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1.
Y. Sato 《BioControl》1980,25(2):123-128
The growth and development ofApanteles glomeratus L. eggs and larvae in the host larva (Pieris rapae crucivora Boisduval) was investigated by calculating their volume. WhenA. glomeratus eggs increase 90 fold in volume after being laid, larvae hatch from them. The larvae grow exponentially and the growth rate of the parasitoid is dependent on the host stage. Being laid in the 1st instar host, the parasitoids grow more slowly than those laid in 2nd–4th instar host. A pupal host stage prevents the parasitoids’ development. When larvae exceed the threshold size of 5.0×108 μ3, they enter the 2nd instar. A few days after they attain the maximum size of 3.3×109 μ3, they moult and egress from the host body.  相似文献   

2.
Over a period of several years, the ecology of germination of the seeds ofAlliaria petiolata (M. Bieb.) Cavara etGrande has been studied, both in the laboratory and on an experimental plot at Průhonice. Using 11 seed samples collected in various regions of Czechoslovakia, experiments have shown that seeds of this species pass through a dormancy stage which is caused by physiological features of the embryo. Dormancy was interrupted in cold stratification at temperatures between +1 and +6°C. Germination started on between 60th and 97th day after the beginning of stratification, while, the majority of seeds germinated after 75 to 90 days.  相似文献   

3.
Phenolic compounds released during pretreatment of lignocellulosic biomass influence its enzymatic hydrolysis. To understand the effects of these compounds on the kinetic properties of xylan-degrading enzymes, the present study employed the recombinant cellulosomal endo-β-1,4-xylanase, thermostable GH11 XynA protein from Clostridium thermocellum, as an enzyme model to evaluate the effects of 4-hydroxybenzoic acid, gallic acid, vanillin, tannic acid, p-coumaric acid, ferulic acid, syringaldehyde, and cinnamic acid. XynA was deactivated by the assayed phenols at 60 °C, presenting the strongest deactivation in the presence of tannic acid, with an activity reduction of about 80 %. Thermal stability of XynA was influenced by ferulic acid, syringaldehyde, cinnamic acid, 4-hydroxybenzoic acid, and p-coumaric acid. The hydrolysis rate of oat-spelt xylan by XynA was influenced by temperature, being unable to hydrolyze at 40 °C in the presence of tannic acid. On hydrolysis at 60 °C, the presence of gallic and tannic acid caused a major reduction in reducing sugar production, generating 3.74 and 2.15 g.L-1 of reducing sugar, respectively, whereas the reaction in the absence of phenols generated 4.41 g.L-1. When XynA was pre-deactivated by phenols it could recover most of its activity at 40 °C, however, at 60 °C activity could not be reestablished.  相似文献   

4.
Abstract

A novel tannase and gallic acid-producing Penicillium rolfsii (CCMB 714) was isolated from cocoa leaves from the South of Bahia. The influence of nutritional sources and the simultaneous effect of parameters involved in the fermentation process were available. Tannase (9.97 U?mL?1) and gallic acid (9?mg mL?1) production were obtained in 48?h by submerged fermentation in non-optimized conditions. Among the carbon sources, tested gallic acid and tannic acid showed the highest tannase production (p<.05) when compared with methyl gallate and glucose. After optimization using the temperature and tannic acid concentration as variables with the Central Compound Rotational Design (CCRD), the maximal tannase production (25.6?U mL?1) was obtained at 29.8?°C and 12.7%, respectively, which represents an increase of 2.56 times in relation to the initial activity. The parameters optimized for the maximum production of gallic acid (21.51?mg mL?1) were 30?°C and 10% tannic acid. P. rolfsii CCMB 714 is a new strain with a high tannase and gallic acid production and the gallic acid produced is very important, mainly for its applications in the food and pharmaceutical industry.  相似文献   

