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1.
The composition of aroma compounds in cooked and canned cepe (Boletus edulis) and in cooked oyster mushrooms (Pleurotus ostreatus) is studied using capillary gas chromatography and chromatographymass spectrometry. It is found that unsaturated alcohols and ketones containing eight atoms of carbon determine the aroma of raw mushrooms and take part in the formation of the aroma of cooked mushrooms as well. The content of these compounds was the highest in canned cepes. In oyster mushrooms, the concentration of these alcohols and ketones was lower in comparison with cepes. The content of aliphatic and aromatic aldehydes was much higher in oyster mushrooms. Volatile aliphatic and heterocyclic Maillard reaction products and isomeric octenols and octenones formed the aroma of cooked and canned mushrooms.  相似文献   

2.
Rhinusa pilosa (Gyllenhal) is a highly specific weevil that induces stem galls on the common toadflax Linaria vulgaris Mill. females oviposit the eggs near the apex of a growing shoot. The act of oviposition is accompanied by secretion of an ovipositional fluid, which is considered to be cecidogen, directly involved in gall induction. The remains of cecidogenic fluid were collected from the surface of the oviposition point on the stem. We performed a comparative analysis of the phenolics extracted from cecidogen, the stem and galls of L. vulgaris and adult and larva of R. pilosa by HPLC-DAD. One compound with A max at 273, 332 nm (R t 30.65 min) was exclusively found in the methanol extract of cecidogen. To further characterize the cecidogen and stem phenolic profiles, we used UHPLC coupled with an OrbiTrap mass analyzer. Among 49 phenolic compounds extracted from both the ovipositional fluid and the plant, protocatechuic acid and two phenolic glycosides were exclusively found in cecidogen: diosmetin-O-acetylrutinoside and an unidentified compound. The unknown compound produced an MS2 base peak at 387 and 327 and 267 m/z base peaks at MS3 and MS4 fragmentation, respectively, and had the molecular formula C32H31O18. The plausible role of phenolic compounds in the induction of gall formation on L. vulgaris is discussed.  相似文献   

3.
Allelopathy is very important for the scientific disposition of garden plants. To understand the allelopathic potential of Koelreuteria bipinnata Franch. var. integrifoliola, the germination of Agrostis tenuis Sibth., Festuca arundinacea Schreb. and Lolium perenne L. were determined under laboratory conditions. The results showed that root, stem and leaf aqueous extracts of K. bipinnata var. integrifoliola had allelopathic effects on all three turf grasses, and the allelopathic activity varied according to extract concentrations, test species, and extract sources. Lower extract concentrations did not affect or promoted the germination and initial seedling growth of turf grasses, but the highest concentrations almost had inhibitory effect. The order of allelopathic potentials of the three organs on germination of these receptors was root < stem < leaf. And at the highest concentration of leaf extract, the most strongly inhibition was found in A. tenuis, followed by F. arundinaces and then L. perenne. In addition, according to gas chromatography–mass spectrometry (GC–MS) analysis, the allelopathic potential compounds and their abundance in root, stem and leaf were obviously different. Therefore, the allelopathic compounds may responsible for allelopathy of K. bipinnata var. integrifoliola. These findings suggested that more attention should be paid to the leaf of K. bipinnata var. integrifoliola for the relative higher allelopathic effects.  相似文献   

4.
Bolete Productivity of Cistaceous Scrublands in Northwestern Spain. Cistaceous scrublands dominated by Cistus ladanifer and Halimium lasianthum are widely distributed in northwestern Spain and are known to harbor the popular edible mushrooms Boletus edulis and B. aereus. As commercial harvest of these species is an important activity in Spain’s forests, in some cases generating greater revenue than timber production, we tried to determine whether there is commercial potential for bolete harvest in young cistaceous scrublands. Transects of 50 m × 2 m were randomly established in cistaceous scrublands and bolete yield was measured. High production of these valuable mushrooms was associated with 3-year-old plants, a much earlier onset than observed for Pinus and Quercus stands. Management recommendations for the studied scrub ecosystems are proposed that take into account the economic value of the mushrooms.  相似文献   

