Evaluation and utilization of lemongrass oil nanoemulsion for disinfection of documentary heritage based on parchment

Antifungal Activity of Cell-Free Filtrate of Probiotic Bacteria Lactobacillus rhamnosus ATCC-7469 against Fungal Strains Isolated from a Historical Manuscript

Herein, twelve fungal strains were isolated from a deteriorated historical manuscript dated back to the 18th century. The obtained fungal strains were identified, using the traditional method and ITS sequence analysis, as Cladosporium herbarum (two strains), Aspergillus fumigatus (five strains), A. ustus (one strain), A. flavus (two strains), A. niger (one strain), and Penicillium chrysogenum (one strain). The ability of these fungal strains to degrade the main components of the paper was investigated by their activity to secrete extracellular enzymes including cellulase, amylase, gelatinase, and pectinase. The cell-free filtrate (CFF) ability of the probiotic bacterial strain Lactobacillus rhamnosus ATCC-7469 to inhibit fungal growth was investigated. The metabolic profile of CFF was detected by GC-MS analysis, which confirmed the low and high molecular weight of various active chemical compounds. The safe dose to be used for the biocontrol of fungal growth was selected by investigating the biocompatibility of CFF and two normal cell lines, Wi38 (normal lung tissue) and HFB4 (normal human skin melanocyte). Data showed that the CFF has a cytotoxic effect against the two normal cell lines at high concentrations, with IC₅₀ values of 525.2 ± 9.8 and 329.1 ± 4.2 µg mL^-1 for Wi38 and HFB4, respectively. The antifungal activity showed that the CFF has promising activity against all fungal strains in a concentration-dependent manner. The highest antifungal activity (100%) was recorded for a concentration of 300 µg mL^-1 with a zone of inhibition (ZOI) in the ranges of 21.3 ± 0.6 to 17.7 ± 0.5 mm. At a concentration of 100 µg mL^-1, the activity of CFF remained effective against all fungal strains (100%), but its effectiveness decreased to only inhibit the growth of eight strains (66%) out of the total at 50 µg mL^-1. In general, probiotic bacterial strains containing CFF are safe and can be considered as a potential option for inhibiting the growth of various fungal strains. It is recommended that they be used in the preservation of degraded historical papers.

New frontiers review of some recent conservation techniques of organic and inorganic archaeological artefacts against microbial deterioration

The information on the advances and technology of some recent conservation methods (2020–2023) of organic and inorganic archaeological objects against microbial deterioration is recorded. An outline of comparative new protective methods for conserving plant-origin organic artefacts {Fibers (manuscripts, textile) and wood}, animal-origin organic artefacts (painting, parchment and mummies) and inorganic stone artefacts were investigated. The work not only contributes to the development of safe revolutionary ways for more efficient safe conservation of items of historical and cultural worth but also serves as a significant diagnostic signature for detecting the sorts of microbial identification and incidents in antiques. Biological technologies (environmentally friendly green biocides) are the most used recent, efficient and safe strategy acceptable as alternatives to stop microbial deterioration and prevent any potential interactions between the biological agent and the artefacts. Also, a synergistic effect of combining natural biocides with mechanical cleaning or chemical treatments was suggested. The recommended exploration techniques should be considered for future applications.

Antimicrobial, Pesticidal and Food Preservative Applications of Lemongrass Oil Nanoemulsion: A Mini-Review

BACKGROUND

Essential oils that are extracted from plants have shown beneficial effects on humans and animals, evidenced by traditional medicine. They possess many essential phytocomponents that act as antimicrobial agents, and most of them are safe for external usage.

INTRODUCTION

Lemongrass essential oil is extracted from the grass, such as Cymbopogon flexuosus, and is used for antimicrobial activity for a long time. The efficacy of this oil is limited due to the poor solubility and microbial penetration, easy vaporization, and lower stability. Nanoformulations and nanoencapsulations are nanotechnology fields that aim to improve the bioavailability of many natural compounds and enhance their stability. Lemongrass oil has also been nanoformulated as nanoemulsion, and various antimicrobial activities against various pathogens have been demonstrated, which are superior to free lemongrass oil.

METHODOLOGY

We have used the search engines PubMed and Google Scholar for the mentioned keywords and selected the recent references related to this topic.

CONCLUSION

In this review, we have discussed various antimicrobial properties of lemongrass essential oil nanoemulsion and its application, such as antibacterial, antifungal, pesticidal, food preservative, and antibiofilm activity.

