Ippolito Camele

Fungal Planet description sheets: 214-280

Novel species of microfungi described in the present study include the following from South Africa: Cercosporella dolichandrae from Dolichandra unguiscati, Seiridium podocarpi from Podocarpus latifolius, Pseudocercospora parapseudarthriae from Pseudarthria hookeri, Neodevriesia coryneliae from Corynelia uberata on leaves of Afrocarpus falcatus, Ramichloridium eucleae from Euclea undulata and Stachybotrys aloeticola from Aloe sp. (South Africa), as novel member of the Stachybotriaceae fam. nov. Several species were also described from Zambia, and these include Chaetomella zambiensis on unknown Fabaceae, Schizoparme pseudogranati from Terminalia stuhlmannii, Diaporthe isoberliniae from Isoberlinia angolensis, Peyronellaea combreti from Combretum mossambiciensis, Zasmidium rothmanniae and Phaeococcomyces rothmanniae from Rothmannia engleriana, Diaporthe vangueriae from Vangueria infausta and Diaporthe parapterocarpi from Pterocarpus brenanii. Novel species from the Netherlands include: Stagonospora trichophoricola, Keissleriella trichophoricola and Dinemasporium trichophoricola from Trichophorum cespitosum, Phaeosphaeria poae, Keissleriella poagena, Phaeosphaeria poagena, Parastagonospora poagena and Pyrenochaetopsis poae from Poa sp., Septoriella oudemansii from Phragmites australis and Dendryphion europaeum from Hedera helix (Germany) and Heracleum sphondylium (the Netherlands). Novel species from Australia include: Anungitea eucalyptorum from Eucalyptus leaf litter, Beltraniopsis neolitseae and Acrodontium neolitseae from Neolitsea australiensis, Beltraniella endiandrae from Endiandra introrsa, Phaeophleospora parsoniae from Parsonia straminea, Penicillifer martinii from Cynodon dactylon, Ochroconis macrozamiae from Macrozamia leaf litter, Triposporium cycadicola, Circinotrichum cycadis, Cladosporium cycadicola and Acrocalymma cycadis from Cycas spp. Furthermore, Vermiculariopsiella dichapetali is described from Dichapetalum rhodesicum (Botswana), Ophiognomonia acadiensis from Picea rubens (Canada), Setophoma vernoniae from Vernonia polyanthes and Penicillium restingae from soil (Brazil), Pseudolachnella guaviyunis from Myrcianthes pungens (Uruguay) and Pseudocercospora neriicola from Nerium oleander (Italy). Novelties from Spain include: Dendryphiella eucalyptorum from Eucalyptus globulus, Conioscypha minutispora from dead wood, Diplogelasinospora moalensis and Pseudoneurospora canariensis from soil and Inocybe lanatopurpurea from reforested woodland of Pinus spp. Novelties from France include: Kellermania triseptata from Agave angustifolia, Zetiasplozna acaciae from Acacia melanoxylon, Pyrenochaeta pinicola from Pinus sp. and Pseudonectria rusci from Ruscus aculeatus. New species from China include: Dematiocladium celtidicola from Celtis bungeana, Beltrania pseudorhombica, Chaetopsina beijingensis and Toxicocladosporium pini from Pinus spp. and Setophaeosphaeria badalingensis from Hemerocallis fulva. Novel genera of Ascomycetes include Alfaria from Cyperus esculentus (Spain), Rinaldiella from a contaminated human lesion (Georgia), Hyalocladosporiella from Tectona grandis (Brazil), Pseudoacremonium from Saccharum spontaneum and Melnikomyces from leaf litter (Vietnam), Annellosympodiella from Juniperus procera (Ethiopia), Neoceratosperma from Eucalyptus leaves (Thailand), Ramopenidiella from Cycas calcicola (Australia), Cephalotrichiella from air in the Netherlands, Neocamarosporium from Mesembryanthemum sp. and Acervuloseptoria from Ziziphus mucronata (South Africa) and Setophaeosphaeria from Hemerocallis fulva (China). Several novel combinations are also introduced, namely for Phaeosphaeria setosa as Setophaeosphaeria setosa, Phoma heteroderae as Peyronellaea heteroderae and Phyllosticta maydis as Peyronellaea maydis. Morphological and culture characteristics along with ITS DNA barcodes are provided for all taxa.

