Efficient aquatic bacterial metabolism of dissolved low-molecular-weight compounds from terrestrial sources
Efficient aquatic bacterial metabolism of dissolved low-molecular-weight compounds from terrestrial sources
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DOI：
10.1038/ismej.2009.120
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发表时间：
2010-03-01
期刊：
影响因子：
11
通讯作者：
Jansson, Mats
中科院分区：
文献类型：
--
作者：
Berggren, Martin;Laudon, Hjalmar;Jansson, Mats
游离态的羧酸(CA)、氨基酸(AAs)和碳水化合物(CHS)很容易被水生细菌吸收，并以高生长效率进行代谢。以前的研究表明，这些低分子量(LMW)底物是由浮游植物释放的，但也有来自陆地的不明LMW化合物是对非生产性淡水系统中细菌新陈代谢的补贴。我们验证了不同陆源的CA、AA和CH化合物可以为以异地溶解有机物(DOM)为主的淡水中的水生细菌代谢提供实质性支持的假设。采用为期2周的生物测定方法，对瑞典北部Krykerlan试验区3个不同性质的流域的排水在春季洪水涨落支处进行了研究。多种CA、AA和CH化合物被细菌显著同化，满足细菌碳需求的15%-100%，并解释了细菌生长效率的大部分变化(BGE；R2=0.66)。在检测到的29种化学物质中，醋酸盐是最重要的，占所有低分子化合物细菌总消耗量的45%。我们认为，北方春季洪水排水中的低分子有机化合物可能支持春季洪水后几周至几个月期间接收湖水中的所有原位细菌产生。《ISME期刊》(2010年)4,408-416；doi：10.1038/ismej.2009.120；2009年11月12日在线发布
Carboxylic acids (CAs), amino acids (AAs) and carbohydrates (CHs) in dissolved free forms can be readily assimilated by aquatic bacteria and metabolized at high growth efficiencies. Previous studies have shown that these low-molecular-weight (LMW) substrates are released by phytoplankton but also that unidentified LMW compounds of terrestrial origin is a subsidy for bacterial metabolism in unproductive freshwater systems. We tested the hypothesis that different terrestrially derived CA, AA and CH compounds can offer substantial support for aquatic bacterial metabolism in fresh waters that are dominated by allochthonous dissolved organic matter (DOM). Drainage water from three catchments of different characters in the Krycklan experimental area in Northern Sweden were studied at the rising and falling limb of the spring flood, using a 2-week bioassay approach. A variety of CA, AA and CH compounds were significantly assimilated by bacteria, meeting 15-100% of the bacterial carbon demand and explaining most of the observed variation in bacterial growth efficiency (BGE; R-2 = 0.66). Of the 29 chemical species that was detected, acetate was the most important, representing 45% of the total bacterial consumption of all LMW compounds. We suggest that LMW organic compounds in boreal spring flood drainage could potentially support all in situ bacterial production in receiving lake waters during periods of weeks to months after the spring flood. The ISME Journal (2010) 4, 408-416; doi:10.1038/ismej.2009.120; published online 12 November 2009