Biotransformation of [U-13C]linoleic acid suggests two independent ketonic- and aldehydic cycles within C8-oxylipin biosynthesis in Cyclocybe aegerita (V. Brig.) Vizzini

Antifungal Volatile Organic Compounds from Talaromyces purpureogenus CEF642N: Insights from One Strain Many Compounds (OSMAC) Strategy for Controlling Verticillium dahliae in Cotton

Verticillium wilt is a devastating soil-borne disease that significantly impacts cotton production, necessitating the development the effective biofumigants for its control. In this study, the inhibitory effect of total volatile organic compounds (VOCs) produced by Talaromyces purpureogenus CEF642N against Verticillium dahliae were evaluated using the one strain many compounds (OSMAC) strategy and analyzed through volatile metabolome. CEF642N was found to produce two primary VOCs, 3-octanol and 2-octenal, (E)-, both of which demonstrated significant antifungal activity. Transcriptome analysis of mycelium grown on various solid media revealed notable differences in the expression of genes associated with arachidonic acid metabolism, lipoxygenase (LOX), and lytic enzymes. These findings provide a foundation for future research aimed at identifying key genes involved in the eight-carbon volatile biosynthetic pathway.

The improvement mechanism of volatile for cooked Tibetan pork assisted with ultrasound at low-temperature: Based on the differences in oxidation of lipid and protein

Low-temperature cooking causes flavor weakness while improving the texture and digestive properties of meat. To enhance the flavor of low-temperature cooked Tibetan pork, samples were cooked at low-temperature with or without ultrasound-assisted (UBTP, BTP) for different times (30 min, 90 min) and then analyzed using GC-MS and LC-MS. The results showed that ultrasound-assisted cooking caused a significant increase in lipid oxidation by 9.10% in the early stage of the treatment. Additionally, at the later stage of ultrasound-assisted processing, proteins were oxidized and degraded, which resulted in a remarkable rise in the protein carbonyl content by 6.84%. With prolonged effects of ultrasound and low-temperature cooking, the formation of phenylacetaldehyde in UBTP-90 sample originated from the degradation of phenylalanine through multivariate statistics and correlation analysis. Meanwhile, trans, cis-2,6-nonadienal and 1-octen-3-one originated from the degradation of linolenic acid and arachidonic acid. This study clarified the mechanism of ultrasound-assisted treatment improving the flavor of low-temperature-cooked Tibetan pork based on the perspective of lipids and proteins oxidation, providing theoretical supports for flavor enhancement in Tibetan pork-related products.

Identification of volatile producing enzymes in higher fungi: Combining analytical and bioinformatic methods

Filamentous fungi harbor the genetic potential for the biosynthesis of several secondary metabolites including various volatile organic compounds (VOCs). Nonetheless, under standard laboratory conditions, many of these VOCs are not formed. Furthermore, little is known about enzymes involved in the production of fungal VOCs. To tap these interesting topics, we developed an approach to identify enzymes putatively involved in the fungal VOC biosynthesis. In this chapter, we highlight different fungal cultivation methods and techniques for the extraction of VOCs, including a method that allows the noninvasive analysis of VOCs. In addition using terpene synthases as an example, it is depicted how enzymes putatively involved in VOC synthesis can be identified by means of bioinformatic approaches. Transcriptomic data of chosen genes combined with volatilome data obtained during different developmental stages is demonstrated as a powerful tool to identify enzymes putatively involved in fungal VOC biosynthesis. Especially with regard to subsequent enzyme characterization, this procedure is a target-oriented way to save time and efforts by considering only the most important enzymes.