Bacillus Subtilis ATCC Research Articles

Identification and Assessment of Secondary Metabolites from Three Fungal Endophytes of Solanum mauritianum Against Public Health Pathogens

Fungal endophytes, symbiotic microorganisms residing within plants, are renowned for producing bioactive secondary metabolites with diverse beneficial properties. We investigated the antimicrobial potential of fungal endophytes isolated from Solanum mauritianum, an invasive weed, against clinically significant bacterial pathogens. Selected fungal endophytes (Penicillium chrysogenum, Fusarium sp., and Paracamarosporium leucadendri) were isolated from the plant’s leaves and fruits. Their crude extracts were tested against various referenced strains, such as Mycobacterium species (M. smegmatis ATCC 607 and M. bovis ATCC 27290), Staphylococcus aureus ATCC 6571, Bacillus subtilis ATCC 11774, Klebsiella species (K. pneumoniae ATCC 10031 and K. oxytoca ATCC 8724), Escherichia coli ATCC 10536, and Pseudomonas aeruginosa ATCC 10145, using the Kirby-Bauer disk diffusion method. Resazurin Microtiter Assay was used for the determination of the minimum inhibitory concentration. The chemical nature of the secondary metabolites in the crude extracts produced by fungal endophytes was evaluated using high-resolution liquid chromatography–mass spectrometry (LC-MS) using water and acetonitrile gradient. Liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF-MS/MS) was employed for untargeted metabolomics. LC-QTOF-MS/MS identified 63 bioactive compounds across the three endophytes. P. chrysogenum had the highest activity against S. aureus and M. smegmatis (1.15 mg/mL and 0.02 mg/mL, respectively), while P. leucadendri demonstrated moderate activity against M. smegmatis (2.91 mg/mL) and E. coli (1.16 mg/mL). Fusarium sp. exhibited the broadest spectrum of antibacterial activity, with MIC values ranging from 0.03 mg/mL (B. subtilis) to 10 mg/mL (M. smegmatis). P. leucadendri produced 29 metabolites, Fusarium sp. had 23 identified metabolites, and a total of 11 metabolites were identified from P. chrysogenum. The fruits of the plant, accounting for 60%, appeared to be the most abundant in the endophyte diversity when compared to the stems and leaves. This study highlights the potential of fungal endophytes from S. mauritianum as a source of novel bioactive compounds, particularly against multidrug-resistant pathogens, contributing to the ongoing efforts to combat antimicrobial resistance.

Synthesis and Characterization of 4-Hydroxy-3-((2-Hydroxy-3-Methoxybenzylidene)Amino)Benzenesulfonic Acid and Its Metal Complexes and their Antimicrobial Activity

Schiff base was obtained from the reaction of vanillin with 3-amino-4-hydroxybenzenesulfonic acid. Metal complexes were synthesized using (Ni(NO3)2, Co(NO3)2, Mn(NO3)2, Cu(NO3)2, Zn(NO3)2) metal salts and the structures of the compounds were elucidated by spectroscopic methods. The structures of the metal complexes were also characterized by elemental analysis, FT-IR, thermogravimetric analysis and magnetic susceptibility analysis and their antimicrobial activities were investigated. The antimicrobial activities of the obtained coordination compounds were investigated against three Gram-positive (Bacillus subtilis ATCC 6633; Staphylococcus aureus ATCC 25923; Enterococcus faecalis ATCC 29212) three Gram-negative bacterial (Escherichia coli ATCC 25922; Klebsiella pneumonia ATCC 70060; Pseudomonas aeruginosa ATCC 27853) strains and two fungal (Aspergillus niger ATCC 16404; Candida albicans ATCC 1023) strains, and the minimum inhibitory concentration (MIC) values were determined. According to the MIC values, the SC-Ni complex exhibited the highest antimicrobial activity, while the SC-Cu complex showed the lowest.

