The Study Of Microbial Ecology In Two Typical Mining Area In Shandong Province And Their Potentiality To Be Environmental Indicators

The dissertation presented studies of two typical metal deposits in ShanDong province. With field investigation and laboratory studies,we made surveys of microbial ecology in these two deposits area and explored the potentiality of them to be complemental environmental quality indicators. Spatial methods in microbial ecology were also well summarized for further study. The results provided theoretical and practical foundation to deposits' ecological restoration,microbial community behavior and the application of environmental quality assessment.The main results are presented as follows:The Zibo iron deposits were slightly contaminated and traditional environmental quality indices were hard to detect sensitive pollutions,not mention their biological effects.Biological indices were sensitive to environmental changes and can be use as complemental environmental safety indicators.In mild contaminated area where traditional pollution indices can hardly detect changes,microbial behaviors changed significantly according to the environmental conditions.The property thus accomplished the microbes' potentiality to be used as complemental safety indicators of environment.The effects of heavy metals and environmental parameters could be detected by environmental fitting methods and their effects as could be estimated by random permutation test.In this mild degree of contamination as Zibo iron deposit area, while Nemerow indices kept still in most of samples, microbial behaviors exhibited a dazzling diversity. With the increase of pH,BAS of microbial community could appear stimulated by certain kinds of metals.Higher physiological activities may not lead to greater biomass,the trade-off strategy between sustaining and developing may change with particular environments. Microbial indices could be affected by various environmental factors; therefore, it should be very careful to use the function of microbes to monitor specific contaminations.However, with proper analysis method, the effects from different environment factors could be evaluated.On the whole,the submission of microbial behaviors in detecting holistic qualities shows great promise for the future,however, the development of new relative methods and more broad data collection should also be required.Also it is difficult to use microbial parameters as environmental quality indices independently, but their application to supply complemental information to traditional environmental quality index is feasible and meaningful.The ordination patterns base on microbial parameters are valuable to determine the weighting of environmental factors,including toxic substances, in the influencing of environment, emphasizing on the biological aspects.We can modify traditional environmental quality indices and establish completely new environmental quality index, and here we named it BIO Index.In our study, the modified Nemerow Index had great differences with the origin one and that indicated the ignorance of traditional environmental index to biological influences. Furthermore, we calculated the BIO index based on total metal contents and available contents separated. The results were all different from the Nemerow index which suggested the effect of considering microbial behavior by imposing their weighting to toxic parameters.Of course, the selection of microbial parameters to information supplement must be of great consideration. In this study, we used microbial carbon, soil basic respiration, average well color development and Shannon index developed from BIOLOG panels. The collection represented the microbial community size, physiological activity and the ability in carbon utilization, which represented a comprehensive description of microbial activities. However, the mix up of parameters of different aspect can lead to confusion in data analysis for the co linearity in the origin data can not be detected primarily. In addition, the microbial parameters in our study were too rough to represent the subtle community structures.In the study of Zhaoyuan gold deposit, a broad rang of sample collection were applied. In this area, average concentrations of some kinds of metals (Pb, Cu and Cd) were higher than the safe level according to Chinese national environmental quality standard for soils.Single metal effects on microbes can be determined in laboratory but combined effects in nature fields were hard to distinguish. Statistic analyses were applied to determine the combing effects of heavy metals. Metal data was first explained by factor analysis so the original distribute structure of these metals could be detected and their combing effects can be determined. We found that combing effects of heavy metals in Zhaoyuan gold deposit can be detected by factor analysis and so the weighing of different metals can be estimated. Cd, Zn, and Pb were categorized together either in total and soluble metals. Cr, Ni, Fe, Mn did not show similarity in total metal contents but strongly assembled in soluble metals. Such a separation of metals showed a common source/origin of those which were clustered together, and implied their similar distribution patterns.However, PCs extracted with such a method did not correlate with microbial parameters in an accordant way; most of them even had positive correlation with Cmic BAS, BIOLOG PCs. That means a higher concentration of heavy metals promote microbes'growth, which is in violent contrast with previous studies. However, these studies were carried out in conditions where study areas were deeply polluted and so metal concentration played a major role in influencing microbial behavior. In our study, as all samples were collected from farm filed, metal concentration did not go to such a high level that it could influence microbes in an obvious mode.In addition, a higher concentration of heavy metals did not always reduce microbial activities.It had been found that certain microbial species, asα-subdivision of Proteobacteria and the genus Burkholderia includes