Penicillium brevicompactum as a novel source of natural pigments with potential for food applications

Chemical characterization, antioxidant activity and activation of macrophages RAW264.7 via MAPK signaling pathway of the exopolysaccharide from Penicillium EF-2

BACKGROUND

Microbial exopolysaccharides represent a significant source of polysaccharides, with their production unconstrained by temporal or spatial limitations. Penicillium, a filamentous fungus widely recognized for its medicinal food applications, is known to produce exopolysaccharides that exhibit cancer-inhibitory properties.

RESULTS

In the present study, exopolysaccharides from Penicillium EF-2 (EPS) were extracted and structurally characterized using ion chromatograph, infrared spectroscopy and NMR. The in vitro antioxidant and immunomodulatory activities were also investigated. EPS has a molecular weight of 111.47 kDa, is primarily composed of mannose, glucose and galactose, possesses a crystalline region, and exhibits excellent thermal properties. In free radical scavenging assays, EPS demonstrated robust in vitro antioxidant activity. Furthermore, EPS activated the mitogen-activated protein kinase pathway, enhancing the immunomodulatory capacity of macrophages.

CONCLUSION

EPS has excellent antioxidant and biological activities. The present study provides a theoretical basis for the utilization of EPS and offers new ideas for active sources of Penicillium fermented foods. © 2025 Society of Chemical Industry.

Characterization of the Red Dye From Arthrinium phaeospermum and Its Application in Wood Dyeing

The aim of this study was to investigate the production, stability and applicability of dyes produced by filamentous fungi isolated from wood. First, the effect of culture conditions on fungal growth and dye production was investigated. The dyes were experimentally studied for solubility and stability and chemically characterized by FT-IR and UPLC-Q-EXACTIVE-MS. Finally, the dye was used to evaluate its industrial applicability by staining a variety of woods. The results showed that the filamentous fungus Arthrinium phaeospermum was able to produce red water-soluble pigments, which were thermally and ultraviolet stable and remained stable in pH 1-9. Chemical analysis showed that the red dye contained the chromogenic substances bostrycin and about 7.01% of griseofulvin. Dyeing experiments showed that the red dye was able to give the wood a red color and a natural grain. The results of various experiments indicate that A. phaeospermum has the potential to produce dyes for use in the wood dyeing and textile industries.

Metabolomics analysis based on UHPLC-QTOF-MS/MS to explore the synthesis mechanism and culture conditions optimization of Penicillium EF-2 exopolysaccharide

Penicillium exopolysaccharide (EPS) inhibits galactose lectins and enhances immunity. However, EPS production is low and its synthesis mechanism remains unclear. Penicillium EF-2 strains with high EPS production were selected for this study, and Penicillium fermentation conditions were subsequently improved. The optimal culture conditions were 30 g/L lactose, 6 g/L yeast extract powder, 4 d seed age, 10 % inoculation amount, 3 d of secondary fermentation time, and the final EPS yield was 3.97 g/L. UHPLC-Q-TOF-MS/MS was used to explore the mechanism of EPS synthesis at the metabolic level. Optimal carbon source: lactose and optimal nitrogen source: yeast extract can provide precursors for EPS synthesis through related metabolic pathways. Moreover, regulating the energy, vitamin, and lipid metabolic pathways created favourable conditions for EPS synthesis and secretion. These findings explain the mechanism of EPS synthesis at the metabolic level and provide a theoretical basis for optimising and industrialising EPS production.

Abundance and diversity of fungal endophytes isolated from monk fruit (Siraitia grosvenorii) grown in a Canadian research greenhouse

Monk fruit (Siraitia grosvenorii) is an herbaceous perennial vine of the Cucurbitaceae family cultivated commercially mainly in southern China. There is very little information available about the fungal endophytes in monk fruit. In this study, monk fruit plants were grown from seeds in a research greenhouse at Kwantlen Polytechnic University in British Columbia, Canada to explore the abundance and diversity of their fungal endophytes. Fungal endophytes were isolated from seeds, seedlings, mature monk fruit plants, and fruits, and cultured on potato dextrose agar and water agar media. Isolates were identified by microscopic examination and BLAST comparison of ITS sequences to published sequences in GenBank. At least 150 species of fungal endophytes representing 60 genera and 20 orders were recovered from monk fruit tissues. Non-metric multidimensional scaling (NMDS) was carried out to explore the similarity of fungal communities among roots, stems, leaves, flowers, fruits, and seeds based on fungal orders. Our study showed that monk fruit plants are a rich source of fungal endophytes with the greatest abundance and diversity in leaves. This work has deepened our understanding of the intricate interactions between plants and fungi that sustain ecosystems and underpin plant health and resilience.

