Elucidation of the composition, antioxidant, and antimicrobial properties of essential oil and extract from Citrus aurantifolia (Christm.) Swingle peel.

The most effective methodologies for generating Musa spp. explants involve the utilization of plant tissue culture micropropagation techniques. However, the pervasive challenge of microbial contamination significantly impedes the successful micropropagation of Musa spp. This study examined the antioxidant and antibacterial characteristics of the essential oil (LPO) and extract (LPE) obtained from the peel of Citrus aurantifolia. Additionally, we explored their mechanisms against common microbial contaminants in Musa spp. micropropagation. Using gas chromatography-mass spectrometry, we identified 28 components in LPO, with δ-limonene, ß-pinene, citral, trans-citral, ß-bisabolene, geranyl acetate, and α-pinene as the primary constituents. Meanwhile, liquid chromatography-mass spectrometry detected 17 components in LPE, highlighting nobiletin, tangeretin, scoparone, sinensetin, tetramethylscutellarein, 5-demethylnobiletin, and pyropheophorbide A as the predominant compounds. Evaluation using the DPPH and ABTS methods revealed the IC50 values for LPE at 0.66 ± 0.009 and 0.92 ± 0.012 mg/mL, respectively, indicating higher antioxidant activity compared to LPO, with IC50 values of 3.03 ± 0.019 and 4.27 ± 0.023 mg/mL using the same methods. Both LPO and LPE exhibited antimicrobial activities against all tested contaminant microorganisms through in vitro assays. Mechanistic investigations employing time-kill analysis, assessment of cell membrane integrity, and scanning electron microscopy (SEM) revealed changes in the morphological characteristics of the tested microbial contaminants, intensifying with increased concentration and exposure duration of LPO and LPE. These alterations led to substantial damage, including cell wall lysis, leakage of intracellular components, and subsequent cell death. Consequently, LPO and LPE emerge as promising alternatives for addressing microbial contamination in banana tissue cultures.

An optimized chitosan/alginate-based microencapsulation of lime peel essential oil and its application as an antibacterial textile.

A functional textile immobilized by microcapsules of the lime peel essential oils of C. aurantifolia (LPEO) was prepared and characterized. A varied amount of Chitosan/Alginate (CH/AG) ratios, followed by a mass of LPEO and concentration of sodium tripolyphosphate (STPP) crosslinker, was optimized sequentially to coacervate LPEO using a Tween 80 emulsifier. An antibacterial assay against both Gram-positive and Gram-negative bacteria was further evaluated for the embedded microcapsules. The LPEO (0.2 g) was effectively coacervated by CH/AG (5:3) crosslinked by 2% of STTP to give a yield, oil content (OC), and encapsulation efficiency (EE) of 53.45 ± 2.16%, 65.08 ± 2.60% and 85.04 ± 0.70% respectively. A rough spherical shape of LPEO microcapsules was homogeneously observed with an average particle size of 0.757 mm. An Avrami's kinetic model revealed the release mechanism of the core following zero-order kinetics (k = 1.11 ± 0.13 × 10-9 s-1, Ea = 70.21 kJ/mol). The LPEO microcapsules demonstrated good thermal stability up to 122 °C and maintained 38% OC at ambient temperature for four weeks. A 70.34 ± 4.16% of the LPEO microcapsules were successfully overlaid onto the gauze with citric acid binder and sodium phosphate catalyst. Overall, the immobilized microcapsules exhibited strong inhibition against S. aureus and moderate against S. epidermidis, E. coli, and K. pneumonia.

Effect of sucrose as an elicitor in increasing quercetin-3-O-rhamnoside (quercitrin) content of chrysanthemum (Chrysanthemum morifolium Ramat) callus culture based on harvest time differences.

Chrysanthemum (Chrysanthemum morifolium) contains secondary metabolites, such as flavonoid compounds, especially luteolin-7-glucoside and quercetin-3-O-rhamnoside (quercitrin), in its tissues. Utilizing sucrose as an elicitor through callus culture presents an alternative method to enhance the production of secondary metabolites. This research aimed to determine the best sucrose concentration and harvest time for maximizing quercitrin content in chrysanthemum callus culture. The research employed a completely randomized design with four treatment groups: 0, 30, 45, and 60 g/l of sucrose added to MS medium containing 4 ppm 2,4-dichlorophenoxyacetic acid (2,4-D). Callus samples were harvested on the 15th and 30th days of culture. The observed parameters included callus morphology (color and texture), fresh weight, dry weight, the diameter of the callus, and quercitrin content analyzed using high-performance liquid chromatography. The results showed that all callus cultures exhibited intermediate textures and varied colors, predominantly shades of brown. The treatment involving 45 g/l of sucrose with a 30th-day harvest yielded the highest fresh weight, dry weight, and quercitrin content, namely 2.108 g, 0.051 g, and 0.437 mg/g DW, respectively. Notably, the quercitrin content exhibited a 63.67% increase compared to the control.

