Long-term enrichment of anaerobic propionate-oxidizing consortia: Syntrophic culture development and growth optimization

Propionate is a quantitatively important methanogenic intermediate in anaerobic digesters and only limited number of microbes can utilize it under syntrophic association with methanogens. The propionate oxidizing bacterias are known to be slow growers due the low energy yield. Thus, get accumulated frequently negatively affect digester performance. In this study, degrading consortia from four different seeding sources were enriched sequential bath mode two phases; first adaption phase 1 g/L concentration later, high-strength 3 g/L. From 16s rRNA gene based metagenomics analysis former phase, microbial groups, Syntrophaceae, Syntrophomonadaceae, Methanobacterium Methanosaeta found dominant complete degradation propionate. substrate accelerated shifts observed at significant decrease Syntrophaceae up 26.9 %. Using Response Surface Methodology, pH 6.8–6.9 temperature 34.5–34.9 °C optimum growth conditions for culture. Observed results could useful improve efficiencies obtained culture used recover propionate-accumulated by bio-augmentation.