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1.
Aissaoui H  Agut M  Calvo Torras MA 《Microbios》1999,100(396):109-116
Poultry feed contains a significant reservoir of bacteria and is a possible source of Salmonella typhimurium, Staphylococcus aureus and Escherichia coli, which can potentially infect farm animals and humans. The objective of this study was to determine whether the extract obtained from the culture of some Arthrinium species was able to inhibit the growth of these bacteria. The results obtained showed that the raw extracts of Arthrinium aureum, Arthrinium serenensis and Arthrinium phaeospermum inhibited the growth of Escherichia coli in poultry feed. In some cases the percentage inhibition of the growth of Escherichia coli was > 80%. With the raw extract of Arthrinium in poultry feed, the rate of growth of S. typhimurium fell to between 50% and 80%. The raw extract of A. serenensis had the lowest inhibitory activity. S. aureus counts were not affected by any Arthrinium raw extracts.  相似文献   

2.
Water extracts of pea and soybean stimulated the growth of five tested gas-producing Clostridium strains. When pea and soybean tempeh extracts were used the inhibition effect took place. It is postulated that an antibacterial compound is formed during tempeh fermentation. The stimulating effect might be connected with flatus formation by legumes.  相似文献   

3.
Summary The effect of some common rhizosphere fungiviz Aspergillus niger, A. terreus, A. flavus, Fusarium nivale, Cunninghamella echinulata, Trichoderma viride andPaecilomyces fusisporus on the root growth of seedlings ofDichanthium annulatum andSetaria glauca was studied. The seedlings grown in modified Crone's nutrient medium were inoculated with the test fungi. In uninoculated control tubes, seedlings showed normal root growth. The different fungi exceptF. nivale were found to reduce root growth considerably. WithA. niger besides reduction in root length, the leaves of the seedlings were found to turn yellow. The reduction in root growth in the presence of fungi was statistically significant.  相似文献   

4.
Physiological responses ofAchlya proliferoides, Saprolegnia ferax andDictyuchus sterilis as affected by the fungicide chlorothalonil (Bravo) were determined. Glucose consumption differed in dependence on the organisms used. Ammonia and peptide nitrogen secretion were stimulated inS. ferax but inhibited in the other two organisms. All doses of the fungicide used decreased phosphorus absorption and increased acid phosphatase activity. The lowest concentrations (30 ppm) of the fungicide increased DNA, RNA and protein synthesis while inhibition was observed at moderate or high concentrations. Aspartate aminotransferase and alanine aminotransferase activities were inhibited inA. proliferoides, stimulated inS. ferax but remained similar to that of the control inD. sterilis.  相似文献   

5.
 We describe the effects of trehalose on spawn storage in a home freezer (average temperature, −16°C) where edible fungi usually do not survive. When the mycelia of Lentinula edodes were stored in a freezer for 3 days, the survival rate of mycelia cultivated on 2% glucose medium was 30%, whereas those on media containing 2% and 5% trehalose were 50% and 60%, respectively. Addition of trehalose to the culture was more effective in Pleurotus ostreatus. These results suggest that trehalose played the role of a stress protectant against freezing, because the mycelia cultured on a trehalose medium grew more rapidly and produced more fruiting bodies compared to those cultured on glucose. Received: February 6, 2002 / Accepted: October 1, 2002 Acknowledgments This work was partially supported by a Grant in Aid for Scientific Research (c) (2) No. 12660156 from the Japan Society for the Promotion of Science. We also gratefully acknowledge a grant from Hokuto Foundation for the Promotion of Biological Science. Correspondence to:T. Terashita  相似文献   

6.
Six isolates of ectomycorrhizal fungi namely, Laccaria fraterna (EM-1083), Pisolithus tinctorius (EM-1081), Pisolithus tinctorius (EM-1290), Pisolithus tinctorius (EM-1293), Scleroderma verucosum (EM-1283), and Scleroderma cepa (EM-1233), were grown on three variants of coal ash, namely electrostatically precipitated (ESP) ash, pond ash, and bottom ash moistened with Modified Melin-Norkans (MMN) medium in vitro The colony diameter reflected the growth of the isolates on the coal ash. Metal accumulation in the mycelia was assayed by atomic absorption spectrophotometry. Six metals, namely aluminum, cadmium, chromium, iron, lead, and nickel, were selected on the basis of their abundance in coal ash and toxicity potential for the present work. Growth of vegetative mycelium on fly ash variants and metal accumulation data indicated that Pisolithus tinctorius (EM-1290) was the most tolerant among the isolates tested for most of the metals. Since this isolate is known to be mycorrhizal with Eucalyptus, it could be used for the reclamation of coal ash over burdened sites.  相似文献   

