Effects of various soil fungi and insecticides on the capacity of Mucor alternans to degrade DDT

1972 ◽  
Vol 18 (5) ◽  
pp. 553-560 ◽  
Author(s):  
J. P. E. Anderson ◽  
E. P. Lichtenstein

Pure cultures of the fungus Mucor alternans, isolated from DDT-contaminated soils, were able to degrade DDT to water-soluble metabolites. After the addition of fungal spores to DDT-contaminated soils, however, the insecticide-degrading capacity of the fungus was no longer evident. Since under field conditions many species of fungi are simultaneously exposed to mixed residues of pesticidal chemicals, the effects of various species of soil fungi and of various insecticides on DDT degradation by M. alternans were investigated. Experiments were conducted to study the effect of nine fungal species, their stale cell-free media, and various insecticides and related compounds on the capacity of M. alternans to degrade 14C-DDT to water-soluble metabolites. It was found that several pure fungal cultures or some cell-free media, in which mycelia had grown, could also degrade the insecticide. In most cases, however, addition of one of the various fungi to 14C-DDT-treated M. alternans cultures resulted in a total depression of the appearance of water-soluble metabolites in the media. This was due to an accumulation of the metabolites in the mycelium of the other fungus or in an inhibition of metabolite formation. Addition of stale media from various fungi to 14C-DDT-treated M. alternans cultures had various effects on fungal growth and on the capacity of the fungus to degrade the insecticide. Among the insecticides and related compounds tested only lindane, parathion, and Dyfonate caused a reduction in DDT degradation by M. alternans, without severely reducing its vegetative growth.

1935 ◽  
Vol 6 (2) ◽  
pp. 154-167 ◽  
Author(s):  
T. R. Vernon

1. Six types of surface discolorations are described and a list is given of the fungi causing these discolorations. The fungi listed are shown to be capable of reproducing the discolorations under experimental conditions.2. The surface moulding of butter is shown to depend largely on the weather conditions at the time of removal from cold store (temperature and humidity), and the foodstuffs available from the wrapping materials.3. The butter, boxwood and parchment are capable, in the presence of free water, of supplying substances which stimulate the germination of fungal spores.4. The water-soluble extract of parchment stimulates fungal germination and growth. Its value as a nutrient is masked when parchment is in contact with butter. Even a well-washed parchment is capable of supporting fungal growth.5. The butter and the boxwood are even more important as sources of soluble food material than parchment of high “water-soluble” content.6. Glycerine is a source of food for fungi and a glycerine-softened parchment is more liable to mould attack than a glycerine-free paper.7. It has been shown that the softening of parchment with salt does not prevent mould attack. Two strains of Cladosporium herbarum and Penicillium sp. attacked salt-softened parchment more easily than untreated parchments.


2008 ◽  
Vol 1 (1) ◽  
pp. 26-34 ◽  
Author(s):  
Y. Iossifova ◽  
T. Reponen ◽  
M. Daines ◽  
Linda Levin ◽  
G.K. Khurana Hershey

There are two methods available for the analysis of (1-3)-β-D-glucan: the Limulus Amebocyte Lysate assay (LAL) and the inhibition Enzyme Immunoassay (EIA). The aim of this study was to compare the accuracy and specificity of these two methods in detecting eight alpha and beta-glucan standards, and their sensitivity for the analysis of (1-3)-β- D-glucan content of common indoor fungal species and indoor dust samples. The results show that the LAL assay is more accurate, specific, and sensitive in measuring linear and branched β-D-glucans than the EIA. The greatest LAL-analyzed (1-3)-β-D-glucan content per spore (241 pg/spore) was found with E. nigrum, which also had the largest spore size (28 μm). The biomass-normalized (1-3)-β-D-glucan content of fungal spores from pure cultures was within similar range with the two assays but no correlation was found between the results from the two assays. In contrast, there was a significant correlation between the EIA and LAL-measured (1-3)-β-D-glucan concentrations (μg/m2 of floor area) in field dust samples.


