• Mycobiology
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• 제50권1호
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• pp.55-65
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• 2022

Lichen is a symbiotic mutualism of mycobiont and photobiont that harbors diverse organisms including endolichenic fungi (ELF). Despite the taxonomic and ecological significance of ELF, no comparative investigation of an ELF community involving isolation of a pure culture and high-throughput sequencing has been conducted. Thus, we analyzed the ELF community in Parmotrema tinctorum by culture and metabarcoding. Alpha diversity of the ELF community was notably greater in metabarcoding than in culture-based analysis. Taxonomic proportions of the ELF community estimated by metabarcoding and by culture analyses showed remarkable differences: Sordariomycetes was the most dominant fungal class in culture-based analysis, while Dothideomycetes was the most abundant in metabarcoding analysis. Thirty-seven operational taxonomic units (OTUs) were commonly observed by culture-and metabarcoding-based analyses but relative abundances differed: most of common OTUs were underrepresented in metabarcoding. The ELF community differed in lichen segments and thalli in metabarcoding analysis. Dissimilarity of ELF community intra lichen thallus increased with thallus segment distance; inter-thallus ELF community dissimilarity was significantly greater than intra-thallus ELF community dissimilarity. Finally, we tested how many fungal sequence reads would be needed to ELF diversity with relationship assays between numbers of lichen segments and saturation patterns of OTU richness and sample coverage. At least 6000 sequence reads per lichen thallus were sufficient for prediction of overall ELF community diversity and 50,000 reads per thallus were enough to observe rare taxa of ELF.

• International Journal of Advanced Culture Technology
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• 제11권3호
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• pp.260-267
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• 2023

We aimed to investigate the proportions of MTB- and NTM-positive tests and the distribution patterns of species isolated by contracted testing agencies in South Korea. Respiratory specimens submitted to contracted testing agencies in South Korea for AFB culture from January 2014 to December 2021 were included (533,713 specimens in total). Trends based on MTB and NTM detection, patient sex and age, culture medium type, and testing year were analyzed. MTB and NTM positive detection increased in the patients. The average ages of MTB- and NTM-positive patients increased in those aged ≥61 years. For solid culture, the MTB detection rate decreased from 5.9% in 2014 to 3.3% in 2018 and increased to 4.7% in 2021; the NTM detection rate increased from 2.1% in 2014 to 3.4% in 2018 and 3.7% in 2021. For liquid culture, the MTB detection rate decreased from 8.3% in 2014 to 5.5% in 2018 and increased to 6.0% in 2021; the NTM detection rate increased from 3.5% in 2014 to 5.5% in 2018 and decreased to 5.3% in 2021. An isolation ratio reversal between MTB and NTM was observed in 2018. In this study, we provide information on mycobacterial isolation rates and species distributions using AFB culture test results from Korea's referral laboratories. Increased MTB- and NTM-isolation rates were observed in individuals aged ≥60 years, indicating the need for regular testing and focused management for them. Expanding liquid culture applications, which show higher positivity rates than solid culture methods, is necessary.

• Journal of Microbiology and Biotechnology
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• 제3권1호
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• pp.57-60
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• 1993

The herbicidal compound, 3D5 was isolated from the culture broth of strain 3D5, a soil isolate. Based on taxonomic studies, this culture was identified as Streptomyces sp. 3D5.

• KSBB Journal
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• 제13권5호
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• pp.518-523
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• 1998

A large quantity of ethylene glycol(EG) is remained in the effluent after pretreating polyester weight-loss wastewater physicochemically in the fist stage and must be treated biologically in the second stage. Therefore, an excellent EG-utilizing bacteria strain was isolated from the natural system and the optimal culture conditions of the strain were investigated. The optimal culture conditions of temperature, pH, and nitrogen source were found to be 35$^{\circ}C$, 7.5 and ammonium chloride, respectively, when CODCr removal efficiency was more than 90%. The growth of stains and EG removal efficiency was slightly improved by adding elements such as niacin and biotin. With increasing inoculation size in a batch culture, the removal efficiency of EG was conspicuously increased. Growth rate was inhibited when the initial concentration of EG was more then 30g/L. The strain was identified as Pseudomonas sp. based on morphological and biological characteristics and named as Pseudomonas sp. EG1.

• The Plant Pathology Journal
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• 제34권3호
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• pp.157-162
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• 2018

The objective of this work was to accomplish the isolation, molecular identification and characterizing the physiology of the causal agent of the algal spot in mango trees. For this purpose, the pathogen growth was assessed in different culture media, with subsequent observation and measurements of the filamentous cells. The molecular identification was made using mycelium obtained from leaf lesions and pure algae colonies grown in culture medium. Descriptions based on DNA sequencing indicated that the algae is Cephaleuros virescens. The algae must be isolated primarily in liquid medium for further pricking into agar medium. The highest mycelial growth average in Petri dishes occurred when the algae were grown in Trebouxia and BBM. Trebouxia enabled larger cells in the filamentous cells when compared to other culture media.

