scholarly journals Cellular and extracellular siderophores of Aspergillus nidulans and Penicillium chrysogenum.

1981 ◽  
Vol 1 (2) ◽  
pp. 94-100 ◽  
Author(s):  
G Charlang ◽  
B Ng ◽  
N H Horowitz ◽  
R M Horowitz
Keyword(s):  
Biological Activity ◽  
Neurospora Crassa ◽  
Aspergillus Nidulans ◽  
Water Activity ◽  
Penicillium Chrysogenum ◽  
Mycelial Growth ◽  
Culture Medium ◽  
Highly Active ◽  
Assay Procedure ◽  
Generally True

Aspergillus nidulans and Penicillium chrysogenum produce specific cellular siderophores in addition to the well-known siderophores of the culture medium. Since this was found previously in Neurospora crassa, it is probably generally true for filamentous ascomycetes. The cellular siderophore of A. nidulans is ferricrocin; that of P. chrysogenum is ferrichrome. A. nidulans also contains triacetylfusigen, a siderophore without apparent biological activity. Conidia of both species lose siderophores at high salt concentrations and become siderophore dependent. This has also been found in N. crassa, where lowering of the water activity has been shown to be the causal factor. We used an assay procedure based on this dependency to reexamine the extracellular siderophores of these species. During rapid mycelial growth, both A. nidulans and P. chrysogenum produced two highly active, unidentified siderophores which were later replaced by a less active or inactive product--coprogen in the case of P. chrysogenum and triacetylfusigen in the case of A. nidulans. N. crassa secreted coprogen only. Fungal siderophore metabolism is varied and complex.

scholarly journals Cellular and extracellular siderophores of Aspergillus nidulans and Penicillium chrysogenum

1981 ◽  
Vol 1 (2) ◽  
pp. 94-100
Author(s):  
G Charlang ◽  
B Ng ◽  
N H Horowitz ◽  
R M Horowitz
Keyword(s):  
Biological Activity ◽  
Neurospora Crassa ◽  
Aspergillus Nidulans ◽  
Water Activity ◽  
Penicillium Chrysogenum ◽  
Mycelial Growth ◽  
Culture Medium ◽  
Highly Active ◽  
Assay Procedure ◽  
Generally True

Aspergillus nidulans and Penicillium chrysogenum produce specific cellular siderophores in addition to the well-known siderophores of the culture medium. Since this was found previously in Neurospora crassa, it is probably generally true for filamentous ascomycetes. The cellular siderophore of A. nidulans is ferricrocin; that of P. chrysogenum is ferrichrome. A. nidulans also contains triacetylfusigen, a siderophore without apparent biological activity. Conidia of both species lose siderophores at high salt concentrations and become siderophore dependent. This has also been found in N. crassa, where lowering of the water activity has been shown to be the causal factor. We used an assay procedure based on this dependency to reexamine the extracellular siderophores of these species. During rapid mycelial growth, both A. nidulans and P. chrysogenum produced two highly active, unidentified siderophores which were later replaced by a less active or inactive product--coprogen in the case of P. chrysogenum and triacetylfusigen in the case of A. nidulans. N. crassa secreted coprogen only. Fungal siderophore metabolism is varied and complex.

Biological activity of Pyraclostrobin against Coniella granati causing pomegranate crown rot

Plant Disease ◽  
2021 ◽  
Author(s):  
Xue Yang ◽  
Chun-Yan Gu ◽  
Yang Bai ◽  
Jia-Zhi Sun ◽  
Hao-Yu Zang ◽  
...  
Keyword(s):  
Biological Activity ◽  
Mycelial Growth ◽  
Field Trials ◽  
Crown Rot ◽  
Germination Inhibition ◽  
Control Efficacy ◽  
Intracellular Organelle ◽  
Transmission Electron ◽  
Excellent Control ◽  
Conidium Germination

Pomegranate crown rot caused by Coniellagranati is one of the most severe diseases of pomegranate. To date, no fungicides have been registered for controlling this disease in China. Pyraclostrobin, belonging to strobilurin fungicides, has a broad spectrum of activity against many phytopathogens. In this study, based on the mycelial growth and conidial germination inhibition methods, we investigated the biological activity of pyraclostrobin against C. granati at the presence of 50 μg/mL SHAM using 80 isolates collected from different orchards in China during 2012-2018. The EC50 (50% effective concentration) values ranged from 0.040-0.613 μg/mL for mycelial growth and 0.013-0.110 μg/mL for conidium germination, respectively. Treated with pyraclostrobin, the hyphae morphology changed and conidial production of C. granati decreased significantly. The result of transmission electron microscope showed that treatment of pyraclostrobin could make the cell wall thinner, and lead to ruptured cell membrane and formation of intracellular organelle autophagosomes. The pyraclostrobin showed good protective and curative activities against C. granati on detached pomegranate fruits. In field trials, pyraclostrobin showed excellent control efficacy against this disease in which the treatment of 25% pyraclostrobin EC 1000× provided 92.25% and 92.58% control efficacy in 2019 and 2020, respectively, significantly higher than that of other treatments. Therefore, pyraclostrobin could be a candidate fungicide for the control of pomegranate crown rot.

