• 한국해양학회지
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• 제4권1호
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• pp.36-48
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• 1969

The larvae of Mytilus coruscus were grown at the room temperature of approximately 15.1C under several different sulture conditions, i.e., salinity, population of the larvae, density and kind of food organisms, etc. (1) The egg of Mytilus coruscus obtained in the laboratory measured about 73.0${\mu}$ in diameter. The embryos gradually developed into larvae up to 179.0${\mu}$ shell length with the shell height of 135.9${\mu}$ even in the absence of the algal food. Beyond this size, however, the growth of larvae was considerably retarded, indicating that the better growth could be expected if the food began to be fed four days after spawning. (2) The larvae began settling upon reaching 281.4${\mu}$ to 310.9${\mu}$ in shell length or 264.3${\mu}$ to 301.9${\mu}$ in shell height. When the shell length reaches 322.6${\mu}$ to 337.1${\mu}$, the shell height also reaches about the same, i.e., 321.5${\mu}$ to 346.2${\mu}$. (3) Daily rate of food consumption was determined by the size of the larvae and the species of the algal food. Regardless of the species of food given, the rage of food consumption remained almost the same until the larva reached the straight-hinge stage, and marked variations were found as the larvae grew larger. Daily rate of food consumption was shown as follow; Chaetoceros calcitrans : Y=2.99167e$\^$0.000018243x$\^$2// Cyclotella nana : Y=3.00324e$\^$0.000015481x$\^$2// Monochrysis lutheri : Y=3.000056e$\^$0.000014485$\^$2// (4) Suitable amount of the food to be given was about five times of the consumed food by Mytilus coruscus. (5) When the numbers of the larvae was higher than ten per milliliter, the growth was significantly retarded. (6) Monochrysis lutheri and Cyclotella nana were much better than Chaetoceros calcitrans as the food of Mytilus coruscus, and even the same food organism showed some difference with the age of the organism. (7) Sea water of higher salinity showed the better result in the growth of the larvae and the water with the specific gravity of 1.020 or below was dangerous for the larvae. (8) The mean growth of the larvae of Mytilus coruscus under lavorable condition was shown as follows: shell length 121.8${\mu}$ to 179.0${\mu}$ : Y=119.18+7.42X 196.7${\mu}$ to 322.6${\mu}$ : Y=203.144+7.687X 322.6${\mu}$ to 985.1${\mu}$ : Y=302.5978+11.8356X shell height 86.3${\mu}$ to 135.9${\mu}$ : Y=86.22+6.40X 158.1${\mu}$ to 321.5${\mu}$ : Y=162.998+10.027X 321.5${\mu}$ to 1,215.4${\mu}$ : Y=309.3701+16.258X Relationships between the shell length and shell height were shown as follows: shell length 121.8${\mu}$ to 179.0 : Y=0.83726X-15.79165 196.7${\mu}$ to 322.6 : Y=1.29909X-100.58610 322.6${\mu}$ to 985.1${\mu}$ : Y=1.3536X-101.6806

• 한국식품과학회지
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• 제3권1호
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• pp.68-77
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• 1971

전국 각지에서 수집한 토양을 비롯한 기타 시료로부터 배양액중에 lysine을 생산 축적하는 미생물 94주를 분리하여 이를 다시 비교 검토함으로써 lysine생산이 2 mg/ml 이상인 균주 6주를 선정하고 균학적 성질을 조사한 결과 Micrococcus 속 1주, Corynebacterium 속 3주, Brevibacterium 속 2주였다. Corynebacterium sp. 1주 (S-27-12)에 대한 합성 배지에서의 lysine 축적조건을 검토한 결과 glucose 7.5%, urea 0.6%, $KH_2PO_4\;0.2%$, $Na_2HPO_4\;0.05%$, $MgSO_4{\cdot}7H_2O\;0.03%$, $MnSO_4{\cdot}4H_2O\;0.001%$, $FeSO_4{\cdot}7H_2O\;0.0005%$, pH 7.2가 최적이었으며 이 때의 lysine 생산량은 4mg/ml 정도였다.

• Journal of Microbiology and Biotechnology
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• 제24권2호
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• pp.270-279
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• 2014

Microbial community shifts, associated with performance data, were investigated in an anaerobic batch digester treating high-solid food waste under mesophilic conditions using, a combination of molecular techniques and chemical analysis methods. The batch process was successfully operated with an organic removal efficiency of 44.5% associated with a biogas yield of 0.82 L/g $VS_{removal}$. Microbial community structures were examined by denaturing gel gradient electrophoresis. Clostridium and Symbiobacterium organisms were suggested to be mainly responsible for the organic matter catabolism in hydrolysis and acidogenesis reactions. The dynamics of archaeal and methanogenic populations were monitored using real-time PCR targeting 16S rRNA genes. Methanosarcina was the predominant methanogen, suggesting that the methanogenesis took place mainly via an aceticlastic pathway. Hydrogenotrophic methanogens were also supported in high-solid anaerobic digestion of food waste through syntrophism with syntrophic bacterium. Microbial community shifts showed good agreement with the performance parameters in anaerobic digestion, implying the possibility of diagnosing a high-solid anaerobic digestion process by monitoring microbial community shifts. On the other hand, the batch results could be relevant to the start-up period of a continuous system and could also provide useful information to set up a continuous operation.

