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Cloning,characterization and expression analysis of a microsomal glutathione S-transferase gene from the seagrass Zostera marina 预览
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作者 Wenjie Yan Jiao Liu +2 位作者 Samphal Seng Bin Zhou Kuke Ding 《海洋学报:英文版》 SCIE CAS CSCD 2019年第10期111-115,共5页
The response of glutathione S-transferase(GST)in Zostera marina to temperature variation was analyzed at molecular level by cloning the microsomal GST gene and texting the microsomal GST expression regularity under di... The response of glutathione S-transferase(GST)in Zostera marina to temperature variation was analyzed at molecular level by cloning the microsomal GST gene and texting the microsomal GST expression regularity under different temperature.Specific speaking,express ZmGST in Escherichia coli,then purify the recombinant protein and make the thermal stability analysis.Therefore,the experiments were carried out to provide a theoretical basis for the further elaboration to the population degradation mechanisms of Z.marina.In conclusion,the thermostability and the response of ZmGST gene to temperature changes can determine its temperature tolerance range,and affect its resilience in turn. 展开更多
关键词 ZOSTERA MARINA antioxidant ENZYME GLUTATHIONE S-TRANSFERASE (GST) temperature ENZYME activity
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Effects of Nicotine, a Plant Secondary Metabolite, on Protective Enzyme and Detoxification Enzyme of Frankliniella occidentalis 预览
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作者 Liu Jiani Su Yuan +3 位作者 Wei Wei Zhong Yu Chen Zebin Yu Lei 《Plant Diseases and Pests(植物病虫害研究:英文版)》 CAS 2019年第2期7-10,共4页
[Objective] The paper was to explore the effects of plant secondary metabolite on protective enzymes and detoxification enzymes of quarantine pest Frankliniella occidentalis.[Method] F.occidentalis were continuously e... [Objective] The paper was to explore the effects of plant secondary metabolite on protective enzymes and detoxification enzymes of quarantine pest Frankliniella occidentalis.[Method] F.occidentalis were continuously exposed to artificial diets containing nicotine from the second to fifth instars for five generations, and the effects of nicotine on protective enzymes and detoxification enzymes of larvae were determined.[Result] The activities of carboxylate esterase (CarE) and glutathione-S-transferase (GST) in midgut of the fifth instar larvae were significantly increased, and reached the maximum at the third generation (1.86 times and 1.59 times, respectively). Nicotine inhibited the activities of superoxide dismutase (SOD) and catalase (CAT). With the increase of feeding generations, the inhibitory effect of nicotine weakened. Nicotine significantly increased the activities of peroxidase (POD).[Conclusion] F. occidentalis will gradually adapt to the harm of plant toxins by starting its own detoxification enzyme system and regulating protective enzyme system after feeding on plant secondary substance nicotine. 展开更多
