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

• 한국미생물·생명공학회지
• /
• 제37권4호
• /
• pp.340-349
• /
• 2009

메주로부터 항진균 및 항세균 활성을 나타내는 균주를 분리하고 동정하여 B. polyfermenticus CJ9로 명명하였다. B. polyfermenticus CJ9의 생육에 따른 항균 활성을 측정한 결과 항세균 활성은 배양 12시간에 최대 활성을 나타내며 72시간까지 90% 이상 활성을 유지하다 120시간에 활성을 완전히 상실하였다. 항진균 활성은 배양 24시간 이후부터 최대 활성을 나타내었고, 사멸기 이후 활성이 다소 감소되었으나 배양 120시간까지 활성이 유지되었다. B. polyfermenticus CJ9은 식품과 인체에 유해한 곰팡이, 효모, 그람 양성 및 음성 세균에 대한 항진균 활성과 항세균 활성을 동시에 나타내었다. B. polyfermenticus CJ9의 항세균 활성은 $37^{\circ}C$ 에서 24시간 열처리 후에 활성을 상실하였으며, pH 5.0~9.0 구간에서는 안정한 활성을 나타내었으나 pH 3.0~4.0 구간에서 활성이 감소하였다. 항진균 물질은 $121^{\circ}C$에서 15분간 열처리시 활성이 감소되었으나 역가가 완전히 소실되지 않았으며, pH 3.0~9.0 구간에서 안정한 활성을 나타내었다. 항세균 물질과 항진균 물질은 proteinase K, protease, trypsin, $\alpha$-chymotrypsin 등의 단백분해효소 처리로 역가를 상실하거나 일부 감소되어 단백질성 물질임을 추정하였다. B. polyfermenticus CJ9의 항세균 물질과 항진균 물질을 $C_{18}$ Sep-Pak column에 흡착된 분획으로부터 역가를 확인하여 소수성 물질임을 알 수 있었으며, Tricine-SDS-PAGE 및 direct detection 실험을 통하여 분자량을 확인한 결과 항진균 물질은 약 1.4 kDa의 물질임을 확인하였다. 그러나 항세균 활성 물질은 열 불안정성 때문에 동 실험법상에서 그 분자량을 확인할 수 없었다. B. polyfermenticus CJ9이 생산하는 항균 물질은 항세균 및 항진균 활성을 동시에 가지는 단백질성 물질로서 천연 식품보존제 및 정장제재로 활용이 기대되며, 이를 위하여 항세균 물질과 항진균 물질의 정제 및 구조분석 등의 연구가 필요하다.

• Journal of Microbiology and Biotechnology
• /
• 제25권7호
• /
• pp.1136-1145
• /
• 2015

The diverse microbial communities that colonize distinct segments of the gastrointestinal tract are intimately related to aspects of physiology and the pathology of human health. However, most recent studies have focused on the rectal or fecal microbiota, and the microbial signature of the duodenum is poorly studied. In this study, we compared the microbiota in duodenal and rectal samples to illustrate the characteristic microbial signatures of the duodenum in healthy adults. Nine healthy volunteers donated biopsies and luminal contents from the duodenum and rectum. To determine the composition and diversity of the microbiota, 454-pyrosequencing of bacterial 16S rRNA was performed and multiple bioinformatics analyses were applied. The α-diversity and phylogenetic diversity of the microbiota in the duodenal samples were higher than those of the rectal samples. There was higher biodiversity among the microbiota isolated from rectal biopsies than feces. Proteobacteria were more highly represented in the duodenum than in the rectum, both in the biopsies and in the luminal contents from the healthy volunteers (38.7% versus 12.5%, 33.2% versus 5.0%, respectively). Acinetobacter and Prevotella were dominant in the duodenum, whereas Bacteroides and Prevotella were dominant in the rectum. Additionally, the percentage of OTUs shared in biopsy groups was far higher than in the luminal group (43.0% versus 26.8%) and a greater number of genera was shared among the biopsies than the luminal contents. Duodenal samples demonstrated greater biological diversity and possessed a unique microbial signature compared with the rectum. The mucosa-associated microbiota was more relatively conserved than luminal samples.

