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Analysis of Calcium Content, Hormones, and Degrading Enzymes in Tomato Pedicel Explants During Calcium-Inhibited Abscission 被引量:2
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作者 XU Tao, LI Tian-lai and QI Ming-fang College of Horticulture, Shenyang Agricultural University, Shenyang 110161, P.R.China 《Agricultural Sciences in China》 CSCD 2009年第5期556-563,共8页
This study was designed to analyze the changes of phytohormone concentrations, calcium fraction, and the activities of degrading enzymes during calcium-inhibited and ethyleneglycol-bis-(β-aminoethyl ether)N, N'-te... This study was designed to analyze the changes of phytohormone concentrations, calcium fraction, and the activities of degrading enzymes during calcium-inhibited and ethyleneglycol-bis-(β-aminoethyl ether)N, N'-tetraacetic acid (EGTA)-induced abscission of tomato pedicel explants. Added calcium caused an increase in the total calcium content within the abscission zone and produced a corresponding reduction (20%) in pedicel explant abscission. As expected, EGTA treatment produced the opposite effect and resulted in a decrease in the total calcium content, while accelerating abscission of pedicel explants. Hormone analysis revealed that indole-3-acetic acid (IAA) concentrations in the abscission zone first decreased and then increased before the occurrence of abscission in all treatments, with the greatest effect produced by addition of EGTA. Similarly, abscisic acid (ABA), and gibberellin (GA1+3) concentrations, and ethylene production were elevated in the abscission zone during the first 16 h before abscission when explants imbibed EGTA. With calcium treatment, the concentrations of ABA, ethylene, and GA1+3 also increased in pedicels throughout the first 16 h following exposure, but the increase was slower and less dramatic than with EGTA. Both cellulase and polygalacturonase were induced in the explants during abscission and the activities were also strengthened by treatment with EGTA. Calciumtreated explants produced lower hydrolysing enzyme activities than controls throughout abscission. Calcium played a role of mediating hormone balance and degrading enzymes activities and affected on abscission. 展开更多
关键词 ABSCISSION CALCIUM PHYTOHORMONE degrading enzymes TOMATO
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Pathogenicity of Cell Wall Degrading Enzymes Produced by Botryodiplodia theobromae Pat. against Mangoes
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作者 Min LI Zhaoyin GAO +5 位作者 Meijiao HU Shuo ZHOU Dongping YANG Bo YANG Jianxue YI Fengzhen YANG 《Agricultural Biotechnology》 CAS 2012年第6期18-21,共4页
[ Objective ] This study aimed to confirm the roles of cell wall degrading enzymes (CWDEs) produced by Botryodiplodia theobromae Pat. in the infec- tion of mango fruits. [ Method] Change of activities of five types ... [ Objective ] This study aimed to confirm the roles of cell wall degrading enzymes (CWDEs) produced by Botryodiplodia theobromae Pat. in the infec- tion of mango fruits. [ Method] Change of activities of five types of CWDEs produced by B. theobromae Pat. were studied under both in vitro culture and inocula- tion conditions, along with the pathogenicity and the ability of producing CWDEs of four post-harvest fangal pathogens(B, theobromae Pat. , Colletotrichum gloeos- porioides Penz. , Phomopsis mangiferae Ahmad and Dothiorella dominicana Pet. et Cif. ) which cause stem-end rot of mangoes. [ Result] B. theobromae Pat. was a- ble to produce polygalacturonase(PG), pectinmethylgalacturonase(PMG), polygalacturonic acid trans-eliminase (PGTE), pectin methyltrans-eliminase (PMTE) and cellulase ( Cx. ) under both in vitro culture and inoculation conditions, of which activities of PG, Cx and PMG were significantly higher in than that in either PGTE or PMTE. Among three primary CWDEs, the peak of activities of PG and Cx appeared earlier and that of PMG occured later. The pathogenicity of B. theo- bromae Pat. was significantly higher than that of any other three pathogens; it is the same with the abilities of producing pectinase. [ Conclusion] This paper pro- vides theoretical bases for further exploring the mechanism of host-pathogen interaction and decreasing the post-harvest loss of mango fruits. 展开更多
关键词 Botryodiplodia theobromae Pat cell wall degrading enzymes(CWDEs) PATHOGENICITY
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Identification and Expression of Some Plant Cell Wall-Degrading Enzymes Present in Three Ontogenetics Stages of Thecaphora frezii, a Peanut (<i>Arachis hypogaea</i>L.) Pathogenic Fungus
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作者 Néstor Walter Soria Ana Cristina Figueroa +3 位作者 María Soledad Díaz Valeria Roxana Alasino Pablo Yang Dante Miguel Beltramo 《American Journal of Plant Sciences》 2022年第1期1-22,共22页
