Production of bioflocculant using immobilized bioflocculant-producing bacteria

To reduce fermentation costs and achieve continuous fermentation of bio-flocculant, the immobilized fermentation to produce bioflocculant was used. The performances of the carriers including activated carbon, pllyurethane foam and mycelial pellets were contrasted by comparing the carrier stability, bio-flocculant production and bio-flocculant activity. The solid-liquid ratio of activated carbon and mycelial pellets were optimized. The results show that the activated carbon, polyurethane foam and mycelial pellets could adsorb bioflocculant-producing bacteria F+ and retain high flocculanting activity for long time. The yields of activated carbon and mycelial pellets were higher than that of polyurethane foam. The adsorption rate of mycelial pellets in 24 h was higher than that of granular activated carbon. Under the optimized conditions (solid-liquid ratio 1.0 g/L; the fermentation time 24 h), the crude bio-flocculant yield of immobilized fermentation by mycelial pellets (2.234 g/L) increased 14%. The shake flask experiments show that the three carriers could produce bioflocculant more than 15 batches. The solid-liquid ration was optimized as 1.0 g/L by considering the flocculation rate and cost.