Natural Antimicrobials Research Articles

Antimicrobial and antioxidant study of combined essential oils of Anethum Sowa Kurz. and Trachyspermum ammi (L.) along with quality determination, comparative histo-anatomical features, GC‒MS and HPTLC chemometrics.

Spices played crucial and variable roles in traditions, culture, history, religious ceremonials and festivals along with fetching food flavor and microbial protection globally due to presence of structurally unique and multi-natured chemotypes. Their existence in dishes portrayed key roles in improving shelf life by regulating spoilage of cuisine with different synergistic mechanism. Histo-anatomically (A) sowa exhibited distinguished cellular attributes which created remarkable differences with T. ammi. HPTLC chemometrics of both fruits revealed several peaks for active metabolomics with unique isocratic combination of menstruum. GC-MS study of hydro-distillate exhibited presence of monoterpenic cyclic and aromatic hydrocarbons, alcoholic and ketonic groups along with phenolic derivative that covers majorly 90% of total metabolites. Combined essential oils (EOs 1 + 2) of both fruits showed excellent antimicrobial activity against various clinical pathogenic strains such as K. pneumoniae at 10 µL/mL, S. aureus at 2.5 µL/mL, E. coli and E. faecalis at 1.25 µL/mL, and MRSA and Bcereus at 0.625 µL/mL and (C) albicans at 0.312 µL/mL as the MIC. The antioxidant study of (EOs 1 + 2) with maximum inhibition percentage to DPPH assay was 84.02 ± 1.05 at 100µg/mL, and minimal inhibition was 72.31 ± 0.63 at 5µg/mL with IC50 value 4.69 ± 0.22µg/mL, while ABTS assay extreme was 79.15 ± 2.14µg/mL and minimal was 67 ± 1.34 with the IC50 value of 18.37 ± 0.15µg/mL, in superoxide assay uppermost inhibition was 81.03 ± 0.27µg/mL and lowest was at 65.16 ± 3.15 with the IC50 value 16.46 ± 0.54, and H2O2 radical scavenging activity, predominant value was 78.01 ± 0.47 and least was 64.1 ± 2.01 with IC50 15.58 ± 0.34. These comparative key diagnostic features and synergistic effect of multicomponent natural antimicrobials will provide profound intellect of ancient utility and further scientists to explore their multiple mechanistic modality and application in food and beverages industry.

Activity of Bambara Groundnut Seed Coat Extract Against Shewanella Species: Efficacy and Mechanisms of Action

The Bambara groundnut is the indigenous legume in the southern part of Thailand. It contains a seed coat rich in polyphenols, which can serve as natural antimicrobial agents. The extracts from red and white seed coats of Bambara groundnuts, namely RSC and WSC, respectively, were prepared using an ultrasound-assisted extraction process. The extraction yield, total phenolic content (TPC), and antimicrobial activity of both extracts were examined. The RSC extract demonstrated a significantly higher extraction yield (8.35%) than WSC extract (2.34%) (p < 0.05). Furthermore, the TPC of RSC extract (420.98 ± 0.27 mg of gallic acid/g dry extract) was higher than that of WSC extract (28.29 ± 0.91 mg of gallic acid/g dry extract). The RSC extract exhibited stronger inhibition against Shewanella putrefaciens and S. algae than its WSC counterpart. Liquid chromatography quadrupole time-of-flight mass spectrometry (LC-Q-TOF/MS) analysis indicated that the RSC extract was rich in flavonoids and polyphenols, while the WSC extract contained more triterpenoid saponins. Time–kill kinetics showed that the RSC extract reduced bacterial loads in a dose-dependent manner. Scanning electron microscopic images revealed that drastic bacterial cell membrane damage with a rough surface and the deformation of cells was caused by the extract. Furthermore, confocal laser scanning microscopic (CLSM) images confirmed the inhibition of S. algae biofilm formation by RSC extract. RSC extract also suppressed bacterial motility, induced protein leakage, and reduced extracellular protease activity, thus highlighting its potent bactericidal effects. These findings suggested that the RSC extract rich in phenolic compounds could serve as an antimicrobial agent and hold promise as a natural preservative for perishable foods, especially seafoods.

