• Preventive Nutrition and Food Science
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• 제18권4호
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• pp.273-279
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• 2013

Protease widely exists in the digestive tract of animals and humans, playing a very important role in protein digestion and absorption. In this study, a high protease-producing strain Planomicrobium sp. L-2 was isolated and identified from the digestive tract of Octopus variabilis. The strain was identified by physiological and biochemical experiments and 16S rDNA sequences analysis. A protease was obtained from the strain Planomicrobium sp. L-2 through ammonium sulfate precipitation, dialysis and enrichment, DEAE-Sephadex A50 anion-exchange chromatography, and Sephadex G-100 gel chromatography. The molecular weight and properties of the protease were characterized, including optimum temperature and pH, thermal stability, protease inhibitions and metal ions. According to our results, the protease from Planomicrobium sp. L-2 strain designated as F1-1 was obtained by three-step separation and purification from crude enzyme. The molecular weight of the protease was 61.4 kDa and its optimum temperature was $40^{\circ}C$. The protease F1-1 showed a broad pH profile for casein hydrolysis between 5.0~11.0. No residual activity was observed after incubation for 40 min at $60^{\circ}C$ and 60 min at $50^{\circ}C$. F1-1 protease was inhibited by $Mn^{2+}$, $Hg^{2+}$, $Pb^{2+}$, $Zn^{2+}$, and $Cu^{2+}$ ions, as well as PMSF, indicating that the protease F1-1 was a serine protease. Additionally, research basis provided by this study could be considered for industrial application of octopus intestinal proteases.

• Journal of Microbiology and Biotechnology
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• 제17권5호
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• pp.784-791
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• 2007

The present work aims to use a biofilter technology(aerated submerged filters) for the aerobic transformation at laboratory-scale of olive washing water(OWW) generated in the first steps of olive oil processing, as well as the genetic profiling and identification to the species level of the bacteria involved in the formation of the biofilm, by means of TGGE. Chemical parameters, such as biological oxygen demand at five days($BOD_5$) and chemical oxygen demand(COD), decreased markedly(up to 90 and 85%, respectively) by the biological treatment, and the efficiency of the process was significantly affected by aeration and inlet flow rates. The total polyphenol content of inlet OWW was only moderately reduced(around 50% decrease of the inlet content) after the biofilter treatment, under the conditions tested. Partial 16S rRNA genes were amplified using total DNA extracted from the biofilm and separated by TGGE. Sequences of isolated bands were mostly affiliated to the $\alpha-subclass$ of Proteobacteria, and often branched in the periphery of bacteria] genera commonly present in soil(Rhizobium, Reichenowia, Agrobacterium, and Sphingomonas). The data obtained by the experimentation at laboratory scale provided results that support the suitability of the submerged filter technology for the treatment of olive washing waters with the purpose of its reutilization.

• Journal of Microbiology and Biotechnology
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• 제24권3호
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• pp.313-323
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• 2014

Significant alteration in the microbial community can occur across reclamation areas suffering subsidence from mining. A reclamation site undergoing fertilization practices and an adjacent coal-excavated subsidence site (sites A and B, respectively) were examined to characterize the bacterial diversity using 454 high-throughput 16S rDNA sequencing. The dominant taxonomic groups in both the sites were Proteobacteria, Acidobacteria, Bacteroidetes, Betaproteobacteria, Actinobacteria, Gammaproteobacteria, Alphaproteobacteria, Deltaproteobacteria, Chloroflexi, and Firmicutes. However, the bacterial communities' abundance, diversity, and composition differed significantly between the sites. Site A presented higher bacterial diversity and more complex community structures than site B. The majority of sequences related to Proteobacteria, Gemmatimonadetes, Chloroflexi, Nitrospirae, Firmicutes, Betaproteobacteria, Deltaproteobacteria, and Anaerolineae were from site A; whereas those related to Actinobacteria, Planctomycetes, Bacteroidetes, Verrucomicrobia, Gammaproteobacteria, Nitriliruptoria, Alphaproteobacteria, and Phycisphaerae originated from site B. The distribution of some bacterial groups and subgroups in the two sites correlated with soil properties and vegetation due to reclamation practice. Site A exhibited enriched bacterial community, soil organic matter (SOM), and total nitrogen (TN), suggesting the presence of relatively diverse microorganisms. SOM and TN were important factors shaping the underlying microbial communities. Furthermore, the specific plant functional group (legumes) was also an important factor influencing soil microbial community composition. Thus, the effectiveness of 454 pyrosequencing in analyzing soil bacterial diversity was validated and an association between land ecological system restoration, mostly mediated by microbial communities, and an improvement in soil properties in coal-mining reclamation areas was suggested.

