ISME 15 國際微生物生態學會年會. Seoul, Korea
Tadpole gut microbiota of Kurixalus eiffingeri: a tree frog raising their youngs in bamboo stomps
Ya-Ting Hsu1,2, Chun-Yao Chen1, Yung-Hsin Chang1, Han-Chen Ho2
1 Department of Life Sciences, Tzu Chi University
2 Department of Anatomy, Tzu Chi University
A stable and balanced gut microbiota helps the host animal to stay healthy. Gut microbes may be passed down from generation to generation in terrestrial vertebrates. However, larval fish and amphibians usually do not live with their parents, therefore, their gut microbes are mostly obtained through environmental sources. Here we present the gut microbiota of Kurixalus eiffingeri, an amphibian species raises their tadpoles in bamboo stomps and feeds them with unfertilized eggs. We suspected that the feeding behavior increases the chance of K. eiffingeri tadpoles in getting adult gut microbes. The K. eiffingeri tadpole gut 16S rDNA library is composed of Proteobacteria (50.9%), Verrucomicrobia (26.9%), Bacteroidetes (16.3%), Firmicutes (4.9%), and Actinobacteria (1.0%). Bacteroidetes, one of the major phylum found in the gut of terrestrial vertebrates, constituted a significant part of K. eiffingeri tadpole gut community, indicating that the mammalian type microbial symbiosis may have been established in amphibians. DGGE analysis indicated the presence of shared members between tadpole gut and environmental samples, and between tadpoles and their parents. This result shows that both the environment and parents serve as sources of tadpole gut microbes. In conclusion, we demonstrated that K. eiffingeri tadpoles obtain their gut microbiota partly from their parents, and may already have symbiotic relationship with gut bacteria, similar to that found in mammals.
1 Department of Life Sciences, Tzu Chi University
2 Department of Anatomy, Tzu Chi University
A stable and balanced gut microbiota helps the host animal to stay healthy. Gut microbes may be passed down from generation to generation in terrestrial vertebrates. However, larval fish and amphibians usually do not live with their parents, therefore, their gut microbes are mostly obtained through environmental sources. Here we present the gut microbiota of Kurixalus eiffingeri, an amphibian species raises their tadpoles in bamboo stomps and feeds them with unfertilized eggs. We suspected that the feeding behavior increases the chance of K. eiffingeri tadpoles in getting adult gut microbes. The K. eiffingeri tadpole gut 16S rDNA library is composed of Proteobacteria (50.9%), Verrucomicrobia (26.9%), Bacteroidetes (16.3%), Firmicutes (4.9%), and Actinobacteria (1.0%). Bacteroidetes, one of the major phylum found in the gut of terrestrial vertebrates, constituted a significant part of K. eiffingeri tadpole gut community, indicating that the mammalian type microbial symbiosis may have been established in amphibians. DGGE analysis indicated the presence of shared members between tadpole gut and environmental samples, and between tadpoles and their parents. This result shows that both the environment and parents serve as sources of tadpole gut microbes. In conclusion, we demonstrated that K. eiffingeri tadpoles obtain their gut microbiota partly from their parents, and may already have symbiotic relationship with gut bacteria, similar to that found in mammals.
Effect of different land use on the composition and stability of soil microbial communities
Pei-Yu Hou1, Shih-Chieh Chang2, Chun-Yao Chen1
1 Department of Life Sciences, Tzu Chi University
2 Department of Natural Resources and Environmental Studies, National Dong Hwa University
Land use type could alter soil microbial composition and therefore ecological function. Here we presented the 1-year dynamics of bacterial and archaeal communities in 3 types of land, including organically-fertilized (OR) farmland, chemically-fertilized (CH) farmland, and reforested (FO) land. These lands were all used for growing sugarcane but shifted to different land use practice about 10 years ago. Soil samples were taken and analyzed every season, and the community structure was monitored using DGGE analysis. The microbial composition fluctuated greatly in CH land, but stayed relatively stable in OR and FO lands. Community composition based on 16S rDNA clone libraries showed that FO land bacterial communities were dominated by Acidobacteria, but Proteobacteria dominated OR and CH communities. Archaeal communities in all soils were almost entirely composed of Thaumarchaeota. The dominant lineage in FO soils was Terrestrial Group, but in OR and CH soils, SAGMCG-1 was more abundant. The microcosm studies showed that high temperature/desiccation stress increased the relative abundance of Soil Crenarchaeotic Group. Our results showed changes in land use practice, especially crop cultivation has significant effect on community composition and stability.