Natural Antimicrobial Agents from Algae: Current Advances and Future Directions

Infectious diseases have significantly shaped human history, leading to significant advancements in medical science. The discovery and development of antibiotics represented a critical breakthrough, but the rise of antibiotic-resistant pathogens now presents a serious global health threat. Due to the limitations of current synthetic antimicrobials, such as toxicity and environmental concerns, it is essential to explore alternative solutions. Algae, particularly microalgae and cyanobacteria, have emerged as promising sources of bioactive antimicrobial compounds. This review provides a comprehensive analysis of the antimicrobial properties of algal-derived compounds, including polysaccharides, fatty acids, and phenols, which have shown effectiveness against multi-drug-resistant bacteria. A co-occurrence bibliometric analysis using VOSviewer highlighted five key research clusters: antibiotic resistance, algal extracts, biosynthesis, water treatment, and novel pharmacological compounds. Furthermore, the primary mechanisms of action of these bioactive compounds, such as the inhibition of protein synthesis and cell membrane disruption, were identified, demonstrating their potential against both common and multi-resistant pathogens. Future research should prioritize optimizing algal biomass production, utilizing genetic and metabolic engineering, and creating innovative delivery systems to enhance the efficient production of bioactive compounds.

VARIOUS SOLVENT EXTRACTS OF Ipomoea pes-caprae: A PROMISING SOURCE OF NATURAL BIOACTIVE COMPOUNDS COMPARE WITH VITAMIN C

This research investigates the phytochemical composition, antioxidant activity, and antibacterial efficacy of Ipomoea pes-caprae extracts collected from Pantai Talang Siring Pamekasan, Madura. Phytochemical analysis revealed the presence of alkaloids, flavonoids, phenolic compounds, terpenoids, tannins, and saponins in the extracts, indicating their rich bioactive profile. Antioxidant activity assessed via the DPPH assay demonstrated concentration-dependent scavenging of free radicals, with methanol and ethanol extracts exhibiting superior activity compared to the aqueous extract. Antibacterial assays against Escherichia coli and Staphylococcus aureus revealed significant inhibitory effects, with methanol and ethanol extracts displaying greater potency than the aqueous extract. These findings underscore the potential of Ipomoea pes-caprae as a source of natural antioxidants and antimicrobial agents, warranting further investigation into its pharmacological applications and therapeutic potential.

A brief review on Antibacterial activity of Citrullus Colocynthis

Due to contamination or the rapid microbial growth that happens naturally in fish, seafood is very poorly preserved. Fish storage facilities commonly employ artificial preservatives to guarantee quality and safety while prolonging shelf life. Natural preservatives originating from plants, animals, and microbes have been shown to have the ability to take the place of synthetic antimicrobials. The bitter fruit Citrullus colocynthis has been used as a natural preservative. It belongs to the family Cucurbitaceae. The wild melon species also known as colocynth produces cantaloupe-sized fruits with a bitter flavor and seeds that are high in protein and oil. It is a prolonged perennial that thrives in xerophilic environments on sandy shores. When young, fruits are plump and speckled with dark green; when ripe, they typically become yellow. Since ancient times, the fruit of colocynthis has been used medicinally. The current study intends to investigate antibacterial properties of C. colocynthis on gram-negative bacteria E.coli & gram positive bacteria S.aureus. Natural antimicrobials derived from plants, animals, and microbes have the potential to replace chemical antimicrobials. Utilizing UV spectrometery, the chemical characterization of extracts was accomplished. Nile tilapia fish species was used for this experiment to determine antibacterial potential of C. colocynthis.

