Jul 2026· Applied Microbiology and Biotechnology· 0 citations
Abstract
Fungal pigments hold significant food industrial value due to their safe and sustainable properties. Here we identified a naturally occurring coculture pair
Epicoccum nigrum
SPDX618 and
Mucor racemosus
SPDX522 in vinegar mash that produced red pigments, which was not observed in either monoculture. Our results showed that
E. nigrum
acted as the pigment producer while
M. racemosus
served as the elicitor. Response surface methodology and pH stabilization strategy improved the yield of red pigment into 328.7 U/g. Through bioactivity-guided fractionation coupled with UHPLC-MS/MS and in silico structure reconstitution, four red pigments were preliminarily assigned as anthracycline-like compounds. RNA-seq analysis revealed a putative dual-PKS gene cluster (SPDX618009169–SPDX618009178) with exclusively upregulation in cocultured
E. nigrum
that is potentially involved in red pigment biosynthesis. Besides, the production of the yellow pigment epipyrone was reduced in cocultured
E. nigrum
, consistent with the downregulated transcription level of its biosynthesis genes. Comparative metabolomics analysis further revealed a broad downregulation in both of primary metabolism and secondary metabolism in coculture system, indicating that a competition interaction relationship also existed between
E. nigrum
and
M. racemosus
. Altogether, this study reports a fungal coculture system that exhibited red pigments production. These findings contribute to the understanding of microbial interaction-driven metabolite biosynthesis and may provide a foundation for future exploration of their potential application as a colorant.
•
An Epicoccum nigrum–Mucor racemosus coculture system was identified to produce red pigment for the first time.
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E. nigrum acts as the red pigment producer and M. racemosus serves as the elicitor.
•
RNA-seq analysis tentatively identified a putative dual-PKS gene cluster upregulated in coculture that is putatively involved in red pigment biosynthesis.
The metabolic cooperation between plants and their endophytic fungi represents a promising frontier in the biosynthesis of natural products. This study elucidates the contribution of the endophytic fungus Fusarium oxysporum Po18 to the production of aromatic polyketides that drive specialized metabolism in Peperomia obtusifolia. Cultivation parameters for F. oxysporum were optimized using a Central Composite Rotatable Design (CCRD), revealing that mild temperatures (28 °C) and extended incubation (9 days) maximized orsellinic acid accumulation. LC–MS/MS identified orsellinic acid as [M–H]– at m/z 167.0356, with the diagnostic fragment ion m/z 122.8924, and quantified by HPLC–DAD, achieving a concentration of 132 μg/mL under optimized conditions. Comparative metabolomic analysis and molecular networking (GNPS) revealed related fungal metabolites, including lecanoric acid, 6-methylsalicylic acid, and citrinin, all derived from the fungal polyketide synthase (PKS) pathway. These metabolites are proposed to act as biosynthetic precursors for chroman and benzopyran derivatives previously reported in P. obtusifolia. The results provide the first experimental evidence of a biosynthetic partnership between Fusarium and Peperomia, in which the endophyte may supply aromatic scaffolds that could subsequently undergo downstream modifications in the host plant. This study expands the understanding of fungal–plant metabolic interactions and highlights F. oxysporum as a sustainable biotechnological source of aromatic polyketides with potential applications in natural product chemistry and biocatalysis.
Wellington Gomes de Lima, A. D. A. Morandim-Giannetti, João Luiz Bronzel Junior et al.· ACS Omega· 0 citations
Low-cost lignocellulosic residues offer a sustainable route to fungal pigment production. In this study, six biomass residues were evaluated as culture-medium supplements for Arthrinium phaeospermum, and their chemical constituents that may be associated with enhanced red pigment production were investigated. Fungal growth, pigment production, and pigment productivity were measured on biomass-amended potato dextrose agar. Following initial screening, Paulownia powder and sugarcane bagasse were selected, and their concentrations were optimized in mixed media. Ethanolic extracts of both materials were characterized using Fourier-transform infrared spectroscopy and ultra-performance liquid chromatography–mass spectrometry, and four major Paulownia-derived compounds were individually evaluated. The optimal medium, containing 4 mg/mL Paulownia powder and 3 mg/mL sugarcane bagasse, produced 3.09 g/L red pigment, representing a 2.02-fold increase over the control. Sugarcane bagasse primarily promoted fungal growth, whereas paulownia enhanced pigment productivity. Among the tested compounds, 0.2 mg/mL 4-methylumbelliferone (4M) showed the strongest stimulatory effect, increasing pigment production 3.01-fold over the control. These findings demonstrate that combining forestry and agro-industrial residues can simultaneously support fungal growth and pigment production. Paulownia-derived coumarins, particularly 4-methylumbelliferone, may contribute to this stimulatory effect and warrant further mechanistic investigation.
