• 한국균학회소식:학술대회논문집
• /
• 한국균학회 2014년도 춘계학술대회 및 임시총회
• /
• pp.21-21
• /
• 2014

A edible mushroom, Hypsizygus marmoreus is commercially cultivated in Northeast Asia. Japan's annual production is 110,000ton or more. Since 2002, cultivation is expanded in Korea. To investigate the morphological, cultural and microscopic characteristics of Hypsizygus marmoreus, 109 isolates were collected from Korea and other countries. Clamp connection, chlamydospore and arthrospore were present in all tested isolates of H. marmoreus except HYM-002 and HYM-004. Also pilealtrama, gilltrama, basidia, basidiospore and cystidia of fruiting body were no difference among the isolates in the present investigation. Morphological characteristics of fruiting body was that color of pileus was brown and white, irregular as marble, the average size 12~22mm and stipes was $46{\sim}91{\times}6{\sim}10mm$. Isolates HYM-031, HYM-047 and HYM-109 formed grayish-brown pileus with a faint pattern. Molecular analysis with RAPD and ITS rDNA sequence analysis were also performed to check the genetic relationships among H. marmoreus isolates. Based on the RAPD analysis using the URP-PCR, all isolates of H. marmoreus were clustered into large 3 groups but more than 90% showed high similarity. In addition, morphological and geographical differences have been classified as an independent cluster. The brown and white strains enclosed in same cluster. So genetically no significance difference was observed between these two strains. ITS gene sequences of 16 selected isolates which were 640 bp long, were aligned and compared. The similarity in ITS sequence was 94.8 to 99.1% among tested isolates and the H. marmoreus isolates in GeneBank. In conclusion the tested isolates were H. marmoreus. Morphological and molecular observations proved that all tested isolates were belonging to H. marmoreus. For the stable artificial cultivation, composition of optimum media, mature period and light condition were established. Optimal formula of artificial cultivation medium was Douglas sawdust: corn cob: soybean meal: wheat bran = 40:30:15:15. In addition, 7% rice bran and 3% yellow sucrose was the most effective composition for spawn's liquid medium. For the maturation of the isolates was favorable for growing for 20 to 30 days at $25^{\circ}C$ and the LED lights in mixture of white and blue was good for growth period. For effective growth, the temperature, humidity and aeration control in every step was important.

• The Plant Pathology Journal
• /
• 제24권3호
• /
• pp.269-278
• /
• 2008

Ripe rot was frequently observed on fruits, leaves and stems of grape growing in eight locations in Korea from 2004 to 2006. All 30 isolates of Colletotrichum sp. were obtained from lesions of the ripe rot on grape plants. Out of the isolates, 19 isolates were identified as Colletotrichum acutatum and the others as Colletotrichum gloeosporioides based on morphological and cultural characteristics. Inter and intra specific variations of the Colletotrichum spp. isolates were investigated using RAPD and sequences of rDNA ITS and $\beta$-tubulin-2. Isolates of C. acutatum and C. gloeosporioides were distinctly differentiated by molecular analyses. Phylogenetic trees of ITS and$\beta$-tubulin-2 showed that Korean isolates of C. acutatum were clustered into groups A2 and A3 among the eight global groups. A2 included non-chromogenic isolates and A3 chromogenic ones. Both C. acutatum and C. gloeosporioides isolates were tested for pathogenicity to grape leaves. All isolates tested induced lesions on the leaves of grape by artificial inoculation. There was no difference in pathogenicity between C. acutatum and C. gloeosporioides isolates. This is the first report that C. acutatum except C. gloeosporioides causes grape ripe rot in Korea.

