共查询到20条相似文献，搜索用时 180 毫秒
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本研究采用逐量分批驯化的方法,从造纸废水中分离得到一株能够以苯酚为唯一碳源生长的苯酚降解菌株F5-1。经形态观察、生理生化特性鉴定及16S rDNA序列分析,将该菌株鉴定为克雷伯菌（Klebsiella sp.）。该菌株能够在7h时完全降解初始浓度为100mg/L的苯酚,降解苯酚主要发生在生长对数期;在pH5.0～9.0,NaCl浓度0～80g/L,温度20～40℃范围内,菌株F5-1均可有效降解初始浓度为100～1200mg/L的苯酚;能够耐受的最大苯酚浓度为1500mg/L。本研究结果表明,F5-1菌株对处理环境条件复杂的含酚废水具有潜在的应用前景。 相似文献
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提高猪场沼液净化处理效果的氨吹脱控制参数 总被引：7，自引：5，他引：2
针对畜禽养殖场沼气工程沼液氨氮浓度高,碳氮比不足,直接采用传统生化污水处理法效果不佳的问题,该文对氨吹脱工艺降低猪场沼液氨氮浓度参数进行了试验研究,探索了不同初始氨氮浓度、pH值、气液比、温度等参数对氨氮去除的效果,并进一步研究了Ca(OH)2的混凝作用。结果表明:初始氨氮质量浓度分别为500和900mg/L时,氨氮去除率无显著差异。在初始氨氮质量浓度为900mg/L,pH值为10.5,气液比(流量比)2000,沼液温度30℃的运行条件下,氨氮去除率较高为81.84%。在Ca(OH)2投加量为5.0g/L条件下,混凝沉淀效果较好,化学需氧量(COD)、总磷(TP)和PO43-去除率分别为30.13%、97.44%和98.76%,但总硬度提高了106%。该文研究结果为开发沼液深度处理工艺提供了数据。 相似文献
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以菊芋粉为原料同步糖化发酵生产燃料乙醇 总被引：4，自引：1，他引：3
利用粟酒裂殖酵母（Schizosaccharomyces pombe）能发酵菊芋未水解糖液高产乙醇的特点提出了以菊芋粉为原料,同步糖化发酵生产燃料乙醇的新工艺。在摇瓶中考察了原料预处理方法、原料浓度和初始pH值对乙醇发酵的影响,进而在5 L发酵罐中考察了未调控pH值和恒定pH值与通气情况对乙醇发酵的影响。结果表明：该菌株最适pH值为4.0;100目筛分的菊芋粉发酵效果良好,115℃灭菌处理优于121℃,在此条件下,菊芋粉浓度200 g/L时,乙醇产量达到66.58 g/L,理论转化率为85.88%;发酵液pH值下降对乙醇发酵没有影响,通入适量氧气会导致乙醇产量的下降,这表明粟酒裂殖酵母进行乙醇发酵时不需要供氧;通入氮气保持厌氧环境不能显著提高乙醇产量,不通气进行乙醇发酵也达到高的转化率,因此在工业生产中,不必保持厌氧发酵环境。在此基础上,对菊芋粉补料发酵进行了试验,补料至菊芋粉终浓度为300 g/L,发酵终点乙醇浓度为94.81 g/L,理论转化率为81.54%。这些研究工作,为以菊芋为原料的燃料乙醇工业化生产提供技术依据。 相似文献
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水汽相变技术与湿法烟气脱硫系统(wet flue gas desulfurization,WFGD)结合可有效控制细颗粒物排放,脱硫净烟气所能达到的过饱和度直接影响细颗粒物脱除效果,而烟气过饱和度取决于脱硫净烟气温湿度和水蒸气添加量。因而脱硫净烟气温湿度变化特性研究可为WFGD系统中应用水汽相变促进细颗粒物脱除提供依据,对于优化湿法脱硫操作条件、估算水蒸气添加量以及实现低能耗高效脱除细颗粒物具有重要意义。该文基于石灰石-石膏法脱硫工艺,试验考察了脱硫塔进口烟气温湿度、空塔气速、液气比、脱硫液温度等操作条件以及脱硫塔类型对脱硫净烟气温湿度的影响。结果表明,空塔气速由2.5 m/s提高至2.9 m/s可使脱硫净烟气相对湿度和绝对湿度分别由88%、82.2 g/kg先急剧降低至52%、57.3 g/kg,随后趋于相对平缓;液气比由5 L/m~3增至20 L/m~3有利于提高脱硫净烟气的相对湿度和绝对湿度,可分别由39%、46.4 g/kg提高至91%、84.3 g/kg,但相对湿度的增幅明显高于绝对湿度增幅;脱硫净烟气的相对湿度、绝对湿度及温度均随脱硫液温度升高而迅速提高,液气比为15 L/m3时,脱硫液温度由25℃升至60℃可使脱硫净烟气相对湿度、绝对湿度、温度分别由54%、25.9 g/kg、42℃提高至85%、98.5 g/kg、56℃,但脱硫液温度升至40℃后,脱硫净烟气的相对湿度趋于平缓;脱硫液温度保持不变时,提高塔进口烟气温度可使脱硫净烟气的绝对湿度和温度先明显增加,随后趋于平缓,而相对湿度随塔进口烟温提高稍有降低;并且不同的脱硫塔型对脱硫净烟气温湿度也有影响,液气比为5 L/m3时,经湍球塔、旋流板塔、喷淋塔脱硫后的净烟气相对湿度分别为90%、91%、44%。该研究结果为湿法烟气脱硫系统的应用提供参考。 相似文献
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光合细菌协同产气肠杆菌联合发酵制氢试验 总被引：1，自引：0，他引：1
暗-光联合生物制氢是提高底物利用率和产氢潜力的有益探索。该文以玉米秸秆酶解液为产氢底物,采用光合细菌(HAU-M1)与产气肠杆菌(AS1.489)混合培养工艺,进行了同步糖化暗-光联合生物制氢试验研究。以累积产氢量为主要指标,利用单因素试验考察了底物质量浓度、初始pH值、光照强度、发酵温度对HAU-M1与产气肠杆菌混合培养条件下联合产氢的影响,并在单因素试验的基础上通过正交试验对产氢工艺参数进行了优化。结果表明:各工艺参数对HAU-M1与产气肠杆菌联合产氢影响的主次顺序为:发酵温度初始pH值底物质量浓度光照强度。发酵温度和初始pH值是影响HAU-M1与产气肠杆菌联合产氢的显著因素。HAU-M1与产气肠杆菌混合培养联合产氢的较佳工艺条件为:底物质量浓度35 g/L、初始pH值6.5、光照强度3 500 1x、发酵温度30℃,在此条件下,72 h的累积产氢量达到332.6 mL,单位产氢量为47.5 mL/g。该试验研究可为基于秸秆类生物质的暗-光细菌混合培养联合产氢的进一步研究提供参考。 相似文献
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对L-色氨酸生产基因工程菌TP01发酵的接种量、发酵温度和溶氧等条件进行了研究。结果表明,该菌株的最佳发酵条件初始培养基组成为葡萄糖30 g/L、硫酸铵40 g/L、酪氨酸0.2 g/L、玉米浆25 mL/L、磷酸氢二钾10 g/L、磷酸二氢钾5 g/L、七水硫酸镁2 g/L、硫酸钠0.002 g/L、七水硫酸亚铁0.01 g/L、维生素B1 100 μg/L、维生素H 50 μg/L,流加糖为浓度70%的葡萄糖(质量体积比),pH为7.0,温度为37 ℃,接种量为10%,溶氧控制在20%~30%。 相似文献
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利用小麦/玉米秸秆还田土壤样品,通过富集培养和刚果红平板染色法筛选分离出纤维素降解细菌XWS-12;对分离的菌株进行16S rRNA基因序列系统发育分析,初步鉴定为伯克氏菌属(Burkholderia),定名为Burkholderia sp.XWS-12。以玉米秸秆和麸皮为碳源,研究了氮源、发酵时间、初始发酵温度、培养基初始pH等条件对该伯克氏菌产纤维素酶的影响。结果显示,该菌株产纤维素酶最适氮源为硝酸钠,培养时间为60 h,培养温度为37℃,培养基初始pH为4,该菌株的CMC酶活力最高,可达25 U/ml。其粗酶液的最适反应温度为50℃,最适反应pH为5,在pH 4~8的范围内酶活力较稳定。粗酶液的热稳定较差,当温度超过50℃时,该酶活力显著下降;当温度为50℃时,保温1 h,该酶活力损失53%。 相似文献
