纳豆激酶生产菌的筛选及发酵纳豆特性研究

为开发具有特定生理活性的新型纳豆保健品,从发酵豆制品中分离筛选得到一株纳豆激酶高产菌株。利用该菌株以及市售的3种纳豆中的纳豆菌进行纳豆发酵,比较了4株纳豆菌发酵纳豆的特性,并对纳豆激酶活性进行分析。结果表明5号菌株发酵生产纳豆周期短,颜色金黄,具有酱香味,拉丝长度最佳。同时,对产纳豆激酶的最佳发酵时间进行研究,结果表明发酵至17 h纳豆激酶活性达到最大值。     

纳豆菌产生抗菌物质的培养条件的优化

对纳豆菌产生抗菌物质的培养基的组成进行了优化,并探讨了温度、pH、培养方式和接种量对纳豆菌生长及抗菌作用的影响,发酵的适宜温度为25℃－30℃,培养基的最适初始pH为6．5－7．5,最适接种量6％,振荡培养优于静置培养。     

纳豆菌液体发酵条件的优化

纳豆是日本传统的大豆发酵食品,用以发酵纳豆的菌株即纳豆菌不仅具有分解蛋白质、碳水化合物、脂肪等大分子物质的性能,使发酵产品中富含氨基酸、有机酸、寡聚糖等多种易被人体吸收的成分,而且纳豆具有多种保健功能,如溶血栓、抗肿瘤、降血压、抗菌、预防骨质疏松、抗氧化等。纳豆菌还能分泌各种酶和维生素,从而可促进小肠黏膜细胞的增殖,保证肠功能的正常。本研究是纳豆菌微生态制剂的研制的一部分。1　材料与方法　①菌种:纳豆菌(Bacillussub tilisvar.natto)BN .0 30 1 ,本实验室保藏。②生物量测定:发酵完成后取1mL发酵液稀释2 0倍(活…     

纳豆多糖发酵工艺的优化及清除自由基研究

考察了纳豆菌接种量、料液比、发酵温度及发酵时间对纳豆菌发酵豆粕产生的纳豆多糖得率的影响,进行了响应面设计实验,得出最佳发酵工艺参数;探究了纳豆多糖的抗氧化活性,并与维生素C进行比较。实验结果表明:接种量为0. 6%,料液比为1∶3,发酵温度40℃,发酵时间48 h,在此工艺条件下水溶性纳豆多糖得率最高为4. 371%。纳豆多糖浓度为1. 5 mg/mL时,对羟基自由基的清除率是50. 07%,对超氧阴离子自由基的清除率达95. 79%,对DPPH自由基的清除率为16. 35%。     

纳豆激酶的纯化及活力测定

利用SephadexG—100s柱凝胶层析法从纳豆菌（BacillusNatto）提取液中分离纯化出具有体外活性的纳豆激酶,并通过纤维蛋白平板法测定其纤溶活力,发现其具有较强的促进纤维凝块溶解的作用。     

纳豆菌体外抑制大肠杆菌的培养基优化

目的:考察纳豆菌培养基组成对其增长倍数及抑菌效果的影响.方法:将纳豆菌N7对大肠杆菌的体外抑制作用进行动力学分析,通过单因素试验及正交试验确定纳豆菌抑制大肠杆菌效果最佳的优化培养基.结果:大肠杆菌培养24h时,纳豆菌上清液对其抑菌达到最强并趋于稳定.获得纳豆菌优化培养基:乳糖2%,蛋白胨4%,Na2HPO4 0.2%,L-赖氨酸0.2%.结论:纳豆菌对致病性大肠杆菌抑制作用较强,为其作为微生态制剂提供一定理论依据.     

影响纳豆激酶酶促反应速度因素的研究

利用分光光度法对由纳豆菌发酵产生的纳豆激酶 (NK)进行了动力学性质的研究。以双倒数作图法 (L -B作图法 )求取Km。采用单因素试验法和正交试验法研究了底物浓度、酶浓度、温度、pH值对酶促反应速度的影响。结果表明该纳豆激酶的Km值为 3.4 98× 1 0 -6g·mL-1 ,当水解时间为 1 0min时 ,最适底物浓度为 1 6mg·mL-1 ,最适温度为 6 0℃ ,最适 pH为 8.0。     

纳豆激酶的研究与应用

纳豆激酶的研究与应用付利,杨志兴（黑龙江省科学院应用微生物研究所）纳豆为日本的传统发酵大豆食品,已食用了２０００年以上。它是由枯草杆菌（ＢａｃｉｌｌｕｓＳｕｂｔｉｌｉｓ）或纳豆菌（Ｂａｃｉｌｌｕｓｎａｔｔｏ）发酵大豆制造成的,日本民众十分喜欢食用。同时也被用作民间药品,以预防和治疗心脑血管性疾病。     