In Vitro Control of Post-Harvest Fruit Rot Fungi by Some Plant Essential Oil Components

Eight substances that are main components of the essential oils from three Mediterranean aromatic plants (Verbena officinalis, Thymus vulgaris and Origanum vulgare), previously found active against some phytopathogenic Fungi and Stramenopila, have been tested in vitro against five etiological agents of post-harvest fruit decay, Botrytis cinerea, Penicillium italicum, P. expansum, Phytophthora citrophthora and Rhizopus stolonifer. The tested compounds were β-fellandrene, β-pinene, camphene, carvacrol, citral, o-cymene, γ-terpinene and thymol. Citral exhibited a fungicidal action against P. citrophthora; carvacrol and thymol showed a fungistatic activity against P. citrophthora and R. stolonifer. Citral and carvacrol at 250 ppm, and thymol at 150 and 250 ppm stopped the growth of B. cinerea. Moreover, thymol showed fungistatic and fungicidal action against P. italicum. Finally, the mycelium growth of P. expansum was inhibited in the presence of 250 ppm of thymol and carvacrol. These results represent an important step toward the goal to use some essential oils or their components as natural preservatives for fruits and foodstuffs, due to their safety for consumer healthy and positive effect on shelf life extension of agricultural fresh products.

In Vitro Antifungal Activity of Burkholderia gladioli pv. agaricicola against Some Phytopathogenic Fungi

The trend to search novel microbial natural biocides has recently been increasing in order to avoid the environmental pollution from use of synthetic pesticides. Among these novel natural biocides are the bioactive secondary metabolites of Burkholderia gladioli pv. agaricicola (Bga). The aim of this study is to determine antifungal activity of Bga strains against some phytopathogenic fungi. The fungicidal tests were carried out using cultures and cell-free culture filtrates against Botrytis cinerea, Aspergillus flavus, Aspergillus niger, Penicillium digitatum, Penicillium expansum, Sclerotinia sclerotiorum and Phytophthora cactorum. Results demonstrated that all tested strains exert antifungal activity against all studied fungi by producing diffusible metabolites which are correlated with their ability to produce extracellular hydrolytic enzymes. All strains significantly reduced the growth of studied fungi and the bacterial cells were more bioactive than bacterial filtrates. All tested Bulkholderia strains produced volatile organic compounds (VOCs), which inhibited the fungal growth and reduced the growth rate of Fusarium oxysporum and Rhizoctonia solani. GC/MS analysis of VOCs emitted by strain Bga 11096 indicated the presence of a compound that was identified as 1-methyl-4-(1-methylethenyl)-cyclohexene, a liquid hydrocarbon classified as cyclic terpene. This compound could be responsible for the antifungal activity, which is also in agreement with the work of other authors.

Chemical Composition and Biological Activity of the Essential Oil of Origanum vulgare ssp. hirtum from Different Areas in the Southern Apennines (Italy)

The chemical composition of the essential oils of Origanum vulgare ssp. hirtum, growing wild in three different localities in the Southern Apennines, was studied by GC‐FID and GC/MS analyses. In total, 103 compounds were identified. The oils were mainly composed of phenolic compounds and all oils belonged to the chemotype carvacrol/thymol. The three essential oils were evaluated for their in vitro phytotoxic activity by determining their influence on the germination and initial radicle elongation of Sinapis arvensis L., Phalaris canariensis L., Lepidium sativum L., and Raphanus sativus L. The seed germination and radicle growth were affected in various degrees. Moreover, the antifungal activity of the three essential oils was assayed against three species causing pre‐ and postharvest fruit decay (Monilinia laxa, M. fructigena, and M. fructicola). At 1000 ppm, the three oils completely inhibited fungal growth. The hemolytic activity of the oils was assayed and showed no effect on the cell membranes of bovine erythrocytes.