Antimicrobial Activity of Commercial Essential Oils Available in the Market of Kathmandu

Given the increasing global apprehension surrounding antibiotic resistance, there has been growing interest in exploring natural compounds, specifically essential oils, as potential substitutes for combating microbial pathogens. This research work aimed to evaluate the antimicrobial activity exhibited by commercial essential oils and by diluting them with the carrier oils at equal concentration. The screening of antimicrobial activity was conducted using the agar well diffusion method with eight essential oils. Using the broth dilution method, the antibacterial activity of eight commonly used essential oils: lavender, tea tree, eucalyptus, peppermint, thyme, citrus, rosemary, and cinnamon were assessed. Both Gram-positive and Gram-negative species were selected for antimicrobial activity. The minimum inhibitory concentration (MIC) was determined by the broth dilution method. Following MIC determination, a sub-culture was performed on nutrient agar plates to ascertain the minimum bactericidal concentration (MBC). All the antibiotics used in the study demonstrated sensitivity when subjected to the antibiotic susceptibility test. Thyme, cinnamon and peppermint strongly inhibited the growth of S. epidermidis 46 mm, 30mm, and 34 mm respectively. Findings revealed distinct variations in the MIC values among the different essential oils and bacteria tested. Thyme and tea tree oils exhibited the broadest antibacterial spectrum, inhibiting both Gram-positive and Gram-negative bacteria at relatively low concentrations. Thyme (15.625 μl/ml) and tea tree (31.25 μl/ml) oil demonstrated promising activity against Gram-positive pathogen, while tea tree oil (15.625 μl/ml) displayed better efficacy against Gram-negative bacteria. A significant outcome was observed when the essential oils were diluted with carrier oils, indicating promising results in terms of antibacterial activity. These findings highlight the potential of essential oils, particularly thyme and tea tree oils, as effective natural antimicrobial agents.

Advancing antimicrobial efficacy of Cucumis momordica seeds: Nanoemulsion application in Eurotium cristatum-mediated solid-state fermentation

This study explores the enhancement of Cucumis momordica seed powder's properties through Eurotium cristatum-mediated solid-state fermentation (SSF) and its application in nanoemulsions, emphasizing protein content, functional properties, stability, and antimicrobial activity. The protein content increased significantly from 23.28±0.23 % in the control to 29.83±0.12 % after 144 h of fermentation. The Cucumis momordica seed powder fermented for 96 h was further analyzed for its functional properties and characterization. The water absorption capacity was increased from 0.91 to 2.56 g/g, and oil absorption capacity from 0.79 to 1.16 g/g. SEM and FTIR analyses revealed morphological changes and chemical profile alterations, indicating enzymatic degradation and enhanced functional properties. Nanoemulsions from fermented powder showed reduced droplet sizes (148±0.34 nm to 126±0.37 nm) and more negative zeta potentials (-24.5±0.12 mV to −25.79±0.18 mV), suggesting improved stability. Temperature stability was superior in fermented seed powder nanoemulsions, demonstrating enhanced thermal resistance. Antimicrobial tests against E. coli and S. aureus showed significantly lower MIC and MBC values for fermented powder nanoemulsions (E. coli MIC: 1.089 mg/mL, MBC: 2.189 mg/mL; S. aureus MIC: 0.459 mg/mL, MBC: 1.196 mg/mL), indicating increased antimicrobial efficacy. These results highlight the potential of SSF and nanoemulsion technology in advancing the functionality and application of Cucumis Momordica seeds as natural antimicrobial agents.

