Chemical Profiling, Bioactivity Evaluation and the Discovery of a Novel Biopigment Produced by Penicillium purpurogenum CBS 113139

Fungi-derived natural antioxidants

In humans, exogenous antioxidants aid the endogenous antioxidant system to detoxify excess ROS generated during oxidative stress, thereby protecting the body against various diseases and stressful conditions. The majority of natural antioxidants available on the consumer market are plant-based; however, fungi are being recognized as alternative sources of various natural antioxidants such as polysaccharides, pigments, peptides, sterols, phenolics, alkaloids, and flavonoids. In addition, some exogenous antioxidants are exclusively found in fungi. Fungi-derived antioxidants exhibit scavenging activities against DPPH, ABTS, hydroxyl, superoxide, hydrogen peroxide, and nitric oxide radicals in vitro. Furthermore, in vivo models, application of fungal-derived antioxidants increase the level of various antioxidant enzymes, such as catalases, superoxide dismutases, and glutathione peroxidases, and reduce the level of malondialdehyde. Therefore, fungi-derived antioxidants have potential to be used in the food, cosmetic, and pharmaceutical industries. This review summarizes the antioxidant potential of different fungi (mushrooms, yeasts, and molds)-derived natural compounds such as polysaccharides, pigments, peptides, ergothioneine, ergosterol, phenolics, alkaloids, etc.

Production of Pigments under Submerged Culture through Repeated Batch Fermentation of Immobilized Talaromyces atroroseus GH2

Pigments of natural origin have become a research trend, and fungi provide a readily available alternative source. Moreover, developing novel processes that increase yields, reduce process time and simplify downstream processing is of increased interest. In this sense, this work proposes an alternative for Talaromyces atroroseus GH2 biomass re-utilization to produce pigments through consecutive batches using immobilized mycelium. Different support materials were evaluated for pigment production and immobilization capacity. Then, Taguchi’s method was applied to determine the effect of four factors related to fungal immobilization and pigment production (inoculum concentration, support density, working volume and support volume). Afterward, process kinetics for pigment production using immobilized cells of T. atroroseus GH2 in consecutive batches were evaluated. All evaluated factors were significant and affected pigment production and microorganism growth differently. At improved conditions, immobilization capacity reached 99.01 ± 0.37% and the pigment production was 30% higher than using free cells. Process kinetics showed that the production could continue for three batches and was limited by excessive microorganism growth. Indeed, more studies are still needed, but the immobilization of Talaromyces atroroseus GH2 represents a promising strategy for allowing downstream-processing intensification since immobilized biomass is easily removed from the fermentation media, thus paving the way for the further development of a continuous process.

A new endophyte Monascus ruber SRZ112 as an efficient production platform of natural pigments using agro-industrial wastes

A number of biopigment applications in various industrial sectors are gaining importance due to the growing consumer interest in their natural origin. Thus, this work was conducted to valorize endophytic fungi as an efficient production platform for natural pigments. A promising strain isolated from leaves of Origanum majorana was identified as Monascus ruber SRZ112 produced several types of pigments. The nature of the pigments, mainly rubropunctamine, monascin, ankaflavin, rubropunctatin, and monascorubrin in the fungal extract was studied by LC/ESI–MS/MS analyses. As a first step towards developing an efficient production of red pigments, the suitability of seven types of agro-industrial waste was evaluated. The highest yield of red pigments was obtained using potato peel moistened with mineral salt broth as a culture medium. To increase yield of red pigments, favourable culture conditions including incubation temperature, incubation period, pH of moistening agent, inoculum concentration, substrate weight and moisture level were evaluated. Additionally, yield of red pigments was intensified after the exposure of M. ruber SRZ112 spores to 1.00 KGy gamma rays. The final yield was improved by a 22.12-fold increase from 23.55 to 3351.87 AU g⁻¹. The anticancer and antioxidant properties of the pigment’s extract from the fungal culture were also studied. The obtained data indicated activity of the extract against human breast cancer cell lines with no significant cytotoxicity against normal cell lines. The extract also showed a free radical scavenging potential. This is the first report, to our knowledge, on the isolation of the endophytic M. ruber SRZ112 strain with the successful production of natural pigments under solid-state fermentation using potato peel as a substrate.

