Succession of bacterial community structure during the early stage of biofilm development in the Antarctic marine environment

이영미,조경희,황규인,김은혜,김민철,홍순규,이홍금,Lee, Yung Mi,Cho, Kyung Hee,Hwang, Kyuin,Kim, Eun Hye,Kim, Mincheol,Hong, Soon Gyu,Lee, Hong Kum The Microbiological Society of Korea 2016 미생물학회지 Vol.52 No.1

부유 세균의 군집과 구별되는 생물막내 세균 군집은 다양한 수생태계에서 중요한 생태학적 역할을 수행한다. 자연계에서 생물막이 생태학적으로 중요함에도 불구하고, 남극 해양 환경에서 생물막 형성 과정 동안의 세균 군집 구조와 그들의 변화에 대한 연구는 수행되지 않았다. 본 연구에서, 남극 해양 환경에서 생물막 형성 초기 단계에서의 세균 군집 구조 변화를 16S rRNA 유전자의 pyrosequencing을 통해 수행하였다. 생물막내 전반적인 세균 군집은 주변의 해수의 군집과 매우 달랐다. 전체 세균 군집의 78.8%에서 88.3%를 차지한 Gammaproteobacteria와 Bacteroidetes의 상대적 풍부도는 생물막의 형성에 따라 급격하게 변하였다. Gammaproteobacteria는 생물막 형성 진행에 따라 증가하다가 (4일째에 75.7%), 7일째에 46.1%로 감소하였다. 반면, Bacteroidetes는 초기에서 중기로 갈수록 감소하다가 다시 증가하는 양상을 보이며, Gammaproteobacteria와 반대의 변화 양상을 나타내었다. 생물막 형성의 초기 과정에 우점 하는 OTU (>1%)들의 변화 양상은 시기에 따라 뚜렷한 차이를 보였다. Gammaproteobacteria에 속하는 종의 경우, 4일째까지 증가한 반면, 첫째날 가장 우점 하였던 문인 Bacteroidetes에 속하는 종은 4일째까지 감소한 후, 다시 증가하는 양상을 보였다. 흥미롭게, Pseudoalteromonas prydzensis가 67.4%를 차지하며 우점 하였는데, 이는 생물막 형성에 이 종이 중요한 역할을 수행함을 시사하는 것으로 보인다. Compared to planktonic bacterial populations, biofilms have distinct bacterial community structures and play important ecological roles in various aquatic environments. Despite their ecological importance in nature, bacterial community structure and its succession during biofilm development in the Antarctic marine environment have not been elucidated. In this study, the succession of bacterial community, particularly during the early stage of biofilm development, in the Antarctic marine environment was investigated by pyrosequencing of the 16S rRNA gene. Overall bacterial distribution in biofilms differed considerably from surrounding seawater. Relative abundance of Gammaproteobacteria and Bacteroidetes which accounted for 78.9-88.3% of bacterial community changed drastically during biofilm succession. Gammaproteobacteria became more abundant with proceeding succession (75.7% on day 4) and decreased to 46.1% on day 7. The relative abundance of Bacteroidetes showed opposite trend to Gammaproteobacteria, decreasing from the early days to the intermediate days and becoming more abundant in the later days. There were striking differences in the composition of major OTUs (${\geq}1%$) among samples during the early stages of biofilm formation. Gammaproteobacterial species increased until day 4, while members of Bacteroidetes, the most dominant group on day 1, decreased until day 4 and then increased again. Interestingly, Pseudoalteromonas prydzensis was predominant, accounting for up to 67.4% of the biofilm bacterial community and indicating its important roles in the biofilm development.

Bacterial Communities in the Initial Stage of Marine Biofilm Formation on Artificial Surfaces

Jin-Woo Lee,남지현,김양훈,이규호,이동훈 한국미생물학회 2008 The journal of microbiology Vol.46 No.2

Succession of bacterial communities during the first 36 h of biofilm formation in coastal water was investigated at 3~15 h intervals. Three kinds of surfaces (i.e., acryl, glass, and steel substratum) were submerged in situ at Sacheon harbor, Korea. Biofilms were harvested by scraping the surfaces, and the compositions of bacterial communities were analyzed by terminal restriction fragment length polymorphism (T-RFLP), and cloning and sequencing of 16S rRNA genes. While community structure based on T-RFLP analysis showed slight differences by substratum, dramatic changes were commonly observed for all substrata between 9 and 24 h. Identification of major populations by 16S rRNA gene sequences indicated that γ-Proteobacteria (Pseudomonas, Acinetobacter, Alteromonas, and uncultured γ-Proteobacteria) were predominant in the community during 0~9 h, while the ratio of α-Proteobacteria (Loktanella, Methylobacterium, Pelagibacter, and uncultured α-Proteobacteria) increased 2.6~4.8 folds during 24~36 h of the biofilm formation, emerging as the most predominant group. Previously, α-Proteobacteria were recognized as the pioneering organisms in marine biofilm formation. However, results of this study, which revealed the bacterial succession with finer temporal resolution, indicated some species of γ-Proteobacteria were more important as the pioneering population. Measures to control pioneering activities of these species can be useful in prevention of marine biofilm formation.