7.
We studied the fungicidal activity of a biological preparation from the fungi of the genus Chaetomium against soil phytopathogenic fungi Rhizoctonia solani and Fusarium oxysporum. The inhibitory effect of the preparation under study depended on its concentration, duration of storage, and growth characteristics of pure cultures of the phytopathogens. The highest (98.8%) inhibitory activity was observed on day 3 of the interaction with Rhizoctonia solani. After a 2-year storage, this preparation was capable of inhibiting the growth of the phytopathogens only at high doses. The preparation precluded the development of bare patch and increased the productivity of potato plants. The preparation may serve as an alternative to chemical fungicides for plant protection.  相似文献   

8.
Abstract:  The aim of this study was to test the hypothesis that the whitefly ( Bemisia tabaci ; Hom., Aleyrodidae) predator ladybird beetles, Delphastus catalinae (Col., Coccinellidae), are not adversely affected in the field by the crude insecticidal toxins extracted from two strains of the fungus Verticillium lecanii , V3450 and Vp28. We developed a method to evaluate sublethal toxicity and its effects on consumption and functional response of D. catalinae . The crude toxins have low toxicity against beetle larva with LC50 values of 1942 (1393–2710) and 2471 (1291–4731) p.p.m., respectively (approximately 10- and 12-fold of field rate of application 200 p.p.m.). The adult beetles had less sensitivity to crude toxins with LC50 values of 4260 (3376–5375) and 4426 (1734–11298) p.p.m., respectively (approximately 20- and 22-fold of field rate 200 p.p.m.). The consumption and foraging capacity were significantly impaired especially in the second-instar larval beetles which took longer time (more than twice of the control beetles) to consume whitefly eggs after exposure to toxins, although D. catalinae suffered no significant effect on fecundity and longevity, when exposed to a toxin dilution of field rate. The data suggest that spraying of V. lecanii or its toxins should be avoided in the field having immature stages of D. catalinae .  相似文献   

9.
Increasing the pH from 5 to 9 decreased the toxicity of mercuric chloride, zinc sulfate, lead nitrate, copper sulfate and nickel chloride toward the growth ofAspergillus flavus, Penicillium chrysogenum, Cunninghamella echinulata, Myrothecium verrucaria andPhoma humicola. On the other hand, the toxicity of cadmium chloride was increased by the increasing pH. Also increasing the concentration of organic matter (peptone and yeast extract) from 0.5 to 1.5% induced a significant reduction in the toxicity of all heavy metals toward the growth of all test fungi.  相似文献   

10.
11.
Methanol and ethanol extracts of mansonia wood inhibited the growth of three wood-rotting fungi, Pleurotus ostreatus, Gloeophyllum sepiarium and Gloeophyllum sp. An aqueous extract only inhibited the growth of P. ostreatus. Extracted obeche wood impregnated with ethanol extracts of mansonia showed significant improvement in decay resistance. Impregnation with methanol extracts only significantly retarded decay by P. ostreatus and the aqueous extracts did not increase obeche wood resistance to any of the test fungi.  相似文献   

12.
T. I. Ofuya 《BioControl》1997,42(1-2):277-282
This study was conducted to examine the effects of some aphicidal biologically active plant compounds on the natural enemies of the cowpea aphid,Aphis craccivora Koch. In the laboratory, acetone extracts ofCymbopogon citratus (DC) Stapf.,Momordica charantia L.,Zingiber officinale Rose andAframomum melegueta (Rose) K. Schum, were tested for toxicity to two coccinellid species,Cheilomenes lunata (Fabricius) andCheilomenes vicina (Mulsant) predaceous on the aphid. All the extracts were highly ovicidal to eggs of the two coccinellid predators. None of the extracts caused mortality of eitherC. lunata orC. vicina fourth-instar larvae after 24 h. Larvae treated with the extracts consumed fewer aphids in 24 h than untreated larvae. Ability to pupate was also significantly reduced in larvae treated with the extracts. No morphological deformities were observed in adults emerging from treated larvae.  相似文献   

