Accompanying effect of Bacillus licheniformis on Gluconobacter oxydans in mixed culture fermentation of vitamin C

To study the accompanying effect of Bacillus licheniformis on Gluconobacter oxydans in mixed culture fermentation of vitamin C,the growth profiles of B.licheniformis under single and mixed culture were investigated.With the growth of G.oxydans and the accumulation of 2-keto-L-gulonic acid (2-KLGA) being the index,the effect of the culture supernatants of B.licheniformis was analyzed.The influence of protease inhibitor on the accompanying activity was investigated.The results indicated that the active substance was produced and secreted when B.licheniformis was in log phase.So the culture supernatant of B.licheniformis had positive effect on the growth of G.oxydans and the accumulation of 2-KLGA.The activity of supernatant increased with prolonged culture period of B.licheniformis and reached peak at 18 h.Besides,the protease inhibitor (Phenylmethylsulfonyl fluoride,PMSF) didn′t show negative effect on the activity of supernatants.Proteases might have no relation with the accompanying activity of B.licheniformis.