Suvendu Manna

The growing demand for natural pigment sources is driven by increasing concerns about environmental preservation and human health. Microbial pigments, with their higher bioactivity, offer a range of beneficial properties such as antimicrobial, antitumor, and antiallergic activities, making them valuable for pharmaceutical applications. In this study, pigment-producing metabolites from endophytic bacteria were isolated from Mentha piperita leaves using enrichment culture techniques. The isolated bacterial strain was identified as Pseudomonas sp. Anjali MT-02 (Accession number PQ098594). The production of pigments was optimized through response surface methodology, with factors such as pH, temperature, incubation time, and inoculum size being varied. The highest pigment production occurred when the bacteria were cultured at 35 °C for 96 h at pH 6.4, with an inoculum size of 3.3 mL/100 mL. UV-Visible spectra revealed a maximum absorption at 636 nm. Additionally, the pigments demonstrated excellent dyeing potential on cotton fabric, indicating their suitability for various applications. Also, PSM showed almost three times more inhibition zone against both gram positive and gram negative bacterial strains. Also, PSM showed non-toxic to rat fibroblast cells. These results suggested that PSM have potential to use for biomedical application. This research highlights the potential of utilizing endophytic bacteria for sustainable, high-value pigment production, with significant implications for microbial biotechnology and natural product synthesis.

This study focused on the green synthesis of phytochemical-coated ZnONPs for biomedical applications. Standard in vitro assay confirms excellent antibacterial potential of ZnONPs, which was well supported by the in silico study.

Endophytes have significant prospects for applications beyond their existing utilization in agriculture and the natural sciences. They form an endosymbiotic relationship with plants by colonizing the root tissues without detrimental effects. These endophytes comprise several microorganisms, including bacteria and fungi. They act as repositories of compounds of medicinal importance. They are considered sources of pigments besides synthetic dyes and assist with soil fertility and plant growth as bio-fertilizers. They also have immense potential for advanced technology using endophyte-synthesized nanoparticles. In assisting bioremediation, they facilitate detoxification of pollutants in all spheres of the environment. Studies on the potential of endophytic microbes in drug discovery and biotic stress management are underway. In this review, published databases on endophytes and their diverse roles and applications in various fields, such as bio-fertilizers and nanoparticles, as well as bioremediation, are critically discussed while exploring unanswered questions. In addition, future perspectives on endosymbiotic microorganisms and their prospective use in plants, environmental management, and medicine are discussed in this review. Graphical abstract

Background: Papaya leaves (PLs) are known for their therapeutic benefits and traditional use in treating inflammation, infections, and various health conditions. Rich in bioactive compounds, PLs are studied for their potential applications in functional foods. This study analyzed their nutritional, phytochemical, structural, thermal, and antimicrobial properties to evaluate their role as a health-promoting ingredient. Methods: Phytochemicals were quantified spectrophotometrically and identified via GC-MS. Antioxidant activity was assessed using DPPH and FRAP assays. Mineral content was determined using ICP-OES. Structural and thermal properties were evaluated using FTIR, XRD, and calorimetry, and antimicrobial activity was tested via the agar well diffusion method. Results: PLs contained 25.75% crude protein, 41.49% carbohydrates, and high levels of flavonoids (21.00 mg QE/g), phenolics (8.85 mg GAE/g), and tannins (430 mg TAE/g). Antioxidant assays confirmed strong free radical scavenging potential. Mineral analysis showed abundant K, Ca, Mg, Na, and Fe (4071, 1079, 789.2, 361.2, and 228.2 mg/kg, respectively). Structural and thermal analysis revealed bioactive functional groups, 23.9% crystallinity, and thermal degradation characteristics. PLs exhibited antimicrobial activity, inhibiting E. coli, S. aureus, B. subtilis, and K. pneumoniae with zones of 22.05–25.15 mm. Conclusions: PLs demonstrate strong nutritional, antioxidant, and antimicrobial properties, supporting their inclusion in functional food.