The Combination of Iron and Copper Increases Pathogenicity and Induces Proteins Related to the Main Virulence Factors in Clinical Isolates of Cryptococcus neoformans var. grubii

A functional intact SUMOylation machinery in Aspergillus flavus contributes to fungal and aflatoxin contamination of food

SUMO adducts occur in Aspergillus flavus, and are implicated in fungal biology, while the underlying mechanism and the SUMOylation apparatus components in this saprophytic food spoilage mould, remain undefined. Herein, genes encoding SUMOylation cascade enzymes in A. flavus, including two heterodimeric SUMO E1 activating enzymes, a unique SUMO E2 conjugating enzyme, and one of SUMO E3 ligases, were identified and functionally analyzed. Global SUMO adducts immunoassay, multiple morphological comparison, aflatoxin attributes test, fungal infection and transcriptomic analyses collectively revealed that: E1 and E2 were essential for intracellular SUMOylation, and contributed to both stress response and fungal virulence-related events, including sporulation, colonization, aflatoxins biosynthesis; the primary E3 in this fungus, AfSizA, might serve as the molecular linkage of SUMOylation pathway to fungal virulence rather than SUMOylation-mediated stress adaptation. These findings demonstrated that SUMOylation machinery in A. flavus was functionally intact and contributed to multiple pathobiological processes, hence offering ideas and targets to control food contamination by this mycotoxigenic fungus.

Phylloplane Biodiversity and Activity in the City at Different Distances from the Traffic Pollution Source

The phylloplane is an integrated part of green infrastructure which interacts with plant health. Taxonomic characterization of the phylloplane with the aim to link it to ecosystem functioning under anthropogenic pressure is not sufficient because only active microorganisms drive biochemical processes. Activity of the phylloplane remains largely overlooked. We aimed to study the interactions among the biological characteristics of the phylloplane: taxonomic diversity, functional diversity and activity, and the pollution grade. Leaves of Betula pendula were sampled in Moscow at increasing distances from the road. For determination of phylloplane activity and functional diversity, a MicroResp tool was utilized. Taxonomic diversity of the phylloplane was assessed with a combination of microorganism cultivation and molecular techniques. Increase of anthropogenic load resulted in higher microbial respiration and lower DNA amount, which could be viewed as relative inefficiency of phylloplane functioning in comparison to less contaminated areas. Taxonomic diversity declined with road vicinity, similar to the functional diversity pattern. The content of Zn in leaf dust better explained the variation in phylloplane activity and the amount of DNA. Functional diversity was linked to variation in nutrient content. The fraction of pathogenic fungi of the phylloplane was not correlated with any of the studied elements, while it was significantly high at the roadsides. The bacterial classes Gammaproteobacteria and Cytophagia, as well as the Dothideomycetes class of fungi, are exposed to the maximal effect of distance from the highway. This study demonstrated the sensitivity of the phylloplane to road vicinity, which combines the effects of contaminants (mainly Zn according to this study) and potential stressful air microclimatic conditions (e.g., low relative air humidity, high temperature, and UV level). Microbial activity and taxonomic diversity of the phylloplane could be considered as an additional tool for bioindication.