• Journal of Microbiology and Biotechnology
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• 제29권2호
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• pp.209-221
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• 2019

Gamma-aminobutyric acid (GABA) is a neurotransmitter that exerts several physiological functions and positive effects on human health. The aim of this study was to isolate and characterize the strains that had GABA-producing abilities from various fermented fish products. A total of 91 acid-producing strains were isolated from 41 samples of fermented fish products, and 27 strains showing GABA-producing abilities were identified by the 16S rDNA sequences. Among the strains, 31% strains tolerated at high-salt environment of 10-20% throughout the fermentation of fish sauces. The 27 isolates that produced GABA at various concentrations did so in the range of 5 to 454 mM. These GABA-producing isolates were identified as lactic acid bacteria of 14 strains, which included twelve Lactococcus lactis, one Enterococcus faecium, and one Lactococcus pentosus; eight Bacillus cereus group, which included seven B. thuringiensis and one B. cereus; and five Staphylococcus spp. Interestingly, with Vietnamese fish sauces, we mostly identified species of B. thuringiensis and Staphylococcus spp., while with Korean fermented fish products, the majority of the strains identified belonged to L. lactis. Among the strains, B. thuringiensis LH2134 produced the highest levels of GABA at 366 mM among the strains identified from Vietnamese fish sauces, whereas L. lactis LA43, a new strain isolated from Korean jeotgal (salted shrimp paste), produced the highest amount of GABA at 454 mM and the glutamate concentration in the medium was essential for GABA accumulation. Therefore, such the isolates might serve as good starters for development of more GABA-reinforced foods among fermented fish products.

• Asian-Australasian Journal of Animal Sciences
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• 제32권1호
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• pp.82-91
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• 2019

Objective: This experiment was conducted to compare the structure and composition of ruminal microorganisms in goats with high and low neutral detergent fibre (NDF) digestibility. Methods: Nineteen crossbred goats were used as experimental animals and fed the same total mixed rations during the 30-day pre-treatment and 6-day digestion trialperiods. All faeces were collected during the digestion period for measuring the NDF digestibility. Then, high and the low NDF digestibility individuals were chosen for the high NDF digestibility group (HFD) and low NDF digestibility group (LFD), respectively. Rumen contents were collected for total microbial DNA extraction. The V4 region of the bacterial 16S rRNA gene was amplified using universal primers of bacteria and sequenced using high-throughput sequencer. The sequences were mainly analysed by QIIME 1.8.0. Results: A total of 18,694 operational taxonomic units were obtained, within 81.98% belonged to bacteria, 6.64% belonged to archaea and 11.38% was unassigned microorganisms. Bacteroidetes, Firmicutes, and Proteobacteria were the predominant microbial phyla in both groups. At the genus level, the relative abundance of fifteen microorganisms were significantly higher (p<0.05) and six microorganisms were extremely significantly higher (p<0.01) in LFD than HFD. Overall, 176 core shared genera were identified in the two groups. The relative abundance of 2 phyla, 5 classes, 10 orders, 13 families and 15 genera had a negative correlation with NDF digestibility, but only the relative abundance of Pyramidobacter had a positive correlation with NDF digestibility. Conclusion: There were substantial differences in NDF digestibility among the individual goats, and the NDF digestibility had significant correlation with the relative abundance of some ruminal microorganisms.