Optimization, purification, and structure elucidation of Anthraquinone pigment derivative from Talaromyces purpureogenus as a novel promising antioxidant, anticancer, and kidney radio-imaging agentAnthraquinone pigment as a promising antioxidant, anticancer, and radio-imaging agent

This study aims to investigate the bioproduction and prospective biological applications of a natural red pigment from Talaromyces purpureogenus AUMC2603. Maximum pigment yield was achieved by a numerical optimization at pH 6, temperature 25°C, and an 18-day incubation period on Yeast Malt Broth (YMB) media. The crude pigment was separated and purified into two pigment fractions via solid-phase extraction and then characterized as anthraquinone (dominant) and herquinone by LC/MS and ¹HNMR analysis. The crude pigment extract and the two separated fractions displayed a potential antioxidant activity. Additionally, they showed a powerful anticancer activity towards cancer cell lines, MCF-7, HepG-2, and HCT116 with less cytotoxicity on normal cell lines, MCF12F and BJ-1T. The radioiodination efficiency of the radiosynthesized ^99mTc-anthraquinone pigment complex was also investigated and optimized, obtaining a radiochemical yield of 92.70% ± 0.89%. An in vivo biodistribution study of the ^99mTc-anthraquinone pigment complex demonstrated a high kidney uptake of 34% injected dose per gram of organ tissue 60min after intravenous injection, and the complex retention remained high up to 120min. The current study is the first bioassay report on the efficacy of a purified anthraquinone from T. purpureogenus as a potent agent for kidney radio-imaging that could be applied in kidney cancer diagnosis.

Endophytic community of Chaenomeles speciosa fruits: Screening for biodiversity and antifungal activity

Fruit crops of the genus Chaenomeles Lindl are considered today as a superfood due to accumulation of biologically active compounds with antioxidant ability and known health-promoting properties. Successful introduction of this non-traditional culture in the steppe zone of Ukraine characterised by an unfavourable climate suggests the functioning of effective protective mechanisms in plants, including those that can be provided by the influence of endophytic microorganisms. However, there is little information about the endophytic community of Chaenomeles plants. Herein, the current study was aimed to isolate the endophytic fungi from the Ch. speciosa fruits and evaluate their biological activities against the phytopathogens. The study was carried out based on the collection of the Botanical Garden of Oles Honchar Dnipro National University (Dnipro city, Ukraine). Three media, namely PDA, MPA, and Gause’s medium were used for isolation of endophytic fungi. Colonies of isolates for identification were grown on PDA, Czapek's agar, and Czapek’s yeast autolysate media. Six fungal endophytic isolates derived from both peel and pulp of Ch. speciosa fruits have been morphologically identified using macroscopic and microscopic techniques, and assigned to the genus Penicillium (sections Chrysogena, Penicillium, Viridicata), and genus Talaromyces (section Talaromyces). Species P. expansum, P. viridicatum, and P. hirsutum were identified among the peel isolates, while P. chrysogenum, P. cyclopium, and P. purpurogenum were among the pulp isolates. Antagonistic ability of the endophytic isolates against phytopathogenic fungi was evaluated using the dual culture method. The results showed moderate to high antifungal capacity of the endophytic isolates against the phytopathogenic strains of the Fusarium genus. The growth inhibition of F. culmorum mycelium due to the influence of endophytic isolates was 51.5–81.3%, and the inhibition of the growth of F. oxysporum colonies was in the range of 68.4–86.6% as compared with control. There were no significant differences in the antagonistic ability between endophytic isolates derived from the peel and pulp of the fruit. Taken together, our findings indicated the great potential of the endophytic fungi from Ch. speciosa fruits as a source for the development of biocontrol agents and discovery of new bioactive compounds.