• 한국미생물·생명공학회지
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• 제20권2호
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• pp.219-224
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• 1992

식염농도 3로$15^{\circ}C$에서 발효시킨 물김치에서 젖산균과 효모의 균수변화를 측정한 결과 숙성기까지 효모의 수가 증가한 후 후기에 감소하는 것으로 나타났으며 숙성적기에 효모를 분리동정한 결과 Saccharomyuces sp.가 24주로 대부분을 차지하였으나 Kluyveromyces fragilis 3주, Torulopsis candida 2주도 발견되었다. 이 중에서 S.saitoanus Y17, S.capensis Y29, S.chevalieri Y13, K.fragilis Y2, T.candida Y9를 같은 김치에서 분리한 젖산균 Lactobaccillus plan tarum Lp2, Pediococcus pentosaceus P1, Leuconostoc mesentroides Lu5와 각각 혼합배양하여 효모와 생육에 미치는 영향을 조사한 결과 모두 생육이 억제되었으며, 이는 lacti acid나 H2O2에 의한 억제가 아닌 다른 물질에 의한 것으로 밝혀졌다. 이 세 종류의 젖산균에 의해 영향을 받는 정도는 효모의 종류에 따라 매우 큰 차이를 나타내었다.

• Mycobiology
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• 제51권2호
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• pp.94-108
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• 2023

Termitomyces sp. that grow in symbiosis with fungus-farming Termites have medicinal properties. However, they are rare in nature, and their artificial culture is challenging. The expression of AXL receptor tyrosine kinase and immune checkpoint molecules favor the growth of cancer cells. The study evaluated the optimal conditions for the artificial culture of Termitomyces and their inhibitory activity on AXL and immune checkpoint molecules in lung adenocarcinoma and melanoma cell lines. The culture of 45 strains of Termitomyces was compared. Five strains with marked growth rates were selected. Four of the selected strains form a single cluster by sequence analysis. The mycelium of 4 selected strains produces more fungal mass in potato dextrose broth than in a mixed media. The bark was the most appropriate solid substrate for Termitomyces mycelia culture. The mycelium of all five selected strains showed a higher growth rate under normal CO₂ conditions. The culture broth, methanol, and ethyl acetate of one selected strain (T-120) inhibited the mRNA relative expression of AXL receptor tyrosine kinase and immune checkpoint molecules in cancer cell lines. Overall, these results suggest the potential usefulness of Termitomyces extracts as a coadjuvant therapy in malignant diseases.

• Journal of Microbiology and Biotechnology
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• 제10권6호
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• pp.881-884
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• 2000

A polymerase chain reaction (PCR) was performed to rapidly identify Lactobacillus plantarum from type strains and kimchi samples. The PCR experiments were carried out using specific oligonucleotide primer sets based on the 16S rRNA gene sequences of L. plantarum. The expected DNA amplificate of 419 bp was obtained when either purified DNA or whole cells of L. plantarum strains reacted with LP primers, yet not with any of the other strains. The PCR product was confirmed by DNA sequencing. Accordingly, since the PCR method used is simple, specific, and rapid, it will be useful for monitoring and evaluation L. plantarum in the mixed microbial population found in kimchi.

• 한국습지학회지
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• 제19권4호
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• pp.443-450
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• 2017

이 연구의 목적은 유해한 남세균인 Microcystis aeruginosa를 생물학적으로 제어하기 위해 남세균생장 억제미생물을 분리하고 그 효과를 조사하는 것이다. 이 연구에서 다양한 남세균생장 억제미생물이 분리되었고, 이중에서 M. aeruginosa의 생장을 효과적으로 억제하는 M1, M2, M3, M4로 명명된 4종의 균주를 분리하였다. 16S rRNA을 통해 동정된 M1~M4 균주는 모두 간균이고 그램 음성으로 나타났다. 분리된 단일종 뿐만 아니라, 혼합된 M1~M4 균주 4종의 공동배양이 M. aeruginosa를 효과적으로 처리하였다. 혼합 균주의 접종 2일 후에 약 50%의 클로로필 a가 감소되었고, 4일 후에 약 70%, 7일 후에 약 80%의 클로로필 a가 감소되었다. 이들 결과는 M1~M4 남세균생장 억제 균주가 유해한 M. aeruginosa를 제어하는데 기여할 것으로 생각된다.

