• Journal of Microbiology and Biotechnology
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• 제16권3호
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• pp.408-413
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• 2006

A strain, P821, with phospholipase D activity was isolated from soil and identified as a Streptomyces species. The phospholipase D enzyme was purified from a culture broth of the isolated strain using ammonium sulfate precipitation and DEAE-Sepharose, phenyl-Sepharose, and Superose 12 HR column chromatographies. The purified enzyme exhibited an optimum temperature and pH of $55^{\circ}C$ and 6.0, respectively, in the hydrolysis of phosphatidylcholine and remained stable up to $60^{\circ}C$ within a pH range of 3.5-8.0. The enzyme also catalyzed a transphosphatidylation reaction to produce phosphatidylserine with phosphatidylcholine and serine substrates. The optimum conditions for the transphosphatidylation were $30^{\circ}C$ and pH 5.0, indicating quite different optimum conditions for the hydrolysis and transphosphatidylation reactions. The gene encoding the enzyme was cloned by Southern hybridization and colony hybridization using a DNA probe designed from the conserved regions of other known phospholipase D enzymes. The resulting amino acid sequence was most similar to that of the PLD enzyme from Streptomyces halstedii (89.5%). Therefore, the enzyme was confirmed to be a phospholipase D with potential use in the production of phosphatidylserine.

• 한국잠사곤충학회지
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• 제24권1호
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• pp.32-38
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• 1982

본시험은 솔잎혹파리의 미생물학적 방제대책의 일관으로서 미생물의 분리동정과 병원성을 연구 조사하고자 행하여졌다. 1. 솔잎혹파리의 유충에서 분리동정 된 균은 Verticillium psalliotae, Aureobdsidium pullulansa, Streptomyces sp., Aspergillus sp.(2종), Ascochyt, sp.의 6종이었으며 6종 전부가 병원성이 있었다. 2. 추기 양잠농가로부터 Spicaria pracina, Isaria farinosa, Oospora destructor, Aspergillus oryzae, A. flavus의 5종의 누에 경화병균을 분리 동정하여, 솔잎혹파리유충에 대한 병원성을 검정한 결과, 5종 전부가 강력한 병원성을 나타내었다. 3. 솔잎혹파리 유충에서는 29종의 colony가 나타났으며 그 중에서 Bacillus 계통이 11, coccus 계통이 9개로 구분되었으며, 현재 병원성검정은 진행 중에 있으나 No.4와 No.9-1균주는 병원성이 인정되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제33권1호
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• pp.120-126
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• 2020

Objective: This study was conducted to determine the effects of dietary supplementation with Pediococcus acidilactici (P. acidilactici) ZPA017 as a probiotic on reproductive performance, fecal microbial flora and serum indices in sows during late gestation and lactation. Methods: A total of 94 sows (Large White×Yorkshire, average 4.50 parities) were randomly allotted to two dietary treatments: control diet and the diet supplemented with P. acidilactici ZPA017 (2.40×10⁹ colony-forming unit/kg of diets). The study started at d 90 of gestation and conducted until d 28 of lactation. Results: Compared to sows fed the control diet, supplementation of P. acidilactici ZPA017 increased the number of weaning piglets, weaning weight of litter and piglets, survival rate of piglets at weaning (p<0.05), and decreased diarrhea rate of piglets in lactation (p<0.05). Dietary P. acidilactici ZPA017 increased fecal Lactobacillus populations (p = 0.030) and reduced fecal Escherichia coli and Staphylococcus aureus populations (p<0.05) of sows at weaning. Moreover, the supplementation of P. acidilactici ZPA017 increased serum concentrations of immunoglobulin G, immunoglobulin A and total protein (p<0.05), while decreased serum haptoglobin concentration and alanine aminotransferase activity (p<0.05) of sows at weaning. Conclusion: Administration of P. acidilactici ZPA017 in diets during late gestation and lactation had positive effects on the reproductive performance, intestinal microflora balance and immunity of sows.