13.
Crude extracts from three green seaweeds (Cladophora dalmatica, Enteromorpha intestinalis, Ulva lactuca) and the three red algae (Corallina mediterranea, Jania rubens, Pterocladia pinnate) were prepared. Their effects on germination, growth of seedlings, chlorophyll content and other metabolic activities of Vicia faba were investigated. The crude extract of C. dalmatica showed maximal activity, and it increased seed germination, length of main root and shoot systems and the number of lateral roots. All the crude extracts of seaweed increased protein content in both root and shoot systems, total soluble sugars and chlorophyll content in leaves. The cytokinin content of the green algae was higher than that in red algae. Growth of seedlings of V. faba was stimulated but to different degrees.  相似文献   

14.
Experiments assessed the effect of four foliar essential oil phenotypes from a coastal redwood (Sequoia sempervirens) population on isolates of six fungus species with leaf endophytic stages. The hypothesis tested was that leaf essential oil phenotypes would have differential effects in vitro on these endophytic species. Another objective was to determine whether differences in response to redwood essential oils existed among pathogens isolated from redwood and a mutalistic endophtye never isolated from redwood. These species were: Botrytis cinerea, an opportunist generalist pathogen able to attack redwood; Pestalotiopsis funerea, Phomopsis occulta and Seiridium juniperi, actual or potential conifer pathogens isolated as leaf endophytes in redwood; Cryptosporiopsis abietna, a common conifer endophyte with uncertain ecological status isolated from redwood; and Meria parkeri, a mutalistic endophyte known only from Douglas fir. The four essential oil phenotypes were uniformly inhibitory for some species and differentially so for others. Susceptibility to the four phenotypes varied widely within and among fungus species. The conifer-specific pathogens were the least susceptible and the Douglas fir endophyte the most; the other two displayed intermediate susceptibility. The diversity of responses by these fungus species suggests that these redwood terpenoids may have a differential intra- and interspecific importance in preventing pathogenic activity in the species found within redwood foilage.  相似文献   

15.
3-(2-Pyridyl)-3-iminoisatin, 1-piperidinomethyl-3-(2-pyridyl)-3-iminoisatin, and 1-acetyl-3-(2-pyridyl)-3-iminoisatin affect spore germination ofAlternaria alternata, A. carthemi, Curvularia lunata, Fusarium oxysporum f.sp.cieri andF. udum and influence the development of powdery mildew (Erysiphe pisi) on pea under glasshouse condition as well as conidial germination ofE. pisi on excised pea leaves. Spore germination was inhibited in the sequence 1-acetyl-3-(2-pyridyl)-3-iminoisatin > 1-piperidinomethyl-3-(2-pyridyl)-3-iminoisatin > 3-(2-pyridyl)-3-iminoisatin followed the order accordingly. The powdery mildew development and conidial germination ofE. pisi 1-piperidinomethyl-3-(2-pyridyl)-3-iminoisatin > 1-acetyl-3-(2-pyridyl)-3-iminoisatin > 3-(2-pyridyl)-3-iminoisatin. The chemicals were compared with commonly used antifungal fungicides.  相似文献   

16.
In this paper, four fungi collected in Nansei Islands are reported. One is Strasseria garciniae, which must be transferred to the genus Phyllosticta. This fungus was collected in Okinawa Main Island and Iriomote Island. The other three fungi are newly added to the Japanese fungal flora. Phyllosticta ghaesembillae on Codiaeum variegatum and Cercospora asplenii on Asplenium antiquum were collected in Yoron Island. The last one, Coniella australiensis on Eucalyptus robusta was collected in Okinawa Main Island. Their morphology and symptoms on the host plant are described, with some mycological notes.  相似文献   