Abietane diterpenoid salvipisone: Structure elucidation, conformational analysis, and antimicrobial activity

Salvipisone, an abietane diterpenoid, was isolated from the roots of Salvia aethiopis L. using a combination of chromatographic separation techniques. Its structure was elucidated employing a variety of spectroscopic methods, including ultraviolet (UV), infrared (IR), 1D and 2D nuclear magnetic resonance (NMR), and mass spectrometry. A comprehensive analysis of experimental 1D and 2D NMR data, incorporating 1H iterative full spin analysis and higher-order multiplet simulation, revealed discrepancies with previously reported NMR data for this compound. Detailed examination of the 1H NMR spectrum's spin-spin coupling structure provided insights into the relative populations of the three staggered conformers around the C12–C13 bond at room temperature. The conformer populations were determined using the relationship between the experimental values for vicinal coupling constants and the estimated ones for the preferred staggered conformers, yielding a ratio of approx. 80:4:16 for anti, gauche, and gauche′-conformers, respectively. Possible reasons for the observed unevenly populated staggered conformers were also discussed. The antimicrobial activity of salvipisone was evaluated using in vitro and in silico methods. In vitro antimicrobial assays demonstrated that salvipisone exhibited the highest inhibitory effect against Staphylococcus aureus ATCC and Enterococcus faecalis ATCC (MIC = 3.125 μg/mL), followed by Bacillus subtilis ATCC (MIC = 6.25 μg/mL). In contrast, concentrations above 100 μg/mL were necessary to inhibit Escherichia coli ATCC and Klebsiella pneumoniae ATCC. In silico studies suggested that salvipisone, particularly its keto form, has significant potential for inhibiting the enzyme gyrase, highlighting its mechanism of antimicrobial action. Our findings highlight the promising antimicrobial and inhibitory properties of salvipisone, particularly against Gram-positive bacteria such as S. aureus.

Phytochemical Analyses and Antibacterial Activities of Jatropha tanjorensis J. L. Ellis and Saroja Leaves Extract against Clinical Pathogens

Aim: The aim of this study was to investigate the phytochemical and antimicrobial characteristics of leaf extracts from Jatropha tanjorensis plant against some selected clinical pathogens. Study Design: Experimental Study design (Quantitative). Place and Duration of Study: Sample: The bacteria were obtained from the stock culture of the Microbiology laboratory at LUTH, Idi-Araba, Lagos State and Department of Biological Sciences, Bells University of Technology, Ota, Ogun State. Methods: Fresh Jatropha tanjorensis leaves were obtained, identified, and then finely ground after being dried at room temperature. To obtain the extracts, two hundred grams (200g) of the leaves were macerated in one thousand milliliters (1000ml) of solvent. Phytochemical analyses were done on the extract utilizing suitable standard protocols. Using the agar well diffusion method, the leaf extracts' antibiotic sensitivity was assessed against selected bacteria, including Salmonella typhi, Pseudomonas aeruginosa, Bacillus subtilis ATCC 6633, Enterococcus faecalis FELAO97, Escherichia coli, Bacillus aureus ATCC 25923, and Bacillus aureus ATCC 25923. Results: The qualitative phytochemical analysis revealed that while phlobatannins were absent from all extracts, other compounds found included saponin, alkaloids, phenols, flavonoids, reducing sugars, terpenoids, steroids, and tannins. According to the quantitative phytochemical analysis, reducing sugars from methanolic extract had the lowest concentration (20.39 mg/100g) and flavonoids from hot water extract had the highest concentration (98.55 mg/100g). With a zone of inhibition of 19.83 mm against S. aureus, the cold-water extract exhibited the highest inhibitory effect, while the methanolic extract displayed the lowest zone of inhibition, 13.17 mm, against B. subtilis. When compared to other isolates, B. subtilis had the lowest MIC value of 10.24 mg/ml and other isolates had the highest MIC value of 20.48 mg/ml. A GC-MS analysis identified fifty-seven (57) bioactive compounds with 1, 2, 3-Benzenetriol having the highest percentage of 66.38%. Conclusion: This study suggests that Jatropha tanjorensis may be a potential antibacterial drug, but more thorough study and collaboration are still necessary.