Peanuts can be affected by the presence of pathogenic microorganisms. The fungus <i>Thecaphora frezii</i> (<i>T. frezii</i>), which belongs to the taxonomic class Ustilaginomycetes, is the caus... Peanuts can be affected by the presence of pathogenic microorganisms. The fungus <i>Thecaphora frezii</i> (<i>T. frezii</i>), which belongs to the taxonomic class Ustilaginomycetes, is the causal agent of the disease known as “peanut smut”. The life cycle of this fungus includes three stages, namely teliospores, basidiospores and hyphae. In the hyphae stage, infection occurs in the peanut plant, which requires the involvement of some enzymes secreted by the fungus. These include the Plant Cell Wall-Degrading Enzymes (PCWDEs), which degrade various polysaccharides. This study aimed to identify the presence of transcript for enzymes belonging to the PCWDEs from three stages of <i>T. frezii</i>. For this, total RNA was extracted from the three ontogenetic stages of <i>T. frezii</i>. These samples were analyzed using an RNA-Seq approach and some transcripts were quantified using Real Time PCR. The analysis of the data provided by the RNA-Seq of the three <i>T. frezii</i> stages, it was possible to identify some transcripts that could encode enzymes compatible with polysaccharides degradation that are part of the plant cell wall. In <i>T. frezii</i> transcriptome, 40 deduced proteins would be enzymes with functions of PCWDEs were identified. They were divided into 27 glycoside hydrolases;two polysaccharide lyases;three carbohydrate esterases and eight enzymes with auxiliary activities. In addition, the fungal SNF1 gene was identified whose activity could be affected by high glucose level, and indirectly influence the levels of some PCWDEs. The analysis of the PCWDEs could help to understand part of the fungal infection process and possibly find substances that can control its development. 展开更多
关键词 Carbohydrate-degrading enzymes Phytopathogenic Fungi Smut Fungi TRANSCRIPTOME Thecaphora frezii
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Reduction in Activity/Gene Expression of Anthocyanin Degradation Enzymes in Lychee Pericarp is Responsible for the Color Protection of the Fruit by Heat and Acid Treatment 被引量:7
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作者 FANG Fang ZHANG Zhao-qi +3 位作者 ZHANG Xue-lian WU Zhen-xian YIN Hui-fang PANG Xue-qun 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2013年第9期1694-1702,共9页
Heat and acid treatments were reported to be a promising substitute for SO2 fumigation in color protection of postharvest lychee (Litchi chinensis) fruits, but the mechanism was not clear. In the present study, hot ... Heat and acid treatments were reported to be a promising substitute for SO2 fumigation in color protection of postharvest lychee (Litchi chinensis) fruits, but the mechanism was not clear. In the present study, hot water (70℃) dipping followed by immersion in 2% HC1 (heat-acid) substantially protected the red color of the fruit during storage at 25℃ and inhibited anthocyanin degradation while hot water dipping alone (heat) led to rapidly browning and about 90% loss in anthocyanin content. The pH values in the pericarp of the heat-acid treated fruit dropped to 3.2, while the values maintained around 5.0 in the heat-treated and control fruit. No significantly different pH values were detected among the arils of heat-acid, heat treated and control fruit. Heat-acid treatment dramatically reduced the activities of anthocyanin degradation enzyme (ADE), peroxidase (POD) and polyphenol oxidase in the pericarp. A marked reduction in LcPOD gene expression was also detected in heat-acid treated fruit, in contrast, induction was found in heat treated fruit. The pericarp of heat-acid treated fruit exhibited significantly lower respiration rate but faster water loss than that of the untreated or heat treated fruit. Taken together, heat treatment triggered quick browning and anthocyanin loss in lychee fruit, while heat-acid treatment protected the fruit color by a great reduction in the activities/gene expression of anthocyanin degradation enzymes and acidification of lychee pericarp. 展开更多
关键词 lychee fruit anthocyanin degradation enzymes color retention heat and acid treatment peroxidase geneexpression
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Optimization and Characterization of Nicosulfuron-Degrading Enzyme from Bacillus subtilis Strain YB1 被引量:5
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作者 KANG Zhan-hai Dong Jin-gao ZHANG Jin-lin 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2012年第9期1485-1492,共8页
