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1.
Macedo LL Amorim TM Uchôa AF Oliveira AS Ribeiro JK de Macedo FP Santos EA de Sales MP 《Journal of agricultural and food chemistry》2008,56(3):802-808
Chitin-binding vicilin from Erythrina velutina seeds was purified by ammonium sulfate followed by affinity chromatography on a chitin column and gel filtration on Superose-6-10-300-GL. The Erythrina velutina vicilin, called EvV, is a tetrameric glycoprotein composed of 1.85% carbohydrates and M r of 216.6 kDa, consisting of two subunits of M r of 54.8 and two subunits of M r of 50.8 kDa. The EvV homogeneity was confirmed in native PAGE where it was observed to be a unique acid-protein band with slow mobility in this gel. Effect of EvV on C. capitata larvae was examined by bioassay and its mechanism of action was determined by immunodetection techniques and fluorescence localization in chitin structures that are present in C. capitata digestory system. EvV when added to diet caused strong effect on mortality (ED50 of 0.14%) and larval mass (WD50 of 0.12%). These deleterious effects were associated to the binding to chitin structures present in peritrophic membrane and to gut epithelial cells, and its low digestibility in C. capitata digestive tract. These results are the first demonstration of a proteinaceous bioinsecticide from plant origin effective against C. capitata larvae. EvV may be part of the pest management programs or an alternative in plant improvement program. 相似文献
2.
《European Journal of Soil Biology》2002,38(1):75-77
Dipteran larvae play an important role in the soil of some deciduous forests. They can consume a considerable part of the annual litter fall and produce a large amount of faecal pellets, which are forming an important part of the fermentation horizon of forest soils. We measured the pH changes and assayed the activities and pH optima of saccharolytic enzymes in the digestive tracts of the larvae of Bibio pomonae and Penthetria holosericea (Bibionidae). The pH of the litter offered as a food was about 5. The gut content became highly alkaline (pH about 10) in the anterior part of the midgut and the pH decreased posteriorly and in the hindgut. Excrements were neutral or had slightly alkaline pH (7.5–8.0) in both species. The alkaline pH optima of amylase (9.5–10.0) and maltase (8.0), trehalase and cellobiase (7.0) were the same in both species. Saccharolytic activity showed an optimum at pH 7 in B. pomonae and at pH 8 in P. holosericea. Though there are previously published reports of high assimilation efficiency of bibionid larvae fed in litter (46–76% in B. pomonae), activities of both exo and endocellulases were below the detection limit of saccharolytic and chromolytic assays along a wide pH range (5–10). Possible explanations are discussed. 相似文献
3.
《European Journal of Soil Biology》2002,38(1):47-51
To describe the compartmentalization of the gut and the microbial activity in the digestive tract, the histology of the gut wall, enzymatic activity, pH of the gut content, abundance and composition of the microbial community (direct counts, plate counts on various media, and phospholipid fatty acid analyses—PLFA) were studied in the Penthetria holosericea larvae. The highest secretion activity was observed in the caeca and in the part of the anterior midgut before caeca openings. A strong increase in pH (10.5) was observed in the anterior part of the midgut. Some enzymes produced in the caeca might have their maximum activity in a different part of the gut as a result of their pH optimum; e.g. amylase was most active in the strongly alkaline anterior part of the mesenteron. Maltase, hydrolyzing products of starch degradation, was most active in the posterior part of the gut and in the ectoperithrophic space. The microbial community was reduced in the anterior part of the midgut. In the posterior part of the gut, bacterial numbers increased and peaked in excrements. Caeca had an abundant microbial community. 相似文献
4.
Macedo ML de Sá CM Freire MD Parra JR 《Journal of agricultural and food chemistry》2004,52(9):2533-2540
The cowpea weevil Callosobruchus maculatus is one of the major pests of Vigna unguiculata cowpea. Digestion in the cowpea weevil is facilitated by high levels of cysteine and aspartic acid proteinases. Plants synthesize a variety of molecules, including proteinaceous proteinase inhibitors, to defend themselves against attack by insects. In this work, a trypsin inhibitor (ApTI) isolated from Adenanthera pavonina seeds showed activity against papain. The inhibition of papain by ApTI was of the noncompetitive type, with a K(i) of 1 microM. ApTI was highly effective against digestive proteinases from C. maculatus, Acanthoscelides obtectus (bean weevil), and Zabrotes subfasciatus (Mexican bean weevil) and was moderately active against midgut proteinases from the boll weevil Anthonomus grandis and the mealworm Tenebrio molitor. In C. maculates fed an artificial diet containing 0.25% and 0.5% ApTI (w/w), the latter concentration caused 50% mortality and reduced larval weight gain by approximately 40%. The action of ApTI on C. maculatus larvae may involve the inhibition of ApTI-sensitive cysteine proteinases and binding to chitin components of the peritrophic membrane (or equivalent structures) in the weevil midgut. 相似文献
5.