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不同种类大豆蛋白粉对面包加工特性的影响 总被引：6，自引：2，他引：6
为探索大豆蛋白作为营养补充剂在面包中应用时，对面团物理特性和焙烤特性产生的影响，该文考察了不同种类的大豆蛋白制品，包括大豆分离蛋白、灭酶全脂粉、活性全脂粉、活性脱脂粉、灭酶脱脂粉对面团粉质特性、拉伸特性和焙烤特性的影响。结果表明，面粉的吸水率与大豆蛋白粉氮溶解指数显著相关，面团的抗拉阻力受大豆蛋白添加量的影响明显。大豆蛋白粉的加入，对面包比体积产生不利影响，下降趋势与大豆蛋白粉对面团拉伸特性的影响显著相关。大豆蛋白粉有软化面包质地的作用，活性全脂粉表现最为明显。大豆蛋白粉的加入量占面粉质量分数的3%时，对面包口感影响不明显，当加入量超过面粉质量分数的7％时，容易出现发粘和豆腥味等现象。 相似文献
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The rheological properties of tomato juice containing 1.5% soy germ were compared to plain tomato juice with and without soy protein isolate. This novel product was developed to provide a delivery system of carotenoids, soy protein, and significant isoflavone content without compromising the perceived juice characteristics of tomato product. Rheological tests depicted physical gel characteristics for all three products. Dynamic tests as a function of temperature showed that the stability and the compatibility between tomato juice and soy germ were higher as compared to soy protein isolate. The hydrophobic and electrostatic interactions between pectin and protein in the tomato soy protein isolate system were weakened as the temperature was increased. In the case of tomato juice with soy germ, the viscosity did not change during heating. The addition of soy germ increased the viscosity of tomato juice reinforcing the entire system without major qualitative effects on the rheological properties of plain tomato juice. 相似文献
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D B Berkowitz D W Webert 《Journal of the Association of Official Analytical Chemists》1987,70(1):85-90
A number of methods may be used for determining soy flour in meat products. Highly purified soy products are more difficult to determine because the nonprotein components used to quantify the flour are reduced. Immunoassays have been used to directly measure protein content of soy products. Immunological methods for determination of soy proteins in meat are complicated by changes in the structure of the soy proteins during processing. These changes alter the available epitopes, changing the immunoreactivity of soy proteins. The epitopes available are dictated by the details of the processing. Other workers circumvented this problem by denaturing the soy protein with urea and mercaptoethanol, and then removing these agents by dialysis; whatever the initial protein conformation, all soy samples came to the same final conformation after the denaturing agents were removed. The assay used antibody made against the "renatured protein." These steps made the assay long and laborious. Attempts to develop a rapid assay were complicated by the same protein denaturation problems. Sodium dodecylsulfate gel electrophoresis coupled with immunoblotting may be the best quantitative approach. 相似文献
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Martín-Hernández C Bénet S Marvin-Guy LF 《Journal of agricultural and food chemistry》2005,53(22):8607-8613