Boxi Chen, Xin-Pei Chu, Zi-Hua Su et al.· Microbiology Research· 0 citations
A side-by-side benchmark of these two marine diatoms is provided, offering a data-driven reference for process development and industrial deployment of microalgae-derived fucoxanthin, and high-yield induction methods from the dimensions of nutrient regulation, light optimization, exogenous induction, and strain improvement are summarized.
Man Zhang, Hao-Yu Li, Feichao Du et al.· Marine Drugs· 0 citations
The characteristic red walnut germplasm ‘RW-1′ (Juglans regia L.) exhibits a stable red seed coat phenotype due to the abundant accumulation of anthocyanins and proanthocyanidins (PAs). The regulatory mechanisms underlying PA biosynthesis in red walnut remain poorly studied, which hinders the improvement of walnut color quality. Leucoanthocyanidin reductase (LAR) is a key enzyme in the PA metabolic pathway, while its function in red walnut remains unclear. Here, the leucoanthocyanidin reductase gene JrLAR1, whose expression pattern is consistent with the accumulation trend of PAs, was cloned from the seed coats of red walnut ‘RW-1′, and its function in PA biosynthesis was verified via heterologous overexpression in Arabidopsis thaliana, a well-recognized cross-species LAR functional validation system free of endogenous LAR interference due to absent native homologs. The results showed that the full-length coding sequence (CDS) of JrLAR1 gene is 1104 bp, encoding a 367-amino-acid protein belonging to the NADB_Rossmann superfamily, and the protein shares an extremely high sequence similarity with grape VvLAR2. Heterologous overexpression of JrLAR1 significantly increased total PA content in the leaves and seeds of A. thaliana. Integrated transcriptomic and metabolomic analyses further revealed that JrLAR1 overexpression markedly upregulated the core genes involved in PA metabolism and the transcription factor GL3 in A. thaliana, specifically induced (+)-catechin synthesis, and ultimately promoted the significant accumulation of procyanidin B3. In addition, a set of antioxidant enzyme-encoding genes were substantially upregulated in JrLAR1-overexpressing A. thaliana lines. Yeast one-hybrid and dual-luciferase reporter assays demonstrated that JrEGL1b, a homolog of A. thaliana GL3, can bind to the promoter region of JrLAR1 gene and significantly enhance its transcriptional activity. Transient overexpression of JrLAR1 or JrEGL1b in red walnut leaves significantly promoted PA accumulation, and JrEGL1b overexpression notably upregulated JrLAR1 expression. In conclusion, JrLAR1 plays a crucial role in PA biosynthesis in red walnut and is positively regulated by the transcription factor JrEGL1b. These findings improve the molecular regulatory network of pigment metabolism in red walnut and provide valuable molecular targets for the quality improvement and directional breeding of walnuts.
Wei Zhao, Yinan Huang, Weihan Ma et al.· Horticulturae· 0 citations
The content of extracellular Monascus pigments (eMPs), which has strong functional activity and stability, was improved by adding glycine in previous research. This study systematically elucidated the effects of different glycine concentrations on Monascus purpureus (M. purpureus) S109 eMPs production at both the membrane physiological level and the molecular level of pigment secretion-related gene expression. By measuring the biomass, fatty acid, relative conductivity, fluorescence intensity of tyrosine and tryptophan, membrane potential and ion concentration, coenzyme content, and eMPs content, it was found that 2 g/L glycine could significantly enhance cell membrane fluidity and permeability, and promote the production of eMPs, with their content increasing from 85.82 U/mL to 384.88 U/mL. Under this condition, apart from the negative regulator MrpigI, and the MrpigH directly involved in yellow pigment synthesis, which were down-regulated, all other genes associated with the pigment biosynthesis pathway were significantly up-regulated. Furthermore, the expression of MrpigL and MrpigP genes involved in pigment secretion was significantly up-regulated by 2.8-fold and 10.9-fold, respectively. This study demonstrates that glycine promotes eMPs secretion through modulation of membrane physiological properties and modulation of secretion-related gene expression.
Sixu Lin, Xue Yang, Junyao Wang et al.· Microbial Cell Factories· 0 citations
Results suggest that J-G crude elicitor treatment may be a useful induction strategy for increasing resveratrol and polydatin accumulation in RGT sterile seedlings and provide candidate genes for future functional validation.
Jingru Liang, Yang Zhang, Xintao Li et al.· Current Microbiology· 0 citations
