Improvement of cordycepin production by an isolated Paecilomyces hepiali mutant from combinatorial mutation breeding and medium screening.

Cordycepin is a major bioactive compound found in Cordyceps sinensis that exhibits a broad spectrum of biological activities. Here a Paecilomyces hepiali OR-1 strain was initially isolated from plateau soil for the bioproduction of cordycepin. Subsequently, strain modification including 60Co γ-ray and ultraviolet irradiation were employed to increase the cordycepin titer, resulted in a high-yield mutant strain P. hepiali ZJB18001 with the cordycepin content of 0.61 mg/gDCW, showing a 2.3-fold to that from the wild strain (0.26 mg/gDCW). Furthermore, medium screening based on Box-Behnken design and the response surface methodology facilitated the enhancement of cordycepin yield to the value of 0.96 mg/gDCW at 25 °C for 5 days in submerged cultivation with an optimized medium composition. The high cordycepin yield, rapid growth rate and stable genetic characteristics of P. hepiali ZJB18001 are beneficial in terms of costs and time for the industrialization of cordycepin production.

Secondary Metabolites and Their Bioactivities Produced by Paecilomyces.

Paecilomyces, a common saprobic filamentous fungus, not only plays an important role in biological control, but also has applications in medicine, food, and environmental protection. In this paper, 223 secondary metabolites and their bioactivities from 13 known species and various unidentified strains of Paecilomyces are reviewed. Their structures can be described as polyketide, terpenoid, peptide, alkaloid, quinone, pyrone, sterol, and fatty acid. They have been demonstrated varying biological activities, including antimicrobial, antitumor, insecticidal, antiplasmodial, antimalarial, nematicidal, herbicidal, and enzyme-inhibiting. This review provides a comprehensive overview of secondary metabolites and their biological activities from strains of Paecilomyces.

Identification of hypocrealean reptile pathogenic isolates with MALDI-TOF MS.

Biotyper analysis of Nannizziopsis guarroi, a fatal fungal pathogen in lizards, was described recently. Hypocrealean fungal infections in captive reptiles appear with an increasing frequency during the last decade. Therefore, the aim of this study was to proof Matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) as diagnostic tool for the identification of reptile pathogenic hypocrealean fungi. Ten fungal isolates obtained from nine reptiles with fungal glossitis, disseminated visceral mycosis, pneumomycosis, and fungal keratitis were analyzed. Phylogeny consisted of fragments of the large subunit of nuclear encoded ribosomal DNA (D1/D2, LSU) and the internal transcribed spacer region 1 of nuclear encoded ribosomal DNA (ITS1) as well as the protein coding gene translation elongation factor 1 alpha (TEF). Results revealed unanimously two Metarhizium granulomatis genotypes in a total of three isolates, various M. viride genotypes (n = 3), two different Purpureocillium lilacinum isolates as well as one isolate of each P. lavendulum and Beauveria bassiana. Purpureocillium lilacinum and B. bassiana are likewise frequently employed as a mycoinsecticide and mycoacaricide in agriculture on a worldwide scale and have occasionally been reported in man, causing fungal keratitis, sclerokeratitis, nosocomial infections in immunosuppressed patients, as well as cavitary pulmonary disease and cutaneous hyalohyphomycosis in immunocompetent patients. According to the results establishment of Biotyper analysis for faster differentiation of reptile-associated fungal pathogens is entirely justified.

Paecilomyces Rot: A New Apple Disease.