关键词 NICOTINE FRANKLINIELLA OCCIDENTALIS DETOXIFICATION ENZYME Protective ENZYME
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Predicting pH Optimum for Activity of Beta-Glucosidases 预览
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作者 Shaomin Yan Guang Wu 《生物医学工程(英文)》 2019年第7期354-367,共14页
The working conditions for enzymatic reaction are elegant, but not many optimal conditions are documented in literatures. For newly mutated and newly found enzymes, the optimal working conditions can only be extrapola... The working conditions for enzymatic reaction are elegant, but not many optimal conditions are documented in literatures. For newly mutated and newly found enzymes, the optimal working conditions can only be extrapolated from our previous experience. Therefore a question raised here is whether we can use the knowledge on enzyme structure to predict the optimal working conditions. Although working conditions for enzymes can be easily measured in experiments, the predictions of working conditions for enzymes are still important because they can minimize the experimental cost and time. In this study, we develop a 20-1 feedforward backpropagation neural network with information on amino acid sequence to predict the pH optimum for the activity of beta-glucosidase, because this enzyme has drawn much attention for its role in bio-fuel industries. Among 25 features of amino acids being screened, the results show that 11 features can be used as predictors in this model and the amino-acid distribution probability is the best in predicting the pH optimum for the activity of beta-glucosidases. Our study paves the way for predicting the optimal working conditions of enzymes based on the amino-acid features. 展开更多
关键词 BETA-GLUCOSIDASE ENZYME PH OPTIMUM PREDICTION
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影响多步脱氢酶CrtI功能的关键结构特征探索 预览
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作者 陈琛 王颖 +3 位作者 刘宏 陈艳 姚明东 肖文海 《化工学报》 EI CAS CSCD 北大核心 2019年第1期189-198,共10页
在生物体内存在可催化多步连续反应的通用酶,对生物代谢过程具有重要作用。八氢番茄红素脱氢酶(CrtI)作为典型代表,可以催化多步连续脱氢反应,生成番茄红素等具有重要价值的产物。本文以酿酒酵母为底盘研究CrtI的催化功能特征。首先通... 在生物体内存在可催化多步连续反应的通用酶,对生物代谢过程具有重要作用。八氢番茄红素脱氢酶(CrtI)作为典型代表,可以催化多步连续脱氢反应,生成番茄红素等具有重要价值的产物。本文以酿酒酵母为底盘研究CrtI的催化功能特征。首先通过组合设计与筛选番茄红素合成路径中的三种外源酶CrtE、CrtB和CrtI,发现CrtI是主要的限制因素,且三孢布拉氏霉菌来源的CrtI(BtCrtI)表现出优异的催化功能。通过生物信息学与蛋白结构分析发现BtCrtI的S311残基是连接和稳定活性中心结构的关键。随后通过分析该位点的饱和突变结果,揭示了该位点的氨基酸残基类型对活性中心结构和功能的显著作用,为酶的设计和改造提供了新的思路。同时发现CrtI的活性差异未对合成路径中的类胡萝卜素的代谢流造成扰动,表明CrtI是番茄红素的产量和纯度的决定因素. 展开更多
关键词 合成生物学 生物催化 八氢番茄红素脱氢酶 多步脱氢反应 酶的活性中心结构
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低温等离子体预处理酶对苎麻织物的脱胶研究 预览
