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高效木薯渣分解复合菌群RXS的构建及其发酵特性研究 总被引:1,自引:0,他引:1
从富含腐烂纤维质的环境中取样,通过以木薯渣及滤纸为碳源的蛋白胨纤维素培养基不断地富集培养,构建了一组高效稳定的纤维质分解复合菌群.考察了该复合菌群对不同纤维质底物的分解性能及其在木薯渣水解过程中主要参数的变化.研究发现该复合菌群对滤纸、脱脂棉、微晶纤维素、麦秸秆和木薯渣等原料均能够进行有效的降解.在该复合菌群应用于木薯渣的水解过程中,监测发现纤维素酶、半纤维素酶、果胶酶等关键酶的酶活力分别在第2~3 d达到最大值34.4、90.5和15.8U;经过10 d的发酵后,木薯渣中的纤维素、半纤维素及木质素分别降解了79.8%、85.9%和19.4%,且木薯渣的失重高达61.5%;此外,代谢产物主要是乙酸、丁酸、己酸和甘油;而溶解性COD、总糖和总挥发酸的变化表明第2 d时木薯渣的水解率最高.上述结果表明,该复合菌群能够有效地水解木薯燃料酒精生产过程中的废弃物木薯渣,并有望用于木薯渣高效沼气发酵的前处理中. 相似文献
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北方泥炭地是全球重要的碳汇,也是全球变暖最为敏感的区域之一.然而,由于泥炭地表层和亚表层泥炭土碳排放过程对全球变暖的响应过程及机制仍存在一定争议,目前对全球变暖背景下泥炭地碳排放的认识仍存在一定不足.本研究于2019年8月在大兴安岭满归泥炭地采集表层(0~10 cm)和亚表层(15~30 cm)泥炭土进行室内增温模拟有氧培养,测定其矿化速率、有机质性质和水解酶活性.结果表明,表层泥炭土矿化速率在5、15、25℃下培养时((142.8±66.9)~(545.3±30.6)、(575.0±62.1)~(1843.0±547.4)、(888.4±123.9)~(3646.7±167.9)μg·g-1·d-1)均高于亚表层((113.0±41.5)~(367.1±64.1)、(357.4±52.3)~(1122.1±218.8)、(697.1±38.1)~(2336.4±150.6)μg·g-1·d-1),但表层和亚表层矿化作用的温度敏感性不具有显著差异;培养过程中,表层与亚表层泥炭土β-1,4-N-乙酰葡... 相似文献
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Review on the use of enzymes for the detection of organochlorine, organophosphate and carbamate pesticides in the environment 总被引:5,自引:0,他引:5
Pesticides are released intentionally into the environment and, through various processes, contaminate the environment. Three of the main classes of pesticides that pose a serious problem are organochlorines, organophosphates and carbamates. While pesticides are associated with many health effects, there is a lack of monitoring data on these contaminants. Traditional chromatographic methods are effective for the analysis of pesticides in the environment, but have limitations and prevent adequate monitoring. Enzymatic methods have been promoted for many years as an alternative method of detection of these pesticides. The main enzymes that have been utilised in this regard have been acetylcholinesterase, butyrylcholinesterase, alkaline phosphatase, organophosphorus hydrolase and tyrosinase. The enzymatic methods are based on the activation or inhibition of the enzyme by a pesticide which is proportional to the concentration of the pesticide. Research on enzymatic methods of detection, as well as some of the problems and challenges associated with these methods, is extensively discussed in this review. These methods can serve as a tool for screening large samples which can be followed up with the more traditional chromatographic methods of analysis. 相似文献
4.
