固定化微生物细胞降解邻苯二甲酸二丁酯

The biodegradation of di-n-butyl phthalate （DBP） using immobilized microbial cells was carded out in an internal airlift loop reactor with ceramic honeycomb supports. A strain that is capable of degrading DBP was isolated from the activated sludge and identified as Bacillus sp. using 16S rDNA sequential analysis. Bacillus sp. could be rapidly attached onto the ceramic honeycomb supports. The immobilized cells could effectively degrade DBP in batch and continuous experiments. When the influent concentration of DBP was 50mg·L^-1, the effluent DBP reached less than lmg.L i with 6h hydraulic retention time （HRT） in continuous experiment. The immobilized microbial cells could grow and accumulate through the biodegradation of DBP, and the rate of degradation is accordingly increased. The possible pathway of DBP biodegradation using immobilized cells was tentatively proposed.     

固定化基因工程菌应用于水环境污染治理的研究进展

固定化细胞技术和基因工程技术在环境污染物治理领域是新兴技术。本文综述了近年来固定化细胞技术和基因工程技术在水环境污染治理中的研究及应用情况。通过固定化基因工程菌处理废水的一系列成功实验,表明了其在废水好氧反硝化等水环境污染治理中的广阔应用前景。     

新型细胞固定化载体强化白腐菌降解活性染料

为提高白腐真菌的产酶能力和后续对染料的降解效果,采用摇瓶试验研究新型细胞固定化载体——聚氨酯泡沫固定化白腐真菌后的锰过氧化物酶(MnP)产生情况以及后续对活性染料——活性艳红K-2BP的降解效果.结果显示,新型载体固定化培养白腐真菌的5d脱色率为95%,比悬浮培养7d的脱色率高15%.固定化培养产生的MnP酶活为936.61U/L,而悬浮培养的MnP仅为269.52U/L,并且酶活高峰期提前4d.另外,固定化培养体系中碳、氮源的消耗比悬浮培养快很多,而且固定化培养使得白腐真菌具有较高的H2O2产量.因此,新型细胞固定化载体强化白腐真菌降解活性染料的原因应归于这种培养体系碳、氮源的快速消耗而带来的MnP酶活的提高和高H2O2产量.     

固定化细胞技术在废水处理中的应用

固定化细胞技术在废水处理中的应用具有处理效率高、稳定性强、生物密度高、耐毒性、耐高负荷、产污泥量少等优点,但该技术仍处于试验阶段,要达到工业应用的水平还需要解决多种生物共生的固定化体系、固定化载体和固定化反应器,以及生物解析剂等问题。     

Preparation of regioisomers of structured TAG consisting of one mole of CLA and two moles of caprylic acid

TAG (MLM) with medium-chain FA (MCFA) at the 1,3-positions and long-chain FA (LCFA) at the 2-position, and TAG (LMM) with LCFA at the 1(3)-position and MCFA at 2,3(1)-positions are a pair of TAG regioisomers. Large-scale preparation of the two TAG regioisomers was attempted. A commercially available FFA mixture (FFA-CLA) containing 9-cis, 11-trans (9c, 11t)- and 10t,12c-CLA was selected as LCFA, and caprylic acid (C₈FA) was selected as MCFA. The MLM isomer was synthesized by acidolysis of acyglycerols (AG) containing two CLA isomers with C₈FA: A mixture of AG-CLA/C₈ FA (1∶10, mol/mol) and 4 wt% immobilized Rhizomucor miehei lipase was agitated at 30°C for 72 h. The ratio of MLM to total AG was 51.1 wt%. Meanwhile, LMM isomer was synthesized by acidolysis of tricaprylin with FFA-CLA: A mixture of tricaprylin/FFA-CLA (1∶2, mol/mol) and 4 wt% immobilized R. miehei lipase was agitated at 30°C for 24 h. The ratio of LMM to total AG was 51.8 wt%. MLM and LMM were purified from 1,968 and 813 g reaction mixtures by stepwise short-path distillation, respectively. Consequently, MLM was purified to 92.3% with 49.1% recovery, and LMM was purified to 93.2% with 52.3% recovery. Regiospecific analyses of MLM and LMM indicated that the 2-positions of MLM and LMM were 95.1 mol% LCFA and 98.3 mol% C₈ FA, respectively. The results showed that a process comprising lipase reaction and short-path distillation is effective for large-scale preparation of high-purity regiospecific TAG isomers.     

NY3菌固定化及生物膜处理含油废水的研究

利用嗜油菌NY3菌的固定化生物膜处理含油废水.用静态曝气法确定固定化时间、载体量、固定化液初始pH值.确定生物膜处理运行的HRT,并评估生物膜循环使用的可能性.结果表明,载体10 g/L,pH7.5~9.0,固定51 h,膜生物量达488.32 mg/g.其处理含油废水最佳HRT为6 h,出水油量在1.38~3.2 mg/L.废水处理后,将载体置于营养液中培养15 d,膜上NY3菌能将所吸附的油降解,使其恢复活性,并可循环利用.     

有机磷水解酶生物传感器载体固定化酶的研究

有机磷水解酶（OPH）传感器作为检测农产品中农药残留的新型检测装置,其酶的固定化对OPH传感器的灵敏度和稳定性有重要的影响。研究了几种酶固定化载体、孔径大小、固定方式、固定方法（试剂组成）对传感器pH值的影响。结果显示：采用孔径为0.45μm的硝酸纤维素膜制备固定化酶片的pH值要大于其余几种;采用浸泡方式制备固定化酶片的pH值明显大于传统的滴定法;采用牛血清白蛋白（BSA）、戊二醛交联固定的效果优于酶直接吸附法和BSA固定法,且当戊二醛体积分数为2.5％,BSA为10％时,酶固定化效果最好。     

石油降解菌的固定化材料研究进展

随着微生物固定化技术在石油污染治理领域内发挥的作用越来越大,关于固定化微生物技术的研究越来越受到关注,而载体材料在微生物固定化技术中发挥着关键的作用。本文阐述了对固定化石油降解菌载体材料性能的要求,对无机物、天然有机物、合成高分子、复合材料等不同类型载体在石油降解菌固定化中的研究与应用以及对各类材料固定化石油降解菌的降解效果进行了综述。对比概述了各种不同载体材料对应的固定化方法,指出了各载体材料、相应固定方法的优劣势及适用场景,描述了石油降解菌固定化技术及相关载体材料今后的发展趋势。     

All‐Organic Dual Spin Valves with Well‐Resolved Four Resistive‐States

The formation of all‐organic dual spin valves (DSVs) with three organic spin‐selective layers, that is, spin‐injection, spin‐detection, and an additional spin‐filtering layer at the intermediate, is reported. As spin‐selective layers, manganese‐ and cobalt phthalocyanines, which are well‐known single‐molecule magnets, are used in their immobilized forms, so that all‐organic DSVs can be prefabricated for characterization. The three spin‐selective layers have provided four configurations with at most two spin‐flip interfaces enforcing spin‐flipping at the two nonmagnetic organic spacer layers, for which copper phthalocyanine is used. Since a couple of the four configurations have exhibited similar resistivities, the degeneracy in the resistive‐states is broken through asymmetric spin‐injection and spin‐detection layers and also through asymmetric thickness of the nonmagnetic spacer layers. When both the spin‐flip interfaces are made operative independently, a 2‐bit logic with four distinct resistive states can be achieved.     

酶的固载技术及纳米电化学酶生物传感器的研究进展

该文较详细地阐述了酶的固定化方法和各自的优缺点,以及综述了近年来各种类型的纳米材料在电化学酶生物传感器中的应用,并对今后的工作进行了展望.