Characterization of three novel pigment-producing Penicillium strains isolated from the Mexican semi-desert

Fungal pigments are used in diverse industries such as food, pharmaceuticals, textile, among others. The need of new organic pigments involves the search for new microbial sources. In this study, three fungal strains isolated from Quercus sp and Larrea tridentata were morphological, physiological and molecularly characterized. Different temperatures (8, 16, 20, 24 and 32°C) and pH (4, 6, 7, 8 and 10) levels were tested to determine the best conditions to produce a fungal pigment under submerged and solid state fermentation. The three strains were genotyped by using polymerase chain reactionrestriction fragment length polymorphism (PCR-RFLP), random amplified polymorphic DNA (RAPD), inter-transcript spaces (ITS) and intergenic spaces (IGS) with the object to eliminate duplications. The strains were identified according to their morphology as Penicillium purpurogenum (GH2) and Penicillium pinophilum (EH2 and EH3). It was found that at submerged state fermentation to 24°C and pH 10, the three strains produced pigments, but P. purpurogenum GH2 strain produced the highest amount of pigments (1.25 U). According to the molecular analysis, it was found that all strains were different. This is to our knowledge the first report on characterization of fungal strains isolated from the Mexican semi-desert which have potential for pigment production.Keywords: Penicillium purpurogenum, Penicillium pinophilum, intergenic spaces (IGS), inter-transcript spaces (ITS), pigments, polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), submerged and solid state fermentationAfrican Journal of Biotechnology Vol. 12(22), pp. 3405-341

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field