Moura FT Oliveira AS Macedo LL Vianna AL Andrade LB Martins-Miranda AS Oliveira JT Santos EA de Sales MP 《Journal of agricultural and food chemistry》2007,55(2):260-266
Chitin-binding vicilin from Enterolobium contortisiliquum seeds was purified by ammonium sulfate followed by gel filtration on Sephacryl 300-SH and on Sephacryl 200-SH. The vicilin, called EcV, is a dimeric glycoprotein composed of 1.03% carbohydrates and a Mr of 151 kDa, consisting of two subunits of Mr of 66.2 and 63.8 kDa. The EcV homogeneity was confirmed in a PAGE where it was observed to be a unique acid protein band with slow mobility in this native gel. E. contortisiliquum vicilin (EcV) was tested for anti-insect activity against C. maculatus and Zabrotes subfasciatus larvae and for phytopathogenic fungi, F. solani and C. lindemuntianum. EcV was very effective against both bruchids, producing 50% mortality for Z. subfasciatus at an LD50 of 0.43% and affected 50% of the larvae mass with an ED50 of 0.65%. In artificial diets given to C. maculatus, 50% of the larvae mass was affected with an ED50 of 1.03%, and larva mortality was 50% at LD50 of 1.11%. EcV was not digested by midgut homogenates of C. maculatus and Z. Subfasciatus until 12 h of incubation, and at 24 h EcV was more resistant to Z. subfasciatus larval proteases. The binding to chitin present in larvae gut associated to low EcV digestibility could explain its lethal effects. EcV also exerted an inhibitory effect on the germination of F. solani at concentrations of 10 and 20 microg mL-1. The effect of EcV on fungi is possibly due to binding to chitin-containing structures of the fungal cell wall. 相似文献
6.
Araújo CL Bezerra IW Oliveira AS Moura FT Macedo LL Gomes CE Barbosa AE Macedo FP Souza TM Franco OL Bloch-J C Sales MP 《Journal of agricultural and food chemistry》2005,53(11):4381-4387
A proteinaceous inhibitor with high activity against trypsin-like serine proteinases was purified from seeds of the tamarind tree (Tamarindus indica) by gel filtration on Shephacryl S-200 followed by a reverse-phase HPLC Vidac C18 TP. The inhibitor, called the tamarind trypsin inhibitor (TTI), showed a Mr of 21.42 kDa by mass spectrometry analysis. TTI was a noncompetitive inhibitor with a Ki value of 1.7 x 10(-9) M. In vitro bioinsecticidal activity against insect digestive enzymes from different orders showed that TTI had remarkable activity against enzymes from coleopteran, Anthonomus grandis (29.6%), Zabrotes subfasciatus (51.6%), Callosobruchus maculatus (86.7%), Rhyzopertha dominica(88.2%), and lepidopteron, Plodia interpuncptella (26.7%), Alabama argillacea (53.8%), and Spodoptera frugiperda (75.5%). Also, digestive enzymes from Diptera, Ceratitis capitata (fruit fly), were inhibited (52.9%). In vivo bioinsecticidal assays toward C. capitata and C. maculatus larvae were developed. The concentration of TTI (w/w) in the artificial seed necessary to cause 50% mortality (LD50) of larvae was 3.6%, and that to reduce mass larvae by 50.0% (ED50) was 3.2%. Furthermore, the mass C. capitata larvae were affected at 53.2% and produced approximately 34% mortality at a level of 4.0% (w/w) of TTI incorporated in artificial diets. 相似文献
7.