5.
Diol synthase from Aspergillus nidulans was cloned and expressed in Escherichia coli. Recombinant E. coli cells expressing diol synthase from A. nidulans converted linoleic acid to a product that was identified as 5,8-dihydroxy-9,12(Z,Z)-octadecadienoic acid by liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS). The recombinant cells and the purified enzyme showed the highest activity for linoleic acid among the fatty acids tested. The optimal reaction conditions for the production of 5,8-dihydroxy-9,12(Z,Z)-octadecadienoic acid from linoleic acid using whole recombinant E. coli cells expressing diol synthase were pH 7.5, 35°C, 250 rpm, 5 g l?1 linoleic acid, 23 g l?1 cells, and 20% (v/v) dimethyl sulfoxide in a 250-ml baffled flask. Under these optimized conditions, whole recombinant cells expressing diol synthase produced 4.98 g l?1 5,8-dihydroxy-9,12(Z,Z)-octadecadienoic acid for 150 min without detectable byproducts, with a conversion yield of 99% (w/w) and a productivity of 2.5 g l?1 h?1. This is the first report on the biotechnological production of dihydroxy fatty acid using whole recombinant cells expressing diol synthase.  相似文献   

6.
A Gram-stain negative, short rod-shaped, non-motile, catalase- and oxidase-positive, aerobic bacterium, designated F14T, was isolated from the Western Pacific Ocean. Phylogenetic and phenotypic properties of the organism supported that it belongs to the genus Paracoccus. The levels of 16S rRNA gene sequences similarity between strain F14T and other type strains of recognized members of the genus Paracoccus were 93.6–96.5 %. Growth of strain F14T was observed at 4–40 °C (optimum, 28–30 °C), pH 6.0–10.0 (optimum, pH 7.0–8.0) and in the presence of 0–7 % (w/v) NaCl (optimum, 1–2 %). The major cellular fatty acid was summed feature 8 (C18:1 ω6c and/or C18:1 ω7c). The major respiratory quinone was ubiquinone-10. The polar lipid pattern indicated the presence of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine and three unknown lipids. The DNA G+C content was 61.4 mol%. On the basis of polyphasic characterization, strain F14T represents a novel species, for which the name Paracoccus pacificus sp. nov. is proposed. The type strain is F14T (=CGMCC 1.12755T=LMG 28106T=MCCC 1A09947T).  相似文献   

7.
For the first time, Cochliobolus lunatus strain CHR4D, a marine-derived ascomycete fungus isolated from historically contaminated crude oil polluted shoreline of Alang-Sosiya ship-breaking yard, at Bhavnagar coast, Gujarat has been reported showing the rapid and enhanced biodegradation of chrysene, a four ringed high molecular weight (HMW) polycyclic aromatic hydrocarbon (PAH). Mineral Salt Broth (MSB) components such as ammonium tartrate and glucose along with chrysene, pH and trace metal solution have been successfully optimized by Response Surface Methodology (RSM) using central composite design (CCD). A validated, two-step optimization protocol has yielded a substantial 93.10% chrysene degradation on the 4th day, against unoptimized 56.37% degradation on the 14th day. The results depict 1.65 fold increase in chrysene degradation and 1.40 fold increase in biomass with a considerable decrement in time. Based on the successful laboratory experiments, C. lunatus strain CHR4D can thus be predicted as a potential candidate for mycoremediation of HMW PAHs impacted environments.  相似文献   