纳豆菌发酵制作鱼内脏有机肥与抑制立枯丝核菌的应用

为了探索纳豆菌有机肥对作物的生长作用及其提高作物对茎基腐病原菌-立枯丝核菌的抗性能力,以纳豆菌作为发酵菌兼功能菌制作鱼内脏有机肥,将成品有机肥进行作物对立枯丝核菌的抗性应用实验:将番茄和辣椒种子播种于感染立枯丝核菌的园土及原园土中,对比植株在两种园土中的生长情况,并进行纳豆菌与立枯丝核菌平板对峙培养试验。结果发现,成品有机肥对两种种子发芽的作用都不明显,两种作物在两种园土中加肥组的植株生长量均达到无肥组的3倍左右,染菌园土中不加肥的番茄和辣椒苗茎基腐病苗率分别是55%和50%,加肥组的番茄和辣椒苗茎基腐病苗率分别是11%和17%;平板对峙培养的菌落状况显示立枯丝核菌生长受到抑制。结果表明,纳豆菌对立枯丝核菌生长具有抑制作用,用纳豆菌发酵制作的有机肥提高番茄和辣椒的生长量,并减少这两种作物的茎基腐病苗率。     

1株纳豆菌抑菌活性及其培养基优化

对1株纳豆菌的体外抑制金黄色葡萄球菌作用进行动力学分析,考察了其培养基组成对纳豆菌增长倍数及抑菌效果的影响,通过正交试验确定纳豆菌对金黄色葡萄球菌起抑菌作用的优化培养基组合为乳糖2%,蛋白胨4%,KH2PO40.2%,甘氨酸0.2%。     

Solid-state production of polygalacturonase by Aspergillus sojae ATCC 20235

The effect of solid substrates, inoculum and incubation time were studied using response surface methodology (RSM) for the production of polygalacturonase enzyme and spores in solid-state fermentation using Aspergillus sojae ATCC 20235. Two-stage optimization procedure was applied using D-optimal and face-centered central composite design (CCD). Crushed maize was chosen as the solid substrate, for maximum polygalacturonase enzyme activity based on D-optimal design. Inoculum and incubation time were determined to have significant effect on enzyme activity and total spore (p<0.01) based on the results of CCD. A second order polynomial regression model was fitted and was found adequate for individual responses. All two models provided an adequate R(2) of 0.9963 (polygalacturonase) and 0.9806 (spores) (p<0.001). The individual optimum values of inoculum and incubation time for maximum production of the two responses were 2 x 10(7) total spores and 5-6 days. The predicted enzyme activity (30.55 U/g solid) and spore count (2.23 x 10(7)spore/ml) were very close to the actual values obtained experimentally (29.093 U/g solid and 2.31 x 10(7)spore/ml, respectively). The overall optimum region considering the two responses together, overlayed with the individual optima. Solid-state fermentation provided 48% more polygalacturonase activity compared to submerged fermentation under individually optimized conditions.     

Effects of gas periodic stimulation on key enzyme activity in gas double-dynamic solid state fermentation (GDD-SSF)

The heat and mass transfer have been proved to be the important factors in air pressure pulsation for cellulase production. However, as process of enzyme secretion, the cellulase formation has not been studied in the view of microorganism metabolism and metabolic key enzyme activity under air pressure pulsation condition. Two fermentation methods in ATPase activity, cellulase productivity, weight lose rate and membrane permeability were systematically compared. Results indicated that gas double-dynamic solid state fermentation had no obviously effect on cell membrane permeability. However, the relation between ATPase activity and weight loss rate was linearly dependent with r = 0.9784. Meanwhile, the results also implied that gas periodic stimulation had apparently strengthened microbial metabolism through increasing ATPase activity during gas double-dynamic solid state fermentation, resulting in motivating the production of cellulase by Trichoderma reesei YG3. Therefore, the increase of ATPase activity would be another crucial factor to strengthen fermentation process for cellulase production under gas double-dynamic solid state fermentation.     

Production of Aspergillus terreus alpha-L-rhamnosidase by solid state fermentation

AIMS: The study of production of Aspergillus terreus CECT 2663 alpha-L-rhamnosidase in solid state fermentation using wheat bran, washed sugar cane bagasse and polyurethane foam as substrates or supports for the enzyme production. METHODS AND RESULTS: Cultures were carried out in Petri dishes under controlled temperature and humidity. Naringin or rhamnose were the enzyme inducers and carbon sources. The enzyme activity to inducer ratio was appreciably greater when using sugar cane bagasse or polyurethane foam than wheat bran. The influence of inoculum size, inducer, airflow, humidity and temperature were determined. Under optimum conditions, about four units of enzyme per ml nutrient solution were obtained after 4-6 d. CONCLUSIONS: The activity to inducer ratio was higher, and the cultivation time was shorter in solid state fermentation than those observed in submerged cultures. SIGNIFICANCE AND IMPACT OF THE STUDY: Solid cultures, using naringin as inducer, can be appropriate alpha-L-rhamnosidase production.     

