• 한국식품영양학회지
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• 제9권4호
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• pp.509-515
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• 1996

Sour liquid 발효가 식빵의 제조조건과 품질에 미치는 영향을 알아보았다. Lactobacillus brevis와 Lactobacillus brevis와 Lactobacillus plantarum을 혼합 배양하면 sour dough bread 사용 유산균 중 산생성력이 가장 높았고 pH도 낮았다. Sour liquid 발효 제조시 제빵의 제조조건에 가장 적합한 배양조건, 배양온도, 시간 및 배지의 조서에 대해 실험하였다. L. brevis와 L. plantarum의 배양은 3$0^{\circ}C$에서 24시간 하였다. 배지조성 중 글루코오스를 2% 첨가하고 영양원으로서 yeast extract 0.4%를 첨가한 것의 결과가 가장 좋았다. Sour liquid ferments를 제빵제조시 중종 (sponge dough)에 넣었을 때 반죽의 pH를 4.64까지 낮추어 주어 발효력을 증가시켰고, total titratable acidity(TTA)도 보통 식빵의 0.46%보다 높은 0.54%를 나타내었다. 품질평가에 있어서, sour dough liquid를 이용한 식빵의 경우가 보통식빵보다 비용적 (specific volume)이 좋았다. 맛과 외형 특히 관능적인 품질(향취)이 증가되었다. 이는 유산균이 생성한 초산, 젖산 및 아미노산 등이 영향을 미치기 때문으로 보인다. 제품을 $25^{\circ}C$에서 6일 동안 저장하면서 노화도를 측정한 결과 보통식빵보다 노화지연에 훨씬 효과적으로 나타났고 Sour liquid ferments는 유산균 등이 생성한 유기산들이 곰팡이의 생육을 억제하여 제품의 저장기간이 연장되었다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVI)
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• pp.181-185
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• 2005

We investigated the fermentative production of lactic acid from cheese whey and corn steep liquor as cheap raw materials using Lactobacillus sp. RKY2 to reduce the manufacturing cost of lactic acid. Lactic acid yields were obtained at more than 0.98 g/g from medium containing whey lactose. Lactic aid productivities and yields obtained from whey lactose were slightly higher than those obtained from pure lactose. The final concentration of lactic acid increased with increase, in whey lactose concentration, whereas the lactic acid productivity decreased probably due to substrate inhibition. The fermentation efficiencies were improved by addition of more corn steep liquor to the medium.

• 한국미생물·생명공학회지
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• 제44권1호
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• pp.68-73
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• 2016

본 연구에서는 전국 가정집에서 제조한 김치로부터 분리한 유산균들 중에서 protease 활성 및 CPP 생산 능력이 가장 높은 균주인 strain 0301을 동정하였고 해당 균주의 특성과 CPP 생산 최적 조건을 조사하였다. 0301은 $0.6-0.8{\mu}m$ 크기의 gram 양성 구균이며, 16s rDNA 염기서열 분석 결과 Enterococcus faecalis MG-379로 동정 명명하였다. E. faecalis MG-379 균주를 2% fructose를 첨가하고 pH 6.0인 배지에서 37oC에서 36시간 배양하였을 때 CPP 생산 능력이 최대였으며, ICP를 이용하여 측정한 결과 2227.5 mg/kg으로, 비교 균주인 Enterococcus faecalis KCCM 40450에 비해 약 2배 가량 높은 CPP 생산 능력을 갖는 것으로 나타내었다.

• KSBB Journal
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• 제18권1호
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• pp.14-18
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• 2003

본 연구에서는 제지 슬러지를 이용한 SSF 공정에 L..paracasei KLB58을 적용하여 젖산과 더불어 생균제용 균체를 경제적으로 대량 생산하고자 하였다. KLB58의 배양온도와 섬유소 가수분해 효소인 $\beta$-glucosidase의 농도를 조절하여 최적의 생산 조건을 확인해 본 결과, 37$^{\circ}C$ 에서 2 unit/ml의 $\beta$-glucosidase를 첨가하여 배양하였을 때 최대의 젖산과 균체를 생산하였다. 또한 $\beta$-glucosidase를 포함하지 않아도 상대적으로 많은 양의 젖산과 균체를 생산하였으므로, 이에 대한향후 연구가 기대된다.

• Bulletin of the Korean Chemical Society
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• 제32권7호
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• pp.2418-2422
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• 2011

The enantiomeric separation of lactic acid for its absolute configuration has become important task for understanding its biological origin and metabolic process involved in the formation of lactic acid. It involves the conversion of enantiomers as diastereomeric O-pentafluoropropionylated (S)-(+)-3-methyl-2-butyl ester and the direct separation by gas chromatography-mass spectrometry on a achiral capillary column. The (R)- and (S)-lactic acids were completely separated with a high resolution of 1.9. The newly developed method showed good linearity (r ${\geq}$ 0.999), precision (% relative standard deviation = 3.4-6.2), and accuracy (% relative error = -7.7-1.4) with the detection limit of 0.011 ${\mu}g/mL$. When the method was applied to determine the absolute configuration of lactic acid in Lactobacillus delbrueckii subsp. lactis 304 (LAB 304), the composition (%) of (R)-lactic acid in the cell pellet and in the culture medium were $89.0{\pm}0.1$ and $78.2{\pm}0.4$, respectively. Thus, it was verified that the present method is useful for the identification and composition test of lactic enantiomers in microorganisms.

