FACTORS AFFECTING THE FORMATION OF SOLUBLE GLUCAN BY LACTOCOCCUS LACTIS 1370

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Journal of the Korean Academy of Pediatric Dentistry 2000;27(2):185-191.
Published online May 31, 2000.

FACTORS AFFECTING THE FORMATION OF SOLUBLE GLUCAN BY LACTOCOCCUS LACTIS 1370

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유산구균 1370의 수용성 글루캔 형성에 영향을 미치는 인자

오인근¹, 양규호¹, 정진², 오종석²

¹전남대학교 치과대학 소아치과학교실
²전남대학교 의과대학 미생물학교실

Abstract

The water-soluble glucan produced by Lactococcus lactis 1370 affects the formation of dental plaque by Streptococcus mutans. In this study the factors affecting the formation of water-soluble glucan were assessed as the optical density of culture supernatant of Lactococcus lactis 1370 in the spectrophotometer. 1. The optical density of culture supernatant was high when Lactococcus lactis 1370 was cultured in M17 broth with 5% sucrose, while being low in culture supernatant of Streptococcus mutans. 2. The optical density of culture supernatant was higher when Lactococcus lactis 1370 was cultured in M17 broth with 10% sucrose than when being cultured without sucrose (p<0.05), and was higher at pH 7 than pH 5 (p<0.05). 3. The optical density of culture supernatant was the highest at 37℃ among 32℃,37℃ and 42℃, and was higher in the anaerobic incubator than in the aerobic incubator (p<0.05). 4. The optical density of culture supernatant was the highest in the media containing 1.0mM CaCl₂ (p<0.05), 2.5mM KCl (p<0.05), and 1.6mM MgCl₂. 5. When Streptococcus mutans was cultured in the media containing a quarter culture supernatant of Lactococcus lactis 1370 grown in M17 broth, the mean weight of produced artificial plaque was 103.0mg on the wire, whereas being significantly reduced to 5.6mg in the media containing a quarter culture supernatant of Lactococcus lactis 1370 grown in M17 broth containing 5% sucrose (p<0.05). These results indicate that the water-soluble glucan is more formed by Lactococcus lactis 1370 in the media containing sucrose or under the adequate conditions for the growth of bacteria, and inhibits the formation of artificial plaque by Streptococcus mutans.