5.
Sixty-eight bacterial cultures were isolated from 5 archaeological soils in Egypt. It is necessary to characterize bacteria from ancient temples to develop protection programs for such archaeological places. Purified bacterial cultures were then tested for their capability to inhibit some multi-drug resistant (MDR) pathogenic bacteria including Staphylococcus aureus, Listeria monocytogenes, Bacillus cereus, Escherichia coli and Klebsiella pneumoniae. Among the most active 10 antibacterial isolates, only one isolate designated as S5I4 was selected, characterized and identified as belonging to Bacillus amyloliquefaciens. The strain identification was confirmed by amplification of its 16S rRNA gene. The partial nucleotide sequence of the amplified 16S rRNA gene of the tested strain was submitted in GenBank with accession number AB813716. The physical and nutritional parameters were optimized to improve the production of antimicrobial agents by the B. amyloliquefaciens S5I4. The maximum antagonistic effect of this strain against the tested MDR pathogenic bacteria was achieved in presence of 1% galactose and 0.5% yeast extract at 37°C and pH 7.0 after 48 h incubation. The antibacterial compounds of B. amyloliquefaciens S5I4 were extracted, purified and characterized using spectroscopic analysis (IR, UV, proton NMR and MS). The compound having inhibitory activity was identified as butanedioic acid, octadecyl,1(1carboxy1methylethyl) 4octyl ester.  相似文献   

6.
Variability of M. arvensis from five geographically distanced populations was examined using morphological traits and phytochemical composition of essential oil and with the help of DNA fingerprinting using ISSR markers. The population differentiation based on morphological traits was weak. Analysis of the essential oil composition provided the subdivision of the sample into three groups and, on the basis of the composition of ISSR amplicons, into four groups of specimens. A high degree of genetic polymorphism of M. arvensis and substantial, though incomplete, population differentiation were identified. It was demonstrated that the population of M. arvensis from the Komi Republic was the most genetically isolated, while the populations from Moscow and Penza provinces were weakly differentiated from each other. The population from the Republic of Belarus (near Grodno) was genetically and phytochemically considerably different from the other studied populations, although morphologically indistinguishable from them. We argue that the differentiation was caused not only by the isolation by distance but also owing to the formation of three different ecotypes adapted to different climatic conditions.  相似文献   

7.
A strain of the fungus Gliocladium roseum YMF1.00133 was found to secrete nematicidal metabolites against nematodes Panagrellus redivivus, Caenothabditis elegans and Bursaphelenchus xylophilus in experiments searching for nematicidal fungi. Through bioassay-guided fractionations, a unique trioxopiperazine alkaloid, gliocladin C (compound 1), and an alkylane resorcinol, 5-n-heneicosylresorcinol (compound 2) were obtained from the methanol extract of the fungus and determined by single-crystal X-ray analysis and spectroscopic data. In vitro immersion experiments showed that the ED50 values of compounds 1 and 2 after 24 h incubation were 15 and 30 μg/mL against C. elegans, 50 and 80 μg/mL against P. redivivus, and 200 and 180 μg/mL against B. xylophilus, respectively. The X-ray diffraction data of compound 1 and the nematicidal activity of compounds 1 and 2 were reported for the first time.  相似文献   

8.
Amanita ponderosa is a specie of wild edible mushrooms growing spontaneously in some Mediterranean microclimates, namely in Alentejo and Andaluzia, in the Iberian Peninsula. The nutritional values of these fungi make them highly exportable. Due to the wide diversity of mushrooms in nature, it is essential to differentiate and to identify the various edible species. RAPD markers have been used as a valuable tool to distinguish the different genotypes, although this method has not yet been used toAmanita ponderosa. Two methods were used to establish different genetic fingerprinting patterns of edible mushrooms. Samples ofAmanita ponderosa were collected in six different regions of the southwest of the Iberian Peninsula and compared by RAPD-PCR and MSP-PCR. Additionally, to compare molecular profiles with others genera of edible mushrooms, three species of Basidiomycetes (Pleurotus ostreatus, Lactarius deliciosus andCoriolus versicolor) and an Ascomycete were used. Results showed that some molecular markers discriminate among an Ascomycete from Basidiomycetes (Amanita ponderosa, Pleurotus ostreatus, Lactarius deliciosus andCoriolus versicolor) and discriminate among the different genera within basidiomycetes, as it is expected. Moreover, OPF-6, OPG-2, OPG3 and M13 primes allowed to unravel a level of genetic polymorphism withinAmanita ponderosa mushrooms collected from different geographic origin.  相似文献   