• International Journal of Advanced Culture Technology
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• 제3권2호
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• pp.100-109
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• 2015

Environmental problems from petroleum-based plastic wastes have been rapidly increasing in recent years. The alternative solution is focus on the development of environmental friendly plastic derived from renewable resource. Poly(lactic acid) (PLA) is a biodegradable polymer synthesized from biomass having potential to replace the petroleum-based non-degradable polymers utilizations. PLA can be synthesized by two methods: (1) ring-opening of lactide intermediate and (2) direct polycondensation of lactic acid processes. The latter process has advantages on high yields and high purity of polymer products, materials handling and ease of process treatments. The polymerization process of PLA synthesis has been widely studied in a laboratory scale. However, the mass scale production using direct polycondensation of lactic acid has not been reported. We have investigated the kinetics and scale-up process of direct polycondensation method to produce PLA in a pilot scale. The order of reaction is 2 and activation energy of lactic acid to lactic acid oligomers is 61.58 kJ/mol. The pre-polymer was further polymerized in a solid state polymerization (SSP) process. The synthesized PLA from both the laboratory and pilot scales show the comparable properties such as melting temperature and molecular weight. The appearance of synthesized PLA is yellow-white solid powder.

• 한국식품과학회지
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• 제33권6호
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• pp.676-681
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• 2001

분리대두단백을 단백분해효소로 처리하여 가수분해시킨 후 B. bifidum으로 단독배양하거나 B. bifidum과 L. acidophilus 또는 B. bifidum과 L. bulgaricus로 혼합배양하여 frozen soy yogurt를 제조한 다음 그 품질특성 및 관능적 특성을 측정하였다. 혼합배양시에 단독배양보다 생균수는 더 많았고 담즙산 내성은 더 우수하였으나 내산성은 큰 차이가 없었다. 그러나 ${\alpha}-chymotrypsin$으로 처리하고 B. bifidum과 L. bulgaricus 혼합배양한 시료가 비교적 내산성 및 담즙산 내성이 우수하였다. 시료의 overrun은 B. bifidum과 L. bulgaricus 혼합배양시에 ${\alpha}-chymotrypsin$ 처리군에서 가장 높았으며 아이스크림 제조기에서 30분 조작으로 73.45%를 형성하였다. ${\alpha}-chymotrypsin$ 처리군을 제외한 모든 시료에 있어서 단독배양시에 혼합배양보다 녹아내리는 정도가 더 컸다. 시료의 관능평가 결과 bromelain 처리군과 ${\alpha}-chymotrypsin$ 처리군의 경우 B. bifidum과 L. bulgaricus 혼합배양시에 단독배양보다 콩 비린내와 쓴맛은 적었고 신맛은 더 좋았으며 전반적으로 바람직하다고 평가되었다. 특히 ${\alpha}-chymotrypsin$ 처리군의 B. bifidum과 L. bulgaricus 혼합배양시에 신맛이 좋았고 쓰지 않았으며 떫지 않았다고 평가되어 가장 바람직하다고 평가되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제16권10호
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• pp.1550-1554
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• 2003

One hundred of lactic cultures were evaluated for their ability to inhibit hazardous microbes, such as Salmonella enteritidis, Salmonella typhimurium, Escherichia coli, Listeria monocytogenes, and Bacillus cereus by agar well diffusion method. None of them showed inhibitory halo against S. enteritidis, while 27 strains showed inhibitory activity against S. typhimurium, 6 against E. coli, 9 against ampicillin resistant E. coli, 31 against L. monocytogens, 10 against B. cereus. pH of the culture does not explain for the inhibitory activity except against B. cereus. A neutralized culture from corn silage showed highest inhibitory activity against S. typhimurium, and the size of inhibitory halo was same as 10 ug/mL of ampicillin. The culture was identified to be Lactobacillus buchneri on the basis of biochemical characteristics and utilization of substrates. Using the culture as probiotics could be expected to reduce antibiotics for animal feeding.

• Journal of Dairy Science and Biotechnology
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• 제18권1호
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• pp.47-60
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• 2000

Over decades of work, the probiotic research has grown rapidly with a number of new cultures, which is claimed a variety of benefit. However, many of the specific effects attributed to the ingestion of probiotics remain convoluted and scientifically unsubstantiated. Accordingly, the scientific community faces a greater challenge and must objectively seek cause and effect relationships for many potential and currently investigated probiotic species. Rational selection and design of probiotics remains an important challenge and will require a solid information about the physiology and genetics of candidate strains relevant to their intestinal roles, functional activities, and interaction of with other resident micro flora. As far as beneficial culture of lactic acid bacteria (LAB) is concerned, simple, cost-effective, and exact identification of candidate strains is of foremost importance among others. Until recently, the relatedness of bacterial isolates has been determined sorely by testing for one or several phenotyphic markers, using methods such as serotyping, phage-typing, biotyping, and so forth. However, there are problems in the use of many of these phenotype-based methods. In contrast, some of newer molecular typing methods involving the analysis of DNA offer many advantages over traditional techniques. These DNA-based methods have the greater discriminatory power than that of phenotypic procedures. This review focuses on the importance and the basis of molecular typing methods along with some considerations on de-sign and selection of probiotic culture for human consumption.

• 한국식품영양학회지
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• 제1권2호
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• pp.95-101
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• 1988

In order to produce lactic acid and calcium lactate very useful for foods and medical supplies, lactic acid fermentation was studied by Lactobacillus sporogenes, a spore forming lactic acid bacterium. When this bacterium was cultured aerobically in the spore forming medium, the spore forming rate was 96.0% as total cell number 20$\times$108/ml, spore number 19.2$\times$108/ml. One minute agitating every 1 hour in the flask culture, or agitation of 100rpm in the fermenter was most efficient to continue to ferment at 45$^{\circ}C$ for 4days in the fermentation medium containing 10% glucose as carbohydrate and CaCO3 as a neutralizing agent. This homofermentative lactic acid bacterium showed fermentation yield of 99.3% and more than 98.2% of the yield was L(+)-lactic acid.