Paecilomyces niveus is an important food spoilage fungus that survives thermal processing in fruit products, where it produces the mycotoxin patulin. Spoilage of products has been attributed to soil contamination; however, little is known about the ecology of this organism. In this study, orchard soils and culled apple fruit were surveyed and the ability of P. niveus to infect apple was tested on two popular apple varieties. P. niveus was found in 34% of sampled orchard soils from across New York. Completing Koch's postulates, P. niveus was demonstrated to cause postharvest disease in Gala and Golden Delicious apple. Symptoms of this disease, named Paecilomyces rot, resemble several other apple diseases, including black rot, bitter rot, and bull's-eye rot. External symptoms of Paecilomyces rot include brown, circular, concentrically ringed lesions, with an internal rot that is firm and cone-shaped. Both Gala and Golden Delicious apple fruit inoculated with P. niveus developed lesions ≥43 mm in size at 22 days after inoculation. There is some evidence that the size of lesions and rate of infection differ between Gala and Golden Delicious, which may indicate differing resistance to P. niveus. This work shows that P. niveus is common in New York orchard soil and can cause a novel postharvest fruit disease. Whether infected fruit can serve as an overlooked source of inoculum in heat-processed apple products requires further study.

[Discussion on related problems of model species of fungus： Paecilomyces hepialid].

Paecilomyces hepiali is a new species of fungus isolated from a field collection of Ophiocordyceps sinensis from Baima snow mountain, Diqing Tibetan Autonomous Prefecture, Yunnan Province by the Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences. The specimen was identified and named as Paecilomyces hepiali by Qing-Tao Chen, the professor of the Institute of Microbiology, Chinese Academy of Sciences (Paecilomyces hepiali) (2008), who identified a dried culture of living strain 82-2 as the holotype. Until now, the holotype (the voucher specimen) was deposited in the Herbarium of the Institute of Chinese Materia Medica (HICMM), China Academy of Chinese Medical Sciences, Beijing. The P. hepiali neotype designated by the paper "Neotypification of P. hepiali (Hypocreales)" published in TAXON 64 (1) by Yao Yi-Jian et al. in February 2015 is untenable.

Paecilomyces niveus Stolk & Samson, 1971 (Ascomycota: Thermoascaceae) as a pathogen of Nasonovia ribisnigri (Mosley, 1841) (Hemiptera, Aphididae) in Brazil.

Nasonovia ribisnigri is a key pest of lettuce (Lactuca sativa L.) in Brazil that requires alternative control methods to synthetic pesticides. We report, for the first time, the occurrence of Paecilomyces niveus as an entomopathogen of the aphid Nasonovia ribisnigri in Pinhais, Paraná, Brazil. Samples of mummified aphids were collected from lettuce crops. The fungus P. niveus (PaePR) was isolated from the insect bodies and identified by macro and micromorphology. The species was confirmed by sequencing Internal Transcribed Spacer (ITS) rDNA. We obtained a sequence of 528 bp (accession number HQ441751), which aligned with Byssochlamys nivea strains (100% identities). In a bioassay, 120 h after inoculation of N. ribisnigri with pathogenic P. niveus had an average mortality of 74%. The presence of P. niveus as a natural pathogen of N. ribisnigri in Brazil suggests that it may be possible to employ P. niveus to minimize the use of chemical insecticides.

Paecilomyces niveus Stolk & Samson, 1971 (Ascomycota: Thermoascaceae) as a pathogen of Nasonovia ribisnigri (Mosley, 1841) (Hemiptera, Aphididae) in Brazil / Registro de Paecilomyces niveus Stolk & Samson, 1971 (Ascomycota: Thermoascaceae) como patógeno de Nasonovia ribisnigri (Mosley, 1841) (Hemiptera, Aphididae) no Brasil

Abstract Nasonovia ribisnigri is a key pest of lettuce (Lactuca sativa L.) in Brazil that requires alternative control methods to synthetic pesticides. We report, for the first time, the occurrence of Paecilomyces niveus as an entomopathogen of the aphid Nasonovia ribisnigri in Pinhais, Paraná, Brazil. Samples of mummified aphids were collected from lettuce crops. The fungus P. niveus (PaePR) was isolated from the insect bodies and identified by macro and micromorphology. The species was confirmed by sequencing Internal Transcribed Spacer (ITS) rDNA. We obtained a sequence of 528 bp (accession number HQ441751), which aligned with Byssochlamys nivea strains (100% identities). In a bioassay, 120 h after inoculation of N. ribisnigri with pathogenic P. niveus had an average mortality of 74%. The presence of P. niveus as a natural pathogen of N. ribisnigri in Brazil suggests that it may be possible to employ P. niveus to minimize the use of chemical insecticides.

