Article

Streptococcus thermophilus의 자연적 형질전환 메커니즘과 Leuconostoc 속 세균에서 그 메커니즘의 추론

박재용 *
Jae-Yong Park *
Author Information & Copyright
대구가톨릭대학교 식품영양학과
Department of Food Science and Nutrition, Catholic University of Daegu, Gyengsan 712-702, Korea
*Corresponding author: Jae-Yong Park, Department of Food Science and Nutrition, Catholic University of Daegu, Gyengsan 712-702, Korea. Tel: 82-53-850-3521, Fax: 82-53-850-3516, E-mail: jaepark@cu.ac.kr

Copyright © Korean Society for Lactic Acid Bacteria. All rights reserved. This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Published Online: Jun 30, 2019

Abstract

Natural genetic transformation is one of mechanism for horizontal transfer of genetic elements in bacteria which is an integral part of the physiology of bacteria. Streptococcus thermophilus utilize a novel quorum sensing system to control for development of natural competence which composes Rgg-type response regulator (ComR) and hydrophobic peptide pheromone (ComS). Matured ComS is released outside of cell during early exponential phase when growing in peptide free chemical defined medium (CDM). Matured ComS is transported via Ami (oligopeptide transport system) form outside to cytoplasm, and then bind to ComR. Activated ComR (matured ComS combining form of ComR) induces transcription of comX, which encodes an alternative sigma factor (σx) that regulates expression of late competence genes. Adding synthetic matured form of ComS to CDM, it can induce genetic transformation of S. thermophilus. The genus Leuconostoc has not been identified natural transformation mechanism even though presenting homologous genes related with late competence development. The study for identifying natural transformation mechanism of Leuconostoc can realize development of improved strains for kimchi industry.

Keywords: natural genetic transformation; Streptococcus thermophilus; Leuconostoc; kimch