草酸青霉BZH-2002产果胶酶特性研究

对草酸青霉菌（Penixillium oxalicum）BZH-2002菌株固体发酵果胶酶的特性及浸提条件进行了研究,确定其最佳产酶时期为72—92h,利用干物质量最快的时期为24—72h发酵产酶期间培养基介质中pH值呈“V”字形变化。该菌株以甜菜渣、葵花盘为碳源,以（NH）2SO4为氮源时产酶率最高,分别高达4．33万和4．56万U／g干物质,（NH4）2SO4最佳用量0．9g/10g甜菜渣。此外,浸提方法对果胶酶产率也有一定影响,1％NaCl作为浸提液的效果最好,最佳浸提时间1h,浸提温度25—40℃。     

一株霉菌产木聚糖酶固态发酵培养基的优化及酶学性质研究

对一株霉菌B45固态发酵产木聚糖酶的培养基组分进行优化,通过单因素实验观察了不同碳源、氮源、无机盐、水料比4种因素对产木聚糖酶的影响,确定了4种最佳的单因素成分。在单因素的基础上,再通过正交实验确定了所试因素的最佳组合,并对其粗酶的酶学性质进行了研究。结果表明,在培养基组分为玉米芯与麸皮的比例=7∶3,硫酸铵为1.5%,KH2PO4为0.8%,水料比为2.1∶1时,得到的酶活力最高,产酶量可达1 079.93 U/g。其粗酶液的最适反应温度为60℃,最适反应pH为5,在pH5～pH6的范围内酶活性较稳定。但粗酶液的热稳定较差,在40℃条件下酶活力开始下降,当温度升至70℃时酶活力损失85%以上。     

番石榴叶中总黄酮最佳提取条件的探讨及其抑菌作用的研究

设计正交实验,采用超声波法从番石榴叶中提取总黄酮,综合各因素确定最佳提取条件为乙醇浓度40％,固料比（番石榴干叶：浸提剂）=1g：60mL,浸泡25h超声波处理时间50min,获得提取液总黄酮含量为9．9167％。采用牛津杯法做抑菌实验,结果表明番石榴叶和果实的水提、醇提粗提液对大肠杆菌、金黄色葡萄球菌、枯草芽孢杆菌、阴沟肠杆菌、溶血葡萄球菌等均有很好的抑菌效果。叶和果实的总黄酮提取液的抑菌作用也很明显。番石榴有望作为药食同源产品和天然食品防腐剂进行开发利用。     

木霉T6木聚糖酶制剂研究

本文研究了木霉Ｔ６（Ｔｒｉｃｈｏｄｅｒｍａ ｓｐ．）产木聚糖酶固态发酵过程和木聚糖酶制剂制备,结果显示,固体曲培养４ｄ时酶活力最高,固体曲最适液固浸提比为７：１。木聚糖酶在６０～６５％硫酸铵饱和度下盐析效果最好。冷冻干燥和４０℃烘干酶粉得率分别为６８．３％和４５．７％。酶最适反应ＰＨ为４．５,最适反应温度５０℃,在不同温度下１小时后的半失活温度为４７．７℃。     

响应曲面法优化方格星虫多糖提取工艺

为了优化提取方格星虫多糖工艺实验条件,本研究以海南三亚海域方格星虫为主要原料,用胰蛋白酶作为酶解酶,在单因素实验基础上,采取响应面法研究超声波辅助酶法提取方格星虫多糖最佳工艺条件;探讨了p H值、液料比、超声波时间、酶底比、超声波温度、超声波功率、反应时间等7个因素的交互作用及其最佳水平。结果表明在超声波辅助酶法提取方格星虫多糖的实验过程中,单因素的最佳条件酶底比为2.5%、温度为50℃、浸提时间为2 h、料液比为1:17 g/m L、超声时间为1 h、pH值为8、超声功率为960 W,多糖的最大提取率为3.24%。该方法实验条件要求不苛刻,浸提时间短,提取率高,是一项新的实验尝试,实验结果为优化方格星虫的多糖提取理论参考。     