• 한국미생물·생명공학회지
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• 제27권2호
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• pp.145-152
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• 1999

Brettanomyces custersii CBS 5512 which has reported as a thermotolerant glucose-cellobiose co-fermentable yeast strain was mutated with UV and NTG to improve ethanol yield at higher than 4$0^{\circ}C$ B. custersii H1-23, H1-39, H1-55 and H1062 were finally selected for hyper-fermentable strains at higher than 4$0^{\circ}C$ from thermotolerant 7510 colonies through 5th selection. Among the selected strains, H1-39 mutant had better fermentability at 4$0^{\circ}C$ and 43$^{\circ}C$ from different concentrations of glucose. H1-39 and H1-23 mutants yielded more than 70% of the theoretical ethanol yield in 4 and 8% mixed sugars at above 4$0^{\circ}C$, which was 5-11% higher than those by original strain. Especially, H1-39 mutant had better fermentability in 4% mixed sugar. It showed 78.5% of the theoretical yield at 4$0^{\circ}C$ and 72.2% of the theoretical yield at 43$^{\circ}C$. On the other hand, theoretical yield of ethanol by H1-39 mutant in 8% mixed sugar at 4$0^{\circ}C$ and 43$^{\circ}C$ were 75.2% and 70.2%, respectively. Theses values increased up to 7-11% as compared to those by orginal strain. By the simultaneous saccharification and fermentation, ethanol production by H1-39 mutant increased up to more than 23% as compared to that by original strain.

• 한국식품과학회지
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• 제6권4호
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• pp.219-230
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• 1974

국내외에서 수집한 유침 및 유전지대의 토양시료에서 n-paraffin자화성균주와 ethanol자화성균주를 분리하여 혼합배양을 시도하였고 선정된 균주에 대해서는 등정과 아울러 최적배지조성을 검토하였다. 최종적으로 선정된 균주중 n-paraffin자화성균주(strain No. 76)는 Candida tropicalis var. KIST 76으로, ethanol 자화성균주 (Strain No. 76H)는 Trichosporn cutaneum KIST 76H로 동정되었다. 최적배지조성에서 Candida tropicalis var. KIST 76을 단독배양하였을때 건조균체량은 배양 16시간 후에 16 g/l(대기질당 수율 71.1%), 이때의 단백질함량은 53.4%였으나 Candida tropicalis var. KIST 76과 Trichosporn cutaneum KIST 76H와 혼합배양하면 배양 12시간 후에 건조균체량은 20g/l(대기질당 수율 88.8%), 단백질 함량은 58.0%로 증가하였다.

• Parasites, Hosts and Diseases
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• 제51권4호
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• pp.401-412
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• 2013

Because of an increased number of Acanthamoeba keratitis (AK) along with associated disease burdens, medical professionals have become more aware of this pathogen in recent years. In this study, by analyzing both the nuclear 18S small subunit ribosomal RNA (18S rRNA) and mitochondrial 16S rRNA gene loci, 27 clinical Acanthamoeba strains that caused AK in Japan were classified into 3 genotypes, T3 (3 strains), T4 (23 strains), and T5 (one strain). Most haplotypes were identical to the reference haplotypes reported from all over the world, and thus no specificity of the haplotype distribution in Japan was found. The T4 sub-genotype analysis using the 16S rRNA gene locus also revealed a clear subconformation within the T4 cluster, and lead to the recognition of a new sub-genotype T4i, in addition to the previously reported sub-genotypes T4a-T4h. Furthermore, 9 out of 23 strains in the T4 genotype were identified to a specific haplotype (AF479533), which seems to be a causal haplotype of AK. While heterozygous nuclear haplotypes were observed from 2 strains, the mitochondrial haplotypes were homozygous as T4 genotype in the both strains, and suggested a possibility of nuclear hybridization (mating reproduction) between different strains in Acanthamoeba. The nuclear 18S rRNA gene and mitochondrial 16S rRNA gene loci of Acanthamoeba spp. possess different unique characteristics usable for the genotyping analyses, and those specific features could contribute to the establishment of molecular taxonomy for the species complex of Acanthamoeba.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2018년도 추계학술대회
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• pp.113-113
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• 2018