An In Vitro Attempt for Controlling Severe Phytopathogens and Human Pathogens Using Essential Oils from Mediterranean Plants of Genus Schinus

Growing concerns about food safety and environmental protection enhanced the need for new and safe plant disease control strategies. The chemical composition of the three essential oils (EOs) extracted from leaves and fruits of Schinus terebinthifolius and leaves of Schinus molle, growing in Tunisia, was studied by GC and GC-MS. In all, 12 compounds were identified. The oils were mainly composed of terpene compounds. α-Pinene, α-phellandrene, and D-limonene were the major constituents. The aim of the current study was to evaluate the in vitro antimicrobial effectiveness of three EOs derived from plants of genus Schinus and extracted from leaves and fruits of S. terebinthifolius and leaves of S. molle. Both antifungal and antibacterial activities of the EOs were examined. The antifungal activity of the studied EOs was investigated against Colletotrichum acutatum and Botrytis cinerea in comparison with the systemic fungicide azoxystrobin used at 0.8 μL mL(-1). The antibacterial activity was evaluated against three strains of Gram-positive (G+ve) bacteria (Bacillus megaterium, Bacillus mojavensis and Clavibacter michiganensis) and four strains of Gram-negative (G-ve) bacteria (Escherichia coli, Xanthomonas campestris, Pseudomonas savastanoi, and Pseudomonas syringae pv. phaseolicola) compared with the synthetic antibiotic tetracycline at a concentration of 1600 μg mL(-1). The minimum inhibitory concentration of the studied EOs has been evaluated against the above microorganisms using the 96-well microplate method. Tested microorganisms exhibited different levels of sensitivity to each tested EO. All investigated EOs reduced the fungal mycelial growth when used at low concentrations from 250 to 1000 ppm and from 2000 to 8000 ppm against C. acutatum and B. cinerea, respectively. Higher concentrations of the same EOs exhibited a fungicidal effect against both mitosporic fungi. The EO extracted from leaves of S. terebinthifolius significantly inhibited the growth of tested bacterial strains. Nevertheless, E. coli showed a weak resistance toward the same EO and a high resistance toward the other two tested EOs. Finally, P. savastanoi and P. syringae pv. phaseolicola showed a high resistance toward all tested EOs.

Cytotoxic Activity of Origanum Vulgare L. on Hepatocellular Carcinoma cell Line HepG2 and Evaluation of its Biological Activity

The potential of plant essential oils (EOs) in anticancer treatment has recently received many research efforts to overcome the development of multidrug resistance and their negative side effects. The aims of the current research are to study (i) the cytotoxic effect of the crude EO extracted from Origanum vulgare subsp hirtum and its main constituents (carvacrol, thymol, citral and limonene) on hepatocarcinoma HepG2 and healthy human renal cells HEK293; (ii) the antibacterial and phytotoxic activities of the above EO and its main constituents. Results showed that cell viability percentage of treated HepG2 by EO and its main constituents was significantly decreased when compared to untreated cells. The calculated inhibition concentration (IC50) values for HepG2 were lower than healthy renal cells, indicating the sort of selectivity of the studied substances. Citral is not potentially recommended as an anticancer therapeutic agent, since there are no significant differences between IC50 values against both tested cell lines. Results showed also that oregano EO and its main constituents have a significant antibacterial activity and a moderate phytotoxic effect. The current research verified that oregano EO and its main constituents could be potentially utilized as anticancer therapeutic agents.

Diversity Evaluation of Xylella fastidiosa from Infected Olive Trees in Apulia (Southern Italy).

