Plymouth Marine Laboratory, Plymouth, UK.
ISME J. 2013 Mar;7(3):568-80. doi: 10.1038/ismej.2012.130. Epub 2012 Nov 22.
Methanol biogeochemistry and its importance as a carbon source in seawater is relatively unexplored. We report the first microbial methanol carbon assimilation rates (k) in productive coastal upwelling waters of up to 0.117±0.002 d(-1) (~10 nmol l(-1 )d(-1)). On average, coastal upwelling waters were 11 times greater than open ocean northern temperate (NT) waters, eight times greater than gyre waters and four times greater than equatorial upwelling (EU) waters; suggesting that all upwelling waters upon reaching the surface (≤20 m), contain a microbial population that uses a relatively high amount of carbon (0.3-10 nmol l(-1 )d(-1)), derived from methanol, to support their growth. In open ocean Atlantic regions, microbial uptake of methanol into biomass was significantly lower, ranging between 0.04-0.68 nmol l(-1 )d(-1). Microbes in the Mauritanian coastal upwelling used up to 57% of the total methanol for assimilation of the carbon into cells, compared with an average of 12% in the EU, and 1% in NT and gyre waters. Several methylotrophic bacterial species were identified from open ocean Atlantic waters using PCR amplification of mxaF encoding methanol dehydrogenase, the key enzyme in bacterial methanol oxidation. These included Methylophaga sp., Burkholderiales sp., Methylococcaceae sp., Ancylobacter aquaticus, Paracoccus denitrificans, Methylophilus methylotrophus, Methylobacterium oryzae, Hyphomicrobium sp. and Methylosulfonomonas methylovora. Statistically significant correlations for upwelling waters between methanol uptake into cells and both chlorophyll a concentrations and methanol oxidation rates suggest that remotely sensed chlorophyll a images, in these productive areas, could be used to derive total methanol biological loss rates, a useful tool for atmospheric and marine climatically active gas modellers, and air-sea exchange scientists.
甲醇的生物地球化学及其作为海水中碳源的重要性尚未得到充分研究。我们首次报道了生产力较高的沿海上升流海域中微生物甲醇碳同化率（k）可达 0.117±0.002 d(-1)（~10 nmol l(-1 )d(-1)）。平均而言，上升流海域的甲醇同化率是开阔海域北温带（NT）海域的 11 倍，是环流海域的 8 倍，是赤道上升流海域的 4 倍；这表明，所有上升流海域在到达海面（≤20 米）时，都含有一个微生物种群，该种群使用相对大量的碳（0.3-10 nmol l(-1 )d(-1)），主要来源于甲醇，以支持其生长。在开阔的大西洋海域，甲醇被微生物吸收并转化为生物量的速率显著较低，范围在 0.04-0.68 nmol l(-1 )d(-1)之间。在毛里塔尼亚沿海上升流中，微生物将甲醇同化到细胞中的碳量高达 57%，而在 EU 海域的平均同化率为 12%，在 NT 和环流海域的同化率为 1%。使用聚合酶链反应（PCR）扩增编码甲醇脱氢酶的 mxaF 基因，从大西洋开阔海域的几种甲基营养细菌种属。这些细菌种属包括噬甲基菌属（Methylophaga sp.）、伯克霍尔德氏菌科（Burkholderiales sp.）、甲基球菌科（Methylococcaceae sp.）、水生不动杆菌（Ancylobacter aquaticus）、脱氮副球菌（Paracoccus denitrificans）、甲基杆菌（Methylophilus methylotrophus）、稻垣菌（Methylobacterium oryzae）、黄杆菌（Hyphomicrobium sp.）和甲基磺酸单胞菌（Methylosulfonomonas methylovora）。上升流海域中甲醇被细胞吸收与叶绿素 a 浓度和甲醇氧化速率之间存在显著的相关性，这表明在这些生产力较高的海域，可以使用遥感叶绿素 a 图像来推断总甲醇的生物损耗率，这是大气和海洋气候活跃气体模型和空气-海洋交换科学家的有用工具。