• Journal of Microbiology and Biotechnology
• /
• 제28권11호
• /
• pp.1834-1845
• /
• 2018

The lactobacilli associated with a fermented goat milk product from Tajikistan were isolated to characterize their technological properties and antibiotic resistances in order to assess their suitability for development as starter cultures. In this study, twenty three strains were identified by 16S rRNA sequencing as typical dairy-associated lactic acid bacterial strains, i.e. L. plantarum, L. pentosus, L. delbrueckii, L. helveticus and L. paracasei. These strains were generally susceptible to most antibiotics tested in this study and this allowed a selection of strains as safe starters. The draft genomes of four representative strains were sequenced and the number of contigs of the four assembled genomes ranged from 51 to 245 and the genome sizes ranged from 1.75 to 3.24 Mbp. These representative strains showed differences in their growth behavior and pH-reducing abilities in in vitro studies. The co-inoculation of these Lactobacillus spp. strains together with a yeast Kluyveromyces marxianus MBT-5698, or together with the yeast and an additional Streptococcus thermophilus MBT-2, led to a pH reduction to 3.4 after 48 h. Only in the case of fermentation inoculated with the co-culture, the viscosity of the milk increased noticeably. In contrast, fermentations with single strains did not lead to gelation of the milk or to a decrease in the pH after 24h. The results of this study provide a comprehensive understanding of the predominant lactobacilli related to Tajikistani fermented milk products.

• Tuberculosis and Respiratory Diseases
• /
• 제79권3호
• /
• pp.165-178
• /
• 2016

Background: Although recent metagenomic approaches have characterized the distinguished microbial compositions in airways of asthmatics, these results did not reach a consensus due to the small sample size, non-standardization of specimens and medication status. We conducted a metagenomics approach by using terminal restriction fragment length polymorphism (T-RFLP) analysis of the induced whole sputum representing both the cellular and fluid phases in a relative large number of steroid $na{\ddot{i}}ve$ asthmatics. Methods: Induced whole sputum samples obtained from 36 healthy subjects and 89 steroid-$na{\ddot{i}}ve$ asthma patients were analyzed through T-RFLP analysis. Results: In contrast to previous reports about microbiota in the asthmatic airways, the diversity of microbial composition was not significantly different between the controls and asthma patients (p=0.937). In an analysis of similarities, the global R-value showed a statistically significant difference but a very low separation (0.148, p=0.002). The dissimilarity in the bacterial communities between groups was 28.74%, and operational taxonomic units (OTUs) contributing to this difference were as follows: OTU 789 (Lachnospiraceae), 517 (Comamonadaceae, Acetobacteraceae, and Chloroplast), 633 (Prevotella), 645 (Actinobacteria and Propionibacterium acnes), 607 (Lactobacillus buchneri, Lactobacillus otakiensis, Lactobacillus sunkii, and Rhodobacteraceae), and 661 (Acinetobacter, Pseudomonas, and Leptotrichiaceae), and they were significantly more prevalent in the sputum of asthma patients than in the sputum of the controls. Conclusion: Before starting anti-asthmatic treatment, the microbiota in the whole sputum of patients with asthma showed a marginal difference from the microbiota in the whole sputum of the controls.

• 환경생물
• /
• 제24권1호
• /
• pp.38-45
• /
• 2006

경상북도내의 금속광산, 공장 및 공업지역의 토양의 오염도를 조사하고 중금속 오염토양 중에 분포하는 미생물 flora의 정량적 평가를 위하여 청정지역인 독도토양과 비교한 결과, 일반세균의 경우 $10\sim100$배 낮은 분포율을 나타내었으며, 6가크롬 오염토양 중 곰팡이는 거의 검출되지 많았다. 방선균은 수은 오염토양의 경우 $6.7X10^5\sim7.5X10^7\;cfu\;g^{-1}$, 6가크롬 오염토양 내 방선균 수는 $4.8X10^4\sim5.0X10^5\;cfu\;g^{-1}$이 측정되어 대조구 토양 내 방선균 분포와 비슷한 높은 분포율을 나타내었다. 수은 오염토양 시료를 $HgCl_2$ 50ppm과 100ppm을 각각 첨가한 배지에 접종하여 방선균수를 측정한 결과 대조구 토양에 비해 10배 이상의 높은 수를 확인하였다. 수은 및 6가크롬의 오염토양으로부터 분리된 방선균 150 균주에 대해 항균력을 검토한 결과 31균주가 양성반응을 나타내었다. 이들 방선균 중 강한 항균활성을 나타낼 10균주를 선발하여 계통학적 특성을 검토한 결과 Streptomyces 속, Saccharopolyspora 속, 그리고 Nocardioides 속에 속하는 3개의 계통군으로 분류되었다. 이들 분리균주중에는 기지 미생물종과 97% 이하의 낮은 상동성을 나타내는 신규미생물도 다수 포함되어 있었다. 이상의 결과로부터, 본 연구에서 조사된 수은 및 6가크롬 오염토양내 중금속 내성 및 항균활성을 갖는 방선균이 높게 분포해 있음이 확인되어, 난분해성 화합물을 포함한 다양한 구조의 유해 독성물질의 정균작용으로 인한 중금속 오염토양 내 환경의 복원이 효율적으로 이루어 질 수 있을 것으로 기대되었다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제30권7호
• /
• pp.950-956
• /
• 2017

