2016 年我們參加了 8 月在金山舉辦的第 21 屆細菌學研討會。
第 21 屆細菌學研討會
Characterization of caffeine-tolerant and caffeine-degrading bacteria from various soils
You-Jia Zhang (張祐嘉)1,2, Ying-Ju Chiu (邱映儒)1,2, Miao-Zhen Chen (陳妙禎)1,2, Zi-Yan Pan (潘姿嫣)1,2, Zi-Zhen Pan (潘姿甄)1,2, Chun-Yao Chen (陳俊堯)2
Hualien Tzu Chi Senior High School (花蓮慈濟大學附屬高中)1; Department Of Life Science, Tzu Chi University (慈濟大學生命科學系)2
Global consumption of coffee and other caffeine-containing drinks are immense. The resulting caffeine-containing wastes such as coffee ground, when released to the environment, may have impact on microbial community. In this study we examined the impact of caffeine on culturable soil bacteria, collected from 5 different locations. We tested the inhibitory effect on soil bacteria using media containing varying concentration of caffeine. Number of culturable bacteria was apparently affected at 10 mM, and a major reduction occurred at 30 mM, and no viable colony was seen at 50 mM. We picked 39 isolates from media containing 10 mM caffeine as representative caffeine-tolerant isolates. Among them, 9 (23%) were have no or very poor growth at 30 mM caffeine. This suggests that direct disposal of coffee ground could potentially affect many soil bacteria. Twelve (31%) isolates were able to grow on medium with caffeine as the only carbon source. These presumably caffeine-degrading bacteria were identified as Pseudomonas species using 16S rDNA sequencing. The presence of caffine in medium suppressed the red pigment production in one caffeine-tolerant Serratia isolate, suggesting caffeine could interfere quorum-sensing mechanism in soil bacteria.
Key words: caffeine-degrading bacteria, soil bacteria
You-Jia Zhang (張祐嘉)1,2, Ying-Ju Chiu (邱映儒)1,2, Miao-Zhen Chen (陳妙禎)1,2, Zi-Yan Pan (潘姿嫣)1,2, Zi-Zhen Pan (潘姿甄)1,2, Chun-Yao Chen (陳俊堯)2
Hualien Tzu Chi Senior High School (花蓮慈濟大學附屬高中)1; Department Of Life Science, Tzu Chi University (慈濟大學生命科學系)2
Global consumption of coffee and other caffeine-containing drinks are immense. The resulting caffeine-containing wastes such as coffee ground, when released to the environment, may have impact on microbial community. In this study we examined the impact of caffeine on culturable soil bacteria, collected from 5 different locations. We tested the inhibitory effect on soil bacteria using media containing varying concentration of caffeine. Number of culturable bacteria was apparently affected at 10 mM, and a major reduction occurred at 30 mM, and no viable colony was seen at 50 mM. We picked 39 isolates from media containing 10 mM caffeine as representative caffeine-tolerant isolates. Among them, 9 (23%) were have no or very poor growth at 30 mM caffeine. This suggests that direct disposal of coffee ground could potentially affect many soil bacteria. Twelve (31%) isolates were able to grow on medium with caffeine as the only carbon source. These presumably caffeine-degrading bacteria were identified as Pseudomonas species using 16S rDNA sequencing. The presence of caffine in medium suppressed the red pigment production in one caffeine-tolerant Serratia isolate, suggesting caffeine could interfere quorum-sensing mechanism in soil bacteria.
