著者
Iulia Lupan Rahela Carpa Andreea Oltean Beatrice Simona Kelemen Octavian Popescu
出版者
日本微生物生態学会・日本土壌微生物学会
雑誌
Microbes and Environments (ISSN:13426311)
巻号頁・発行日
pp.ME17016, (Released:2017-08-05)
被引用文献数
30

The occurrence and spread of bacterial antibiotic resistance are subjects of great interest, and the role of wastewater treatment plants has been attracting particular interest. These stations are a reservoir of bacteria, have a large range of organic and inorganic substances, and the amount of bacteria released into the environment is very high. The main purpose of the present study was to assess the removal degree of bacteria with resistance to antibiotics and identify the contribution of a wastewater treatment plant to the microbiota of Someşul Mic river water in Cluj county. The resistance to sulfamethoxazole and tetracycline and some of their representative resistance genes: sul1, tet(O), and tet(W) were assessed in this study. The results obtained showed that bacteria resistant to sulphonamides were more abundant than those resistant to tetracycline. The concentration of bacteria with antibiotic resistance changed after the treatment, namely, bacteria resistant to sulfamethoxazole. The removal of all bacteria and antibiotic-resistant bacteria was 98–99% and the degree of removal of bacteria resistant to tetracycline was higher than the bacteria resistant to sulfamethoxazole compared to total bacteria. The wastewater treatment plant not only contributed to elevating ARG concentrations, it also enhanced the possibility of horizontal gene transfer (HGT) by increasing the abundance of the intI1 gene. Even though the treatment process reduced the concentration of bacteria by two orders of magnitude, the wastewater treatment plant in Cluj-Napoca contributed to an increase in antibiotic-resistant bacteria concentrations up to 10 km downstream of its discharge in Someşul Mic river.
著者
Bihe Kong Lei Chen Yasuhiro Kasahara Akihiro Sumida Kiyomi Ono Jan Wild Arata Nagatake Ryusuke Hatano Toshihiko Hara
出版者
日本微生物生態学会 / 日本土壌微生物学会 / Taiwan Society of Microbial Ecology / 植物微生物研究会
雑誌
Microbes and Environments (ISSN:13426311)
巻号頁・発行日
pp.ME16154, (Released:2017-04-28)
被引用文献数
5

In order to understand the relationships between understory bamboo and soil properties, we compared microbial community structures in the soil of a Betula ermanii boreal forest with Sasa kurilensis present and removed using high-throughput DNA sequencing. The presence of understory S. kurilensis strongly affected soil properties, including total carbon, total nitrogen, nitrate, and the C:N ratio as well as relative soil moisture. Marked differences were also noted in fungal and bacterial communities between plots. The relative abundance of the fungal phylum Ascomycota was 13.9% in the Sasa-intact plot and only 0.54% in the Sasa-removed plot. Among the Ascomycota fungi identified, the most prevalent were members of the family Pezizaceae. We found that the abundance of Pezizaceae, known to act as mycorrhizal fungi, was related to the amount of total carbon in the Sasa-intact plot. The relative abundance of Proteobacteria was significantly higher, whereas those of Planctomycetes and Actinobacteria were lower in the Sasa-intact plot than in the Sasa-removed plot. Furthermore, the results obtained suggest that some species of the phylum Planctomycetes are more likely to occur in the presence of S. kurilensis. Collectively, these results indicate that the presence of S. kurilensis affects microbial communities and soil properties in a B. ermanii boreal forest.
著者
Yosuke Tashiro Hiroaki Eida Satoshi Ishii Hiroyuki Futamata Satoshi Okabe
出版者
日本微生物生態学会 / 日本土壌微生物学会 / Taiwan Society of Microbial Ecology / 植物微生物研究会
雑誌
Microbes and Environments (ISSN:13426311)
巻号頁・発行日
vol.32, no.1, pp.40-46, 2017 (Released:2017-03-31)
参考文献数
44
被引用文献数
19