species may even prosperous under heavy metal polluted conditions,so the role of heavy metals should be carefully considered according to practical situations.Microbial indices could be affected by various environmental factors and the function of microbes to monitor slight processing metal contaminations was limited. Just as in Zibo deposit, in this case study, pH showed more influence to microbial communities and among those indices Cmic appeared to be the most sensitive parameter. There were congenitally deficient in BIOLOG methods and explanations of the data should be careful,with fully consideration of the situation in the study area.Development of new methods and more broad data collection should be necessary. We regard the dominate factor of influence here was the pH values, for it had the most close relationship with many parameters. Significant negative correlation was found between pH and PC3 of soluble metals, which had the largest loading on Cu. That is because lower pH could be helpful to solubilize Cu. In fact, soluble metal contents were easier show higher value as pH declined for the lower pH would increase the availability of heavy metal. A relatively higher pH value could also promote microbial activities,that was why significant positive correlations were found between pH value and microbial carbon and culturable aerobic heterotrophic bacteria numbers.Also microbial parameters could hardly reflect metal contaminations on the whole, their differences of sensitivities still could be observed. In our study, the incubation curve of AWCD calculated from BIOLOG data did not separate well according to heavy metal contents. In further analysis, the fourth and fifth components were influenced by metal components significantly.The fourth component had high loading on D-xylose, Pyruvic acid methyl ester and Glycogen; the fifth component had high loading onβ-Methyl-D-glucoside, N-acetyl-D-glucosamine andα-Cyclodextrn. That proved an uneven importance of the carbon source utilization.However, the relation between carbon source utilization and heavy metals changed when other soil properties were included as control variables. That suggests the influence to microbes of soil were complicated and the interpretation should be careful. On the whole, BIOLOG methods were incapable to reveal subtle changes of environment. Cmic showed significant correlations with many environmental parameters and positive correlations were found between Cmic and metal PCs. It may be regarded as also Cmic acted sensitive to environment but the interpretation of it must be careful. Culturable microbes can be used as a complement and reference to the uncultured methods.The application of microbial parameters as complemental environmental quality indices showed significant results.In this case,we used culturable microbes to replace BIOLOG indices in the ordination analysis to get another aspect of description.We found the modification of Nemerow index shown different trends compared to Zibo deposit for the samples.While in Zibo deposit Nemerow index became more different in adjacent samples,Zhaoyuan samples near each other turned to be more similar. We deemed it was caused by the relative consistence in farm land so microbes in the same area may be liable to have similar activities.After the calculation of BIO index,we found totally different trends based on total and available metal contents, as the same in the first study.The reason came from the definition and extraction methods of available metals. Metals soluble in certain liquid were called available form but it is hard to find out how available they are to organisms. Further more, driven by the difference of different extraction method, available contents were for sure would have no determinate relationship to total metal concentrations, let along linear relationship. That is why available metal contents showed different environmental quality indices to total metal contents. Of course, the applications of the concept of "available concentration" were still helpful for they are after all more close to the survival of organisms. We can use BIO index to define their environmental influences and make careful survey of to what extent they are available.Based on the two cases, we believe the BIO index give more thoughts to biological conditions and is valid in reflect environmental safety. The theory is biological indices are honor to environmental influence and their behaviors is the results of different environmental portrays. In a simple way we integrated the most reliable information to calculate environmental quality index,and we deem it is a significative indicator.The biological informations integrated in environmental quality index were mainly based on ordination method in this study. However, descriptions of biological patterns without spatial consideration were somehow incomplete.The applications of spatial analysis methods are becoming hot of the press in microbial ecology studies.However, due to subject barriers and the minuteness of microbes,spatial concepts did not receive adequate attention in China.So we made a summary of spatial methods in microbial ecology studies.Of course,due to the research technique limitations and the special characteristic of microbes, most studies are only at the exploratory stage while the relative methods are also developing. This chapter focuses on the intents of spatial analysis,combined with the purpose of microbial ecological studies, and gives a presentation of the submission of spatial methods in the microbial ecology. We introduced the descriptions of spatial autocorrelation in microbial ecology studies, including Moran'I and Geary's c, Mantel test and the use of variogram analysis. Kriging was refereed as a tool to predict microbial patterns and the scale in microbial studies were discussed too. Our work will be helpful in the understanding of applying spatial method in microbial ecology and give rise to the attention of this kind of method. Certainly, biological information with spatial consideration will be helpful to give references to environmental quality indices.