Endophthalmitis is a disease that causes ocular inflammation and has a catastrophic effect on eyesight. Recent studies show that Enterococcus faecalis is rapidly increasing causative bacterium of endophthalmitis. It is predicted that the increased endophthalmitis by E. faecalis is presumable due to the high resistance of E. faecalis to moxifloxacin (MFX), which is a common antibiotic used for eye drop. Because of the need for therapeutic agents to overcome this problem, this study sought to explore the feasibility of developing a combination therapy using Orostachys japonicus. The ethylacetate fraction of O. japonicus (OJA) used in this study. Antimicrobial activity was tested 13 E. faecalis strains including one E. faecalis standard strain, eight clinically isolated E. faecalis strains and four quinolone resistant E. faecalis strains using CLSI antibiotic susceptibility test method. Minimal Inhibitory Concentration (MIC) of OJA was confirmed to be $500{\mu}g/ml$ for all 13 strains. Then we tested for the synergistic effect of OJA to MFX using checkboard test method. The MIC of MFX was $0.25{\mu}g/ml$ for the standard strain and 8 for the clinical isolates, and $16{\sim}64{\mu}g/ml$ for the quinolone - resistant strains. When OJA was mixed with MFX, no synergistic effect was observed in all strains, but the antibacterial activity of OJA remained unchanged. Most ocular other strains can be removed by MFX except the MFX resistant E. faecalis, which can be removed by OJA in combination therapy. Therefore, OJA can be a potential candidate for the combined treatment endophthalmitis.

• 한국미생물·생명공학회지
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• 제49권1호
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• pp.120-129
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• 2021

Rotavirus A (RVA) is recognized as a major etiology responsible for the development of acute gastroenteritis in children worldwide. The purpose of the present study was to perform the molecular characterization of RVA. A total of 323 stool specimens collected from hospitalized children with acute gastroenteritis in Chiang Rai, Thailand, in 2016-2018 were identified for G- and P-genotypes through RT-PCR analysis. RVA was more prevalent in 2017-2018 (37.8%) than in 2016-2017 (23.2%). The seasonal peak of RVA occurred from March to April. G3P[8] was predominant in 2016-2017 (90.6%) and 2017-2018 (58.6%). Other genotypes including G1P[8], G8P[8], G9P[8], and mixed infections were also identified. G3P[8] strains clustered together in the same lineage with other novel human equine-like G3P[8] strains previously identified in multiple countries and presented a genotype 2 constellation (G3-P[8]-I2-R2-C2-M2-A2-N2-T2-E2-H2). Several amino acid differences were observed in the antigenic epitopes of the VP7 and VP8* capsid proteins of the equine-like G3P[8] compared with those of the RVA vaccine strains. The homology modeling of the VP7 and VP8* capsid proteins of the equine-like G3P[8] strains evidently exhibited that these residue differences were present on the surface-exposed area of the capsid structure. The emergence of the equine-like G3P[8] strains in Thailand indicates the rapid spread of strains with human and animal gene segments. Continuous surveillance for RVA is essential to monitor genotypes and genetic diversity, which will provide useful information for selecting rotavirus strains to develop a safe and effective RVA vaccine that is efficacious against multiple genotypes and variants.

• 산업기술연구
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• 제28권A호
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• pp.141-147
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• 2008

Several contaminated bacteria such as Lactobacillus brevis and Pediococcus damnosus in beer production cause beer spoilage by producing off flavours and turbidity. Detection of these organisms is complicated by the strict anaerobic conditions and lengthy incubation times required for their cultivation, consequently there is a need for more rapid detection methods. Recently, two contaminated strains were isolated from vessel of beer production and identified as Lactobacillus species by API kit identificaton as well as 16S-23S ITS sequencing analyses. Two isolated strains were named as Lactobacillus sp. HLA1 and Lactobacillus HLB2, respectively. A polymerase chain reaction (PCR) method was developed for the rapid and specific detection of Lactobacillus sp.. Two sets of primer pairs (HLA1-F/HLA1-R and HLB2-F/HLB2-R) were designed for the amplification of a 1576 base pair (bp) fragment of the HLA1 16S-23S rRNA gene and 1888 bp fragement of the HLB2 16S-23S rRNA. Amplified PCR products were highly specific to detect corresponding bacteria when other contaminated strains were used as PCR templates. However, detection of both strains were limited when $100{\mu}{\ell}$ of cultured samples were mixed with $100m{\ell}$ of beer sample in arbitrary manner. The sensitivity of the assay still needs to be improved for direct detection of the small amounts of bacteria present in beer.