A conjugative F plasmid induces mature biofilm formation by Escherichia coli by promoting F-pili-mediated cell-cell interactions and increasing the expression of biofilm-related genes. We herein demonstrated another function for the F plasmid in E. coli biofilms; it contributes to the emergence of genetic and phenotypic variations by spontaneous mutations. Small colony variants (SCVs) were more frequently generated in a continuous flow-cell biofilm than in the planktonic state of E. coli harboring the F plasmid. E. coli SCVs represented typical phenotypic changes such as slower growth, less biofilm formation, and greater resistance to aminoglycoside antibiotics than the parent strain. Genomic and complementation analyses indicated that the small colony phenotype was caused by the insertion of Tn1000, which was originally localized in the F plasmid, into the hemB gene. Furthermore, the Tn1000 insertion was removed from hemB in the revertant, which showed a normal colony phenotype. This study revealed that the F plasmid has the potential to increase genetic variations not only by horizontal gene transfer via F pili, but also by site-specific recombination within a single cell.
著者
Camilla Kristoffersen Rasmus B. Jensen Ekaterina Avershina Dag Austbø Anne-Helene Tauson Knut Rudi
出版者
日本微生物生態学会 / 日本土壌微生物学会 / Taiwan Society of Microbial Ecology / 植物微生物研究会
雑誌
Microbes and Environments (ISSN:13426311)
巻号頁・発行日
pp.ME16061, (Released:2016-10-21)
被引用文献数
14

Knowledge on dynamic interactions in microbiota is pivotal for understanding the role of bacteria in the gut. We herein present comprehensive dynamic models of the horse cecal microbiota, which include short-chained fatty acids, carbohydrate metabolic networks, and taxonomy. Dynamic models were derived from time-series data in a crossover experiment in which four cecum-cannulated horses were fed a starch-rich diet of hay supplemented with barley (starch intake 2 g kg–1 body weight per day) and a fiber-rich diet of only hay. Cecal contents were sampled via the cannula each h for 24 h for both diets. We observed marked differences in the microbial dynamic interaction patterns for Fibrobacter succinogenes, Lachnospiraceae, Streptococcus, Treponema, Anaerostipes, and Anaerovibrio between the two diet groups. Fluctuations and microbiota interactions were the most pronounced for the starch rich diet, with Streptococcus spp. and Anaerovibrio spp. showing the largest fluctuations. Shotgun metagenome sequencing revealed that diet differences may be explained by modular switches in metabolic cross-feeding between microbial consortia in which fermentation is linked to sugar alcohols and amino sugars for the starch-rich diet and monosaccharides for the fiber-rich diet. In conclusion, diet may not only affect the composition of the cecal microbiota, but also dynamic interactions and metabolic cross-feeding.
著者
Wataru Suda Asami Nagasaki Masahiro Shishido
出版者
日本微生物生態学会 / 日本土壌微生物学会 / Taiwan Society of Microbial Ecology / 植物微生物研究会
雑誌
Microbes and Environments (ISSN:13426311)
巻号頁・発行日
vol.24, no.3, pp.217-223, 2009 (Released:2009-09-04)
参考文献数
40
被引用文献数
20 45

To investigate changes in bacterial communities associated with a fungal foliar disease, epiphytic bacteria from powdery mildew-infected and uninfected leaves of cucumber and Japanese spindle were analyzed using both culture-dependent and -independent methods. Dilution plate counting suggested that powdery mildew-infected leaves likely accommodated larger populations of phyllosphere bacteria than uninfected leaves. Community-level physiological profiles (CLPP) also indicated that functional diversity, richness, and evenness of bacterial communities were significantly greater in the phyllosphere of powdery mildew-infected leaves. Genotype diversity and richness based on band patterns of denaturing gradient gel electrophoresis (DGGE) of the phyllosphere bacterial community were greater for leaves infected by powdery mildew. A principle component analysis of CLPP and DGGE patterns revealed a clear difference between infected and uninfected leaves of both plant species. These results suggest that powdery mildew-infection results in larger bacterial populations, and greater diversity and richness, and also changes the structure of the phyllosphere bacterial community. Furthermore, DNA sequences of the DGGE bands that showed greater intensity in the infected than uninfected leaves, differed between cucumber and Japanese spindle. This suggests that specific bacteria are associated with the plant species accompanying this fungal infection.
著者
Chandan Lall K. Vinod Kumar R. Vimal Raj K. Vedhagiri P. Vijayachari
出版者
日本微生物生態学会 / 日本土壌微生物学会 / Taiwan Society of Microbial Ecology / 植物微生物研究会
雑誌
Microbes and Environments (ISSN:13426311)
巻号頁・発行日
pp.ME15149, (Released:2016-03-03)
被引用文献数
1 17