• 한국식품과학회지
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• 제27권1호
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• pp.63-67
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• 1995

닭 가공부산물의 재활용 가능성을 조사하기 위하여 부산물에 산을 첨가하여 자가분해(autolysis)시켰다. 자가분해 중 일어나는 pH와 지방산 조성변화 그리고 자가분해산물(autolysate)과 소피맥의 혼합과 혼합물 건조에 따른 일반성분과 미생물 총균수 변화를 조사하였다. 마쇄한 부산물의 초기 pH 6.52는 산 첨가 직후(5분 내) 2.75로 급격히 내려갔다가 자가분해 중 약간 증가해서 $3.06{\sim}2.92$를 유지하였다. 일반성분과 지방산 조성은 자가분해에 따른 영향을 크게 받지 않았으나 미생물 총균수와 진균수의 log CFU/g은 각각 7.45와 7.11에서 자가분해 후 3.39와 2.03으로 크게 줄어들었다. 자가분해는 닭 가공부산물의 사료자원화 가능성을 보여주었다.

• Journal of Microbiology and Biotechnology
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• 제27권2호
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• pp.226-233
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• 2017

Jeung-pyun, a fermented rice cake, is prepared by fermenting rice sourdough using makgeolli, a traditional Korean rice wine, in the presence of yeast and lactic acid bacteria (LAB). The goal of this study was to conduct biochemical and microbial analyses of five different rice sourdoughs, each fermented with a different commercial makgeolli, using culture-dependent and culture-independent approaches. All sourdough samples fermented with different makgeolli for 6.5 h showed different profiles in pH, total titratable acidity, organic acid concentration, and microbial growth. LAB belonging to different genera were identified based on colony morphology on modified MRS and sourdough bacteria agar medium. PCR-denaturing gradient gel electrophoresis analyses of the five sourdoughs showed different bands corresponding to LAB and yeast. 16S/26S rRNA gene sequence analyses of the samples confirmed that the predominant LAB in the five fermented rice doughs was Lactobacillus plantarum, Lb. pentosus, and Lb. brevis. Various other Lactobacillus spp. and Saccharomyces cerevisiae were common in all five fermented samples. This study provides comprehensive and comparative information on the microflora involved in fermentation of rice sourdough and signifies the need to develop effective starters to enrich the quality of jeung-pyun.

• Asian-Australasian Journal of Animal Sciences
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• 제31권12호
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• pp.1903-1912
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• 2018

Objective: To evaluate the effect of lactic acid bacteria and storage temperature on the microbial, chemical and mycotoxin composition of corn silage. Methods: Corn was harvested at 32.8% dry matter, and chopped to 1 to 2 cm. The chopped material was subjected to three treatments: i) control (distilled water); ii) $1{\times}10^6$ colony forming units (cfu)/g of Lactobacillus plantarum; iii) $1{\times}10^6cfu/g$ of Pediococcus pentosaceus. Treatments in triplicate were ensiled for 55 d at $20^{\circ}C$, $28^{\circ}C$, and $37^{\circ}C$ in 1-L polythene jars following packing to a density of approximately $800kg/m^3$ of fresh matter, respectively. At silo opening, microbial populations, fermentation characteristics, nutritive value and mycotoxins of corn silage were determined. Results: L. plantarum significantly increased yeast number, water soluble carbohydrates, nitrate and deoxynivalenol content, and significantly decreased the ammonia N value in corn silage compared with the control (p<0.05). P. pentosaceus significantly increased lactic acid bacteria and yeast number and content of deoxynivalenol, nivalenol, T-2 toxin and zearalenone, while decreasing mold population and content of nitrate and 3-acetyl-deoxynivalneol in corn silage when stored at $20^{\circ}C$ compared to the control (p<0.05). Storage temperature had a significant effect on deoxynivalenol, nivalenol, ochratoxin A, and zearalenone level in corn silage (p<0.05). Conclusion: Lactobacillus plantarum and Pediococcus pentosaceus did not decrease the contents of mycotoxins or nitrate in corn silage stored at three temperatures.

• 한국수산과학회지
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• 제55권5호
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• pp.662-669
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• 2022

The purpose of this study is to test the effects of electrolyzed water treatment on dried-laver Pyropia sp. processing facilities to control microbial contamination. Following the progression of the process to the next step, as well as during the lapse between process operating hours, the contamination level of total viable cell counts (TVC) and total coliform (TC) of laver increased. The TVC increased during the aging step, and after the molding-drying steps were completed, it increased by approximately 2.0 log CFU (colony forming unit)/g. Freshwater used for processing in April had a TVC of 4.31 log CFU/mL, which was more polluted than 2.61 log CFU/mL of seawater. Electrolyzed water was used to treat the sponge used in the laver-molding process, which resulted in a 2 log CFU/mL decrease.The TVC of dried-laver decreased by 1 to 2 log CFU/g when electrolyzed water was applied to the process. In conclusion, application of electrolyzed water in dried-laver processing was shown to be effective in reducing the microbiological contamination of the final product.