培养条件对一株木霉产纤维素酶过程影响的研究

采用固态发酵和连续监测正交实验结果的方法,研究了培养温度、初始pH值、液料比和接种量对一株木霉(Trichodermasp.)发酵过程中微晶纤维素酶活、CMC酶活和滤纸酶活的影响及影响程度。指出液料比在整个发酵过程中是对产酶影响最大的因素,温度在发酵初期影响较大,初始pH和接种量的影响均不显著。总体看来,培养温度、初始pH值、液料比和接种量分别为30℃、4、7和5%是比较合适的。     

黑曲霉固态发酵制备β-葡萄糖苷酶发酵条件优化

对一株黑曲霉菌固态发酵产β-葡萄糖苷酶的产酶条件进行了优化.通过单因素实验考察了不同碳源、氮源、固液比、诱导剂及产酶时间等6 种因素对产β-葡萄糖苷酶的影响.在单因素的基础上,进行了五因素四水平正交实验.结果表明,在培养基组分中秸秆与麦麸的比例为3:3,固液比为1:3,氮源为3% 硝酸铵,发酵时间为5d,采用CMCNa 作为诱导剂时得到的β-葡萄糖苷酶活力最高,可达40.06 U/g.     

黑曲霉产木聚糖酶固态发酵条件及部分酶学性质的研究

实验以棉粕和玉米秆为主要原料,采用单因素和正交实验方法对黑曲霉固态发酵产木聚糖酶的培养条件进行了优化,为了获得高酶活产品的发酵条件。结果表明,最适培养基组分为棉粕和玉米秆的比例为3∶2,固水比为1∶1.2,尿素的最适添加量为2%(以干重计),KH2PO4的最适添加量为0.2%。在此条件下,菌株产酶活性可达6 529U/g干曲。该酶的最适反应温度为55℃,最适pH为5.0,pH稳定范围较宽,在30℃、pH 3.5~6.0范围内处理100min,酶活保持在85%以上,但耐热性不是很理想,在60℃保温30min残余酶活只有17%。     

肺形侧耳发酵培养基优化及多糖提取工艺

通过碳源、氮源单因素实验和正交实验,对野生肺形侧耳进行发酵培养基优化。选取浸提时间、浸提温度及液料比3个因素,以胞内粗多糖提取率为指标,采用正交实验设计确定菌丝体胞内多糖提取的最佳工艺。结果表明,适宜肺形侧耳深层发酵的培养基为蔗糖1.5%,麸皮5%,蛋白胨0.6%,KH₂PO₄ 0.15%,MgSO₄ 0.75%,VB₁ 0.01%。胞内多糖提取的最佳工艺为浸提时间2h,液料比50:1,浸提温度90℃,此条件下多糖提取率为34.35%。     

里氏木霉306产t-PA固态发酵条件的研究

对基因工程菌株里氏木霉(Trichodermareesei)306生物合成组织型纤溶酶原激活剂(t-PA)的固态发酵培养基成分和发酵条件进行了研究;分析了发酵过程中t-PA的生成、总糖的消耗和菌体生长的规律。在优化的固体发酵条件下,t-PA的最大酶活是924.63IU/g干重培养基,较初始条件下提高了5倍。通过浅盘进行了放大实验,最大酶活为983.64IU/g干重培养基,t-PA合成速率为:13.66IU/g干重培养基.h,较三角瓶固态发酵最高产酶提高了6.38%,产酶速率提高了24.07%。     

Immobilization of inulinase obtained by solid-state fermentation using spray-drying technology

Abstract

This work focuses on the immobilization of a crude inulinase extract obtained by solid-state fermentation using spray-drying technology. Maltodextrin and arabic gum were used as immobilizing agents. The effects of inlet air temperature, maltodextrin/arabic gum ratio and mass fraction of crude enzyme extract on the activity of immobilized inulinase were assessed using a central composite rotatable design (CCRD) (2³). The optimum operational conditions for the immobilization of inulinase by spray-drying was obtained at an inlet air temperature of 200°C, mass fraction of crude enzyme extract of 0.5 wt% and using only arabic gum as immobilizing agent. The immobilized enzyme had good thermostability, comparable with other inulinases obtained from different microorganisms. The method used gave good enzyme activity after immobilization and could be applied to other enzymes which have good thermal stability.     