Objective: Effects of newly isolated Lactobacillus plantarum on the fermentation and chemical composition of fresh rice straw silage was evaluated in this study. Methods: Lactic acid bacteria (LAB) from good crop silage were screened by growing them in MRS broth and a minimal medium with low carbohydrate content. Selected LAB (LAB 1821) were Gram-positive, rods, catalase negative, and were identified to be Lactobacillus plantarum based on their biochemical characteristics and a 16S rRNA analysis. Fresh rice straw was ensiled with two isolated LAB (1821 and 1841), two commercial inoculants (HM/F and P1132) and no additive as a control. Results: After 2 months of storage at ambient temperature, rice straw silages treated with additives were well-preserved, the pH values and butyric and acetic acid contents were lower, and the lactic acid content and lactic/acetic acid ratio were higher than those in the control (p<0.05). Acidity (pH) was lowest, and lactic acid highest, in 1821-treated silage (p<0.05). The $NH_3-N$ content decreased significantly in inoculant-treated silage (p<0.05) and the $NH_3-N$ content in 1821-treated silage was lowest among the treatments. The dry matter (DM) content of the control silage was lower than that of fresh rice straw (p<0.05), while that of the 1841- and p1174-inoculant-treated silages was significantly higher than that of HM/F-treated silage. Microbial additives did not have any significant (p>0.05) effect on acid detergent fiber or neutral detergent fiber contents. Crude protein (CP) content and in vitro DM digestibility (IVDMD) increased after inoculation of LAB 1821 (p<0.05). Conclusion: LAB 1821 increased the CP, IVDMD, lactic acid content and ratio of lactic acid to acetic acid in rice straw silage and decreased the pH, acetic acid, $NH_3-N$, and butyric acid contents. Therefore, adding LAB 1821 improved the fermentation quality and feed value of rice straw silage.

• 한국식품저장유통학회지
• /
• 제19권5호
• /
• pp.757-766
• /
• 2012

향미가 우수한 100년 묵은 재래 간장에서 부터 강력한 항진균 활성(antifungal)균주를 분리 동정하여 Bacillus velelzensis SSH100-10으로 명명하였다. B. velezensis SSH100-10은 식품 위해 및 식품 변패곰팡이에 대한 항곰팡이 활성과 장류에 이취를 주는 산막효모 등에 대한 항효모 활성이 동시에 있으며, 강력한 단백분해활성을 나타내었다. NaCl 내염성도 우수하여 12% NaCl 농도하에서도 생육 48시간에 $A_{600}$에서 3.51의 생육도를 나타내었다. 또한 최근 Bacillus subtilis group 중 일부 균주에서 설사형 독소인 enterotixon을 나타내는 균주들에 대한 보고가 증가함에 따라, 안전성검증의 일환으로 enterotoxin 생성 여부를 조사하였을 때, 본 분리 균주는 enterotoxin 검지반응에서 음성을 나타내었다. B. velezensis SSH100-10이 생산하는 항진균 활성물질을 SPE, preparative HPLC, reverse phase-HPLC로 정제 후, MALDI-TOF-MS와 아미노산 조성 분석을 통하여 그 항진균 원인 물질이 $C_{14}$ iturin A와 $C_{15}$ iturin A 임을 구명하였다. 또한 B. velezensis SSH100-10의 배양상징액과 분리 정제된 항진균 물질 $C_{14}$ iturin A와 $C_{15}$ iturin A와 대조구로 시판되는 $C_{14{\sim}15}$ iturin A의 pH, 온도, 효소 안정성 실험을 통하여 B. velezensis SSH100-10은 pH, 열, 효소처리에 매우 안정한 iturin A 이외에도 pH에 불안정한 또 다른 구명되지 않은 항진균 물질을 생산함을 보고하였다. 본 연구에서 보고된 강력한 항진균 활성을 지니는 B. velezensis SSH100-10은 맛있는 발효과정의 종균으로서의 작용과 더불어 콩발효식품에서 유해요소가 될 수 있는 바람직하지 못한 미생물을 제어함으로서 콩발효식품의 안전과 위생수준을 개선할 수 있는 우수한 종균으로 활용될 수 있을 것이다.

