• 미생물학회지
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• 제46권2호
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• pp.177-182
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• 2010

2009년 4월 제주도의 운진항에서 채집한 해양 해면 Spirastrella abata와 Cinachyrella sp.의 공생 세균의 주요 군집구조를 16SrDNA-denaturing gradient gel electrophoresis (DGGE) 방법을 이용하여 비교 분석하였다. S. abata와 Cinachyrella sp.는 각각 7개와 8개의 DGGE 밴드를 나타내었으며 이들을 적출하여 염기서열을 분석한 결과, NCBI에 등록된 서열들과 92-100%의 유사도를 나타내었다. S. abata의 주요 공생세균은 Alphaproteobacteria와 Deltaproteobacteria에 속하였으며, Cinachyrella sp.의 경우 Alphaproteobacteria, Gammaproteobacteria와 Actinobacteria에 속하는 세균으로 구성되었다. 두 종의 해면에서 공통되는 공생세균 그룹은 Alphaproteobacteria였으며 이 세균 그룹은 두 종의 해면 모두에서 우점하였다. Deltaproteobacteria는 S. abata에서, Actinobacteria와 Gammaproteobacteria는 Cinachyrella sp.에서만 관찰되었다. 동일지역에서 채집한 서로 다른 두 종의 해면은 각각 다른 공생세균 군집구조를 나타내었다.

• Journal of Microbiology and Biotechnology
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• 제22권6호
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• pp.729-735
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• 2012

The PCR-RFLP method has been useful for detection of known genes and identification of novel genes. In the present study, degenerate primers were designed from five groups of cry1 genes for PCR-RFLP analysis. Bacillus thuringiensis (Bt) isolates from different regions were evaluated for PCR amplification of various cry1 genes using newly designed primers and cry2 genes using reported primers. PCR analysis showed an abundance of cry1A genes and especially cry1Ac genes in isolates from all regions. RFLP analysis revealed the presence of multiple cry1A genes in isolates from central and southern regions. Unique digestion patterns of cry1A genes were observed in isolates from each region. Few of the isolates represented a digestion pattern of cry1A genes that did match to any of the known cry1A genes. RFLP analysis suggested an abundance of cry2Ab along with a novel cry2 gene in Bt isolates from different regions of India. Sequence analysis of the novel cry2 gene revealed 95% sequence identity to cry2Ab and cry2Ah genes. Phylogenetic analysis revealed that the novel cry2 gene could have diverged earlier than the other cry2 genes. Our results encourage finding of more diverse cry2 genes in Bt isolates. Rarefaction analysis was used to compare cry1A gene diversity in isolates from different soil types. It showed a higher degree of cry1A gene diversity in isolates from central region. In the present study, we propose the use of novel degenerate primers for cry1 genes and the PCR-RFLP method using a single enzyme to distinguish multiple cry1A and cry2 genes as well as identify novel genes.

• Journal of Microbiology and Biotechnology
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• 제27권7호
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• pp.1288-1299
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• 2017

Composting is widely used to transform waste into valuable agricultural organic fertilizer. Anaerobic ammonium-oxidizing (anammox) bacteria play an important role in the global nitrogen cycle, but their role in composting remains poorly understood. In the present study, the community structure, diversity, and abundance of anammox bacteria were analyzed using cloning and sequencing methods by targeting the 16S rRNA gene and the hydrazine oxidase gene (hzo) in samples isolated from compost produced from cow manure and rice straw. A total of 25 operational taxonomic units were classified based on 16S rRNA gene clone libraries, and 14 operational taxonomic units were classified based on hzo gene clone libraries. The phylogenetic tree analysis of the 16S rRNA gene and deduced HZO protein sequences from the corresponding encoding genes indicated that the majority of the obtained clones were related to the known anammox bacteria Candidatus "Brocadia," Candidatus "Kuenenia," and Candidatus "Scalindua." The abundances of anammox bacteria were determined by quantitative PCR, and between $2.13{\times}10^5$ and $1.15{\times}10^6$ 16S rRNA gene copies per gram of compost were found. This study provides the first demonstration of the existence of anammox bacteria with limited diversity in cow manure composting.

