• 한국축산식품학회지
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• 제32권5호
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• pp.635-643
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• 2012

As an appraisal for the application of a new starter culture, more than 200 lactic acid bacteria strains were isolated from raw milk and healthy human feces. The strains showing excellent growth and acid production ability in 10% skim milk media were selected and identified as Lactobacillus casei based on the results of their API carbohydrate fermentation patterns, as well as 16S rDNA sequence analysis. To assess the effect of L. casei strains on irritable bowel disease (IBD), the inhibitory effect of the selected strains against the nitric oxide (NO) production of lipopolysaccharide (LPS)-stimulated RAW 264.7 cells was measured. Among the tested L. casei strains, L. casei MCL was observed to have the greatest NO inhibitory activity. Additionally, L. casei MCL was found to inhibit mRNA expression of pro-inflammatory cytokines (interleukin-$1{\beta}$, IL-6, TNF-${\alpha}$), as well as cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) involved in pathophysiologic processes such as inflammation. The mRNA expression of anti-inflammatory cytokines, including IL-10 and transforming growth factor-$1{\beta}$ (TGF-${\beta}$) of L. casei MCL, was confirmed using quantitative real-time PCR. In conclusion, L. casei MCL showed decreases in the expression of pro-inflammatory cytokines and up-regulated expression of the anti-inflammatory cytokine.

• KSBB Journal
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• 제28권6호
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• pp.349-355
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• 2013

SC092 strain, producing a polysaccharide degrading enzyme, was isolated from the seawater. This strain was identified as Microbulbifer sp. using the comparative sequence analysis against known 16S rRNA sequence. A polysaccharide degrading enzyme from this strain was used to acquire the enzymatic extracts of Sargassum fulvellum. DPPH radical scavenging and SOD activity of the enzyme extracts of S. fulvellum were about 61.9% and 82.9% at 2 mg/mL, respectively. Nitrite scavenging activities was 52.5% at 2 mg/mL on pH 1.2. In addition, ${\alpha}$-glucosidase inhibitory activity was also increased in a dose-dependent manner and was about 52.7% at 2 mg/mL. To determine the influence of enzyme extracts of S. fulvellum on alcohol metabolism, the generating activity of reduced-nicotinamide adenine dinucleotide (NADH) by alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) were measured. ADH and ALDH activities were 118.0% and 177% at 2 mg/mL, respectively. ${\alpha}$-glucosidase inhibitory activity of enzyme extracts of S. fulvellum was remarkably increased in a dose-dependent manner and was about 52.7% at 2 mg/mL. These results indicate alcoholizing and ${\alpha}$-glucosidase inhibitory activities can be enhanced by the enzymatic extracts of S. fulvellum.

• KSBB Journal
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• 제31권3호
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• pp.158-164
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• 2016

Plant growth promoting (PGP) hormones, which are produced in a small quantity by bacteria, affect in plant growth and development. PGPs play an important role on the crop productivity in agricultural field. In this study, a photosynthetic bacterial strain producing the PGP was isolated from paddy soil. Bacterial isolate was gram negative, rod-shaped and motility positive. From the 16s rRNA gene sequence analysis, the isolate was identified as Rhodobacter capsulatus PS-2. The mass cultivation of R. capsulatus PS-2 was optimized by considering of the carbon, nitrogen and inorganic salt sources. Optimal medium composition was determined as Na-succinate 4.5 g, yeast extract 5 g, $K_2HPO_4$ 1 g, $MgSO_4$ 5 g, per liter. From the result of 500 L fermentation for 2 days using the optimal medium, the viable cells were $8.7{\times}10^9cfu/mL$. R. capsulatus PS-2 strain produced the carotenoid and indole-3-acetic acid (IAA). The carotenoid extraction and quantitative analysis were performed by HCl-assisting method. Total carotenoid contents from R. capsulatus PS-2 culture broth were measured as $7.02{\pm}0.04$ and $6.93{\pm}0.05mg/L$ under photoheterotrophic and chemoheterotrophic conditions, respectively. To measure the productivity of IAA, colorimetric method was employed using Salkowski reagent at optical density 535 nm. The results showed that the highest content of IAA was $197.44{\pm}5.92mg/L$ in the optimal medium supplemented with 0.3% tryptophan.