17.
Eleven fungal isolates and their secondary metabolites incorporated into artificial diet were tested for oral toxicity to the tobacco budworm (TBW) by examining larval weight, efficiency of conversion of ingested food to body tissue (ECI), pupal weight, days to pupation, and mortality. Two isolates of Altemaria alternata, two isolates of Fusarium moniliforme, three isolates of F. oxysporum and an isolated of F. solani reduced larval weight 90–99% after 7 days and inhibited pupation. ECI was reduced 34–96% in control groups. One isolate of A. alternata reduced pupal weight by 67% and increased the time to pupation three‐fold. One isolate of Cladosporium cladosporioides reduced larval weights by 56% and pupal weights by 7%. In a preference test of these isolates incorporated at a 1:4 ratio into artificial diet, 48% of the larvae were found on diet cubes containing autoclaved rice, 19% on standard diet, 10% on C. cladosporioides, 6–9% on F. solani, 8% on A. alternata and 3% on F. moniliforme. The fusarial toxins, T‐2 and diacetoxyscirpenol (DAS), were the most active compounds against TBW larvae among the 10 microbial toxins tested. T‐2 toxin reduced larval weight by 87%, reduced ECI by 62%, reduced pupal weight by 33% and delayed pupation by 1 week DAS caused similar but less severe effects than T‐2 toxin. AAL‐toxin inhibited larval growth and reduced pupal weights by 20% and 13%, respectively. A. alternata, F. moniliforme and F. solani were also phytotoxic to alfalfa (Medicago sativa,), crimson clover (Trifolium incarnatum) and wild geranium (Geranium dissectum,), which are early season plant hosts of TBW.  相似文献   

18.
The growth rate of abalone post larvae of Haliotis rufescens fed ad libitum with a benthic monoalgal diatom culture maintained as monocultures on a semi-commercial scale, was evaluated and correlated with the biochemical composition of the diatoms. The cell size (7.0 × 4.0 μm to 21.0 × 7.5 μm), protein percentage (7.42% to 13.66%), and ash content (49.03% to 59.61%) were different among diatom strains; lipid percentage, nitrogen free extract, and energy content (Kcal g−1) were similar among diatom strains. The values of essential and non-essential amino and fatty acids composition differed among diatom strains. Differences in the abalone shell length and orthogonal analyses revealed postlarval growth was dependent on the quality of the food source. Postlarvae abalone displaying the longest shell lengths were fed Nitzschia thermalis var. minor and Amphiprora paludosa var. hyalina (1,712.0 ± 61 μm and 1,709 ± 67 μm, respectively), followed by Navicula incerta (1,413.3 ± 43 μm). The fatty acid content of benthic diatoms and abalone growth rate were not correlated.  相似文献   

19.
Juvenile (3.0 ± 0.2 g) gibel carp (Carassius auratus gibelio) were fed to satiation for 8 weeks to investigate the effect of feeding frequency on growth, feed utilization and size variation. Five feeding frequencies were tested: two meals per day (M2), three meals per day (M3), four meals per day (M4), 12 meals per day (M12) and 24 meals per day (M24). The results showed that daily food intake increased significantly with the increase in feeding frequency and there was no significant difference between daily food intakes in M12 and M24 treatments. Growth rate, feed efficiency increased significantly with increasing feeding frequencies. Size variation was not affected by feeding frequency. Apparent digestibility of dry matter was not influenced by feeding frequency, while apparent digestibility of protein and energy increased significantly at high feeding frequencies. The feeding frequency had no significant effect on the moisture, lipid, protein, or energy contents of gibel carp, while the ash content decreased with increased feeding frequency. It was recommended that 24 meals per day was the optimal feeding frequency for juvenile gibel carp.  相似文献   

20.
M A Calvo  M Agut  R M Calvo  J Larrondo 《Microbios》1999,98(391):179-187
The ability of strains of the Arthrinium genus to inhibit microbial development has been previously described. In the present work different periods of mutagenic treatment using ultraviolet light, and of nitrosoguanidine treatment, on strains of Arthrinium were investigated. With nitrosoguanidine treatment the survival rate ranged from 2.17 to 8.78%. Mutant strains were only obtained with a higher antibiotic production in comparison with the wild-strain, when the mutagenic agent was UV light.  相似文献   

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