• 치위생과학회지
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• 제15권2호
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• pp.209-219
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• 2015

치주질환과 관련된 세균인 S. gordonii, F. nucleatum 및 P. gingivalis의 상호작용이 군집 형성에 미치는 영향을 알아보고자 trypticase soy hemin menadione broth에 단독 및 열처리한 사균과 혼합 분주하여 혐기성 균배양조를 통해 $37^{\circ}C$ $CO_2$ 배양기에서 anearobic gas pack 하에 7일간 배양하였다. 군집 형성 정도를 확인하기 위해 흡광도를 측정하였으며, 군집 구조 및 형태를 확인하기 위해 주사전자현미경으로 관찰하였다. P. gingivalis의 병원성에 미치는 영향을 확인하기 위해 real-time RT-PCR를 통해 gingipain인 HRgpA를 생성하는 rgpA 유전자에 대한 발현 분석을 시행하여 다음과 같은 결론을 얻었다. S. gordonii와 P. gingivalis의 군집 형성은 다른 사균들에 의해 증가하였다. F. nucleatum의 경우 P. gingivalis 사균에 의해 증가하는 양상을 보였으나 S. gordonii 사균에 의해서는 군집 형성이 감소되었다. 따라서 본 실험에 사용된 균주는 군집 형성 시 상호작용 인자뿐 아니라 세균 입자 그 자체 등을 통해서도 서로 영향을 주는 것으로 생각된다.

• 한국전기전자재료학회논문지
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• 제33권1호
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• pp.70-77
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• 2020

In this study, the sterilization property of E. coli was established using a plasma generator with a flexible electrode structure. The bacterial suspension was prepared based on the McFarland standard 0.50 (1.5×10⁸ CFU/mL) concentration and a specific amount was inoculated on the plate medium. After the plasma was discharged 3 cm away from the plasma generator in the range of 30s to 5 min and the results compared to the control group, the observed colonies that were formed decreased significantly as the plasma discharge time increased.

• Journal of Microbiology and Biotechnology
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• 제15권6호
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• pp.1286-1298
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• 2005

The genus Paenibacillus is a new group of bacilli separated from the genus Bacillus, and most of species have been isolated from soil. In the present study, we collected 450 spore-forming bacilli from the roots of winter crops, such as barley, wheat, onion, green onion, and Chinese cabbage, which were cultivated in the southern part of Korea. Among these 450 isolates, 104 Paenibacillus-like isolates were selected, based on their colony shape, odor, color, and endospore morphology, and 41 isolates were then finally identified as Paenibacillus spp. by 16S rDNA sequencing. Among the 41 Paenibacillus isolates, 23 were classified as P. polymyxa, a type species of the genus Paenibacillus, based on comparison of the 16S rDNA sequences with those of 32 type strains of the genus Paenibacillus from the GenBank database. Thirty-five isolates among the 41 Paenibacillus isolates exhibited antagonistic activity towards plant fungal and bacterial pathogens, whereas 24 isolates had a significant growth-enhancing effect on cucumber seedlings, when applied to the seeds. An assessment of the root-colonization capacity under gnotobiotic conditions revealed that all 41 isolates were able to colonize cucumber roots without any significant difference. Twenty-one of the Paenibacillus isolates were shown to contain the nifH gene, which is an indicator of $N_{2}$ fixation. However, the other 20 isolates, including the reference strain E681, did not incorporate the nifH gene. To investigate the diversity of the isolates, a BOX-PCR was performed, and the resulting electrophoresis patterns allowed the 41 Paenibacillus isolates to be divided into three groups (Groups A, B, and C). One group included Paenibacillus strains isolated mainly from barley or wheat, whereas the other two groups contained strains isolated from diverse plant samples. Accordingly, the present results showed that the Paenibacillus isolates collected from the rhizosphere of winter crops were diverse in their biological and genetic characteristics, and they are good candidates for further application studies.