8.
Cadmium contamination is a critical constraint to plant production in agricultural soils in some regions. Cerium is one of the rare earth elements, it plays a positive role in plant growth with a appropriate content. The present study was conducted to examine the role of cerium nutrition in the amelioration of effects on cadmium toxicity in rice (Oryza sativa L.) seedlings by a hydroponic experiment. Measurements included growth condition, photosynthesis related parameters, chloroplast ultra-structure and antioxidant enzymes content. Our results showed that the growth of rice seedlings was markedly inhibited by cadmium (100 μM), and the inhibition was significantly alleviated by cerium (10 μM). Fresh weight, single seedling height and chlorophyll content of rice plants in cerium treated groups were increased by 24.4, 18.2 and 32.05 % compared to those of plants cultivated in only cadmium-present condition. Additionally, in cadmium treated plants, the addition of cerium significantly increased the value of the maximum quantum yield of primary photochemistry (F v /F m ), indicator of PSII ‘structure and functioning’ (SFI ABS ) and the performance index on absorption basis (PI ABS ), elevated the activity of whole chain electron transport activity, enhanced photophosphorylation and its coupling factor Ca2+-ATPase activities. The result showed that the chloroplasts and thylakoid membrane of the rice seedlings leaves grown in cerium treatment developed better than that in cerium-absent group under cadmium toxicity. Moreover, addition with 10 μM cerium mitigated cadmium stress by inducing leaf enzyme activities for antioxidation like superoxide dismutase, peroxidase and catalase, dramatically depressed superoxide (O 2 ·? ), hydrogen peroxide and malondialdehyde accumulation. Results indicated that alleviation of cadmium toxicity by cerium application is partly related to improved light-use-efficiency, increased antioxidant enzymes, decreased oxidative stress in rice seedlings.  相似文献   

9.
A Gram-stain negative, short rod-shaped aerobic bacterium with flagella, designated strain Y32T, was isolated from coastal seawater in Xiamen, Fujian Province of China. 16S rRNA gene sequence comparisons showed that strain Y32T is a member of the family Oceanospirillaceae, forming a distinct lineage with species of the genus Litoribacillus. The 16S rRNA gene sequence similarities between strain Y32T and other strains were all less than 94.0 %. Strain Y32T was found to grow optimally at 28 °C, at pH 7.0–8.0 and in the presence of 4–5 % (w/v) NaCl. The major fatty acids were identified as Summed Feature 3 (comprising C16:1 ω7c and/or C16:1 ω6c, 49.4 %), C16:0 (17.7 %), C14:0 (6.9 %) and C18:1 ω9c (5.4 %). The major respiratory quinone was identified as ubiquinone-8 (Q-8). The major polar lipids were identified as diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. The DNA G+C content of strain Y32T was determined to be 55.6 mol%. According to its morphology, physiology, fatty acid composition, polar lipids composition and 16S rRNA gene sequence data, strain Y32T represents a novel species of a new genus in the family Oceanospirillaceae, for which the name Litoribrevibacter albus gen. nov. sp. nov. is proposed. The type strain of Litoribrevibacter albus is Y32T (=MCCC 1F01211T=NBRC 110071T).  相似文献   

10.
A novel thermophilic, Gram-staining positive bacterium, designated DX-2T, was isolated from the anode biofilm of a microbial fuel cell. Cells of the strain were oxidase positive, catalase positive, facultative anaerobic, motile rods. The isolate grew at 30–60 °C (optimum 50 °C) and pH 5–9 (optimum pH 8–8.5). The pairwise 16S rRNA gene sequence similarities showed that strain DX-2T was most closely related to Bacillus fumarioli LMG 17489T (96.2 %), B. firmus JCM 2512T (96.0 %) and B. foraminis DSM 19613T (95.7 %). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain DX-2T formed a cluster with B. smithii (95.5 %) and B. infernus (94.9 %). The genomic G+C content of DX-2T was 43.7 mol%. The predominant respiratory quinone was MK-7. The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and unknown phospholipids. The major cellular fatty acid was iso-C16:0. Based on its phenotypic characteristics, chemotaxonomic features, and results of phylogenetic analysis, the strain was identified to represent a distinct novel species in the genus Bacillus, and the name proposed is B. thermophilum sp. nov. The type strain is DX-2T (=CCTCC AB2012194T = KCTC 33128T).  相似文献   

11.
A low-molecular-weight cadmium-binding protein was induced in the livers of rainbow trout (Salmo gairdnerii) following a series of intraperitoneal injections of cadmium chloride. The subsequent purification and amino acid analysis of this protein showed it to be a true metallothionein. As in higher organisms, two major forms of metallothionein appeared to be present in the liver following cadmium treatment. Following a similar induction procedure total RNA was also isolated and shown to contain high levels of metallothionein-mRNA activity when assayed in a wheat-germ cell-free translation system. This activity was present in the Poly-A+-containing fraction of the total RNA. The bulk of this mRNA activity was shown to be in the 8–10S region of a sucrose gradient.  相似文献   