• 한국미생물·생명공학회지
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• 제42권4호
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• pp.317-323
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• 2014

비올라세인은 항균, 항암, 항산화, 항말라리아, 항설사 활성과 같은 다양한 생리활성을 가지는 보라색소 물질로 알려져 있다. 본 연구에서는 한국의 산림토양에서 분리되었으며 보라색 색소를 생산하는 EP15224 균주를 선발하여 16S rRNA 유전자의 염기서열을 분석하였다. 그 결과 Massilia sp. BS-1과 97%의 가장 높은상동성을 보였다. 또한 16S rRNA 유전자에 근거한 계통분류학적 분석에서 EP15224는 기존 보고된 비올라세인 생산 세균들과는 별개로 구분되는 Massilia속의 새로운 종임을 확인하였다. 이 균주가 생산하는 보라색 소물질을 분리하여 LC/MS/MS로 분석한 결과, 분자량이 343.34인 비올라세인과 일치하였다. 또한 비올라세인의 생산효율을 높여주는 최적의 배지성분[glucose 2 g/l, $(NH_4)_2SO_4$ 1 g/l, $Na_2HPO_4{\cdot}7H_2O$ 2 g/l, $KH_2PO_4$ 1 g/l, $MgSO_4{\cdot}7H_2O$ 0.1 g/l, $\small{L}$-tryptophan 0.24 g/l]과 배양조건[$25^{\circ}C$에서 72시간 배양, 250 rpm, 10% 접종량]을 조사하였으며 이 조건에서 액체배양 하였을 때 리터 당 280 mg의 비올라세인이 생산되었다.

• Journal of Microbiology and Biotechnology
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• 제29권12호
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• pp.1947-1956
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• 2019

The gut microbiome influences the health and well-being of dogs. However, little is known about the impact of breed on the fecal microbiome composition in dogs. Therefore, we aimed to investigate the differences in the fecal microbiome in three breeds of dog fed and housed under the same conditions, namely eight Maltese (8.0 ± 0.1 years), eight Miniature Schnauzer (8.0 ± 0.0 years), and nine Poodle dogs (8.0 ± 0.0 years). Fresh fecal samples were collected from the dogs and used to extract metagenomic DNA. The composition of the fecal microbiome was evaluated by 16S rRNA gene amplicon sequencing on the MiSeq platform. A total of 840,501 sequences were obtained from the 25 fecal samples and classified as Firmicutes (32.3-97.3% of the total sequences), Bacteroidetes (0.1-62.6%), Actinobacteria (0.2-14.7%), Fusobacteria (0.0-5.7%), and Proteobacteria (0.0-5.1%). The relative abundance of Firmicutes was significantly lower in the Maltese dog breed than that in the other two breeds, while that of Fusobacteria was significantly higher in the Maltese than in the Miniature Schnauzer breed. At the genus level, the relative abundance of Streptococcus, Fusobacterium, Turicibacter, Succinivibrio, and Anaerobiospirillum differed significantly among the three dog breeds. These genera had no correlation with age, diet, sex, body weight, vaccination history, or parasite protection history. Within a breed, some of these genera had a correlation with at least one blood chemistry value. This study indicates that the composition of the fecal microbiome in dogs is affected by breed.

• 한국식품과학회지
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• 제40권6호
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• pp.669-673
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• 2008

청국장 내에 B. cereus을 효과적으로 저지하기 위한 생물학적제어 방법의 개발을 위하여 전통적 방법으로 제조한 백태 및 흑태 청국장으로부터 총 20종의 Bacillus 속 균주를 분리하였고, 이중에서 24시간 배양액에서 B. cereus에 대한 길항활성이 가장 높은 Bacillus sp. SC-8 균주를 선별하였다. 이 균주를 B. cereus와 혼합하여 청국장을 제조한 후 길항능을 분석한 결과 청국장 발효 중에는 B. cereus에 대한 길항효과가 있었으나, 발효 후 $4^{\circ}C$ 저장 중에는 균체수가 감소하여 억제효과가 감소하는 것으로 분석되었다. 또한 대조군으로 사용하였던 Bacillus sp. SC-15 균주에서는 배양액에서는 B. cereus에 대한 길항 활성이 낮았으나 청국장 내에서는 길항효과를 보임에 따라 청국장 발효에 관여하는 균들은 배양 환경에 따라 길항물질의 생성에 차이가 있음을 보였다.