Diverse biological activities and secondary metabolites profile of Penicillium brevicompactum HE19ct isolated from the high-Andean medicinal plant Perezia coerulescens

Endophytic fungi produced attractive primary and secondary metabolites for industries, pharmacology, and biotechnology. The bioactive potential of HE19ct, identified as Penicillium brevicompactum according to ITS-BenA-caM, was addressed. Antimicrobial and antioxidant activities and secondary metabolite contents using four culture media in Agar-plate (ApF) and Submerged (SmF) fermentation were evaluated. Some plant growth-promoting (PGP) traits and their related genes were tested. HE19ct exhibited antimicrobial activity against Staphylococcus aureus, Enterococcus faecalis, Candida albicans, C. tropicalis, Fusarium sp., Geotrichum candidum, and Alternaria sp. All cultures showed DPPH scavenging activity and phenolic compounds, where ethyl acetate extract of SmF with malt extract showed higher activity and SmF/ApF with potato-dextrose exhibited higher yield, respectively. HE19ct solubilized tricalcium-phosphate and produced siderophore, endoglucanase, proteinase, and amylase. It enhanced the alfalfa's germination at 15 °C, root development, and phenols production at 15 and 24 °C. Phenols, tannins, anthraquinones, triterpenoids/steroids, and alkaloids production were detected depending on culture media. Polyketide synthase type I gene (PksI), subtilisin-like protease prb 1 (Pbr), and siderophore D (sidD) were PCR-amplified. Finally, HE19CT could be a promising source of interesting bioactive compounds for pharmacology and agriculture mainly in extreme conditions, then metabolomic and functional genetic research must be performed to support their appropriate application.

Red biocolorant from endophytic Talaromyces minnesotensis: production, properties, and potential applications

Fungal colorants are gradually entering the global color market, given their advantages of being less harmful to human health, as well as having greater stability and biotechnological potential, compared to other natural sources. The present work concerns the isolation and identification of an endophytic filamentous fungus, together with the chemical characterization and assessment of the fluorescence, toxicity, stability, and application potential of its synthesized red colorant. The endophytic fungus was isolated from Hymenaea courbaril, a tree from the Brazilian savannah, and was identified as Talaromyces minnesotensis by phenotypic and genotypic characterization. Submerged cultivation of the fungus resulted in the production of approximately 12 AU₅₀₀ of a red biocolorant which according to LC-DAD-MS analysis is characterized by being a complex mixture of molecules of the azaphilone class. Regarding cytotoxicity assays, activity against human hepatoblastoma (HepG2) cells was only observed at concentrations above 5.0 g L^-1, while antimicrobial effects against pathogenic bacteria and yeast occurred at concentrations above 50.0 g L^-1. The biocolorant showed high stability at neutral pH values and low temperatures (10 to 20 °C) and high half-life values (t_1/2), which indicates potential versatility for application in different matrices, as observed in tests using detergent, gelatin, enamel, paint, and fabrics. The results demonstrated that the biocolorant synthesized by Talaromyces minnesotensis has potential for future biotechnological applications. KEY POINTS: • An endophytic fungus, which was isolated and identified, synthesize a red colorant. • The colorant showed fluorescence property, low toxicity, and application potential. • The red biocolorant was highly stable at pH 8.0 and temperatures below 20°C.

