DONG Cui-ling, LIAN Bin
Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing 210023, China

Abstract: This study compared the similarities and differences of biotite bio-weathering by bacteria and fungi using Bacillus mucilaginosus and Aspergillus niger as examples and provided experimental evidence for the weathering mechanism of different microorganism species. Surface morphology of biotite, ions concentrations in cultures and CA activities were detected by ICP-OES, SEM and a specific method for CA activity determination after been cultured in nitrogen-containing or czapek's media for 5 days. It was observed that B. mucilginsus and biotite adhered tightly to form bacterial-mineral complexes on some sticky substances, such as polysaccharides, while the fungal hyphae wrapped biotite to form fungus-mineral aggregates. The overall concentrations of released ions in the fungal culture were higher than those in the bacterial culture, especially, concentrations of Al3+, Fe3+ and K+ were 17, 30 and 3 mg/L higher, respectively. Both of acidic substance amount and CA activity in the fungal culture were significantly higher than those in the bacterial culture. Therefore, we confirmed that the mineral weathering capacity of A. niger is relatively higher than that of B. mucilginsus.

Keywords: Bacillus mucilaginosus Aspergillus niger biotite weathering mechanism

*Corresponding Author, E-Mail: bin2368@vip.163.com

Bulletin of Mineralogy, Petrology and Geochemistry Vol. 33, No.6, 2014, page 772-777