Resumo Nasonovia ribisnigri é uma praga-chave do cultivo de alface (Lactuca sativa L.), exigindo métodos alternativos ao controle químico. Este trabalho registrou pela primeira vez, a ocorrência de Paecilomyces niveus como agente entomopatogenico do afídeo N. ribisnigri em Pinhais, Paraná, Brasil. Amostras de afídeos mumificados foram coletadas em plantas de alface. O fungo P. niveus (PaePR) foi isolado do corpo dos insetos e identificado por macro e micromorfologia e, confirmado por sequenciamento da região ITS do DNA ribossomal. A sequencia parcial de 528 bp (número de acesso HQ441751) apresentou alinhamento com 100% de identidade com sequencias de raças de Byssochlamys nivea. No bioensaio de patogenicidade P. niveus apresentou uma mortalidade média de N. ribisnigri de 74% até 120 horas da inoculação. O registro da presença de P. niveus como um patógeno natural de N. ribisnigri no Brasil sugere o potencial de utilização para minimizar o uso de inseticidas.

Triazole Susceptibilities in Thermotolerant Fungal Isolates from Outdoor Air in the Seoul Capital Area in South Korea.

Emerging fungi resistant to triazoles are a concern because of the increased use of medical triazoles and exposure to agricultural triazoles. However, little is known about the levels of triazole susceptibility in outdoor airborne fungi making it difficult to assess the risks of inhalation exposure to airborne, antifungal-resistant fungi. This study examined triazole susceptibilities of the airborne thermotolerant fungi isolated from the ambient air of the Seoul Capital Area of South Korea. We used impactor air sampling with triazole-containing nutrient agar plates as the collection substrates to screen for airborne fungal isolates based on their triazole susceptibilities. This study estimated that 0.17% of all the culturable fungi belong to the pathogenic thermotolerant taxa, among which each isolate of Aspergillus niger and Aspergillus tubingensis showed a minimum inhibitory concentration (MIC) of 2 µg/mL or greater for itraconazole. Their concentration in air was 0.4 CFU/m3. Seven human pathogenic Paecilomyces variotii isolates had MICs of 32 µg/mL or greater and lower than 2 µg/mL for the agricultural fungicide tebuconazole and the medical triazole itraconazole, respectively. Though the concentration was low, our results confirm the presence of airborne fungi with high MICs for itraconazole in ambient air. Inhalation is an important exposure route because people inhale more than 10 m3 of air each day. Vigilance is preferred over monitoring for the emergence of triazole-resistant fungal pathogens in ambient outdoor air.

The role of a phospholipase (PLD) in virulence of Purpureocillium lilacinum (Paecilomyces lilacinum).

Phospholipases are key enzymes in pathogenic fungi that cleave host phospholipids, resulting in membrane destabilization and host cell penetration. However, understanding the role of phospholipases on the virulence of the filamentous fungus Purpureocillium lilacinum has been still rather limited. In this study, pld gene was characterized. It encodes the protein phospholipase D (PLD) in P. lilacinum. This gene, 3303 bp open reading frame fragment (ORF), encodes a protein of 1100 amino acids with high similarity to the same gene from Penicillium oxalicum and Aspergillus fumigatus. Secondary structure prediction showed two PLD phosphodiesterase domains (437-464 bp and 885-912 bp). The pld gene was significantly regulated during infection of Meloidogyne incognita eggs by P. lilacinum. The expression of pld gene using RT-PCR was the highest at 36 and 48 h, which introduce evidence that the presence of M. incognita may induce the expression of the pld gene in P. lilacinum. In addition, maltose and l-alanine were found to increase the expression of pld gene. An acidic environment (pH 3.0-4.0) and moderate temperatures (27-29 °C) are favorable for pld expression in P. lilacinum.

Complexities associated with the molecular and proteomic identification of Paecilomyces species in the clinical mycology laboratory.

