Earth Science Frontiers ›› 2008, Vol. 15 ›› Issue (6): 177-184.

• Article • Previous Articles     Next Articles

Vertical distribution of the microbial community in modern lacustrine sediments of Taihu Lake.

  

  1. 1State Key Laboratory for Mineral Deposit Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210093, China
    2State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, China

  • Online:2008-06-20 Published:2008-06-20

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Abstract:

The paper studies the physicochemical characteristics, nutritions and the microbial community diversity of sediment core samples in the Taihu Lake with fumigationdigestion and PCRDGGE analysis. The results indicated that the watersediment interface was in a state of mild reduction. Below the surface of sediments, Eh decreased rapidly with the increase in depth, and it is under the anaerobic condition except the top 80 cm layer of the sediment; in the depth ranging from 150 to 225 cm, the Eh value is basically stable. Further increasing the depth of sediment layers, the Eh value increased in the “z” style. The pH value decreased first and then slowly increased with the increase in the depth of sediment layers; the pH value changed slightly in the profile of sediments and ranged from 72 to 76. The TN, TP and OM concentrations in sediments are high, and their maximum concentrations reached 2436 mg/g, 0731 mg/g and 3817%, respectively. Their vertical profiles showed that the TN and OM concentrations decreased with the increase in the depth of sediment layers. The TP concentration slowly decreased with the increase in the depth of sediment layers in the “z” style. There are prominent differences in microbial diversity spatially; the comparability and the dynamic characteristics of community structures between different sediment samples at different depth are different. In order to test the correlation of the parameters, the properties of the sediment samples were analyzed by correlating all the depth of the samples with pH, Eh, OM, TN, TP and the ShannonWeaver index (H′). The little significant correlation at the α = 0.05 level was observed between the environmental parameters. However, the TN concentration and the percentage of organic matter(OM) are significantly correlated. The microbial diversity is jointly affected by the nutrient, the physical, chemical and biological characteristics, etc.

Key words:

microbial diversity; sediment; vertical distribution; denaturing gradient gel electrophoresis (DGGE); 16S rDNA

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