The Feasibility of Immobilization of Bioflocculant-producing Bacteria Using Mycelial Pellets as Biomass Carriers

Bioflocculant-producing bacteria Agrobacterium tumefaciens F2 and Bacillus sphaeicus F6 were immobilized onto mycelial pellets to investigate the bioflocculant-producing potential of this combined organism and the corresponding flocculating efficiency. The atomic force microscope ( AFM) images of mycelial surface indicate that the mycelia pellet can immobilize bioflocculant-producing bacteria F2 and F6 as a biomass carrier. The flocculating efficiency of bioflocculant produced by this combined organism was studied under the optimum flocculating conditions obtained by Response Surface Methodology ( RSM ) . The fermentation yield of the combined mycelial pellet is about 2. 6 g / L,which is higher than that of the free bacteria ( only 2. 2 g / L) . Flocculating efficiency of the combined mycelial pellet was comparable with that of bioflocculant generated by the free bacteria. The bioflocculant yield is enhanced and the flocculating efficiency of the co-culture is uninfluenced after immobilized with mycelial pellet as a carrier. In conclusion,the mycelial pellet is feasible as a biomass carrier for the immobilization of bioflocculant-producing bacteria.

STUDY ON THE IMMOBILIZATION OF PAPAIN WITH A MACROPOROUS BEAD CARRIER OF COPOLYMER CONTAINING MONOMER UNITS OF NAMINOETHYL ACRYLAMIDE AND VINYL ALCOHOI

A kind of macroporous bead carrier of copolymer containing monomer units of N-aminoethyl acrylamide and vinylalcohol was synthesized, i.e. the MR-AA carrier. Papain was immobilized on the carrier using glutaraldehyde as the couplingagent. The enzymatic activity of the immobilized papain was compared with free papain using casein as a substrate, and theeffects of glutaraldehyde concentration, pH, temperature, time and papain amount added on the activity recovery were alsoinvestigated. The results show that the MR-AA carrier contains reactive primary amine groups, hydrophilic amido links andhydroxyl groups, as well as macroporous structures based on its matrix (MR-AV matrix), furthermore, the activity recoveryof papain in the immobilization could reach 48%/～58%. In comparison with free papain, the resulting immobilized papainexhibits a remarkable thermostability and better reusability.

Nickel-Carnosine complex:A new carrier for enzymes immobilization by affinity adsorption

Immobilization is an effective method to promote the application of enzyme industry for improving the stability and realizing recovery of enzyme.To some extent,the performance of immobilized enzyme depends on the choice of carrier material.Therefore,the development of new carrier materials has been one of the key issues concerned by enzyme immobilization researchers.In this work,a novel organic–inorganic hybrid material,nickel-carnosine complex(NiCar),was synthesized for the first time by solvothermal method.The obtained NiCar exhibits spherical morphology,hierarchical porosity and abundant unsaturated coordination nickel ions,which provide excellent anchoring sites for the immobilization of proteins.His-tagged organophosphate-degrading enzyme(Opd A)and x-transaminase(ω-TA)were used as model enzymes to evaluate the performance of NiCar as a carrier.By a simple adsorption process,the enzyme molecules can be fixed on the particles of NiCar,and the stability and reusability are significantly improved.The analysis of protein adsorption on NiCar verified that the affinity adsorption between the imidazole functional group on the protein and the unsaturated coordination nickel ions on NiCar was the main force in the immobilization process,which provided an idea way for the development of new enzyme immobilization carriers.

