Soil microbial community responses to additions of organic carbon substrates and heavy metals (Pb and Cr)
Soil microbial community responses to additions of organic carbon substrates and heavy metals (Pb and Cr)
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DOI：
10.1128/aem.71.12.7679-7689.2005
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发表时间：
2005-12-01
影响因子：
4.4
通讯作者：
Konopka, A
中科院分区：
文献类型：
--
作者：
Nakatsu, CH;Carmosini, N;Konopka, A
通过微宇宙实验研究了重金属（Pb、Cr）和芳烃污染对土壤微生物群落结构和功能的影响。添加有机基质作为微生物群落变化的驱动力。葡萄糖是各种细菌使用的能源，而预计使用二甲苯的土壤物种较少。金属修正案被选为抑制急性率的有机矿化的50%或90%，和较低的矿化率持续在整个31天的潜伏期。显着的生物量增加被取消时，除了有机碳添加金属。通过细菌16 S rRNA基因的PCR-变性梯度凝胶电泳检测到，单独添加有机碳对群落组成的影响最显著，并导致了一些优势菌型的增殖。然而，社区范围内的影响，重金属添加不同的两种碳源。对于葡萄糖，无论是铅或铬产生了很大的变化，并与新的钙离子类型的替代。与此相反，当添加任一种金属时，通过二甲苯处理选择的许多金属类型被保留。放线菌目的成员非常普遍的微观世界与二甲苯和铬（VI）;联苯双加氧酶和苯酚羟化酶（但不是其他加氧酶）的基因拷贝数升高，在这些微观世界中，通过实时PCR测定。抑制二甲苯催化剂所需的金属浓度比抑制葡萄糖催化剂所需的金属浓度低得多。在31天的培养过程中，Cr（VI）似乎减少了，但在葡萄糖的情况下，当大部分Cr（VI）残留时，仍有大量的微生物活性。在二甲苯的情况下，这一点不太清楚。
Microcosm experiments were conducted with soils contaminated with heavy metals (Pb and Cr) and aromatic hydrocarbons to determine the effects of each upon microbial community structure and function. Organic substrates were added as a driving force for change in the microbial community. Glucose represented an energy source used by a broad variety of bacteria, whereas fewer soil species were expected to use xylene. The metal amendments were chosen to inhibit the acute rate of organic mineralization by either 50% or 90%, and lower mineralization rates persisted over the entire 31-day incubation period. Significant biomass increases were abolished when metals were added in addition to organic carbon. The addition of organic carbon alone had the most significant impact on community composition and led to the proliferation of a few dominant phylotypes, as detected by PCR-denaturing gradient gel electrophoresis of bacterial 16S rRNA genes. However, the community-wide effects of heavy metal addition differed between the two carbon sources. For glucose, either Pb or Cr produced large changes and replacement with new phylotypes. In contrast, many phylotypes selected by xylene treatment were retained when either metal was added. Members of the Actinomycetales were very prevalent in microcosms with xylene and Cr(VI); gene copy numbers of biphenyl dioxygenase and phenol hydroxylase (but not other oxygenases) were elevated in these microcosms, as determined by real-time PCR. Much lower metal concentrations were needed to inhibit the catabolism of xylene than of glucose. Cr(VI) appeared to be reduced during the 31-day incubations, but in the case of glucose there was substantial microbial activity when much of the Cr(VI) remained. In the case of xylene, this was less clear.