A strain of Bacillus subtilis strain YB 1, isolated and preserved in our lab., showed a high nicosulfuron-degrading activity. Optimization of culture conditions on production of nicosulfuron-degrading enzyme from Baci... A strain of Bacillus subtilis strain YB 1, isolated and preserved in our lab., showed a high nicosulfuron-degrading activity. Optimization of culture conditions on production of nicosulfuron-degrading enzyme from Bacillus subtilis strain YB 1 was carried out through mono-factor experiments. The characterization of degrading enzyme(s) was studied in this paper. The results showed that B. subtilis YB1 can use nicosulfuron as sole carbon source under aerobic condition. The key enzyme(s) involved in the initial biodegradation of nicosulfuron was localized to extracellular proteins and showed to be induced expressed. Enzyme-specific activity was up to 89.34 U mg-1 at pH 8.0 and 30℃, incubation for 96 h, inoculum 4.5x108 CFU mL-1 in Luria-Bertani liquid medium with nicosulfuron of 40 mg L-1. The maximum degradation rate of extracellular crude enzymes on nicosulfuron was 66% at pH 9.0, 35℃ in the enzymatic reaction system with nicosulfuron of 5 mg L-1. This degrading enzyme(s) was sensitive to high temperature, but kept high activity under alkaline conditions. 展开更多
关键词 Bacillus subtilis NICOSULFURON microbial degradation enzymE
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Isolation,Identification and Characteristics of Cellulose-degrading Bacteria
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作者 Shasha LIU Ruiji LU Nuo CHEN 《Asian Agricultural Research》 2023年第12期43-45,共3页
[Objectives]To isolate and identify characteristics of the cellulose-degrading bacteria.[Methods]In view of the poor effect of crop straw composting,the strains which can degrade cellulose were isolated and purified f... [Objectives]To isolate and identify characteristics of the cellulose-degrading bacteria.[Methods]In view of the poor effect of crop straw composting,the strains which can degrade cellulose were isolated and purified from the soil piled with rice straw,and the strains A2 and A5 with high efficiency of cellulose degradation were finally screened through the transparent circle,cellulase activity and filter paper disintegration experiments.[Results]It was confirmed that the strains A2 and A5 could degrade cellulose well.The results of 16s rDNA showed that A2 was Pseudoxanthomonas mexicana and A5 was Bacillus cibi.[Conclusions]The results of this study are expected to provide high-quality strain resources for the degradation of cellulose in straw,and have important application value for improving the efficiency of straw composting. 展开更多
关键词 CELLULOSE degrading BACTERIA enzymE ACTIVITY degradATION effect
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Neuroprotective mechanism of Kai Xin San: upregulation of hippocampal insulin-degrading enzyme protein expression and acceleration of amyloid-beta degradation 被引量:11
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作者 Na Wang Yong-ming Jia +5 位作者 Bo Zhang Di Xue Maharjan Reeju Yan Li Shu-ming Huang Xue-wei Liu 《Neural Regeneration Research》 SCIE CAS CSCD 2017年第4期654-659,共6页
Kai Xin San is a Chinese herbal formula composed of Radix Ginseng, Poria, Radix Polygalae and Acorus Tatarinowii Rhizome. It has been used in China for many years for treating amnesia. Kai Xin San ameliorates amyloid-... Kai Xin San is a Chinese herbal formula composed of Radix Ginseng, Poria, Radix Polygalae and Acorus Tatarinowii Rhizome. It has been used in China for many years for treating amnesia. Kai Xin San ameliorates amyloid-β (Aβ) induced cognitive dysfunction and is neuroprotective in vivo, but its precise mechanism remains unclear. Expression of insulin-degrading enzyme (IDE), which degrades Aβ, is strongly correlated with cognitive function. Here, we injected rats with exogenous Aβ42 (200 μM, 5 μL) into the hippocampus and subsequently administered Kai Xin San (0.54 or 1.08 g/kg/d) intragastrically for 21 consecutive days. Hematoxylin eosin and Nissl staining revealed that Kai Xin San protected neurons against Aβ-induced damage. Furthermore, enzyme linked immunosorbent assay, western blot and polymerase chain reaction results showed that Kai Xin San decreased Aβ42 protein levels and increased expression of IDE protein, but not mRNA, in the hippocampus. Our findings reveal that Kai Xin San facilitates hippocampal Aβ degradation and increases IDE expression, which leads, at least in part, to the alleviation of hippocampal neuron injury in rats. 展开更多
关键词 nerve regeneration NEURODEGENERATION traditional Chinese medicine Kai Xin San insulin-degrading enzyme amyloid-β Alzheimer'sdisease Chinese herbal compound Aβ-degrading enzymes neurons Radix Ginseng Radix Polygalae Acorus Tatarinowii Rhizoma neuralregeneration
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Degradation Behaviors of Thai <i>Bombyx mori</i>Silk Fibroins Exposure to Protease Enzymes 被引量:1
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作者 Chuleerat Wongnarat Prasong Srihanam 《Engineering(科研)》 2013年第1期61-66,共6页