• 한국식품영양과학회지
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• 제17권4호
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• pp.342-347
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• 1988

김치 제조시 김치의 발효에 관하여는 유산균을 starter로 첨가하여 발효를 촉진시키고 품질을 갖는 김치 제조의 가능성을 알아보기 위해 starter첨가가 김치의 숙성에 미치는 효과를 검토한 결과 김치 발효의 주 유산균인 Lactobacillus plantarum, Lactobacillus brevis, Pediococcus cerevisiae, Leuconostoc mesenteroides의 4종류의 균주를 사용하여 단독및 혼합하여 첨가한 결과 4균주를 동일 비율로 배추량의 3% 첨가한경우 숙성을 측진시키는 경향을 나타내었으며 부재료중 고추가루는 김치의 숙성을 촉진시켰으며 생강은 starter의 초기성장을 억제시키는 경향을 나타내었다. Starter를 사용하여 김치를 제조한 경우 숙성 기간이 약 24시간 단축되었으며 기호성에 있어서도 무첨가구에 비해 전반적으로 양호하였고 특히 향이 가장 양호 하였다.

• Fisheries and Aquatic Sciences
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• 제10권3호
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• pp.113-118
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• 2007

Bromophenols are a group of compounds found only in marine organisms. They accumulate and give a sea-like aroma to marine animals. Cultivated fishes generally contain low concentrations of bromophenols compared to wild fishes. Feeding cultivated fishes with bromophenol-containing seaweed could increase their bromophenol content and thus improve their flavor quality. We evaluated the effect of an experimental feed on the bromophenol content of green grouper, Epinephelus coioides, during an 8-week feeding period. Green grouper individuals were divided into two groups and fed with conventional feed or experimental feed containing dried seaweed. Fish were collected biweekly for 8 weeks for proximate analyses and bromophenol content evaluations. Bromophenols were extracted, identified, and quantified by gas chromatography-mass spectrometry. Both moisture and lipid contents were generally higher in the controls; however, total weight and protein content were higher in the experimental group. Only 2,4-dibromophenol and 2,4,6-tribromophenol were detected in the samples. Throughout the 8 weeks, 2,4,6-tribromophenol concentrations were higher in the experimental group (9.20-32.3 ng/g dry wt) than in the control group (7.33-18.79 ng/g dry wt), but no significant difference in 2,4-dibromophenol concentration was detected between the two groups. The total bromophenol content reached a maximum at week 4 for the experimental feed and week 6 for the control. In short, experimental feed that incorporated bromophenol-containing seaweed increased the total bromophenol content in the green grouper.

• Food Quality and Culture
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• 제2권1호
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• pp.55-60
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• 2008

This study examined the effects of lactic acid spray, hot water spray, or their combined treatment, as well as the effects of acidified sodium chlorite (ASC), for the decontamination of Escherichia coli on beef carcass surfaces using a commercial intervention system. With this system, the effects of 2 or 4% lactic acid (v/v), hot water ($89{\pm}1^{\circ}C$), or their combined treatment, were examined in terms of reducing inoculated E. coli. ASC (266 ppm), which was adjusted to pH 2.5 using acetic acid or citric acid, was applied using a hand-held spray system. When the beef carcasses were treated with 2 or 4% lactic acid for 10.4 s, less than 1 log reductions of inoculated E. coli were observed. A hot water spray treatment for 9.8 s resulted in a 2.1 log reduction of inoculated E. coli. However, when the hot water was followed with either 2 or 4% lactic acid, no difference in E. coli reduction was found between the hot water alone or the combined treatment with lactic acid. When ASC was adjusted to pH 2.5 with acetic acid and citric acid, 3.8 and 4.1 log reductions of E. coli were observed, respectively. Overall, the lactic acid spray treatment was least effective, and the ASC treatment was most effective, for the E. coli decontamination of beef carcasses. Therefore, these data suggest that ASC would be a more effective intervention against E. coli than most of the methods currently being used. However, more research is required to evaluate the effects of ASC on other organisms, as well as to identify application methods that will not affect meat quality.