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作者 汤云高 祁丽 龙家杰 《纺织科学与工程学报》 CAS 2019年第3期52-58,共7页
将低温等离子体预处理后的脱胶酶用于苎麻织物的脱胶前处理,对其主要影响因素进行了探讨,并通过正交试验和配方试验进行了优化。结果表明,低温等离子预处理酶种类对苎麻织物的脱胶失重率、毛效、白度有非常显著的影响,而脱胶处理时间对... 将低温等离子体预处理后的脱胶酶用于苎麻织物的脱胶前处理,对其主要影响因素进行了探讨,并通过正交试验和配方试验进行了优化。结果表明,低温等离子预处理酶种类对苎麻织物的脱胶失重率、毛效、白度有非常显著的影响,而脱胶处理时间对织物失重率有显著的影响,脱胶温度则对织物白度有显著影响;但溶液pH值及其他工艺因素,以及因素间的交互作用对脱胶效果影响不显著;经正交试验优选后的推荐脱胶工艺为:脱胶温度为55.0℃,溶液pH为4.0,处理时间为100.0min;配方试验显示,经低温等离子体预处理后的混合生物酶,以脱胶失重率为指标的最佳比例为木聚糖酶:果胶酶=0.57:0.43,混合酶总用量为8.0%(o.m.f)。实验同时表明,低温等离子体预处理脱胶酶对苎麻织物的脱胶效率得到显著改善。 展开更多
关键词 苎麻织物 生物酶 脱胶 低温等离子体 预处理酶
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辣椒酵素益生菌复合发酵制剂的筛选 预览
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作者 孙树平 刘志伟 +1 位作者 李京 何丽丽 《食品与机械》 北大核心 2019年第8期189-194,199共7页
以前期试验筛选出的植物乳杆菌、酿酒酵母、醋酸菌为研究对象,从中选择2组益生菌复合发酵剂L1(植物乳杆菌和酿酒酵母)、L2(植物乳杆菌、酿酒酵母和醋酸菌)制作辣椒酵素,并与传统自然发酵L0做对比。通过观察发酵过程中总酸、pH值、酒精... 以前期试验筛选出的植物乳杆菌、酿酒酵母、醋酸菌为研究对象,从中选择2组益生菌复合发酵剂L1(植物乳杆菌和酿酒酵母)、L2(植物乳杆菌、酿酒酵母和醋酸菌)制作辣椒酵素,并与传统自然发酵L0做对比。通过观察发酵过程中总酸、pH值、酒精度以及主要功效酶活力(超氧化物歧化酶活力、脂肪酶活力)等主要质量指标的变化规律,筛选出最适合辣椒酵素发酵的一种菌种组合。试验结果表明:混菌发酵对辣椒酵素的品质有明显的改善。发酵第15天,L1、L2与L0相比,总酸含量分别提高了36.53%,31.42%;脂肪酶活力分别提高了99.22%,96.27%;SOD活力分别提高了6.93%,0.91%;pH值分别降低了10.35%,11.05%。此时L1的感官评分最高为(88.75±0.88),总酸含量为34.82g/L,酒精含量为0.023g/L,pH值为3.75,SOD酶活力为88.71U/mL,脂肪酶活力45.75U/L,明显优于L2。植物乳杆菌和酿酒酵母复合的发酵剂适用于辣椒酵素的发酵。 展开更多
关键词 辣椒 植物乳杆菌 酿酒酵母 酵素 酶活力 总酸
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Predictors for Predicting Temperature Optimum in Beta-Glucosidases 预览
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作者 Shaomin Yan Guang Wu 《生物医学工程(英文)》 2019年第8期414-426,共13页
This is the continuation of our studies on beta-glucosidase, which plays an important role in biological processes and recently strong interests focus on their potential role in biofeul production. In order to develop... This is the continuation of our studies on beta-glucosidase, which plays an important role in biological processes and recently strong interests focus on their potential role in biofeul production. In order to develop simple methods to predict the optimal working condition for beta-glucosidase, we used a 20-1 feedforward backpropagation neural network to screen possible predictors to predict the temperature optimum of beta-glucosidase from 25 amino-acid properties related to the primary structure of beta-glucosidases. The results show that the normalized polarizability index and amino-acid distribution probability can predict the temperature optimum of beta-glucosidase, which highlights a cost-effective way to predict various enzymatic parameters of beta-glucosidase. 展开更多
关键词 BETA-GLUCOSIDASE ENZYME TEMPERATURE OPTIMUM PREDICTION
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Effects of Processing on Antioxidant Capacity and Metabolizing Enzyme Inhibition of Tiger Nut Tubers 预览