• Asian-Australasian Journal of Animal Sciences
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• 제22권2호
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• pp.187-193
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• 2009

The present study identified the favorable conditions for isolation, enrichment and in vitro culture of highly purified, undifferentiated pig spermatogonial stem cell (SSC) lines that proliferate for long periods of time in culture. The colonies displayed morphology similar to miceSSC and were positive for markers of SSC (PGP9.5), proliferating germ cell (PigVASA), pre-meiotic germ cell (DAZL) and pluripotency (OCT4, SSEA-1, NANOG, and SOX2) based on immuno-cytochemistry and RT-PCR. The purity of these colonies was confirmed by negative expression of markers for sertoli cell (GATA4 and SOX9), peritubular myoid cell (${\alpha}$-SMA), differentiating spermatogonial and germ cells (c-KIT). The colonies could be maintained with undifferentiated morphology for more than two months and passaged more than 8 times with doubling time between 6-7 days. Taken together, we conclude that pigSSC could be successfully isolated and cultured in vitro and they possess characteristics similar to miceSSC.

• 한국작물학회지
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• 제47권1호
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• pp.62-67
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• 2002

An efficient system of rice microspore culture could contribute to the production of genetically modified rice. The microspores were isolated by mechanical or shed methods. The number of microspores per 100 anthers isolated at uninucleate stage was higher than (or similar to) those at binucleate stage in isolation method with pestle or spatular, but microspore divisions were not easily observed on both stages. On the other hand, pollen division in shed pollen culture was observed more frequently at uninuclear than at binuclear stage. Cold pretreatment at 1$0^{\circ}C$ for 10 days resulted in the best multicellular division to produce microcalli at 12.5% efficiency in shed microspores. Heat shock at 33$^{\circ}C$ for one hour before or after pollen shedding enhanced cell division and callus formation. Out of twelve green regenerants, two were haploids and ten were diploids based on the chromosome analysis of root tips. The size of stoma was 12$^{m}$ m in haploids and 15 ${\mu}{\textrm}{m}$ in diploids determined by scanning electron microscope (SEM).

• Fisheries and Aquatic Sciences
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• 제15권3호
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• pp.259-263
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• 2012

To isolate an alginate-degrading bacterium, we conducted a single colony isolation using a solid medium containing alginate as the sole carbon source. A marine bacterium Y-4 capable of degrading alginate was isolated from seawater. The strain was identified to be Pseudoalteromonas sp., based on morphological, biochemical, 16S rDNA homology, and phylogenetic analyses. Moreover, Pseudoalteromonas sp. Y-4 exhibited alginate lyase activity in the presence of 4% alginate even though many known alginate-degrading bacteria degrade in the range of 0.5-1% alginate. The optimum culture conditions for the Y-4 strain were 2% alginate, pH 8.0, and 3% NaCl at $30^{\circ}C$. The highest alginate lyase activity was also observed under the same conditions. To our knowledge, this is the first reported isolation of a marine bacterium degrading high concentrations of alginate.

• 펄프종이기술
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• 제35권1호
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• pp.34-40
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• 2003

This study was carried out to select the useful bacteria which secret extracellula enzymes for enzymatic deinking agent of old newspaper. CMCase, FPase and xylanase activities of the bacteria liquid culture were measured at optimal growth conditions. Clear zone test was checked on the solid culture. The results of this study were as follow: Eight strains of 28 bacteria isolated from a paper mill soil ground were shown strong CMCase and xylanase activity with the clear zone test. The optimal pH and temperature for culture growth were 6~8 and 26~$34^{\circ}C$, respectively and optimal culture period were less than 60 hours. Based on CMCase, FPase and xylanase activity, strain No. 18, 21, 22 and 28 which were relatively higher than the other strains, were selected for further enzymatic deinking research.

• 한국미생물·생명공학회지
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• 제29권3호
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• pp.134-141
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• 2001

경기도 일대의 가금류 공장부근 토양로부터 단백질 분해활성이 높은 균주를 분리한 후 이것들 가운데 Keratinolytic protease 생산성이 우수한 균주는 KP-364를 선별하여 효소생산을 위한 최적 배양조건을 검토하였다. 선별된 KP-364 는 형태학적 생화학적 특성을 종합한 결과 Pseudomonas sp 로 동정되었으며 편의상 Pseudomonas sp. KP-364로 명명하였다. 효소생산을 위한 최적 배지조성은 Keratin 0.1% glucose 2.0% soybeam meal 0.5% NaNO3 0.5% KCI 0.2%이었고 초기 pH 6.5 배양온도 $37^{\circ}C$, 48시간진탕 배양할때 효소생산이 가장 우수하였으며 이때의 효소의 역가는 1,270 U/ml/hr이었다.