Quantification of Biomass Production and Organic Acid Production for Three Fungal Candidates

A. Lobos

Author address: 

Univ. of South Florida, Tampa, FL


An environmentally friendly fungal bioleaching process with organic acids produced by Aspergillus niger, Penicillium chrysogenum and Penicillium simplicissimum will be investigated as an alternative leaching method for the recovery of lithium/cobalt from spent rechargeable Liion batteries. The first approach for this plan is to quantify fungal growth by recording the biomass production and measuring pH changes on two different mediums; high performance liquid chromatography will be used to quantify organic acid production for the three fungal species over 10 days to determine the best candidate for fungal bioleaching of lithium and cobalt from spent lithium-ion batteries. The three fungal candidates were cultured in sabouraud dextrose broth and czapek dox broth for 10 days at 30°C while shaking at 125rpm; samples were collected in triplicates every 24 hours and processed to determine dry biomass production, pH of medium and organic acid production. Preliminary results with fungi in sabouraud dextrose broth after 10 days of growth: pH of medium was measured before inoculation of fungi, mean pH (5.37 + 0.042); Aspergillus niger dry weight biomass mean (3.35 g/L + 2.254 g/L), mean pH (3.57 + 0.899), mean concentration of oxalic acid (51.104 mM + 2.187 mM); Penicillium chrysogenum dry weight biomass mean (1.862 g/L + 0.905 g/L), mean pH (4.21+ 0.057), mean concentration of oxalic acid (11.16 mM + 3.016 mM); Penicillium simplicissimum dry weight biomass mean (3.106 g/L + 1.505 g/L), mean pH (4.89 + 0.053), mean concentration of oxalic acid (5.26 mM + 2.568 mM). Preliminary results indicate that Aspergillus niger will be the top candidate due to high production of oxalic acid. The data collected in this study will expand knowledge on the process for organic acid production in three fungal species and help select the top candidate for fungal bioleaching. After quantification of organic acid production and fungal growth is complete, metal tolerance tests will then be done to determine the toxicity of lithium and cobalt to each fungal candidate; bioleaching experiments will then be conducted to recover lithium and cobalt from spent rechargeable lithium-ion batteries.

abstract No: 


Full conference title: 

ASM Microbe 2016
    • ASM microbe 1st (2016)