Effect of bacterial volatiles on the mycelial growth of mushrooms.

Bacteria play an important role in the life cycle of fungi by influencing positively or negatively morphological features, mycelial growth and/or fruiting body induction. However, little is known about the underlying mechanisms and their species-dependence, especially among fungi of the phylum Basidiomycota. Hence, we analyzed the effects of seven bacterial isolates, that were previously obtained from Pleurotus ostreatus HK35, on the mycelial growth of P.

Generation of Flavor-Active Compounds by Electrochemical Oxidation of ()-Limonene.

Terpenes may be converted by electrochemical oxidation to various oxidized products with appealing aroma properties. In this study, ()-limonene was anodically oxidized in the presence of ethanol, and the resulting mixture exhibited a pleasing fruity, herbal, citrus-like, and resinous odor. The aroma-active compounds were purified by means of preparative high-performance liquid chromatography, and their structures were elucidated by means of gas chromatography (GC)-mass spectrometry and nuclear magnetic resonance spectroscopy.

High-resolution neural network-driven mapping of multiple diffusion metrics leveraging asymmetries in the balanced steady-state free precession frequency profile.

We propose to utilize the rich information content about microstructural tissue properties entangled in asymmetric balanced steady-state free precession (bSSFP) profiles to estimate multiple diffusion metrics simultaneously by neural network (NN) parameter quantification. A 12-point bSSFP phase-cycling scheme with high-resolution whole-brain coverage is employed at 3 and 9.4 T for NN input.

Biotechnological Production and Sensory Evaluation of ω1-Unsaturated Aldehydes.

Lipid extracts of the fungus were found to contain various scarce fatty acids including dodec-11-enoic acid and di- and tri-unsaturated C isomers. A biotechnological approach using a heterologously expressed carboxylic acid reductase was developed to transform the fatty acids into the respective aldehydes, yielding dodec-11-enal. Supplementation studies gave insights into the fungal biosynthesis of this rarely occurring acid and suggested a terminal desaturation of lauric acid being responsible for its formation.

Serves As a Gateway for Identifying Sesquiterpene Biosynthetic Enzymes in Higher Fungi.

Terpenoids constitute a structurally diverse group of natural products with wide applications in the pharmaceutical, nutritional, flavor and fragrance industries. Fungi are known to produce a large variety of terpenoids, yet fungal terpene synthases remain largely unexploited. Here, we report the sesquiterpene network and gene clusters of the black poplar mushroom Among 11 putative sesquiterpene synthases (STSs) identified in its genome, nine are functional, including two novel synthases producing viridiflorol and viridiflorene.

Industrial Riboflavin Fermentation Broths Represent a Diverse Source of Natural Saturated and Unsaturated Lactones.

Fermentation broths of from the industrial production of riboflavin emit an intense floral, fruity, and nutty smell. Typical Ehrlich pathway products, such as 2-phenylethan-1-ol and 2-/3-methylbutan-1-ol, were detected in large amounts as well as some intensely smelling saturated and unsaturated lactones, e.g.

Biosynthesis of Stereoisomers of Dill Ether and Wine Lactone by .

The white-rot fungus (PSA) biosynthesizes the bicyclic monoterpenoids 3,6-dimethyl-2,3,3a,4,5,7a-hexahydrobenzofuran (dill ether) () and 3,6-dimethyl-3a,4,5,7a-tetrahydro-1-benzofuran-2(3)-one (wine lactone) (). Submerged cultures grown in different media were analyzed by gas chromatography-mass spectrometry. The stereochemistry of the formed isomers was elucidated by comparing their retention indices to those of reference compounds by enantioselective multidimensional gas chromatography.

Enantiomeric ratios of 2-methylbutanoic acid and its methyl ester: Elucidation of novel biogenetic pathways towards (R)-methyl 2-methylbutanoate in a beverage fermented with shiitake.

Up to 35% of (R)-methyl 2-methylbutanoate (M2MB) was observed in a beverage fermented with shiitake. As M2MB naturally occurs typically in high excesses of the (S)-enantiomer, the origin of the (R)-ester was elucidated by stable isotope labeled precursor-feeding studies. (R)-2-Methylbutanoic acid was identified as the main precursor in the substrate wort.

Aroma Characterization and Safety Assessment of a Beverage Fermented by Trametes versicolor.

A cereal-based beverage was developed by fermentation of wort with the basidiomycete Trametes versicolor. The beverage possessed a fruity, fresh, and slightly floral aroma. The volatiles of the beverage were isolated by liquid-liquid extraction (LLE) and additionally by headspace solid phase microextraction (HS-SPME).