• 미생물학회지
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• 제34권4호
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• pp.194-199
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• 1998

한강의 본류와 만나는 탄천과 중랑천에서 16S rDAN를 증폭하고 부분적인 염기서열 분석을 통하여 한강의 세균 다양성을 결정하였다. 총 27개의 클론을 분리하였으며 RFLP를 이용하여 7개의 group으로 나누었다. 탄천의 15개 클론은 4개의 group으로 나뉘어졌으며 가장 많은 클론을 포함하는 group(HT-1 클론)은 class Proteobacteria의 ${\delta}$-subdivision에 속하는 Acrobacter cryaerophilius와 높은 유사도를 보였으며, 다른 두 group(HT-6과 HT-9 클론)은 모두 clas Cytophagales에 속하였다. 중랑천의 12개의 클론은 3개의 group으로 나뉘어졌으며 가장 많은 클론을 보이는 group(HJ-1 클론)은 class Proteobacteria의 ${\alpha}$-subdivision에 속하는 Sphingomonas sp. 와 높은 유사도를 나타내었다. 전체적으로는 Proteobateria(alpha, beta and delta subdivision), Cytophagales와 Actinomycetales가 검출되었다.

• Parasites, Hosts and Diseases
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• 제58권2호
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• pp.181-184
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• 2020

Blastocystis, an enteric protist, has been reported to be an important cause of protozoal gastrointestinal manifestations in humans and animals worldwide. Animals harboring certain Blastocystis subtypes (STs) may serve as a potential source of human infection. However, information about the prevalence and genetic diversity of Blastocystis in alpacas is limited. In the present study, a total of 366 fecal samples from alpacas in Shanxi Province, northern China, were examined for Blastocystis by PCR amplification of the small subunit rRNA gene, followed by sequencing and phylogenetic analysis. The prevalence of Blastocystis in alpacas was 23.8%, and gender difference in the prevalence of Blastocystis was observed. The most predominant Blastocystis ST was ST10, followed by ST14 and ST5. The detection of ST5, a potentially zoonotic genotype, indicates that alpacas harboring ST5 could be a potential source of human infection with Blastocystis. These data provide new insight into the prevalence and genetic diversity of Blastocystis in alpacas.

• Journal of Photoscience
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• 제9권3호
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• pp.45-48
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• 2002

Microbial rhodopsins, photoactive 7-transmembrane helix proteins that use retinal as their chromophore, were observed initially in the Archaea and appeared to be restricted to extreme halophilic environments. Our understanding of the abundance and diversity of this family has been radically transformed by findings over the past three years. Genome sequencing of cultivated microbes as well as environmental genomics have unexpectedly revealed archaeal rhodopsin homologs in the other two domains of life as well, namely Bacteria and Eucarya. Organisms containing these homologs inhabit such diverse environments as salt flats, soil, freshwater, and surface and deep ocean waters, and they comprise a broad phylogenetic range of microbial life, including haloarchaea, proteobacteria, cyanobacteria, fungi, and algae. Analysis of the new microbial rhodopsins and their expression and structural and functional characterization reveal that they fulfill both ion transport and sensory functions in various organisms, and use a variety of signaling mechanisms. We have obtained the first crystallographic structure for a photosensory member of this family, the phototaxis receptor sensory rhodopsin II (SRII, also known as phoborhodopsin) that mediates blue-light avoidance by the haloarchaeon Natronobacterium pharaonis. The structure obtained from x-ray diffraction of 3D crystals prepared in a cubic lipid phase reveals key features responsible for its spectral tuning and its sensory function. The mechanism of SRII signaling fits a unified model for transport and signaling in this widespread family of phototransducers.

• 한국균학회지
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• 제47권3호
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• pp.199-208
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• 2019

한라산 상부와 하부에 서식하는 구상나무와 주목의 뿌리에서 각각 외생균근균의 군집 구조를 분석하였다. 형태적 특징과 분자적 분석을 통해 구상나무에서는 하부에서 6속 8종, 상부에서 7속 10종의 외생균근균을 확인하였다. 주목에서는 하부에서 4속 8종, 상부에서 6속 10종의 외생균근균을 확인하였다. 외생균근균의 종 다양성 지수, 종 균등도, 종 수는 숙주식물과 관계없이 상부에서 높게 나타난 반면, 균투 수는 하부에서 높게 나타났다. 하부와 상부에서 구상나무와 주목 뿌리의 외생균근균 군집 간의 유사도를 분석한 결과, 고도에 관계없이 구상나무의 뿌리에서 발견된 외생균근균 군집 간의 유사도가 주목 뿌리의 외생균근균 군집 간 유사도나 구상나무 뿌리의 외생균근균 군집과 주목의 뿌리 외생균근균 군집 간의 유사도에 비해 더 높게 나타났다. 이는 구상나무가 주목과는 다른 특이한 외생균근균 군집 구조를 이루고 있으며, 기온 상승으로 멸종 위기에 처한 구상나무의 보전과 자생지 관리에 도움을 줄 수 있을 것으로 판단된다.