12.
A Gram-negative bacterial strain, designated WB1T, was isolated from a domestic refrigerator in Guangzhou, PR China. Cells of strain WB1T were oxidase-negative, catalase-positive, strictly aerobic, non-spore-forming and non-motile coccobacilli with peritrichous fimbriae-like structures. The strain was able to grow at 10–40 °C with optimum growth at 28–30 °C, pH 6.0–8.0 (optimum, pH 7.0) and 0–6 % NaCl (w/v, optimum, 0.5 %). Phylogenetic analyses based on 16S rRNA gene and rpoB gene sequences revealed that strain WB1T belonged to the genus Acinetobacter and was most closely related to A. indicus DSM 25388T (97.2 % 16S rRNA gene sequence similarity) and A. radioresistens NBRC 102413T (96.8 %). The DNA G + C content of strain WB1T was 46.74 ± 0.04 mol % and the major fatty acids comprised summed feature 3 (C16:1 ω7c and/or C16:1 ω6c), C18:1 ω9c, C16:0 and C12:0. The predominant respiratory quinone was identified as Q-9 and the polar lipids as diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine and an unidentified phospholipid. Phenotypic, phylogenetic and chemotaxonomic data, including low DNA–DNA relatedness with closely related type strains, supported that strain WB1T represents a distinct novel species in the genus Acinetobacter, for which the name Acinetobacter refrigeratorensis sp. nov. was proposed. The type strain is WB1T (=GIMCC 1.663T = CCTCC AB 2014197T = KCTC 42011T).  相似文献   

13.
Tunisian microalgae are diverse and rarely been studied. This study reports a first investigation of thermophile Chlorophyta isolated from mats community colonizing the geothermal springs in the north of Tunisia at water temperature 60 °C. In the study, the combined effect of temperature and light intensity was investigated on the cell growth, the mother and daughter cells abundance and the extracellular polymeric substances synthesis in batch culture of the isolated species. Three levels were tested for each factor, 20, 30, 40 °C for temperature; and 20, 70, 120 μmol photons m?2 s?1 for light intensity, using full factorial design and response surface methodology. The thermophile strain was identified as a genus Graesiella and showed 99.8 % similarity with two Graesiella species: Graesiella emersonii and Graesiella vacuolata based on the 18S rDNA molecular identification. The optimal growth condition was found at 30 °C and 120 µmol photons m?2 s?1 (7 MC mL?1 day?1), with the abundance of vegetative cells (daughter cells). In contrast, the number of mother cells increased significantly as the growth decreased; consequently, the highest ratio of auto spore mother cells versus daughter cells (19.4) was obtained at 20 °C and 20 µmol photons m?2 s?1. The highest yield of EPS production (11.7 mg L?1 day?1) was recorded at the highest temperature (40 °C) and lowest light intensity (20 µmol photons m?2s?1). These results revealed how the species respond to high and low temperatures and suggest that the species should be considered as facultative thermophile.  相似文献   

14.
An aerobic, Gram-staining negative, non-motile, and rod-shaped bacterial strain, SS011A0-7#2-2T, was isolated from the sediment of South China Sea with the depth of 1,500 m. Optimum growth occurred at pH 8.0, 30 °C, and 6 % (w/v) NaCl. Strain SS011A0-7#2-2T did not synthesize bacteriochlorophyll a or carotenoid, neither possess photosynthesis genes. Its genome DNA G+C content was 67.9 mol%. It contained Q-10 as the predominant ubiquinone and C18:1 ω7c (52.3 %) as the major fatty acid. The major polar lipids were phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, unidentified phospholipid, and unidentified aminolipid. The 16S rRNA gene sequence analysis revealed that it was closely related to Seohaeicola saemankumensis SD-15T, Phaeobacter gallaeciensis BS 107T and Roseovarius pacificus 81-2T in Rhodobacteraceae, with the 16S rRNA gene sequence similarities being 96.5, 95.7, and 95.6 %, respectively. However, the phylogeny of the 16S rRNA gene sequences revealed that strain SS011A0-7#2-2T was a member of the genus Seohaeicola. Strain SS011A0-7#2-2T was moderately halophilic which was different from Seohaeicola saemankumensis SD-15T, and it showed the enzyme activities and carbon source spectrum significantly different from Seohaeicola saemankumensis SD-15T. As its physiological and chemotaxinomic properties were different from those of Seohaeicola saemankumensis SD-15T, strain SS011A0-7#2-2T represents a novel species of the genus Seohaecola. The name Seohaeicola nanhaiensis sp. nov. is proposed, with strain SS011A0-7#2-2T (=LMG 27733T = CGMCC 1.12759T) as the type strain.  相似文献   

