초록
Propionate is an important chemical widely applied in industry and its production<I>via</I>fermentation is economic. Many literature studies have reported propionate was produced with pure culture fermentation. However, the following by-products production in pure culture fermentation limits its application. In this work, a high purity of propionate production from glucose in mixed culture fermentation (MCF) under the condition of high ammonium concentration was first investigated. The bottle tests showed that up to 1.4 g L<SUP>−1</SUP>of ammonium severely inhibited propionate degradation but had little effect on acetate degradation. In fed-batch experiments, propionate was produced with more than 16 g L<SUP>−1</SUP>concentration and the purity reached more than 90% of liquid metabolites. Under the sequential batch operation, the propionate yield was 0.37-0.47 g COD per g COD and propionate accounted for 98% of liquid metabolites. The microbial community analysis revealed that Betaproteobacteria and Deltaproteobacteria, the propionate-utilizing microbes, were decreased from 7.94% to 3.72% at high ammonium levels, while<I>Methanosaeta</I>that mainly appeared at high ammonium concentration in the literature was the dominating aceticlastic methanogen. Hence, this work demonstrates a great potential application of MCF to effectively produce high purity propionate..