Key words: caffeine-degrading bacteria, soil bacteria
Characterization of chitin-degrading bacteria isolated from a freshwater microbial mat
Yu-Chi Yang (楊又齊), Chun-Yao Chen (陳俊堯)
Department of Life Science, Tzu-Chi University
Microbial mat is a highly diverse microbial community and contains microbes with various metabolic capability. Finding the role of each member plays in this community may help us to understand the underlying principles of how the community is formed and maintained. Using massive parallel sequencing technique, we detected the presence of chitin-degrading taxa in a freshwater microbial mat. We isolated heterotrophic bacteria and tested them for chitin-degrading and chitosan-degrading capabilities. About half (47%) of the isolates could degrade either polymers, with 6 isolates (35%) are chitin-degrading and 6 are chitosan-degrading, and 4 isolates (23%) have both capabilities. The 16S rDNA sequencing results indicate that most of our isolates were Stenotrophomonas maltophilia, with 99% sequence identify. No fungal cells were isolated from the mat, therefore we suspect that these chitin-degrading bacteria may help to prevent fungal invasion.
Key words: chitin-degrading, freshwater microbial mat
Yu-Chi Yang (楊又齊), Chun-Yao Chen (陳俊堯)
Department of Life Science, Tzu-Chi University
Microbial mat is a highly diverse microbial community and contains microbes with various metabolic capability. Finding the role of each member plays in this community may help us to understand the underlying principles of how the community is formed and maintained. Using massive parallel sequencing technique, we detected the presence of chitin-degrading taxa in a freshwater microbial mat. We isolated heterotrophic bacteria and tested them for chitin-degrading and chitosan-degrading capabilities. About half (47%) of the isolates could degrade either polymers, with 6 isolates (35%) are chitin-degrading and 6 are chitosan-degrading, and 4 isolates (23%) have both capabilities. The 16S rDNA sequencing results indicate that most of our isolates were Stenotrophomonas maltophilia, with 99% sequence identify. No fungal cells were isolated from the mat, therefore we suspect that these chitin-degrading bacteria may help to prevent fungal invasion.
Key words: chitin-degrading, freshwater microbial mat
Duttaphrynus melanostictus tadpole gut microbiota: origins and community dynamics through developmental stages
Ya-Ting Hsu (許雅婷)1,2, Chun-Yao Chen (陳俊堯)2, Han-Chen Ho (何翰蓁)1
Department of Anatomy1, Department of Life Science2, Tzu-Chi University
Gut bacteria play important roles in animal health. Animals can acquire gut microbes from either the environment or their parents. Amphibian tadpoles generally hatched after their parents left the spawning sites, therefore more likely to acquire microbes from the environment. Here, we used Duttaphrynus melanostictus, a common species of toad, to investigate sources of amphibian gut microbes. We traced microbiota of parents and offsprings at various developmental stage, as well as samples from their environments (water and soil), using 16S rDNA Illumina sequencing. Eggs, tadpoles, parents and environments differ markedly in microbial composition. Tadpole gut microbiota shared certain OTUs with environments yet another with that of parental gut, suggesting that both sources are important in shaping tadpole gut communities. Eggs and environments have similar microbiota, which were dominated by Proteobacteria (87.7% and 42.5%, respectively) and Bacteroidetes (11.4%, 30.6%). Both adults and tadpoles contains more Firmicutes (42.2% and 13.4%) and Bacteroidetes (23.7% and 44.4%). When microbiota from different clutches were compared, developmental stages was a more important factor in determining microbial composition. Bacterial communities of tadpoles were significantly altered during metamorphosis, with much higher relative abundance of Fusobacteria. These results indicated that metamorphosis may be a bottleneck that can influencing microbial diversity.
Key words: amphibian, tadpole, gut microbiota
Ya-Ting Hsu (許雅婷)1,2, Chun-Yao Chen (陳俊堯)2, Han-Chen Ho (何翰蓁)1
Department of Anatomy1, Department of Life Science2, Tzu-Chi University
Gut bacteria play important roles in animal health. Animals can acquire gut microbes from either the environment or their parents. Amphibian tadpoles generally hatched after their parents left the spawning sites, therefore more likely to acquire microbes from the environment. Here, we used Duttaphrynus melanostictus, a common species of toad, to investigate sources of amphibian gut microbes. We traced microbiota of parents and offsprings at various developmental stage, as well as samples from their environments (water and soil), using 16S rDNA Illumina sequencing. Eggs, tadpoles, parents and environments differ markedly in microbial composition. Tadpole gut microbiota shared certain OTUs with environments yet another with that of parental gut, suggesting that both sources are important in shaping tadpole gut communities. Eggs and environments have similar microbiota, which were dominated by Proteobacteria (87.7% and 42.5%, respectively) and Bacteroidetes (11.4%, 30.6%). Both adults and tadpoles contains more Firmicutes (42.2% and 13.4%) and Bacteroidetes (23.7% and 44.4%). When microbiota from different clutches were compared, developmental stages was a more important factor in determining microbial composition. Bacterial communities of tadpoles were significantly altered during metamorphosis, with much higher relative abundance of Fusobacteria. These results indicated that metamorphosis may be a bottleneck that can influencing microbial diversity.