Several methods for extraction and quantification of proteins from lecithins were compared. Extraction with hexane-2-propanol-water followed by amino acid analysis is the most suitable method for isolation and quantification of proteins from lecithins. The detection limit of the method is 15 mg protein/kg lecithin, and the quantification limit is 50 mg protein/kg. The relative repeatability limits for samples containing 0-500 and 500-5000 mg protein/kg sample were 12.6 and 7.5%, respectively. The protein recovery ranged between 101 and 123%. The protein content has been determined in different kinds of lecithins. The results were as follows: standard soy lecithins (between 232 and 1338 mg/kg), deoiled soy lecithin (342 mg/kg), phosphatydylcholine-enriched soy lecithins (not detectable and 163 mg/kg), sunflower lecithins (892 and 414 mg/kg), and egg lecithin (50 mg/kg). The sodium dodecyl sulfate-polyacrylamide gel electrophoresis protein patterns of the standard soy and sunflower lecithins are very similar to those of soy flour. The protein profile of the egg lecithin shows several bands with a broad range of molecular masses. The molecular masses of the main proteins of soy lecithins and soy flour have been determined by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) and ranged from 10.5 to 52.2 kDa. Most of the major proteins from soy and sunflower lecithins identified by MALDI-MS and electrospray tandem MS belong to the 11S globulin fraction, which is one of the main fractions of soy and sunflower seeds. In addition, the seed maturation protein P34 from the 7S globulin fraction of soy proteins has also been identified in soy lecithins. This protein has been reported as the most allergenic protein in soybean. 相似文献
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The Kunitz trypsin inhibitor (KTI) and the Bowman-Birk inhibitor (BBI) of trypsin and chymotrypsin contain disulfide bonds. Glycinin, the major storage protein in soybeans also contains disulfide bonds. Treatment of soy white flour with a NADP-thioredoxin system (NTS) effectively reduced disulfide bonds in soy flour and increased protein digestibility by trypsin and pancreatin as measured by the pH stat method. Treatment of soy flour with NTS increased the digestibility compared to soy white flour by 29.3 and 60.6% for trypsin and pancreatin, respectively. NTS-treated soy flour had similar digestibility by trypsin to autoclaved soy flour and casein, but digestibility by pancreatin was less than autoclaved soy flour and casein. The degree of reduction by NTS was highly correlated to the degree of hydrolysis (DH) by trypsin (R(2) = 0.93) and pancreatin (R(2) = 0.99). The DH of NTS-treated soy flour by trypsin is reflective of both inactivation of trypsin inhibitors and overall protein digestibility while pancreatin hydrolysis is reflective of only overall protein digestibility. 相似文献
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The aggregation behavior during heating of a solution containing soy protein and whey protein isolate (WPI) was studied using rheology, confocal microscopy, gel filtration, and electrophoresis. Soy/WPI mixtures formed gels at 6% total protein concentration with a high elastic modulus (G') and no apparent phase separation. The ratio of soy to WPI was fundamental in determining the type of network formed. Systems containing a high soy to WPI ratio (>70% soy protein) showed a different evolution of the elastic modulus during