Pringault Olivier, Duran Robert, Jacquet Séverine, Torréton Jean-Pascal
Unité de Recherche 103, Centre IRD de Nouméa, BP A5, 98848 Nouméa Cedex, New Caledonia.
Microb Ecol. 2008 Feb;55(2):247-58. doi: 10.1007/s00248-007-9272-8. Epub 2007 Jun 27.
Temporal variations of oxygen consumption, sensitivity to metal spiking, and microbial diversity were investigated during a one-year survey at the sediment-water interface in the tropical lagoon of New Caledonia. Sediment oxygen consumption (SOC) exhibited strong variations with time with maximum rates during February (Austral summer) and minimum values during July (cold period). SOC was strongly positively correlated with temperature, with an apparent activation energy (E (a)) of 41 kJ mol(-1), corresponding to an apparent Q (10)(20-30 degrees C) of 1.75. Strong short-term variations of SOC were also observed with ratios between two consecutive samplings reaching up to twofold of magnitude within one week, whereas the maximum/minimum ratio over the whole year was equal to 2.73. In most cases, metal spiking led to a strong decrease of SOC; however, in a third of sampling dates, spiking did not significantly decrease activity. These periods of apparent metal tolerance were not characterized by a particular bacterial community structure. Bacterial community structure estimated from terminal restriction fragment length polymorphism (T-RFLP) analysis exhibited strong variations over the one-year survey, and no seasonality was observed for bacterial richness. However, on average, the Whittaker similarity index between two consecutive T-RFLP profiles was above 60% suggesting a relative stability of the bacterial community structure on the short timescale with prominent T-RFs representing on average more than 67% of relative abundance occurring over most of the year, whereas other T-RFs only occurred during some periods.
在新喀里多尼亚热带泻湖的沉积物 - 水界面进行的为期一年的调查中，研究了耗氧量、对金属添加的敏感性和微生物多样性的时间变化。沉积物耗氧量（SOC）随时间呈现出强烈变化，2月（南半球夏季）速率最高，7月（寒冷期）最低。SOC与温度呈强烈正相关，表观活化能（E(a)）为41 kJ mol(-1)，对应于表观Q(10)(20 - 30摄氏度)为1.75。还观察到SOC的强烈短期变化，连续两次采样之间的比率在一周内可达两倍，而全年的最大/最小比率等于2.73。在大多数情况下，添加金属会导致SOC大幅下降；然而，在三分之一的采样日期，添加金属并没有显著降低活性。这些明显的金属耐受期并没有特定的细菌群落结构特征。通过末端限制性片段长度多态性（T - RFLP）分析估计的细菌群落结构在为期一年的调查中呈现出强烈变化，未观察到细菌丰富度的季节性。然而，平均而言，两个连续T - RFLP图谱之间的惠特克相似性指数高于60%，这表明细菌群落结构在短时间尺度上具有相对稳定性，主要的T - RFs平均相对丰度超过67%，在一年中的大部分时间出现，而其他T - RFs只在某些时期出现。