scholarly journals Effects of water activity on the performance of potassium sorbate and natamycin as preservatives against cheese spoilage moulds

2017 ◽  
Vol 56 (1) ◽  
pp. 85-92 ◽  
Author(s):  
P. Marín ◽  
C. Ginés ◽  
P. Kochaki ◽  
M. Jurado
Keyword(s):  
Sodium Chloride ◽  
Water Activity ◽  
Penicillium Chrysogenum ◽  
Potassium Sorbate ◽  
Mucor Racemosus ◽  
Food Preservatives ◽  
Glycerol Water ◽  
Fungal Inhibition ◽  
Growth Of Fungi ◽  
Different Levels

AbstractThis work investigated the effects of the food preservatives potassium sorbate and natamycin, combined with different levels of ionic (sodium chloride) and non-ioinic (glycerol) water activity (aw), on growth of fungi involved in cheese spoilage. In general, the combined effect of water stress and presence of preservatives enhanced fungal inhibition. However, some doses of potassium sorbate (0.02%) and natamycin (1, 5 and 10 ppm) were able to stimulate growth of Aspergillus varians, Mucor racemosus, Penicillium chrysogenum and P. roqueforti at awvalues in the range of 0.93–0.97. P. solitum was the only species whose growth was consistently reduced by any doses of preservative. The results also showed that sodium chloride and glycerol differentially affected the efficacy of preservatives. This study indicates that awof cheese is a critical parameter to be considered in the formulation of preservative coatings used against fungal spoilage.

scholarly journals Maintenance culture medium and inoculum based on peach palm leaves for Pleurotus spp. production

2016 ◽  
Vol 83 (0) ◽  
Author(s):  
Elisabeth Wisbeck ◽  
Endi Pricila Alves ◽  
Styfanie Gonçalves de Lima ◽  
Regina Maria Miranda Gern ◽  
Marcia Luciane Lange Silveira ◽  
...  
Keyword(s):  
Radial Velocity ◽  
Mycelial Growth ◽  
Culture Medium ◽  
Agricultural Waste ◽  
Production Costs ◽  
Fruiting Bodies ◽  
Wheat Grains ◽  
Peach Palm ◽  
Maintenance Medium ◽  
Production Parameters

ABSTRACT: This study evaluated the use of immersion water from peach palm leaves (PPLDA) as a component of the culture medium for the maintenance of Pleurotus spp. and the use of agricultural waste, peach palm leaves, as inoculum support for the fungi. The performance of the inoculum based on peach palm leaves (PPL) for the production of Pleurotus spp. fruiting bodies was compared with that using wheat grains (WG) as inoculum support. PPLDA culture medium (immersion water of peach palm leaves, dextrose, and agar) showed a lower radial velocity of mycelial growth for both fungi than that obtained with the culture medium WDA (wheat extract, dextrose and agar), commonly used as maintenance medium for Pleurotus spp. However, the type of inoculum support does not significantly influence the linear velocity of P. ostreatus mycelial growth, reaching 6.71 mm/day on wheat grains and 6.18 mm/day on peach palm leaves. Thus, when the inoculum based on peach palm leaves is utilized, the immersion water used for preparing this support can be used for preparing the PPLDA maintenance culture medium, diminishing the production costs of Pleurotus mushrooms. Data also showed that when Pleurotus sajor-caju was cultivated on peach palm leaves, using PPL as inoculum support, the fruiting bodies production parameters (Y = 47%, BE = 3% and Pr = 0.2 g/day) did not differ from that obtained using WG.

scholarly journals Effect water activity on in vitro mycelial growth of Neofusicoccum spp. infecting blueberry

2012 ◽  
Vol 39 (1) ◽  
pp. 221-228 ◽  
Author(s):  
Bernardo A Latorre ◽  
Gonzalo A Díaz ◽  
María P Reed
Keyword(s):  
Water Activity ◽  
Mycelial Growth
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