9.
L-Lactate cytochrome c oxidoreductase (flavocytochrome b 2, FC b 2) from the thermotolerant methylotrophic yeast Hansenula polymorpha (Pichia angusta) is, unlike the enzyme form baker’s yeast, a thermostable enzyme potentially important for bioanalytical technologies for highly selective assays of L-lactate in biological fluids and foods. This paper describes the construction of flavocytochrome b 2 producers with over-expression of the H. polymorpha CYB2 gene, encoding FC b 2. The HpCYB2 gene under the control of the strong H. polymorpha alcohol oxidase promoter in a plasmid for multicopy integration was transformed into the recipient strain H. polymorpha C-105 (grc1 catX), impaired in glucose repression and devoid of catalase activity. A method was developed for preliminary screening of the transformants with increased FC b 2 activity in permeabilized yeast cells. The optimal cultivation conditions providing for the maximal yield of the target enzyme were found. The constructed strain is a promising FC b 2 producer characterized by a sixfold increased (to 3 μmol min?1 mg?1 protein in cell-free extract) activity of the enzyme.  相似文献   

10.
11.
Bioenergetics of the aerobic bacteriochlorophyll a-containing (BCl a) bacterium (ABC bacterium) Roseinatronobacter thiooxidans is a combination of photosynthesis, oxygen respiration, and oxidation of sulfur compounds under alkaliphilic conditions. The photosynthetic activity of Rna. thiooxidans cells was established by the photoinhibition of cell respiration and reversible photobleaching discoloration of the BCl a of reaction centers (RC), connected by the chain of electron transfer with cytochrome c 551 oxidation. The species under study, like many purple bacteria and some of the known ABC bacteria, possesses a light-harvesting pigment-protein (LHI) complex with the average number of 30 molecules of antenna BCl a per one photosynthetic RC. Under microaerobic growth conditions, the cells contained bc 1 complex and two terminal oxidases: cbb 3-cytochrome oxidase and the alternative cytochrome oxidase of the a 3 type. Besides, Rna. thiooxidans was shown to have several different soluble low- and high-potential cytochromes c, probably associated with the ability of utilizing sulfur compounds as additional electron donors.  相似文献   

12.

Objectives

To find a novel host for the production of 4-vinylphenol (4VPh) by screening Streptomyces species.

Results

The conversion of p-coumaric acid (pHCA) to 4VPh in Streptomyces mobaraense was evaluated using a medium containing pHCA. S. mobaraense readily assimilated pHCA after 24 h of cultivation to produce 4VPh. A phenolic acid decarboxylase, derived from S. mobaraense (SmPAD), was purified following heterologous expression in Escherichia coli. SmPAD was evaluated under various conditions, and the enzyme’s kcat/Km value was 0.54 mM ?1 s?1. Using intergenetic conjugation, a gene from Rhodobacter sphaeroides encoding a tyrosine ammonia lyase, which catalyzes the conversion of l-tyrosine to p-coumaric acid, was introduced into S. mobaraense. The resulting S. mobaraense transformant produced 273 mg 4VPh l?1 from 10 g glucose l?1.