Paecilomyces species are emerging fungal pathogens. Morphological identifications are complicated by similarities among the members of the P. variotii complex as well as to some Rasamsonia and Hamigera species. The purpose of this study was to compare matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) with molecular diagnostic standards (i.e., multilocus DNA sequencing of the internal transcribed spacer regions 1 and 2, D1/D2 regions, and part of the ß-tubulin gene) for the identification of Paecilomyces spp. encountered in two clinical mycology laboratories. A total of 77 clinical isolates identified morphologically as P. variotii (n = 21), P. lilacinus (n = 52), and Paecilomyces spp. not otherwise specified (n = 4) were included. In accord with the most recent taxonomy, all P. lilacinus isolates were confirmed as Purpureocillium lilacinum by both sequencing and MALDI-TOF MS. Fungi phenotypically resembling P. variotii or Paecilomyces spp. were identified by molecular techniques as P. variotii sensu stricto (n = 12), P. formosus (n = 3), P. dactylethromorphus (n = 3), Rasamsonia argillacea (n = 4), or R. piperina (n = 1) and at the genus level as an isolate of a Hamigera sp. and a Paecilomyces sp. There was 92.2% (71/77) agreement between the molecular and proteomic methods only after supplementation of the MALDI-TOF MS database with type strains. Paecilomyces variotii-like organisms required multilocus DNA interrogations for differentiation and account for all of the fungi whose identification was missed by MALDI-TOF MS. Overall, MALDI-TOF MS was a rapid and reliable alternative to multilocus sequencing. However, significant augmentation of the commercially available database was required to reproducibly identify this group of important human pathogens.

Multiple gene genealogical analyses of a nematophagous fungus Paecilomyces lilacinus from China.

Paecilomyces lilacinus is a geographically widespread nematophagous fungus and a promising biological control agent against plant parasitic nematodes. However, relatively little is known about its patterns of genetic variation through its broad geographic and ecological contexts. In this study, we analyzed the genetic variation of 2 virulence-associated genes (PLS and PLC) and 4 housekeeping gene fragments (ITS, RPB1, RPB2, and ß-tubulin) among 80 P. lilacinus specimens collected from 7 locations in China. Various degrees of polymorphism and haplotype diversity were observed among the six gene fragments. However, no genetic differentiation was observed among the geographic populations, consistent with extensive gene flow among these geographic populations of P. lilacinus in China. Our analysis also suggested that clonal reproduction was the predominant mode of reproduction in natural populations of P. lilacinus.

Abundance and dynamics of filamentous fungi in the complex ambrosia gardens of the primitively eusocial beetle Xyleborinus saxesenii Ratzeburg (Coleoptera: Curculionidae, Scolytinae).

Insect fungus gardens consist of a community of interacting microorganisms that can have either beneficial or detrimental effects to the farmers. In contrast to fungus-farming ants and termites, the fungal communities of ambrosia beetles and the effects of particular fungal species on the farmers are largely unknown. Here, we used a laboratory rearing technique for studying the filamentous fungal garden community of the ambrosia beetle, Xyleborinus saxesenii, which cultivates fungi in tunnels excavated within dead trees. Raffaelea sulfurea and Fusicolla acetilerea were transmitted in spore-carrying organs by gallery founding females and established first in new gardens. Raffaelea sulfurea had positive effects on egg-laying and larval numbers. Over time, four other fungal species emerged in the gardens. Prevalence of one of them, Paecilomyces variotii, correlated negatively with larval numbers and can be harmful to adults by forming biofilms on their bodies. It also comprised the main portion of garden material removed from galleries by adults. Our data suggest that two mutualistic, several commensalistic and one to two pathogenic filamentous fungi are associated with X. saxesenii. Fungal diversity in gardens of ambrosia beetles appears to be much lower than that in gardens of fungus-culturing ants, which seems to result from essential differences in substrates and behaviours.

Endophytic fungal association via gibberellins and indole acetic acid can improve plant growth under abiotic stress: an example of Paecilomyces formosus LHL10.