Sumac extract as a natural preservative in mayonnaise: Effects on lipid oxidation, microbial growth, physicochemical, rheological, and sensory characteristics

The present study was conducted to evaluate the effect of sumac extract (SE) as a natural antioxidant and antimicrobial agent on the quality characteristics of low-fat mayonnaise during 63 days of storage. The SE was used at levels of 1 % (SE1%), 3 % (SE3%), and 5 % (SE5%) in the formulations. The two control treatments were produced with chemical preservatives (C1) and without preservatives (C2). The SE caused a significant decrease in peroxide and anisidine values compared to controls after 63 days (4.73–5.77 meq/kg vs. 6.33–6.73 meq/kg for peroxide values, and 6.29–11.21 vs. 12–13.60 for anisidine values, P < 0.05). The higher inhibitory effects of SE on microbial growth in mayonnaises were revealed after 63 days, where the total viable count declined from the highest value (36.5 log CFU/g) in C2 to the lowest count (12 log CFU/g) in SE5%. The yeasts and molds count in SE1% (4.5 log CFU/g) were lower than the counts of 20.5 log CFU/g and 23.5 log CFU/g observed in C1 and C2, respectively. Moreover, significant reductions in Lactic Acid Bacteria were observed in SE-enriched treatments (P < 0.05). The phenolic and flavonoid contents of mayonnaise treatments besides antioxidant capacity were enhanced by increasing SE concentrations. However, the lowest storage modulus and complex viscosity were observed in SE5%. The highest overall acceptance belonged to C1 followed by SE1% at the end of storage. Finally, SE has the potential to be used as a natural preservative in mayonnaise.

Plant-Based Ingredients Utilized as Fat Replacers and Natural Antimicrobial Agents in Beef Burgers.

The present study aimed to find solutions based on the use of plant-based ingredients that would improve the nutritional quality of meat products as well as ensure sensory and microbiological quality. Two fat replacers, lemon albedo (Citrus lemon) and carob seed gum (Ceratonia siliqua), were investigated by chemical analysis and panel testing to evaluate their effect on the nutritional and sensory quality of beef burgers. The antimicrobial activity of two plant extracts, from nettle (Urtica dioica) leaves and medlar (Eriobotrya japonica) seeds, was studied, evaluating the intensity of inhibitory action and the minimum inhibitory concentration against Pseudomonas spp. and Listeria innocua strains by plate test. In addition, the antioxidant activity of both extracts was evaluated. Based on the results, lemon albedo and medlar seed extracts were validated in a food model (beef burger) by a storage test and a challenge test. The storage test results highlight that medlar seed extract prevents the formation of thiobarbituric acid reactive substances (TBARSs) and ensures microbiological quality, inhibiting Enterobacteriaceae and Pseudomonas spp. Anti-Listeria efficacy was confirmed in situ by challenge test results. In conclusion, although fat replacers ensure nutritional and sensory quality, they do not satisfy microbiological quality. This study clearly demonstrates that the safety of low-fat burgers can only be achieved through the combination of appropriate fat replacers with well-selected natural antimicrobial extracts.

The Antimicrobial Efficacy and Quality Changes in Pineapple Juice Treated with Natural Preservatives

The study investigated effects of natural preservatives on the quality of fresh pineapple fruit juice. The natural preservatives used are ginger, garlic, moringa seed and cloves and were processed into powder. The treatment of pineapple with the natural preservatives was at a concentration of 20% with 3 minutes dipping time. The enumeration and identification of microorganisms on the fresh pineapple fruit, shows that the total bacteria count was 1.8×105 colony forming unit per gram (CFU/g) and 4.6×103 CFU/g respectively. The identified bacteria are staphylococcus aureus and streptococcus spp and identified fungi were Aspergillus Niger, penicillin spp and Aspergillus perfrigens respectively. Moringa seed extract exhibited moderate antibacterial activity, with zones of inhibitions (ZOIs) of 16 mm against Staphylococcus aureus and 15 mm against Streptococcus spp. Garlic (GL) showed the least antibacterial activity among the natural preservative samples, with 9mm zones of inhibition against Staphylococcus aureus and 4 mm against Streptococcus spp. Clove extract displayed significant antibacterial activity, with 14 mm zones of inhibition against Staphylococcus aureus and 19 mm against Streptococcus spp. Ginger extract exhibited slight antibacterial activity, with zones of inhibition of 4 mm against both bacterial strains. Chemical composition of the treated pineapple juice result ranges from 0.77-0.865% TTA, 64.12-63.10 Vit C, 26.50-25.06 Brix Content,3.20-3.39 pH and 13.23-13.17 TSS respectively. The control (100% pineapple Juice) displayed balanced properties serving as an effective baseline3. Storage studies, ambient stored samples were analyzed at 0 day and 21 days intervals. All samples were subjected to standard analytical methods. Results showed increase in number of bacteria and fungi with increase in the number of days. The use of cloves, garlic, ginger, and moringa seeds as natural antimicrobial agents in pineapple juice is effective in controlling microbial growth, thus enhancing the safety and shelf life of the juice. These treatments also influence the chemical and sensory properties of the juice, contributing to consumer acceptability.

