Water activity-temperature relationships are reported for Yukon soil-isolated strains of Mortierella alpina and Penicillium expansum that are natural enemies to larvae(infestation stage)of the winter tick Dermacentor ...Water activity-temperature relationships are reported for Yukon soil-isolated strains of Mortierella alpina and Penicillium expansum that are natural enemies to larvae(infestation stage)of the winter tick Dermacentor albipictus.Both fungal strains are psychrotrophs,characterized by low thermal growth ranges,consistent with their occurrence in Yukon soil.In contrast to P.expansum,M.alpina is more temperature sensitive,has a higher requirement,and is more virulent to tick larvae.Researchers and Biological Control Officers should note that for tick population control these M.alpina and P.expansum strains grow and sporulate well under moderate temperature and humid conditions.Our experiments used Met52®Bioinsecticide as a positive control,and this is the first study that demonstrates the effectiveness of this commercial product against winter tick larvae.展开更多
Fungal composition of Yukon soil samples consisted of 29 soil saprobes common to acidified forest,subarctic habitats.All of the fungi identified are psychrotrophs,capable of growth at both 4℃ and 20℃.Of these,a tota...Fungal composition of Yukon soil samples consisted of 29 soil saprobes common to acidified forest,subarctic habitats.All of the fungi identified are psychrotrophs,capable of growth at both 4℃ and 20℃.Of these,a total of 17 fungi were found to be entomopathogenic by winter tick(Dermacentor albipictus)larval bioassays:Aspergillus flavus,Beauveria,namely B.bassiana,Mucor,Paecilomyces yielded>~70%larval mortality and the remainder,mostly Mortierella and Penicillium,averaged~40%larval mortality.Sites where elk(Cervus elaphus canadensis)are observed had an overall greater quantity,and diversity of entomopathogenic soil fungi than sites where elk are not observed.Greater diversity of fungi at elk-inhabited sites is likely a product of warmer soil microclimate(hillsides where elk are seen,lose snow earlier than other areas),animal presence,and increased nutrient enrichment.We conclude that Yukon soils contain fungi that naturally regulate populations of D.albipictus.All fungi are archived at the Wittenberg University Fungus Collection,Springfield,OH,USA.展开更多
We report differences in secondary resource capture and upper lethal temperature as survival attributes for Fusarium oxysporum(FOSC)and Rhizopus stolonifer,two medically important fungi that were co-isolated from a ta...We report differences in secondary resource capture and upper lethal temperature as survival attributes for Fusarium oxysporum(FOSC)and Rhizopus stolonifer,two medically important fungi that were co-isolated from a table shower caddy.Isolates of these two shower-associated fungi have been deposited at the University of Alberta Microfungus Collection and Herbarium,Centre for Global Microfungal Biodiversity(UAMH,Toronto,CAN)as R.stolonifer UAMH 11965 and F.oxysporum(FOSC)UAMH 11966;this paper provides growth characteristics for these two strains that can be used for further studies on black molds in bathrooms given the relevance to public health.Both R.stolonifer UAMH 11965 and F.oxysporum(FOSC)UAMH 11966 require contact with a wet surface substrate with water activity≥0.95 aw for growth and sporulation.In contrast to F.oxysporum,R.stolonifer has a 4-6x,faster radial growth rate,superior colonizing ability,and capacity for overgrowth(exploitative competition).This F.oxysporum(FOSC)strain,however,is thermotolerant,as demonstrated by broader thermal growth range and higher optimum temperature,which puts fewer limitations on its growth compared to R.stolonifer.This is a point of public awareness for mold-sensitive and immunocompromised people that wet,wood substrates in a shower can permit colonization and competitive interactions that can concentrate R.stolonifer and F.oxysporum spores.展开更多
文摘Water activity-temperature relationships are reported for Yukon soil-isolated strains of Mortierella alpina and Penicillium expansum that are natural enemies to larvae(infestation stage)of the winter tick Dermacentor albipictus.Both fungal strains are psychrotrophs,characterized by low thermal growth ranges,consistent with their occurrence in Yukon soil.In contrast to P.expansum,M.alpina is more temperature sensitive,has a higher requirement,and is more virulent to tick larvae.Researchers and Biological Control Officers should note that for tick population control these M.alpina and P.expansum strains grow and sporulate well under moderate temperature and humid conditions.Our experiments used Met52®Bioinsecticide as a positive control,and this is the first study that demonstrates the effectiveness of this commercial product against winter tick larvae.
文摘Fungal composition of Yukon soil samples consisted of 29 soil saprobes common to acidified forest,subarctic habitats.All of the fungi identified are psychrotrophs,capable of growth at both 4℃ and 20℃.Of these,a total of 17 fungi were found to be entomopathogenic by winter tick(Dermacentor albipictus)larval bioassays:Aspergillus flavus,Beauveria,namely B.bassiana,Mucor,Paecilomyces yielded>~70%larval mortality and the remainder,mostly Mortierella and Penicillium,averaged~40%larval mortality.Sites where elk(Cervus elaphus canadensis)are observed had an overall greater quantity,and diversity of entomopathogenic soil fungi than sites where elk are not observed.Greater diversity of fungi at elk-inhabited sites is likely a product of warmer soil microclimate(hillsides where elk are seen,lose snow earlier than other areas),animal presence,and increased nutrient enrichment.We conclude that Yukon soils contain fungi that naturally regulate populations of D.albipictus.All fungi are archived at the Wittenberg University Fungus Collection,Springfield,OH,USA.
基金Funded by a gift from Elizabeth E.Powelson to the Department of Biology for support of undergraduate research at Wittenberg University.
文摘We report differences in secondary resource capture and upper lethal temperature as survival attributes for Fusarium oxysporum(FOSC)and Rhizopus stolonifer,two medically important fungi that were co-isolated from a table shower caddy.Isolates of these two shower-associated fungi have been deposited at the University of Alberta Microfungus Collection and Herbarium,Centre for Global Microfungal Biodiversity(UAMH,Toronto,CAN)as R.stolonifer UAMH 11965 and F.oxysporum(FOSC)UAMH 11966;this paper provides growth characteristics for these two strains that can be used for further studies on black molds in bathrooms given the relevance to public health.Both R.stolonifer UAMH 11965 and F.oxysporum(FOSC)UAMH 11966 require contact with a wet surface substrate with water activity≥0.95 aw for growth and sporulation.In contrast to F.oxysporum,R.stolonifer has a 4-6x,faster radial growth rate,superior colonizing ability,and capacity for overgrowth(exploitative competition).This F.oxysporum(FOSC)strain,however,is thermotolerant,as demonstrated by broader thermal growth range and higher optimum temperature,which puts fewer limitations on its growth compared to R.stolonifer.This is a point of public awareness for mold-sensitive and immunocompromised people that wet,wood substrates in a shower can permit colonization and competitive interactions that can concentrate R.stolonifer and F.oxysporum spores.