Key words: amphibian, tadpole, gut microbiota
Microbial diversity associated with several zoanthid species in intertidal zone
Xiao-Jun Yu (徐筱珺), Mei-Shiou Wan (萬美秀), Nai-Hsuan Yang (楊乃璇), Chun-Yao Chen (陳俊堯)
Department of Life Science, Tzu-Chi University
Coral reefs support the lives of various marine creatures and is a hotspot for biodiversity. Cnidarians dominate the coral reef communities. Extensive research effort has been put on coral biology, however anemones are much less studied. In this project we aim to examine the bacterial diversity associated with zoanthids and solitary anemones in intertidal zones in Hualien. In the past year we established an inventory of anemone-associated bacterial communities using Illumina-based massive parallel sequencing. In general, the bacterial community associated with zoanthids was dominated by Proteobacteria, Bacteroidetes, Cyanobacteria and Spirochetes. The most dominant genera include Vibrio, Borellia and Ruegeria. Zoanthid-associated microbiota are very different from that of seawater and that of solitary anemones. There is no apparent host specificity in bacterial composition.
Key words: anemones, microbiota
Xiao-Jun Yu (徐筱珺), Mei-Shiou Wan (萬美秀), Nai-Hsuan Yang (楊乃璇), Chun-Yao Chen (陳俊堯)
Department of Life Science, Tzu-Chi University
Coral reefs support the lives of various marine creatures and is a hotspot for biodiversity. Cnidarians dominate the coral reef communities. Extensive research effort has been put on coral biology, however anemones are much less studied. In this project we aim to examine the bacterial diversity associated with zoanthids and solitary anemones in intertidal zones in Hualien. In the past year we established an inventory of anemone-associated bacterial communities using Illumina-based massive parallel sequencing. In general, the bacterial community associated with zoanthids was dominated by Proteobacteria, Bacteroidetes, Cyanobacteria and Spirochetes. The most dominant genera include Vibrio, Borellia and Ruegeria. Zoanthid-associated microbiota are very different from that of seawater and that of solitary anemones. There is no apparent host specificity in bacterial composition.
Key words: anemones, microbiota
Impact of commonly used herbicides on soil diazotrophic bacteria
Cheng-Lin Wu (吳承霖)1,2, Ming-Xuan Li (李明軒)1,2, Sheng-Jun Peng (彭勝軍)1,2, Sheng-Kang Peng (彭勝康)1,2, Chun-Yao Chen (陳俊堯)2
Hualien Szu Wei Senior High School (花蓮四維高級中學)1; Department Of Life Science, Tzu Chi University (慈濟大學生命科學系)2
Agriculture operation physically and chemically changes the soil. The application of anthropogenic chemicals such as herbicides have a direct impact on herbal community, but whether they will influence the microbial community is still relatively unknown. In this study we examine the influence of herbicides atrazine, paraquat and phenylurea on diazotrophic bacteria. A total of 71 diazotrophic bacteria were isolated from soils of reforested area, organic fertilized field and chemically fertilized field, including Streptomyces, Burkholderia, Rhizobium and Micrococcus. We found that paraquat and phenylurea inhibited almost all diazotrophs we tested, and no isolate showed capability of utilizing them as nutrients. However, atrazine was less inhibitory and only less than half of tested isolates were inhibited. Besides, some isolates grew better in the presence of atrazine, suggested that they might be capable of using atrazine as nutrient. Streptomyces isolated from both organic farm and reforested area were highly susceptible to all 3 herbicides. We conclude that diazotrophic bacteria are likely to be eliminated when exposed to herbicide application in conventional agriculture practice and should be taken into consideration.
