Project description:Desarmillaria tabescens is one of the most important edible, medicinal, and phytopathogenic basidiomycetes. The complete mitochondrial genome of this species was determined using next-generation sequencing technology. This mitogenome is a circular molecule of 93,439 bp with a GC content of 29.28% and contains 15 protein-coding, two rRNA (rnl and rns), and 24 tRNA genes. Phylogenetic analysis revealed that D. tabescens is genetically closest to Agrocybe aegerita. Desarmillaria tabescens mitogenome can contribute to our understanding of the phylogeny and evolution of this species.
Project description:Forage grain contamination with aflatoxin B1 (AFB1) is a global problem, so its detoxification with the aim of providing feed safety and cost-efficiency is still a relevant issue. AFB1 degradation by microbial enzymes is considered to be a promising detoxification approach. In this study, we modified an previously developed Pichia pastoris GS115 expression system using a chimeric signal peptide to obtain a new recombinant producer of extracellular AFB1 oxidase (AFO) from Armillaria tabescens (the yield of 0.3 g/L), purified AFO, and selected optimal conditions for AFO-induced AFB1 removal from model solutions. After a 72 h exposure of the AFB1 solution to AFO at pH 6.0 and 30 °C, 80% of the AFB1 was degraded. Treatments with AFO also significantly reduced the AFB1 content in wheat and corn grain inoculated with Aspergillus flavus. In grain samples contaminated with several dozen micrograms of AFB1 per kg, a 48 h exposure to AFO resulted in at least double the reduction in grain contamination compared to the control, while the same treatment of more significantly (~mg/kg) AFB1-polluted samples reduced their contamination by ~40%. These findings prove the potential of the tested AFO for cereal grain decontamination and suggest that additional studies to stabilize AFO and improve its AFB1-degrading efficacy are required.