2016 ◽  
Vol 27 (2) ◽  
pp. 263-269 ◽  
Author(s):  
Iwona Beech ◽  
Anna Otlewska ◽  
Justyna Skóra ◽  
Beata Gutarowska ◽  
Christine Gaylarde

Field emission scanning electron microscopy coupled with energy dispersive X-ray spectroscopy analysis of white-painted gypsum panels incubated for 11 months with either a consortium comprising several fungal species or their monocultures demonstrated that spores of Penicillium minioluteum concentrated titanium, a common white paint ingredient. The paint coating was severely degraded and the exposed underlying gypsum seen was to be contaminated with fungal spores. Ulocladium atrum, while growing well on consortium-inoculated panels over 12 weeks, failed to remain the principal colonizer after 11 months and did not concentrate minerals on its spores nor show visible degradation of the coating. When inoculated in pure culture, U. atrum failed to thrive on the panels, its concentration, measured as ergosterol, falling after 21 days. U. atrum, previously reported to be the major surviving fungus after the 12-week incubation based on the British Standard test BS3900 for fungal growth on paint, has discolouring but not degrading effects and probably grows on the paint coating at the expense of organic matter, including that originating from other fungal species. Ulocladium consortiale, a strain that grew on stored uninoculated panels, caused paint coating degradation visible under field emission scanning electron microscopy and detected as reduction in titanium in the underlying paint coating; however, it did not concentrate any particular elements on its spores.


1997 ◽  
Vol 77 (1) ◽  
pp. 95-103 ◽  
Author(s):  
M. Undi ◽  
K. M. Wittenberg ◽  
N. J. Holliday

A study was conducted to evaluate the effect of moisture content at baling on fungal growth during storage of alfalfa forage. Alfalfa forage was baled at DM contents of 64.1–66.2% (Low), 71.9–73.2% (Medium) and 75.4–77.4% (High) and was sampled 1, 2, 3, 4, 5, 6, 7, 8, 9, 14, 21, 35 and 60 d after storage. For each sample, abundance of fungal and yeast species was assessed by plating on media. Total fungal counts, number of species, species diversity, and species dominance were subjected to analysis of variance, and variation in the fungal assemblages was characterized by ordination. Total fungal counts, number of species, species diversity, and species dominance were not influenced (P > 0.05) by moisture content in the early (days 1 to 8) storage phase. Moisture content at baling did influence (P < 0.05) total counts, number of species, and species dominance in the latter phase (days 9 to 60) of storage. Total fungal counts were highest in Low DM forage, and number of species highest in Medium DM forage. Species dominance was highest in High DM forage. Low DM forage was associated with Aspergillus fumigatus, Mucor spp., Absidia spp., Emericella nidulans, and thermotolerant hyphomycetes. Aspergillus repens, Absidia spp. and some yeasts were more predominant in Medium and High DM forages. Moisture content and temperature were related to species assemblages during storage but water-soluble carbohydrate concentration, crude protein concentration and total bacteria counts were not. "Field" fungi, Phoma, Alternaria, Cladosporium spp. and most yeasts were eliminated within 8 d of storage. Physical conditions created in the early stages of storage likely affected fungal growth in the later storage phase. Key words: Moisture content, temperature, storage, alfalfa hay, fungal species, diversity


1974 ◽  
Vol 20 (3) ◽  
pp. 399-411 ◽  
Author(s):  
S. J. Flashinski ◽  
E. P. Lichtenstein

The metabolism and detoxication of 14C-(ethoxy) and 14C-(ring)-Dyfonate were demonstrated with isolated soil fungi. Quantitative and qualitative differences in the production of insecticide metabolites were observed. Among the nine fungal species tested, Mucor plumbeus and Rhizopus arrhizus were most active in degrading the insecticide, while Penicillium notatum was the least active. This activity was evidenced by the production of increasing amounts of water-soluble 14C-compounds in the culture media and the disappearance (degradation) of the originally applied insecticide from the fungal cultures. The water-soluble metabolites were non-toxic to mosquito larvae. Hexane-extractable compounds from cultures of the most active species were non-toxic to fruit flies, while those from cultures of the less active fungal species were insecticidal. Among the metabolites produced and detected by thin-layer chromatography were primarily dyfoxon, ethylethoxyphosphonothioic acid, ethylethoxyphosphonic acid, methyl phenyl sulfoxide, and methyl phenyl sulfone. With Aspergillus niger and 14C-(ring)-Dyfonate, most of the radiocarbon recovered from the TLC-plates was associated with an unknown compound. Production of the metabolites by the fungi was a function of the live mycelia, followed by excretion of water-soluble 14C-compounds into the culture media.


Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Jing Wang ◽  
Chaoyun Xu ◽  
Qiming Sun ◽  
Jinrong Xu ◽  
Yunrong Chai ◽  
...  

Abstract Background Microbiome interactions are important determinants for ecosystem functioning, stability, and health. In previous studies, it was often observed that bacteria suppress potentially pathogenic fungal species that are part of the same plant microbiota; however, the underlying microbe-microbe interplay remains mostly elusive. Here, we explored antagonistic interactions of the fungus Fusarium graminearum and bacterium Streptomyces hygroscopicus at the molecular level. Both are ubiquitous members of the healthy wheat microbiota; under dysbiosis, the fungus causes devastating diseases. Results In co-cultures, we found that Streptomyces alters the fungal acetylome leading to substantial induction of fungal autophagy. The bacterium secrets rapamycin to inactivate the target of rapamycin (TOR), which subsequently promotes the degradation of the fungal histone acetyltransferase Gcn5 through the 26S proteasome. Gcn5 negatively regulates fungal autophagy by acetylating the autophagy-related protein Atg8 at the lysine site K13 and blocking cellular relocalization of Atg8. Thus, degradation of Gcn5 triggered by rapamycin was found to reduce Atg8 acetylation, resulting in autophagy induction in F. graminearum. Conclusions Autophagy homeostasis plays an essential role in fungal growth and competition, as well as for virulence. Our work reveals a novel post-translational regulation of autophagy initiated by a bacterial antibiotic. Rapamycin was shown to be a powerful modulator of bacteria–fungi interactions with potential importance in explaining microbial homeostasis in healthy plant microbiomes. The autophagic process provides novel possibilities and targets to biologically control pathogens.


Biology ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 497
Author(s):  
Rafał Ogórek ◽  
Mateusz Speruda ◽  
Justyna Borzęcka ◽  
Agata Piecuch ◽  
Magdalena Cal

Most underground ecosystems are heterotrophic, fungi in these objects are dispersed in the air in the form of spores, and they may be potentially hazardous to mammals. Research in underground sites has focused on mesophilic airborne fungi and only a few concerned cold-adapted species. Therefore, the goal of our research was the first report of psychrophilic and psychrotolerant aeromycota in the Brestovská Cave using culture-based techniques with genetic and phenotypic identification. Plates with PDA medium containing sampled biological material were incubated at 8 ± 0.5 °C. The density of mycobiota inside the cave ranged from 37.4 to 71 CFU 1 m−3 of air and 63.3 CFU 1 m−3 of air outside the cave. Thus, the level of fungal spores did not exceed the standards for the mycological quality of the air. A total of 18 species were isolated during the study, and some species may be potentially dangerous to people with weakened immune system. All fungal species were present inside the cave and only seven of them were outside. Cladosporium cladosporioides dominated in the external air samples and Mortierella parvispora was cultured most frequently from internal air samples. To our knowledge, this is the first discovery of the fungal species such as Coniothyrium pyrinum, Cystobasidium laryngis, Filobasidium wieringae, Leucosporidium drummii, M. parvispora, Mrakia blollopis, Nakazawaea holstii, and Vishniacozyma victoriae in the air inside the underground sites. Moreover, C. pyrinum, C. laryngis, L. drummii, M. blollopis, and N. holstii have never been detected in any component of the underground ecosystems. There are possible reasons explaining the detection of those species, but global warming is the most likely.


Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1489
Author(s):  
Tammy Stackhouse ◽  
Sumyya Waliullah ◽  
Alfredo D. Martinez-Espinoza ◽  
Bochra Bahri ◽  
Emran Ali

Dollar spot is one of the most destructive diseases in turfgrass. The causal agents belong to the genus Clarireedia, which are known for causing necrotic, sunken spots in turfgrass that coalesce into large damaged areas. In low tolerance settings like turfgrass, it is of vital importance to rapidly detect and identify the pathogens. There are a few methods available to identify the genus Clarireedia, but none of those are rapid enough and characterize down to the species level. This study produced a co-dominant cleaved amplified polymorphic sequences (CAPS) test that differentiates between C. jacksonii and C. monteithiana, the two species that cause dollar spot disease within the United States. The calmodulin gene (CaM) was targeted to generate Clarireedia spp. specific PCR primers. The CAPS assay was optimized and tested for specificity and sensitivity using DNA extracted from pure cultures of two Clarireedia spp. and other closely related fungal species. The results showed that the newly developed primer set could amplify both species and was highly sensitive as it detected DNA concentrations as low as 0.005 ng/µL. The assay was further validated using direct PCR to speed up the diagnosis process. This drastically reduces the time needed to identify the dollar spot pathogens. The resulting assay could be used throughout turfgrass settings for a rapid and precise identification method in the US.