Key words: herbicides, soil diazotrophic bacteria
Cheng-Lin Wu (吳承霖)1,2, Ming-Xuan Li (李明軒)1,2, Sheng-Jun Peng (彭勝軍)1,2, Sheng-Kang Peng (彭勝康)1,2, Chun-Yao Chen (陳俊堯)2
Hualien Szu Wei Senior High School (花蓮四維高級中學)1; Department Of Life Science, Tzu Chi University (慈濟大學生命科學系)2
Agriculture operation physically and chemically changes the soil. The application of anthropogenic chemicals such as herbicides have a direct impact on herbal community, but whether they will influence the microbial community is still relatively unknown. In this study we examine the influence of herbicides atrazine, paraquat and phenylurea on diazotrophic bacteria. A total of 71 diazotrophic bacteria were isolated from soils of reforested area, organic fertilized field and chemically fertilized field, including Streptomyces, Burkholderia, Rhizobium and Micrococcus. We found that paraquat and phenylurea inhibited almost all diazotrophs we tested, and no isolate showed capability of utilizing them as nutrients. However, atrazine was less inhibitory and only less than half of tested isolates were inhibited. Besides, some isolates grew better in the presence of atrazine, suggested that they might be capable of using atrazine as nutrient. Streptomyces isolated from both organic farm and reforested area were highly susceptible to all 3 herbicides. We conclude that diazotrophic bacteria are likely to be eliminated when exposed to herbicide application in conventional agriculture practice and should be taken into consideration.
Key words: herbicides, soil diazotrophic bacteria
Microbial composition of a microbial mat collected from air conditioning cooling tower
Po-Ching Wu (吳柏青), Ya-Ting Hsu (許雅婷), Chun-Yao Chen (陳俊堯)
Department of Life Science, Tzu-Chi University
Urbanization leads to dramatic change in the environment and decline of many species. However, microbes could conquer this new environment and occupied niches not existing previously not existed in the city. In this study we describe microbial mat found on plastic fill of a cooling tower on a building. These mats are presumably self-sustaining for these is no apparent nutrient input, and are comparable to mats found in low nutrient freshwater streams with continuous water flow. The side of the mat directly facing the sun is light brown or orange in color, and shaded side is more greenish in color, suggesting at least two groups of phototrophs with apparent niche preference. We adopted the 16S rDNA massive parallel sequencing technique to examine the bacterial composition. A total of 396 OTUs with relative abundance over 0.01% were identified. The mat is dominated by Cyanobacteria (68%), which is composed of one OTU unable to be classified to known taxa (37% of total sequences), and two other subsection III OTUs (21% and 10%, respectively). Proteobacteria (8%) and Bacteroidetes (1.2%) are the other 2 dominant phyla in the mat community. The cyanobacteria is the most likely source of carbon and nitrogen, and supports the mat system, where not only bacteria but alga, nematodes and arthropods can survive.
Key words: cooling tower, microbial composition, cyanobacteria
Po-Ching Wu (吳柏青), Ya-Ting Hsu (許雅婷), Chun-Yao Chen (陳俊堯)
Department of Life Science, Tzu-Chi University
Urbanization leads to dramatic change in the environment and decline of many species. However, microbes could conquer this new environment and occupied niches not existing previously not existed in the city. In this study we describe microbial mat found on plastic fill of a cooling tower on a building. These mats are presumably self-sustaining for these is no apparent nutrient input, and are comparable to mats found in low nutrient freshwater streams with continuous water flow. The side of the mat directly facing the sun is light brown or orange in color, and shaded side is more greenish in color, suggesting at least two groups of phototrophs with apparent niche preference. We adopted the 16S rDNA massive parallel sequencing technique to examine the bacterial composition. A total of 396 OTUs with relative abundance over 0.01% were identified. The mat is dominated by Cyanobacteria (68%), which is composed of one OTU unable to be classified to known taxa (37% of total sequences), and two other subsection III OTUs (21% and 10%, respectively). Proteobacteria (8%) and Bacteroidetes (1.2%) are the other 2 dominant phyla in the mat community. The cyanobacteria is the most likely source of carbon and nitrogen, and supports the mat system, where not only bacteria but alga, nematodes and arthropods can survive.