木霉菌株T6木聚糖酶固态发酵条件和酶学性质研究*

研究了碳源和氮源、起始pH、接种量及温度等条件对一野生型木霉Trichoderma sp.T6菌株固态发酵产木聚糖酶的影响。在28℃培养4d后,酶活力可达1918IU/g干培养物。酶的最适反应温度为50℃,最适反应pH4.5。不同温度保温1h后,测定酶的半失活温度为47.7℃,酶的pH稳定性也进行了研究。     

木霉菌株T6木聚糖酶固态发酵条件和酶学性质研究

研究了碳源和氮源、起始pH、接种量及温度等条件对一野生型木霉Trichoderma sp.T6菌株固态发酵产木聚糖酶的影响。在28℃培养4d后,酶活力可达1918IU/g干培养物。酶的最适反应温度为50℃,最适反应pH4.5。不同温度保温1h后,测定酶的半失活温度为47.7℃,酶的pH稳定性也进行了研究。     

Solid state fermentation of rice chaff for fibrinolytic enzyme production by Fusarium oxysporum

Rice chaff was used as the substrate for the production of fibrinolytic enzyme by Fusarium oxysporum in solid state fermentation. The optimized moisture content of the medium was 30 - 50% (v/w). An inoculum of 5 - 10% (v/v) and an average particle size of 400 μm for the substrate were optimum for productivity and enzyme activity of 80 IU per ml filtrate was achieved after 96 hours of fermentation. This revised version was published online in November 2006 with corrections to the Cover Date.     

Production of pectinesterase and polygalacturonase by Aspergillus niger in submerged and solid state systems

Production of pectinesterase and polygalacturonase by Aspergillus niger was studied in submerged and solid-state fermentation systems. With pectin as a sole carbon source, pectinesterase and polygalacturonase production were four and six times higher respectively in a solid state system than in a submerged fermentation system and required a shorter time for enzyme production. The addition of glucose increased pectinesterase and polygalacturonase production in the solid state system but in submerged fermentation the production was markedly inhibited. A comparison of enzyme productivities showed that those determined for pectinesterase and polygalacturonase with pectin as a carbon source were three and five times higher by using the solid state rather than the submerged fermentation system. The productivities of the two enzymes were affected by glucose in both fermentation systems. The membranes of cells from the solid state fermentation showed increased levels of C18:1, C16:0 and C18:0 fatty acids. Differences in the regulation of enzyme synthesis by Aspergillus niger depended on the fermentation system, favoring the solid state over the submerged fermentation for pectinase production. Received 12 May 1997/ Accepted in revised form 19 September 1997     

Regulation of alpha-amylase production inBacillus licheniformis M27 by enzyme end-products in submerged fermentation and its overcoming in solid state fermentation system

Summary Alpha-amylase production byBacillus licheniformis M27 in submerged fermentation was reduced from 480 to 30 units/ml when soluble starch concentration in medium was increased from 0.2 to 1.0%. In contrast, the enzyme production increased by 29 times even with 42 fold increase in the concentration of soluble starch and other starchy substrates in solid state fermentation system. The data establish regulation of the enzyme formation by enzyme end-product in submerged fermentation and ability of solid state fermentation to minimize it significantly. These features were not known earlier.     

Cellulase production by solid state fermentation on lignocellulosic waste from the xylose industry

Cellulase production was carried out by solid state fermentation using corncob residue, a lignocellulosic waste from the xylose industry, as the substrate of Trichoderma reesei ZU-02. The effects of water content, dosage of wheat bran and initial pH value in solid substrate on cellulase synthesis were studied in shallow tray fermentors. The solid substrate could be reused in at least three batches and the highest cellulase activity (158 IFPU/g koji) was obtained in the second fermentation batch. To produce cellulase on a larger scale, a deep trough fermentor with forced aeration was used and 128 IFPU/g koji (305 IFPU/g cellulose) was reached after 5 days solid state fermentation. The enzyme koji produced in the present process can be used directly to hydrolyze corncob residue effectively, when the cellulase dosage was above 20 IFPU/g substrate, the saccharification yield could be over 84%.     

固态发酵的参数周期变化及对微生物发酵的影响

研究了压力脉动固态发酵反应器内环境参数的周期性变化以及这些周期性的环境刺激对于固态培养的斜卧青霉发酵的影响。研究结果显示:在这种反应器中,在空气压力脉动的带动下,反应器内的温度和空气湿度也会发生较大幅度的周期性变化,变化的周期和空气压力脉动的周期相同,变化的幅度随着压力脉动的幅度增大而增加;在外界周期刺激的条件下,较未加外界周期刺激斜卧青霉的生物量增加了104% ,二氧化碳的产生总量增加了229%和纤维素酶的产量增加了320 % ,数据显示外界周期刺激不仅增加了菌体的生物量同时增加了其代谢活性。