The degradation behaviors of Thai Bombyx mori called Samrong and Nanglai silk fibroins exposure to protease enzymes;protease XIV, protease XXIII and α-chymotrypsin type II were studied in this work. The degradation b... The degradation behaviors of Thai Bombyx mori called Samrong and Nanglai silk fibroins exposure to protease enzymes;protease XIV, protease XXIII and α-chymotrypsin type II were studied in this work. The degradation behaviors were expressed by their weight loss, morphological and secondary structure changes as well as thermal properties. Samrong showed higher percentage of weight loss than Nanglai. SEM micrographs indicated that silk fibroin were de- stroyed and showed many holes on their fiber surfaces. All of silk samples were increasable destroyed when exposure to the protease enzyme for long incubation period. With thermal analysis, both silk fibroin presented the thermal stability in the same profile. The result suggested that the selected silk fibroin should be composed of similar pattern of amino acids and their ratios. However, the protease susceptibility of each silk fibroin slightly varied in case of morphology observation. This might be affected by their genetic variety. 展开更多
关键词 degradation enzyme PROTEASE Samrong Nanglai
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Purification and Characterization of a Nonylphenol (NP)-degrading Enzyme from Bacillus cereus.Frankland
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作者 YANG Ge ZHANG Ying BAI Yanfen 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2011年第4期644-648,共5页
<Abstract>An extracellular NP-degrading enzyme secreted by Bacillus cereus.Frankland was purified to homogeneity by a combination of ammonium sulfate precipitation,Phenyl-Sepharose hydrophobic-interaction chroma... <Abstract>An extracellular NP-degrading enzyme secreted by Bacillus cereus.Frankland was purified to homogeneity by a combination of ammonium sulfate precipitation,Phenyl-Sepharose hydrophobic-interaction chromatography and DEAE anion-exchange chromatography.On SDS(sodium dodecyl sulfate)-polyacrylamide gel electrophoresis analysis,the purified enzyme showed a relative molecular mass of 58.3 kDa.The depolymerzation of subunits was accompanied with the loss of NP-degrading enzyme activity,and removing denaturing factors by dialysis could restore the dimer structure and enzymatic activity.The enzyme had an isoelectric point of 5.5 and an optimal temperature of 60℃,and was the most active at pH 6.0.The enzymatic activity was stable at pH 4-8 and inhibited by Cu2+.TenN-terminal amino acids were determined to be ASVNSIKIGY,demonstrating that the purified enzyme was a novel one.The hydrolysis pattern of the purified enzyme indicated that the NP-degrading enzyme was an endo NP-degrading enzyme.The extraordinary thermo-stability provided the enzyme with a good prospect to be used as a new tool for clean-production process for textile industry. 展开更多
关键词 层析纯化 降解酶 NP 芽孢杆菌 壬基酚 十二烷基硫酸钠 表征 蜡样芽胞杆菌
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Cell wall degrading isoenzyme profiles of Trichoderma biocontrol strains show correlation with rDNA species
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作者 Sanz L Hermosa M R +1 位作者 González F J Monte E 《浙江大学学报(农业与生命科学版)》 CAS CSCD 北大核心 2004年第4期457-457,共1页
Species of the fungus Trichoderma, a genus of Hyphomycetes, are ubiquitous in the environment, but especially in soil. They have been used in a wide range of commercial applications including the production of hydrola... Species of the fungus Trichoderma, a genus of Hyphomycetes, are ubiquitous in the environment, but especially in soil. They have been used in a wide range of commercial applications including the production of hydrolases and in the biological control of plant diseases. A fundamental part of the Trichoderma antifungal system consists of a series of genes coding for a surprising variety of extracellular cell wall degrading enzymes (CWDE). Characterisation and identification of strains at the species level is the first step in utilizing the full potential of fungi in specific applications. One aim when isolating Trichoderma strains is to identify those which can be used in new agricultural and industrial applications. In the past it was not uncommon that biocontrol strains were defined as T. harzianum Rifai, due to the limited classification system of the genus Trichoderma. In recent years, several PCR-based molecular techniques have been used to detect and discriminate among microorganisms. Sequence analysis of the ITS regions of the ribosomal DNA and gene fragments as those corresponding to tef1 gene have been helpful in the neotypification, description and characterization of species in the genus Trichoderma. Another useful method for the identification of Trichoderma strains is the randomly amplified polymorphic DNA (RAPD) technique. Isozyme polymorphisms evaluation of five putative extracellular lytic enzymes loci (β-1,3-glucanase, β-1,6-glucanase, cellulase, chitinase and protease antivities) were carried out using representative strains of defined molecular groups. CWDE groupings obtained from biocontrol strains are discussed in relation to their phylogenetic location and antifungal activities. Compiling morphological, biochemical and sequence information data into a common database would provide a useful resource that could be used to accurately name new haplotypes identified in the future and correctly place them within the genus Trichoderma. 展开更多
