Sulphur and phosphorus requirements of three fungi causing diseases in storage

Summary The effect of different sulphur and phosphorus compounds on the growth and reproduction of three fungi causing storage rot, viz.,Fusarium solani, Botryodiplodia ananassae andMacrophomina phaseoli has been studied. Sixteen different sources of sulphur were used and out of them magnesium sulphate was found to be most favourable for the growth and reproduction of all the three fungi. Sodium sulphite and sodium bisulphite were toxic. Potassium metabisulphite prevented growth ofF. solani and M. phaseoli while it supported moderate growth ofB. ananassae. Only magnesium sulphate could induce the sporulation ofB. ananassae while sporulation and sclerotial development ofF. solani andM. phaseoli respectively varied with the type of sulphur sources used. Optimum concentration of magnesium sulphate was also determined and it was found that the growth and sporulation ofF. solani andB. ananassae were best at 0.375 g/l and 0.75 g/l.M. phaseoli tolerated higher doses of this substance as the best growth and excellent sclerotial development were recorded at 3.0 g/l (the maximum concentration used). Phosphorus was found to be essential for the present fungi as none of them could grow in complete absence of this substance. Onthophosphates and nucleic acid, were found to be favourable sources for growth and reproduction of the 3 organisms.     

Production of extracellular plasmocoagulase in staphylococcus aureus exposed to 3,6-diaminoacridines]

A modified quantitative nephelometric method was used. It was shown that production of extracellular plasmocoagulase was depressed in the development of acridine-sensitive and acridine-resistant cultures of Staph. aureus in the fluid nutrient medium containing 3,6-diaminoacridines: acriflavine, proflavine, acridine yellow, acridine orange, acridine No. 40 and acridine No. 56; 3,6-diaminoacridines failed to lead to noncompetitive inhibition of staphylococcus plasmocoagulase. A disturbance of the regulation of the enzyme exit into the external environment can serve as the cause of depression of the extracellular plasmocoagulase production by Staph. aureus.     

Cyanuric acid as nitrogen source for micro-organisms

Summary Several fungi, among which species of Penicillium and Hormodendrum (?), were found to utilize cyanuric acid as a nitrogen source, assimilating 66 to 75% of its nitrogen in cell substance. The growth with cyanurate was essentially as good as with ammonia and urea nitrogen. The optimum reaction for growth was around pH 5 to 6, but pH 7 to 8 was suboptimal. No decrease in growth was seen at a cyanurate concentration of 9.3 mM. The triazine ring as such is thus not biologically very stable, and the strong persistance of the triazine herbicides simazine and atrazine must be ascribed to the external substituents and not to the central ring.     

A toxic substance produced by Nocardia otitidiscaviarum isolated from cutaneous nocardiosis

During our studies on toxic substances from clinically isolated Nocarida, a new isolate identified as Nocardia otitidiscaviarum from cutaneous nocardiosis was found to produce a toxic substance called HS-6 that had strong in vitro as well as in vivo toxicity. The mouse intraperitoneal LD₅₀ value was 1.25 mg/kg and the ED₅₀ value for L1210 cultured cells was 0.3 ng/ml. The structure of HS-6 was determined and found to belong to the 16-membered macrocyclic group with a molecular formula of C₄₃H₆₈O₁₂. HS-6 also showed activity against pathogenic fungi such as Cryptococcus neoformans.     

Antimicrobial agents

In the microbial degradation of Fungicidin by lower pathogenic fungi, no significant differences were found in the rate of its degradation by the various species of dermatophytes employed (Trichophyton mentagrophytes, Trichophyton rubrum andMicrosporum gypseum), but there was a marked difference in the rate of enzymatic degradation by microorganisms adapted and not adapted to Fungicidin or Amphotericin B. After four hours' degradation of Fungicidin by non-adapted strains, about 70% of the Fungicidin in the medium was still intact, whereas it was completely degraded by adapted strains during the same interval. The addition of protein biosynthesis inhibitors (chloramphenicol and tetracycline) and of the antifungally active substance 2-aminotridecane did not influence the microbial degradation of Fungicidin by dermatophytes.     

Medically important fungi found in hallux nails of university students from Cali, Colombia

The presence of medically important fungi was studied in hallux nails scrapings obtained from 504 students (204 males, 300 females) of three universities in Cali. Specimens were examined by direct microscopic examination and fungal culture. Medically important fungi were found in 49 (9.7%) students, 24 (4.8%) had onychomycosis while the rest did not have nail lesions. Trichophyton rubrum was the most commonly isolated fungi in students with lesions, where as T. mentagrophytes predominated in healthy nails. Most of the students with fungi were males. The prevalence of fungi was higher in individuals between 26 and 35 years. No association was observed between fungi and practicing sports or undergoing pedicures. These results suggest that dermatophytes can be found in healthy hallux nails, which can be reservoirs of pathogenic fungi.     