Leptospirosis is an emerging disease around the globe. South Andaman Island is an endemic region for leptospirosis. We herein compared the prevalence of leptospires in urban and rural areas of South Andaman Island. The PCR detection and isolation of Leptospira revealed that pathogenic leptospires were prevalent in sewage water and household drainage water in urban areas and in paddy fields, vegetable field water, and stream water in rural areas. These results demonstrate that intermediates are ubiquitously present in the environment and may be responsible for asymptomatic infections, and also provide an insight into disease ecology.
著者
Rebeca Padilla-Reynaud Anne-Marie Simao-Beaunoir Sylvain Lerat Mark A. Bernards Carole Beaulieu
出版者
Japanese Society of Microbial Ecology / Japanese Society of Soil Microbiology / Taiwan Society of Microbial Ecology / Japanese Society of Plant Microbe Interactions / Japanese Society for Extremophiles
雑誌
Microbes and Environments (ISSN:13426311)
巻号頁・発行日
pp.ME15034, (Released:2015-09-01)
被引用文献数
11 23

Suberin, a major constituent of the potato periderm, is known to promote the production of thaxtomins, the key virulence factors of the common scab-causing agent Streptomyces scabiei. In the present study, we speculated that suberin affected the production of glycosyl hydrolases, such as cellulases, by S. scabiei, and demonstrated that suberin promoted glycosyl hydrolase activity when added to cellulose-, xylan-, or lichenin-containing media. Furthermore, secretome analyses revealed that the addition of suberin to a cellulose-containing medium increased the production of glycosyl hydrolases. For example, the production of 13 out of the 14 cellulases produced by S. scabiei in cellulose-containing medium was stimulated by the presence of suberin. In most cases, the transcription of the corresponding cellulase-encoding genes was also markedly increased when the bacterium was grown in the presence of suberin and cellulose. The level of a subtilase-like protease inhibitor was markedly decreased by the presence of suberin. We proposed a model for the onset of S. scabiei virulence mechanisms by both cellulose and suberin, the main degradation product of cellulose that acts as an inducer of thaxtomin biosynthetic genes, and suberin promoting the biosynthesis of secondary metabolites including thaxtomins.
著者
Hao Zheng Carsten Dietrich Claire L. Thompson Katja Meuser Andreas Brune
出版者
Japanese Society of Microbial Ecology / Japanese Society of Soil Microbiology / Taiwan Society of Microbial Ecology / Japanese Society of Plant Microbe Interactions / Japanese Society for Extremophiles
雑誌
Microbes and Environments (ISSN:13426311)
巻号頁・発行日
pp.ME14169, (Released:2015-02-26)
被引用文献数
16 29

The gut microbiota of many phylogenetically lower termites is dominated by the cellulolytic flagellates of the genus Trichonympha, which are consistently associated with bacterial symbionts. In the case of Endomicrobia, an unusual lineage of endosymbionts of the Elusimicrobia phylum that is also present in other gut flagellates, previous studies have documented strict host specificity, leading to the cospeciation of “Candidatus Endomicrobium trichonymphae” with their respective flagellate hosts. However, it currently remains unclear whether one Trichonympha species is capable of harboring more than one Endomicrobia phylotype. In the present study, we selected single Trichonympha cells from the guts of Zootermopsis nevadensis and Reticulitermes santonensis and characterized their Endomicrobia populations based on internal transcribed spacer (ITS) region sequences. We found that each host cell harbored a homogeneous population of symbionts that were specific to their respective host species, but phylogenetically distinct between each host lineage, corroborating cospeciation being caused by vertical inheritance. The experimental design of the present study also allowed for the identification of an unexpectedly large amount of tag-switching between samples, which indicated that any high-resolution analysis of microbial community structures using the pyrosequencing technique has to be interpreted with great caution.
著者
Nobuyasu Yamaguchi Michael Roberts Sarah Castro Cherie Oubre Koichi Makimura Natalie Leys Elisabeth Grohmann Takashi Sugita Tomoaki Ichijo Masao Nasu
出版者
日本微生物生態学会 / 日本土壌微生物学会 / Taiwan Society of Microbial Ecology / 植物微生物研究会
雑誌
Microbes and Environments (ISSN:13426311)
巻号頁・発行日
pp.ME14031, (Released:2014-08-12)
被引用文献数
8 81 1