Production,partial characterization,and immobilization in alginate beads of an alkaline protease from a new thermophilic fungus <Emphasis Type="Italic">Myceliophthora</Emphasis> sp.

Thermophilic fungi produce thermostable enzymes which have a number of applications, mainly in biotechnological processes. In this work, we describe the characterization of a protease produced in solidstate (SSF) and submerged (SmF) fermentations by a newly isolated thermophilic fungus identified as a putative new species in the genus Myceliophthora. Enzyme-production rate was evaluated for both fermentation processes, and in SSF, using a medium composed of a mixture of wheat bran and casein, the proteolytic output was 4.5-fold larger than that obtained in SmF. Additionally, the peak of proteolytic activity was obtained after 3 days for SSF whereas for SmF it was after 4 days. The crude enzyme obtained by both SSF and SmF displayed similar optimum temperature at 50°C, but the optimum pH shifted from 7 (SmF) to 9(SSF). The alkaline protease produced through solid-state fermentation (SSF), was immobilized on beads of calcium alginate, allowing comparative analyses of free and immobilized proteases to be carried out. It was observed that both optimum temperature and thermal stability of the immobilized enzyme were higher than for the free enzyme. Moreover, the immobilized enzyme showed considerable stability for up to 7 reuses.     

微小毛霉凝乳酶的分离纯化研究

研究微小毛霉(HL-1)凝乳酶的分离纯化条件及方法。研究酶的最适浸提温度、酶的浸提pH值和最适浸提时间,探讨离子浓度、加水量对浸提效率的影响,利用高速冷冻离心法、有机溶剂沉淀法,膜分离法和层析法等对粗酶液进行了分离。利用光谱法对纯化样品进行检测。酶的最适浸提温度为30℃;最适pH为6.0;浸提10 h活力最高;1%的氯化钠有利于酶的分离,加水比例为15时有利于提取,在10 000 r/min下离心10min澄清效果最好,95%的酒精沉淀效果最好,利用0.2μm的微滤膜可除去发酵液中的菌体,8 000的超滤膜可拦截凝乳酶蛋白,S300的填料可有效分离凝乳酶,纯度达95%以上。     

烟梗为原料固态发酵生产果胶酶

以烟梗为主要原料,采用单因素和正交实验对筛选到的丝状菌JXY-17固态发酵产果胶酶的培养基进行了优化,正交实验结果表明,影响该菌株产果胶酶的因素依次为含水量(料水比)(A)＞(NH4)2SO4(B)＞KH2PO4(D)＞吐温-80(C),产酶培养基组成为A3B2C2D1,即固液比1∶1.5,(NH4)2SO4 5.0％,吐温-80 0.10％,KH2 PO40.20％.采用该固态发酵培养基,自然pH,接种量25 mL,装料量为50 g(干基)/1000 mL三角瓶,30℃恒温培养6d,产酶最高达8171.35U/g干曲,为初始酶活的3.8倍.提取酶液后的残余烟梗还可用于提取烟梗纤维类物质.残余烟梗的化学成分检测结果表明,与原始烟梗(或对照)相比,其果胶质降低了45％左右,残余烟梗固形物回收率约50％.     