• Journal of Microbiology and Biotechnology
• /
• 제33권2호
• /
• pp.188-194
• /
• 2023

Microbacterium elymi KUDC0405^T was isolated from the rhizosphere of Elymus tsukushiensis from the Dokdo Islands. The KUDC0405^T strain was Gram-stain-positive, non-spore forming, non-motile, and facultatively anaerobic bacteria. Strain KUDC0405^T was a rod-shaped bacterium with size dimensions of 0.3-0.4 × 0.7-0.8 ㎛. Based on 16S rRNA gene sequences, KUDC0405^T was most closely related to Microbacterium bovistercoris NEAU-LLE^T (97.8%) and Microbacterium pseudoresistens CC-5209^T (97.6%). The dDDH (digital DNA-DNA hybridization) values between KUDC0405^T and M. bovistercoris NEAU-LLE^T and M. pseudoresistens CC-5209^T were below 17.3% and 17.5%, respectively. The ANI (average nucleotide identity) values among strains KUDC0405^T, M. bovistercoris NEAU-LLE^T, and M. pseudoresistens CC-5209^T were 86.6% and 80.7%, respectively. The AAI (average amino acid identity) values were 64.66% and 64.97%, respectively, between KUDC0405^T and its closest related type strains. The genome contained 3,596 CDCs, three rRNAs, 46 tRNAs, and three non-coding RNAs (ncRNAs). The genomic DNA GC content was 70.4%. The polar lipids included diphosphatydilglycerol, glycolipid, phosphatydilglycerol, and unknown phospholipid, and the major fatty acids were anteiso-C_17:0 and iso-C_16:0. Strain KUDC0405^T contained MK-12 as the major menaquinone. Based on genotypic, phylogenetic, and phenotypic properties, strain KUDC0405^T should be considered a novel species within the genus Microbacterium, for which we propose the name M. elymi sp. nov., and the type strain as KUDC0405^T (=KCTC 49411^T, =CGMCC1.18472^T).

• Journal of Microbiology and Biotechnology
• /
• 제18권7호
• /
• pp.1290-1297
• /
• 2008

To investigate the diversities of Accumulibacter phosphatis and its polyhydroxyalkanoate (PHA) synthase gene (phaC) in enhanced biological phosphorus removal (EBPR) sludge, an acetate-fed sequencing batch reactor was operated. Analysis of microbial communities using fluorescence in situ hybridization and 16S rRNA gene clone libraries showed that the population of Accumulibacter phosphatis in the EBPR sludge comprised more than 50% of total bacteria, and was clearly divided into two subgroups with about 97.5% sequence identity of the 16S rRNA genes. PAO phaC primers targeting the phaC genes of Accumulibacter phosphatis were designed and applied to retrieve fragments of putative phaC homologs of Accumulibacter phosphatis from EBPR sludge. PAO phaC primers targeting $G_{1PAO},\;G_{2PAO},\;and\;G_{3PAO}$ groups produced PCR amplicons successfully; the resulting sequences of the phaC gene homologs were diverse, and were distantly related to metagenomic phaC sequences of Accumulibacter phosphatis with 75-98% DNA sequence identities. Degenerate NPAO (non-PAO) phaC primers targeting phaC genes of non-Accumulibacter phosphatis bacteria were also designed and applied to the EBPR sludge. Twenty-four phaC homologs retrieved from NPAO phaC primers were different from the phaC gene homologs derived from Accumulibacter phosphatis, which suggests that the PAO phaC primers were specific for the amplification of phaC gene homologs of Accumulibacter phosphatis, and the putative phaC gene homologs by PAO phaC primers were derived from Accumulibacter phosphatis in the EBPR sludge. Among 24 phaC homologs, a phaC homolog (GINPAO-2), which was dominant in the NPAO phaC clone library, showed the strongest signal in slot hybridization and shared approximately 60% nucleotide identity with the $G_{4PAO}$ group of Accumulibacter phosphatis, which suggests that GINPAO-2 might be derived from Accumulibacter phosphatis. In conclusion, analyses of the 16S rRNA and phaC genes showed that Accumulibacter phosphatis might be phylogenetically and metabolically diverse.