Characteristics of hospital strains of Staphylococcus]

Some properties of hospital staphylococcal strains isolated from the patients with purulent postnatal mastitis were studied. It was found that all the strains of the phage type 80.81 widely distributed in the obstetric hospitals were polylysogenic and polyresistant to antibiotics. The resistance markers in most of the isolates were located on the plasmids. Elimination of the plasmids carrying the antibiotics resistance markers resulted in a simultaneous change in the strain lysogenic spectrum while the phage type and fermentative properties, such as production of plasmocoagulase, DNAase and lecithinase did not change. The capacity for hemotoxin production was lost simultaneously with antibiotic resistance in 1 out of 17 cultures tested.     

Fungi associated with sorghum seeds

Summary A study of the external and internal fungi associated with different varieties ofSorghum seeds has been made. The varieties tested included eighteen local varieties and twelve newSorghum varieties obtained from the Rockefeller Foundation. The external fungi were studied by preparing suspensions of superficial fungi and growing on potato dextrose agar. The internal fungi were studied by planting surface sterilized seeds on P.D.A. and pure cultures of all these fungi were prepared.The external fungi found to be associated with the different varieties included different species ofPhycomyces, Circinella, Syncephalastrum, Chaetomium, Curvularia, Cladosporium, Helminthosporium, Montospora, Pullularia, Aspergillus, Penicillium, Cephalosporium, Trichoderma, Phoma, Fusarium.The internal fungi recovered from these varieties included species ofChaetomium, Cladosporium, Curvularia, Helminthosporium, Heterosporium, Hormodendron, Pullularia, Alternaria, Aspergillus, Blastomyces, Monilia, Penicillium, Fusarium, Phoma, Phomopsis. Varieties 4403B, 1060 and 503 were found to carry a large number of fungi. Variety Black spanish was found to be entirely free from any internal or external fungus. Varieties which were free from endophytic fungi but possess external fungi only were Kaoling 301, African variety 901 and Shallus 475. Three fungi viz.,Pullularia, Heterosporium, Monilia have been recovered from theSorghum seeds for the first time.     

Isolation and characterization of antifungal peptides produced by <Emphasis Type="Italic">Bacillus amyloliquefaciens</Emphasis> LBM5006

Bacillus amyloliquefaciens LBM 5006 produces antagonistic activity against pathogenic bacteria and phytopathogenic fungi, including Aspergillus spp., Fusarium spp., and Bipolaris sorokiniana. PCR analysis revealed the presence of ituD, but not sfp genes, coding for iturin and surfactin, respectively. The antimicrobial substance produced by this strain was isolated by ammonium sulfate precipitation, gel filtration chromatography and 1-butanol extraction. The ultraviolet spectrum was typical of a polypeptide and the infrared spectrum indicates the presence of peptide bonds and acyl group(s). The antimicrobial substance was resistant to proteolytic enzymes and heat treatment, and was reactive with ninhydrin. Mass spectroscopy analysis indicated that B. amyloliquefaciens LBM 5006 produces two antimicrobial peptides, with main peaks at m/z 1,058 Da and 1,464 Da, corresponding to iturin-like and fengycin-like peptides, respectively. B. amyloliquefaciens LBM 5006 showed significant activity against phytopatogenic fungi, showing potential for use as a biocontrol agent or production of antifungal preparations.     

Some Characteristics of Red Light-induced Substance(s) against Botrytis cinerea Produced in Broad Bean Leaflets

The red light-induced antifungal substance(s) produced in broad bean was of relatively high molecular weight, water soluble, heat stable and fungi specific. Cellulose thin layer chromatography (TLC) of infection droplets of Botrytis cinerea or water droplets without spores of B. cinerea, recovered from inoculated broad bean leaflets kept under red light for 48 h, displayed inhibition zones at approximate Rf values of 0.0 and 0.6. Inhibition zones observed in cellulose TLC of water droplets were relatively faint compared to those of infection droplets. In a time-course study of accumulation of the antifungal substance(s), antifungal activity in both water and infection droplets recovered from red light irradiated broad bean leaflets occurred after 24 h irradiation. However, the antifungal activity in infection droplets was significantly higher than in water droplets. The antifungal substance(s) was less active against Botrytis fabae than B. cinerea.     

