Search

During a survey of fungal diversity in a deserted rocky area in Yunnan, PR China, a new species, Memnoniella sinensis, was identified. This new species is characterized by having phialidic conidiogenous cells with conspicuous collarettes, and aseptate, verrucose, ellipsoidal to sometimes ovoid, olivaceous brown to dark brown conidia. Morphologically, M. sinensis is similar to M. dichroa, but can be easily distinguished due to its hyaline conidiophores and smaller conidia. Phylogenetic analysis based on DNA sequences at five loci showed that our strain grouped together with M. dichroa and M. oenanthes. Here, the new species is described and illustrated, and a key to the species of the genus Memnoniella is provided.

A description is provided for Memnoniella dichroa , which can be found almost always on dead and rotting plant material. Some information on its associated organisms and substrata, dispersal and transmission, habitats and conservation status is given, along with details of its geographical distribution (North America (Mexico, USA (Florida, Kansas, Ohio)), Asia (China (Sichuan), Japan, Thailand, Turkey), Australasia (Australia (ACT), New Zealand), Caribbean (Cuba), Europe (Belgium, Denmark, Estonia, Germany, Ireland, Lithuania, Netherlands, Norway, Poland, Russia (Pskov Oblast, Republic of Karelia), UK)).

In this work, we discuss the use of multiway principal component analysis combined with comprehensive two-dimensional gas chromatography to study the volatile metabolites of the saprophytic fungus Memnoniella sp. isolated in vivo by headspace solid-phase microextraction. This fungus has been identified as having the ability to induce plant resistance against pathogens, possibly through its volatile metabolites. Adequate culture media were inoculated, and its headspace was then sampled with a solid-phase microextraction fiber and chromatographed every 24 h over seven days. The raw chromatogram processing using multiway principal component analysis allowed the determination of the inoculation period, during which the concentration of volatile metabolites was maximized, as well as the discrimination of the appropriate peaks from the complex culture media background. Several volatile metabolites not previously described in the literature on biocontrol fungi were observed, as well as sesquiterpenes and aliphatic alcohols. These results stress that, due to the complexity of multidimensional chromatographic data, multivariate tools might be mandatory even for apparently trivial tasks, such as the determination of the temporal profile of metabolite production and extinction. However, when compared with conventional gas chromatography, the complex data processing yields a considerable improvement in the information obtained from the samples.

Four novel metabolites have been isolated from a rice culture of Memnoniella echinata (JS6308) by solvent extraction and radial silica chromatography. The structures were elucidated by spectroscopic techniques, and the absolute stereochemistry of memnobotrin A determined by X-ray crystallography.

(The genus Stachybotrys (anamorphic fungi) in the semi-arid region of Brazil). Stachybotrys is characterized by macronematous, mononematous, unbranched or branched conidiophores, with discrete terminal and phialidic conidiogenous cells, and aseptate, reniform, ellipsoidal to spherical, smooth or verrucose conidia, which are produced in a slimy mass. Eight species have been reported from Brazil, occurring in the soil, air and leaf litter. During investigation of conidial fungi on decaying leaf litter in semi-arid areas of Brazil nine species were found: S. bisbyi (Sriniv.) G.L. Barron, S. chartarum (Ehrenb.) S. Hughes, S. globosa P. C. Misra & S. K. Srivast., S. kampalensis Hansf., S. longispora Matsush., S. nephrospora Hansf., S. nilagirica Subram., Stachybotrys parvispora S. Hughes and S. verrucispora Matsush. Stachybotrys nilagirica is a new record from Brazil. Descriptions, comments, geographic distribution and illustrations are presented for above mentioned species. A key for all species recorded in semi-arid region of Brazil is presented. (O gênero Stachybotrys (fungos anamórficos) na região semi-árida do Brasil). Stachybotrys é caracterizado por apresentar conidióforos macronemáticos, mononemáticos simples ou ramificados, células conidiogênicas evidentes, terminais e fialídicas e conídios asseptados, reniformes, elipsóides a esféricos, lisos ou verrucosos, produzidos em mucilagem. No Brasil já foram relatadas oito espécies, ocorrendo no solo, no ar e em material vegetal em decomposição. Durante investigação de fungos conidiais associados à serapilheira em áreas do semi-árido brasileiro foram encontradas nove espécies: S. bisbyi (Sriniv.) G.L. Barron, S. chartarum (Ehrenb.) S. Hughes, S. globosa P. C. Misra & S. K. Srivast., S. kampalensis Hansf., S. longispora Matsush., S. nephrospora Hansf., S. nilagirica Subram., S. parvispora S. Hughes e S. verrucispora Matsush., dentre estas S. nilagirica constitui um novo registro para o Brasil. Descrições, comentários, distribuição geográfica e ilustrações são apresentadas para as espécies citadas. Chave de identificação para as espécies registradas no Brasil é apresentada.

The conidial ontogeny of Memnoniella is very similar to that described for other phialidic Deuteromycotina. The persistence of the chain of conidia appears to be mostly due to the strength of the s...

1. Isolates of an intermediate nature between Memnoniella von Hohnel and Stachybotrys Corda have been observed.2. Stachybotrys-like slimy heads of elliptical to oval spores and Memnoniella-like hea...