1 Department of Life Sciences, Tzu Chi University
2 Department of Natural Resources and Environmental Studies, National Dong Hwa University
Land use type could alter soil microbial composition and therefore ecological function. Here we presented the 1-year dynamics of bacterial and archaeal communities in 3 types of land, including organically-fertilized (OR) farmland, chemically-fertilized (CH) farmland, and reforested (FO) land. These lands were all used for growing sugarcane but shifted to different land use practice about 10 years ago. Soil samples were taken and analyzed every season, and the community structure was monitored using DGGE analysis. The microbial composition fluctuated greatly in CH land, but stayed relatively stable in OR and FO lands. Community composition based on 16S rDNA clone libraries showed that FO land bacterial communities were dominated by Acidobacteria, but Proteobacteria dominated OR and CH communities. Archaeal communities in all soils were almost entirely composed of Thaumarchaeota. The dominant lineage in FO soils was Terrestrial Group, but in OR and CH soils, SAGMCG-1 was more abundant. The microcosm studies showed that high temperature/desiccation stress increased the relative abundance of Soil Crenarchaeotic Group. Our results showed changes in land use practice, especially crop cultivation has significant effect on community composition and stability.
第19屆細菌學研討會. 高雄
除草劑對土壤分離固氮菌的影響
陳俊堯1、陳樂章2、楊里澤2、杜禹昇2、黃鈺珉2、楊乃璇1
1慈濟大學生命科學系
2慈濟大學附屬高級中學
土地利用方式對土壤微生物群聚的組成與功能可能造成顯著影響。慣行農田裡施用的肥料及農藥,均有可能藉由選擇性促進或抑制特定菌群的生長或功能。我們從沒有經歷過慣行農法(使用有機肥、未用除草劑)的校園裡,選擇竹林、草生地、操場、菜園等四個樣區的土壤樣本, 以Azotobacter medium分離固氮菌。我們共計分離 109 株細菌,做為土壤中可培養固氮菌的代表。四個樣區分離得到的菌種接近。分離得到的菌株經 16S rDNA 定序鑑定,包括屬於Gammaproteobacteria 的 Enterobacteriaceae 和Pseudomonas、Alphaproteobactreia 的Sphingomonadaeae和Brevundimonas、Betaprooteobacteria 的 Oxalobacteriaceae和Comamonadaceae,其中以 Enterobacteriaceae 數量佔多數。這些菌株中的三株細菌在配成菌液添加在土壤中後證實具有促進小白菜的生長的效果。本研究測試這些菌株的生長是否受到田間常用的三種除草劑 triazine, phenylurea, 和 paraquat。Paraquat 的影響明顯,在建議施用濃度 1/10 (120 mg/L)時有19.3%的受測菌株生長受到抑制。Triazine 和 phenylurea 的影響不大,受測細菌在建議施用濃度 1/10時(triazine為250 mg/L,dimethylurea為 400 mg/L)均僅有2.8%會受到抑制。本研究結果顯示除草劑 paraquat 的施用,可能造成土壤中固氮細菌的組成。