Exploring Myrrh Oil as a Natural Antimicrobial Agent Against Oral Pathogens: An In Vitro Research

Background: While contemporary pharmaceuticals play a critical role in managing oral infections, there remain persistent concerns regarding their chemical composition and potential adverse effects. This apprehension has led to an increased focus on exploring natural alternatives, particularly herbal substances, for their potential therapeutic benefits in oral health. Aim: This study aimed to examine the antibacterial properties of myrrh oil against common oral bacteria, including Candida, Escherichia coli, Klebsiella, and Staphylococcus aureus, and to assess its suitability as a natural alternative in oral healthcare. Methods: Oral swabs were obtained from 50 individuals from various socioeconomic backgrounds. The isolated organisms were cultivated on different types of media and identified using established microbiological methods. Bacterial growth inhibition was evaluated by culturing subsequent cultures on Muller-Hinton agar with myrrh oil. This agar medium was selected for its suitability in evaluating myrrh oil’s suppressive impact on oral bacteria proliferation. Results: Candida demonstrated abundant proliferation on the control media but showed a reduction in colony-forming units when treated with myrrh oil. E. coli, Klebsiella, and Staphylococcus aureus exhibited decreased growth and suppressed colony formation when exposed to myrrh oil. Conclusion: These findings indicate that myrrh oil can prevent the growth of oral bacteria, making it a promising natural antibacterial agent for managing oral health. Additional investigations are needed to examine the safety, ideal dosage, and clinical feasibility of this treatment.

Campylobacter control strategies at postharvest level.

Campylobacter is highly associated with poultry and frequently causes foodborne illness worldwide. Thus, effective control measures are necessary to reduce or prevent human infections. In this review, Campylobacter control methods applicable at postharvest level for poultry meat during production, storage, and preparation are discussed. Drying and temperature are discussed as general strategies. Traditional strategies such as steaming, freezing, sanitizing, organic acid treatment, and ultraviolet light treatment are also discussed. Recent advances in nanotechnology using antibacterial nanoparticles and natural antimicrobial agents from plants and food byproducts are also discussed. Although advances have been made and there are various methods for preventing Campylobacter contamination, it is still challenging to prevent Campylobacter contamination in raw poultry meats with current methods. In addition, some studies have shown that large strain-to-strain variation in susceptibility to these methods exists. Therefore, more effective methods or approaches need to be developed to substantially reduce human infections caused by Campylobacter.

Unveiling the Chemical Constituents and Inhibitory Roles of Extracts from Pinus Pinea L. Nut and Nutshell: A Novel Source for Pharmaceutical Antimicrobials.

