Growth of Penicillium expansum and production of patulin in potato-glucose-agar medium supplemented with imazalil

Author(s):  
F.M. Valle-Algarra ◽  
Eva M. Mateo ◽  
F. Mateo ◽  
J.V. Gimeno-Adelantado ◽  
M. Jiménez
1990 ◽  
Vol 69 (8) ◽  
pp. 1480-1484 ◽  
Author(s):  
D.A. Young ◽  
W.H. Bowen

Sucralose (1',4',6' trideoxy-trichloro-galactosucrose) is a nontoxic, intensely sweet sucrose derivative that has been shown to be non-cariogenic in experimental animals. The purpose of this study was to determine whether certain oral bacteria could utilize sucralose. Sucralose, as a sole carbon source, was unable to support growth of ten strains of oral bacteria and dental plaque. When sucralose was incorporated into a liquid medium containing glucose or sucrose, all organisms tested displayed similar pH falls, compared with controls. The incorporation of 126 mmol/L sucralose into glucose agar medium caused total inhibition of growth of Streptococcus sobrinus 6715-17, Streptococcus sanguis 10904, Streptococcus sanguis Challis, Streptococcus salivarius, and Actinomyces viscosus WVU627. Sucralose had no effect on IPS production. Sucralose was not bound to, nor taken up by, cells. Sucralose inhibited the formation of glucan and fructan polymers in proportion to the sucralose-to-enzyme ratio, but independent of the sucrose concentration in the assay mixture. No radioactive polymer was formed from 14C-U-sucralose added to mixtures containing glucosyltransferase (GTF) or fructosyltransferase (FTF). Inhibition of GTF and FTF by sucralose was removed following dialysis of the enzyme/sucralose mixture. These results show that sucralose was not utilized by the oral bacteria tested and that the inhibitory effect of sucralose on GTF and FTF was non-competitive and reversible. The results further support the concept that sucralose is non-cariogenic.


1965 ◽  
Vol 11 (2) ◽  
pp. 213-219 ◽  
Author(s):  
Richard S. Berk

A survey of 75 cultures of Pseudomonas aeruginosa containing only one discernible phenotype indicated that 68 routinely exhibited spontaneous lysis, resulting in the appearance of turbid erosions or autoplaques (AP+) when grown on a tryptone–glucose agar medium. Single supplements of non-inhibitory levels of chloromycetin, aureomycin, tetracycline, declomycin, and streptomycin increased the degree of lysis of AP+ strains, but were without effect on AP− strains. Enhancement of lysis was also obtained with sulfadiazine, sulfathiazole, sulfamethoxypyridazine, elkosin, gantrisin, and triple sulfa, while little or no effect was observed with sulfamerizine and thiosulfil. On the other hand, low concentrations of either acriflavine or proflavine retarded the rate and degree of lysis, while single supplements of the active antibiotics overcame the suppressive effects of the dyes.


2012 ◽  
Vol 60 (2) ◽  
pp. 109-129 ◽  
Author(s):  
I. Csöndes

Macrophomina phaseolina (Tassi) Goidanich can cause serious yield losses in several plant species. Investigations were made on the colony morphology of fifty Macrophomina phaseolina isolates from Hungary, one from Spain and two from Serbia on six different culture media to detect differences between the isolates. The fungus exhibited the most intensive growth on maize-flour agar, followed by the Sabouraud-glucose, maltextract, potato-dextrose, Czapek-Dox and watery agar media. Investigations on the macromorphology of the isolates revealed different extents of aerial mycelia formation and differences in the zonal structure of microsclerotial formation on the individual media. One isolate (Mp 38) turned the Sabouraud-glucose agar medium pale pink. Investigations on the micromorphology of the cultures showed that the isolates also varied with respect to microsclerotial characters (size, shape and production of microsclerotia). The microsclerotia of this fungal pathogen had the greatest diameter (averaging 135.31 μm) on Sabouraud-glucose agar medium. This study was the first in Hungary to prove that Macrophomina phaseolina could be grown on nutrient-deficient watery agar, suggesting that it can tolerate a wide range of ecological circumstances.


2003 ◽  
Vol 66 (8) ◽  
pp. 1503-1505 ◽  
Author(s):  
DERRICK O. OKULL ◽  
ROBERT B. BEELMAN ◽  
HASSAN GOURAMA

In mushrooms, 10-oxo-trans-8-decenoic acid (ODA) and 1-octen-3-ol are secondary metabolites produced naturally by the enzymatic breakdown of linoleic acid. Both compounds were determined to inhibit the mycelial growth of Penicillium expansum PP497A, a common food spoilage organism, when added to potato dextrose agar medium. ODA and 1-octen-3-ol were inhibitory at concentrations of >1.25 mM (230 μg/g for ODA and 160 μg/g for 1-octen-3-ol). At pH 5.6, 1-octen-3-ol was more inhibitory than ODA. However, at pH 3.5, both compounds (especially ODA) were more inhibitory than they were at pH 5.6. This finding indicates that the undissociated carboxyl of ODA was important for inhibition. At a concentration of 2.5 mM and a pH of 3.5, ODA and 1-octen-3-ol inhibited growth by 43.1 and 41.9%, respectively. An additive effect was observed when both compounds were added at a combined concentration of ≥1.25 mM; when both were added at a combined concentration of 2.5 mM, mycelial growth was inhibited by 48.8 and 72.8% at pHs of 5.6 and 3.5, respectively. Although the antifungal activity levels for these two compounds were lower than those observed for equal molar concentrations of sorbate, a common antifungal compound, these findings indicate that further investigation of the potential of ODA and 1-octen-3-ol for use as natural food preservatives is warranted.