• 미생물학회지
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• 제46권4호
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• pp.359-365
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• 2010

조릿대 근권토양으로부터 분리한 방선균 50균주를 대상으로 고추 세균성 점무늬병원균(Xanthomonas axonopodis pv. vesicatoria)의 항균활성 12균주를 선발하였다. 이들 항균활성 12균주의 계통학적 위치를 검토한 결과, 모두 Streptomyces 속의 Cluster II에 속하는 특징을 나타내었다. JR-24 균주는 최소저해 농도(MIC) 10 ${\mu}l$/disc를 나타내었으며, 배양액 5 ${\mu}l$/ml를 처리 하여 12시간 배양한 결과 Xanthomonas axonopodis pv. vesicatoria에 강한 생육저해효과를 나타내어 최우수 균주로 선발되었다. 항균활성 균주 JR-24의 16S rRNA 유전자 염기서열을 검토한 결과, Streptomyces galbus $DSM40089^T$ (X79852)와 98.1%, Streptomyces longwoodensis $LMG20096^T$ (AJ781356)와 98% 그리고 Streptomyces capoamus $JCM4734^T$ (AB045877)와 97.8%의 상동성을 나타내었다. API 20NE와 API 50CHE를 이용하여 JR-24 균주의 생리 생화학적 특성을 확인한 결과, L-arabinose, D-fructose, D-glucose, D-galactose을 이용하며 gelatin, protein, starch에 대하여 분해능이 있는 것으로 확인되었다. 주요지방산으로는 iso-$C_{14:0}$ (25.93%), iso-$C_{15:0}$ (10.13%), anteiso-$C_{15:0}$ (19.29%) 그리고 iso-$C_{16:0}$ (20.35%) 등을 함유하였으며, 퀴논종은 MK-9 ($H_4$) 4.37%, MK-9 ($H_6$) 51.22% 그리고 MK-9 ($H_8$) 49.47%로 동정되었다. Streptomyces sp. JR-24 균주의 계통학적 특성을 근연종인 Streptomyces galbus $DSM40089^T$와 비교한 결과, 다수의 표현형적 및 계통학적 차이를 나타내었다. 본 연구에서 분리된 Streptomyces sp. JR-24는 친환경 미생물제제 개발을 위한 유전자원 확보에 있어서 매우 큰의의가 있을 것으로 사료 된다.

• 한국미생물·생명공학회지
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• 제30권2호
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• pp.129-134
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• 2002

토종닭 소장으로부터 가축 소화기 병원성 유해세균의 분리를 위하여 무작위 선별법과 중층-도말법을 사용하여 총130주의 유산균을 1차 분리하였다. 1차 분리한 130주를 paper disc법을 사용하여 최종적으로 살모넬라 균, 포도상구균, 대장균에 대하여 저해능이 우수한 7주를 분리하였다. 분리 균주의 동정을 위하여 1차로 API CHL kit를 사용하였고, 동정의 정확성을 높이기 위하여 2차로 16S rRNA sequencing 방법을 사용하였다. 그 결과 BD14 균주는 Pediococcus pentosaceus로 동정되었으며 나머지 6주는 Lactobacillus sp.로 동정되어 모두 안전성 있는 유산균임을 확인하였다. 여러 병원균에 가장 항균력이 큰 유산균은 L. pentosus K34이었으며, 이 유산균은 염산과 담즙산에 대한 내성에서도 가장 우수한 균주로 나타났다. 10종의 항생제에 대한 감수성을 조사한 결과 ciprofloxacin에 대하여 모든 균주가 내성을 보였고, BL 균주를 제외하고 모든 균주가 colistin, streptomycin에 대하여 내성을 보였다. 또한 BD14, BD16, K34 균주가 gentamicin에 대한 내성을 보였다.