Conclusion

A novel strain suitable for the production of 4VPh and potentially other aromatic compounds was isolated.
  相似文献   

13.
The cytochrome b 6 f complex of oxygenic photosynthesis produces substantial levels of reactive oxygen species (ROS). It has been observed that the ROS production rate by b 6 f is 10–20 fold higher than that observed for the analogous respiratory cytochrome bc1 complex. The types of ROS produced (O2??, 1O2, and, possibly, H2O2) and the site(s) of ROS production within the b 6 f complex have been the subject of some debate. Proposed sources of ROS have included the heme b p , PQ p ?? (possible sources for O2??), the Rieske iron–sulfur cluster (possible source of O2?? and/or 1O2), Chl a (possible source of 1O2), and heme c n (possible source of O2?? and/or H2O2). Our working hypothesis is that amino acid residues proximal to the ROS production sites will be more susceptible to oxidative modification than distant residues. In the current study, we have identified natively oxidized amino acid residues in the subunits of the spinach cytochrome b 6 f complex. The oxidized residues were identified by tandem mass spectrometry using the MassMatrix Program. Our results indicate that numerous residues, principally localized near p-side cofactors and Chl a, were oxidatively modified. We hypothesize that these sites are sources for ROS generation in the spinach cytochrome b 6 f complex.  相似文献   

14.
Changes in the levels of secondary compounds can trigger plant defenses. To identify phenolic compounds induced by Bemisia tabaci Middle East-Asia Minor 1 (MEAM1) in tobacco (Nicotiana tobacco L.), the content changes of 11 phenolic compounds in plants infested by B. tabaci MEAM1 or Trialeurodes vaporariorum were compared. The chlorogenic acid, catechin, caffeic acid, p-coumaric acid, rutin, and ferulic acid contents in B. tabaci MEAM1-infested tobacco plants increased significantly, having temporal and spatial effects, compared with uninfested control and T. vaporariorum infested plants. The contents were 4.10, 2.84, 2.25, 3.81, 1.46, and 1.91 times higher, respectively, than those in the control. However, a T. vaporariorum nymphal infestation just caused smaller chlorogenic acid, catechin, caffeic acid, and rutin contents increase, which were 2.33, 2.13, 1.59, and 3.19 times higher, respectively, than those in the control. In B. tabaci MEAM1 third-instar nymph-infested plants, chlorogenic acid, catechin, caffeic acid, and rutin increased more significantly in systemic than in local leaves. Salicylate-deficient plants inhibited the induction of the content of 10 phenolic compounds, but not caffeic acid, after a B. tabaci MEAM1 nymphal infestation. Thus, the elevated levels of phenolic compounds induced by B. tabaci MEAM1 were correlated with the salicylic acid signaling pathway and induced the responses of defense-related phenolic compounds.  相似文献   

15.
16.
The chemical composition of water-ethanol extracts of the brown algae Laminaria cichorioides, Costaria costata, and Fucus evanescens were studied. The extracts contained mannitol, iodine, micro elements, free amino acids, glycolipids, polyunsaturated fatty acids, fucosterine, and polyphenols. The extracts were distinguished by high contents of mannitol and iodine (L. cichorioides), lipophilic matter (C. costata), and polyphenol compounds (F. evanescens). All the extracts under study inhibited the growth of DLD-1 and HT-29 human intestine tumor cells. The strongest inhibitory effect was exerted by the extract of F. evanescens at a concentration of 50 μg/ml. The extracts can be recommended for the production of fucosterol, phlorotannins, chlorophyll derivatives, mannitol, and compositions for medical and veterinary application.  相似文献   