• 생명과학회지
• /
• 제20권4호
• /
• pp.487-495
• /
• 2010

Carboxymethylcellulose (CMC)를 분해하는 미생물을 해수에서 분리하였으며, 16S rDNA의 염기서열을 분석하여 동정한 결과, Psychrobacter aquinaris로 학인 되어 P. aquinaris LBH-10로 명명하였다. 이 균주는 CMC, 셀로바이오스, 커드란, 여과지, p-nitrophenyl-$\beta$-D-glucopyranoside (pNPG), 풀루란 및 자일란을 분해하였으나, avicel 및 섬유소는 분해하지 못하였다. P. aquinaris LBH-10이 생산하는 carboxymethylcellulase (CMCase)의 최적 반응 온도는 $50^{\circ}C$이었으며, $20^{\circ}C$에서 $50^{\circ}C$의 온도 범위에서 24시간이 경과한 후에도 90% 이상의 활성을 유지하였다. 또한, 이 균주가 생산하는 CMCase의 최적 반응 pH는 3.5이었으며 pH 2.5에서 pH 7.0 사이의 산성 조건하에서 24시간이 경과한 후에도 70% 이상의 활성을 유지하였다. P. aquinaris LBH-10이 생산하는 CMCase의 최적 반응 pH는 지금까지 발견된 섬유소 분해효소 중에서 가장 낮은 pH로 판단된다. 제한된 농도의 $CoCl_2$, EDTA, 및 $PbCl_2$은 P. aquinaris LBH-10가 생산하는 CMCase의 활성을 증가시켰으나, $HgCl_2$, KCl, $MnCl_2$, $NiCl_2$, 및 $SrCl_2$는 이 균주가 생산하는 CMCase의 활성을 감소시켰다.

• 식물병연구
• /
• 제10권4호
• /
• pp.331-336
• /
• 2004

결구상추에 심각한 피해를 일으키는 균핵병의 생물학적 방제를 위한 기초연구로서 균핵병원균 S. sclerotioum YR-1 대한 우수 길항세균을 선발하고 동정하였다. 건전 결구상추에서 분리한 세균들 중 균핵병원균의 균사생육저지 효과가 큰 10 균주를 길항세균으로 1차 선발하고 이들 일차 길항세균에 의한 방제효과를 생육실내 포트검정한 결과, A-2, A-7 및 RH-4 균주의 방제가가 각각 73.0%, 85.0%, 80.0%이었으며, 이 중 가장 높은 방제가를 보인 A-7 균주를 우수 길항균으로 최종선발하였다. A-7 균주의 생화학적 특성 및 16S rDNA와 gyrA 염기서열을 분석한 결과 Bacillus amyloliquefaciens로 동정되었으며, B. amyloliquefaciens A-7으로 명명하였다.

• Journal of Microbiology and Biotechnology
• /
• 제23권11호
• /
• pp.1509-1518
• /
• 2013

An agar-degrading bacterium, designated as strain $G7^T$, was isolated from a coastal seawater sample from Gaya Island (Gayado in Korean), Republic of Korea. The isolated strain $G7^T$ is gram-negative, rod shaped, aerobic, non-motile, and non-pigmented. A similarity search based on its 16S rRNA gene sequence revealed that it shares 95.5%, 90.6%, and 90.0% similarity with the 16S rRNA gene sequences of Catenovulum agarivorans $YM01^T$, Algicola sagamiensis, and Bowmanella pacifica W3-$3A^T$, respectively. Phylogenetic analyses demonstrated that strain $G7^T$ formed a distinct monophyletic clade closely related to species of the family Alteromonadaceae in the Alteromonas-like Gammaproteobacteria. The G+C content of strain $G7^T$ was 41.12 mol%. The DNA-DNA hybridization value between strain $G7^T$ and the phylogenetically closest strain $YM01^T$ was 19.63%. The genomes of $G7^T$ and $YM01^T$ had an average ANIb value of 70.00%. The predominant isoprenoid quinone of this particular strain was ubiquinone-8, whereas that of C. agarivorans $YM01^T$ was menaquinone-7. The major fatty acids of strain $G7^T$ were Iso-$C_{15:0}$ (41.47%), Anteiso-$C_{15:0}$ (22.99%), and $C_{16:1}{\omega}7c/iso-C_{15:0}2-OH$ (8.85%), which were quite different from those of $YM01^T$. Comparison of the phenotypic characteristics related to carbon utilization, enzyme production, and susceptibility to antibiotics also demonstrated that strain $G7^T$ is distinct from C. agarivorans $YM01^T$. Based on its phenotypic, chemotaxonomic, and phylogenetic distinctiveness, strain $G7^T$ was considered a novel genus and species in the Gammaproteobacteria, for which the name Gayadomonas joobiniege gen. nov. sp. nov. (ATCC BAA-2321 = $DSM25250^T=KCTC23721^T$) is proposed.