Previous space research conducted during short-term flight experiments and long-term environmental monitoring on board orbiting space stations suggests that the relationship between humans and microbes is altered in the crewed habitat in space. Both human physiology and microbial communities adapt to spaceflight. Microbial monitoring is critical to crew safety in long-duration space habitation and the sustained operation of life support systems on space transit vehicles, space stations, and surface habitats. To address this critical need, space agencies including NASA(National Aeronautics and Space Administration), ESA (European Space Agency), and JAXA (Japan Aerospace Exploration Agency) are working together to develop and implement specific measures to monitor, control, and counteract biological contamination in closed-environment systems. In this review, the current status of microbial monitoring conducted in the International Space Station (ISS) as well as the results of recent microbial spaceflight experiments have been summarized and future perspectives are discussed.
著者
Kasthuri Venkateswaran Myron T. La Duc Gerda Horneck
出版者
日本微生物生態学会 / 日本土壌微生物学会 / Taiwan Society of Microbial Ecology / 植物微生物研究会
雑誌
Microbes and Environments (ISSN:13426311)
巻号頁・発行日
pp.ME14032, (Released:2014-08-12)
被引用文献数
6 23 1

The National Research Council (NRC) has recently recognized the International Space Station (ISS) as uniquely suitable for furthering the study of microbial species in closed habitats. Answering the NRC’s call for the study, in particular, of uncommon microbial species in the ISS, and/or of those that have significantly increased or decreased in number, space microbiologists have begun capitalizing on the maturity, speed, and cost-effectiveness of molecular/genomic microbiological technologies to elucidate changes in microbial populations in the ISS and other closed habitats. Since investigators can only collect samples infrequently from the ISS itself due to logistical reasons, Earth analogs, such as spacecraft-assembly clean rooms, are used and extensively characterized for the presence of microbes.Microbiologists identify the predominant, problematic, and extremophilic microbial species in these closed habitats and use the ISS as a testbed to study their resistance to extreme extraterrestrial environmental conditions. Investigators monitor the microbes exposed to the real space conditions in order to track their genomic changes in response to the selective pressures present in outer space (external to the ISS) and the spaceflight (in the interior of the ISS). In this review, we discussed the presence of microbes in space research-related closed habitats and the resistance of some microbial species to the extreme environmental conditions of space.
著者
Takashi Narihiro Aya Suzuki Kazuaki Yoshimune Tomoyuki Hori Tamotsu Hoshino Isao Yumoto Atsushi Yokota Nobutada Kimura Yoichi Kamagata
出版者
日本微生物生態学会 / 日本土壌微生物学会 / Taiwan Society of Microbial Ecology / 植物微生物研究会
雑誌
Microbes and Environments (ISSN:13426311)
巻号頁・発行日
vol.29, no.2, pp.154-161, 2014 (Released:2014-07-19)
参考文献数
64
被引用文献数
4 12

Metagenomic screening and conventional cultivation have been used to exploit microbial lipolytic enzymes in nature. We used an indigenous forest soil (NS) and oil-fed enriched soil (OS) as microbial and genetic resources. Thirty-four strains (17 each) of lipolytic bacteria were isolated from the NS and OS microcosms. These isolates were classified into the (sub)phyla Betaproteobacteria, Gammaproteobacteria, Firmicutes, and Actinobacteria, all of which are known to be the main microbial resources of commercially available lipolytic enzymes. Seven and 39 lipolytic enzymes were successfully retrieved from the metagenomic libraries of the NS and OS microcosms, respectively. The screening efficiency (a ratio of positive lipolytic clones to the total number of environmental clones) was markedly higher in the OS microcosm than in the NS microcosm. Moreover, metagenomic clones encoding the lipolytic enzymes associated with Alphaproteobacteria, Deltaproteobacteria, Acidobacteria, Armatimonadetes, and Planctomycetes and hitherto-uncultivated microbes were recovered from these libraries. The results of the present study indicate that functional metagenomics can be effectively used to capture as yet undiscovered lipolytic enzymes that have eluded the cultivation-based method, and these combined approaches may be able to provide an overview of lipolytic organisms potentially present in nature.
著者
松浦 克美
出版者
日本微生物生態学会 / 日本土壌微生物学会 / Taiwan Society of Microbial Ecology / 植物微生物研究会
雑誌
Microbes and Environments (ISSN:13426311)
巻号頁・発行日
vol.13, no.4, pp.269-275, 1998-12-31 (Released:2009-10-05)
参考文献数
23
被引用文献数
1 1