Antibiotic resistance in infectious diseases has been a serious problem for the last century, and scientists have focused on discovering new natural antimicrobial agents. Pinus pinea has been used as a natural pharmacotherapeutic agent with antimutagenic, anticarcinogenic, and high antioxidant properties. In this study, GC-MS and LC-HR/MS were employed to analyze Pinus pinea L. nut and nutshell extracts. DPPH radical scavenging assay was performed to analyze the antioxidant properties of the extracts, but no activity was determined. GC-MS analysis showed that linoleic, oleic, and palmitic acids were the three most dominant fatty acids in nut and nutshell extracts, with ratios between 6.75 % and 47.06 % (v/v). LC-HR/MS revealed that the nutshell methanol extract had a higher phenolic content than other extracts, with vanillic acid (1.4071 mg/g). Antimicrobial activity assays showed that the minimum inhibitory concentrations (MIC) of the extracts varied between 5.94 and 190 mg/mL, and the most significant inhibition was seen in the nutshell methanol extract (MICs: between 5.94 and 47.5 mg/mL). Consequently, the antimicrobial activity of the extracts can be attributed to the dense fatty acids they contain, and the nutshell methanol extract showed the most potent inhibition related to the abundance of phenolic compounds in the extract.

Efficient enhancement of the antimicrobial activity of Chlamydomonas reinhardtii extract by transgene expression and molecular modification using ionizing radiation

BackgroundIonizing radiation has been used for mutagenesis or material modification. The potential to use microalgae as a platform for antimicrobial production has been reported, but little work has been done to advance it beyond characterization to biotechnology. This study explored two different applications of ionizing radiation as a metabolic remodeler and a molecular modifier to enhance the antimicrobial activity of total protein and solvent extracts of Chlamydomonas reinhardtii cells.ResultsFirst, highly efficient transgenic C. reinhardtii strains expressing the plant-derived antimicrobial peptides, AtPR1 or AtTHI2.1, were developed using the radiation-inducible promoter, CrRPA70Ap. Low transgene expression was significantly improved through X-irradiation (12–50 Gy), with peak activity observed within 2 h. Protein extracts from these strains after X-irradiation showed enhanced antimicrobial activity against the prokaryotic bacterium, Pseudomonas syringae, and the eukaryotic fungus, Cryptococcus neoformans. In addition, X-irradiation (12 Gy) increased the growth and biomass of the transgenic strains. Second, C. reinhardtii cell extracts in ethanol were γ-irradiated (5–20 kGy), leading to molecular modifications and increased antimicrobial activity against the phytopathogenic bacteria, P. syringae and Burkholderia glumae, in a dose-dependent manner. These changes were associated with alterations in fatty acid composition. When both transgenic expression of antimicrobial peptides and molecular modification of bioactive substances were applied, the antimicrobial activity of C. reinhardtii cell extracts was further enhanced to some extent.ConclusionOverall, these findings suggest that ionizing radiation can significantly enhance the antimicrobial potential of C. reinhardtii through efficient transgene expression and molecular modification of bioactive substances, making it a valuable source of natural antimicrobial agents. Ionizing radiation can act not only as a metabolic remodeler of transgene expression in microalgae but also as a molecular modifier of the bioactive substances.

Antibacterial Power of Lemon Essential Oil, Ginger And Their Synergy With Neem Vegetable Oil On Mastitis Pathogenic Germs Dairy Cows From The Poro Region In Ivory Coast

