Effect of the raw extract of Arthrinium strains (Hyphomycetes, Dematiaceae) on the growth of pathogenic bacteria in poultry feed

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.     

Antifungal activity of some plant extracts on some pathogenic fungi

The inhibitory activity of five plant extracts viz. Artemisia absinthium L., Rumex obtusifolius L., Taraxacum officinale Weber ex Wiggers, Plantago lanceolata L. and Malva sylvestris L. were evaluated against the mycelial growth of three fungi Alternaria alternata (Fr.) Keissler, Penicillium expansum Link ex Thom. and Mucor piriformis Fisher that cause rot diseases in fruits and vegetables resulting in low yield and quality of fruits and vegetables. Results revealed that all the concentrations of plant extracts brought about significant inhibition in the mycelial growth of these pathogenic fungi. However, the highest concentration caused maximum inhibition in the mycelial growth followed by lower concentrations of plant extracts. The extract of A. absinthium leaves at highest concentration (S) proved highly effective in inhibiting the mycelial growth of all these pathogenic fungi followed by other plant extracts. These plants thus may have potential as the new natural fungicide for management of fungal rot diseases.     

Effect of pea and soybean extracts on the growth of five clostridium strains

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.     

Effect of some common rhizosphere fungi on root growth of seedlings

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.     

Effect of the fungicide chlorothalonil (Bravo) on some metabolic activities of aquatic fungi

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.     

Effect of trehalose on the spawn storage in some edible mushroom fungi (2): Effect on preservation in the freezer

 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     

Effect of static magnetic field on growth and sporulation of some plant pathogenic fungi

Growth and sporulation of phytopathogenic microscopic fungi were studied under a static magnetic field. The applied flux densities were 0.1, 0.5, and 1 mT. The magnetic field decreased the growth of colonies by 10% using this flux density region. At 0.1 mT flux density, the deviations are significant, P =.001, while in other cases the deviations generally are not significant. At the same time, the number of the developed conidia of Alternaria alternata and Curvularia inaequalis increased by 68-133%, but the number of Fusarium oxysporum conidia decreased by 79-83%. The deviations are generally significant at the P =.05 level.     

Effect of temperature on growth of some avirulent fungi and cross-protection against the wheat take-all fungus

The linear growth rates of Gaeumannomyces graminis var. graminis, G. graminis var. tritici, Phialophora radicicola var. graminicola and a lobed hyphopodiate Phialophora sp. were studied on agar at various temperatures between 5 and 30 °C and on wheat roots at two temperature regimes (12 h at 7°/12 h at 13 °C and 12 h at 17°/12 h at 23 °C). On agar at 30 °C, the isolates of G. graminis graminis grew faster than those of G. graminis tritici and Phialophora sp. but three isolates of G. g. graminis grew more slowly than the other two fungi at 5 and 10 °C. Two other isolates of G. g. graminis were cold-tolerant and had growth rates comparable to those of G. g. tritici and Phialophora sp. at 10 °C. The growth rates of Australian isolates of P. radicicola graminicolu were similar to that of a British isolate and were about a third to a half those of the other three fungi at most temperatures. The growth rates of the fungi on wheat roots at the low and high temperature regimes were correlated with the growth rates on agar at 10 and 20 °C respectively. The correlation was better at low temperatures r= 0.81) than at high temperatures (r = 0.62). Cross-protection experiments using two G. g. graminis isolates which grow poorly at temperatures below 15 °C and a cold-tolerant isolate each of G. g. graminis and Phialophora sp. showed that, while all four fungi protected wheat against take-all at high temperatures (17/23 °C) as evidenced by less severe disease and significantly greater dry weights, only the cold-tolerant fungi were effective at low temperatures (7/13 °C). The use of cold-tolerant isolates of avirulent fungi in field experiments may result in better protection in the early stages of wheat growth when Australian soil temperatures are mostly below 15 °C.     

Effects of toxins from two strains of Verticillium lecanii (Hyphomycetes) on bioattributes of a predatory ladybeetle, Delphastus catalinae (Col., Coccinellidae)

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 .     

Effect of coal ash on growth and metal uptake by some selected ectomycorrhizal fungi in vitro

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.     

Effect of pH and organic matter on the toxicity of heavy metals to growth of some fungi

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.     

Effect of a preparation from Chaetomium fungi on the growth of phytopathogenic fungi

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.     

Effect of crude mansonia (Mansonia altisima) timber extracts on biodeterioration of obeche (Triplochiton scleroxylon) timber by three wood-rotting fungi

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.     

Effect of group size on feed intake, growth and feed efficiency of juvenile perch

Feed intake, growth and feed efficiency of juvenile perch Perca fluviatilis were significantly affected by group size, with fish in groups of 12 having lower feed intake, higher growth and higher feed efficiency than solitary individuals. The same trend was seen for fish in groups of 12 compared to fish in groups of four, and for fish in groups of four compared to solitary individuals, although the differences were not always significant. The high growth and low feed efficiency for fish in groups may be caused by benefits obtained from shoaling such as reduced levels of stress.     

Effect of some plant extracts on two coccinellid predators of the cowpea aphid,Aphis craccivora (Hom.: Aphididae)

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.     

Notes on some plant-inhabiting fungi collected from the Nansei Islands (1)

In the course of a survey on plant diseases and their pathogenic fungi in the Nansei Islands, some noteworthy fungi were collected. Among them, four fungi newly found in Japan were described with some mycological and pathological notes. These species are Septoria gardeniae Savelli, causing circular leaf spot of Gardenia; Phyllosticta cordylinophila Young apud Stevens, causing brown leaf spot of Cordyline; Phyllosticta drummondii Vanef et van der Aa, causing brown needle blight of Araucaria; and Phyllachora minuta Hennings, causing tar spot of Hibiscus.     

Notes on some plant-inhabiting fungi collected from the Nansei Islands (2)

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.     

Effect of some leaf essential oil phenotypes in coastal redwood on the growth of several fungi with endophytic stages

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.