• 한국식품영양과학회지
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• 제13권1호
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• pp.117-126
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• 1984

Aflatoxins are toxic and carcinogenic secondary metabolites which are produced by trains of A. flavus and A. parasiticus during their growth on foods and feedstuffs. Aflatoxins are a group of closely related heterocyclic compounds of which $B_1$, $B_2$, and $G_2$ are the major members. Aflatoxins are synthesized via a polyketide pathway in which the general steps are acetate, an-thraquinones, xanthone and aflatoxins. Aflatoxin formation is favored by high moisture or high $a_w$(0.95${\sim}$0.99). The limiting $a_w$ for aflatoxin production on agricultural commodities is 0.83. Optimum temperature for aflatoxin production by the molds is $25{\sim}30^{\circ}C$ and the incubation time for the maximum production of the toxin is 7${\sim}$15 days. The limiting temperatures for aflatoxin production are ${\leq}7.5^{\circ}C\;and\;\geq40^{\circ}C$. Cycling temperatures may or may not stimulate aflatoxin production depending on the amplitude of cycling, substrate and strains of molds. Aflatoxin pro-ducing molds are aerobic organisms and thus have a requirement for oxygen. A decreasing $O_2$ concentration and/or increasing concentrations of $CO_2$ or $N_2$ depress the mold growth and aflatoxin formation. A. flavus grows competitively or associatively in the presence of other microorganisms and occasionally loses the competition with other microorganisms. Some lactic acid bacteria have been shown to reduce growth and aflatoxin production by A. parasiticus. Carbon source is the most important nutritional factors affecting aflatoxin formation by the molds. Sucrose, fructose and glucose are the most favorable carbon sources. Food substrates of plant derived products which have high carbohydrate content such as agricultural commodities and their products are most vulnerable to contamination by aflatoxins.

• 한국식품영양과학회지
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• 제25권5호
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• pp.804-809
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• 1996

식품위생 관련 미생물 8종에 대한 방사선 단독 및 가열처리와의 병용처리에 의한 살균효과를 조사한 결과, 방사선 단독처리시는 공시균주들의 D$_{10}$ 값은 0.14~0.48 kGy로 나타났으며 그 중 Escherichia coli가 0.14 kGy로 감수성이 가장 높았다. 불활성화 계수는 2~3 kGy 조사시 4.54~21.43으로 나타났다. 가열 단독 처리시에는 D(min) 값이 $50\pm1^{\circ}C에서$ 는 10~40분, $60\pm1^{\circ}C에서는$ 5~15분 정도로 나타났다. 가열과 방사선과의 병용처리시는 D$_{10}$ 값이 0.04~0.31 kGy의 범위로 나타났고 불활성화 계수도 2~3 kGy 조사시 에는 6.45~75로 나타났다. 이상의 결과, 가열과 방사선의 병용처리는 균주들의 방사선 감수성을 현저하게 상승시킴을 알 수 있었다.있었다.

• 동아시아식생활학회지
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• 제14권4호
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• pp.363-369
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• 2004

Three different doengjang(fermented soybean paste) were prepared by using B. subtilis SS103 with high angiotensin converting enzyme(ACE) inhibitory activity, Asp. oryzae and mixed culture of two organisms, respectively. Quality characteristics and the inhibitory activity were compared. $\beta$-Amylase activity rapidly increased during 30 days of fermentation, but lower activity was found in doenjang prepared with B. subtilis. However, $\alpha$-Galactosidase activity decreased for 15 days of fermentation and little activity was observed after that fermentation period. Protease production tended to increase during the fermentation. High protease activity was found only in doengjang prepared with Asp. oryzae, but the doengjang prepared with B. subtilis SS103 showed very low activity. Total isoflavone content at 90 day fermentation was the highest in doengjang prepared with mixture of Asp. oryzae and B. subtilis. ACE inhibitory activity increased during the fermentation period. The highest activity was found in doengjang made with mixture of Asp. oryzae and B. subtilis. Sensory evaluation on doengjang itself and its soup indicated that doengjang made with mixture of Asp. oryzae and B. subtilis showed higher acceptability on taste, flavor and color than those prepared with only Asp. oryzae or B. subtilis, respectively.

• 한국식품과학회지
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• 제50권6호
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• pp.581-586
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• 2018

본 연구에서는 서울과 경기도 지역 소매점 및 대형마트에서 판매되고 있는 샐러드, 어린잎, 새싹채소로부터 Enterococcus의 존재를 파악하고 9개 항생제에 대한 항생제 저항성 프로파일을 확보했다. Quinupristin/dalfopristin에 저항성을 가지는 분리주가 85.0%에 이르렀고, 특히 E. faecalis 분리주는 18종 중 17종이 저항성을 나타냈다. 또한 critically important 항생제 중 highest priority로 분류되는 ciprofloxacin과 erythromycin에 대해 각각 40.0, 50.0%가 중간 정도의 저항성을 보였으며, vancomycin에 대한 저항성을 가지는 분리주는 검출되지 않았다. Enterococci의 항생제 저항성 정도는 식품 안전뿐만 아니라 공중 보건에 있어서도 중요하다는 측면에서 본 연구의 Enterococcus 오염 정도, 항생제 내성율에 대한 결과는 향후 신선 편이식품 섭취가 인체 건강에 미치는 위험분석을 위한 기초자료로서 유용한 정보를 제공할 것으로 보이며 앞으로 특별한 열처리 없이 섭취하는 신선 편이식품에 대한 지속적인 모니터링이 필요할 것이라 사료된다.