Gas chromatography-mass spectrometry analysis of essential oils of (Citrus limon, Zingiber officinalis and Azadirachta indica vegetable oil), purchased, identified 32.80%, 42.40% and 47.10% of its constituents. This study consisted of evaluating the antimicrobial performance of some EOs obtained from three medicinal plants, considered to have a great bacterial effect. This is in order to standardize their use to apply them as an alternative remedy to antibiotics in the face of the advance of resistant bacteria and the failure of antibiotic therapy. The essential oils of these plants were tested alone or in combination on nine pathogenic microbial strains from cows suffering from mastitis and resistant to certain antibiotics, namely: four Gram (-) bacterial strains (Pseudomonas aeruginosa, E. coli ATCC25922, E. coli, Klebsiella spp) ; five Gram (+) bacterial strains (Staphylococcus aureus, Micrococcus spp, S. aureus ATCC19213, SCN (S. lentus and S. xylosus)); and E. coli ATCC25922, S. aureus ATCC19213 as reference strains. Reasonable antimicrobial activities of the studied EOs were observed on some of the germs tested. All the strains tested are sensitive to concentrations less than or equal to 100μg.ml -1 of essential oil. Enterobacteria (Escherichia coli, Klebsiella spp) are resistant to standard antibiotics with the exception of Colistin, which have been shown to be sensitive to all essential oils studied. This observation applies to Gram-positive cocci (Staphylococcus aureus, Micrococcus spp, Staphylococcus lentus and Staphylococcus sylosus) which are very sensitive to the oils studied but resistant to three types of standard antibiotics (Ampicillin, Colistin and Penicillin). The CMB/MIC ratios of Zingiber officinalis and Citrus limon oils have a bacteriostatic action while that of the combination of EO (Zingiber officinalis, Citrus limon and Azadirachta indica oil ) are bactericidal on all bacterial strains tested. There was no significant difference between the MIC and MBC values of the essential oil resistant strains. As a result of the study, an idea could be proposed for the development and upgrading of a new generation of combination of natural antimicrobial agents that can be used in humans and animals against infections with commonly used antibiotics.

Maximizing polyphenol yield: ultrasound-assisted extraction and antimicrobial potential of mango peel

This study investigated the ultrasound-assisted extraction (UAE) techniques used to enhance the polyphenols and antioxidants of mango peel extract (MPE). Additionally, it explored the bacteriostatic activity of MPE against various microorganisms. The UAE method was optimized using response surface methodology (RSM) at different times, temperatures, and ratios, with optimal conditions found to be 35 minutes, 45 °C, and a 1:35 ratio. The optimized yield results for total polyphenol content (TPC) were 17.33 ± 1.57 mg GAE/g, total flavonoid content (TFC) was 12.14 ± 0.29 mg QE/g, and radical scavenging activity (RSA) was 72.11 ± 2.19%. These response models were extremely significant with p-values less than 0.05. MPE showed selective effectiveness against Bacillus cereus, Geobacillus stearothermophilus, and Escherichia coli (E. coli). The results highlight the potential of mango peel as a sustainable source of bioactive compounds, contributing to waste reduction in the food industry and the development of natural antimicrobial agents. This study contributes to further research on the application of MPE in processed foods.

Unlocking the Potential of Hydrosols: Transforming Essential Oil Byproducts into Valuable Resources

The global demand for sustainable and non-toxic alternatives across various industries is driving the exploration of naturally derived solutions. Hydrosols, also known as hydrolates, represent a promising yet underutilised byproduct of the extraction process of essential oils (EOs). These aqueous solutions contain a complex mixture of EO traces and water-soluble compounds and exhibit significant biological activity. To fully use these new solutions, it is necessary to understand how factors, such as distillation time and plant-to-water ratio, affect their chemical composition and biological activity. Such insights are crucial for the standardisation and quality control of hydrosols. Hydrosols have demonstrated noteworthy properties as natural antimicrobials, capable of preventing biofilm formation, and as antioxidants, mitigating oxidative stress. These characteristics position hydrosols as versatile ingredients for various applications, including biopesticides, preservatives, food additives, anti-browning agents, pharmaceutical antibiotics, cosmetic bioactives, and even anti-tumour agents in medical treatments. Understanding the underlying mechanisms of these activities is also essential for advancing their use. In this context, this review compiles and analyses the current literature on hydrosols’ chemical and biological properties, highlighting their potential applications and envisioning future research directions. These developments are consistent with a circular bio-based economy, where an industrial byproduct derived from biological sources is repurposed for new applications.

Cryptophytes as potential source of natural antimicrobials for food preservation.

