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Title: | 以DNA穩定同位素探針技術探討臺灣亞熱帶人工濕地活性甲烷氧化菌結構 Composition of active methanotrophs in subtropical constructed wetlands in Taiwan with DNA stable isotope probing |
Authors: | 陳亭愷 Ting-Kai Chen |
Advisor: | 蕭友晉 Yo-Jin Shiau |
Keyword: | 人工濕地,甲烷氧化菌,顆粒甲烷單加氧酶,甲烷,穩定同位素探針技術,次世代定序, Constructed wetland,DNA Stable-isotope probing,Methanotroph,pmoA,Methane,Next generation sequencing, |
Publication Year : | 2023 |
Degree: | 碩士 |
Abstract: | 人工濕地作為生態工程技術,其封存碳的功能與天然濕地相似,並被視為降低全球溫室氣體濃度的自然為本解決方案。然而,濕地所提供的厭氧土壤條件也使其成為甲烷(CH4)排放的重要來源。在甲烷向上擴散的過程中,表層0-2公分好氧土壤層中的甲烷氧化菌,可以將深層濕地土壤產生的50至90% 甲烷可氧化為二氧化碳(CO2),進而緩和濕地的甲烷排放總量,促進濕地碳匯價值。過去研究顯示亞熱帶及熱帶地區濕地被認為可能主導著全球甲烷變化,然而以往有關甲烷氧化菌的研究主要集中在稻田和天然濕地,對於人工濕地的資料相對較少。
本研究利用DNA穩定同位素探針技術(DNA stable isotope probing;DNA-SIP)和次世代定序技術,分析臺灣夏冬兩季三個不同完工時間的人工濕地中活性甲烷氧化菌的群落結構變化。由pmoA及16S rRNA基因序列展示了人工濕地甲烷氧化菌不同的群落結構組成,與過去紅樹林土壤研究的結構類似。研究結果顯示,活性Type Ia甲烷氧化菌Methylomonas、Methylobacter、Methylosarcina主導了濕地的淨排放。冗餘分析及多變量線性迴歸分析探討環境因子對物種的影響,其中在年輕濕地中發現較高比例的Methylomonas可能是場域中高甲烷氧化能力物種,並且偏好酸性及C/N比較高的環境。通過相關性及網絡分析也展示活性Methylobacter與其他甲烷氧化菌間的負相關,及RPC-1、Methylomonas、Methylocystis之正相關。另外,高豐度的活性未分類Betaproteobacteria可能存在對土壤碳循環具重要作用的物種。本研究結果展示了人工濕地中甲烷氧化菌在不同條件下的生態位分化和活躍群落結構的變化,展望未來人工濕地管理應該加強其碳匯價值。 Constructed wetlands, as ecological engineering technologies have similar ecosystems services as natural wetlands in sequestrating carbon and are recognized as nature-based solutions in reducing the global greenhouse gas concentrations. However, the anaerobic soil conditions that wetlands provide also make them considerable sources for methane (CH4) emissions. Fortunately, 50 to 90 % of the CH4 produced from deep wetland soils can be oxidized into carbon dioxide (CO2) by methanotrophs in the aerobic soil layer, reducing the overall CH4 emissions from wetlands. Previous studies on methanotrophs have mostly be under taken in rice paddy and natural wetlands, while overlooked constructed wetlands, particularly in tropical and subtropical areas. This study analyzed the changes of active methanotrophs in three constructed wetlands with different ages in Taiwan in summer and winter. With using DNA stable isotope probing (DNA-SIP) and next-generation sequencing techniques, we revealed the temporal and spatial variations of active methanotrophic compositions in the constructed wetlands. The results from pmoA genes of DNA-SIP showed that the highest relative abundance of type Ia Methylomonas, Methylobacter, Methylosarcina were dominated all the studied constructed wetlands. Redundancy analysis and multiple linear regression analysis revealed a higher relative abundance of Methylomonas in young wetlands, indicating their greater methane oxidation capability in the field. Methylomonas also exhibited a preference for acidic and high C/N ratio environments. Additionally, spearman correlation and network analysis demonstrated negative co-occurence of species between genera of active Methylobacter and others, while interactions between RPC-1, Methylomonas, Methylocystis correlated positively. Furthermore, the high abundance of active unclassified betaproteobacteria may play a significant role in soil carbon cycle. These results demonstrate the ecological niche differentiation of methanotrophs in constructed wetlands under different conditions and the active community structure changes in response to methane concentration. Future management in constructed wetlands will be needed to enhance their carbon sequestration value. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/88682 |
DOI: | 10.6342/NTU202301073 |
Fulltext Rights: | 未授權 |
Appears in Collections: | 生物環境系統工程學系 |
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ntu-111-2.pdf Restricted Access | 6.98 MB | Adobe PDF |
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