Biodiversity, abundance, and activity of nitrogen-fixing bacteria during primary succession on a copper mine tailings

Abstract

Microorganisms are important in soil development, inputs and biogeochemical cycling of nutrients and organic matter during early stages of ecosystem development, but little is known about their diversity, distribution, and function in relation to the chemical and physical changes associated with the progress of succession. In this study, we characterized the community structure and activity of nitrogen-fixing microbes during primary succession on a copper tailings. Terminal fragment length polymorphism (T-RFLP) and clone sequencing of nifH genes indicated that different N(2) -fixing communities developed under primary succession. Phylogenetic analysis revealed a diversity of nifH sequences that were mostly novel, and many of these could be assigned to the taxonomic divisions Proteobacteria, Cyanobacteria, and Firmicutes. Members of the Cyanobacteria, mostly affiliated with Nostocales or not closely related to any known organisms, were detected exclusively in the biological soil crusts and represented a substantial fraction of the respective diazotrophic communities. Quantitative PCR (and statistical analyses) revealed that, overall, copy number of nifH sequences increased with progressing succession and correlated with changes in physiochemical properties (including elementary elements such as carbon and nitrogen) and the recorded nitrogenase activities of the tailings. Our study provides an initial insight into the biodiversity and community structure evolution of N(2) -fixing microorganisms in ecological succession of mine tailings.

Dynamics in leachate chemistry of Cu-Au tailings in response to biochar and woodchip amendments: a column leaching study

“…Ca/Mg carbonate minerals are also common gangue materials in mine tailings, with dissolution rates 3-order-of-magnitude faster than sulphide oxidation [36]. Consequently, in sulphidic metal mine tailings abundant in carbonates, pH can be well buffered as shown in this ( Figure 2) and previous studies [20,[37][38][39], resulting in extreme salinity inevitably. This mechanism controlling tailing hydrogeochemistry has been well demonstrated elsewhere [35,36] and again reflected in this study.…”

“…Nitrite is normally low in oxic layer and may only accumulate where oxygen is depleted by organic matter decomposition [48] or microscale consolidation and nitrification is depressed [49]. Previous studies have revealed an unexpected diversity of microbes present in Cu mine tailings [50,51], and many of them are able to fix gaseous N [39] into tailing N pool. Reasonably, N-cycling microorganisms may have played important roles in controlling the N dynamics in the tailing leachate.…”

High diversity of nitrogen-fixing bacteria in the upper reaches of the Heihe River, northwestern China

“…(2), where n i is number of clones of the i-th OTU, and p i indicates the proportion of clones of the i-th OTU in the total clone library of the sample (Duc et al, 2009). (Huang et al, 2011) (1)…”

“…In order to cluster or separate the samples based on the characteristics of the nitrogen-fixing bacterial communities, hierarchical cluster analyses were performed using the SPSS statistical package (version 16.0, SPSS Inc., Chicago, IL, USA) with the average-linkage-between-groups methods (Huang et al, 2011;Nonnoi et al, 2012).…”

Can graminoids used for mine tailings revegetation improve substrate structure?

“…Mine wastes are transported from the mine plant (usually pumped) as aqueous slurries and deposited into tailings storage facilities that generally cover large surface areas that are prone to erosion. Mine tailings are prone to several concomitant stresses: lack of water, nutrients, and air; extreme temperatures; wind exposure; and salinity due to chemical addition during the ore processing (Huang et al 2011;Parraga-Aguado et al 2013). …”