Endophytic microbiome of Boehmeria nivea and their antagonism against latent fungal pathogens in plants.

BACKGROUND: Pathogenic microbes still become obstacles that can reduce the quality of plant growth, including ramie (Boehmeria nivea) plants. The study identified the microbiome and antagonistic interaction of the endophytic community from the B. nivea is necessary to improve the production of the ramie plant, especially ramie stem organs for fiber materials.  RESULTS: Twenty isolates of endophytic microorganisms were obtained from the roots, stems, leaves, and flowers. They were identified using the Internal Transcribed Spacer (ITS) region of ribosomal (rDNA), and its morphotypes obtained 20 isolates, with a composition of 9 species of bacteria and 11 species of fungi. Besides that, the disease observations on ramie stems showed that four species of pathogenic fungi were identified as Fusarium solani isolate 3,248,941, Fusarium solani isolates colpat-359, Fusarium oxysporum isolate N-61-2, Clonostachys rosea strain B3042. The endophytic microorganism of ramie ability was tested to determine their potential to inhibit the growth of the pathogenic fungi based on the in-vivo antagonist test. The isolated bacteria were only able to inhibit the growth of F. solani, with the highest percentage of 54-55%. Three species of endophytic fungi, including Cladosporium tennissimum, Fusarium falciforme, and Penicillium citrinum, showed the best inhibition against the fungal pathogen Fusarium solani with the highest inhibitory presentation of 91-95%. Inhibitory interaction between the endophytic microbes and the ramie pathogens indicated the type of antibiosis, competition, and parasitism.  CONCLUSION: The results of this study succeeded in showing the potential antifungal by endophytic fungi from ramie against the pathogens of the plant itself. P. citrinum isolate MEBP0017 showed the highest inhibition against all the pathogens of the ramie.

The Development of the Antibacterial Microcapsules of Citrus Essential Oil for the Cosmetotextile Application: A Review.

Essential oils (EOs) obtained from the Citrus genus were reported to exhibit good antimicrobial activity. Therefore, they can potentially be applied in daily necessities such as textile sectors as antibacterial functional fabric products. However, a packaging technique to retain such volatile and labile active substances is compulsory. In particular, microencapsulation was found to be a common coating technique employed to protect EOs from the effects of light, heat, humidity, stability, and controlled release of active substances. Various microencapsulation techniques have been introduced, but the most widely used method is complex coacervation, as it is simple, inexpensive, and capable of snaring high essential oils. Hence, this review focused on the microencapsulation of the most consumable citrus EOs with complex coacervation methods and their immobilization on commonly carried-out fabrics. In addition, it also discusses the isolation methods of the EOs, their chemical composition, and the mechanism of antibacterial action.

Microencapsulation of lime (Citrus aurantifolia) oil for antibacterial finishing of cotton fabric.

Functional cotton fabric incorporated with antibacterial microcapsules of lime (C. aurantifolia) essential oil (LO) was prepared. The coacervation method, employing two biopolymers of alginate and gelatin as the shells, was preferentially selected to produce the LO microcapsules, whereas immobilization of the LO microcapsules onto the fabric was done using the pad-dry-cure method using various concentrations of citric acid binder. The antibacterial inhibition zone of the functional fabric was subsequently analysed using the Kirby Bauer method. The LO microcapsules were produced with a yield, encapsulation efficiency (EE), and oil content (OC) of 47 ± 4%, 84 ± 11%, and 58 ± 4%, respectively. The homogenous spherical and soft microcapsules (1.554 µm) bonded effectively by 4% citric acid onto the surface of the fabric and detached back by only 3% after 15 cycles of washing. Overall, the optimized functional fabric exhibited the highest antibacterial activities among others against typical skin bacteria, such as S. aureus, E. coli, K. pneumoniae, and S. epidermidis, and thus it can be potentially applied to obtain antibacterial functional textile.