Claudio Ciccarone

Influence of temperature, pH and water activity on in vitro inhibition of Penicillium glabrum (Wehmer) Westling by yeasts

Four different yeast species (Metschnikowia pulcherrima, Saccharomycopsis vini, Kluyveromyces marxianus, Cryptococcus albidus), isolated from surface of grapes, were evaluated for biocontrol potential against Penicillium glabrum. In order to investigate the influence of temperature, pH, water activity and yeast cell concentration on Penicillium glabrum inhibition, the individual effects and the interaction of these factors were analyzed by means of a Central Composite Design (CCD). All yeast species tested showed antagonistic effects which were more pronounced at high cell concentrations. The other variables affected the antagonistic effect differentially depending on the yeast species. Results of the experimental design showed that the selective success of a competitive microflora is under environmental control; moreover, when microbial cells are subjected to multiple factors, the effects and the reciprocal interactions of the individual variables cannot be independently evaluated.

Biodiversity of emerging pathogenic and invasive fungi in plants, animals and humans in Italy

Abstract In the last 30 years, the spread of emerging and invasive fungal pathogens has had a profound impact on plants, animals and humans, causing crop losses and damaging their health with economic and social impact. Awareness of the biodiversity of these pathogens is essential for their detection, identification and control. In this article, their diversity in Italy is reviewed taking into consideration the international context. Fungal endophytes, important ecological agents whose lifestyle can be switched by stochastic events from beneficial/neutral to pathogenic, are included in this review.

A study on micro-fungi in arid areas. Notes on stress-tolerant fungi

ABSTRACT Severe selectivity by extreme environments was investigated in mitosporic fungi with regard to their adaptive responses to high temperature, and to high levels of sunlight and evapo-transpiration. A homogeneous group of graminicolous dematiaceous hyphomycetes was removed from sand dunes in the torrid climate of the Namib Naukluft Park, from arid, clayey soil at Etosha pan and from calcareous crusts in the Namib Desert Park: all of them produce darkening conidiophores and deeply pigmented spores. The size and colour of reproductive structures were recorded and compared with bibliographic data. Results are consistent with a uniform morpho-functional response by these fungi to stress conditions.

Use of microfungi in the treatment of oak chips: possible effects on wine.

BACKGROUND Oak barrels are commonly used in the aging of wines and spirits because of their positive effects on the product. In recent years the addition of oak chips has been used to introduce desirable wood aromas and flavours into wines. In this study, oak chips in saline solution or laboratory medium were inoculated with Penicillium purpurogenum, Aureobasidium pullulans, Phialemonium obovatum, Phanerochaete chrysosporium and a combination of Ph. chrysosporium and A. pullulans. After 12 weeks of incubation, oak chips (2 g L(-1)) were macerated in a red wine for 17 days. Gas chromatography/mass spectrometry and high-performance liquid chromatography were used to evaluate 14 compounds, namely furfural, furfuryl alcohol, guaiacol, syringol, cis-β-methyl-γ-octalactone, 2-phenylethanol, 4-vinylguaiacol, benzyl alcohol, 2,3-butanediol, γ-butyrolactone, benzaldehyde, 4-ethylguaiacol, gallic acid and ellagic acid. RESULTS The microfungal treatments increased the concentration of some components. In particular, P. purpurogenum resulted in a significant improvement in the levels of guaiacol, furfural, syringol, furfuryl alcohol and 2-phenylethanol. CONCLUSION Penicillium purpurogenum and Ph. chrysosporium showed a constant trend (enrichment of furfural and benzaldehyde) independent to some extent of the medium used for chip treatment.

A study on micro-fungi in arid areas: Notes on soil saprotrophs and animal opportunistic pathogens

ABSTRACT Soil fungi were studied in three desert areas in Namibia with the aim of identifying saprotrophic microorganisms associated with animal communities as opportunistic pathogens. The extremely arid environment of the Naukluft Desert Park was found to be more selective for soil fungi, whereas the soils of Etosha Pan, with seasonal wet areas, and the mobile dunes of Sossousvlei, which absorb atmospheric moisture at night by virtue of their proximity to the sea, host saprotrophic microorganisms and potential and/or opportunistic pathogens.

Two new Dematiaceous Hyphomycetes from humid tropic forest litter

Abstract Two Dematiaceous Hyphomycetes, Beltraniella lyrata and Beltraniopsis fabularis, found on tropical forest litter in the Tai National Park in Ivory Coast are proposed as new species and described.

Artificial aging of Uva di Troia and Primitivo wines using oak chips inoculated with Penicillium purpurogenum

BACKGROUND Two red wines (Primitivo and Uva di Troia) treated with oak chips inoculated with Penicillium purpurogenum were analysed in order to assess their contents of furfural, cis-β-methyl-γ-octalactone, syringol, eugenol, vanillin and 4-vinylguaiacol. Two different sizes of oak chips (small and big, of length 2 and 8 mm respectively) and two different degrees of toasting (low and high) were used in the study. Aroma compounds were analysed by gas chromatography/mass spectrometry to determine differences among samples after 15 days of chip contact time. RESULTS Big oak chips inoculated with P. purpurogenum increased the level of 4-vinylguaiacol, while small oak chips inoculated with P. purpurogenum, in some conditions, increased the level of eugenol. Chip size and degree of toasting also played an important role in the content of eugenol. CONCLUSION The use of oak chips inoculated with mould might be a promising alternative to barrel aging. Moreover, different fungal inocula could contribute to the enrichment of wine with specific compounds (e.g. 4-vinylguaiacol and eugenol).

Ricerche sulla specializzazione tra funghi saprotrofi e matrici vegetali

Abstract Survey on specialization between saprotrophic fungi and vegetables matrices. - The relationships between some saprotrophic fungi and their natural matrices, collected in the Tai National Park (Ivory Coast) are investigated. The data seem to confirm a sort of specialization of the above mentioned orgamisms (18 Dematiaceous Hyphomycetes) on the different species composing the litter layer (10 matrices) as a result of various environmental factors.

Evaluation of Fungal Growth on Olive-Mill Wastewaters Treated at High Temperature and by High-Pressure Homogenization

Reuse of olive mill wastewaters (OMWWs) in agriculture represents a significant challenge for health and safety of our planet. Phytotoxic compounds in OMWW generally prohibit use of untreated OMWWs for agricultural irrigation or direct discharge into surface waters. However, pretreated OMWW can have positive effects on chemical and microbiological soil characteristics, to fight against fungal soil-borne pathogens. Low amounts of OMWW following thermal (TT-OMWW) and high-pressure homogenization (HPH-OMWW) pretreatments counteracted growth of some of 12 soil-borne and/or pathogenic fungi examined. With fungal growth measured as standardized change in time to half maximum colony diameter, Δτ, overall, HPH-OMWW showed increased bioactivity, as increased mean Δτ from 3.0 to 4.8 days. Principal component analysis highlighted two fungal groups: Colletotrichum gloeosporioides, Alternaria alternata, Sclerotium rolfsii, and Rosellinia necatrix, with growth strongly inhibited by the treated OMWWs; and Aspergillus ochraceus and Phaeoacremonium parasiticum, with stimulated growth by the treated OMWWs. As a non-thermal treatment, HPH-OMWW generally shows improved positive effects, which potentially arise from preservation of the phenols.