Key words: cooling tower, microbial composition, cyanobacteria
Microbial composition of a Leptolyngbya-dominated microbial mat in an oligotrophic freshwater pond
Peng-Ling Yu (彭鈴育), Ya-Ting Hsu (許雅婷), Chun-Yao Chen (陳俊堯) Department of Life Science, Tzu-Chi University
Microbial mat is an aggregate where high diversity of microbes co-exist. Microbial mats in extreme or marine environments have been studied, however, we know relatively little about the freshwater mats. In this study we described the microbial composition of a sturdy microbial mat found in freshwater pond inside the campus of Tzu-Chi University. The mats are light brown in color, have relatively firm structure, and were found attached to stones just above water line. These mats grew slowly and growth can be seen over a period of several weeks. Under dissecting microscope, the mat can be classified into brown, translucent, green and dark layers according to representative colors. Sections of the mat revealed that at least two types of filamentous microbes, presumably cyanobacteria, were the dominant structural component of the microbial mat. We adopted the 16S rDNA massive parallel sequencing technique to examine the bacterial composition. A total of 186 OTUs with relative abundance over 0.01% were identified. The mat is dominated by Cyanobacteria (71%), and Leptolyngbya alone constituted 67% of bacterial community. Other dominating phyla include Bacteroidetes (7%) and Proteobacteria (6%). Only 5 out of the 20 dominant OTUs could be classified to known genera, suggesting most of the members in this community are novel species.
Key words: microbial mat, oligotrophic freshwater pond, microbial composition
Peng-Ling Yu (彭鈴育), Ya-Ting Hsu (許雅婷), Chun-Yao Chen (陳俊堯) Department of Life Science, Tzu-Chi University
Microbial mat is an aggregate where high diversity of microbes co-exist. Microbial mats in extreme or marine environments have been studied, however, we know relatively little about the freshwater mats. In this study we described the microbial composition of a sturdy microbial mat found in freshwater pond inside the campus of Tzu-Chi University. The mats are light brown in color, have relatively firm structure, and were found attached to stones just above water line. These mats grew slowly and growth can be seen over a period of several weeks. Under dissecting microscope, the mat can be classified into brown, translucent, green and dark layers according to representative colors. Sections of the mat revealed that at least two types of filamentous microbes, presumably cyanobacteria, were the dominant structural component of the microbial mat. We adopted the 16S rDNA massive parallel sequencing technique to examine the bacterial composition. A total of 186 OTUs with relative abundance over 0.01% were identified. The mat is dominated by Cyanobacteria (71%), and Leptolyngbya alone constituted 67% of bacterial community. Other dominating phyla include Bacteroidetes (7%) and Proteobacteria (6%). Only 5 out of the 20 dominant OTUs could be classified to known genera, suggesting most of the members in this community are novel species.