• Journal of Microbiology and Biotechnology
• /
• 제33권10호
• /
• pp.1292-1298
• /
• 2023

PAMB 00755^T, a bacterial strain, was isolated from Korean fir leaves. The strain exhibits yellow colonies and consists of Gram-negative, non-motile, short rods or ovoid-shaped cells. It displays optimal growth conditions at 20℃, 0% NaCl, and pH 6.0. Results of 16S rRNA gene-based phylogenetic analyses showed that strain PAMB 00755^T was most closely related to Sphingomonas chungangi MAH-6^T (97.7%) and Sphingomonas polyaromaticivorans B2-7^T (97.4%), and ≤96.5% sequence similarity to other members of the genus Sphingomonas. The values of average nucleotide identity (79.9-81.3%), average amino acid identity (73.3-75.9%), and digital DNA-DNA hybridization (73.3-75.9%) were significantly lower than the threshold values for species boundaries; these overall genome-related indexes (OGRI) analyses indicated that the strain represents a novel species. Genomic analysis revealed that the strain has a 4.4-Mbp genome encoding 4,083 functional genes, while the DNA G+C content of the whole genome is 66.1%. The genome of strain PAMB 00755^T showed a putative carotenoid biosynthetic cluster responsible for its antioxidant activity. The respiratory quinone was identified as ubiquinone 10 (Q-10), while the major fatty acids in the profile were identified as C_18:1ω7c and/or C_18:1ω6c (summed feature 8). The major polar lipids of strain PAMB 00755^T were diphosphatidylglycerol, phosphatidylethanolamine, sphingoglycolipid, and phosphatidylcholine. Based on a comprehensive analysis of genomic, phenotypic, and chemotaxonomic characteristics, we proposed the name Sphingomonas abietis sp. nov. for this novel species, with PAMB 00755^T as the type strain (= KCTC 92781^T = GDMCC 1.3779^T).

• 미생물학회지
• /
• 제42권1호
• /
• pp.40-46
• /
• 2006

우유에 풍부하게 존재하는 유당은 galactose와 포도당의 $\beta(1\rightarrow4)$ glycosidic 결합으로 구성되어 있고, 인간에서 이를 가수분해하는 효소는 lactase, 세균에서는 $\beta-galactosidase$로 알려져 있다. Lactase의 활성이 낮은 사람이 우유를 섭취했을 경우 일시적인 설사를 일으키고 때로는 만성적인 대감의 염증으로 인한 만성설사의 원인이 되기도 한다. 겨울철에 젖소를 사육하는 축사 주변에서 저온에서 생육하는 세균 AS-20을 분리하여 $\beta-galactosidase$ 활성을 갖는 균주를 선별하고 온도별로 분리균의 성장을 조사하였다. 그 결과 대장균이 자라지 못하는 $10^{\circ}C$에서도 분리된 AS-20은 생육이 가능하였고 생육 최적온도는 $30^{\circ}C$이였으며 이 온도에서 세대시간은 60여분 이었다. AS-20의 생화학적 특성을 bioMerieux Vitek Gram negative identification card (GNI+)로 조사한 결과 포도당을 발효, 산화시켰으며 유당, maltose, mannitol, xylose, L-arabinose 등을 이용하여 97% Hafnia alvei, 2% Escherichia coli로 동정되었다. Polymerase chain reaction으로 16S rRNA유전자를 증폭하여 1,426 bp의 염기서열을 결정하여 기존에 보고된 유전자들과의 유사도를 조사한 결과 분리된 균주 AS-20은 Hafnia alvei와 99%의 염기서열상 동성을 보였다. 이러한 결과는 BioMerieux Vitek Gram negative identification card 키트로 동정한 결과와 일치하였다. AS-20을 $10^{\circ}C,\;20^{\circ}C,\;30^{\circ}C$에서 배양하면서 $\beta-galactosidase$ 활성을 조사한 결과 저온인 $10^{\circ}C$와 $20^{\circ}C$에서 배양하였을 때에 배양최적 온도인 $30^{\circ}C$에서 배양했을 때 보다 1.5 배 정도 높은 효소활성을 보여주었으며, $30^{\circ}C$에서 배양된 대장균 보다 6배 이상의 효소활성을 보여 주어 저온조건에서 분리균의 효소생산이 비교적 높은 것으로 판단되었다.