Stimulatory Effect Of Phanerochaete Chryso Sporium On Bioethanol Production By Water Hyacinth

Using water hyacinth as raw material to produce bioethanol can not only solve the pollution problem,but also can alleviate energy crisis,thus realizing the resource utilization of solid waste.Because of the complex structure of lignocellulose,pretreatment is an indispensable step in the process of bioethanol production.Phanerochaete Chrysosporium was selected as effective microorganism for lignocellulose pretreatment in this article.The influence of single microorganism pretreatment,chemical pretreatment combined with microorganism pretreatment on bioethanol production was investigated,and the optimum conditions for pretreatment was analyzed.Firstly,the optimal pretreatment conditions of single microorganism pretreatment,including inoculation amount,degradation time and degradation temperature,were investigated by single factor experiment.The main factors were further optimized by response surface experiment.The results showed that the optimal condition for single microorganism pretreatment was 30.09? for 58.23 h when 5.09 rings inoculum was added.The reducing sugars could achieve 208.57 mg·g^-1 at this condition.By using SPSS analysis,the influence degree of the three factors on reducing sugar production was degradation temperature>degradation time>inoculum.Secondly,the chemical pretreatment combined with microbial pretreatment on reducing sugars production was studied.Three main factors,including inoculum amount,temperature and acid/alkali concentration were selected to optimize the pretreatment conditions by orthogonal experiment.The results showed that the optimal pretreatment conditionfordilute acid combined with microorganism pretreatment 100? when 4 ringsinoculum and 1%dilute acid was added.The optimum condition for dilute alkali combined microorganism pretreatment were 100?when 4 ringsinoculum and 4%dilute alkaline was added.The reducing sugars could achieve 430.66 mg·g^-1 and 402.10 mg·g^-1 at these two optimum conditions,respectively.Thirdly,the components of water hyacinth were analyzed after degradation.It was shown that the content of cellulose increased obviously,and the hemicellulose and lignin content decreased.The structure and morphology change of water hyacinth were determined by SEM and FTIR,which indicated that the organs of water hyacinth were seriously broken and functional group bonds were obviously ruptured.The carbonyl,which was connected by lignin and aromatic nucleus,was highest breakage,which showed that lignin contents was sufficiently destroyed.Finally,the fermentation process for bioethanol production by water hyacinth were selected.The results showed that in the process of SHF?Separate Hydrolysis and Fermentation?,the maximum bioethanol yield could achievel.4g·g^-1 when 6mL yeast suspension was addedat 24h.In the process of SSF?Simultaneous Saccharification and Fermentation?,the maximum ethanol yield was 1.45g·g^-1 when 6mL yeast suspension was addedat 72h.Because of the advantage of simpler operation process,less degradation time,smaller space occupation and higher ethanol production,SSF was chosen as the better fermentation process for bioethanol production.