采用PCR方法扩增出苜蓿银纹夜蛾(Autographa californica)核型多角体病毒(AcMNPV)几丁质酶基因(chiA)编码区1.6kb全长片段,并将该片段分别克隆至原核表达载体pET30a和杆状病毒BactoBac表达系统转移载体pFastBac中,分别在大肠杆菌(Escherichia coli)BL21(DE3)和草地贪夜蛾(Spodoptera frugiperda)细胞系Sf-9中进行了表达。SDS-PAGE分析表明,在大肠杆菌和昆虫细胞中均有效表达了60kD的蛋白。将表达产物饲喂5龄棉铃虫(Helicoverpa armigera)幼虫后取其围食膜,扫描电镜结果显示,围食膜结构遭到破坏形成大量孔洞。生物测定结果表明,以上两种表达产物对苏云金芽孢杆菌(Bt)和核型多角体病毒(NPV)均具有增效作用。以AcMNPVChiA在大肠杆菌和细胞系Sf-9中的表达产物分别与BtCry2Ac蛋白混合饲喂棉铃虫初孵幼虫,增效率分别为33.4%和54.5%,其LT50较对照处理分别缩短了17.8和20.6h;当AcMNPVChiA在大肠杆菌和细胞系Sf-9中的表达产物分别与甘蓝夜蛾(Mamestra brassica)核型多角体病毒(MbNPV)混合处理棉铃虫初孵幼虫时,其LT50与对照比较分别缩短了16.6和22.4h。 相似文献
8.
Summary The effects of simulated acid rain and acidification combined with liming on enzymatic activities in the gut of the enchytraied Fridericia sp. were studied under laboratory conditions. Simulated mild (pH 4.4) and strong (pH 3.1) acid rain was applied throughout a 52-day experiment. Liming, at rates of 1500 and 4000 kg CaCO3 powder ha-1, was applied once on the 27th day of acid rain. After 52 days, the treatment effects were determined by analysing changes in the fresh body weight of enchytraeids and the activities of amylase (EC 3.2.1.1), xylanase (EC 3.2.1.8), trehalase (EC 3.2.1.28) and C1-cellulase (EC 3.2.1.91) in the gut. The effects were significant in only a few instances. After acidification, xylanase and trehalase activities decreased. The changes in fresh body biomass were not significant. Amylase and cellulase activities increased slightly, possibly because the acidification had a stimulatory effect on soil amylolytic and cellulolytic microorganisms. After liming, both xylanase activity and the enchytraeid body biomass decreased. This was the only marked evidence of a negative effect on the enchytraeids. The high amylase, trehalase and cellulase activities that were observed might have been caused by intensive digestion of dead acidophilous microflora. 相似文献
9.
10.
采用PCR方法扩增出苜蓿银纹夜蛾核型多角体病毒（AcMNPV）几丁质酶基因（chiA）编码区1.6kb全长片段,并将该片段分别克隆至原核表达载体pET30a和杆状病毒Bac to Bac表达系统转移载体pFastBac中,分别在大肠杆菌（E. coli）BL21(DE3)和草地贪夜蛾细胞系Sf-9中进行了表达。SDS-PAGE分析表明,在大肠杆菌和昆虫细胞中均有效表达了60kDa的蛋白。将表达产物饲喂5龄棉铃虫幼虫后取其围食膜,扫描电镜结果显示,围食膜结构遭到破坏形成大量孔洞。生物测定结果表明,以上两种表达产物对Bt和NPV均具有增效作用。以AcMNPV ChiA在大肠杆菌和细胞系Sf-9中的表达产物分别与Bt Cry2Ac蛋白混合饲喂棉铃虫幼虫,增效率分别为33.4％和54.5％,其LT50较对照处理分别缩短了17.8h和20.6h;当AcMNPV ChiA在大肠杆菌和细胞系Sf-9中的表达产物分别与甘蓝夜蛾核型多角体病毒（MbNPV）混合处理棉铃虫幼虫时,其LT50与对照比较分别缩短了16.6h和22.4h。 相似文献
11.
家蚕肠道产蛋白酶菌株的分离与鉴定及其发酵条件 总被引：1，自引：0，他引：1
为探明家蚕肠道中产蛋白酶细菌的种类分布及其作用效果,本研究以家蚕(Bombyx mori)4龄幼虫肠道内容物为材料,采用牛肉膏蛋白胨培养基和酪蛋白培养基分离筛选产蛋白酶细菌菌株,利用16SrDNA序列分析鉴定其种属,并研究其产酶能力和产酶活力较高菌株的最适发酵条件。结果获得3株产蛋白酶菌株皓月NA1、951NA3和951NA6,均归属于不动杆菌属(Acinetobacter),其中皓月NA1号细菌产酶能力最强,最佳产酶量为29.5U/mL。以玉米粉10000mg/L、黄豆粉10000mg/L、MgSO4400mg/L、NaC115000mg/L和K2HPO41000mg/L作为发酵培养基成分,在35℃、起始pH9.0、装液量为80mL/150mL、180r/min振荡培养48h的优化发酵条件下,皓月NA1号细菌最大产酶量可达50U/m L。研究结果对家蚕肠道微生物的分布及肠道益生菌的作用效果调控有着十分重要的意义。 相似文献
12.