15.
Ralstonia paucula strain RA4T, a gram negative, non-spore forming, motile bacterium having positive catalase and oxidase test, was isolated from surface soil. Twin arginine translocation protein type D (TatD) is shown to be located in cytoplasm and exhibits magnesium-dependent DNase. A tatD DNase gene was isolated and cloned from Ralstonia paucula RA4T genome. Nucleotide sequence analysis of the gene revealed 813 nucleotides encoding a protein of 270 amino acid residues. The tatD gene showed a high similarity to homolog gene from Ralstonia pickettii strain 12D. The deduced polypeptide sequence of TatD DNase from R. paucula RA4T had a typical catalytic site, HHPLDEHRHDP, and its calculated molecular mass and predicted isoelectric point were 29616 Da and 5.33, respectively. The deduced amino acid sequence showed a high degree of similarity to TatD DNase isoforms from Ralstonia genus and other sources. Predicted three-dimensional structure of TatD confirmed the presence of active site and theoretical function as DNase.  相似文献   

16.
C. Peter  B. V. David 《BioControl》1991,36(3):403-407
Goniozus sensorius Gordh (Hymenoptera: Bethylidae) was recorded as a major parasite of the pumpkin caterpillar,Diaphania indica (Saunders) (Lepidoptera: Pyralidae). This paper provides detailed information on the oviposition behaviour ofG. sensorius. Prior to oviposition, the parasite temporarily paralyses the host larva. The paralysed condition lasts for about 2 h. The egg laying process on each larva requires 30 to 60 min. The maximum number of eggs are laid on the 6th and 7th segment, and none in the terminal segments. Generally, oviposition is restricted to 1 segment of the host larva and occasionally on 3 segments. The maximum number of eggs are laid on the 2nd and 3rd day after emergence and the mean number of eggs laid on each host larva was 7.1.  相似文献   

17.
A Gram-positive, moderately halotolerant, rod-shaped, spore forming bacterium, designated strain FJAT-14515T was isolated from a soil sample in Cihu area, Taoyuan County, Taiwan. The strain grew at 10–35 °C (optimum at 30 °C), pH 5.7–9.0 (optimum at pH 7.0) and at salinities of 0–5 % (w/v) NaCl (optimum at 1 % w/v). The diagnostic diamino acid of the peptidoglycan of the isolated strain was meso-diaminopimelic acid and major respiratory isoprenoid quinone was MK-7. Major cellular fatty acids were anteiso-C15:0 (40.6 %), iso-C15:0 (20.7 %) and the DNA G+C content of strain FJAT-14515T was 37.1 mol %. A phylogenetic analysis based on 16S rRNA gene sequences indicated that strain FJAT-14515T belongs to the genus Bacillus, and was most closely related to the reference strains of Bacillus muralis DSM 16288T (97.6 %) and Bacillus simplex DSM 1321T (97.5 %). Levels of DNA–DNA relatedness between strain FJAT-14515T and the reference strains of B. muralis DSM 16288T and B. simplex DSM 1321T were 27.9 % ± 3.32 and 44.1 % ± 0.57, respectively. Therefore, on the basis of phenotypic, chemotaxonomic and genotypic properties, strain FJAT-14515T represents a novel species of the genus Bacillus, for which the name Bacillus cihuensis sp. nov. is proposed. The type strain is FJAT-14515T (=DSM 25969T = CGMCC 1.12697T).  相似文献   

