우유항생물질을 해부한다

강국희,Gang, Guk-Hui 한국유가공협회 1995 牛乳 Vol.63 No.-

MBC의 무책임한 보도와 이에 편승한 파스퇴르의 이기적인 비방광고로 고름우유 파동이 사회문제화 되자 우유전문가이며 세균학자인 강국희 교수는 학자적 양심으로 그 진상을 정확히 규명해 진정시키고자 ‘고름우유란 없다’는 장문의 글을 발표하고 본지에도 기고했다. 그 후 11월 20일 보건복지부에서 시판 우유 중 5개 제품에서 인체에는 해가 없는 극미량지만 항생 · 항균물질이 검출됐다고 발표해 그 파장이 커지가 그 실상을 밝히기 위해 ‘우유항생물질을 해부 한다’는 글을 추가로 발표했다. 본지는 이를 발췌하여 게재했다.

한국산 원유의 화학적 조성에 관한 연구 - 지역별 , 계절별

강국희,고준수,김영교,김영주,김종우,김현욱,박종래,유제현,윤여창,윤영호,이현종,임종우 ( Kook Hee Kang,Jun Soo Goh,Young Kyo Kim,Young Joo Kim,Jong Woo Kim,Hyun Uk Kim,Jong Rae Park,Jae Hyun Yu,Yoh Chang Yoon,Young Ho Yoon,Hyun Jong Lee,Jo 한국낙농학회 1991 韓國酪農學會誌 Vol.13 No.1

Phage耐性突然變異菌의 生育에 관한 연구

姜國熙 成均館大學校 1982 論文集 Vol.32 No.-

A comparative study has been made of growth of L. casei YIT 9018 being used as the starter of fermented milk and the phage insensitive strains obtained by treating L. casei YIT 9018 with Nitrosoguanidine. The results of cultivation parent strain YIT 9018 and 8 strains of phage insensitive stain in skimmilk at 37 C for 30 days has shown that the variables of their viable cells are nearly identical. In order to determine whether these strains are safe against frozen storage their viable cells were counted during 60 day storage at 150C. The result of the study has shown that viable cells remained nearly identical with the level of their unfrozen state. The results of examining the mean generation time of YIT 9018 and pr 38 strain is as follows: the mean generation time of YIT 9018 was 67 minutes in MRT broth and that of YIT 9018 was 86 minutes in skimmilk, while that of PR 38 recorded 63 minutes and 77 minutes in MRT broth and skimmilk respectively.

GOS가 장내 Bifidobacteria의 생육촉진에 미치는 영향에 관한 연구

강국희,문지웅,강대중,이재영 成均館大學校 科學技術硏究所 1993 論文集 Vol.44 No.2

We investigated the growth effect of various sugars on the principal intestinal microorganisms which were Bifidobacteria, Lactobacilli, Streptococci, Clostridia, Escherichia, Eubacteria, and Staphylococci. Those microorganisms were cultivated on media containing various sugars. The sugars were grouped into A, B, and C. Group A consisted of sugars extracted by water, 5%, 15%, 30%, and 40%, EtOH, respectively. Group B were galactooligosaccharide(GOS), fructooligosaccharide(FOS), isomaltooligosaccharide(IMO), and xylooligosaccharide( XOS). Group C were LOS, SOS, and LSOS. Bif. adolescentis, Bif. bifidum, Bif. infantis, Bif. longum, and Str. faecalis grew well on the media containing sugars of each A, B, and C group, while C. butyricurm, S. aureus, Eu. limosum, and E. coli did not. The results indicated that oligosaccharides of A, B, and C group were consumed effectively by Bifidobacterium spp. but not utilized by other intestinal microorganisms. Oligosaccharides of each A, B, and C group promoted selectively the growth of Bif. infantis and Bif. longum in the human intestinal microflora.

Limulus Amoebocyte Lysate법에 의한 원유와 살균유의 세균수 측정

姜國熙,王智怨,朴興洙,李圭鍾,金敬民 成均館大學校 科學技術硏究所 1993 論文集 Vol.44 No.2

LAL method for the determination of Gram-negative bacterial Lipopolysaccharides(LPS) in milk is proposed and its value for bacteriological quality control is investigated. The relationship between the LPS contents and total colony count(cfu/ml), which covers the Gram-negative bacteria, was determined in raw milk samples. The coefficient of correlation between Gram-negative bacterial counts(cfu/ml) and LPS contents was r^2 =0.969. And, the correlation coefficient between total bacterial counts(cfu/ml) and LPS contents was r^2 =0. 914. It was also investigated how much the LPS contents were in UHT milks from l0 different dairy industrial companies in Korea. It varied from 92 ng LPS/ml to 938 ng LPS /ml.

乳固形分의 농도에 다른 乳酸菌의 生育

姜國熙,李春花 成均館大學校 科學技術硏究所 1992 論文集 Vol.42 No.2

Influence of Solid-Not-Fat concentration on the growth of lactic acid bacteria was investigated in skim milk medium. The cultivation at optimum temperature of each strains was not significant with the various concentration of SNF 10%, 13%, 16%. The viable cell counts of Lac. bulgaricus and Lac. helveticus reached to maximum level of 10^9/ml in 24 hrs incubation and did not counted in 5 days incubation at 40℃. When the cultures (10^9/ml) stored at 30℃, viable cells remained 10^7-8/ml in 7 days. Survival of Lac. acidophilus culture was sustained high level at its optimum temperature for 7 days.

