Characterization of an Endophytic Strain Talaromyces assiutensis, CPEF04 With Evaluation of Production Medium for Extracellular Red Pigments Having Antimicrobial and Anticancer Properties

Genome Characteristics of the Endophytic Fungus Talaromyces sp. DC2 Isolated from Catharanthus roseus (L.) G. Don

Talaromyces sp. DC2 is an endophytic fungus that was isolated from the stem of Catharanthus roseus (L.) G. Don in Hanoi, Vietnam and is capable of producing vinca alkaloids. This study utilizes the PacBio Sequel technology to completely sequence the whole genome of Talaromyces sp. DC2The genome study revealed that DC2 contains a total of 34.58 Mb spanned by 156 contigs, with a GC content of 46.5%. The identification and prediction of functional protein-coding genes, tRNA, and rRNA were comprehensively predicted and highly annotated using various BLAST databases, including non-redundant (Nr) protein sequence, Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), Clusters of Orthologous Groups (COG), and Carbohydrate-Active Enzymes (CAZy) databases. The genome of DC2 has a total of 149, 227, 65, 153, 53, and 6 genes responsible for cellulose, hemicellulose, lignin, pectin, chitin, starch, and inulin degradation, respectively. The Antibiotics and Secondary Metabolites Analysis Shell (AntiSMASH) analyses revealed that strain DC2 possesses 20 biosynthetic gene clusters responsible for producing secondary metabolites. The strain DC2 has also been found to harbor the DDC gene encoding aromatic L-amino acid decarboxylase enzyme. Conclusively, this study has provided a comprehensive understanding of the processes involved in secondary metabolites and the ability of the Talaromyces sp. DC2 strain to degrade plant cell walls.

Application of microbial resources in biorefineries: Current trend and future prospects

The recent growing interest in sustainable and alternative sources of energy and bio-based products has driven the paradigm shift to an integrated model termed "biorefinery." Biorefinery framework implements the concepts of novel eco-technologies and eco-efficient processes for the sustainable production of energy and value-added biomolecules. The utilization of microbial resources for the production of various value-added products has been documented in the literatures. However, the appointment of these microbial resources in integrated resource management requires a better understanding of their status. The main of aim of this review is to provide an overview on the defined positioning and overall contribution of the microbial resources, i.e., algae, fungi and bacteria, for various bioprocesses and generation of multiple products from a single biorefinery. By utilizing waste material as a feedstock, biofuels can be generated by microalgae while sequestering environmental carbon and producing value added compounds as by-products. In parallel, fungal biorefineries are prolific producers of lignocellulose degrading enzymes along with pharmaceutically important novel products. Conversely, bacterial biorefineries emerge as a preferred platform for the transformation of standard cells into proficient bio-factories, developing chassis and turbo cells for enhanced target compound production. This comprehensive review is poised to offer an intricate exploration of the current trends, obstacles, and prospective pathways of microbial biorefineries, for the development of future biorefineries.

Isolation and characterization of a newly discovered plant growth-promoting endophytic fungal strain from the genus Talaromyces

In the Kandi zone of Punjab, India, root and rhizospheric soil samples were collected from the local vegetation near the Shivalik mountain foothills. Fifteen fungal colonies exhibiting distinct cultural morphology on Potato Dextrose Agar (PDA) plates were selected for plant-microbe interaction studies. Among these, the isolate HNB9 was identified as a nonpathogenic root colonizer. Morphological and molecular analyses confirmed HNB9 as Talaromyces albobiverticillius, characterized by the secretion of a red pigment as a secondary metabolite. Plants colonized with T. albobiverticillius HNB9 exhibited enhanced growth, manifesting in increased shoot and root length compared to untreated controls. This study unveiled the first evidence that a species from the Talaromyces genus, specifically T. albobiverticillius, possesses dual capabilities of root colonization and plant growth promotion. Moreover, HNB9 demonstrated the production of plant growth-regulating compounds like Indole Acetic Acid (IAA) and proficient solubilization of crucial nutrients (Phosphorous, Zinc, and Silica) through plate culture methods. This finding represents a significant contribution to the understanding of root-colonizing fungi with plant growth-promoting attributes, challenging the existing knowledge gap within the Talaromyces genus.

