Selecting Of Molasses Waste Resource Strains And Optimization On Fermentation Conditons

China is a large sugar producing country,pollution and waste problems consist in the sugar industry,molasses are the main waste in the production process,the energy of molasses is rich,containing a large number of unused components,and direct discharge rise a greater impact on the environment,so to treat molasses by microorganism,can make full use of resources to produce all kinds of valuable products,turning waste into treasure,not only can solve the effects of molasses on the environment,but also can bring a certain economic value.In this study,molasses was used as raw material to construct molasses microbial flora to produce feed of cell protein,which can effectively reduce the concentration of molasses COD and degrade pectin in molasses waste.According to the ability of producting cell protein and degradating pectin,chose 4 laboratory preservated strains;through further screening culture medium of molasses,determined Aspergillus niger and Saccharomyces cerevisiae to take the fermentation experiment,the cells protein production of Aspergillus niger is 1.2g/L(15%),0.9g/L(11%)is showed by Saccharomyces cerevisiae,the experiments showed that the removal rate of COD was positively correlated with cell protein production effect.With the construction of Aspergillus niger and Saccharomyces cerevisiae mixed fermentation strains,through the single factor experiment,found that mixed fermentation was better than single strain fermentation,determined the optimum range of the fermentation conditions,the yield of cell protein was at the range of1.40g-1.45g/L(about 17.8%).According to the results of single factor experiments,chose four factors of temperature,inoculation amount,strain ratio,liquid volume to take orthogonal optimization,experimental results show that the size order of the impacted factors is: strains ratio > volume of liquid> temperature > inoculation amount,the optimum fermentation conditions of the theory of production cell protein: temperature 28?,inoculation amount 1.5%,strains ratio 4/1,volume of liquid 50 m L,through the verification experiment,the yield under this condition is 1.53g/L cell protein(19.1%),higher than all the orthogonal experiment groups;on the basis of this,we take the the optimization with fine regulation by N,P regulation,after adding fermentation effect is improved;in addition to this,we added a certain proportion of straw,the experimental results are higher than that before optimization,with the combination of the adjustment and optimization,while adding N,P and N,P,straw group were higher than before the combination,the yield of cell protein was up to1.66 g/L(20.7%),proved that the optimization of fermentation could raise the yieldof cell protein by fine fermentation regulation and substrate optimization.According to the pectin degradation ability and the experiment of strain ratio,constructed strains of Bacillus subtilis and Aspergillus nigerr.The experimental results show that when the strain ratio is 1:2,pectin degradation rate reached to91.4%,is the best degradation effect,with the analysis important components of before and after pectin degradation,found that the higher the content of galacturonic acid got a increase of 4.6%,while the arabia sugar and rhamnose component did not get the corresponding enrichment.This topic through the production of cell protein and pectin degradation,this two directions tentatively constructed the molasses resource strains,provides a reference for the production process of waste molasses,which laid a foundation for further research,the microorganisms in molasses waste utilization areas plays an increasingly important role.