关键词 细胞壁降解同功酶 生物防治 菌株 木霉属 真菌 RDNA
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Cloning and Characterization of a Galactomannan-degrading Enzyme Gene in Pichia pastoris
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作者 Yuyong WU Jiao LIU +2 位作者 Guangyun LU Jiahui LIU Xiaoli LIU 《Agricultural Biotechnology》 CAS 2015年第5期69-72,76,共5页
[ Objective ] This study aimed to obtain the recombinant Pichia yeast strain which can efficiently degrade guar gum. The properties of the recombinant enzyme were studied preliminarily. [ Method ] A positive clone tha... [ Objective ] This study aimed to obtain the recombinant Pichia yeast strain which can efficiently degrade guar gum. The properties of the recombinant enzyme were studied preliminarily. [ Method ] A positive clone that could hydrolyze guar gum was obtained through the construction and functional screening of a soil genome library. Sequence analysis indicated that the 1485-bp clone encodes a 494-amino acid protein with a relative molecular mass of 53 949 kD, containing a cellulose-binding domain. The recombinant plasmid pHBM731 was generated by inserting the optimized target gene into a Pichia pastoris expression vector pHBMg05 that was transformed into three Pichia pastoris strains, GS115, KM71 and SMD1168. The biochemical properties of the enzyme were assessed. [ Result] The cloned galactonumnan (GM)-degrading enzyme was expressed and secreted by Pichia pastoris GSll5. High cell density fermentation was induced in recombi- nant Pichia pastoris at 25 and 28 ~C ; a higher enzyme activity was observed at an induction temperature of 28 ~C. The optimal temperature for the recombinant en- zyme is 60 ~C, and the optimal pH is 6.6. The enzyme activity was 38.61 U under optimal conditions. Over 50% of the enzyme activity was maintained under the optimal conditions after 9 h. Under the optimal conditions, the effect of metal ions on enzyme activity was analyzed. Ca2 + , Fe2 + and Li ~ slightly enhanced enzyme activity, while Mn2+ and Co2+ had little effect. Enzyme activity was modestly suppressed by Mg2~ , K~ and Na+ , but considerably suppressed by Ag2~ and Zn2~ , with Cu2 + showing the strongest inhibitory effects. [ Conclusion] A novel GM-degrading enzyme expressed by soil yeast was cloned, which can potentially be used in industrial applications to obtain eommereially useful guar gum-degradation products. 展开更多
关键词 Galactomarman-degrading enzyme Pichia pastoris Gene cloning Secreted expression enzyme activity enzymatie properties
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Insights into seasonal variation of litter decomposition and related soil degradative enzyme activities in subtropical forest in China 被引量:6
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作者 WANG Cong-yan Lü Yan-na +2 位作者 WANG Lei LIU Xue-yan TIAN Xingjun 《Journal of Forestry Research》 SCIE CAS CSCD 2013年第4期683-689,共7页
We used a litterbag method to investigate litter decomposition and related soil degradative enzyme activities across four seasons in a broad-leaved forest and a coniferous forest on Zijin Mountain in sub-tropical Chin... We used a litterbag method to investigate litter decomposition and related soil degradative enzyme activities across four seasons in a broad-leaved forest and a coniferous forest on Zijin Mountain in sub-tropical China. Across four seasons, we quantified litter mass losses, soil pH values, and related soil degradative enzyme activities. Litter decomposition rates differed significantly by season. Litter decomposi- tion rates of broadleaf forest leaves were higher than for coniferous for- ests needles across four seasons, and maximal differences in litter de- composition rates between the two litter types were found in spring. 展开更多
关键词 broad-leaved forest coniferous forest litter decomposition soil degradative enzyme
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The Mechanism of Carotenoid Degradation in Flue-Cured Tobacco and Changes in the Related Enzyme Activities at the Leaf-Drying Stage During the Bulk Curing Process 被引量:6
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作者 SONG Zhao-peng LI Tong-shuai +3 位作者 ZHANG Yong-gang CAO Hui-jing GONG Chang-rong ZHANG Wei-jian 《Agricultural Sciences in China》 CSCD 2010年第9期1381-1388,共8页
