• Korean Journal of Food Science and Technology
• /
• v.37 no.1
• /
• pp.61-66
• /
• 2005

Korean traditional rice wine Takju and Yakju were manufactured using 2-step-brewing method. To investigate microflora involved in fermentation step, number of microorganisms, pH, titratable acidity, and alcohol contents of Takju and Yakju were measured. In Takju and Yakju, although not significantly, $1.1{\times}10^{8}$ and $2.0{\times}10^{6}\;CFU/mL$ lactic acid bacteria at initial stage of second fermentation decreased to $8.3{\times}10^{6}\;and\;1.0{\times}10^{4}\;CFU/mL$ at the end of second fermentation, respectively. For Takju, micrococci and yeast occupied 80 and 20% at initial stage of second fermentation, whereas bacteria and yeast occupied 35 and 65% at the end of second fermentation, respectively. Yeast occupied 88% throughout the second fermentation of Yakju. The main yeast isolated from both Takju and Yakju was identified as Saccharomyces cerevisiae using API 20C AUX kit. The yeast strain Candida magnoliae was also detected during fermentation of Takju and Yakju.

• Journal of Life Science
• /
• v.31 no.5
• /
• pp.520-526
• /
• 2021

Microbial protein is one of the sources of protein in the rumen and can also be the source of glutamate production. Glutamic acid is used as fuel in the metabolic reaction in the body and the synthesis of all proteins for muscle and other cell components, and it is essential for proper immune function. Moreover, it is used as a surfactant, buffer, chelating agent, flavor enhancer, and culture medium, as well as in agriculture for such things as growth supplements. Glutamic acid is a substrate in the bioproduction of gamma-aminobutyric acid (GABA). This review provides insights into the role of glutamic acid and glutamic acid-producing microorganisms that contain the glutamate decarboxylase gene. These glutamic acid-producing microorganisms could be used in producing GABA, which has been known to regulate body temperature, increase DM intake and milk production, and improve milk composition. Most of these glutamic acid and GABA-producing microorganisms are lactic acid-producing bacteria (LAB), such as the Lactococcus, Lactobacillus, Enterococcus, and Streptococcus species. Through GABA synthesis, succinate can be produced. With the help of succinate dehydrogenase, propionate, and other metabolites can be produced from succinate. Furthermore, clostridia, such as Clostridium tetanomorphum and anaerobic micrococci, ferment glutamate and form acetate and butyrate during fermentation. Propionate and other metabolites can provide energy through conversion to blood glucose in the liver that is needed for the mammary system to produce lactose and live weight gain. Hence, health status and growth rates in ruminants can be improved through the use of these glutamic acid and/or GABA-producing microorganisms.

• Asian-Australasian Journal of Animal Sciences
• /
• v.23 no.7
• /
• pp.960-964
• /
• 2010

Water-cooked salted ducks were tray-packaged and stored under refrigeration ($4{\pm}1^{\circ}C$) in order to evaluate the quality changes during storage. pH, total volatile basic nitrogen (TVB-N), sensory and microbiological analysis were determined at 0, 2, 4, 6, 8, 9 and 10 days of storage. pH value and TVB-N (mg N/100 g) varied from $6.47{\pm}0.16$ to $6.69{\pm}0.10$ and from $5.90{\pm}0.93$ to $13.42{\pm}2.46$, respectively. Sensory results indicated that ducks were unacceptable at the 10th day of storage. The predominant spoilage bacteria at the end of the shelf-life were Brochothrix thermosphacta, lactic acid bacteria (LAB) and minor components were Enterobacteriaceae, members of Micrococci, yeasts and moulds. Pseudomonads were also detected. Both total bacteria and the various spoilage ones, overall, increased from the initial sampling to the final day.

• Asian-Australasian Journal of Animal Sciences
• /
• v.13 no.3
• /
• pp.376-380
• /
• 2000

This study was conducted to investigate protein and carbohydrate utilization of Micrococcus varians, Staphylococcus carnosus and Staphylococcus xylosus. Sensitivity to pH, sodium chloride, potassium sorbate and sodium nitrite of these strains was also determined. In Chinese-style beaker sausage manufacturing, the growth rate of these strains during the curing period ($20^{\circ}C$ and $30^{\circ}C$) was evaluated. The results indicated that no strains could hydrolyze azo-casein and sarcoplasmic protein and only S. xylosus could hydrolyze gelatin at $30^{\circ}C$. All of these strains could oxidize and ferment fructose and mannitol. S. carnosus and S. xylosus could slightly oxidize lactose and utilize citrate. Arabinose was oxidized by S. xylosus and sorbitol was oxidized by S. carnosus. Growth of M. varians was restricted at pH 5.0 and S. carnosus and S. xylosus were restricted at pH 4.5. S. xylosus and S. carnosus were able to grow with 0.1~0.5% potassium sorbate, 50~200 ppm sodium nitrite or 1~15% sodium chloride. S. xylosus had a higher growth rate than the other strains. Staphylococcus species grew well during curing period of Chinese-style beaker sausage then followed by Micrococcaceae.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
• /
• 1997.06a
• /
• pp.40-49
• /
• 1997