Green filamentous bacteria (Chloroflexus) and cyanobacteria are commonly observed in bacterial mats of hot springs with the temperature range betwen 45 and 70°C and pH range between 6.5 and 9.0. Sulfide concentration is another factor which largely affects the distribution of thermophilic photosynthetic bacteria. Chloroflexus spp. are thought to maintain many characteristics of the oldest photosynthetic bacteria. Photosynthetic bacterial mats in hot springs are important for the studies on early stages of the evolution of photosynthesis.
著者
Yuki Sato-Takabe Koji Hamasaki Koji Suzuki
出版者
日本微生物生態学会 / 日本土壌微生物学会 / Taiwan Society of Microbial Ecology / 植物微生物研究会
雑誌
Microbes and Environments (ISSN:13426311)
巻号頁・発行日
vol.29, no.1, pp.100-103, 2014 (Released:2014-04-02)
参考文献数
17
被引用文献数
4 12

This paper describes the photosynthetic response of a Roseobacter strain of marine aerobic anoxygenic phototrophic bacteria to an organic substrate limitation. In batch cultures, higher values of the spheroidenone/bacteriochlorophyll a ratio were observed under substrate-deficient conditions. Interestingly, the maximum photochemical quantum efficiencies of the photosystem under substrate-deficient conditions using blue or green excitation were significantly higher than those under substrate-replete conditions. These results indicate that spheroidenone, which can absorb green light, may play an important role in their photosynthesis as a light-harvesting antenna pigment, and the photosynthetic competence of the Roseobacter strain can increase in an organic substrate-deficient environment.
著者
Dong Han Choi Jae Hoon noH Jung-Hyun Lee
出版者
日本微生物生態学会 / 日本土壌微生物学会 / Taiwan Society of Microbial Ecology / 植物微生物研究会
雑誌
Microbes and Environments (ISSN:13426311)
巻号頁・発行日
vol.29, no.1, pp.17-22, 2014 (Released:2014-04-02)
参考文献数
36
被引用文献数
2 10

Synechococcus are distributed throughout the world’s oceans and are composed of diverse genetic lineages. However, as they are much less abundant than Prochlorococcus in oligotrophic open oceans, their in-depth genetic diversity cannot be investigated using commonly used primers targeting both Prochlorococcus and Synechococcus. Thus, in this study, we designed a primer specific to the 16S–23S rRNA internal transcribed spacer (ITS) of the Synechococcus subcluster 5.1. Using the primer, we could selectively amplify Synechococcus sequences in oligotrophic seawater samples. Further, we showed that a barcoded amplicon pyrosequencing method could be applicable to investigate Synechococcus diversity using sequences retrieved in GenBank and obtained from environmental samples. Allowing sequence analyses of a large number of samples, this high-throughput method would be useful to study global biodiversity and biogeographic patterns of Synechococcus in marine environments.
著者
Kazuo Isobe Nobuhito Ohte
出版者
日本微生物生態学会 / 日本土壌微生物学会 / Taiwan Society of Microbial Ecology / 植物微生物研究会
雑誌
Microbes and Environments (ISSN:13426311)
巻号頁・発行日
vol.29, no.1, pp.4-16, 2014 (Released:2014-04-02)
参考文献数
143
被引用文献数
17 105

Nitrogen (N) cycles have been directly linked to the functional stability of ecosystems because N is an essential element for life. Furthermore, the supply of N to organisms regulates primary productivity in many natural ecosystems. Microbial communities have been shown to significantly contribute to N cycles because many N-cycling processes are microbially mediated. Only particular groups of microbes were implicated in N-cycling processes, such as nitrogen fixation, nitrification, and denitrification, until a few decades ago. However, recent advances in high-throughput sequencing technologies and sophisticated isolation techniques have enabled microbiologists to discover that N-cycling microbes are unexpectedly diverse in their functions and phylogenies. Therefore, elucidating the link between biogeochemical N-cycling processes and microbial community dynamics can provide a more mechanistic understanding of N cycles than the direct observation of N dynamics. In this review, we summarized recent findings that characterized the microbes governing novel N-cycling processes. We also discussed the ecological role of N-cycling microbial community dynamics, which is essential for advancing our understanding of the functional stability of ecosystems.
著者
Francesc Codony Mariana Fittipaldi Esther López Jordi Morató Gemma Agustí
出版者
日本微生物生態学会 / 日本土壌微生物学会 / Taiwan Society of Microbial Ecology / 植物微生物研究会
雑誌
Microbes and Environments (ISSN:13426311)
巻号頁・発行日
vol.27, no.4, pp.529-532, 2012 (Released:2012-12-07)
参考文献数
20
被引用文献数
9 20