The mechanism of carotenoid degradation and the changes in the activities of related enzymes in flue-cured tobacco at the leaf-drying stage during the bulk-curing process were studied in order to provide theoretical b... The mechanism of carotenoid degradation and the changes in the activities of related enzymes in flue-cured tobacco at the leaf-drying stage during the bulk-curing process were studied in order to provide theoretical basis for optimization of curing technology. The effect of different rising speeds of temperature on the carotenoid degradation and the related enzymes activities at the color-fixing stage during the bulk curing process was studied by using the electric-heated fluecuring barn designed by Henan Agricultural University, China, based on curing technology with yellowing at low temperature and moderate humidity and leaf drying at moderate humidity. The results showed that the carotenoid degradation components (β-carotene, lutein, neoxanthin, and violaxthin) decreased gradually at the color-fixing stage during the bulk curing process. The carotenoid degradation components viz.,β-carotene, lutein, neoxanthin, and violaxthin at the slow heating curing (T1) were relatively higher than the rapid heating curing (T2) accounting for 10, 2, 32 and 32% respectively, but there were no differences among treatments (P〉 0.05). The effect of different conditions of curing on the activities of enzymes related to carotenoids degradation were significant. The lipoxygenase, phenylalanine ammonialyase, peroxidase, and polyphenol oxidase enzymes had a bidirectional effect on the quality of tobacco leaves and it was beneficial to form more premise matter of aroma based on the higher enzyme activities at the early leaf-drying stage. The slow heating could regulate the change in various enzymes' activities reasonably, making cell redox reaction to reach the dynamic balance and make the degradation of carotenoids adequately. Meanwhile, it could avoid the occurrence of browning reaction and provide foundation for improving the quality of tobacco and optimization of technology for bulk curing and further enhancing aroma. 展开更多
关键词 bulk curing leaf-drying stage carotenoids mechanism of degradation enzyme
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No Statistic Correlation between Superoxide Dismutase and Peroxidase Activities and Aluminum-Induced Lipid Peroxidation in Maize, Implying Limited Roles of Both Enzymes in Prevention against Aluminum-Induced Lipid Peroxidation
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作者 Liang Wang Jian-Yu Zhao +5 位作者 San-Min Wu Jiang-long Pan Zhang-Bao Huang Zi-Kai Wu Xian-Wei Fan You-Zhi Li 《American Journal of Plant Sciences》 2011年第2期156-164,共9页
Changes of and correlation among root tolerance index (RTI), root Aluminum (Al) content, root/shoot ratio (RSR), root malondialdehyde (MDA) content, and Superoxide dismutase (SOD) and peroxidase (POD) isoforms of maiz... Changes of and correlation among root tolerance index (RTI), root Aluminum (Al) content, root/shoot ratio (RSR), root malondialdehyde (MDA) content, and Superoxide dismutase (SOD) and peroxidase (POD) isoforms of maize YQ 7-96 were investigated under Al stress and removal of the stress (RS). Consequently, Al stress led to significant decreases in RTI, RSR, SOD and POD activities, but resulted in significant increase in root MD A and, Al accumulation in the tissues;Root SOD and POD activities did not correlate with Al and MDA contents in roots;The activities of SOD and POD were much lower in roots than in leaves. It can be concluded that (1) Al stress can lead to lipid peroxidation;(2) there is a larger POD family composed of different POD isoforms, some of which are of tissue-specific expression and play different roles in detoxification of Al in maize;(3) for POD isoforms, POD 2 is root-specific. POD 6 and POD 7 are all leaf-specific, POD 5 is not only root-specific but also RS-responsive;(4) high sensitivity of maize to Al is in part associated with much lower activities of both SOD and POD in roots;and (5) more importantly, both SOD and POD are therefore hinted to be not key players in prevention against Al-induced lipid peroxidation. 展开更多
关键词 Al Toxicity Antioxidant enzyme ANTIOXIDATION Lipid degradation Plant
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Interactions between Two Fungi Strains during Litter Decomposition through a Microcosm Experiment: Different Degradative Enzyme Activities
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作者 Yan Chen Gaozhong Pu +4 位作者 Bo Lian Xiuxia Pei Guifang Huang Qifeng Wang Yanna Lv 《Advances in Enzyme Research》 2018年第1期1-9,共9页