电子束处理烟草甲末龄幼虫的辐照效应 总被引：6，自引：2，他引：6
利用不同剂量的电子束对烟草甲末龄幼虫进行辐照处理,研究电子束辐照对末龄幼虫42d内死亡率、完全致死时间、化蛹率和羽化率及繁殖能力的影响。结果表明,随辐照剂量的增加,末龄幼虫的死亡率逐渐上升,但并不是立即死亡,而是随继续饲养时间的延长而增加。幼虫完全致死时间随辐照剂量的增加而缩短,经480Gy以上剂量辐照的烟草甲幼虫不能羽化为成虫,经300Gy以上剂量辐照的烟草甲幼虫羽化出的成虫不能产生下一代成虫。综合考虑其他因素,300Gy的剂量可以作为阻止烟草甲末龄幼虫繁殖的有效辐照剂量。 相似文献
13.
Žiga Laznik Stanislav Trdan 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2013,63(2):95-108
White grubs are the root-feeding larvae of scarab beetles (Coleoptera: Scarabaeidae), and they are among the most destructive pests of turfgrass, pastures and horticultural plants in many parts of the world. A two-year field experiment was conducted to control different white grub species in an organically utilised meadow with dry forage conservation. The efficacy of Beauveria brongniartii, Beauveria bassiana, Bacillus thuringiensis var. kurstaki, B. thuringiensis var. tenebrionis and Heterorhabditis bacteriophora was tested against the white grubs in comparison with untreated control (only water suspension was used). The application of biological control agents was conducted twice (April and August). Our observations show that several biological control agents are capable of controlling the populations of the first and second instar larvae of different scarab grub species. The efficacy of most biological control agents, however, declines when larvae reach the third instar stage. The most promising combination tested in our study is that of entomopathogenic fungi and H. bacteriophora for controlling the first- and second-stage instar larvae. In addition, the summer application proved to be more suitable for control of the first-stage instar larvae than the spring application. 相似文献
14.
Characterization of two Acanthoscelides obtectus alpha-amylases and their inactivation by wheat inhibitors 总被引：1，自引：0，他引：1
Franco OL Melo FR Mendes PA Paes NS Yokoyama M Coutinho MV Bloch C Grossi-de-Sá MF 《Journal of agricultural and food chemistry》2005,53(5):1585-1590
Wheat alpha-amylase inhibitors represent an important tool in engineering crop plants against bean bruchids. Because Acanthoscelides obtectus is a devastating storage bean insect-pest, we attempted to purify and characterize its gut alpha-amylases, to study their interaction with active proteinaceous inhibitors. Two digestives alpha-amylases (AoA1 and AoA2) were purified from gut larvae, showing molecular masses of 30 and 45 kDa for each one, respectively. The stoichiometry interaction between these alpha-amylases with two wheat inhibitors (0.19 and 0.53) showed a binding complex of 1:1 enzyme:inhibitor. In vivo activities of these inhibitors against A. obtectus were also evaluated using a rich ammonium sulfate inhibitor fraction (F(20)(-)(40)) and purified inhibitors after reversed phase high-performance liquid chromatography columns. Incorporation of three different inhibitor concentrations (0.25, 0.5, and 1.0% w/w) into artificial seeds showed that addition of the purified 0.19 inhibitor at the highest concentration (1.0%) reduced the larval weight by 80%. Similar data were observed when 0.53 inhibitor was incorporated at 0.5%. When the concentration of purified 0.53 was enhanced to 1.0%, no larvae or adult emergence were observed. Our data suggest that these alpha-amylase inhibitors present great potential for use in Phaseolus genetic improvement programs. 相似文献
15.
The white grub (Ligyrus subtropicus (Blatchley)) is a major insect pest of Florida sugarcane (Saccharum spp.). The primary impact this insect has on the sugarcane plant is through larval feeding on plant roots and underground stems. A greenhouse study was conducted to evaluate the effect of L. subtropicus larval feeding on N, P, K, Ca, and Mg nutrition of sugarcane. Third instar L. subtropicus larvae were introduced to the soil at rates of 0, 2, 4, 6, and 8 larvae/plant. Leaf N, P, and K concentrations decreased linearly as the level of grub infestation increased. Leaf Ca and Mg concentrations were not affected by grub feeding. 相似文献
16.
