• International Journal of Industrial Entomology and Biomaterials
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• 제4권2호
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• pp.127-131
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• 2002

The qualitative and quantitative changes of bacterial flora associated with the Pure Mysore (Multivoltine) and NB$_4$D$_2$ (Bivoltine) silkworm (Bombyx modi L.) midgut during third, fourth and fifth instars were studied. Larvae reared on mulberry leaves were dissected and their midgut bacterial populations were enumerated through serial dilution technique and after 72 hrs of incubation period at 28 $\pm$ 1$^{\circ}C$, the bacterial population was estimated. The results showed a highest mean value of 15$\times$10/ sup 6/ sup 6/ CFU/g and 28$\times$10/ sup 6/ CFU/g in Pure Mysore and NB$_4$D$_2$races, respectively, in midgut tissue of fifth instar larvae. The natural epiphytic microflora of mulberry leaves fed during the respective instars was also studied and found maximum 14$\times$10$^3$ CFU/g in leaves fed in third instars, followed by 5.3$\times$10$^3$ CFU/g and 2.1$\times$10$^3$ CFU/g in leaves fed during fourth and fifth instars, respectively. The bacterial flora colonized in midgut was found to be elaborating amylase, caseinase, gelatinase, lipase and urease enzymes. The highest percentages of isolates were amylase producers followed by protein and lipid splitters in Pure Mysore, whereas in NB$_4$D$_2$ protein splitter were dominated followed by lipase and amylase producers in NB$_4$D$_2$. The results indicate that the natural microflora may play a vital role in the digestion of ingested food materials in silkworms.

• 한국수산과학회지
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• 제29권1호
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• pp.9-16
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• 1996

1992년 8월 6일부터 8월 14일까지에 걸쳐 조사한 동중국해 및 여수연안의 세균 flora, Vibrio spp., 대장균군에 대한 양적인 수평분포를 조사하여 미생물 생태계 해석을 위한 자료를 얻고자 실험한 결과를 요약하면 다음과 같다. 1. 동중국해의 염분농도는 $24.64\~33.78\%_{\circ}$였고, 외양으로 갈수록 낮아졌다. 2. 수온은 $22.53\~29.18^{\circ}C$였고, 연안에 비해 외양으로 갈수록 높게 나타났다. 3. 여수 연안 해수중의 일반세균수는 $1.0\times10^2\~3.0\times10^4/ml$, Vibrio spp.는 $0.2\times10\~9.0\times10^3/ml$, 대장균군은 $0.3\times10\~3.0\times10^3/ml$로서 연안에서 멀어질수록 균량은 감소하였다. 4. 동중국해 해수중의 일반세균수는 $0.4\times10\~2.0\times10^3/ml$, vibrio spp.는 $0.8\times10\~3.0\times10/ml$, 대장균군은 $0.9\times10\~l.3\times10/ml$였고, 외양으로 갈수록 일반세균은 적게 나타났으며, Vibrio spp.와 대장균군은 나타나지 않았다. 5. 동중국해에서 Vibrio spp.와 대장균군의 출현한 곳은 중국연안에 가까운 해역이였다.

• 한국수산과학회지
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• 제17권5호
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• pp.398-404
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• 1984

단백질 폐수처리시의 세균학적 변동을 조사하기위해 연제품 가공공장 폐수중 기계적인 세정수를 시료로 하여 회분 및 연속배양을 행하여 얻은 결과는 다음과 같다. 1. 활성스럿지에 의한 연제품 폐수처리에서의 BOD및 COD 제거율은 모두 $90\%$이상으로 양호한 결과를 얻었다. 2. 단백질폐수의 질산화과정에서 $NH_4-N$와 $NO_2-N$은 48시간까지 계속 증가하는 경향을 나타냈으나 $NO_3-N$는 별 변동이 없었다. 3. 원료폐수중의 세균을 회분배양에서 10 일간 순양해서 얻은 활성스럿지 가운데는 질산화능이 우수한 균은 나타나지 않았다. 4. 분리균 120균주 가운데서 Enterobacteriaceae가 $25\%$, Pseduomonas가 $23\%$로 이 이속이 우점종이었고 암모니아가 다량생산되는 폭기후기에는 Pseudomonas는 감소하는 경 향을 보였고 Enterobacteriaceae와 Aeromonas가 출현율이 높았다. 5. 염분요구성은 120 세주중 $50\%$가 $0\%,\;3\%$ NaCl, $75\%$ ASW의 식염농도하에서 생육가능한 균이었음으로 농후한 단백질폐수의 희석수로 해수를 이용할 수 있다는 것을 알 수 있었다.