BACKGROUND: Endophytic fungi are little known for exogenous secretion of phytohormones and mitigation of salinity stress, which is a major limiting factor for agriculture production worldwide. Current study was designed to isolate phytohormone producing endophytic fungus from the roots of cucumber plant and identify its role in plant growth and stress tolerance under saline conditions. RESULTS: We isolated nine endophytic fungi from the roots of cucumber plant and screened their culture filtrates (CF) on gibberellins (GAs) deficient mutant rice cultivar Waito-C and normal GAs biosynthesis rice cultivar Dongjin-byeo. The CF of a fungal isolate CSH-6H significantly increased the growth of Waito-C and Dongjin-byeo seedlings as compared to control. Analysis of the CF showed presence of GAs (GA1, GA3, GA4, GA8, GA9, GA12, GA20 and GA24) and indole acetic acid. The endophyte CSH-6H was identified as a strain of Paecilomyces formosus LHL10 on the basis of phylogenetic analysis of ITS sequence similarity. Under salinity stress, P. formosus inoculation significantly enhanced cucumber shoot length and allied growth characteristics as compared to non-inoculated control plants. The hypha of P. formosus was also observed in the cortical and pericycle regions of the host-plant roots and was successfully re-isolated using PCR techniques. P. formosus association counteracted the adverse effects of salinity by accumulating proline and antioxidants and maintaining plant water potential. Thus the electrolytic leakage and membrane damage to the cucumber plants was reduced in the association of endophyte. Reduced content of stress responsive abscisic acid suggest lesser stress convened to endophyte-associated plants. On contrary, elevated endogenous GAs (GA3, GA4, GA12 and GA20) contents in endophyte-associated cucumber plants evidenced salinity stress modulation. CONCLUSION: The results reveal that mutualistic interactions of phytohormones secreting endophytic fungi can ameliorate host plant growth and alleviate adverse effects of salt stress. Such fungal strain could be used for further field trials to improve agricultural productivity under saline conditions.

Purpureocillium, a new genus for the medically important Paecilomyces lilacinus.

Paecilomyces lilacinus was described more than a century ago and is a commonly occurring fungus in soil. However, in the last decade this fungus has been increasingly found as the causal agent of infections in man and other vertebrates. Most cases of disease are described from patients with compromised immune systems or intraocular lens implants. In this study, we compared clinical isolates with strains isolated from soil, insects and nematodes using 18S rRNA gene, internal transcribed spacer (ITS) and partial translation elongation factor 1-α (TEF) sequences. Our data show that P. lilacinus is not related to Paecilomyces, represented by the well-known thermophilic and often pathogenic Paecilomyces variotii. The new genus name Purpureocillium is proposed for P. lilacinus and the new combination Purpureocillium lilacinum is made here. Furthermore, the examined Purpureocillium lilacinum isolated grouped in two clades based on ITS and partial TEF sequences. The ITS and TEF sequences of the Purpureocillium lilacinum isolates used for biocontrol of nematode pests are identical to those causing infections in (immunocompromised) humans. The use of high concentrations of Purpureocillium lilacinum spores for biocontrol poses a health risk in immunocompromised humans and more research is needed to determine the pathogenicity factors of Purpureocillium lilacinum.

Characterization of a hydrophobin of the ascomycete Paecilomyces farinosus.

The entomopathogenic ascomycete Paecilomyces farinosus (alternative name Isaria farinosa) synthesized a hydrophobin, irrespective of being grown in submerged or surface culture. The protein was extracted using trifluoroacetic acid and purified using preparative HPLC and SDS-PAGE. Partial sequences were obtained using ESI-MS/MS. The peptides were used as a start to apply a 'template switching oligo' protocol to elucidate the complete open reading frame of P. farinosus hydrophobin 1 (pfah1). The deduced protein sequence comprised 107 amino acids (10.7 kDa) including a 16 amino acid long hydrophobic signal peptide, showed a calculated pI of 4.56, and was interrupted by one intron. Phylogenetic analyses revealed relationships to hydrophobins of the ascomycetes Magnaporthe grisea and Metarhizium anisopliae. Based on solubility, hydropathy pattern and phylogeny PfaH1 was assigned to the class Ia hydrophobins.