Talaromyces sedimenticola sp. nov., isolated from the Mariana Trench

Two fungal strains (K-2T and S1) were isolated from the deepest ocean sediment of the Challenger Deep located in the Mariana Trench. The internal transcribed spacer (ITS) gene sequences of the isolates K-2T and S1 differed from those of closely related species, such as Talaromyces assiutensis and T. trachyspermus. Phylogenetic analyses based on single and concatenated alignments of the genes, namely ITS, β-tubulin (benA), calmodulin (cam), and the second-largest subunit fragment of the RNA polymerase II (rpb2) showed that the isolates K-2T and S1 were clustered together with other Talaromyces species, such as T. trachyspermus and T. assiutensis, as evidenced by the position on a terminal branch with high bootstrap support. They could also be distinguished from their closest relatives with valid published names via morphological and physiological characteristics, for example, growth at 4 °C-50 °C with a pH in the range of 1.5-12. Based on their phylogenetic, morphological, and physicochemical properties, the isolates K-2T and S1 represent a novel species in the genus Talaromyces, and the proposed name is Talaromyces sedimenticola sp. nov. The type strain is K-2T (= GDMCC 3.746T = JCM 39451T).

Electrospun polylactic acid nanofiber film modified by silver oxide deposited on hemp fibers for antibacterial fruit packaging

Bacterial and fungal contamination have become major factors in fruit spoilage and damage, posing a potential risk to human health. In this work, polylactic acid (PLA) nanofibers combined with Ag2O-hemp fibers for a good antimicrobial effect were developed and applied to antimicrobial fruit fresh-keeping packages. The results of molecular simulation calculations showed that the strength of hydrogen bonds between Ag2O and hemp fibers reached 45.522 kJ·mol-1, which proved that Ag2O and with hemp fibers formed a stable deposition. The Ag2O-hemp fibers modified electrospun polylactic acid nanofibrous composite film exhibited favorable mechanical properties. The tensile strength reached 5.23 ± 0.05 MPa and the elongation at break reached 105.56 ± 3.95 %. The obtained nanofibrous composite film has good antibacterial activity against E. coli, S. aureus, A. niger, and Penicillium, which indicated that they could effectively inhibit the growth of bacteria and fungi. The cell experiments proved that the nanofibrous composite film had good biocompatibility with a cell survival rate of 100 %. The experimental results on the fresh-keeping of red grapes showed that the PLA nanofibrous composite film modified by the Ag2O-hemp fibers could effectively prolong the spoilage time of red grapes at room temperature. Compared with the blank group, the freshness period of PLA nanofiber film modified by Ag2O-hemp fibers could be extended for more than 5 days. The hardness of 15 days (1.94 ± 0.19 × 105 Pa) was basically the same as that of 1 day (2.05 ± 0.06 × 105 Pa). The results were superior to commercially available PE preservation films. The above research results indicated that the Ag2O-hemp fibers modified PLA nanofibrous composite film had potential application prospects in the field of fruit fresh-keeping package.

In-vitro investigation on the biological activities of squalene derived from the soil fungus Talaromyces pinophilus

