Studies On Fermentation For Acetone-butanol-ethanol Using Cane Molasses By Clostridium Beijerinckii DSM6422

As a method of liquid fuel and industrial raw materials manufacturing by biomass conversion, acetone-butanol-ethanol fermentation is paid attention again in reality. Butanol as a kind of important chemical and biofuel, its biological production method is becoming focused world widely. What the critical thing is, to reduce the cost of product butanol in a biomass conversion way, in order to get competitive advantage by comparison from traditional chemical synthetic way.Based on Chinese agricultural plant structure, materials most commonly used as substrate of acetone butanol traditional fermentation are mainly consist of corn, dry matter, grain and other starchy materials, not only used as daily rations in a normal way, but also for livestock feed and industrial use of grain.The key point of bio-butanol industry lies in efficiency usage of non-food substrate. Solvent fermentation of lignocelluloses, which needs to achieve industrial production level is also critical if food supplies of country’is taken into consideration.The advantages of producing acetone-butanol-ethanol in biomass conversion way by using cheap raw materials of non-grain molasses are, lower cost and continuousation, which compares to solvent fermentation by using lignocelluloses. Investment could be slightly increased based on ethanol production in molasses fermentation process, as strain changing and existing related condition are used to product acetone-butanol-ethanol。Most of identified carbon source fermentation strains belong to Clostridium beijerinckii. Primary study has been processed by using Clostridium beijerinckii DSM6422, which was purchased from Deutsche Sammlung von Mikroorganismen und Zellkulturen (DSMZ).This study began from ingredient of medium and incubate condition. Observations of this study includes initial carbon resource concentration, material pretreatment, additional nitrogen resource, optimized nitrogen resource concentration, amount of additional CaCO3, seed age、 inoculation amount, temperature and pH value.Study showed that pretreatment was needed by using cane molasses as basic material, otherwise strong influences may occur because of colloids, insoluble solid particles inside of cane molasses. H2SO4was selected in this case. Additional nitrogen resource was needed since original nitrogen from cane molasses itself is not enough. Based on a view of cost, cheapter (NH4)2SO4was selected, which concentration reached2g/L.pH influences were observed from fermentation when strain was growth. The condition was changed by adding additional CaCO3up to10g/L as buffered material.This study also showed that the optimized fermentation condition was22hrs as inoculation time,6%as inoculation amount,30oC as temperature and7.0as pH value.After96h fermentation in an optimized way, butanol concentration in broth was in10.32g/L, as well as the concentration of total solvent has increased to three times as ever before. Carbon concentration decreased from38.82g/L to6.82g/L, which means its utilization has increased by53.3%.In a5-L bio-reactor, the total carbon resource was60g/L at the very beginning. After96hrs incubation, the concentration of total solvent was16.18g/L, included10.08g/L of butanol production. The total yield concentration was30.2%and carbon resource utilization was89.3%. Evidences from this study showed that results from bioreactor and incubation flask matched with each other very well.This study in5-L bioreactor showed that, the optimized fermentation period has decreased by24hrs from normal one to only72h, as improvement of equipment utilization and cost saving for production with efficiency.