extracellular proteinase pattern. The possible involvement of extracellular proteinase with the 33-megadalton plasmid is highlighted in this research.