Immobilization of carbonic anhydrase for facilitated CO2 capture and separation

Carbonic anhydrase(CA)as a typical metalloenzyme in biological system can accelerate the hydration/dehydration of carbon dioxide(CO2,the major components of greenhouse gases),which performer with high selectivity,environmental friendliness and superior efficiency.However,the free form of CA is quite expensive(~RMB 3000/100 mg),unstable,and non-reusable as the free form of CA is not easy for recovery from the reaction environment,which severely limits its large-scale industrial applications.The immobilization may solve these problems at the same time.In this context,many efforts have been devoted to improving the chemical and thermal stabilities of CA through immobilization strategy.Very recently,a wide range of available inorganic,organic and hybrid compounds have been explored as carrier materials for CA immobilization,which could not only improve the tolerance of CA in hazardous environments,but also improve the efficiency and recovery to reduce the cost of large-scale application of CA.Several excellent reviews about immobilization methods and application potential of CA have been published.By contrast,in our review,we stressed on the way to better retain the biocatalytic activity of immobilized CA system based on different carrier materials and to solve the problems facing in practical operations well.The concluding remarks are presented with a perspective on constructing efficient CO2 conversion systems through rational combining CA and advanced carrier materials.

Immobilization of Thermomyces lanuginosus lipase on metal-organic frameworks and investigation of their catalytic properties and stability

Surface adsorption is a convenient and readily available method for immobilizing enzymes on metal-organic frameworks(MOFs).Metal-organic framework-5(MOF-5),isoreticular metal-organic frameworks-3(IRMOF-3),and multivariate analysis of MOF-5/IRMOF-3(MMI)with a half-amino group(-NH2)were prepared in this study.Thermomyces lanuginosus lipase(TLL)was chosen as a commercially available enzyme for immobilization on the surfaces of these MOFs.Briefly,1.5 mg of TLL was added to 10 mg of the MOFs,and after 24 h,67,74,and 88%of the TLL was immobilized on MOF-5,IRMOF-3,and MMI,respectively.Fourier transform infrared spec-troscopy,X-ray diffraction,thermogravimetric analysis,scanning electron microscopy,energy-dispersive X-ray analysis,and Brunauer-Emmett-Teller analysis were used to characterize the resulting biocomposites.TLL@MOF-5,TLL@IRMOF-3,and TLL@MMI exhibited activities of 55,75,and 110 U/mg,respectively.Investigation of the activity and stability of the prepared biocatalysts showed that TLL immobilized on MMI was 2.34-fold more active than free TLL.TLL@MMI exhibited high stability and activity even under harsh conditions.After 24 h of incu-bation in a mixture of 50%(v/v)MeOH,TLL@MMI retained 80%of its activity,whereas TLL@MOF-5 and free TLL lost 50 and 60%of their activities,respectively.TLL@MMI was used to synthesize 2-arylidenehydrazinyl-4-arylthiozole derivatives(91-98%)in a one-pot vessel by adding benzaldehydes,phenacyl bromides,and thiosemi-carbazide to water.The efficiency of the 4a derivative with free TLL was 43%,whereas that with TLL@MMI was 98%.

A novel knotted cotton-thread carrier:Its potential use in achieving the biomass renewal of Phanerochaete chrysosporium in an immobilized growth system

In order to achieve an innovative strategy to renew the biomass of Phanerochaete chrysosporium in an immobilized growth system which can maintain white-rot fungi biomass, a novel knotted cotton-thread carrier was designed and made. By using a high-speed stirring apparatus under the conditions of 1400 r/min stirring speed for 6 min, mycelia immobilized on the knotted cotton-thread carriers were exfoliated completely and homogenized to a proper size. Furthermore, the homogenized mycelia from the immobilized mycelia can resume their growth on the knotted cotton-thread carriers in agitated flask cultures. The average regrowth biomass on the new carriers and the reused carriers was 0.0171 g/carrier and 0.0314 g/carrier, respectively. It proves that the knotted cotton-thread carrier performs perfectly in homogening the immobilized mycelia to achieve the biomass renewal of P. chrysosporium in an immobilized growth system.