17.
Volatile phenols are aromatic compounds produced by some yeasts of the genus Brettanomyces as defense against the toxicity of hydroxycinnamic acids (p-coumaric acid, ferulic acid and caffeic acid). The origin of these compounds in winemaking involves the sequential action of two enzymes: coumarate decarboxylase and vinylphenol reductase. The first one converts hydroxycinnamic acids into hydroxystyrenes, which are then reduced to ethyl derivatives by vinylphenol reductase. Volatile phenols derived from p-coumaric acid (4-vinylphenol and 4-ethylphenol) have been described as the major contributors to self-defeating aromas associated with stable, gouache, wet mouse, etc., which generates large economic losses in the wine industry. The gene responsible for the production of 4-vinylphenol from p-coumaric acid has been identified as PAD1, which encodes a phenylacrylic acid decarboxylase. PAD1 has been described for many species, among them Candida albicans, Candida dubliniensis, Debaryomyces hansenii and Pichia anomala. In Brettanomyces bruxellensis LAMAP2480, a 666 bp reading frame (DbPAD) encodes a coumarate decarboxylase. Recent studies have reported the existence of a new reading frame belonging to DbPAD called DbPAD2 of 531 bp, which could encode a protein with similar enzymatic activity to PAD1. The present study confirmed that the transformation of Saccharomyces cerevisiae strain BY4722 with reading frame DbPAD2 under the control of the B. bruxellensis ACT1 promoter, encodes an enzyme with coumarate decarboxylase activity. This work has provided deeper insight into the origin of aroma defects in wine due to contamination by Brettanomyces spp.  相似文献   

18.
The purpose of this research was to develop microemulsions (ME) and microemulgels (MG) for enhancing transdermal delivery of Kaempferia parviflora (KP) extract. The methoxyflavones were used as markers. Various formulations of ME and MG containing 10% w/v KP extract were prepared, and the in vitro skin permeation and deposition were investigated. The potential ME system containing oleic acid (5% w/v), Tween 20 (20% w/v), PG (40% w/v), and water (35% w/v) was successfully formulated. ME with 10% w/v limonene (ME-L10%) showed higher methoxyflavones flux than ME-L5%, ME-L1%, ME without limonene, and KP extract in water, respectively. ME-L10% was selected for adding a gelling agent to form microemulgels (MG-L10%). However, the high viscosity of the gel formulation might control the diffusion of the compound from gel layer into the skin. Therefore, the liquid formulation provided potential ME droplets to deliver KP extract through the skin. Limonene also plays an effective role on the skin permeation, in which the histological image of the skin treated with ME-L10% exhibited larger space of each flattened keratinocyte layer in the stratum corneum compared to the skin treated with KP extract in water. Moreover, ME-L10% showed good stability. Therefore, ME-L10% was a potential formulation for improving transdermal delivery of KP extract.  相似文献   

19.
Most wakame Undaria pinnatifida, a brown algae, products are made from the frond portion. In this study, the polysaccharide content and antioxidant property of aqueous extract solutions (AESs) of the four parts (frond: wakame, stem of the frond: kuki-wakame, sporophyll: mekabu, and kuki-mekabu) of wakame were investigated. Polysaccharide content was high in both the wakame and mekabu. Superoxide anion (O2 ?) radical-scavenging capacities were high in the mekabu. These AESs could be fermented by Lactobacillus plantarum Sanriku-SU7. The O2 ? radical-scavenging activity of the kuki-wakame, mekabu, and kuki-mekabu were increased by the fermentation. Fermented mekabu clearly showed a protective effect on human enterocyte-like HT-29-luc cells and in a mouse model of dextran sodium sulphate-induced inflammatory bowel disease (IBD). These results suggest that the mekabu fermented by L. plantarum Sanriku-SU7 has anti-IBD effect related to O2 ? radical-scavenging.  相似文献   

20.
The effect of crude extract (Ce), seed coating agent (SCA) and whole bacterial broth culture (WBC) of Lysobacter strains was evaluated against the causal agent of clubroot formation in Cruciferous vegetables. The ability of four Lysobacter strains (L. antibioticus 6-B-1, L. antibioticus 6-T-4, L. antibioticus 13-B-1 and L. capsici ZST1-2) inhibited Plasmodiophora brassicae of resting spores and disease. Application of WBC of four Lysobacter strains inhibited clubroot disease, indicating that the disease suppression was due to antifungal compounds produced by the biocontrol bacterium in the culture. Development of clubroot on Chinese cabbage was inhibited when the WBC and SCA were applied before P. brassicae inoculation. Crude extract (Ce) of culture filtrate was effective in arresting the germination of resting spores of P. brassicae on slides. However, Lysobacter strains differed in their biocontrol effects, the strain L. capsci ZST1-2 recorded a high level of disease limiting effect.  相似文献   

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