1慈濟大學生命科學系
2慈濟大學附屬高級中學
土地利用方式對土壤微生物群聚的組成與功能可能造成顯著影響。慣行農田裡施用的肥料及農藥,均有可能藉由選擇性促進或抑制特定菌群的生長或功能。我們從沒有經歷過慣行農法(使用有機肥、未用除草劑)的校園裡,選擇竹林、草生地、操場、菜園等四個樣區的土壤樣本, 以Azotobacter medium分離固氮菌。我們共計分離 109 株細菌,做為土壤中可培養固氮菌的代表。四個樣區分離得到的菌種接近。分離得到的菌株經 16S rDNA 定序鑑定,包括屬於Gammaproteobacteria 的 Enterobacteriaceae 和Pseudomonas、Alphaproteobactreia 的Sphingomonadaeae和Brevundimonas、Betaprooteobacteria 的 Oxalobacteriaceae和Comamonadaceae,其中以 Enterobacteriaceae 數量佔多數。這些菌株中的三株細菌在配成菌液添加在土壤中後證實具有促進小白菜的生長的效果。本研究測試這些菌株的生長是否受到田間常用的三種除草劑 triazine, phenylurea, 和 paraquat。Paraquat 的影響明顯,在建議施用濃度 1/10 (120 mg/L)時有19.3%的受測菌株生長受到抑制。Triazine 和 phenylurea 的影響不大,受測細菌在建議施用濃度 1/10時(triazine為250 mg/L,dimethylurea為 400 mg/L)均僅有2.8%會受到抑制。本研究結果顯示除草劑 paraquat 的施用,可能造成土壤中固氮細菌的組成。
運用高糖培養篩選耐旱及幫助植物生長的細菌
陳俊堯1、王治勛2、余孟穎2、邱姿綺2、楊乃璇1
1慈濟大學生命科學系
2慈濟大學附屬高級中學
民間製作有機液肥常將利用糖蜜,從土壤或水果中來進行益菌增殖。此過程中使用的高糖與高滲透壓條件可能是從環境中得到對植物有益細菌的篩選機制。本研究中嘗試以高蔗糖培養基直接從環境樣本中培養菌種,並測試這些細菌的特性及對植物的影響。從包含各種水果、花、葉及土壤的 16 種樣本中,我們成功分離出 57 個菌株。這些菌株中的11株細菌,在配成菌液添加在土壤中後證實具有促進小白菜的生長的效果,顯示高糖份培養基可以篩選出有益植物生長的菌種。這些菌株經鑑定為Bacillus及Enterobacteriaceae新種菌種,其中以Enterobacter最多。我們推測能在高糖培養基生長的細菌,可能較適應高滲透壓環境而有較能耐旱。這些菌株在進行40°C乾旱處理6小時後,所有菌株均能存活。我們比較菌株們在一般培養基或添加蔗糖培養兩小時後,再給予乾旱處理。乾旱1.5小時後有19%的菌株在高糖培養後存活較佳, 乾旱6小時後比例更提高到37%,顯示這些細菌能在經歷高糖處理後提高對乾旱的耐受性。在高蔗糖培養基形成黏性菌落的菌種均在高糖處理後提高耐旱能力,顯示生成細胞外多醣可能有助於幫助細菌在環境中存活。
1慈濟大學生命科學系
2慈濟大學附屬高級中學
民間製作有機液肥常將利用糖蜜,從土壤或水果中來進行益菌增殖。此過程中使用的高糖與高滲透壓條件可能是從環境中得到對植物有益細菌的篩選機制。本研究中嘗試以高蔗糖培養基直接從環境樣本中培養菌種,並測試這些細菌的特性及對植物的影響。從包含各種水果、花、葉及土壤的 16 種樣本中,我們成功分離出 57 個菌株。這些菌株中的11株細菌,在配成菌液添加在土壤中後證實具有促進小白菜的生長的效果,顯示高糖份培養基可以篩選出有益植物生長的菌種。這些菌株經鑑定為Bacillus及Enterobacteriaceae新種菌種,其中以Enterobacter最多。我們推測能在高糖培養基生長的細菌,可能較適應高滲透壓環境而有較能耐旱。這些菌株在進行40°C乾旱處理6小時後,所有菌株均能存活。我們比較菌株們在一般培養基或添加蔗糖培養兩小時後,再給予乾旱處理。乾旱1.5小時後有19%的菌株在高糖培養後存活較佳, 乾旱6小時後比例更提高到37%,顯示這些細菌能在經歷高糖處理後提高對乾旱的耐受性。在高蔗糖培養基形成黏性菌落的菌種均在高糖處理後提高耐旱能力,顯示生成細胞外多醣可能有助於幫助細菌在環境中存活。