• Journal of Dairy Science and Biotechnology
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• 제37권2호
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• pp.115-128
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• 2019

본 연구는 전통 김치로부터 유단백질 분해능과 lactose 분해능을 가지는 유산균을 선발하고, 프로바이오틱 활성을 측정하여 발효유용 스타터로서의 이용가능성을 조사하였다. BCP agar에서 젖산생성력이 우수한 32 colony를 선발한 후 내산성 및 내담즙성 모두에서 90% 이상으로 내성이 우수한 2 colony(KC23, KF26)를 2차로 선발하였다. 이들을 대상으로 API 50CHL 탄수화물 이용성 테스트 및 16S rRNA 염기서열을 분석한 결과, L. plantarum KC23과 L. paracasei KF26으로 동정되었다. 이들 중 lactose와 raffinose를 포함하여 당분해능을 가진 L. plantarum KC23을 최종 선발하고 프로바이오틱 활성을 조사하였다. 우유단백질 분해능을 10% 환원탈지유 배양 중의 유리 tyrosine 함량으로 측정한 결과, 배양 8시간 후에는 $24.1{\mu}g/mL$에서 배양 16시간 후에는 $43.9{\mu}g/mL$로 급격하게 증가되었으며, 또한 clear zone형성 크기를 비교한 결과 12 mm로 상업균주인 L. acidophilus CSLA의 9 mm보다 우수한 특성을 보였다. 온도별 생장특성을 확인한 결과는 $45^{\circ}C$에서 보다 $35^{\circ}C$에서 잘 증식하는 중온균의 특성을 나타내었고, $37^{\circ}C$에서 12시간 동안 배양한 결과 배양 6-10시간 사이에 대수증식기를 보였으며, 배양 12시간 후 생균수는 $8.9{\times}10^8CFU/mL$와 pH 4.25 수준을 나타내었다. 항균활성을 측정한 결과는 5개 병원성균에 대하여 8-13 mm의 clear zone을 형성하여 우수한 저해특성을 보였으며, 그중 Salmonella typhimurium과 Bacillus cereus에 대한 항균활성이 가장 우수하였다. 장내부착능을 측정한 결과는 비교균주인 LGG에 비하여 2.23배의 우수한 결과를 보였으며, 10% 환원탈지유를 이용한 $37^{\circ}C$ 배양에서 젖산생성능을 확인한 결과는 대조군인 L. acidophilus CSLA에 비하여 다소 낮은 경향을 보였지만, 적정산도가 0.74% 수준으로서 저산성 발효유 제조를 위한 스타터로 활용 가능할 것으로 판단되었다.

• 대한수의학회지
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• 제38권3호
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• pp.559-564
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• 1998

The polymerase chain reaction(PCR) assay was used for rapid diagnosis from blood and organ samples experimentally infected with Listeria monocytogenes. This method used a pair of primers based on a unique region in the 16S rRNA sequence of L monocytogenes. Procedure A was based on dilution of the blood sample followed by lysis of bacterial cell and direct analysis of the lysate with PCR. In artificially infected blood samples with L monocytogenes, it was possible to detect fewer than 40 cells per ml of blood. However, L monocytogenes was detected low rates on infected organs by the direct PCR. In procedure B, enrichment cultivation was used to increase numbers of bacteria before lysis and PCR. L monocytogenes was detected from 23 samples of 24 liver and spleen, respectively, and 18 samples of 24 blood were found to be positive by PCR on a subset of 72 organ samples, whereas L monocytogenes were detected on 63 organ samples in classical culture technique. It was required to analyze including enrichment steps were 6h and 18h on the procedure A and B, respectively.

• 한국수산과학회지
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• 제49권6호
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• pp.792-799
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• 2016

We isolated seven tryptamine-producing bacteria from commercial salted and fermented sand lance (Ammodytes personatus) sauces using an L-tryptophan decarboxylating medium. These tryptamine-producing bacteria, identified using an API kit and 16S rRNA analysis, included Lysinibacillus xylanilyticus (one strain), Lysinibacillus fusiformis (four strains), and Staphylococcus epidermidis (two strains). Lysinibacillus spp. produced the highest levels of tryptamine in culture broth containing 0.5% L-tryptophan, compared with 1.0% and 2.0% preparations. After 72 h of incubation, Staphylococcus epidermidis produced the highest levels of tryptamine ($60.50{\mu}g/mL$ and $664.86{\mu}g/mL$) in culture broth containing 2.0% L-tryptophan. While Lysinibacillus spp. comprised the dominant tryptamine-producing bacteria in sand lance sauces, Staphylococcus epidermidis also showed high tryptamine-producing activity. This is the first report on the isolation and identification of tryptamine-producing bacteria in sand lance sauces.