Soil development and bacterial community shifts along the chronosequence of the Midtre Lovénbreen glacier foreland in Svalbard

Kwon, Hye Young,Jung, Ji Young,Kim, Ok-Sun,Laffly, Dominique,Lim, Hyoun Soo,Lee, Yoo Kyung The Ecological Society of Korea 2015 Journal of Ecology and Environment Vol.38 No.4

Global warming has accelerated glacial retreat in the high Arctic. The exposed glacier foreland is an ideal place to study chronosequential changes in ecosystems. Although vegetation succession in the glacier forelands has been studied intensively, little is known about the microbial community structure in these environments. Therefore, this study focused on how glacial retreat influences the bacterial community structure and its relationship with soil properties. This study was conducted in the foreland of the Midtre Lovénbreen glacier in Svalbard (78.9°N). Seven soil samples of different ages were collected and analyzed for moisture content, pH, soil organic carbon and total nitrogen contents, and soil organic matter fractionation. In addition, the structure of the bacterial community was determined via pyrosequencing analysis of 16S rRNA genes. The physical and chemical properties of soil varied significantly along the distance from the glacier; with increasing distance, more amounts of clay and soil organic carbon contents were observed. In addition, Cyanobacteria, Firmicutes, and Actinobacteria were dominant in soil samples taken close to the glacier, whereas Acidobacteria were abundant further away from the glacier. Diversity indices indicated that the bacterial community changed from homogeneous to heterogeneous structure along the glacier chronosequence/distance from the glacier. Although the bacterial community structure differed on basis of the presence or absence of plants, the soil properties varied depending on soil age. These findings suggest that bacterial succession occurs over time in glacier forelands but on a timescale that is different from that of soil development.

Soil development and bacterial community shifts along the chronosequence of the Midtre Lovénbreen glacier foreland in Svalbard

권혜영,Ji Young Jung,김옥선,Dominique Laffly,임현수,이유경 한국생태학회 2015 Journal of Ecology and Environment Vol.38 No.4

Global warming has accelerated glacial retreat in the high Arctic. The exposed glacier foreland is an ideal place to study chronosequential changes in ecosystems. Although vegetation succession in the glacier forelands has been studied intensively, little is known about the microbial community structure in these environments. Therefore, this study focused on how glacial retreat influences the bacterial community structure and its relationship with soil properties. This study was conducted in the foreland of the Midtre Lovénbreen glacier in Svalbard (78.9°N). Seven soil samples of different ages were collected and analyzed for moisture content, pH, soil organic carbon and total nitrogen contents, and soil organic matter fractionation. In addition, the structure of the bacterial community was determined via pyrosequencing analysis of 16S rRNA genes. The physical and chemical properties of soil varied significantly along the distance from the glacier; with increasing distance, more amounts of clay and soil organic carbon contents were observed. In addition, Cyanobacteria, Firmicutes, and Actinobacteria were dominant in soil samples taken close to the glacier, whereas Acidobacteria were abundant further away from the glacier. Diversity indices indicated that the bacterial community changed from homogeneous to heterogeneous structure along the glacier chronosequence/distance from the glacier. Although the bacterial community structure differed on basis of the presence or absence of plants, the soil properties varied depending on soil age. These findings suggest that bacterial succession occurs over time in glacier forelands but on a timescale that is different from that of soil development.