Key words: microbial mat, oligotrophic freshwater pond, microbial composition
Microbial composition of orchid Spiranthes sinensis rhizosphere
Chi-Lung Ma (馬啟隆), Nai-Hsuan Yang (楊乃璇), Chun-Yao Chen (陳俊堯)
Department of Life Sciences, Tzu-Chi University, Hualien
Spiranthes sinensis is a species of orchid. This species flowers in late spring, and the leaves slough off the plant after flowering, with all above ground biomass disappears during summer. This lack of photosynthetic carbon supply may cause dramatic change in plant physiology, and may impact rhizosphere microbiota through changes in root secretion. In this study we followed the microbial dynamics in rhizosphere during a 1-year period, using S. sinensis collected from 2 separate campuses of Tzu-Chi University. Proteobacteria (47%), Acidobacteria (19%), Planctomycetes (8%), Bacteroidetes (7%) and Actinobacteria (5%) dominated the rhizosphere microbiota. NMDS analysis result shows that plants collected from separate campuses have different microbiota. We observed a shift in microbial composition between flowering season and non-flowering season, and similar taxonomic change in microbial composition was seen in plants collected from both campuses.
During the flowering season, there is an increase in Bacteroidetes and Cyanobacteria abundances, and decrease in Chloroflexi, Planctomycetes and Spirochaetes. We conclude that both site and plant physiology can affect rhizosphere microbial composition of S. sinensis.
Key words: Spiranthes sinensis, rhizosphere microbiota
Chi-Lung Ma (馬啟隆), Nai-Hsuan Yang (楊乃璇), Chun-Yao Chen (陳俊堯)
Department of Life Sciences, Tzu-Chi University, Hualien
Spiranthes sinensis is a species of orchid. This species flowers in late spring, and the leaves slough off the plant after flowering, with all above ground biomass disappears during summer. This lack of photosynthetic carbon supply may cause dramatic change in plant physiology, and may impact rhizosphere microbiota through changes in root secretion. In this study we followed the microbial dynamics in rhizosphere during a 1-year period, using S. sinensis collected from 2 separate campuses of Tzu-Chi University. Proteobacteria (47%), Acidobacteria (19%), Planctomycetes (8%), Bacteroidetes (7%) and Actinobacteria (5%) dominated the rhizosphere microbiota. NMDS analysis result shows that plants collected from separate campuses have different microbiota. We observed a shift in microbial composition between flowering season and non-flowering season, and similar taxonomic change in microbial composition was seen in plants collected from both campuses.
During the flowering season, there is an increase in Bacteroidetes and Cyanobacteria abundances, and decrease in Chloroflexi, Planctomycetes and Spirochaetes. We conclude that both site and plant physiology can affect rhizosphere microbial composition of S. sinensis.
Key words: Spiranthes sinensis, rhizosphere microbiota
Site effect is more important than tree effect in determining soil microbiota in Danong-Dafu reforested area
Yu-Liang Lin (林玉玲), Ya-Ting Hsu (許雅婷), Chun-Yao Chen (陳俊堯)
Department of Life Sciences, Tzu-Chi University, Hualien
Composition of soil microbiota can be influenced by both local soil properties and properties of the nearly plants. The Danong-Dafu reforested area provide a good chance for us to study the impact of tree species on soil microbiota. Two area were selected for sampling, and in each area one single species stand and one mixed species stand were selected to study soil microbiota. Sampling were performed on soil either beside the tree (close to tree) or in the midpoint between two trees (away from tree). The soil microbiota were analyzed using 16S rDNA massive parallel sequencing techniques. The microbiota are dominated by Proteobacteria, Acidobacteria, Verrucomicrobia and Cyanobacteria. NMDS analysis using genus-level OTU showed that samples from the same site tend to have more similar composition. The trend is less clear when phylum-level compositions were used, indicating that divergence among sites occurs at lower taxonomic levels. Within the same site, the “close to tree” microbiota are different from "away from tree” ones. Microbiota in the single species stands are slightly less divergent than those in mixed species stands. There seems to be no specificity in microbiota to tree species. We conclude that in Danong-Dafu area, sampling site has the biggest effect on microbiota composition.
