Enhanced Mycelium Production of Phellinus igniarius (Agaricomycetes) Using a He-Ne Laser with Pulsed Light.

This study used a He-Ne laser with pulsed light irradiation to produce mutant strains of Phellinus igniarius strain JQ9 with enhanced characteristics for fermentation (17.685 ± 3.092 g/L) compared with the parent strain (12.062 ± 1.119 g/L). The combined treatment conditions were as follows: He-Ne laser irradiation for 30 min using a spot diameter of 10 mm, pulsed light treatment power set at 100 J, a treatment distance of 14.5 cm, and a flash frequency of 0.5 s. The production of bioactive polysaccharides and small biocompounds such as polyphenols, flavonoids, and triterpenes increased together with mycelium production. The results showed that polyphenol content was significantly correlated with L*, a*, and b* values (R = -0.594, P < 0.01; R = 0.571, P < 0.01; and R = 0.500, P < 0.05; respectively). Antagonistic and random amplified polymorphic DNA analyses indicated that the genetic material of the screened mutants was altered. The mutant screening using a He-Ne laser with pulsed light irradiation could be an effective method for the development of Phellinus strains and could thus improve mycelium production.

Screening for proteins related to the biosynthesis of hispidin and its derivatives in Phellinus igniarius using iTRAQ proteomic analysis.

BACKGROUND: Hispidin (HIP) and its derivatives, a class of natural fungal metabolites, possess complex chemical structures with extensive pharmacological activities. Phellinus igniarius, the most common source of HIP, can be used as both medicine and food. However, the biosynthetic pathway of HIP in P. igniarius remains unclear and we have a limited understanding of the regulatory mechanisms related to HIP. In this work, we sought to illustrate a biosynthesis system for hispidin and its derivatives at the protein level. RESULTS: We found that tricetolatone (TL) is a key biosynthetic precursor in the biosynthetic pathway of hispidin and that its addition led to increased production of hispidin and various hispidin derivatives. Based on the changes in the concentrations of precursors and intermediates, key timepoints in the biosynthetic process were identified. We used isobaric tags for relative and absolute quantification (iTRAQ) to study dynamic changes of related proteins in vitro. The 270 differentially expressed proteins were determined by GO enrichment analysis to be primarily related to energy metabolism, oxidative phosphorylation, and environmental stress responses after TL supplementation. The differentially expressed proteins were related to ATP synthase, NAD binding protein, oxidoreductase, and other elements associated with electron transfer and dehydrogenation reactions during the biosynthesis of hispidin and its derivatives. Multiple reaction monitoring (MRM) technology was used to selectively verify the iTRAQ results, leading us to screen 11 proteins that were predicted to be related to the biosynthesis pathways. CONCLUTION: These findings help to clarify the molecular mechanism of biosynthesis of hispidin and its derivatives and may serve as a foundation for future strategies to identify new hispidin derivatives.

Genome comparison and transcriptome analysis of the invasive brown root rot pathogen, Phellinus noxius, from different geographic regions reveals potential enzymes associated with degradation of different wood substrates.

Phellinus noxius is a root-decay pathogen with a pan-tropical/subtropical distribution that attacks a wide range of tree hosts. For this study, genomic sequencing was conducted on P. noxius isolate P919-02W.7 from Federated States of Micronesia (Pohnpei), and its gene expression profile was analyzed using different host wood (Acer, Pinus, Prunus, and Salix) substrates. The assembled genome was 33.92 Mbp with 2954 contigs and 9389 predicted genes. Only small differences were observed in size and gene content in comparison with two other P. noxius genome assemblies (isolates OVT-YTM/97 from Hong Kong, China and FFPRI411160 from Japan, respectively). Genome analysis of P. noxius isolate P919-02W.7 revealed 488 genes encoding proteins related to carbohydrate and lignin metabolism, many of these enzymes are associated with degradation of plant cell wall components. Most of the transcripts expressed by P. noxius isolate P919-02W.7 were similar regardless of wood substrates. This study highlights the vast suite of decomposing enzymes produced by P. noxius, which suggests potential for degrading diverse wood substrates, even from temperate host trees. This information contributes to our understanding of pathogen ecology, mechanisms of wood decomposition, and pathogenic/saprophytic lifestyle.