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作者 Shantrell Willis Cydney Jackson Martha Verghese 《食品与营养科学(英文)》 2019年第9期1132-1141,共10页
Tiger nut (Cyperus esculentus), commonly referred to as chufa, is a “nut-like” tuber, native to tropical and Mediterranean regions. It is often consumed in the form of a beverage (horchata de chufa). Health benefits... Tiger nut (Cyperus esculentus), commonly referred to as chufa, is a “nut-like” tuber, native to tropical and Mediterranean regions. It is often consumed in the form of a beverage (horchata de chufa). Health benefits of tiger nut have been attributed to presence of phytochemicals and their antioxidant potential. Tiger nut is often processed in order to enhance sensory characteristics. The objective of study was to determine effects of processing on antioxidant content, potential and inhibition of metabolizing enzyme activities of tiger nuts. Total phenolic content (TPC), total flavonoid content (TFC), free radical scavenging activity by 1,1-diphenyl-2-picryhydrazyl (DPPH), trolox equivalent antioxidant capacity (TEAC), ferric reducing antioxidant power (FRAP) and inhibition of lipase and α-amylase were evaluated in raw tiger nuts extracted with water (TRWA) and methanol (TRWM) and roasted (110&deg;C – 115&deg;C for 10 mins) tiger nuts extracted with water (TRA) and methanol (TRM). Highest phenolic content was observed in TRWA (1186.68 GAE/100g) and TRWM had lowest (43.77 GAE/100g). TRWA also exhibited highest ferric reducing ability with a FRAP value of 169.83 mm Fe2+/100g). TRWM had a higher flavonoid content (220.68 CAE/100g) compared to all other extracts. At a concentration of 0.02 mg/ml, all extracts reached at least 50% inhibition of DPPH, while highest scavenging activity was observed in TRM (58%). Highest TEAC was observed in TRM with 55.66% of ABTS radical scavenged. TRA had a significantly higher ability to inhibit α-amylase and lipase compared to other extracts. Results suggest that processing had an effect on the antioxidant potential of tiger nut, and this tuber may benefit consumers by improving their antioxidant status. 展开更多
关键词 ANTIOXIDANT TUBER ENZYME
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Ionic Liquid-Polypyrrole-Gold Composites as Enhanced Enzyme Immobilization Platforms forHydrogen Peroxide Sensing 预览
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作者 Meng Li Jing Wu +3 位作者 Haiping Su Yazhuo Shang Yifan He Honglai Liu 《北京日化》 2019年第2期15-32,共18页
In this work, three different aqueous solutions containing imidazole-based ILs w让h different alkyl chain lengths ([Cnmim]Br, n = 2Z 6,12) were adopted as the medium for the synthesis of ionic liquid-polypyrrole (IL-P... In this work, three different aqueous solutions containing imidazole-based ILs w让h different alkyl chain lengths ([Cnmim]Br, n = 2Z 6,12) were adopted as the medium for the synthesis of ionic liquid-polypyrrole (IL-PPy) composites. Herein, the ILs undertook the roles of the pyrrole solvent, the media for emulsion polymerization of PPy and PPy dopants, respectively. The electrochemical performances of the three IL-PPy composites on a glassy carbon electrode (GCE) were investigated by electrochemical experiments, which indicated that [Ci2mim]Br-PPy (Ci2~PPy) composites displayed better electrochemical performance due to their larger surface area and firmer immobilization on the GCE. Further, Ci2?PPy/GCE were decorated with Au microparticles by electrodeposition that can not only increase the conductivity, but also immobilize sufficient biomolecules on the electrode. Then, the obtained Ci2~PPy~Au/GCE with outstanding electrochemical performance was employed as a horseradish peroxidase (HRP) immobilization platform to fabricate a novel Ci2-PPy-Au-HRP/GCE biosensor for H2O2 detection. The results showed that the prepared Ci2-PPy-Au-HRP/GCE biosensor exhibited high sensitivity, fast response, and a wide detection range as well as low detection limit towards H2O2. This work not only provides an outstanding biomolecule immobilization matrix for the fabrication of highly sensitive biosensors, but also advances the understanding of the roles of ILs in improving the electrochemical performance of biosensors. 展开更多
关键词 ionic liquids (ILs) POLYPYRROLE (PPy) GOLD particles HORSERADISH PEROXIDASE (HRP) enzyme immobilization hydrogen PEROXIDE sensor
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日立7080酶法检测钠交叉污染的查找和清除 预览
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作者 李伟波 李娟 贾黎方 《检验医学与临床》 CAS 2019年第1期54-56,60共4页
目的探讨日立7080酶法检测钠的交叉污染的清除问题。方法首先通过试验检查样品针是否携带污染,然后通过试验发现试剂间有无交叉污染,进而查找试剂间交叉污染发生的位置,最终采取相应的措施消除交叉污染。结果试剂针被污染时,总胆红素(TB... 目的探讨日立7080酶法检测钠的交叉污染的清除问题。方法首先通过试验检查样品针是否携带污染,然后通过试验发现试剂间有无交叉污染,进而查找试剂间交叉污染发生的位置,最终采取相应的措施消除交叉污染。结果试剂针被污染时,总胆红素(TBIL)和低密度脂蛋白胆固醇(LDL-C)2个项目对酶法检测钠有显著影响。结论生化分析仪试剂针老化导致酶法检测钠发生交叉污染后,只能更换试剂针R1和R2,污染才能彻底消除。 展开更多
关键词 酶法 交叉污染
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糯米发酵酱姜风味酵素饮品配方及工艺优化研究 预览
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作者 朱建华 邹秀容 +4 位作者 刘日斌 黄静梅 林如 古丽容 刘波 《江西农业学报》 CAS 2019年第7期92-97,共6页
采用糯米发酵酱姜提取液为基料,然后以感官评分、可溶性固形物含量及粒度参数为综合指标,在单因素实验的基础上进行正交试验,优化得出糯米发酵酱姜基料风味饮品的最佳配方参数:柠檬酸0.10%(w/w),白砂糖7.0%(w/w),酱姜浸提液基料30%(w/w)... 采用糯米发酵酱姜提取液为基料,然后以感官评分、可溶性固形物含量及粒度参数为综合指标,在单因素实验的基础上进行正交试验,优化得出糯米发酵酱姜基料风味饮品的最佳配方参数:柠檬酸0.10%(w/w),白砂糖7.0%(w/w),酱姜浸提液基料30%(w/w),卡拉胶0.02%(w/w)。在该最优条件下制备的酱姜风味酵素饮品具有最佳的品质和最好的储存稳定性。 展开更多
关键词 糯米 酱姜 酵素 风味饮品 配方优化 粒度
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酿酒小曲中功能微生物的研究进展 预览
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作者 王春晓 唐佳代 +2 位作者 吴鑫颖 周鸿翔 邱树毅 《食品科学》 EI CAS CSCD 北大核心 2019年第17期309-316,共8页
