Vijay Kumar

In this study, white-rot fungus, Rigidoporus vinctus, collected from an unidentified fallen twig from Pathankot, Punjab, India, was used for biosorption of anionic Congo red and cationic Methylene blue dyes from an aqueous medium. The biosorption efficiency of the live biomass of Rigidoporus vinctus was investigated to optimize biosorbent dosage, process time, concentrations of dyes, and pH of solutions. The results indicated that Rigidoporus vinctus is more efficient than other reported bio-adsorbents for Congo red and Methylene blue dyes. The maximum biosorption activity of Rigidoporus vinctus for Congo red was found at pH 2, and that for Methylene blue was at pH 10, after 24 h of the reaction period. The process followed pseudo-second-order kinetics, which indicated that the interaction of both dyes to the adsorption sites on the surface of Rigidoporus vinctus was responsive to biosorption. The biosorption process could be well explained by the Langmuir isotherm for both dyes. The maximum monolayer biosorption capacity of Rigidoporus vinctus for Congo red and Methylene blue was observed to be 54.0 mg/g and 80.6 mg/g, respectively. The seed germination test was carried out, and it was assessed that the toxicity of dyes was reduced up to significant levels. Based on the present experimental findings, it can be concluded that biosorption using the live biomass of Rigidoporus vinctus can effectively decolorize dye-containing wastewater, thus reducing the hazardous effects of dyes on human beings.

Endophytic fungi live symbiotically inside plants and are hidden source of natural bioactive molecules. The present study was carried out to investigate the phytochemical analysis and antioxidant activity of endophytic fungi isolated from the ethnomedicinal plant Dillenia indica L. The ethyl acetate crude extracts of the endophytic fungal strains were preliminarily evaluated for their phytochemical analysis, and the results showed the presence of alkaloids, flavonoids, phenolics, terpene, and saponins. The crude extracts of more than 60% of the isolates showed 50–90% antioxidant activity by DPPH and H₂O₂ assay. The inhibition percentage of ethyl acetate extracts ranges from 34.05 to 91.5%, whereas IC₅₀ values vary from 72.2 to 691.14%. Among all the strains, Fomitopsis meliae crude extract showed a maximum inhibition percentage, i.e., 91.5%, with an IC₅₀ value of 88.27 µg/mL. Chaetomium globosum showed significant activity having an inhibition percentage of 89.88% and an IC₅₀ value of 74.44 µg/mL. The total phenolic and flavonoid content in the crude extract of Chaetomium globosum was 37.4 mg gallic acid equivalent (GAE)/g DW and 31.0 mg quercetin equivalent (GAE)/g DW. GC–MS analysis of crude extract of C. globosum revealed different compounds, such as squalene; butanoic acid, 2-methyl-; hexadecanoic acid; 2-propanone, 1-phenyl-; 5-oxo-pyrrolidine-2-carboxylic acid methyl ester; 9,12-octadecadienoic acid (z)- etc. Many of these belong to phenolics, which are natural antioxidant compounds. The findings suggested that endophytic fungi associated with Dillenia indica L. can be a potential source of novel antioxidant compounds.

Medicinal plants are an important source of bioactive compounds and have been used to isolate various bioactive compounds having industrial applications. The demand for plants derived bioactive molecules is increasing gradually. However, the extensive use of these plants to extract bioactive molecules has threatened many plant species. Moreover, extracting bioactive molecules from these plants is laborious, costly, and time‐consuming. So, some alternative sources and strategies are urgently needed to produce these bioactive molecules similar to that of plant origin. However, the interest in new bioactive molecules has recently shifted from plants to endophytic fungi because many fungi produce bioactive molecules similar to their host plant. Endophytic fungi live in mutualistic association within the healthy plant tissue without causing disease symptoms to the host plant. These fungi are a treasure house of novel bioactive molecules having broad pharmaceutical, industrial, and agricultural applications. The rapid increase in publications in this domain over the last three decades proves that natural product biologists and chemists are paying great attention to the natural bioactive products from endophytic fungi. Though endophytes are source of novel bioactive molecules but there is need of advanced technologies like clustered regularly interspaced short palindromic repeats and CRISPR‐associated protein 9 (CRISPR‐Cas9) and epigenetic modifiers to enhance the production of compounds having industrial applications. This review provides an overview of the various industrial applications of bioactive molecules produced by endophytic fungi and the rationale behind selecting specific plants for fungal endophyte isolation. Overall, this study presents the current state of knowledge and highlights the potential of endophytic fungi for developing alternative therapies for drug‐resistant infections.