Untersuchungen über endophytische Pilze der Rebe unter besonderer Berücksichtigung des Gefäßsystems der Unterlage

Investigations on endophytic fungi of grapevine with special emphasis on the vascular system of rootstocks In three vegetation periods endophytic fungi from rootstocks of grafted grapevines were isolated, and their influence on the host-plant was determined. Before grafting (pre-nursery) about 40 to 50% of grapevines were colonized by endophytic fungi; in grafted material after growing in a nursery this rate increased up to 50 to 90% (post-nursery). Most of these fungi are Deuteromycetes, especially Moniliales and Coelomycetes. Only a few Ascomycetes were found. The spectrumof fungi differs, mainly depending on the season (pre- and post-nursery), but less on the variety and year of sampling. Contradictory results from investigations of the relationship between the isolated fungi and the vitality of grafted grapevines were found, however the endophytes clearly showed no pathogenic character. On the contrary in some cases a higher vitality of the grapevines correlated with presence of endophytes.     

Release of a reducing substance by the ectomycorrhizal fungi Pisolithus tinctorius and Paxillus involutus

Culture solutions of the ectomycorrhizal fungi Pisolithus tinctorius and Paxillus involutus are shown to reduce a high valency oxide of manganese at a range of pH values from 3.0 to 13.0. Manganese reduction in unmoculated culture media was confined to pH values below 5.0 and above 10.0. The results are consistent with the release of a reducing substance from the fungal mycelium.     

Marine mycoflora of south India with special emphasis on lignicolous marine fungi

A study dealing with the marine fungi associated with decaying wood samples in the brackish water mangrove ecosystem and shoreline ecosystem was carried out in south India. A total of 19 marine fungi were isolated from the brackish water mangrove ecosystem. They included 13 Ascomycetes, one Basidiomycete and five Mitosporic fungi. In terms of percent frequency of occurrence, the most frequent species obtained from the brackishwater were the Lignincola longirostris (16.60%) and Savoryella lignicola (12.09%). Nine species were found frequently. Five species were occasionally encountered. Aigialus mangrovei, Aniptodera mangrovei and Halosarpheia marina were the rare species recorded. The average number of isolates per wood sample was 1.53. A total of 27 marine fungi including 15 ascomycetes, one basidiomycete and ten mitosporic fungi were recorded from the shoreline ecosystem. In terms of percent frequency of occurrence, the most frequent species obtained from Kanyakumari were the Arenariomyces trifurcates (13.66%), Corollospora maritima (12.44%), and Cirrenalia pygmea (10.98%). Seven species were found frequently. Fourteen species were occasionally encountered. Three species were found to be rare in occurrence. The average number of isolates per wood sample was 1.21.     

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.     

Vesicular-arbuscular mycorrhizal fungi,particularly Glomus tenue,in Venezuelan bromeliad epiphytes

The mycorrhizal status of water-impounding tank bromeliad epiphytes from three locales differing in altitude and moisture regime within Venezuelan cloud forest was examined. Species of vesicular-arbuscular mycorrhizal (VAM) fungi found in arboreal soils were compared to VAM fungi found in terrestrial soils. Sixteen of the 19 epiphytes examined for the presence of VAM fungi had roots with infection stages; 14 of these specimens showed growth of the fine endophyte Glomus tenue. Fine endophyte was the only VAM fungus found associated with epiphytes in the driest locale studied, while coarse VAM fungi (Gigaspora and Scutellospora spp.) were found at sampling locales receiving more moisture. Root infection was usually composed of intercellular hyphae and peletons; few arbuscules were observed. However, abundant extracellular hyphae were often observed tangled about roots in arboreal soil. It is concluded that epiphytic bromeliads probably benefit, at least periodically, from VAM fungi scavenging for sporadically available nutrients in arboreal soils. Glomus tenue may be particularly important as a colonizing VAM fungus in drier sites of Venezuelan cloud forest. The species composition of VAM fungi in arboreal soils was different to that of terrestrial soils sampled directly under epiphytic bromeliad perches, suggesting that VAM fungi species associated with bromeliads are dispersed to their hosts by vagile animal vectors.     