Waddlia chondrophila is an emerging pathogen considered as a potential agent of abortion in humans and bovines, and is related with human respiratory disease. Despite these findings, the infection source and transmission pathways have not been identified. The evidence of growth into amoeba suggests water as a possible environmental source. The presence of Waddlia chondrophila was determined in drinking and well water samples (n=70) by quantitative PCR (Q-PCR). Positive results were observed in 10 (25%) of the 40 well samples analyzed; therefore, well water could be a potential reservoir and possible infection source of Waddlia chondrophila in animals and humans.
著者
Dong Han Choi Jae Hoon Noh Jung-Hyun Lee
出版者
日本微生物生態学会 / 日本土壌微生物学会 / Taiwan Society of Microbial Ecology / 植物微生物研究会
雑誌
Microbes and Environments (ISSN:13426311)
巻号頁・発行日
pp.ME13063, (Released:2013-12-28)
被引用文献数
2 10

Synechococcus are distributed throughout the world’s oceans and are composed of diverse genetic lineages. However, as they are much less abundant than Prochlorococcus in oligotrophic open oceans, their in-depth genetic diversity cannot be investigated using commonly used primers targeting both Prochlorococcus and Synechococcus. Thus, in this study, we designed a primer specific to the 16S-23S rRNA internal transcribed spacer (ITS) of the Synechococcus subcluster 5.1. Using the primer, we could selectively amplify Synechococcus sequences in oligotrophic seawater samples. Further, we showed that a barcoded amplicon pyrosequencing method could be applicable to investigate Synechococcus diversity using sequences retrieved in GenBank and obtained from environmental samples. Allowing sequence analyses of a large number of samples, this high-throughput method would be useful to study global biodiversity and biogeographic patterns of Synechococcus in marine environments.
著者
Akira Kawaguchi
出版者
日本微生物生態学会 / 日本土壌微生物学会 / Taiwan Society of Microbial Ecology / 植物微生物研究会
雑誌
Microbes and Environments (ISSN:13426311)
巻号頁・発行日
vol.28, no.3, pp.306-311, 2013 (Released:2013-09-21)
参考文献数
27
被引用文献数
7 29

A nonpathogenic strain of Rhizobium vitis ARK-1 was tested as a biological control agent for grapevine crown gall. When grapevine roots were soaked in a cell suspension of strain ARK-1 before planting in the field, the number of plants with tumors was reduced. The results from seven field trials from 2009 to 2012 were combined in a meta-analysis. The integrated relative risk after treatment with ARK-1 was 0.15 (95% confidence interval: 0.07–0.29, P<0.001), indicating that the disease incidence was significantly reduced by ARK-1. In addition, the results from four field trials from 2007 to 2009 using R. vitis VAR03-1, a previously reported biological control agent for grapevine crown gall, were combined in a meta-analysis. The integrated relative risk after treatment with VAR03-1 was 0.24 (95% confidence interval: 0.11–0.53, P<0.001), indicating the superiority of ARK-1 in inhibiting grapevine crown gall over VAR03-1 under field conditions. ARK-1 did not cause necrosis on grapevine shoot explants. ARK-1 established populations on roots of grapevine tree rootstock and persisted inside roots for two years.
著者
Satoshi Kawaichi Norihiro Ito Takashi Yoshida Yoshihiko Sako
出版者
日本微生物生態学会 / 日本土壌微生物学会 / Taiwan Society of Microbial Ecology / 植物微生物研究会
雑誌
Microbes and Environments (ISSN:13426311)
巻号頁・発行日
pp.ME13048, (Released:2013-11-21)
被引用文献数
3 9

Physicochemical characteristics and archaeal and bacterial community structures in an iron-rich coastal hydrothermal field, where the temperature of the most active hot spot reaches above 100ーC, were investigated to obtain fundamental information on microbes inhabiting a coastal hydrothermal field. The environmental settings of the coastal hydrothermal field were similar in some degree to those of deep-sea hydrothermal environments because of its emission of H2, CO2, and sulfide from the bottom of the hot spot. The results of clone analyses based on the 16S rRNA gene led us to speculate the presence of a chemo-synthetic microbial ecosystem, where chemolithoautotrophic thermophiles, primarily the bacterial order Aquificales, function as primary producers using H2 or sulfur compounds as their energy source and CO2 as their carbon source, and the organic compounds synthesized by them support the growth of chemoheterotrophic thermophiles, such as members of the order Thermales and the family Desulfurococcaceae. In addition, the dominance of members of the bacterial genus Herbaspirillum in the high temperature bottom layer led us to speculate the temporal formation of mesophilic zones where they can also function as primary producing or nitrogen-fixing bacteria.