Sakie Miyazaki Kazuhei Takahashi Mari Shiraki Terumi Saito Yoko Tezuka Ken-ichi Kasuya 《Journal of Polymers and the Environment》2000,8(4):175-182
A poly(3-hydroxybutyrate) (PHB) depolymerase was purified from a fungus, Penicillium funiculosum (IFO6345), with phenyl-Toyopearl and its properties were compared with those of other PHB depolymerases. The molecular mass of the purified enzyme was estimated at about 33 kDa by sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis. The pH optimum and pI were 6.5 and 6.5, respectively. The purified protein showed affinity to Con A-Sepharose, indicating that it is a glycoprotein. Diisopropylfluorophosphate and dithiothreitol inhibited the depolymerase activity completely. The N-terminal amino acid sequence of the purified enzyme was TALPAFNVNPNSVSVSGLSSGGYMAAQL, which contained a lipase box sequence. This purified enzyme is one of the extracellular PHB depolymerase which belong to serine esterase. The purified enzyme showed relatively strong hydrolytic activity against 3-hydroxybutyrate oligomers compared with its PHB-degrading activity. PHB-binding experiments showed that P. funiculosum depolymerase has the weakest affinity for PHB of all the depolymerases examined. 相似文献
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针对醋糟中木质纤维素利用效率低的问题,通过接种瘤胃微生物可强化木质纤维素水解.采用逐步提升体系有机负荷的方式,考察瘤胃微生物生物强化对醋糟厌氧消化性能的提升效果,并运用绝对定量实时聚合酶链锁反应(Q-PCR)技术探究其微生物学强化机制.结果表明:长期连续运行成功塑造了高效的木质纤维素瘤胃强化体系.该体系的最高有机负荷达8.90 g/(L·d)(以VS计),是强化前的1.53倍,该有机负荷下半纤维素和纤维素降解率分别达73.9%和40.1%,单位质量底物沼气和甲烷产量相应地分别达到451和261 mL/g(以VS计),半纤维素和纤维素较高的降解率是该体系维持高产气性能的主要原因.生物相机制研究表明,瘤胃微生物强化体系中与木质纤维素水解密切相关的GH5(糖苷水解酶家族5)水解菌逐步富集,其基因拷贝数从初始的964×1010 copies/g升至最高有机负荷下的6.83×1011 copies/g,这是底物在高有机负荷下仍能被高效生物转化的根本原因.研究显示,瘤胃微生物的介入可有效强化体系底物的降解能力,促进醋糟产甲烷性能的提升. 相似文献
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Thomas M. Scherer R. Clinton Fuller Robert W. Lenz Steve Goodwin 《Journal of Polymers and the Environment》1999,7(3):117-125
A strain of Aspergillus fumigatus, which was observed to rapidly degrade poly-3-hydroxybutyrate (PHB) in a leaf compost, was found to secrete an extracellular hydrolase when grown on PHB as the sole carbon source. Isolation and characterization of the PHB hydrolase (depolymerase) from this fungus revealed that the enzyme had a molecular weight of 57 kDa, an isoelectric point of 7.2, and a PHB hydrolysis activity maxima which occurred at 70°C and pH 8.0. Affinity labeling experiments suggested that this fungal hydrolase is a type of serine esterase. The cyclic trimers of 3-hydroxybutyrate were found to reversibly inhibit the enzymes. 相似文献
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Substituted urea compounds are well-known as potent inhibitors of juvenile hormone epoxide hydrolase (JHEH) of the tobacco hornworm Manduca sexta. Docking simulations of 47 derivatives inside JHEH were performed to gain insight into the structural characteristics of these complexes. The obtained orientations show a strong similitude with the observed in the known X-ray crystal structures of human soluble epoxide hydrolase (sEH) complexed with dialkylurea inhibitors. In addition, the predicted inhibitor concentration (IC50) of the above-mentioned compounds as JHEH inhibitors were obtained by a quantitative structure-activity relationship (QSAR) method by using comparative molecular field analysis (CoMFA) applied to aligned dataset. The best models included steric and electrostatic fields and had adequate predictive abilities. In addition, these models were used to predict the activity of an external test set of compounds that was not used for building the model. Furthermore, plots of the CoMFA fields allowed conclusions to be drawn for the choice of suitable inhibitors. 相似文献
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淀粉酶前处理应用于猪粪沼气发酵的研究 总被引:1,自引:0,他引:1
沼气发酵经历了水解、产氢产乙酸和产甲烷三个阶段,若发酵原料是一些小分子水溶性物质,则产甲烷阶段将是整个过程的限制阶段,若发酵原料为大分子复杂有机物,则第一阶段便成了限制阶段。在实际应用中,沼气发酵的原料通常为复杂的大分子有机物,因此原料的水解反应速度决定了整个沼气发酵过程的速度。为消除水解阶段的限制,提高沼气发酵的效率,本实验尝试采用水解酶前处理技术,在猪粪沼气发酵前,先用淀粉酶预处理。实验结果表明经淀粉酶处理后,猪粪的TS和VS降解率,累积产气量,原料产气潜力,最大容积产气率,与对照组相比有明显的提高,其中经α-淀粉酶和γ-淀粉酶共同处理的TS和VS降解率分别提高了10.84%和11.11%、累积产气量提高了14.71%、原料产气潜力提高了14.7%、最大容积产气率提高了19.79%。 相似文献
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