치이즈 Starter 로서의 Streptococcus faecalis var. liquefaciens 의 Proteinase Negative 균주

강국희,이명기 한국낙농학회 1987 韓國酪農學會誌 Vol.9 No.4

치이즈 starter로서 Streptococcus faecalis var. liquefaciens SKD-1014(Prt^-균주)의 이용 가능성은 다음과 같다. 1. 10% 탈지환원유에서 Prt^+ 균주가 Prt^- 균주에 비해 생균수는 5.6배, 산도는 7.9배, pH는 1.2가 낮았다. 2. 초기 응고시간을 효과적으로 감소시키는 Prt^- 균주의 접종량은 10^8 CFU/㎖이었다. 3. Tryptone이나 casamino acid를 10% 탈지환원유에 첨가하였을 때, tryptone을 첨가한 경우가 보다 빠르게 응고하였고, 첨가량은 0.5%가 효과적이었다. 4. Prt^+ 균주와 Prt^- 균주를 혼합배양하였을 때, Prt^+ 균주의 단백분해능은 Prt^- 균주의 성장을 촉진시켰으며, 초기 응고시간을 감소시키는 효과적인 혼합비는 Prt^+ 균주를 전체 접종량에 대하여 10%로 첨가하였을 때이다. 5. Prt^- 균주로 배양시킨 배양물에서는 서너개의 분해되지 않은 peptide의 band가 전기영동 gel 상에 나타났다. 6. 초기 응고된 침전물의 양은 Prt^- 균주로 배양한 배양물이 Prt^+ 균주의 것보다 많았다. This study was attempted to find out the possibility of use of Streptococcus faecalis var. liquefaciens SKD-1014 (Prt^- strain) as a cheese starter. The results obtained are summarized as follows: 1. Compared the Prt^+ strain with Prt^- strain in 10% reconstituted skim milk, the viable cell count was 5.6 times, acidity was 7.9 times, and pH was 1.2 unit lower. 2. When Prt^- strain was inoculated 108CFU/ml, it gave efficient reducing initial clotting time. 3. The Prt^- strain was more stimulated with trypton than that with casamino acid to coagulation in 10% reconstituted skim milk and 0.5% tryptone efficiently reduced the initial clotting time. 4. Prt^+ strain assisted Prt^- strain in coagulating work when mixtures of the two cell types were grown in 10% reconstituted skim milk, and significantly reduced the milk clotting time at which the proportion of Prt^+ cells was 10% to the total cells. 5. The cultured broth with Prt^- strain contained several undigested peptides which were developed on SDS-polyacrylamide gel. 6. The casein hydrolysates by Prt^- strain was more than that by Prt^+ strain when the culture broth was centrifuged at initial clotting time.

Str.thermophilus 510의 β-Galactosidase 유전자의 Cloning 및 대장균에의 발현

강국희,민해기,이호근,성문희 成均館大學校 科學技術硏究所 1992 論文集 Vol.42 No.2

Chromosomal DNA from Str. thermophilus 510 was purified and cleaved with the restriction enzyme PstI. Chromosomal DNA was ligated to pBR322 for transformation into E. coli JM109. A β-galactosidase positive clone was detected by its blue color on a medium supplemented with 5-bromo-4-chloro-3-indolyl-β-D-galactoside. This transformat possessed a single plasmid, designated pSK 001, which contained, in addition of the vector DNA, A 7.0Kb Pst I insertion fragment coding for β-gal activity. A restriction enzyme map of pSK 001 was consist of Hind Ⅲ, EcoR I, Bgl Ⅱ, Sal I, Pvu Ⅱ, etc. An extract from E. coli JM109 (pSK001) contained a β-gal protein with the same electrophoretic mobility as the β-gal from Str. thermophilus 510.

김치로부터 분리한 Pediococcus halophilus에 의한 α-Glucosidase의 생산

강국희,민해기,홍승표 成均館大學校 科學技術硏究所 1992 論文集 Vol.42 No.2

Six strains able to efficiently produce α-glucosidase were isolated from kimchi by enrichment culture in APT medium. Among them, Strain No.2 was found to have levels of α-glucosidase activity. The morphological, physiological and biochemical characteristics of the strain No.2 were studied according to the methods of Bergey's manual. Based on the results obtained in these experiments, Stain No.2 was identified to be a similar species to Pediococcus halophilus. The optima conditions for α-glucosidase production were cultured 0.5% starch, 0.4% yeast extract, 0.4% trypticase peptone, initial pH 7.5 at 37℃ and 24 hours cultivation.

당귀(Angelica acutiloba)와 감초(Glycyrrhizauralensis)의 열 추출액이 장내 세균의 성장에 미치는 효과

강국희,김경민,정재록 성균관대학교 생명과학자원연구소 1997 生命資源科學硏究 Vol.4 No.2

Bifidobacteriurn longum, Bifidobacterium adolescentis, Clostridium butyricum, Escherichia coli and Eubacterium limosum were cultured on the modified PYF medium containing 0.5% of glucose, heating extract(w/w) of Angelica acutiloba or Glycyrrhiza uralensis, and anaerobically incubated for 48hrs at 37℃. As a control, the same intestinal microorganisms cultured on the PYF medium with no additives and they were compared with other treatments. The addition of the heating extract of Angelica acutiloba increase the growth but optical density was lower than addition of glucose for the growth of intestinal microorgamisms which were investigated in this study. However, the heating extract of Glycyrrhiza uralensis slightly inhibited the growth for most intestinal microorganisms(Bif. longum, Bif. adolescentis, Cl. butyricum, and Eu. limosum) and it had a significant inhibition effect on the growth of Eu limosum when they were compared with control.