【作者】 齐亚林；

【导师】 龙敏南；

【作者基本信息】 厦门大学 ， 微生物学， 2007， 硕士

【摘要】 利用微生物以自然界中极为丰富的纤维素类秸秆为底物进行生物制氢,对开发新能源、降低环境污染、实现经济的可持续发展战略有重要意义。以产酸克雷伯氏菌(Klebsiella oxytoca)HP1为产氢菌株,以稻草粉为产氢底物,进行同步糖化发酵(Simultaneous Saccharification and Fermentation,SSF)产氢。对影响同步糖化发酵产氢的单因子进行试验,选取对产氢影响较大的因子:温度、pH、纤维素酶用量进行L9(33)正交试验。结果表明同步糖化发酵产氢的最佳条件为:温度40℃,pH 6.5,纤维素酶用量为20 FPAU/g稻草粉,摇床转速100 r/min,发酵时间42 h。在该条件下的最大氢产量为110.6 mL/g稻草粉。进行了10 L放大发酵产氢试验,最大氢产量为122.3 mL/g稻草粉。与分步糖化发酵(Separate Hydrolysis and Fermentation ,SHF)产氢相比,氢产量提高34.4%。研究表明利用同步糖化发酵工艺可提高生物制氢的产量。对产酸克雷伯氏菌( Klebsiella oxytoca ) HP1和荚膜红假单胞菌(Rhodopseudomona capsulata)CN1混合发酵产氢进行了研究。实验对影响混合发酵产氢的因素进行了研究,结果表明:混合发酵最适光照强度为4000 lux,荚膜红假单胞菌(Rhodopseudomona capsulata)CN1最佳接种量为20%,最适起始pH为7.5,最适氮源为蛋白胨(3 g/L),谷氨酸钠次之。加入氨盐会抑制放氢,但可以缩短光合产氢的停滞期。产氢实验须在厌氧条件下进行,即使浓度为3%的氧浓度也会影响放氢。在最适条件下,混合发酵氢产率为4.0 mol H2/mol (CH20)6,氢转化率为66.7%。以同步糖化发酵制氢的废液为底物进行混合发酵制氢。同步糖化发酵制氢的废液中含有机酸类(丁酸2.55 g/L,乙酸0.51 g/L)和残余糖类(3.1 g/L)可以被荚膜红假单胞菌(Rhodopseudomona capsulata)CN1和产酸克雷伯氏菌(Klebsiella oxytoca)HP1利用。氢产量为920mLH2/L培养基(同步糖化发酵制氢的废液)。因此,以稻草粉为底物,经过同步糖化发酵制氢和混合发酵制氢后稻草粉的最终产氢率为140.7 mLH2/g稻草粉。生物质发酵制氢废水含有大量的产酸克雷伯氏菌(Klebsiella oxytoca)HP1和荚膜红假单胞菌(Rhodopseudomona capsulata)CN1菌体。实验对壳聚糖作为絮凝剂处理发酵制氢废水以进行菌体蛋白的收集和废水处理进行了研究,考察了pH值、壳聚糖用量和絮凝温度等对絮凝效果的影响,结果显示:在pH4.5,壳聚糖用量60 mg/L,絮凝温度40℃时,除菌率和COD去除率分别达到92.1%,40%,并改善了过滤效果,在与絮凝剂130的复合絮凝试验,除菌率可以达到94.1%。更多还原

【Abstract】 Biomass can be degraded by microbe into sugar which can subsequently be converted into energy source such as hydrogen. Such a process is significant when applied to put off energy source crisis, debate environmental pollution and realize the strategy of sustainable economy.Hydrogen production from rice straw by simultaneous saccharification and fermentation (SSF) was studied using the Klebsiella oxytoca HP1 in this report. The experiments of batch ferment hydrogen production were carried out in 600-mL serum bottles. Single factor and orthogonal experiments showed that the optimal conditions for hydrogen production were: pH6.5, ferment temperature 40℃, cellulose dose 20 FPAU/g rice straw, shake rate 100r/min and ferment time 42 h. The maximum H2 production (110.6 mL/g rice straw) was obtained under the above conditions. The enlarge experiments were carried out in a 10- L bioreactor , a maximum H2 production of 122.3 mL/g rice straw was achieved. The H2 production increased by 34.4% compared with the separated hydrolysis and fermentation hydrogen production. This research indicated a perfect application of SSF in biohydrogen production from cellulose material.Hydrogen production by a mixed culture of R. capsulata CN1 and K. oxytoca HP1 was investigated. The experiments of batch ferment hydrogen production were carried out in 140-mL serum bottles which were filled with argon (Ar). The optimal conditions for hydrogen production were: initial pH 7.5, light intensity 4000lux, Rhodopseudomona capsulata CN 1 inculation volume 20%, 3g/L peptone as nitrogen resource and the sodium glutamate secondary. The stasis stage was evidently shortened when ammoniate were added as nitrogen source, but the yield of H2 production decreased. The anaerobic atmosphere is necessary for hydrogen production,even 3%oxygen can decrease the production of hydrogen. Under the optimal conditions the maximum H2 production was obtained as 4.0 mol H2/ mol (CH20)6 with a H2 yield of 66.7%.The liquid waste of SSF includes lots of organic acids(butyric acid 2.55 g/L, acetic acid 0.51 g/L)and suger (3.1 g/L) which can be used by Rh. capsulate CN1 and K. oxytoca HP1. Under the optimal conditions of mixed culture, the amount of hydrogen produced by the waste liquid of SSF was 920 mL H2/L. The total H2 production was 140.7 mLH2/g rice straw by the process of SSF and mixed culture。The liquid waste from biohyhrogen contains SCP(sinle cell protein) which can be recycled. In this research, chitosan has been used for receiving bacterium from wastewater .The result showed that the FR was 92.1%, and COD 40%, when the conditions were pH 4.5, chitosan dosage 60mg/l and 40℃. Under the optimal conditions the filtration speed of the flocculated sample was improved dramatically. When the chitosan and the flocculant of 130 were used together, the FR can reach 94.1% .更多还原