Regulation of differentiation of the dimorphic fungus Paecilomyces viridis by nitrogen sources, antibiotics and metabolic inhibitors

Asymmetric total synthesis of paecilomycin C through intramolecular nucleophilic ring opening of an epoxide

An efficient asymmetric total synthesis of naturally occurring resorcylic acid lactone (RAL) paecilomycin C was achieved by employing carboxylate assisted 5-exo-tet ring opening of an epoxide as a key reaction.

Resorcylic acid lactones (RALs) and their structural congeners: recent advances in their biosynthesis, chemical synthesis and biology

Resorcylic acid lactones (RALs) are naturally occurring 14-membered macrolactones that constitute a class of polyketides derived from fungal metabolites and that possess significant and promising biological activity.

Disseminated mycosis in veiled chameleons (Chamaeleo calyptratus) caused by Chamaeleomyces granulomatis, a new fungus related to Paecilomyces viridis

An outbreak of disseminated granulomatous disease occurred in a group of veiled chameleons (Chamaeleo calyptratus) in a zoo collection. An adult female and six offspring developed large granulomas in multiple organs and were euthanized. At necropsy, roughly spherical yellow-to-white nodules 1 to 3 mm in diameter were grossly visible in the liver and other organs. Histopathology revealed fungal elements that were spherical to ovoid in shape, fragments of slender to irregularly swollen hyphae, and occasional conidia produced on phialides. Fungal isolates were initially suspected on the basis of morphology results to represent Paecilomyces viridis, a species known only from one outbreak of fatal mycosis in carpet chameleons (Furcifer lateralis). Data obtained from morphological studies and from phylogenetic analyses of nuclear ribosomal rRNA (rDNA) sequence data revealed the Danish chameleon isolates to be a related undescribed anamorphic species within the family Clavicipitaceae that includes many insect pathogens. Chamaeleomyces granulomatis gen. et sp. nov. is given as the name for the newly described fungus, and P. viridis is transferred to the new genus as Chamaeleomyces viridis comb. nov. Chamaeleomyces species are distinguished by having basally swollen phialides tapering to a narrow neck, conidia in fragile chains, and pale green to greenish-gray colonies. Both species are dimorphic, producing a transitory yeast stage characterized by ovoid-to-subglobose or subcylindrical yeast-like cells. Chamaeleomyces species appear to be rare but aggressive pathogens of chameleons.

Biological effects of the antibiotic brefeldin A (decumbin, cyanein, ascotoxin, synergisidin): a retrospective

Brefeldin A has been recently characterized to act as an inhibitor of intracellular protein export with profound effects on the structure and function of the Golgi apparatus in animal cells. Manifold activities of the antibiotic (under different names) published in the 1960's and 1970's are reviewed: effects on fungal growth and morphogenesis, inhibition of mitosis in plant cells, cytotoxicity, cancerostatic, antiviral and antinematodal activity and peculiar effects on DNA, RNA and protein synthesis in microbial and animal cells.

Antifungal agents as tools in experimental mycology

Both natural and synthetic substances are conveniently used for studying metabolism, genetic aspects, morphogenesis of cell structures, life cycle and differentiation of fungi.

The use of antibiotics for studies of morphogenesis and differentiation in microorganisms

Numerous antibodies with a known mechanism of action are utilized as possible means for studying morphogenesis and differentiation. Inhibitors of biosynthesis of nucleic acids and proteins, compounds intervening with the synthesis and/or function of cell walls and membranes or compounds influencing the energy metabolism are particularly useful. The use of antibiotics for studies of the life cycle of viruses, bacteria, fungi, myxomycetes, protozoa and algae is analyzed in the present communication. Certain aspects of morphogenesis and functions of mitochondria and plastids were clarified with the aid of antibiotics. Relationships between production of antibiotics and differentiation of their producers are discussed in the final part of the paper.