功能微生物的挖掘与应用是近年来酿酒工程领域科学研究与工业生产共同关注的焦点,然而,检索CNKI中国知网和Web of Science数据库发现,近10年关于酒曲中功能微生物的研究有超过400篇文献针对大曲,针对小曲的相关研究报道却不足50篇。本... 功能微生物的挖掘与应用是近年来酿酒工程领域科学研究与工业生产共同关注的焦点,然而,检索CNKI中国知网和Web of Science数据库发现,近10年关于酒曲中功能微生物的研究有超过400篇文献针对大曲,针对小曲的相关研究报道却不足50篇。本文首先介绍了小曲的定义、发展历史和应用现状,然后综述了酿酒小曲中功能微生物在种类、筛选方法、功能成分、应用价值等方面的研究现状,重点阐述了酿酒小曲中功能酵母主要功能产物的代谢机理,为酿酒小曲中功能微生物的进一步研究和工业生产应用提供参考。 展开更多
关键词 酵母 霉菌 细菌 高级醇
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Recovery of Chitin and Protein from Shrimp Head Waste by Endogenous Enzyme Autolysis and Fermentation 预览
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作者 GUO Na SUN Jianan +1 位作者 ZHANG Zhaohui MAO Xiangzhao 《中国海洋大学学报:英文版》 SCIE CAS CSCD 2019年第3期719-726,共8页
The industrial processing of shrimp produces massive quantities of solid waste that is a notable source of animal protein, chitin, carotenoids, and other bioactive compounds that are not appropriately utilized. In the... The industrial processing of shrimp produces massive quantities of solid waste that is a notable source of animal protein, chitin, carotenoids, and other bioactive compounds that are not appropriately utilized. In the present study, chitin and protein extraction from shrimp head with autolysis and fermentation using Bacillus licheniformis were investigated. The results showed that when shrimp heads were autolyzed with a natural pH at 50℃ for 4 h, the total amino acid nitrogen in the supernatant was 5.01 mg mL^-1. Then, when a 50%(v/m) inoculum of the hydrolysate was incubated at 60℃ for 10 h, a deproteinization rate of 88.3% could be obtained. The fermented supernatant was processed into a dry protein powder, while the residues were demineralized by 10% citric acid for chitin. The recovered protein powder contained 5.5% moisture, 11.5% ash, and 66.7% protein, while the chitin contained 3.5% moisture, 2.1% ash, and 3.1% protein. In addition, amino acids, minerals, heavy metals, the degree of acetylation, microstructure, and Fourier-transform infrared(FT-IR) spectroscopy results were analyzed. Furthermore, the statistics of the large scale trial after treatment with 20 kg of shrimp heads were analyzed. Thus, this work made the shrimp waste utilization environmentally sound and valuable. 展开更多
关键词 SHRIMP head WASTE ENDOGENOUS enzyme AUTOLYSIS FERMENTATION CHITIN
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不同发酵方式制备树莓-石榴复合果汁酵素的抗氧化活性研究 预览
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作者 覃引 熊音如 +2 位作者 卢丽 边疆 张群英 《中国酿造》 CAS 北大核心 2019年第10期105-109,共5页
以树莓、石榴复合果汁为原料,采用自然发酵、单一添加嗜热链球菌(Streptococcus thermophilus)、单一添加干酪乳杆菌(Lactobacillus casei)及同时添加嗜热链球菌和干酪乳杆菌发酵四种方式制备酵素,并对其发酵过程中的p H值、总酚、总黄... 以树莓、石榴复合果汁为原料,采用自然发酵、单一添加嗜热链球菌(Streptococcus thermophilus)、单一添加干酪乳杆菌(Lactobacillus casei)及同时添加嗜热链球菌和干酪乳杆菌发酵四种方式制备酵素,并对其发酵过程中的p H值、总酚、总黄酮及抗氧化能力(·OH、O2^-·及DPPH自由基清除率)变化进行研究,以评价不同制备方式对树莓-石榴复合果汁酵素抗氧化活性的影响。结果表明,混菌发酵方式优于单菌发酵和自然发酵方式,能增加树莓-石榴复合果汁酵素中总酚含量、总黄酮含量,并提高其抗氧化能力。混菌发酵72 h时,总酚含量(0.57 mg/m L)、·OH清除率(67%)及O2^-·清除率(54%)最高;发酵60 h时,总黄酮含量(0.41 mg/g)及DPPH自由基清除率(94%)最高;p H值变化最小,利于发酵进行。 展开更多