Effect of Meloidogyne incognita inoculum density and application rate of Paecilomyces lilacinus strain 251 on biocontrol efficacy and colonization of egg masses analyzed by real-time quantitative PCR.

The fungal biocontrol agent, Paecilomyces lilacinus strain 251 (PL251), was evaluated for its potential to control the root-knot nematode Meloidogyne incognita on tomato at varying application rates and inoculum densities. Conversely to previous studies, significant dose-response relationships could not be established. However, we demonstrated that a preplanting soil treatment with the lowest dose of commercially formulated PL251 (2 × 10(5) CFU/g soil) was already sufficient to reduce root galling by 45% and number of egg masses by 69% when averaged over inoculum densities of 100 to 1,600 eggs and infective juveniles per 100 cm(3) of soil. To determine the role of colonization of M. incognita egg masses by PL251 for biocontrol efficacy, a real-time quantitative polymerase chain reaction (PCR) assay with a detection limit of 10 CFU/egg mass was used. Real-time PCR revealed a significant relationship between egg mass colonization by PL251 and the dose of product applied to soil but no correlation was found between fungal density and biocontrol efficacy or nematode inoculum level. These results demonstrate that rhizosphere competence is not the key mode of action for PL251 in controlling M. incognita on tomato.

Synchronous infection with Mycobacterium chelonae and Paecilomyces in a heart transplant patient.

A 41-year-old male who was 3 years status post heart transplant presented with a 3-month history of painful erythematous nodules and ulcers on his lower legs and right hand. First, Mycobacterium chelonae infection was revealed through several biopsies with molecular sequence analysis, and combination treatment, including clarithromycin, was started. During the treatment, lesions of the legs showed an improvement, but a fluctuant erythematous nodule on the thumb did not respond. Repetitive biopsy from the thumb ultimately identified Paecilomyces species and the patient was treated with itraconazole and terbinafine sequentially. Our case is the first report, to our knowledge, of synchronous infection with non-tuberculous mycobacteria (NTM) and Paecilomyces in a solid organ transplant recipient. Our findings highlight the importance of recognizing cutaneous NTM infections or deep mycoses, as well as the importance of choosing an appropriate treatment.

[Improvement of catalytic capability of Paecilomyces thermophila J18 thermostable beta-1,3-1,4-glucanase under acidic condition by directed evolution].

Directed evolution was used to improve the performance of beta-1,3-1,4-glucanase (designated as PtLicl6A) from Paecilomyces thermophila J18 under acidic condition. A mutant library was constructed by error-prone PCR and DNA shuffling, and positive clones were screened by Congo red staining. More than 1 500 mutants were selected. One mutant (PtLic16AM1) exhibited an optimal activity at pH 5.5, while the optimal pH of the wild-type enzyme was 7.0. The mutant PtLic16AM1 kept the high specific activity and thermotolerence of the wild-type enzyme. Sequence analysis revealed that the mutant enzyme has four sense substitutions which caused four amino acid substitutions - namely T58S, Y110N, G195E and D221G.. Homology modeling showed that among the four amino acid substitutions, Y110N was near the active site of the enzyme, while the other three was distant. T58S and G195E may play key roles in the change of optimal pH. This study provided a new perspective of obtaining applicable 3-1,3-1,4-glucanase for industrial use.

Fungal endophthalmitis caused by Paecilomyces variotii, in an immunocompetent patient, following intraocular lens implantation.

We report the case of a 70-year-old man who was admitted for anterior endophthalmitis following an intraocular lens implantation. He had developed a fluffy growth resembling a fungal mass on the iris of the right eye. The mass was removed and sent for fungal studies to our department. Direct microscopy revealed hyphae. Further studies helped identify the fungus to belong to genus Paecilomyces. This is a rare case of fungal endophthalmitis caused by Paecilomyces variotii in an immunocompetent person.