Fungi are the key agents in litter decomposition in forest ecosystems. However, the specific roles of the interactions between different fungal species during litter decomposition process are unclear. To evaluate the ... Fungi are the key agents in litter decomposition in forest ecosystems. However, the specific roles of the interactions between different fungal species during litter decomposition process are unclear. To evaluate the interactions, two fungi strains with significantly different morphs were isolated from the soils of Quercus acutissima forest and Pinus massoniana forest, and inoculated in the litter powder of Quercus acutissima leaves and Pinus massoniana needles with grown separately and in coexistence equally through a microcosm experiment. The enzyme activities were determined as a proxy for microbial activities. The results showed that the degradative enzymes involved in litter decomposition showed varying dynamics pattern during the incubation period. The interactions between the two fungi strains are synergism, and benefit to each other according to enzyme activities, suggesting that a fungi strain growth was accelerated by the presence of other fungi strain during litter decomposition process. However, the interactions of the two fungi strains were bilateral antagonism inoculated in the litter powder of Quercus acutissima leaves according to cellobiohydrolase activities. The synergism, despite bilateral antagonism in an exceptional case, may be an important factor controlling the fungal colonization and growth on litter substrate. The results implied that more fungal species may accelerate litter decomposition rates due to their mutual cooperation. 展开更多
关键词 ANTAGONISM degradative enzymes FUNGI INTERACTIONS LITTER Decomposition Synergism
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Novel method for separation and screening of lubricant-degrading microorganisms and bacterial biodegradation
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作者 Yan Jiang Hui Qi Xianming Zhang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2016年第3期353-359,共7页
With the rapid increase of lubricant consumption,oil contamination becomes more serious.Biotreatment is an important method to remove oil contamination with some advantages.In this study,acclimatized oilcontaminated s... With the rapid increase of lubricant consumption,oil contamination becomes more serious.Biotreatment is an important method to remove oil contamination with some advantages.In this study,acclimatized oilcontaminated soil and used lubricating oil were sampled to isolate lubricant-degrading strains by several methods.51 isolates were obtained and 24-well plates were employed to assess bacterial potential in highthroughput screening.The method was noted for the prominence of oil–water two-phase system with saving chemicals,shortening cycles and lessening workloads.In order to decrease inaccuracy,subculture and resting cells were inoculated into mineral salt medium with 200 μl oil in well plates for the cultivation at 37 °C for 5and 7 days,and the biodegradation potential was characterized by the changes of oil film and cell density.With appropriate evaluation by shaking flask tests,5 isolates were retained for their potentials with the maximum biodegradation from 1500 to 2200 mg · L^(-1)and identified as Acidovorax citrulli,Pseudomonas balearica,Acinetobacter johnsonii(two isolates with different biodegradation potentials)and Acidovorax avenae using 16 S r RNA sequencing analysis.Also,lipase activity was determined using indicator titration and p-nitrophenyl palmitate(p-NPP)methods.The results indicated that only p-NPP was successful to test lipase activity with the range of 1.93–6.29 U · ml^(-1).Although these five strains could degrade 1000 mg · L^(-1)lubricating oil in158–168 h,there existed distinct difference in enzyme activity,which demonstrates that lipase activity could not be used as the criterion to evaluate microbial biodegradation potential for petroleum hydrocarbons. 展开更多
关键词 微生物降解 分离筛选 润滑油 降解微生物 细菌 脂肪酶活性 AVENAE 基因序列分析
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a-Synuclein: A fusion chaperone significantly boosting the enzymaticperformance of PET hydrolase
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作者 Renwen Tian Yan Sun 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2023年第12期18-25,共8页
Extensive use of polyethylene terephthalate (PET) has brought about global environmental problems. Arecently reported PET hydrolase (PETase) discovered from Ideonella sakaiensis showed high potentialfor degrading PET ... Extensive use of polyethylene terephthalate (PET) has brought about global environmental problems. Arecently reported PET hydrolase (PETase) discovered from Ideonella sakaiensis showed high potentialfor degrading PET at moderate temperatures, but its activity and stability need further improvementfor practical applications. Herein, we proposed to use a-synuclein (aS) as a fusion chaperone and createdsix PETase-aS fusion enzymes with linkers of different types and lengths. All the fusion enzymes exhibited improved enzymatic performance, presenting 1.5 to 2.6-fold higher activity towards bis-2(hydroxyethyl) terephthalate than PETase, as well as significantly