酶催化在废水处理中的进展

随着人类社会的发展,高度集中化的城市或工业园区容易发生突发性环境污染事故,对城市环境及人民生命安全造成威胁。但常规的处理工艺无法应对突发性环境污染造成的超标污染物,如何采用有效的应急处置技术,在最短时间有效去除污染物,并且技术具备快速进场属性,已成为当前环保领域所面临的新课题。生物酶催化作为一种低成本、低能耗的技术在废水处理领域已受到了广泛的研究。本文综述了酶催化在废水处理和污泥处置方面的优势,总结了当前酶催化应用研究的固定技术与研究进展。

自固定化酶法制备石莼寡糖工艺研究

为提高石莼寡糖产量,该研究通过基因工程技术构建带有铁蛋白标签的石莼多糖裂解酶(Ulvan-F)质粒载体,通过其独特的自组装特性,制备自固定化酶并应用于酶解石莼多糖。采用单因素试验和响应面试验优化其发酵工艺条件,并对其制备石莼寡糖的重复使用率、得率及分子质量进行测定。结果表明,最佳酶解工艺条件为:酶解温度25℃,酶解pH 9.0,底物浓度2.5%。在此优化条件下,石莼寡糖得率为27.76 mg/g,Ulvan-F重复10次循环后依旧保持43.77%的活性,其制备石莼寡糖总得率为165.43 mg/g,比传统游离酶制备石莼寡糖得率(117.82 mg/g)提高了40.41%,Ulvan-F酶解产物平均分子质量为492.36 Da。Ulvan-F具有在低速离心条件下即可纯化、易与产物分离及可重复使用的优点,能应用于宏量制备石莼寡糖的工业生产中。

微生物固定化技术及在废水处理中的应用

在探究了微生物固定化技术在不同废水环境中的应用情况后,总结了不同微生物固定方法且比较了各种方法的优缺点,并对微生物固定化载体的选择因素及材料分类进行说明。最后,简要讨论了微生物固定化技术在水污染治理实际应用中所存在的问题,并对未来的研究提供了参考方向。

酶固定化技术的最新研究进展

酶作为一种催化性能好且安全可靠的生物催化剂,在食品、医药及环境治理等诸多领域得到了广泛应用,但因受限于游离酶较差的环境稳定性而难以实现进一步的工业化应用。酶固定化技术有助于提高游离酶对敏感环境的耐受性和操作过程中的稳定性,大大缩减了应用成本。回顾了近五年内固定化技术的发展及现状,总结了吸附法、结合法等传统固定化方法,共固定化酶法等新型固定化方法,以及天然材料载体、复合材料载体和纳米载体等不同固定化载体在各个领域的研究进展。相比于游离酶,固定化酶体系在稳定性和重复使用性等方面得到了显著提升,但同时也存在一些不足,如固定后的活性回收率降低、载体合成途径繁琐且成本较高以及固定化酶作用机理尚不完善等。结合这些不足之处提出了酶固定化技术在未来的发展方向。

酶固定化技术及固定化酶应用的研究进展

酶是一种对环境友好的生物催化剂,在环境修复、医药、化工和食品等领域广泛应用,但游离酶的催化性能易受环境因素的影响。酶的固定化技术是提高游离酶的催化稳定性的主要技术之一。首先综述了几种不同的酶固定化技术,介绍了不同固定化技术的优点及特点;其次介绍了不同固定化载体对不同酶的固定效果,并分析了其优势;最后讨论了固定化酶面临的挑战和未来发展前景。

微生物固定化技术在铬污染修复中的应用及研究进展

由于铬及其化合物广泛的工业应用,在许多地方造成了不同程度的铬污染,严重危害生态环境和人类健康。生物修复技术因其技术投资和运行成本低而被认为是Cr(VI)污染修复的一种可行的选择。然而,在高浓度Cr(VI)存在下,微生物的损失、对微生物的毒性等因素阻碍了其商业应用。微生物固定化技术(Microbial immobilization technology,MIT)能够克服传统生物修复技术的缺点,具有铬耐受性好、稳定性高、反应速度快、活性高等优点,近年来得到迅速发展,并多次应用于铬污染修复过程。但目前对该技术在铬污染修复中的研究和应用还处于起步阶段。基于此,本文从微生物固定化载体的选择、微生物固定的方法、微生物的筛选、微生物固定化装置等方面对微生物固定化技术在铬污染修复中的应用及研究进展进行综述,并对未来的研究和实际应用提出建议和展望,以期为Cr(VI)污染的修复研究提供有价值的参考。