Fungal Pigments: Carotenoids, Riboflavin, and Polyketides with Diverse Applications

Natural pigments and colorants have seen a substantial increase in use over the last few decades due to their eco-friendly and safe properties. Currently, customer preferences for more natural products are driving the substitution of natural pigments for synthetic colorants. Filamentous fungi, particularly ascomycetous fungi (Monascus, Fusarium, Penicillium, and Aspergillus), have been shown to produce secondary metabolites containing a wide variety of pigments, including β-carotene, melanins, azaphilones, quinones, flavins, ankaflavin, monascin, anthraquinone, and naphthoquinone. These pigments produce a variety of colors and tints, including yellow, orange, red, green, purple, brown, and blue. Additionally, these pigments have a broad spectrum of pharmacological activities, including immunomodulatory, anticancer, antioxidant, antibacterial, and antiproliferative activities. This review provides an in-depth overview of fungi gathered from diverse sources and lists several probable fungi capable of producing a variety of color hues. The second section discusses how to classify coloring compounds according to their chemical structure, characteristics, biosynthetic processes, application, and present state. Once again, we investigate the possibility of employing fungal polyketide pigments as food coloring, as well as the toxicity and carcinogenicity of particular pigments. This review explores how advanced technologies such as metabolic engineering and nanotechnology can be employed to overcome obstacles associated with the manufacture of mycotoxin-free, food-grade fungal pigments.

Natural edible pigments: A comprehensive review of resource, chemical classification, biosynthesis pathway, separated methods and application

Natural edible pigments, high safety and low toxicity, usually possess various nutritional and pharmacological effects, and they have huge practical application value in the market. However, until now, there is no systematic review about the resources, chemical classifications and application about them. Moreover, the extracted methods and biosynthesis pathways which are very important informations for obtaining high-yield and high-purity natural edible pigments from natural resources are still lacking. Therefore, It is necessary to make a comprehensive review of natural edible pigments. In this work, we systematically summarize the resources, chemical classifications, biosynthesis pathways, extraction and separation methods, as well as application of natural edible pigments for the first time. Our work will provide reference data and give the inspiration for further industrial application of natural edible pigments.

Production of Natural Pigments by Penicillium brevicompactum Using Agro-Industrial Byproducts

The demand for natural pigments for industrial applications has significantly increased. Penicillium brevicompactum was recently reported as a promising pigments producer using submerged fermentation and a synthetic culture medium containing lactose. In this work, pigment production by P. brevicompactum was studied under different fermentation conditions, namely, submerged fermentation with free (SmF) and immobilized mycelium (SmFi), and solid-state fermentation (SSF). The potential of culture media composed of agro-industrial byproducts (cheese-whey (CW) and corn steep liquor (CSL)) was investigated for the first time as low-cost alternatives to pigment production by P. brevicompactum. The fungus showed great adaptability to the different culture media and types of fermentation, being able to synthesize pigments under all the tested conditions. A culture medium composed of 34.6 g/L of CW and 8 g/L of CSL proved to be the most suitable alternative to the synthetic medium, especially under SmF and SmFi. Our data also show that different mixtures of pigments (yellow, orange, and red) can be produced depending on the medium composition and the type of fermentation. Additionally, the immobilization and reuse of biomass to produce pigments by P. brevicompactum were demonstrated for the first time, suggesting the possibility of operating under repeated batch mode at an industrial scale.

Melanin of fungi: from classification to application

Melanin is a secondary metabolite composed of complex heterogeneous polymers. Fungal melanin is considered to be a sustainable and biodegradable natural pigment and has a variety of functional properties and biological activities. On one hand, due to its own specific properties it can play the role of antioxidant, anti-radiation, adsorption, and photoprotection. On the other hand, it has good biological activities such as hepatoprotective effect, hypolipidemic effect and anti-cancer. Therefore, it is widely used in various fields of daily life, including dyeing, food, biomedical and commercial industry. It is conducive to environmental protection and human health. However, the insolubility of fungal melanin in water, acids and organic solvents has been an obstacle to its commercial applications. Thus, the chemical modification methods of fungal melanin are summarized to increase its solubility and expand the application fields. Although fungal melanin has been used in many industries, as the structure and function of fungal melanin and modified melanin are further studied, more functional properties and bioactivities are expected to be discovered for a wide range of applications in the future.