2014 ◽  
Vol 30 (2) ◽  
pp. 223-232
Author(s):  
Janusz Błaszkowski

Using a biotic series method, interactions between <i>Sepfona nodorum</i> and associated fungal communities isolated from leaves, glumes, and seeds of spring <i>Triticum acstivum</i>. cv. Kolibri treated with Bayleton 25 WP. Dithane M-45. and Funaben K were determined. Control planls were sprayed with water. Most fungi accompanying <i>S. nodorum</i> in the field inhibited the growth of this pathogen on a potato glucose agar medium. Fungi which restricted the growth of <i>S. nodorum</i> the most were <i>Chaetomium globosum, Fusarium</i> spp., <i>Helminthosporium sativum, Mucor hiemalis, Rbizophus nigrieans, Stemphylium botryosum, Trichothecium roseum</i>, and two non-sporulating forms. <i>Septoria nodorum</i> replaced <i>Cladosporium</i> spp. and a yeast-like pink fungus. The biotic resistance to <i>S. nodorum</i> increased with me age of plant. The fungal populations recovered from plants sampled in 1982 and 1983 inhibited the growth of <i>S. nodorum</i> whereas most of those isolated in the relatively wet and cold year 1984 favoured the development of this pathogen, The lowest biotic resistance of the fungal communities investigated to <i>S. nodorum</i> was generally found following spraying of plant s with Bayleton 25 WP, and ihe highest in Funabed K - and water-treated plants.


2005 ◽  
Vol 68 (6) ◽  
pp. 1203-1207 ◽  
Author(s):  
PHILIPPE DANTIGNY ◽  
IAVOR TCHOBANOV ◽  
MAURICE BENSOUSSAN ◽  
MARCEL H. ZWIETERING

The influence of ethanol vapor on germination of Penicillium chrysogenum was determined on yeast nitrogen base plus glucose agar medium at 25°C. Ethanol vapors were generated by 0 to 6% (wt/wt) ethanol solutions at the bottom of hermetically closed petri dishes. The logistic equation was used to describe the data as the percentage of germination versus time and to estimate the germination time. The effect of ethanol concentration on germination time was described by a new reparameterized equation, resulting in an estimated limiting ethanol concentration of 4.3%. Up to 3% ethanol, all spores germinated, and the germination time increased with increasing ethanol concentration. At 3.5 and 4%, some spores formed abnormal germ tubes and others were inhibited at the swelling stage. The inhibiting effect of ethanol was reversible under these experimental conditions.


2009 ◽  
Vol 1 (2) ◽  
Author(s):  
Risa Nofiani ◽  
Siti Nurbetty ◽  
Ajuk Sapar

<p>The increase of issues on the antibiotics resistant pathogenic bacteria has triggered high exploration for new antimicrobial compounds. One of the potential sources is sponge-associated bacteria. The aim of this study was to get sponge-associated bacteria extract containing antimicrobial activities. On the basis screening of antimicrobial activity using by streaking on agar medium, there were two potential isolates with antimicrobial activities namely LCS1 and LCS2. The two isolates were cultivated,then secondary metabolite product were extracted using methanol as a solvent. Minimum inhibitory concentrations (MICs) of extract LCS 1 were 1,000 μg/well for S. aureus, 950 μg/well for Salmonella sp.and 800 μg/well for Bacillus subtilis. Minimum inhibitory concentrations of extract LCS 2 were 500 μg/well for S. aureus, 1,050 μg/well for Salmonella sp., 750 μg/well for Bacillus subtilis, 350 μg/well for P. aeruginosa, 750 μg/sumur terhadap B. subtilis. Based on the MIC values, the two assay extracts have a relatively low antimicrobial activity.</p> <p>Keywords:Antimicrobial,Sponges associated bacteria,MICs</p>


2018 ◽  
Vol 69 (8) ◽  
pp. 1927-1933 ◽  
Author(s):  
Mariana Deleanu ◽  
Elisabeta E. Popa ◽  
Mona E. Popa

The compounds in Ginger (Zingiber officinale-Roscoe) essential oil provenience China and wild oregano (Origanum vulgare) essential oil of Romanian origin were identified by GC/MS and their antioxidant and antifungal properties were evaluated. Wild oregano oil was characterized by high content of oxygenated monoterpenes hydrocarbons (84.05%) of which carvacrol was the most abundant (73.85%) followed by b-linalool (3.46%) and thymol (2.29%). Ginger oil had a higher content of sesquiterpene hydrocarbons including zingiberene (31.47%), b-sesquiphellandrene (13.76%), a-curcumene (10.41%), a-farnesene (8.31%) and b-bisabolene (7.55%) but a lower content of oxygenated monoterpenes (7.97%). The high content of oxygenated monoterpens of wild oregano oil is in accordance with total content of polyphenols determined by the Folin�Ciocalteu method (6.71�0.73 mg of gallic acid equivalent per g oil). Ginger oil had only 1.34�0.22 mg gallic acid equivalent per g oil. Wild oregano oils exhibited appreciable in vitro antioxidant activity as assessed by 2, 2`-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and 2,2�-azino-bis (3 ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS). The sample concentration required to scavenge 50% of the DPPH free radicals was 0.76�0.13 mg/mL for wild oregano oil compared to 20.22�2.12 mg/mL for ginger oil. Also, wild oregano oils showed significant inhibitory activity against selected pathogenic fungi (Fusarium oxysporum, Aspergillus flavus and Penicillium expansum). 1�L of oregano oil is sufficient for almost 75% growth inhibition of Aspergillus flavus compared to ginger oil which shows antifungal activity at 240�L for 78% growth inhibition. It can be concluded that wild oregano oil could be used as food preservative in some food products in which Fusarium oxysporum, Aspergillus flavus and Penicillium expansum could grow and have potential to produce health hazards mycotoxines.


Sign in / Sign up

Export Citation Format

Share Document