真菌菌丝球及其作为载体在污水处理中的研究进展

真菌在液体培养条件下可形成内部中空,表面致密的菌丝球,具有絮凝性能好、不易堆积、生长条件宽泛、易培养等优点。研究者已对其形成机制和培养条件开展了大量研究。近年来关注点逐渐转向其应用方面,目前真菌菌丝球已在污水处理、资源与能源回收等领域被广泛研究。主要介绍了液体培养条件下真菌菌丝球自组装机制,营养元素和培养条件对菌丝球形成的影响;概述了真菌菌丝球搭载纳米颗粒、微生物、生物炭对多种污水进行处理的研究及其在污水处理中的潜力与面临的挑战;另外,介绍了真菌菌丝球处理各类污水的案例以及与之配套使用的反应器的运行特点和应用情况。真菌菌丝球的利用应注重其多元化及协同化发展,依托其自身优势搭配其它物质发挥协同作用,推动其在污水处理和环境修复方面更有效的应用。研究结果可为真菌在污水处理中的应用提供指导和借鉴。

陶粒-火山岩固定化载体制备及油污土壤修复

为提高石油污染土壤修复效果,该研究通过改进搅拌-交联方法制备陶粒-火山岩复合载体,同步进行微生物/漆酶的固定化,并结合SEM、BET、FTIR及土壤生物学特性等分析固定化载体性质及其在修复石油污染土壤中的差异。研究表明:陶粒-火山岩复合载体在石油烃吸附性能上较单一载体提升约50%,所制备的固定化载体比表面积提升3.1%~51.1%,孔容提升8.6%~50.9%;固定化微生物负载量达109cells/g,储存15 d活细胞比例最高达60.89%,固定化漆酶相对活性在循环利用5次后保持在19%以上,储存30 d为56%左右;土壤石油烃修复效果最高达58.98%(固定化菌-酶复合制剂),土壤脱氢酶、脲酶、过氧化氢酶及多酚氧化酶活性提升效果显著,且存在显著正相关关系;微生物结构分析表明添加固定化载体会使土壤微生物群落结构变化并出现优势物种,如铜绿假单胞菌属(Pseudomonas)、枝芽胞杆菌属(Virgibacillus)、大洋芽胞杆菌属(Oceanobacillus)。

脂肪酶固定化技术的研究进展

该文介绍了脂肪酶的传统及新型固定化技术,特别针对纳米载体、磁性载体、微波辅助固定化技术、膜固定化技术等近年来发展的新载体和新技术进行概述,描述了通过固定化来改善脂肪酶的催化性能,包括酶的活力、稳定性、最适条件以及特异性等。提出目前脂肪酶固定化所面临的稳定性差、难以工业化应用等问题,并指出未来脂肪酶固定化技术应向着性质稳定、操作简单以及规模化生产的方向发展。

Noria-PEI改性PVA载体固定化溶菌酶用于污泥发酵产VFAs研究

生物酶促进污泥厌氧消化具有反应温和、高效环保等优点,然而回收困难和催化稳定性差严重制约其应用,固定化酶是解决上述问题的关键。采用水轮酚(Noria)和聚乙烯亚胺(PEI)共沉积法改性聚乙烯醇(PVA)载体,并研究了Noria-PEI改性PVA载体固定溶菌酶对污泥厌氧发酵产挥发性脂肪酸(VFAs)效能的影响。结果表明,固定化溶菌酶可强化污泥发酵提高SCOD,在36 h内SCOD最高浓度达到2 892.4 mg/L,相比空白组提升3.4倍(第6天),VFAs质量浓度在第4天达到峰值2 130.8 mg/L,乙酸和丙酸占比达到61.8%~80.7%。固定酶系统中污泥的平均粒径为42.957μm,比表面积为0.413 m^(2)/g,固定化溶菌酶强化了颗粒态污泥水解。微生物群落结构分析显示,在固定酶系统中Firmicutes、Proteobacteria和Bacteroides等水解产酸菌门占比较高;在属水平上,以Macellibacteroides、Petrimonas、Lactobacillus和Clostridium_sensu_stricto_1菌属为主,从微观层面上解释了固定酶强化污泥发酵产酸机理。