The consistent increase in multidrug resistance among pathogens and increased cancer incidence are serious public health concerns and threaten humans by killing countless lives. In the present study, Talaromyces pinophilus CJ15 was characterized and evaluated for its antibacterial, candidicidal and cytotoxic activities. The selected isolate Talaromyces pinophilus CJ15 with 18S rRNA gene sequence of 1021 base pairs exhibited antifungal activity on plant pathogens via dual culture. The GC-MS profiling of crude extract illustrated the existence of many bioactive macromolecules which include squalene belonging to the terpenoids family. The biological macromolecules in the bioactive fraction of CJ15 exhibited increasing antibacterial activity with an increase in concentration such that the highest activity was recorded against Shigella flexneri with 15, 18, 20, and 24 mm inhibition zones at 25, 50, 75 and 100 μl concentrations, respectively. The squalene, having a molecular weight of 410.718 g/mol, displayed candidicidal activity with a right-side shifted log phase in the growth curve of all the treated Candida species, indicating delayed exponential growth. In cytotoxic activity, the extracted squalene exhibited an IC50 concentration of 26.22 μg/ml against JURKAT cells and induced apoptosis-induced cell death. This study's outcomes encourage the researchers to explore further the development of new and improved bioactive macromolecules that could help to prevent infections and human blood cancer.

Endophytic fungi: hidden treasure chest of antimicrobial metabolites interrelationship of endophytes and metabolites

Endophytic fungi comprise host-associated fungal communities which thrive within the tissues of host plants and produce a diverse range of secondary metabolites with various bioactive attributes. The metabolites such as phenols, polyketides, saponins, alkaloids help to mitigate biotic and abiotic stresses, fight against pathogen attacks and enhance the plant immune system. We present an overview of the association of endophytic fungal communities with a plant host and discuss molecular mechanisms induced during their symbiotic interaction. The overview focuses on the secondary metabolites (especially those of terpenoid nature) secreted by endophytic fungi and their respective function. The recent advancement in multi-omics approaches paved the way for identification of these metabolites and their characterization via comparative analysis of extensive omics datasets. This study also elaborates on the role of diverse endophytic fungi associated with key agricultural crops and hence important for sustainability of agriculture.

The Outstanding Chemodiversity of Marine-Derived Talaromyces

Fungi in the genus Talaromyces occur in every environment in both terrestrial and marine contexts, where they have been quite frequently found in association with plants and animals. The relationships of symbiotic fungi with their hosts are often mediated by bioactive secondary metabolites, and Talaromyces species represent a prolific source of these compounds. This review highlights the biosynthetic potential of marine-derived Talaromyces strains, using accounts from the literature published since 2016. Over 500 secondary metabolites were extracted from axenic cultures of these isolates and about 45% of them were identified as new products, representing a various assortment of chemical classes such as alkaloids, meroterpenoids, isocoumarins, anthraquinones, xanthones, phenalenones, benzofurans, azaphilones, and other polyketides. This impressive chemodiversity and the broad range of biological properties that have been disclosed in preliminary assays qualify these fungi as a valuable source of products to be exploited for manifold biotechnological applications.

Valorization of pineapple peel waste for fungal pigment production using Talaromyces albobiverticillius: Insights into antibacterial, antioxidant and textile dyeing properties

The present study explores natural pigments as sustainable alternatives to synthetic textile dyes. Due to their therapeutic applications and easy production, fungal pigments have gained attention. However, data on pigment production using solid-state fermentation and optimization is limited. Milk whey was used to grow Talaromyces sp., followed by an evaluation of pigment production in solid and liquid media. Pineapple peels were used as a cost-effective substrate for pigment production, and a one-factor-at-a-time approach was used to enhance pigment production. Pineapple peel-based media produced 0.523 ± 0.231 mg/g of pigment after eight days of incubation. The crude pigment had promising antibacterial and significant antioxidant properties. The extraction fungal pigment's possible use as an eco-friendly textile dye was assessed through fabric dyeing experiments with different mordants. This work contributes to the valorization of agricultural waste and provides insight into using fungal pigments as sustainable alternatives to synthetic textile dyes.

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.