• Journal of Oral Medicine and Pain
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• 제21권1호
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• pp.123-131
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• 1996

Bacteremia occurs in a wide variety of clinical procedures in oral cavity. Reduction of the number of causative microorganisms of infective endocarditis in oral cavity by local administration of antimicrobial agents decreases the magnitude of bacteremia and possibility of infective endocarditis. The effects of chlorhexidine on Streptococcus sanguis, Streptococcus mitis, Streptococcus mutans, Streptococcus oralis, Streptococcus gordonii, Staphylococcus aureus, and Staphylococcus epidermis were investigated by measurement of turbidity. The effects of 0.1% chlorhexidine gargling for 7 days on oral bacterial flora, total streptococci, S. mutans, S. aureus, and S. epidermis in whole saliv a of 7 healthy human subjects, were investigated by measurement of Colony Forming Units (CFU). The obtained results were as follows : 1. Chlorhexidine showed significant antimicrobial effects on Streptococcus snaguis, Streptococcus mitis, Streptococcus mutans, Streptococcus oralis, Streptococcus gordonii, Staphylococcus aureus, and Staphylococcus epidermis. However, the effects on S. sanguis and S. gordonii were not apparent compared with other microorganisms. 2. Oral gargling of 0.1% chlorhexidine decreased the CFU values of normal oral bacterial flora, total streptococci, S. mutans, S. aureus, and S. epidermis in whole saliva. The antimicrobial effects were significant after 4 days of chlorhexidine gargling. 3. Local antimicrobial administration in addition to systemic antibiotic prophylaxis can be highly recommended as an effective adjunct regimen for prevention of infective endocarditis.

• IMMUNE NETWORK
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• 제14권1호
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• pp.7-13
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• 2014

Molecular mimicry is an attractive mechanism for triggering autoimmunity. In this review, we explore the potential role of evolutionary conserved bacterial proteins in the production of autoantibodies with focus on granulomatosis with polyangiitis (GPA) and rheumatoid arthritis (RA). Seven autoantigens characterized in GPA and RA were BLASTed against a bacterial protein database. Of the seven autoantigens, proteinase 3, type II collagen, binding immunoglobulin protein, glucose-6-phosphate isomerase, ${\alpha}$-enolase, and heterogeneous nuclear ribonuclear protein have well-conserved bacterial orthologs. Importantly, those bacterial orthologs are also found in human-associated bacteria. The wide distribution of the highly conserved stress proteins or enzymes among the members of the normal flora and common infectious microorganisms raises a new question on how cross-reactive autoantibodies are not produced during the immune response to these bacteria in most healthy people. Understanding the mechanisms that deselect auto-reactive B cell clones during the germinal center reaction to homologous foreign antigens may provide a novel strategy to treat autoimmune diseases.

• 한국임상수의학회지
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• 제28권5호
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• pp.516-518
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• 2011

한국 황새복원센터에서 사육중인 황새의 정상 장내 세균총을 검사하기 위한 조사를 실시하였다. 44마리의 건강한 황새의 총배설강으로부터 44개의 분변시료를 채취하여 호기 및 혐기조건에서 배양하였다. 배양된 미생물의 16Sribosomal RNA 및 heat shock protein 60 유전자의 염기서열을 조사하였다. 호기조건 하에서는 Enterococcus faecalis, Escherichia coli, Bacillus spp., Enterococcus avium, Enterococcus gallinarum, Pseudomonas spp., Alcaligenes spp., Enterobacter spp., Corynebacterium spp., Proteus mirabilis가 동정되었다. 혐기조건 하에서는 E. coli, Clostridium tertium, En. faecalis, P. mirabilis가 동정되었다. 모든 시료에서 E. coli, En. faecalis 혹은 두 가지 모두가 분리되었다. 이러한 정상 황새의 장내 미생물 정보는 향후 분변 배양 결과의 해석에 도움이 될 것으로 판단된다.

• 한국어병학회지
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• 제20권3호
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• pp.221-227
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• 2007

볼락은 산업적 잠재가치가 높은 어종으로 각광받으면서 양식 가능성에 대한 연구가 일부 진행되어 왔으나, 장내세균에 대한 연구는 미미한 실정이었다. 본 연구에서는 전남 돌산도 연안에서 채집된 자연산 볼락과 양식산 볼락의 장내세균총의 분포와 이들 세균들의 약제 감수성에 대하여 조사하였다. 두 분류의 볼락에서 분리된 균주의 16S rDNA 염기를 바탕으로 장내세균을 동정한 결과, 양식산 볼락의 장내에서는 Photobacterium group, Acinetobacter group과 marine sediment bacteria group이 우점하고 있었고, 자연산 볼락의 장내에서는 Photobacterium group Acinetobacter group, Bacillus group, Shewanella group, Staphylococcus group 및 marine sediment bacteria group이 우점하고 있었다. 자연산과 양식산 볼락의 장내세균의 약제 감수성 결과로는 본 연구에서 사용된 9종의 항균제 중 oxytetracycline와 oxolinic acid는 자연산과 양식산이 비슷한 수준의 감수성 나타냈으나, flumequine, erythromycin, norfloxacin, gentamycin, ofloxacin, enrofloxacin 및 ciprofloxacin은 평균 저지대에서 양식산 볼락의 장내세균이 자연산 볼락의 장내세균 보다 약간 낮은 감수성을 보였으나, 자연산 볼락의 장내세균 또한 감수성 시험 대조균주로 사용한 E. coli ATCC9637 보다 현저하게 낮은 감수성을 보였다. 이는 양식현장에서 사용되고 있는 항균물질이 자연 서식 어류생물군의 장내 세균에도 영향을 미칠 수 있음을 시사한다.