Olive culture is very important in the Mediterranean Basin. A severe outbreak of Olive Quick Decline Syndrome (OQDS) caused by Xylella fastidiosa infection was first noticed in 2013 on olive trees in the southern part of Apulia region (Lecce province, southern Italy). Studies were carried out for detection and diversity evaluation of the Apulian strain of Xylella fastidiosa. The presence of the pathogen in olive samples was detected by PCR amplifying the 16S rDNA, gyrase B subunit (gyrB) and HL hypothetical protein genes and single nucleotide polymorphisms (SNPs) assessment was performed to genotype X. fastidiosa. Twelve SNPs were recorded over gyrB and six SNPs were found for HL gene. Less variations were detected on 16S rDNA gene. Only gyrB and HL provided sufficient information for dividing the Apulian X. fastidiosa olive strains into subspecies. Using HL nucleotide sequences was possible to separate X. fastidiosa into subspecies pauca and fastidiosa. Whereas, nucleotide variation present on gyrB gene allowed separation of X. fastidiosa subsp. pauca from the other subspecies multiplex and fastidiosa. The X. fastidiosa strain from Apulia region was included into the subspecies pauca based on three genes phylogenetic analyses.

Effects of different heat treatments on lysozyme quantity and antimicrobial activity of jenny milk

Thermal treatments are used to improve milk microbial safety, shelf life, and biological activity of some of its components. However, thermal treatments can reduce the nutritional quality of milk, affecting the molecular structure of milk proteins, such as lysozyme, which is a very important milk component due to its antimicrobial effect against gram-positive bacteria. Jenny milk is characterized by high lysozyme content. For this reason, in the last few years, it has been used as an antimicrobial additive in dairy products as an alternative to hen egg white lysozyme, which can cause allergic reactions. This study aimed to investigate the effect of pasteurization and condensation on the concentration and antimicrobial activity of lysozyme in jenny milk. Furthermore, lysozyme quantity and activity were tested in raw and pasteurized milk after condensation at 40 and 20% of the initial volume. Reversed-phase HPLC was performed under fluorescence detection to monitor lysozyme in milk samples. We evaluated the antimicrobial activity of the tested milk against Bacillus megaterium, Bacillus mojavensis, Clavibacter michiganensis, Clostridium tyrobutyricum, Xanthomonas campestris, and Escherichia coli. Condensation and pasteurization did not affect the concentration or antimicrobial activity of lysozyme in jenny milk, except for B. mojaventis, which showed resistance to lysozyme in milk samples subjected to heat treatments. Moreover, lysozyme in jenny milk showed antimicrobial activity similar to synthetic antibiotics versus some gram-positive strains and also versus the gram-negative strain X. campestris.

Effect of irrigation regimes and artificial mycorrhization on insect pest infestations and yield in tomato crop

A 2-year field experiment was carried out to test the effect of root symbionts treatments in combination with different watering levels on tomato yield and pest infestation rates. A split-plot experimental design was followed, where the main treatments were three irrigation regimes, and the subplot factor was the mycorrhizal treatment (two mycorrhizal treatments [M1 and M2] and the control). The M1 treatment consisted in the use of a commercial preparation (Micosat F; CCS Aosta, Italy) containing a mixture of vesicular-arbuscular mycorrhizae (VAM), bacteria of the rhizosphere and saprophytic fungi, while M2 treatment used only arbuscular mycorrhizal fungi. Insect pests sampled in the field during the 2 years of experiment were all sap-feeders (Trialeurodes vaporariorum, Macrosiphum euphorbiae, Frankliniella occidentalis and an unidentified species of leafhopper). Results did not show any impact of root symbionts on pests, whereas water deficit significantly reduced plant infestation rates. Both mycorrhization treatments and water supply resulted in a significantly positive effect on crop yield.

Detection of Syringomycin in Plant Tissues Infected with Pseudomonas syringae pv. syringae

Syringomycin, a phytotoxic and antifungal Itpodepsipeptide produced by most strains of Pseudomonas syringae pv. syringae was isolated from etiolated bean cotyledons artificially inoculated with the millet strain B359 of the pathogen and identified by FAB-MS. The results provide the first evidence of the presence of this Phytotoxin in the diseased tissue. These finding supports its role in pathogenesis.