• 한국환경생태학회지
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• 제31권5호
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• pp.444-454
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• 2017

세계 양서류 감소의 주요 요인으로 감염성 질병이 활발하게 연구되고 있으며, 야외 병원균 전파의 가능한 근원지로서 양서류 증양식장들이 언급되고 있으나, 국내에서 관련된 연구수행은 매우 미진한 상태이다. 본 연구에서는 인제, 괴산, 공주에 위치한 북방산개구리 증양식장의 내 외부에서 채집된 성체와 유생의 피부와 내부 장기들에서 확인되는 세균과 곰팡이 콜로니 수의 지역 간, 증양식장 내 외부 간 차이 여부를 파악하고, 나아가 유생으로부터 발견되는 세균의 종류를 16s rDNA 서열 비교를 통해 규명하고자 하였다. 연구결과, 성체의 경우 괴산에서 채집된 성체의 피부와 소화관으로부터 표집된 세균 콜로니 수와 피부와 간으로부터 표집된 곰팡이 콜로니 수가 인제에서 확인된 콜로니 수보다 의미 있게 많았으나 증양식장 내 외 간에는 두 지역 모두에서 어느 부위에서도 차이가 없었다. 유생의 경우 공주에서 채집된 유생의 내부로부터 표집된 곰팡이 콜로니 수가 인제에서 확인된 콜로니수보다 많은 경향을 보였다. 증양식장 내 외부의 비교 결과, 피부에서의 박테리아 수는 인제 증양식장 내부, 개체 내부에서의 박테리아 수는 공주 증양식장 외부에서 더 많은 콜로니 수가 확인되었다. 성체의 건강지수가 좋을수록 피부의 박테리아 콜로니 수와 피부와 심장의 곰팡이 콜로니 수가 적었으나, 유생에서는 관련성이 없었다. 유생으로부터 검출된 세균을 분류한 결과, 4개 문 내, 15개 속에 속하는 세균이 검출되었으나 증양식장 간 및 증양식장 내 외부 간 차이는 분명하지 않았다. 우리의 결과는 증양식장의 지역과 증양식장 내 외부 간의 서로 다른 조건들이 양서류에 있는 세균과 곰팡이의 군집크기 차이를 유발하며, 이것이 증양식 북방산개구리의 건강상태에 영향을 미칠 가능성이 있음을 보여준다. 더불어, 우리의 결과는 성공적인 양서류 증식장 운영과 증식장으로부터 질병의 가능한 야외전파를 막기 위하여, 증식장 내 효율적인 질병관리의 필요성이 높음을 시사한다.

• 생명과학회지
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• 제23권6호
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• pp.757-769
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• 2013

섬유소 분해효소(carbxymethylcellulase)를 생산하는 미생물을 해수에서 분리하여 16S rDNA 및 gyrase 유전자의 염기서열을 분석하여 동정한 결과, Bcaillus velezensis로 확인되었으며 B. velezensis A-68로 명명하였다. 이 균주가 생산하는 섬유소 분해효소의 생산 조건을 최적화하기 위하여 통계학적 방법인 response surface method (RSM)를 사용하였다. 이 균주의 생육에 최적인 왕겨, 효모 추출물 및 배지의 초기 pH는 60.2 g/l, 7.38 g/l 및 7.18이었으나, 섬유소 분해효소 생산에 최적인 왕겨, 효모 추출물 및 배지의 초기 pH는 50.0 g/l, 5.99 g/l 및 7.30이었다. 통계학적인 분석 결과, 균주의 생육 및 균주의 섬유소 분해효소 생산에 가장 큰 영향을 미치는 것은 효모 추출물이었다. 이 균주의 생육과 섬유소 분해 효소의 생산에 최적인 $K_2HPO_4$, NaCl, $MgSO_4{\cdot}7H_2O$ 및 $(NH_4)_2SO_4$의 농도는 각각 7.50, 1.00, 0.10, and 0.80 g/l이었다. 이 균주의 생육 및 섬유소 분해효소 생산에 최적인 온도는 각각 $30^{\circ}C$ 및 $35^{\circ}C$로 생육에 최적인 조건과 섬유소 분해효소 생산에 최적인 조건이 다름을 알 수 있었다. 이 균주가 생산하는 섬유소 분해효소의 생산성은 83.8 m/l이며, 이는 최적화하기 전의 생산성에 비하여 3.3배 증가한 것이다. 이 연구를 통하여 농업 부산물인 왕겨를 섬유소 분해효소 생산을 위한 기질로 개발하였으며, 해수에서 분리한 미생물을 사용함으로써 섬유소 분해효소의 생산기간을 3일로 단축할 수 있었다.