• Parasites, Hosts and Diseases
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• 제57권5호
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• pp.525-529
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• 2019

Blastocystis is one of the most commonly detected genera of protozoan parasites in the human intestines as well as the intestines of many other species such as pigs in several geographical regions worldwide. However, no studies have examined Blastocystis in pigs in Korea. In this study, PCR and nucleotide sequencing were performed to evaluate the genetic diversity and zoonotic potential of Blastocystis using pig fecal samples. We obtained 646 stool samples from groups of piglets, weaners, growers, finishers, and sows in Korea. A total of 390 Blastocystis-positive samples were identified, and the infection rate was 60.4%. The infection rates were significantly related to age and region. The 4 subtypes (STs) of Blastocystis confirmed by phylogenetic analysis were ST1, ST2, ST3, and ST5, indicating the high genetic diversity of Blastocystis in Korean pigs. ST5 was highly distributed in Korean pigs among detected STs in this study. Some sequences were closely related to those of Blastocystis isolated from humans. This is the first study of Blastocystis in pigs in Korea. Based on the results, Blastocystis is prevalent in Korean pigs. Although a small number of samples were obtained in some areas, the clinical development of Blastocystis infection in pigs and potential for human transmission should be further examined.

• Asian-Australasian Journal of Animal Sciences
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• 제32권11호
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• pp.1715-1724
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• 2019

Objective: As laying hens become aged, laying performance and egg quality are generally impaired. One of the practical methods to rejuvenate production and egg quality of aged laying hens with decreasing productivity is a forced molting. However, the changes in intestinal microbiota after forced molting of aged hens are not clearly known. The aim of the present study was to analyze the changes in excreta bacterial communities after forced molting of aged laying hens. Methods: A total of one hundred 66-wk-old Hy-Line Brown laying hens were induced to molt by a 2-d water removal and an 11-d fasting until egg production completely ceased. The excreta samples of 16 hens with similar body weight were collected before and immediately after molting. Excreta bacterial communities were analyzed by high-throughput sequencing of bacterial 16S rRNA genes. Results: Bacteroidetes, Firmicutes, and Proteobacteria were the three major bacterial phyla in pre-molting and immediate post-molting hens, accounting for more than 98.0%. Lactobacillus genus had relatively high abundance in both group, but decreased by molting (62.3% in premolting and 24.9% in post-molting hens). Moreover, pathogenic bacteria such as Enterococcus cecorum and Escherichia coli were more abundant in immediate post-molting hens than in pre-molting hens. Forced molting influenced the alpha diversity, with higher Chao1 (p = 0.012), phylogenetic diversity whole tree (p = 0.014), observed operational taxonomic unit indices (p = 0.006), and Simpson indices (p<0.001), which indicated that forced molting increased excreta bacterial richness of aged laying hens. Conclusion: This study improves the current knowledge of bacterial community alterations in the excreta by forced molting in aged laying hens, which can provide increasing opportunity to develop novel dietary and management skills for improving the gastrointestinal health of aged laying hens after molting.

• ALGAE
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• 제34권3호
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• pp.217-228
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• 2019

The marine brown algal genus Colpomenia has a worldwide distribution, with five species reported in Korea and Japan. However, no studies to date attempted to identify the number of species and geographical distribution of Colpomenia along Chinese coast. To fill the biodiversity knowledge gap, we analyzed 63 mitochondrial cox3 and 62 mitochondrial atp6 sequences of Colpomenia specimens collected from 30 localities along the Chinese coast. Maximum likelihood and Bayesian inference trees suggest the presence of at least three Colpomenia species (i.e., C. peregrina, C. claytoniae, and C. sinuosa) in China. C. peregrina and C. claytoniae are documented for the first time. C. sinuosa was only found in the South China Sea and its distribution didn't overlap with that of C. peregrina which was found in the Yellow-Bohai Sea and the East China Sea. C. claytoniae appears to be confined to three isolated islands in the East and the South China Sea, where it occurs in sympatry with, respectively, C. peregrina and C. sinuosa. Future study can focus on comparing eco-physiological differences of Colpomenia species in response to environmental variables and exploring possible genetic hybridization / introgression at inter-specific contact zones.