• Journal of Microbiology and Biotechnology
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• 제34권6호
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• pp.1239-1248
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• 2024

Peatlands are marginal agricultural lands due to highly acidic soil conditions and poor drainage systems. Drought stress is a big problem in peatlands as it can affect plants through poor root development, so technological innovations are needed to increase the productivity and sustainability of upland rice on peatlands. Rhizobacteria can overcome the effects of drought stress by altering root morphology, regulating stress-responsive genes, and producing exopolysaccharides and indole acetic acid (IAA). This study aimed to determine the ability of rhizobacteria in upland rice to produce exopolysaccharides and IAA, identify potential isolates using molecular markers, and prove the effect of rhizobacteria on viability and vigor index in upland rice. Rhizobacterial isolates were grown on yeast extract mannitol broth (YEMB) medium for exopolysaccharides production testing and Nutrient Broth (NB)+L-tryptophan medium for IAA production testing. The selected isolates identify using sequence 16S rRNA. The variables observed in testing the effect of rhizobacteria were germination ability, vigour index, and growth uniformity. EPS-1 isolate is the best production of exopolysaccharides (41.6 mg/ml) and IAA (60.83 ppm). The isolate EPS-1 was identified as Klebsiella variicola using 16S rRNA sequencing and phylogenetic analysis. The isolate EPS-1 can increase the viability and vigor of upland rice seeds. K. variicola is more adaptive and has several functional properties that can be developed as a potential bioagent or biofertilizer to improve soil nutrition, moisture and enhance plant growth. The use of rhizobacteria can reduce dependence on the use of synthetic materials with sustainable agriculture.

• 미생물학회지
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• 제44권4호
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• pp.311-316
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• 2008

BTEX 분해능을 가진 BJ10세균을 이용하여 호기조건에서 toluene 첨가 시 tetrachloroethylene (PCE) 분해에 관한 연구를 수행하였다. BJ10은 형태학적 특징, 생리 생화학적 특징, 16S rRNA 염기서열 분석 및 지방산 분석 결과에 따라 Pseudomonas putida로 동정되었다. BJ10의 PCE 저농도 5 mg/L에서 PCE 분해 실험 결과(toluene 첨가 기질 농도 50mg/L, 균초기 접종농도 1.0g/L, 온도 $30^{\circ}C$, pH7 그리고 DO $3.0{\sim}4.2\;mg/L$), 10일간 52.8%의 분해 효율을 보였으며, PCE 분해 속도는 5.9 nmol/hr로 나타났다. 또한 BJ10의 PCE 고농도 100 mg/L에서 PCE 분해 실험 결과 (toluene 첨가 기질 농도 50 mg/L, 균 초기 접종 농도 1.0 g/L, 온도 $30^{\circ}C$, pH 7 그리고 DO $3.0{\sim}4.2\;mg/L$), 10일간 20.3%의 분해 효율을 보였으며, PCE 분해 속도는 46.0 nmol/hr로 나타났다. Toluene 첨가 농도에 따른 PCE 분해 효율 증감 효과를 알아보기 위하여, 동일한 배양 조건하에 10 mg/L의 PCE에 toluene ($5{\sim}200\;mg/L$)을 첨가하여 분해 실험을 실시한 결과, toluene 200 mg/L 첨가시 10일간 57.0%의 PCE가 분해되어 가장 높은 제거 효율을 보였다. 또한 PCE 5.5 mg/L(총 7.6 mg/L)를 추가적으로 주입하여 동일조건하에서 PCE 분해를 확인하였으며 결과적으로 8일 동안 63.0%의 PCE가 분해되었다. 이 때의 PCE 분해 속도는 13.5 nmol/hr로 초기의 분해속도(8.1 nmol/hr)보다 증가되었다.