关键词 酵素 树莓 石榴 抗氧化活性 发酵方式
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酿造酒中非酿酒酵母的研究进展 预览
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作者 卜光明 周化斌 +1 位作者 周茂洪 杨海龙 《食品工业科技》 CAS 北大核心 2019年第14期346-352,共7页
非酿酒酵母种类丰富,主要包括假丝酵母、有孢汉生酵母、汉生酵母、伊萨酵母、克鲁维酵母、梅氏酵母、迈耶氏酵母、毕赤酵母、红酵母、复膜孢酵母、裂殖酵母、有孢园酵母、威克氏酵母等,广泛存在于酿造原料、发酵剂及酿酒环境中,其代谢... 非酿酒酵母种类丰富,主要包括假丝酵母、有孢汉生酵母、汉生酵母、伊萨酵母、克鲁维酵母、梅氏酵母、迈耶氏酵母、毕赤酵母、红酵母、复膜孢酵母、裂殖酵母、有孢园酵母、威克氏酵母等,广泛存在于酿造原料、发酵剂及酿酒环境中,其代谢产物及分泌的酶类对酿造酒的香气、风味具有重要的影响,本文综述了近十几年来酿造酒中非酿酒酵母种类分析及群落多样性的研究方法、生长条件及其在酿造中的作用,分析了目前存在的问题,并展望了非酿酒酵母在酿造酒发酵中的应用,以期对优良非酿酒酵母菌株的筛选、特色酿造酒产品的生产提供参考。 展开更多
关键词 非酿酒酵母 酿造酒 风味成分
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饲料酶制剂的研究进展 预览
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作者 严毅梅 《中国饲料添加剂》 2019年第7期37-40,共4页
在当前的畜牧业发展中,酶也起到了重要的作用,特别是在动物营养方面,饲料中添加酶有诸多作用,可使饲料中营养成分得到更好的吸收,提高饲料利用率;降解饲料中一些不可吸收成分,或者降解一些没有价值甚至有毒成分;改善畜禽胃肠机能,有效... 在当前的畜牧业发展中,酶也起到了重要的作用,特别是在动物营养方面,饲料中添加酶有诸多作用,可使饲料中营养成分得到更好的吸收,提高饲料利用率;降解饲料中一些不可吸收成分,或者降解一些没有价值甚至有毒成分;改善畜禽胃肠机能,有效抑制肠道中病原菌的繁殖,提高机体免疫力,降低发病率和死亡率。 展开更多
关键词 提高免疫力 提高饲料的利用率
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NaCl胁迫对水培‘吉美’海棠生理特性的影响 预览
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作者 孙晓刚 张雪 +1 位作者 刘晓嘉 丁绍文 《经济林研究》 北大核心 2019年第4期27-34,共8页
为了给‘吉美’海棠在城市绿化中的应用提供参考,以‘吉美’海棠扦插苗为试验材料,采用水培试验法,设置NaCl浓度为0(CK)、50、100、150和200 mmol/L的5个处理,研究不同浓度NaCl胁迫条件下‘吉美’海棠植株的生长和生理特性的变化。结果... 为了给‘吉美’海棠在城市绿化中的应用提供参考,以‘吉美’海棠扦插苗为试验材料,采用水培试验法,设置NaCl浓度为0(CK)、50、100、150和200 mmol/L的5个处理,研究不同浓度NaCl胁迫条件下‘吉美’海棠植株的生长和生理特性的变化。结果表明:随着NaCl胁迫时长的延长,在50和100 mmol/L NaCl胁迫条件下,‘吉美’海棠的新梢生长量、叶片水势、叶片相对含水量、叶绿素含量、净光合速率、气孔导度、蒸腾速率、最大光化学效率和实际光能转化率均呈下降趋势,胞间CO2浓度为上升趋势,超氧化物歧化酶(SOD)和过氧化物酶(POD)活性的整体变化趋势均为先上升、后下降;在150 mmol/L NaCl胁迫条件下,胞间CO2浓度为先上升、后下降、最后上升的趋势,SOD和POD活性为下降趋势,其他生长和生理指标变化规律与50和100 mmol/L NaCl胁迫条件下的变化规律相同;在200 mmol/L NaCl胁迫条件下,除了胞间CO2浓度值为先上升、后下降的趋势外,其他生长和生理指标变化规律与150 mmol/L NaCl胁迫条件下的变化规律相同。在低浓度NaCl胁迫(50 mmol/L)条件下,‘吉美’海棠的生长和生理活动未受到明显的影响,说明‘吉美’海棠具有一定的抗NaCl胁迫的能力。随着胁迫时长的延长和胁迫程度的增加,‘吉美’海棠的生长和生理活动受到的影响程度也随之增加。所以,在园林景观应用过程中,对‘吉美’海棠应采取合理的盐分管理措施,避免生长于高浓度NaCl的胁迫环境中。 展开更多
关键词 ‘吉美’海棠 NACL胁迫 叶片水势 光合参数
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有机废弃物好氧堆肥过程中微生物及酶活性变化状况综述
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作者 马闯 扈斌 +3 位作者 刘福勇 张宏忠 魏明宝 赵继红 《环境工程》 CAS CSCD 北大核心 2019年第9期159-164,187共7页
系统总结了有机固体废物好氧堆肥化处理过程的调控手段、堆肥各个阶段的微生物群落演替、堆肥过程中酶活性的变化以及臭气的产生情况。堆肥过程中温度变化对微生物的生长繁殖产生显著影响,微生物群落先由嗜温菌演替至嗜热菌,再由嗜热菌... 系统总结了有机固体废物好氧堆肥化处理过程的调控手段、堆肥各个阶段的微生物群落演替、堆肥过程中酶活性的变化以及臭气的产生情况。堆肥过程中温度变化对微生物的生长繁殖产生显著影响,微生物群落先由嗜温菌演替至嗜热菌,再由嗜热菌演替至嗜温菌,有机物被逐步降解。各种有机物降解需不同酶参与,主要有芳基硫酸酯酶、脲酶、蛋白酶、葡萄糖激酶、纤维素酶、β-葡萄糖苷酶、过氧化物酶等;微生物发酵过程蛋白质的降解产生NH3,厌氧条件下硫酸盐还原菌与产甲烷菌的生命活动产生H2S,氨基酸脱羧作用、厌氧降解及局部厌氧发酵产生挥发性有机物(VOCs),这些臭味物质均会对环境造成二次污染。可以尝试调控微生物酶系统来提高堆肥效率,并阻断发酵过程中臭气物质的产生。 展开更多
关键词 有机废弃物 好氧堆肥 微生物 臭气
淀粉表面施胶剂制备系统常见故障与处理 预览
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作者 吕晓峰 钱雪峰 张小红 《中华纸业》 CAS 2019年第10期61-63,共3页
