The production of lipase by twenty-nine yeasts isolated from the phylloplane of Hibiscus rosa-sinensis was evaluated. The highest lipase producers were Pseudozyma hubeiensis HB85A, Debaryomyces occidentalis-like HB83 and Cryptococcus sp. HB80. P. hubeiensis HB85A batch fermentations were carried out in a bioreactor and lipase production improved 3.2-fold as compared to flask submerged cultures. The production process was significantly reduced from 48 h (in flasks) to 18 h (in the bioreactor). The better hydrolytic activity was achieved with C16 p-nitrophenyl ester. Maximal activity was observed at pH 7.0, the optimum temperature was 50 degrees C at pH 7.0 and the enzyme was stable at 30 and 40 degrees C. The lipolytic activity was stimulated by Mg(2+), K(+) and Ba(2+) salts and EDTA and slightly inhibited by Ca(2+) salts. Non-ionic detergents such as Triton X-100, Tween 80 and Tween 20 strongly stimulated lipase activity, whereas SDS inhibited it. The lipase was stable in iso-octane and hexane at 80%.

BackgroundMetarhizium anisopliae is an entomopathogenic fungus used in the biological control of some agricultural insect pests, and efforts are underway to use this fungus in the control of insect-borne human diseases. A large repertoire of proteins must be secreted by M. anisopliae to cope with the various available nutrients as this fungus switches through different lifestyles, i.e., from a saprophytic, to an infectious, to a plant endophytic stage. To further evaluate the predicted secretome of M. anisopliae, we employed genomic and transcriptomic analyses, coupled with phylogenomic analysis, focusing on the identification and characterization of secreted proteins.ResultsWe determined the M. anisopliae E6 genome sequence and compared this sequence to other entomopathogenic fungi genomes. A robust pipeline was generated to evaluate the predicted secretomes of M. anisopliae and 15 other filamentous fungi, leading to the identification of a core of secreted proteins. Transcriptomic analysis using the tick Rhipicephalus microplus cuticle as an infection model during two periods of infection (48 and 144 h) allowed the identification of several differentially expressed genes. This analysis concluded that a large proportion of the predicted secretome coding genes contained altered transcript levels in the conditions analyzed in this study. In addition, some specific secreted proteins from Metarhizium have an evolutionary history similar to orthologs found in Beauveria/Cordyceps. This similarity suggests that a set of secreted proteins has evolved to participate in entomopathogenicity.ConclusionsThe data presented represents an important step to the characterization of the role of secreted proteins in the virulence and pathogenicity of M. anisopliae.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2164-15-822) contains supplementary material, which is available to authorized users.

Abstract. Zygomycosis is an important granulomatous disease that affects humans and animals, particularly sheep in tropical regions. Rhinofacial and nasopharyngeal zygomycosis were described in sheep in association with Conidiobolus spp. The present study characterized 5 samples of Conidiobolus isolated from 3 herds with clinical disease in Mato Grosso State, Brazil. The clinical and pathological findings were similar to nasopharyngeal zygomycosis. Based on morphological features, isolates were classified as Conidiobolus spp., and molecular phylogenetic analyses based on 18S ribosomal DNA grouped all isolates in a Conidiobolus lamprauges cluster. The current report describes the molecular characterization of ovine nasopharyngeal zygomycosis associated with C. lamprauges.

Metarhizium anisopliae is an entomopathogenic fungus with the ability to infect a broad range of arthropods, and have evolved distinct strategies for their attachment to hosts. Here, we describe the characterisation of ecto-phosphatase activity on the conidia surface of M. anisopliae and its relevance in the host interaction process. Ecto-phosphatase activity was linear for 60 min and during this time, was linear with the increase of cell density. The optimum pH was in the acidic range and some divalent metals, such as Cu(2+), Cd(2+) and Zn(2+), inhibited ecto-phosphatase activity. The activity was also reduced by phosphatase inhibitors. Importantly, the inhibition of phosphatase activity in conidia reduced the adhesion to Dysdercus peruvianus (Hemiptera: Pyrrhocoridae) integument and, consequently and indirectly, M. anisopliae infection. The results herein presented show, for the first time, the importance of ecto-phosphatase activity in M. anisopliae conidia and provide the first evidence of its direct involvement in adhesion and host infection.