Cryptophytes are a promising source of bioactive compounds that have not been fully explored. This research investigated the antimicrobial activity of total phenolic compounds (TPC) and exopolysaccharides (EPS) extracted from several cryptophytes against a range of harmful foodborne bacteria and fungi. To measure the minimum inhibitory concentration (MIC) value, the broth microdilution method was used. In the antibacterial evaluation of TPC, the MIC ranged between 31.25 and 500 μg/mL, while for the antifungal activity test, it varied from 31.25 to 125 μg/mL. In the antibacterial activity test of EPS, the MIC values ranged from 125 to 1,000 μg/mL, whereas in the antifungal susceptibility test, it ranged between 62.5 and 1,000 μg/mL. The most resistant pathogen against TPC was Escherichia coli, while Campylobacter jejuni was the most susceptible. In the case of EPS, the most resistant pathogen was Salmonella Typhimurium, while Aspergillus versicolor exhibited the highest susceptibility. Overall, in terms of antimicrobial activity, TPC was more effective than EPS. Finally, the tolerance level (TL) for TPC and EPS was ≤4 in all tested samples, indicating their bactericidal/fungicidal mechanism of action. In conclusion, TPC and EPS isolated from cryptophytes demonstrated remarkable antimicrobial properties and ability to fully eradicate pathogens, and could be considered as natural preservatives in the food industry.

Synthetic vs. natural antimicrobial agents for safer textiles: a comparative review.

Textiles in all forms act as carriers in transmitting pathogens and provide a medium of microbial growth, especially in those fabrics which are used in sports, medical and innerwear clothing. More attention towards hygiene and personal healthcare made it a necessity to develop pathogen-free textiles. Synthetic and natural antimicrobial compositions are used to control and reduce microbial activity by killing or inhibiting microbial growth on textiles. Synthetic metallic nanoparticles of Ag, Zn, Cu Ti and Ga are the most commonly and recently used advanced nanocomposites. Synthetic organic materials such as triclosan, quaternary ammonium compounds, polyhexamethylene biguanide, and N-halamines have proven antimicrobial activity. Carbon quantum dots are one of the advanced nanomaterials prepared from different kinds of organic carbon material with photoluminescence efficiency also work efficiently in antimicrobial textiles. A greener approach for producing natural antimicrobial textiles has gained significant importance and demand for personal care due to their less toxic effects on health and the environment In comparison to synthetic. The naturally existing materials including extracts and essential oils of plants have significant applications for antimicrobial textiles. Additionally, a number of animal extracts are also used as antimicrobial agents include chitosan, alginate, collagen hydrolysate to prepare naturally treated antimicrobial textiles. This review focuses on the comparative performance of antimicrobial fabrics between synthetic and natural materials. Textiles with synthetic substances cause health and environmental concerns whereas textiles treated with natural compositions are more safe and eco-friendly. Finally, it is concluded that textiles modified with natural antimicrobial compositions may be a better alternative and option as functional textiles.

Formulating Sustainable Emulsions: Mandelic Acid and Essential Oils as Natural Preservatives.

Emulsion products with natural antimicrobials are becoming increasingly popular for topical application. Mandelic Acid is interesting in cosmetics due to its potent exfoliating properties, which have driven advancements in skincare technologies. Essential oils have various properties, of which the most useful in cosmetics are those that do not cause irritation, smell pleasant, and have other beneficial properties such as antimicrobial effects. Emulsions with Mandelic Acid and essential oils from Satureja montana, Lemongrass, and Litsea cubeba were formulated and microbiologically tested for their preservative effectiveness. The effect of the treatments on skin condition was monitored by non-invasive diagnostic methods, such as hydration, transepidermal water loss, and pH value. Sensory analysis revealed that the matrix containing Mandelic Acid alone or combined with Litsea Cubeba Oil was the best-performing formulation, consistent with the compliant results of antimicrobial efficacy. The topical form of this cosmetic product has demonstrated excellent preservative activity and desirable biophysical efficacy on the skin.