The current study was carried out under laboratory conditions to estimate developmental parameters of P. gossypiella on various hosts viz., G. hirsutum (BG II, Bt and non-Bt cotton), G. arboreum (desi cotton) and Abelmoschus esculentus L. (okra). The findings revealed its shortest larval period on okra and longest on non-Bt cotton. The fecundity was significantly high on non-Bt and BG II cotton. Larval and pupal weight and survival period were lower on BG II cotton while they were highest on non-Bt cotton. Amongst the various host plants studied, non-Bt cotton was a preferable host in terms of fecundity, larval duration, larval and pupal weight and survival. Further, BG II and desi cotton showed most negative effects on biological parameters of P. gossypiella.

Plants form associations with different microbes; some promote their growth and protect from biotic and abiotic stresses in different ways. However, the biological role of fungi associated with the rhizosphere of medicinal plants is not well explored. In the present study, Colletotrichum gloeosporioides, and Aspergillus fumigatus isolated from the rhizosphere of Dillenia indica were screened for their phosphate solubilization and indole-3-acetic acid (IAA) production potential. The selected fungal strains were identified by macroscopic, microscopic, and molecular characteristics. Phosphate solubilization was qualitatively and quantitatively evaluated using Pikovskaya’s (PVK) agar and PVK broth medium using different substrates such as AlPO₄, Ca₃(PO₄)₂, and FePO₄. Colletotrichum gloeosporioides and Aspergillus fumigatus with respect to the phosphate source showed solubilization index (SI) of 1.7 ± 0.03 and 2.1 ± 0.04, and solubilized phosphate up to 138.8 ± 0.058 µg/mL and 121.6 ± 0.062 µg/mL. These fungal strains are also good producers of IAA and significantly enhance the growth of Vigna radiata and Cicer arietinum seedlings. This is the first report on A. fumigatus and C. gloeosporioides from the rhizosphere of Dillenia indica and their phosphate solubilization and IAA production ability.

Endophytes are microbes that live inside the tissues of plants without causing any disease. Many of these belonging to fungi have been exploited earlier for their biological activities. This study focused on the exploration and characterization of culturable endophytic fungi inhabiting the medicinal plant Dillenia indica l. during four different seasons (summer, monsoon, autumn, and winter) from 2018 to 2019. A total of 2360 segments from different parts (leaves, fruits, and stem) were screened to isolate endophytic fungi. During the study, 25 species of fungi belonging to 20 genera were isolated from the selected plant. The identification of these fungi was validated at morphological, microscopic, and molecular levels. Results indicate the plant has the highest affinity for Daldinia eschscholtzii, followed by Colletotrichum gloeosporioides and Cladosporium cladosporioides. Further, the percent frequency was highest in leaves, followed by stem and fruits. The results were further supported by a similar trend of colonization rate for different plant parts. The monsoon season had the highest number of isolates (312), followed by summer (208), winter (164), and autumn (114). Species diversity was highest during the monsoon season and lowest during the winter. These fungi also produce amylase, lipase, protease, asparaginase, cellulase, and ligninolytic enzymes. This study focused only on culturable fungal endophytes, yet the scope can be extended for other non-culturable microbes and their interaction by using high-throughput genomics and novel next-generation sequencing (NGS) tools. The results indicate that Dillenia indica l. harbors novel endophytic fungi having industrial applications.

The present study evaluated the antibacterial potential of endophytic fungi isolated from Dillenia indica L. and identified bioactive compounds responsible for their antimicrobial activity. A total of twenty-five endophytic fungi were preliminarily screened for their antibacterial activity against human pathogenic bacteria, i.e., Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Bacillus subtilis by dual culture assay. The strains having antibacterial activity were selected and crude extracts were prepared from them. The crude extracts were screened for antibacterial activity by agar well diffusion assay. The ethyl acetate extract of Fomitopsis meliae showed the highest activity against selected human pathogenic bacteria, with a zone of inhibition ranging from 15 to 29 mm. The Gas chromatography-Mass spectrometry (GC-MS) analysis of the ethyl acetate extract of F. meliae showed the presence of 40 compounds with predominance of Dodecane (8.87%), Ethyl 2-thiopheneacetate (4.12%), Tetradecane (13.86%), Hexadecane (12.05%), Octadecane (6.67%), Benzaldehyde, 4-(1-methylethyl)- (10.83%), Griseofulvin (3.31%). Graphical Abstract