육제품 제조용 starter culture에 대한 연구는 기초과학을 바탕으로 관련 미생물의 생리대사 특성은 물론 이들의 환경적응성이나 상업적인 생산공정개발에 이르기까지 상당한 발전을 거듭해 왔다. 특히, 최근에 와서 유전공학의 응용으로 starter균주의 대사능력을 조절할 수 있고 생물학적 안전성을 쉽게 검증할수 있을 뿐만 아니라 원하는 활력을 안전하게 보존할 수 있도록 하는 연구도 진행되고 있다. 미생물의 생육환경인 육의 발효과정에 대한 연구를 통하여 육제품 starter culture개발의 근간이 되는 지식을 얻게 되었으며 어떤 요인이 발효과정중 starter 균주의 대사능력과 성장에 영향을 주는지 또한 발효과정중 starter culture간의 상호작용 및 starter와 윈래 혼합육에 존재하는 균들사이에서 일어나는 상호작용에 관한연구, 나아가서는 Bacteriocine과 Bacteriophage가 육제품제조에서 어떤 의미를 갖고 있는지 등에 관한 연구도 활발히 이루어지고 있다. 특히 이런 연구결과들을 통하여 이들 starter의 실제 상업적인 이용에 있어 원료육이나 부재료, 향신료의 선정은 물론 제조 공정을 제어하여 제품의 안전성을 기대할 수 있을 뿐만아니라 하나의 starter culture로 여러 종류의 발효sausage를 제조하여도 제품마다 최상의 능력을 발휘할 수 있는 새로운 균주의 개발에도 기여할 수 있다. 스타타컬쳐에 대한 연구상황은 균주별로 다르나 유산균에 대하여 가장 많이 연구되어 있고 Micrococci에 대한 연구도 상당히 진전되어 있다. 특히할만한 점은 아시아의 발효생선이 육제품 발효에 이용되는 Staphylococcus carnosus종의 habitat로 밝혀진 것이다. 뿐만 아니라 곰팡이 균주도 실제 praxis에 적합하게 개발시킬수 있다. 따라서 앞으로 발효육제품제조에 있어 starter culture가 갖는 의미는 매우 중요하며 특히 짧은 숙성기간을 거치는 발효소시지의 제조에 있어서는 필수불가결한 공정의 한 분야로 자리잡게 될 것이다.

• Journal of Environmental Health Sciences
• /
• v.11 no.2
• /
• pp.41-54
• /
• 1985

This study was conducted for the improvement of milk quality and milk hygiene in public health point of view. Investigation of mastiris infection rate, isolation and identification of causative microorganisms in CMT positive milk, investigation of milk contamination level by measuring the bacteria and soma tic cell counts and investigation of dairy management in farms were performed on 1.605 quarters milk of 434 cows of 20 dairy farms in Gyunggi-area from September 1983 to March 1984. The results were summarized as follows 1. Sixteen (3.7%) of 434 cows were found to be infected with clinical mastiris. 234 (53.9%) of 434 cows and 608(37.9%) of 1, 605 quarters were found to be infected with subclinical mastiris. 2. The causative microorganisms isolated were Staphylococcus aureus (38.3%), Staphylococcus epidermidis(21.0%), Micrococci(13.6%), Streptococcus spp. (12.3%), E. coli (7.4%), Fungus & Yeast (1.6%) and others (5.8%). 3. Total numbers of bacteria were $9.2{\times}10^6$ to $1.21{\times}10^7/ml$(av. $1.805{\times} 10^7/ml$), numbers of coliform bacteria were $4.1{\times} 10^5$ to $9.4{\times} 10^5$/ml(av. $7.05{\times} 10^5$/ml) and somatic cell counts were $4.8{\times} 10^5$ to $1.52{\times} 10^6$ cells/ml (av. $9.5{\times} 10^5$cells/ml) in bulk milk. 4. As comparing with CMT score of +, ++ and +++, somatic cell counts were $3.4{\times} 10^5$ to $1.64{\times} 10^6$ cells/ml (av. $6.41{\times} 10^5$cells/ml), $5.4{\times} 10^5$ to $2.75{\times} 10^6$ cells/ml(av. $1.762{\times} 10^6$cells/ml) and $1.97{\times} 10^6$ to $9.75{\times} 10^6$ cells/ml(av. $7.781{\times} 10^6$cells/ml), respectively. 5. In investigation on dairy management, performance of dry cow therapy, teat dipping after milking, disinfection of milking machine at every milking, replacement of milk liner within 6months and opportunity of acquirement for the mastiris control techniques by dairy education were 65%, 40%, 45%, 55% and 50% in 20 dairy farms, respectively.