Microbial biomass production from rice straw by fermentation with Penicillium janthinellum

Production of microbial biomass through fermentation of pretreated rice straw using Penicillium janthinellum (St-F-3B) is reported, with emphasis on the use of non-effluent generating pretreatment procedures. The fungus readily metabolized a rice straw substrate that had been subjected to alkali pretreatment by steaming at atmospheric pressure followed by the neutralization of the alkali. The crude protein content of the microbial biomass averaged 15–20%. The fermentation could be carried out in aerated-agitated fermenters using fertilizer grade nutrient salts to produce a biomass with 17.5% crude protein. When operated on a semicontinuous basis using 20% of the previous batch as inoculum, successive batches produced a biomass product with 12–19% crude protein content in 48 h. The problems of developing a technology for protein from agricultural residues with particular reference to developing countries are discussed.     

SMA基微孔膜固定化β-半乳糖苷酶的研究

以超临界二氧化碳（SCCO2）为分散介质在聚偏氟乙烯（PVDF）微孔膜表面和孔内进行马来酸酐和苯乙烯的接枝共聚,合成出超高分子量的苯乙烯/马来酸酐交替共聚物（SMA）基微孔PVDF膜。以SMA基PVDF膜为载体通过酸酐基和酶分子上的氨基偶联,制备出具有酶催活性的功能性分离膜。考察了影响酶固定化的因素,确定其最佳固定化条件为: 温度,4oC;pH,8.2; 酶/膜,1:10;反应时间,6h。固定化酶膜的最适温度为55oC,最适pH为7.8,均比自由酶稍高;Km（0.3mM/L）与自由酶接近。固定化酶膜活力达13.5 U/cm2 膜, 比活为280.0 U/mg 蛋白,蛋白载量为68.2 g/cm2 膜,相对活力为89.0%。固定化酶膜表现出良好的操作稳定性和储存稳定性,SMA基PVDF微孔酶膜超滤制备低乳糖牛奶实验表明该技术应用前景广阔。     

Optimization of fermentation conditions for gluconic acid production using Aspergillus niger immobilized on cellulose microfibrils

The optimisation of gluconic acid fermentation using immobilized Aspergillus niger on a highly porous cellulose support is described. Experimental results showing the effects of variations in oxygen partial pressure, glucose concentration and biomass concentration have been obtained with a continuous recirculation reactor. Levels of dissolved oxygen and glucose concentrations during fermentation significantly affect the production and fermentation time. The optimum biomass requirement on a porous cellulose support has been estimated to be 0.234 mg cm⁻² for efficient bioconversion. Increasing the quantum of biomass beyond this value resulted in an overgrown biofilm, which affected productivity adversely. Morphological characteristics of immobilized A. niger have also been investigated.     

Streptomyces thermocerradoensis I3 secretes a novel bifunctional xylanase/endoglucanase under solid-state fermentation

Lignocellulosic wastes can be potentially converted into several bioproducts such as glucose, xylo-oligosaccharides, and bioethanol. Certain processes, such as enzymatic hydrolysis, are generally needed to convert biomass into bioproducts. The present study investigated the production of xylanases and cellulases by Streptomyces thermocerradoensis I3 under solid-state fermentation (SSF), using wheat bran as a low-cost medium. The activities of xylanase and carboxymethyl cellulase (CMCase) were evaluated until 96 hr of incubation. The highest enzyme activity was observed after 72 hr of incubation. The crude enzyme extract was sequentially filtered, first using a 50 kDa filter, followed by a 30 kDa filter. Fraction 3 (F3) exhibited activities of both xylanase and CMCase. Xylanase and CMCase showed optimum activity at 70°C and pH 6.0 and 55°C and pH 6.0, respectively. The zymogram analysis showed a single activity band with a molecular mass of approximately 17 kDa. These findings provide strong evidence that the enzyme is a bifunctional xylanase/endoglucanase. This enzyme improved the saccharification of sugarcane bagasse by 1.76 times that of commercial cellulase. This enzyme has potential applications in various biotechnological procedures.