淀粉是一种重要的造纸表面施胶剂原料。由于原淀粉黏度高,流动性差,易产生凝沉现象,因此需要对淀粉进行改性,使其在较高浓度时仍具有较低的黏度,满足纸页表面施胶处理的要求。在实际生产中,商品淀粉是不溶性的白色粉末,厂家应根据需要... 淀粉是一种重要的造纸表面施胶剂原料。由于原淀粉黏度高,流动性差,易产生凝沉现象,因此需要对淀粉进行改性,使其在较高浓度时仍具有较低的黏度,满足纸页表面施胶处理的要求。在实际生产中,商品淀粉是不溶性的白色粉末,厂家应根据需要完成淀粉悬浮液的“糊化”过程,制备淀粉胶[1]。目前,大型纸机都会配置淀粉连续制备设备,用于制备淀粉胶。连续蒸煮设备自动运行,不需要人为操作,具有质量稳定、产量高等优点[2]。比较常见的制备工艺如图1。 展开更多
关键词 淀粉 淀粉酶 故障 处理
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Benefits of Biochars and NPK Fertilizers for Soil Quality and Growth of Cowpea (Vigna unguiculata L. Walp.) in an Acid Arenosol
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作者 Rogerio Borguete Alves RAFAEL Maria Luisa FERNANDEZ-MARCOS +3 位作者 Stefania COCCO Maria Letizia RUELLO Flavio FORNASIER Giuseppe CORTI 《土壤圈:英文版》 SCIE CAS CSCD 2019年第3期311-333,共23页
Fertilization is required for optimum plant growth, particularly in unfertile soils, while optimizing nutrient use effciency is an alternative to reduce inorganic fertilizer needs and reduce environmental problems cau... Fertilization is required for optimum plant growth, particularly in unfertile soils, while optimizing nutrient use effciency is an alternative to reduce inorganic fertilizer needs and reduce environmental problems caused by nutrient leaching. This study investigated soil properties and cowpea yield responses to biochars(BCs) made from different feedstocks, baby corn peel biochar(BC1), branches of mango tree biochar(BC2), and rice husk biochar(BC3), applied in combination with nitrogen-phosphorus-potassium(NPK) fertilizers.The experiment was conducted in a greenhouse, using an acid sandy soil(Arenosol) that was submitted for 70 d to the following eight treatments: i) control;ii) full dose of NPK(a commercial compound fertilizer(12-24-12 of N-P2O5-K2O)+ urea(46% N));iii) BC1+ half dose of NPK;iv) BC1 + full dose of NPK;v) BC2 + half dose of NPK;vi) BC2 + full dose of NPK;vii) BC3 + half dose of NPK;and viii) BC3 + full dose of NPK. All biochars were applied at a rate of 0.9%(weight/weight), and each type of biochar was combined with half and full doses of NPK fertilizers. Soil pH increased significantly(P < 0.05) in treatments with BC1 and BC2,while cation exchange capacity(CEC) and available P were higher in the treatments with BC1;BC1 and BC2 also induced higher activity of enzymes related to the P cycle and higher cowpea yield. Similar soil properties and cowpea yield parameters were obtained with the full and half doses of NPK fertilizers for each type of biochar used. In conclusion, biochars in the combination with NPK fertilizers improved soil chemistry and enzymatic activities, allowing reduced fertilizer application and food production costs in the acid soil studied. 展开更多
关键词 ACID SOIL NUTRIENT use effciency organic amendment plant GROWTH potential enzyme activity SOIL FERTILITY SOIL pH
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