酶固定化技术及其在食品工业的应用进展

酶是高效的生物大分子催化剂,广泛应用于食品工业。然而,游离酶活性和稳定性差,重复使用性差。因此,酶常被固定在惰性(不溶性)载体上,以提高其稳定性和重复使用性,即酶的固定化。为了提高固定化酶的生物催化效率,人们研究并开发了多种载体。合适的载体材料和固定化方法对于优化固定化酶的性能至关重要。载体材料的选择通常需要考虑其生物相容性、化学和热稳定性、反应条件下的不溶性、易于再生和重复使用性以及成本效益等。酶固定化技术应用于食品工业中不仅能够提高酶的稳定性和重复利用率,还可改善食品质量、降低加工成本。总结了酶固定化的常见载体,并重点介绍了其在食品工业中的应用,以期为食品工业中酶固定化技术的应用研究提供参考。

Fe_(3)O_(4)磁性载体的制备及其固定脂肪酶的研究

利用化学共沉淀法制备Fe_(3)O_(4)磁性内核,并以其为载体采用吸附法结合溶胶-凝胶法固定脂肪酶。分别以内核包硅之前和包硅过程中加入脂肪酶两种方法固定脂肪酶,对两种方法得到的固定化脂肪酶测定酶活回收率。实验表明:先吸附脂肪酶后包硅所得酶活回收率较高。同时对固定条件进行优化,在给酶浓度1.5 g/L、pH 8.5、温度30℃、固定时长6 h条件下进行包硅,所得固定酶酶活回收率最高为40.57%。且脂肪酶经过固定后具有了较好的重复使用性和储存稳定性。磁性载体的引入有利于脂肪酶从反应体系中分离,降低了使用成本。而吸附法与溶胶-凝胶法相结合,增加了脂肪酶的固定稳定性。

Enantioselective Conversion of Racemic Felodipine to S(-)-Felodipine by Aspergillus niger and Lipase AP6 Enzyme

The present study involves the enantioselective resolution of racemic Felodipine by using free and immobilized forms of microbial cultures as well as an enzyme (Lipase AP6). Among the microbial cultures employed in the present study, Aspergillus niger, Sphingomonas paucimobilis, Cunninghamella elegans, Escherichia coli, Pseudomonas putida and Cunninghamella blakesleeana were found to possess capability of enantioselective resolution of racemic Felodipine. The enantiomeric excess (ee%) of Felodipine after reaction catalyzed by whole-cell A. niger and S. paucimobilis was found as 81.59 and 71.67%, respectively. Immobilization enhanced the enantioselectivity (enantiomeric ratio (E)) of the biocatalysts and hence this led to enhanced enantiomeric purity of the drug. The ee% values were found to be enhanced in reactions catalyzed by A. niger and S. paucimobilis cultures after immobilization as 98.27 and 93.56%, respectively. Enantiomeric ratio (E) of the reactions catalyzed by all the biocatalysts has been improved after immobilization. E value of the reaction catalyzed by immobilized A. niger was found to be excellent (E > 100) and hence the drug showed high enantiomeric purity. In lipase AP6 catalyzed study, the enantioselectivity was enhanced after immobilization with excellent E value, which led to enhanced enantiomeric purity of the drug (99.21% ee%).

适用于酶包埋的高分子载体材料研究进展

固定化酶作为一种生物催化剂 ,它能在较为温和的反应条件下 ,高选择性、高效率地催化某些化学反应 ,并且不会对环境造成污染。本文对适用于酶包埋的高分子载体材料的制备 ,优缺点以及制备载体材料的优化方法做了较为详细的叙述 。