18.
α-Mannosidase (EC. 3.2.1.114) belonging to class II glycosyl hydrolase family 38 was purified from Moringa oleifera seeds to apparent homogeneity by conventional protein purification methods followed by affinity chromatography on Con A Sepharose and size exclusion chromatography. The purified enzyme is a glycoprotein with 9.3 % carbohydrate and exhibited a native molecular mass of 240 kDa, comprising two heterogeneous subunits with molecular masses of 66 kDa (α-larger subunit) and 55 kDa (β-smaller subunit). Among both the subunits only larger subunit stained for carbohydrate with periodic acid Schiff’s staining. The optimum temperature and pH for purified enzyme was 50 °C and pH 5.0, respectively. The enzyme was stable within the pH range of 3.0–7.0. The enzyme was inhibited by EDTA, Hg2+, Ag2+, and Cu2+. The activity lost by EDTA was completely regained by addition of Zn2+. The purified enzyme was characterized in terms of the kinetic parameters K m (1.6 mM) and V max (2.2 U/mg) using para-nitrophenyl-α-D-mannopyranoside as substrate. The enzyme was very strongly inhibited by swainsonine (SW) at 1 μM concentration a class II α-Mannosidase inhibitor, but not by deoxymannojirimycin (DMNJ). Chemical modification studies revealed involvement of tryptophan at active site. The inhibition by SW and requirement of the Zn2+ as a metal ion suggested that the enzyme belongs to class II α-Mannosidase.  相似文献   

19.
Lysosome-solubilized pig liver NADH-cytochrome b5 reductase is inactivated by 5′-p-fluorosulfonylbenzoyladenosine (5′-FSBA) following pseudo-first-order kinetics. A double reciprocal plot of 1/K obs versus 1/[5′-FSBA] yields a straight line with a positiveY intercept, indicative of reversible binding of the analogue prior to an irreversible incorporation.K d or the initial reversible enzyme-analogue complex is estimated at 185 µM withK 2=0.22 min?1 (atpH 8.0 and 25°C). A stoichiometry of 1.2 moles of analogue bound/mole of enzyme at 100% inactivation has been determined from incorporation studies using 5′-p-fluorosulfonylbenzoyl-[14C]adenosine. The irreversible inactivation as well as the covalent incorporation could be completely prevented by the presence of NADH, the substrate of enzyme, during the incubation. Four 5′-FSBA-labeled peptides were isolated by reverse-phase high-performance liquid chromatography of tryptic digest of the modified NADH-cytochrome b5 reductase and their amino acid sequences were determined. These peptides appear to be related to the NADH binding site of the enzyme.  相似文献   

20.
Larvae of noctuids were inoculatedper os with spores of a species ofPleistophora isolated fromAgrotis exclamationis (L.). The mean median lethal dose for mainly 3rd instar larvae ofA. exclamationis was 1.38×105 spores per larva accumulating 34 or 35 days after inoculation and the mean slope for the regression of mortality on dose was 0.82. Third instar larvae ofA. exclamationis andSpodoptera frugiperda (J.E. Smith) inoculated with 2.5×104 spores gained weight quicker than uninfected ones until between 8 days (A. exclamationis) and 13 days (S. frugiperda) post-inoculation. Thereafter they grew slower than uninfected individuals. Correspondingly, the feeding rate of inoculated larvae ofA. exclamationis was greater than that of untreated ones until 14 days post-inoculation but thereafter was less. Larvae ofNoctua pronuba (L.)Phlogophora meticulosa L. andSpodoptera littoralis (Boisduval) but notAgrotis segetum (Denis & Schiffermüller) were also susceptible to infection. The species ofPleistophora considered here corresponds toP. schubergi noctuidae (Veremtchuk & Issi) in spore morphology, tissue specificity and host range, except that is was non-infective for the typehostA. segetum. It is probably insufficiently pathogenic for use in the biological control of noctuids.  相似文献   

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