Characterization of the Red Biochromes Produced by the Endophytic Fungus Monascus purpureus CPEF02 with Antimicrobial and Antioxidant Activities

Food acceptability and appeal are significantly influenced by colour. Harmful effects associated with synthetic colorants are well established, and research is currently focused on developing natural, synthetic chemical-free substitutes from fungal sources, with broad applications in food, medicine, textiles and agriculture. Additionally, the market’s dearth of natural red colour substitutes requires the creation of novel red pigment alternatives from secure and scalable sources. The goal of the current research was to establish new endophytic marine fungi that are naturally occurring bio-sources of the red pigment. Based on its profuse extracellular red pigment-producing capacity, the fungus CPEF02 was selected and identified as Monascus purpureus CPEF02 via internal transcribed spacer (ITS) sequences and phylogenetic analysis. The chemical moieties of the pigmented extracts were identified by liquid chromatography-high resolution mass spectrometry (LC-HRMS). The optimal culture conditions for maximum pigment production were investigated by surveying various media compositions. The methanolic fungal colourant extract was shown to have substantial antibacterial and antifungal activities against anthropogenic pathogens, Staphylococcus aureus (MTCC 1430), methicillin-resistant Staphylococcus aureus (ATCCBAA811), Salmonella typhimurium (MTCC 3241) and Vibrio cholerae (N16961) at a 100 µg/mL concentration and at a 1 mg/mL concentration for Alternaria solani (ITCC 4632) and Rhizoctonia solani (AG1-IA). This extract also exhibited antioxidant activity against the 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical with an IC50 of 14.42 µg/mL and a Trolox equivalent antioxidant capacity of 0.571 µM Trolox/µg of the methanolic colourant extract. The findings suggested that M. purpureus’s pigment could be a source of an industrially useful natural red colourant.

Bio-Synthesis of Aspergillus terreus Mediated Gold Nanoparticle: Antimicrobial, Antioxidant, Antifungal and In Vitro Cytotoxicity Studies

Gold nanoparticles (GNP) were bio-fabricated utilizing the methanolic extract of the endophytic isolate Aspergillus terreus. The biosynthesised gold nanoparticles (GNP023) were characterised using UV-visible spectroscopy (UV-Vis); transmission electron microscopy (TEM), Fourier-transform nfrared spectroscopy (FTIR) and X-ray diffraction (XRD) studies. The bio-fabricated GNP023 displayed a sharp SPR peak at 536 nm, were spherically shaped, and had an average size between 10–16 nm. The EDX profile confirmed the presence of gold (Au), and XRD analysis confirmed the crystalline nature of GNP023. The antimicrobial activity of GNP023 was investigated against several food-borne and phytopathogens, using in vitro antibacterial and antifungal assays. The maximum zone of inhibition was observed for S. aureus and V. cholera at 400 μg /mL, whereas inhibition in radial mycelial growth was observed against Fusarium oxysporum and Rhizoctonia solani at 52.5% and 65.46%, respectively, when challenged with GNP023 (200 μg/mL). Moreover, the gold nanoparticles displayed significant antioxidant activity against the ABTS radical, with an IC₅₀ of 38.61 µg/mL, and were non-toxic when tested against human kidney embryonic 293 (HEK293) cells. Thus, the current work supports the application of myco-synthesised gold nanoparticles as a versatile antimicrobial candidate against food-borne pathogens.

New Antibacterial Secondary Metabolites from a Marine-Derived Talaromyces sp. Strain BTBU20213036

New polyketide-derived oligophenalenone dimers, bacillisporins K and L (1 and 2) and xanthoradone dimer rugulosin D (3), together with four known compounds, bacillisporin B (4), macrosporusone D (5), rugulosin A and penicillide (6 and 7), were isolated from the marine-derived fungus Talaromyces sp. BTBU20213036. Their structures were determined by detailed analysis of HRESIMS, 1D and 2D NMR data, and the absolute configurations were determined on the basis of calculated and experimental electronic circular dichroism (ECD). The antibacterial and antifungal activities of these compounds were tested against Gram-positive—Staphylococcus aureus, Gram-negative—Escherichia coli, and fungal strain—Candida albicans. These compounds showed potential inhibitory effects against S. aureus with minimum inhibitory concentrations ranging from 0.195 to 100 µg/mL.