Characteristics Of The Red Pigments Produced By Talaromyces Atroroseus And Its Related Genes

Natural products are the pivotal way to obtain industrial or medicinal raw materials,while the secondary metabolites of fungi as an important source of natural active molecules are increasingly concerned by researchers.In this article,the secondary metabolites and regulatory genes of a filamentous fungus Talaromyces atroroseus were studied.First,the storage stability and antioxidant activity of the red pigment secreted by the strain were measured.And the structure of some molecules in red pigment was characterized by separation and spectroscopy techniques.Finally,the key genes participate in the synthesis of pigments were identified through RNA-seq analysis.1. The color value,stability and antioxidant activity of the red pigment produced by T.atroroseus were determined.The results showed that the red pigment had the maximum absorption at 510nm,with the color value reaching 363.2.It has good antioxidant properties and resists to visible light or temperature below 50?;the pigments residual rate is higher than 90%under the influence of other metal ions except Fe³⁺;The pigment is stable under the influence of common food additives agents and acid/alkaline environments,contrary to high temperature and ultraviolet light.2. The composition and structural characteristics of red pigment are analyzed.T.atroroseus produces complex pigments composition consisting of several yellow-green components and dozens of red substances.Five kinds of red products were obtained by means of normal phase silica gel and ODS separation.The spectroscopy identification results shows that the five substances have the same structure of the core and different fatty chains,they have a consistent degree of conjugation,similar to Monascus pigment.The molecule separated from the ethyl acetate phase called N-glutarylmonascorubramine,with a molecular weight of 511.23 and molecular formula C₂₈H₃₃NO₈.A molecule with molecular weight of 575.2?molecular formula of C₃₂H₃₃NO₉ was obtained from n-butanol part,of which side chain was presumed to contain a phenol substituent.Three isomers with a molecular weight of 526.2?molecular formula of C₂₇H₃₀N₂O₉ were also obtained from n-butanol part.3. In order to explore the genes related to pigment synthesis,we performed transcriptome analysis of T.atroroseus.Results showed that the polyketide synthase?short-chain dehydrogenase?short-chain alcohol dehydrogenase with different specificity??non-ribosomal peptide synthase?methyltransferase?cytochrome P450 and ketoreductase domain related genes or domains are mainly involved in controlling the assembly and structural diversification of red pigment.