由加拿大科学家凯西·休伯特率领的一个国际研究小组,在挪威附近的北冰洋下低于摄氏零度的沉积物中,发现了一种数目不菲、处于冬眠状态的嗜热菌。这种细菌以细菌芽孢状态存在,在低于零摄氏度的海底冬眠。该项发现有可能使科学家有机会追踪到来自海底以下的热环境中渗出的热流,从而可能利用这种手段找到海底蕴藏的石油和天然气。相关研究报告发表在9月18日出版的《科学》杂志上。
研究小组发现,这种嗜热菌以孢子形式冬眠于北冰洋海底的沉积物中,这样可以抵御其所处的恶劣环境条件。他们进行的实验显示,在摄氏40度到摄氏60度之间,这些孢子就可以复活为细菌。因此科学家认为,这些冬眠细菌可能来自于大洋底部之下的某些热区域。
领导该项研究工作的休伯特博士目前接受加拿大自然科学和工程研究委员会的资助,在德国与多国科学家开展合作研究。他表示,最令他们关注的是,这种细菌与取自海底石油的细菌在遗传特征上有许多相似性。目前他们正在调查研究这些细菌究竟来自何处,如果这些细菌来自于某个泄漏的海底石油储藏地,那么这种细菌在今后的利用价值就显而易见了。
由于这些细菌属厌氧菌,而且其在海底沉积物中存量可观,源源不断,这显示它们来自于一个巨大的无氧生活环境。休伯特教授认为,一种可能是它们来自于大洋深处的高压原油储藏区域,向上泄漏的原油将其带入了海底水域。另一种可能是海底“黑烟囱”或其他热流口的存在,产生的热液流动将其带出。但这种嗜热菌究竟来自何处,还需要进一步研究实验确证。(生物谷Bioon.com)
生物谷推荐原始出处:
Science 18 September 2009:DOI: 10.1126/science.1174012
A Constant Flux of Diverse Thermophilic Bacteria into the Cold Arctic Seabed
Casey Hubert,1,* Alexander Loy,2 Maren Nickel,1 Carol Arnosti,3 Christian Baranyi,2 Volker Brüchert,1,Timothy Ferdelman,1 Kai Finster,4 Flemming M?nsted Christensen,4,5 Júlia Rosa de Rezende,1,5 Verona Vandieken,1, Bo Barker J?rgensen1,5
Microorganisms have been repeatedly discovered in environments that do not support their metabolic activity. Identifying and quantifying these misplaced organisms can reveal dispersal mechanisms that shape natural microbial diversity. Using endospore germination experiments, we estimated a stable supply of thermophilic bacteria into permanently cold Arctic marine sediment at a rate exceeding 108 spores per square meter per year. These metabolically and phylogenetically diverse Firmicutes show no detectable activity at cold in situ temperatures but rapidly mineralize organic matter by hydrolysis, fermentation, and sulfate reduction upon induction at 50°C. The closest relatives to these bacteria come from warm subsurface petroleum reservoir and ocean crust ecosystems, suggesting that seabed fluid flow from these environments is delivering thermophiles to the cold ocean. These transport pathways may broadly influence microbial community composition in the marine environment.
1 Biogeochemistry Group, Max Planck Institute for Marine Microbiology, Celsiusstrasse 1, D-28359 Bremen, Germany.
2 Department of Microbial Ecology, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria.
3 Department of Marine Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599–3300, USA.
4 Department of Biological Sciences–Microbiology Section, Aarhus University, Ny Munkegade, Building 1540, DK-8000 Aarhus C, Denmark.
5 Center for Geomicrobiology, Department of Biological Sciences, Aarhus University, Ny Munkegade, Building 1535, DK-8000 Aarhus C, Denmark.