• Journal of Microbiology
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• 제44권5호
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• pp.572-576
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• 2006

To obtain primary idea on oral bacterium species that are generally present in periodotally healthy Koreans, the oral bacterial flora in the saliva of four periodontally healthy Koreans at different ages (5, 32, 35, 65) was investigated in this study. For this investigation, 16S rRNA gene clone libraries were generated from the saliva of the four healthy Koreans, and 50 clones were randomly selected from each saliva clone library and sequenced. Totally, 37 different kinds of bacterial 16S rRNA gene sequences were identified based on sequence homology search through GenBank database. The 37 kinds of saliva clone sequences were classified to 14 genera and 2 uncultured and 1 unidentified bacteria. Among the 14 identified genera, Streptococcus, Prevotella, and Veillollella were common genera, and Streptococcus was dominant genus that accounted for 7 different species. Among the seven Streptococcus species, S. salivarius appeared as the most common species. More numbers of species belonging to the genera Streptococcus and Prevotella was present in saliva from ages 32 and 35. While saliva from ages 5 and 65 showed more numbers of species belonging to the genera Rothia, including potential pathogenic species. Overall, saliva of a young child and a senior showed higher bacterial diversity than that of young adults.

• Journal of the Korean Wood Science and Technology
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• 제46권6호
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• pp.713-725
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• 2018

Lower termites require symbiotic microbes in their gut. The microbial communities in the termites must adapt to the termite temperature. Reticulitermes speratus KMT001 from Bukhan Mountain in Seoul may require a special symbiotic microorganisms for growth in low temperature Korean habitat. A metagenomics analysis showed a dramatic change in the symbiotic bacterial flora in the gut of R. speratus KMT001 in response to low temperatures of $4^{\circ}C$ or $10^{\circ}C$. Elusimicrobia, which are endosymbionts of flagellate protists, is the dominant phylum in the termite gut at ${\geq}15^{\circ}C$ but its population decreased drastically at low temperature. Four representative bacterial strains isolated from R. speratus KMT001 in a previous study produced maximum ${\beta}$-glucosidase levels within the temperature range of $10^{\circ}C-30^{\circ}C$. Elizabethkingia sp. BM10 produced ${\beta}$-glucosidase specifically at $10^{\circ}C$. This strain supported the existence of symbiotic bacteria for the low temperature habitat of the termite. This identified bacterium will be a resource for studying low temperature adaptation of termites, studying the gene expression at low temperatures, and developing an industrial cellulase at low temperature.

• Asian-Australasian Journal of Animal Sciences
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• 제33권1호
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• pp.166-176
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• 2020

Objective: An experiment was conducted to determine the effects of L-arginine (L-Arg) and N-carbamoylglutamic acid (NCG) on the growth, metabolism, immunity and community of cecal bacterial flora of weanling and young rabbits. Methods: Eighteen normal-grade male weanling Japanese White rabbits (JWR) were selected and randomly divided into 6 groups with or without L-Arg and NCG supplementation. The whole feeding process was divided into weanling stage (day 37 to 65) and young stage (day 66 to 85). The effects of L-Arg and NCG on the growth, metabolism, immunity and development of the ileum and jejunum were compared via nutrient metabolism experiments and histological assessment. The different communities of cecal bacterial flora affected by L-Arg and NCG were assessed using high-throughput sequencing technology and bioinformatics analysis. Results: The addition of L-Arg and NCG enhanced the growth of weanling and young rabbit by increasing the nitrogen metabolism, protein efficiency ratio, and biological value, as well as feed intake and daily weight gain. Both L-Arg and NCG increased the concentration of immunoglobulin A (IgA), IgM, and IgG. NCG was superior to L-Arg in promoting intestinal villus development by increasing villus height, villus height/crypt depth index, and reducing the crypt depth. The effects of L-Arg and NCG on the cecal bacterial flora were mainly concentrated in different genera, including Parabacteroides, Roseburia, dgA-11_gut_group, Alistipes, Bacteroides, and Ruminococcaceae_UCG-005. These bacteria function mainly in amino acid transport and metabolism, energy production and conversion, lipid transport and metabolism, recombination and repair, cell cycle control, cell division, and cell motility. Conclusion: L-Arg and NCG can promote the growth and immunity of weanling and young JWR, as well as effecting the jejunum and ileum villi. L-Arg and NCG have different effects in the promotion of nutrient utilization, relieving inflammation and enhancing adaptability through regulating microbial community.