• The Plant Pathology Journal
• /
• 제22권3호
• /
• pp.289-294
• /
• 2006

Two isolates of mucous bacteria, mc75 and pc78, were isolated from fungal culture plate as culture contaminants with an interesting swarming motility. Both isolates were identified as Pseudomonas fluorescens based on microscopy, biochemical analysis, Biolog test and DNA sequence analysis of the 16S rRNA gene. Both strains have the exactly the same 16S rRNA gene sequences, and yet their biological control activity were not identical each other. In vitro analysis of antagonistic activity of two isolates against several plant pathogenic fungi indicated that both produced diffusible and volatile antifungal compounds of unknown identities. Treatment of the bacterial culture of P. fluorescens pc78 and its culture filtrate exhibited a strong biological control activity against rice sheath blight in vivo among six plant diseases tested. More effective disease control activity was obtained from treatment of bacterial culture than that of culture filtrate. Therefore, in addition to antifungal compound and siderophore production, other traits such as biofilm formation and swarming motility on plant surface may contribute to the biological control activity of P.fluorescens pc78 and mc75.

• Biotechnology and Bioprocess Engineering:BBE
• /
• 제9권5호
• /
• pp.393-399
• /
• 2004

Useful genes can be Screened from various environments by construction of metagenomic DNA libraries. In this study, water samples were collected from several lakes in mid Korea, and analyzed by T-RFLP to examine diversities of the microbial communities. The crude DNAs r were extracted by the SDS-based freezing-thawing method, and then further purified using an $UltraClean^{TM}$ kit (MoBio, USA). The metagenomic libraries were constructed with the DNAs partially digested with EcoR I, BamH I, and Sac II in Escherichia coli DH 10B using the pBACe3.6 vector. About 44.0 Mb of metagenomic libraries were obtained with average inserts 13-15 kb in size. The bphC genes responsible for degradation of aromatic hydrocarbons via mets-cleavage were identified from the metagenomic libraries by colony hybridization using the bphC specific sequence as a probe. The 2,3-dihydroxybiphenyl (2, 3-DHBP) dioxygenase gene (bphC ), capable of degradation of 2,3-DHBP, was cloned and its nucleotide Sequences analyzed. The genes consisted of 966 and 897 base pairs with an ATG initiation codon and a TGA termination codon. The activity of the 2,3-DHBP dioxygenase was highly expressed to 2,3-DHBP and Showed a broad substrate range to 2,3-DHBP, catechol, 3-methylcatechol and 4-methylcatechol. These results in-dicated that the bphC gene identified from the metagenomes derived from lake water might be useful in the development of a potent strain for degradation of aromatic pollutants.

• Journal of Microbiology and Biotechnology
• /
• 제22권3호
• /
• pp.311-315
• /
• 2012

A novel ${\beta}$-proteobacterium, designated BXN5-$27^T$, was isolated from soil of a ginseng field of Baekdu Mountain in China, and was characterized using a polyphasic approach. The strain was Gram-staining-negative, aerobic, motile, non-spore-forming, and rod shaped. Strain BXN5-$27^T$ exhibited ${\beta}$-glucosidase activity that was responsible for its ability to transform ginsenoside $Rb_1$ (one of the dominant active components of ginseng) to compound Rd. Phylogenetic analysis based on 16S rRNA gene sequences showed that this strain belonged to the family Comamonadaceae; it was most closely related to Ramlibacter henchirensis $TMB834^T$ and Ramlibacter tataouinensis$TTB310^T$ (96.4% and 96.3% similarity, respectively). The G+C content of the genomic DNA was 68.1%. The major menaquinone was Q-8. The major fatty acids were $C_{16:0}$, summed feature 4 (comprising $C_{16:1}$ ${\omega}7c$ and/or iso-$C_{15:0}$ 2OH), and $C_{17:0}$ cyclo. Genomic and chemotaxonomic data supported the affiliation of strain BXN5-$27^T$ to the genus Ramlibacter. However, physiological and biochemical tests differentiated it phenotypically from the other established species of Ramlibacter. Therefore, the isolate represents a novel species, for which the name Ramlibacter ginsenosidimutans sp. nov. is proposed, with the type strain being BXN5-$27^T$ (=DSM $23480^T$ = LMG $24525^T$ = KCTC $22276^T$).