Penicillium Oxalicum Strain Research Articles

Development of a Method for Detection of the Biocontrol Agent Penicillium oxalicum Strain 212 by Combining PCR and a Selective Medium.

The registration of biological control agents requires the development of monitoring systems to detect and quantify the agent in the environment. Penicillium oxalicum strain 212 (PO212) is being developed for the control of tomato pathogens. In this study, we demonstrated that PO212 was more effective for controlling Fusarium oxysporum f. sp. lycopersici in tomato plants than 13 other P. oxalicum strains. A new semiselective medium was developed as a preliminary screen for P. oxalicum from soil. This semiselective medium was a modified Fusarium selective medium that contained 0.006 g of nystatin per liter. The growth of P. oxalicum strain 212 was not inhibited on this medium, but it did inhibit the growth of 11 fungal species. Specific identification of the biocontrol strain and its quantification were achieved using a polymerase chain reaction with a strain-specific pair of primers (POITS1F/POITS2R1) and dilution plating. This primer set differentiated the biocontrol strain from 13 other strains of P. oxalicum. There were differences in the nucleotide sequences of the internal transcribed spacer (ITS) regions of the ribosomal DNA of 25 strains of P. oxalicum and those of PO212. Based on the differences in the nucleotide sequences of the ITS regions in rDNA of PO212 and other P. oxalicum strains, a relationship between the nucleotide sequences in the ITS region and biocontrol efficacy is postulated.

Antifungal substances produced by Penicillium oxalicum strain PY-1—potential antibiotics against plant pathogenic fungi

This paper reports the isolation from soil of Penicillium strain PY-1 with strong antagonistic activity against plant pathogenic fungi. On the basis of its morphological characteristics and the sequence of the ITS region, strain PY-1 was identified as P. oxalicum. Strain PY-1 produces antifungal substances that suppress the mycelial growth of Sclerotinia sclerotiorum and many other plant pathogenic fungi tested; the highest antagonistic activity was detected at 72 h when cultured in a 250-ml flask containing 80 ml potato dextrose broth. Compared with carbendazim, the relative activity of the antifungal substances produced by strain PY-1 was approximately 4 μg active ingredient (a.i.) per milliliter. The antifungal substances were extracted with ethyl acetate and further separated by high-performance liquid chromatography (HPLC); at least two active components were discovered. The ability to control plant disease with strain PY-1 was confirmed with S. sclerotiorum, a widespread pathogenic fungus that attacks rapeseed (Brassica napus) and other plants. Spores (106 or 107 ml−1) and filtrate (tenfold diluted or undiluted) of strain PY-1 could significantly suppress infection and/or the extent of infection by S. sclerotiorum of plants at seven-true-leaves stage. The potential of strain PY-1 for identifying new antibiotics to control fungal disease and for biological control of plant disease, for example oilseed rape stem rot, is discussed.

A metal-independent hydrolase from a Penicillium oxalicum strain able to use phosphonoacetic acid as the only phosphorus source

A Penicillium oxalicum strain was capable of the phosphate-sensitive utilization of phosphonoacetic acid as the sole source of phosphorus. A carbon-to-phosphorus bond-cleavage enzyme yielding acetic acid and inorganic phosphate was detected and characterized in extracts from cells grown on this phosphonate. Contrary to bacterial phosphonoacetate hydrolases, the fungal enzyme neither required nor was stimulated by divalent cations.