2020 ◽  
Vol 21 (22) ◽  
pp. 8681
Author(s):  
Nicolò Orsoni ◽  
Francesca Degola ◽  
Luca Nerva ◽  
Franco Bisceglie ◽  
Giorgio Spadola ◽  
...  

As key players in biotic stress response of plants, jasmonic acid (JA) and its derivatives cover a specific and prominent role in pathogens-mediated signaling and hence are promising candidates for a sustainable management of phytopathogenic fungi. Recently, JA directed antimicrobial effects on plant pathogens has been suggested, supporting the theory of oxylipins as double gamers in plant-pathogen interaction. Based on these premises, six derivatives (dihydrojasmone and cis-jasmone, two thiosemicarbazonic derivatives and their corresponding complexes with copper) have been evaluated against 13 fungal species affecting various economically important herbaceous and woody crops, such as cereals, grapes and horticultural crops: Phaeoacremonium minimum, Neofusicoccum parvum, Phaeomoniella chlamydospora, Fomitiporia mediterranea, Fusarium poae, F. culmorum, F. graminearum, F. oxysporum f. sp. lactucae,F. sporotrichioides, Aspergillus flavus, Rhizoctonia solani,Sclerotinia spp. and Verticillium dahliae. The biological activity of these compounds was assessed in terms of growth inhibition and, for the two mycotoxigenic species A. flavus and F. sporotrichioides, also in terms of toxin containment. As expected, the inhibitory effect of molecules greatly varied amongst both genera and species; cis-jasmone thiosemicarbazone in particular has shown the wider range of effectiveness. However, our results show that thiosemicarbazones derivatives are more effective than the parent ketones in limiting fungal growth and mycotoxins production, supporting possible applications for the control of pathogenic fungi.


Forests ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 467 ◽  
Author(s):  
Ana Brglez ◽  
Barbara Piškur ◽  
Nikica Ogris

Eutypella parasitica R.W. Davidson and R.C. Lorenz is the causative agent of Eutypella canker of maple, a destructive disease of maples in Europe and North America. The fungus E. parasitica infects the trunk through a branch stub or bark wound. Because the fungal community may have an impact on infection and colonization by E. parasitica, the composition of fungi colonizing wood of dead branches of sycamore maple (Acer pseudoplatanus L.) was investigated in five sampling sites in Slovenia. Forty samples from each sampling site were collected between the November 2017 and March 2018 period. Isolations were made from the wood in the outer part of dead branches and from discoloured wood in the trunk that originated from a dead branch. Pure cultures were divided into morphotypes, and one representative culture per morphotype was selected for further molecular identification. From a total of 2700 cultured subsamples, 1744 fungal cultures were obtained, which were grouped into 212 morphotypes. The investigated samples were colonized by a broad spectrum of fungi. The most frequently isolated species were Eutypa maura (Fr.) Sacc., Eutypa sp. Tul. and C. Tul., Fusarium avenaceum (Fr.) Sacc., Neocucurbitaria acerina Wanas., Camporesi, E.B.G. Jones and K.D. Hyde and E. parasitica. In this study, we distinguished species diversity and the fungal community. There were no significant differences in the diversity of fungal species between the five sampling sites, and branch thickness did not prove to be a statistically significant factor in fungal species diversity. Nevertheless, relatively low Jaccard similarity index values suggested possible differences in the fungal communities from different sampling sites. This was confirmed by an analysis of similarities, which showed that the isolated fungal community distinctly differed between the five sampling sites and between the different isolation sources. Eutypella parasitica was isolated from all five investigated sampling sites, although Eutypella cankers were observed in only three sampling sites, indicating the possibility of asymptomatic infection.


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