Fungal Biodeterioration of a Historical Manuscript Dating Back to the 14th Century: An Insight into Various Fungal Strains and Their Enzymatic Activities

This study aims to assess the deterioration aspects of a historical manuscript dating back to the 14th century that was deposited in the Library of the Arabic Language Academy, Cairo, Egypt. The study aims at the exploration of the role of various fungal strains that had colonized this deteriorated manuscript in its biodeterioration through their efficacy in the secretion of various hydrolytic enzymes. To evaluate the deterioration, various techniques, including visual inspection, attenuated total reflectance Fourier transform infrared (ATR-FTIR), scanning electron microscopy (SEM), X-Ray diffraction analysis (XRD), color change, and pH value, were utilized. The fungal strains linked to the historical document were isolated, identified, and evaluated for their deterioration activities. The findings demonstrate that the manuscript exhibits a variety of deterioration signs including color change, brittleness and weakness, erosion, and removal of the grain surface pattern in leather binding. According to the ATR-FTIR, the chemical composition of the historical paper and leather underwent some alterations. The historical paper has a lower level of cellulose crystallinity than the control sample. Penicillium chrysogenum (two isolates), P. citrinum (four isolates), Aspergillus ustus (three isolates), A. terreus (two isolates), A. chinensis (one isolate), Paecilomyces sp. (one isolate), and Induratia sp. (one isolate) were among the fourteen fungal strains identified as being associated with the historical manuscript. These fungal strains produced several hydrolytic enzymes with high activity, such as cellulase, amylase, gelatinase, and pectinase, which play a key role in biodegradation.

Exploring phytochemical composition, photocatalytic, antibacterial, and antifungal efficacies of Au NPs supported by Cymbopogon flexuosus essential oil

Biofabrication of gold nanoparticles (AuNPs) using the aromatic essential oils is highlighted due to its simple, economical, low toxicity, and eco-friendly nature. Essential oil of Cymbopogon flexuosus (CF), an economically valuable medicinal plant, exhibits anti-inflammatory, anti-tumor, antioxidant, and antimicrobial activities. For the first time, this research accounts for the biosynthesis, physicochemical, photocatalytic, antifungal, antibacterial properties of biogenic AuNPs, fabricated using CF essential oil collected from different altitudes (S1-Palampur, S2-Haryana, S3-Dehradun). The altitudinal disparity in the phytochemical composition of essential oils is highlighted. The average crystallite size ranged from 10 to 32 nm and was influenced by CF samples used in the synthesis. The spectroscopic outcomes revealed the involvement of bioactive reagents from CF essential oil in the fabrication and stabilization of AuNPs. The fabricated AuNPs exhibited excellent antimicrobial activities against all tested strains (Staphyloccucs aureus, Escherichia coli, Fusarium oxysporum), showing their efficacy as an antimicrobial agent to treat infectious diseases. Moreover, AuNPs exhibited excellent photocatalytic efficacy of around 91.8% for the degradation of methylene blue under exposure of direct sunlight for 3 h without the assistance of an external reducing agent. The outcomes highlight a potential economic and environmentally friendly strategy to fabricate biogenic AuNPs for diversified industrial applications where antimicrobial and photocatalytic efficacies are the key requirements.

Three-Dimensional Nanoscale Morphological Surface Analysis of Polymeric Particles Containing Allium sativum Essential Oil

Biodegradable particles were developed using poly-ε-caprolactone and gelatin carriers containing different concentrations of Allium sativum essential oil (EO) (360 µg/mL, 420 µg/mL, and 460 µg/mL). Atomic force microscopy was useful to evaluate the particles' surface based on morphological parameters. The particles' size varied from 150 nm to 300 nm. The diameter was related to the increase of the particles' height as a function of the EO concentration, influencing the roughness of the surface core values (from 20 to 30 nm) and surface irregularity. The spatial parameters Str (texture aspect ratio) and Std (texture direction) revealed low spatial frequency components. The hybrid parameters Sdq (root mean square gradient) and Sdr (interfacial area ratio) also increased as a function of the EO concentration, revealing fewer flat particles. On the other hand, the functional parameters (inverse areal material ratio and peak extreme height) suggested differences in surface irregularities. Higher concentrations of EO resulted in greater microtexture asperity on the particles' surface, as well as sharper peaks. The nanoscale morphological surface analysis allowed the determination of the most appropriate concentration of encapsulated EO, influencing statistical surface parameters.