heat treatment, with two apparent stages of network development. Whey proteins formed disulfide bridges with soy proteins during heating, and at low ratios of soy/WPI, the aggregates seemed to be predominantly formed by 7S, the basic subunits of 11S and beta-lactoglobulin. Size exclusion chromatography indicated the presence of high molecular weight soluble complexes in mixtures containing high soy/WPI ratios. Results presented are the first evidence of interactions between soy proteins and whey proteins and show the potential for the creation of a new group of functional ingredients. 相似文献
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K. J. Ryan C. L. Homco‐Ryan J. Jenson K. L. Robbins C. Prestat M. S. Brewer 《Cereal Chemistry》2002,79(3):434-438
Protein‐protein interactions between wheat flour and solvent‐extracted (SE) or nonsolvent extracted (NSE) texturized soy flours were compared. Doughs were prepared to contain varying ratios of texturized soy flour in combination with wheat flour. Sucrose esters (2.5%) were included in several formulations. Doughs were fractionated into soluble and insoluble fractions at pH 4.7 and pH 6.1. Fractions were dried, powdered, and analyzed using SDS‐PAGE and spectrophotometric techniques. Electrophoretic evaluation indicated interactions between wheat gluten proteins and texturized soy proteins in the absence of sucrose esters. Electrophoretic gels of the wheat‐soy flour mixtures maintained a characteristic soy protein band after acidification to the soy protein isoelectric point. Inclusion of sucrose esters increased the interaction. Texturization conferred effects similar to that of sucrose ester on both forms of lipid‐extracted soy. Sulfhydryl analyses using 7‐chloro‐4‐nitrobenzo‐2‐oxa‐4, 3‐diazole (NBD‐Cl) revealed no change in the relative amount of sulfhydryl groups present in doughs prepared from either the texturized soy flours or the doughs containing equal amounts of wheat starch. These data indicate that interactions between soy protein from texturized soy flours and wheat proteins are not covalent. 相似文献
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A protein-binding technique was employed to visualize, using scanning electron microscopy, the soy protein as well as the association between HMP and soy protein fractions. Image analysis indicated that at pH 7.5 and 3.5 soy protein isolate showed a bimodal distribution of sizes with an average [ d(0.5)] of about 0.05 microm, but at pH 3.8 the proteins formed larger aggregates than at high pH. Addition of HMP at pH 3.8 changed the surface charge of the particles from +20 to -15 mV. A small addition of HMP caused bridging of the pectin between soy protein aggregates and destabilization. With sufficient HMP, the suspensions showed improved stability to precipitation. The microscopy images are the first direct evidence of the interactions between soy proteins with high-methoxyl pectin (HMP). 相似文献
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不同工艺生产大豆分离蛋白的成膜性能 总被引：5，自引：1，他引：4
为了制作出具有良好机械性和阻隔性的大豆分离蛋白可食性膜,优选出成膜性能优良的大豆分离蛋白,该文研究了7种不同生产工艺下的大豆分离蛋白,分别以7种蛋白为材料制膜,测定其机械性能、水溶性、水蒸气透过性、O2透过性、脂质渗透性等性能,进行模糊综合评价,并用扫描电镜观察膜的表面结构。结果表明:GS5000型普通型未经造粒的大豆分离蛋白综合评价分数最高,表明其成膜性能优于其他6种大豆分离蛋白,并且电镜扫描照片也显示用其制出的膜结构更加致密,因此,GS5000型大豆分离蛋白比较适合制作可食性膜。该研究为进一步开发优质大豆分离蛋白膜进行了初步的探索。 相似文献