Towards Sulfide Resistant Bioproduction; Understanding Sulfide Toxicity During Homoacetogenic Fermentation

A series of toxicity experiments were conducted in serum flasks inoculated with a mixed homoacetogenic culture and added total dissolved sulfide (TDS) concentrations between 0 and 5 mM. Inhibition was evaluated based on acetate production by the microbial community and bacterial growth. The effect of sulfide and pH on the microbial community diversity was examined based on 16s rRNA Illumina sequencing analysis. Sulfide toxicity was assessed at pH 5, 6 and 7 to possibly make a distinction between the effect of H2S and HS-. Increasing TDS concentrations had an inhibitory effect on both acetate and biomass production.