increased stabilities. Fluorescencespectroscopy indicated that the chaperone fusion tightened the overall conformation and resulted inthe opening of the substrate binding pocket, which led to the improved thermal stability and catalyticactivity of the fusion enzymes. Remarkably, one of the fusion proteins, PETase-[(GS)(EK)]10-aS, showed3.2 to 5.1 times higher PET degradation capability than PETase. The significantly boosted PET degradationperformance was not only attributed to the enhanced enzymatic activity and stability, but also possiblydue to the binding affinity of the fused aS domain for PET. These findings demonstrated that aS was aneffective fusion chaperone for significantly enhancing the enzymatic performance of PETase. 展开更多
关键词 PET hydrolase a-Synuclein Fusion enzyme Stability Pollution degradation
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Safety evaluation and whole genome sequencing for revealing the ability of Penicillium oxalicum WX-209 to safely and effectively degrade citrus segments
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作者 Xiao Hu Yujiao Qian +4 位作者 Zhipeng Gao Gaoyang Li Fuhua Fu Jiajing Guo Yang Shan 《Food Science and Human Wellness》 SCIE CSCD 2023年第6期2369-2380,共12页
The microbial potential of Penicillium has received critical attention.The present research aimed to elucidate the efficacy of crude enzyme secreted from Penicillium oxalicum WX-209 in degrading citrus segments and ev... The microbial potential of Penicillium has received critical attention.The present research aimed to elucidate the efficacy of crude enzyme secreted from Penicillium oxalicum WX-209 in degrading citrus segments and evaluate the safety of the process.Results showed that citrus segment membranes gradually dissolved after treatment with the crude enzyme solution,indicating good degradation capability.No significant differences in body weight,food ingestion rate,hematology,blood biochemistry,and weight changes of different organs were found between the enzyme intake and control groups.Serial experiments showed that the crude enzyme had high biological safety.Moreover,the whole genome of P.oxalicum WX-209 was sequenced by PacBio and Illumina platforms.Twenty-five scaffolds were assembled to generate 36 Mbp size of genome sequence comprising 11369 predicted genes modeled with a GC content of 48.33%.A total of 592 genes were annotated to encode enzymes related to carbohydrates,and some degradation enzyme genes were identified in strain P.oxalicum WX-209. 展开更多
关键词 Penicillium oxalicum WX-209 Crude enzyme degradATION Safety evaluation Genome sequencing
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Screening Psychrophilic Fungi of Cellulose Degradation and Characteristic of Enzyme Production
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作者 Wang Da-qing Jin Wen-ran +3 位作者 Sun Tai-peng Meng Yu-tian Zhao Wei Wang Hong-yan 《Journal of Northeast Agricultural University(English Edition)》 CAS 2016年第2期20-27,共8页
A fungus(WR-C1) decomposed cellulose was isolated from a hypothermal litter layer using Congo red medium as the preliminary screening culture medium and then using a filter as the secondary screening medium at low t... A fungus(WR-C1) decomposed cellulose was isolated from a hypothermal litter layer using Congo red medium as the preliminary screening culture medium and then using a filter as the secondary screening medium at low temperature. The experiment showed that the weight loss rate of filter paper on the 15 th days could reach 30.69%. A morphologic and ITS gene sequence analysis suggested that CF-C1 was Cladosporium. We mainly studied the effects of culture time, inoculation amount, initial p H and different sources of carbon, nitrogen and inorganic salt on the cellulase production of strain WR-C1. Under optimum cultural condition, the highest value of WR-C1 enzyme production and filter paper enzyme were 3.27 U · m L~(-1) and 0.51 U · m L~(-1). 展开更多
关键词 low temperature cellulose-degrading fungi screening enzyme activity
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大曲复合酶系对小麦协同降解作用研究
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作者 江怡佳 易卓林 +1 位作者 赵海 任志强 《中国酿造》 CAS 北大核心 2024年第3期56-62,共7页
为研究大曲复合酶系对天然底物小麦的降解作用,采用异源表达法和亲和层析法纯化来自浓香型白酒大曲的内切淀粉酶(NFAmy13B、NFAmy13A)、内切葡聚糖酶(NFEg16A)和来自Thermoanaerobacterium bryantii mel9T的木聚糖酶(TbXyn10A)及木糖苷... 为研究大曲复合酶系对天然底物小麦的降解作用,采用异源表达法和亲和层析法纯化来自浓香型白酒大曲的内切淀粉酶(NFAmy13B、NFAmy13A)、内切葡聚糖酶(NFEg16A)和来自Thermoanaerobacterium bryantii mel9T的木聚糖酶(TbXyn10A)及木糖苷酶(TbXyl39A、TbXyl52A)。以小麦粉碎物为底物,研究不同酶及配比对小麦降解的影响,并通过对羟基苯甲酸(p HBAH)法测定还原糖含量评估降解效果。结果表明,NFAmy13B是典型的液化淀粉酶,可高效降解长链淀粉,其4 h降解小麦粉碎物得到的还原糖含量为5.12 mmol/L。NFAmy13A是典型糖化性淀粉酶,可高效将短链淀粉降解为麦芽糖,NFAmy13A和NFEg16A可以提高NFAmy13B的降解效率,复配水解效率为NFAmy13B的2.6倍。木聚糖酶和木糖苷酶与NFAmy13B、NFAmy13A、NFEg16复配可进一步提高小麦降解效率,复配水解效率为NFAmy13B的2.9倍。该研究证实大曲复合酶系对小麦粉碎物存在协同降解作用。 展开更多
关键词 大曲复合酶系 小麦 协同降解
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