영양상태가 다른 두 호수에서 섬유소 기질에 부착한 세균 군집의 천이

이영옥,홍선희,안태석 江原大學校 附設 環境硏究所 1998 環境硏究 Vol.15 No.-

To scrutinize the bacterial succession on detritus in aquatic ecosystem, morphology, numbers, and phylogenetic group of the bacterica were studied by Scanning Electron Microscopy, epiflourescence microscopy, and in situ hybridization respectively. Cellulose films as substrate were exposed to epiliminon of Lake Soyang and Moonchon from May, 1996 and collected weekly for analysis . In Lake Soyang, mesotrophic reservoir, the lesions as result of degradation apperaed after 5 week. while in Lake Moonchon , eutrophic reservoir, those appeared only after 1week. In Lake Soyang, the proportions of proteobacteria increased with the increase of exposing period. The proportions of proteobacteria were 48% after 4 weeks, 81% after 6 weeks and 100% after 8 weeks. In Moonchon Lake, Those were 57% after 2 weells, 100% after 6 weeks, and dracticallt dropped to 11% after 8 weeks. Among the phylogenetic group, α-group become dominant in both lakes.

Fluoroscopy-Guided Lumbar Drainage of Cerebrospinal Fluid for Patients in Whom a Blind Beside Approach Is Difficult

지충근,이근영,이준우,이영준,강흥식 대한영상의학회 2015 Korean Journal of Radiology Vol.16 No.4

To evaluate the rates of technical success, clinical success, and complications of fluoroscopy-guided lumbar cerebrospinal fluid drainage. This retrospective study was approved by the Institutional Review Board of our hospital, and informed consent was waived. Ninety-six procedures on 60 consecutive patients performed July 2008 to December 2013 were evaluated. The patients were referred for the fluoroscopy-guided procedure due to failed attempts at a bedside approach, a history of lumbar surgery, difficulty cooperating, or obesity. Fluoroscopy-guided lumbar drainage procedures were performed in the lateral decubitus position with a midline puncture of L3/4 in the interspinous space. The catheter tip was positioned at the T12/L1 level, and the catheter was visualized on contrast agent-aided fluoroscopy. A standard angiography system with a rotatable C-arm was used. The definitions of technical success, clinical success, and complications were defined prior to the study. The technical and clinical success rates were 99.0% (95/96) and 89.6% (86/96), respectively. The mean hospital stay for an external lumbar drain was 4.84 days. Nine cases of minor complications and eight major complications were observed, including seven cases of meningitis, and one retained catheter requiring surgical removal. Fluoroscopy-guided external lumbar drainage is a technically reliable procedure in difficult patients with failed attempts at a bedside procedure, history of lumbar surgery, difficulties in cooperation, or obesity.

Role of jeotgal, a Korean traditional fermented fish sauce, in microbial dynamics and metabolite profiles during kimchi fermentation

Jung, Min Young,Kim, Tae-Woon,Lee, Changsu,Kim, Joon Yong,Song, Hye Seon,Kim, Yeon Bee,Ahn, Seung Woo,Kim, Ju Seok,Roh, Seong Woon,Lee, Se Hee Elsevier 2018 Food chemistry Vol.265 No.-

<P><B>Abstract</B></P> <P>We investigated the effects of jeotgal (fermented fish sauce) on kimchi fermentation, with or without saeu-jeot and myeolchi-jeot. Bacterial community analysis showed that <I>Leuconostoc</I>, <I>Weissella</I>, <I>Lactobacillus</I>, and <I>Tetragenococcus</I> were the dominant genera; however, their succession depended on the presence of jeotgal. <I>Leuconostoc gasicomitatum</I> was the dominant species in kimchi without jeotgal, whereas <I>Weissella koreensis</I> and <I>Lactobacillus sakei</I> were the dominant species in kimchi with myeolchi-jeot and saeu-jeot, respectively. Metabolite analysis, using <SUP>1</SUP>H NMR, showed that the amounts of amino acids and gamma-aminobutyric acid (GABA) were higher in kimchi with jeotgal. Increases in acetate, lactate, and mannitol contents depended on fructose consumption and were more rapid in kimchi with jeotgal. Moreover, the consumption of various amino acids affected the increase in kimchi LAB. Thus, the role of jeotgal in kimchi fermentation was related to enhancement of taste, the amino acid source, and the increases in levels of functional metabolites.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Effects of jeotgal on kimchi lactic acid bacteria succession and metabolite changes. </LI> <LI> Jeotgal was facilitating the reduction of coliform originated from raw materials. </LI> <LI> Jeotgal affected the growth of LAB, which produce GABA, lactate, acetate, and mannitol. </LI> </UL> </P>

개량식 간장의 발효 초기 단계에서의 미생물 다양성 및 천이에 관한 연구

정호진(Ho Jin Jeong),하광수(Gwangsu Ha),이정미(Jungmi Lee),송예지(Yeji Song),정도연(Do-Youn Jeong),양희종(Hee-Jong Yang) 한국생명과학회 2023 생명과학회지 Vol.33 No.6