Purification and characterization of ferulic acid esterase from malted finger millet (Eleusine coracana, Indaf-15) 总被引：2，自引：0，他引：2
Latha GM Srinivas P Muralikrishna G 《Journal of agricultural and food chemistry》2007,55(23):9704-9712
Ferulic acid esterase (EC 3.1.1.73) cleaves the feruloyl groups substituted at the 5'-OH group of arabinosyl residues of arabinoxylans and is known to modulate their functional properties. In this study, ferulic acid esterase from 96 h finger millet malt was purified to apparent homogeneity by three-step purification with a recovery of 3% and a fold purification of 22. The substrate p-nitrophenylferulate (PNPF) was synthesized and used to assay this enzyme spectrophotometrically. The products liberated from ragi and wheat water-soluble polysaccharides by the action of purified ragi ferulic acid esterase were identified by ESI-MS. The pH and temperature optima of the enzyme were found to be 6.0 and 45 degrees C, respectively. The pH and temperature stabilities of the enzyme were found to be in the range of 5.5-9.0 and 30 degrees C, respectively. The activation energy of the enzymatic reaction was found to be 4.08 kJ mol(-1). The apparent K m and V max of the purified ferulic acid esterase for PNPF were 0.053 microM and 0.085 unit mL(-1), respectively. The enzyme is a monomer with a molecular mass of 16.5 kDa. Metal ions such as Ni(2+), Zn(2+), Co(2+), and Cu(2+) and oxalic and citric acids enhanced the enzyme activity. The enzyme was completely inhibited by Fe(3+). Group specific reagents such as p-chloromercuric benzoate and iodoacetamide inhibited the enzyme, indicating the possible presence of cysteine residues in the active site pocket. 相似文献
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18.
Effects of water-soluble-fractions (WSFs) from No. 2 Fuel Oil on growth and reproduction in a laboratory strain of Neanthes arenaceodentata were studied in experiments simulating conditions of acute and chronic sublethal exposure. Effects were defined relative to concentrations of diaromatic hydrocarbons (naphthalenes) and total dissolved hydrocarbons. Hatching of metatrochophore larvae was inversely related to WSF concentration and to the length of time larvae were exposed prior to hatching. Growth of larvae into juveniles was unaffected by low concentrations. Inhibition of larval growth by higher WSF concentrations was reversible upon return of larvae to hydrocarbon-free sea water. Growth of juveniles into adult polychaetes was inversely related to concentration. Rate of development to the feeding juvenile stage was not affected by WSF in three successive generations of continuously exposed polychaetes. Oocyte maturation rates in the four WSF concentrations (2.5, 5, 10, 2507o) increased with each successive generation. All concentrations suppressed fecundity in each generation. Survival to the 32-segment juvenile stage (brood mortality) was inversely related to concentration in first generation animals. Brood mortality in all WSF concentrations decreased with successive generations thereafter. Levels of naphthalenes in worms declined with each generation. Naphthalenes concentrations in third generation animals was very similar to those of exposure media. 相似文献
19.
Biotransformation of alpha-terpineol by the common cutworm (Spodoptera litura) larvae was investigated. alpha-Terpineol was mixed in an artificial diet, and the diet was fed to the larvae (fourth-fifth instar) of S. litura. Metabolites were isolated from the frass and analyzed spectroscopically. Main metabolites were 7-hydroxy-alpha-terpineol (p-menth-1-ene-7,8-diol) and oleuropeic acid (8-hydroxy-p-menth-1-en-7-oic acid). Intestinal bacteria from the frass of larvae did not participate in the metabolism of alpha-terpineol. alpha-Terpineol was preferentially oxidized at the C-7 position (allylic methyl group) by S. litura larvae. 相似文献
20.
为探索乌蔹莓鹿蛾的人工饲养条件, 就幼虫饲养密度(每瓶1 头、3 头、5 头、7 头、9 头)和温度(25 ℃、28 ℃、31 ℃)对乌蔹莓鹿蛾的发育历期、存活率和取食等进行了研究。结果显示, 与群体饲养相比, 单头饲养的乌蔹莓鹿蛾幼虫的发育历期长, 成活率低, 取食量较大。在25~31 ℃的环境温度下, 乌蔹莓鹿蛾幼虫的发育历期随温度升高而缩短, 28~31 ℃较有利于幼虫生长发育, 28 ℃的存活率最高(79.47%), 31 ℃时幼虫取食量最大(2.45 g·头-1)。在人工饲养条件下, 初龄幼虫以3~5 头群体饲养为宜, 3 龄以后以单头饲养为宜, 饲养温度以28~31 ℃为宜。 相似文献