Spatial Ecology of the Fungal Genus Xylaria in a Tropical Cloud Forest

Fungal symbioses with plants are ubiquitous, ancient, and vital to both ecosystem function and plant health. However, benefits to fungal symbionts are not well explored, especially in non‐mycorrhizal fungi. The Foraging Ascomycete hypothesis proposes that some wood‐decomposing fungi may shift life‐history strategies to endophytism to bridge gaps in time and space between suitable substrates. To test this hypothesis we examine spatial relationships of Xylaria endophytic fungi in the forest canopy with Xylaria decomposer fungi on the forest floor. We sampled for fungi of the genus Xylaria using a spatially explicit sampling scheme in a remote Ecuadorian cloud forest, and concurrently carried out an extensive culture‐based sampling of fungal foliar endophytes. We found 36 species of Xylaria in our 0.5 ha plot, 31 of which were found to only occur as fruiting bodies. All five species of Xylaria found as endophytes were also found as fruiting bodies. We also tested the relationships of both stages of these fungi to environmental variables. Decomposer fungi were differentiated by species‐specific habitat preferences, with three species being found closer to water than expected by chance. In contrast, endophytes displayed no sensitivity to environmental conditions, such as host, moisture, or canopy cover. We found evidence of spatial linkage between life stages in two species. We also demonstrate that direct transmission of endophytes from leaves to woody substrates is possible. These results indicate that endophytism may represent one way for decomposer fungi to escape moisture limitation, and that endophytic fungi may act as sources of dispersal for decomposer fungi consistent with predictions of the Foraging Ascomycete hypothesis.     

Lipid of Streptomyces sioyaensis

Three ninhydrin-positive lipids of Streptomyces sioyaensis were found. These lipids were called substance A, B and C, tentatively. Study on the distribution of these lipids in Actinomycetales has shown that substance A was common in all of the strains tested, and that substance B was found in the limited strains. The substance C was characteristic only in Streptomyces sioyaensis.     

Influence of fungal plasmocoagulase on some microbial infections

The comparative investigation of plasmocoagulase and polysaccharide ofCandida albicans and staphylococcal coagulase shows that all substances inhibit the phagocytosis in vitro. These preparations suppress both the seizure of microbial cells by leucocytes and the digestion of phagocytosed microbes. In the experiments in vivo the substances partly inhibit phagocytosis when injected simultaneously with bacteria. When injected in advance, the preparations activated the phagocytosis.Plasmocoagulase and polysaccharide ofC. albicans when injected simultaneously with microbes complicate the infection independently of the etiologic agent.Investigation of plasmocoagulases and polysaccharides isolated from 25 species of fungi shows that most part of them complicates the infection under the simultaneous injection with bacteria. Preliminary injection revealed only extremely weak preventive action of some of them.The biologic activity of the plasmocoagulases and polysaccharides can be compared with that of microbial endotoxines.

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Zusammenfassung Die vergleichende Untersuchung von Plasmacoagulase und Polysaccharide vonCandida albicans und von staphylogener Coagulase zeigt, daß alle Substanzen die Phagozytose in vitro verhindern. Diese Substanzen unterdrücken sowohl das Einfangen der Bakterien durch die Leukozyten als auch die Verdauung der phagozitierten Bakterien. In den Experimenten in vivo unterdrücken die Substanzen teilweise die Phagozytose, wenn sie gleichzeitig mit den Bakterien injiziert werden. Wenn sie aber vorher injiziert werden, aktivieren die Preparate die Phagozytose. Wenn Plasmocoagulase und Polysaccharide vonC. albicans gleichzeitig mit den Bakterien injiziert werden, komplizieren sie die Infektion, unabhängig vom bakteriologischen Erreger. Untersuchungen von Plasmocoagulasen und Polysacchariden, gewonnen von 25 Arten von Fungi, zeigen, daß sie die Infektion meisten Teils komplizieren unter gleichzeitiger Injektion von Bakterien. Vorherige Injektion zeigte nur eine sehr schwache schützende Wirkung von einigen von ihnen. Die biologische Wirkung von Plasmacoagulasen und Polysacchariden kann mit der Wirkung der bakteriellen Endotoxinen verglichen werden.

     

Biodiversity and distribution of fungi associated with decomposing Nypa fruticans

Fungi associated with the decomposition of Nypa fruticans in Malaysia are under investigation. Forty-one fungi have been identified including 35 ascomycetes, four mitosporic fungi and two basidiomycetes. The distribution of intertidal fungi on palm structures including leaves, leaf veins, rachides, petiole bases, and inflorescences, and fungi on terrestrial parts have also been examined. No fungi were found on the leaf material, although several fungi were found on the leaf midribs, and possible reasons for this are given. Very few taxa developed on the inflorescences, but those that were present were abundant. The greatest density of fruiting structures occurred on the rachides, and the greatest diversity of fungal species occurred on the petiole bases. The terrestrial fungi differed from the intertidal fungi, although Linocarpon nipae occurred in both habitats. Reasons for the differences in fungal numbers and diversity on the various palm parts are discussed. The diversity of fungi at Morib mangrove was low when compared to previous studies on fungi on Nypa palm at Kampong Api Api in Brunei and in this study at Kuala Selangor mangrove in Malaysia.