A novel acid-producing fungus isolated from bauxite residue: the potential to reduce the alkalinity

作者：Liao, Jiaxin; Jiang, Jun; Xue, Shengguo^*; Cheng Qingyu; Hao Wu; Manikandan, Rajendran; Hartley, William; Huang, Longbin

来源：Geomicrobiology Journal, 2018, 35(10): 840-847.

DOI：10.1080/01490451.2018.1479807

• Bauxite residues
• alkali-tolerant fungus
• acid production
• Penicillium oxalate
• soil formation

Globally, bauxite residue is creating extensive environmental problems. Nevertheless, there are numerous functional microorganisms that exist in this extreme environment, and fungus has an essential role in the pedogenesis of bauxite residue. This study describes a microbial method to reduce the alkalinity of bauxite residue through the actions of a functional fungus to produce acidic substances. Bauxite residue samples were screened for fungal activity, and fungal tolerance was assessed using saline and alkaline media of varying concentrations, using aniline blue-PDA medium to evaluate acid production. A tolerant fungus with the ability to produce acidic substances was selected and named EEEL01 (Environmental Ecological Engineering Laboratory No. 01). Further morphological and molecular characterization identified this fungus as Penicillium oxalicum. Factors including pH, NaCl concentration, carbon and nitrogen sources were used to test the efficiency of acid production by the fungus. Based on optimal growth conditions, bauxite residue inoculated with EEEL01 reduced pH from 10.26 to 6.48 over 11 days. These results suggest that EEEL01 could effectively grow and release organic acids under extreme alkaline and saline conditions, which provide the potential for remediation.

• 出版日期2018-11-26
• 单位中南大学