Key words: Danong-Dafu, soil microbiota
Yu-Liang Lin (林玉玲), Ya-Ting Hsu (許雅婷), Chun-Yao Chen (陳俊堯)
Department of Life Sciences, Tzu-Chi University, Hualien
Composition of soil microbiota can be influenced by both local soil properties and properties of the nearly plants. The Danong-Dafu reforested area provide a good chance for us to study the impact of tree species on soil microbiota. Two area were selected for sampling, and in each area one single species stand and one mixed species stand were selected to study soil microbiota. Sampling were performed on soil either beside the tree (close to tree) or in the midpoint between two trees (away from tree). The soil microbiota were analyzed using 16S rDNA massive parallel sequencing techniques. The microbiota are dominated by Proteobacteria, Acidobacteria, Verrucomicrobia and Cyanobacteria. NMDS analysis using genus-level OTU showed that samples from the same site tend to have more similar composition. The trend is less clear when phylum-level compositions were used, indicating that divergence among sites occurs at lower taxonomic levels. Within the same site, the “close to tree” microbiota are different from "away from tree” ones. Microbiota in the single species stands are slightly less divergent than those in mixed species stands. There seems to be no specificity in microbiota to tree species. We conclude that in Danong-Dafu area, sampling site has the biggest effect on microbiota composition.
Key words: Danong-Dafu, soil microbiota
Composition and resilience of deep sea bacterial communities when facing natural environmental disturbance
Yvan Chen (陳沅孟)1, Chun-Yao Chen (陳俊堯)2
Stone and Resource Industry R & D Center, Hualien1, Department of Life Sciences, Tzu-Chi University, Hualien2
Biodiversity in marine environments is a fascinating topic for biologists. Compared to surface water, the microbial composition and physiology in deep sea and sea bottom remain relatively unknown. In this study we examined variation in deep sea water microbial diversity in Hualien and Taitung. The communities were dominated by Proteobacteria (69%), Bacteroidetes (7%), SAR406 (6%), Chloroflexi (5%) and Actinobacteria (4%). The composition is very different from that of surface water, with apparent reduction in Proteobacteria and Bacteroidetes. Despite difference in geographic location and deapth, deep sea communities in Hualien (662 m) and Taitung (319 m and 430 m) were similar in composition. We monitored the composition during the day from 9:00 to 15:00 and the observed variation was minimal. However, natural disturbance such as typhoon can still lead to change. We monitored changes in microbiota before and after Typhoon Soudelor in 2015. Even at 662 m below surface, typhoon led to dramatic change in microbial composition, with increase in Proteobacteria and decreases in Bacteroidetes, SAR406, and Chloroflexi. Both SAR406 and Chloroflexi showed recovery 6 days after typhoon. These suggest that deep sea environments are relatively stable when facing daily fluctuatings but typhoon can lead to major change in composition.
Key words: deep sea water, microbial composition, typhoon
Yvan Chen (陳沅孟)1, Chun-Yao Chen (陳俊堯)2
Stone and Resource Industry R & D Center, Hualien1, Department of Life Sciences, Tzu-Chi University, Hualien2
Biodiversity in marine environments is a fascinating topic for biologists. Compared to surface water, the microbial composition and physiology in deep sea and sea bottom remain relatively unknown. In this study we examined variation in deep sea water microbial diversity in Hualien and Taitung. The communities were dominated by Proteobacteria (69%), Bacteroidetes (7%), SAR406 (6%), Chloroflexi (5%) and Actinobacteria (4%). The composition is very different from that of surface water, with apparent reduction in Proteobacteria and Bacteroidetes. Despite difference in geographic location and deapth, deep sea communities in Hualien (662 m) and Taitung (319 m and 430 m) were similar in composition. We monitored the composition during the day from 9:00 to 15:00 and the observed variation was minimal. However, natural disturbance such as typhoon can still lead to change. We monitored changes in microbiota before and after Typhoon Soudelor in 2015. Even at 662 m below surface, typhoon led to dramatic change in microbial composition, with increase in Proteobacteria and decreases in Bacteroidetes, SAR406, and Chloroflexi. Both SAR406 and Chloroflexi showed recovery 6 days after typhoon. These suggest that deep sea environments are relatively stable when facing daily fluctuatings but typhoon can lead to major change in composition.
Key words: deep sea water, microbial composition, typhoon