Phytotoxicity, cytogenotoxicity and antimicrobial potential of extracts with gold-silver bimetallic nanoparticles obtained from pteridophyte spores

Investigating the toxicity of naturally occurring or synthesized nanoparticles for various applications is absolutely necessary for environmental protection and safety use. The aim of these research was to investigated the phytotoxicity, cytogenotoxicity and antibacterial potential of the extracts with gold-silver bimetallic nanoparticles (Au-Ag NPs) obtained from green synthesis in Asplenium scolopendrium L. and Dryopteris filix-mas (L.) Schott spores extracts. To our knowledge, this is the first report of the Au-Ag NPs phytosynthesis based on extracts obtained from fern spores. UV-Vis spectroscopy analysis of the samples revealed the maximum absorbance, characteristic of samples with bimetallic nanoparticles, which varied depending on the Au:Ag ratio. Energy-dispersive X-ray spectroscopy confirmed the presence and distribution of Au, Ag and other chemical elements. The presence of specific secondary metabolites in the extracts that helped in NPs biosynthesis stimulated growth processes. Good results were recorded for some Dryopteris filix-mas samples, correlated with a significantly increased mitotic index. Cell viability decreased significantly in three of the nanoformulations. Only extracts with Au-Ag NPs showed antimicrobial effect against Staphylococcus aureus ATCC 25923, Bacillus subtilis ATCC 6633 and Escherichia coli ATCC 8739. The testing of the antibacterial potential of these extracts must be extended to other bacterial strains and other microorganisms, the search of new antimicrobial resources being an urgent necessity nowadays.

Effect of electroinductive conditions on biofilm production capacity of some industrially important bacteria

Biofilms are intricate microbial deposits on biotic and abiotic surfaces, with significant medical and biotechnological implications. This study explored biofilm formation by Acetobacter aceti ATCC15973, Pseudomonas aeruginosa ATCC9027, Serratia marcescens ATCC14756, Gluconobacter oxydans ATCC19357, Rhodobacter sphaeroides ATCC17023, and Bacillus subtilis ATCC6633 on wood, glass, steel, PVC, and PET surfaces using qualitative methods. Effects of electrical stimulation (6V, 4.5A), magnetic fields (1000 G), and electromagnetic flux (5 mT) on biofilm formation were assessed via Crystal Violet Binding Assay. G. oxydans ATCC19357 exhibited highest adherence on PVC and wood (2.0145 and 2.402 log cfu/ml, respectively) under electrical stimulation. A. aceti ATCC15973 showed highest adherence on steel, PET, and glass (1.944, 0.9005, and 0.876 log cfu/ml). R. sphaeroides ATCC17023 demonstrated highest adherence on PVC, steel, PET, and glass (1.0895 to 1.7495 log cfu/ml) under magnetic induction; B. subtilis ATCC6633 had highest wood adherence (1.491 log cfu/ml). G. oxydans ATCC19357 showed highest overall adhesion with electromagnetic induction. PVC supported highest biofilm growth (39 %). Biophysical factors varied in enhancing biofilm formation, suggesting potential for bacterial immobilization technologies in bioremediation and industrial fermentation

ANTIBACTERIAL AND ANTIOXIDANT ACTIVITY OF COSMETIC CREAMS WITH EXTRACTS OF DRY FLOWERS AND FRUITS OF SAMBUCUS NIGRA L. - USE OF SAMBUCUS NIGRA L. AS A NON-TRADITIONAL CHEMICAL PRESERVATIVE

Natural ingredients rich in antioxidants and polyphenols in the forme of extracts, essential oils, organic acids have been used in the production of different cosmetic products. In the development of new cosmetic compositions, or the improvement of products already implemented in production, the evaluation of the user is of great importance, as it directly affects the demand for a given product. The present study aimed to produce phytocosmetic creams based on stearic acid with extracts of dry flower and fruit juice of Sambucus nigra L. (S. nigra) and to investigatein parallel their potential as substitutes for conventional preservatives. The obtained creams were determined for minimum inhibitory, and minimum bactericidal activity using three bacterial strains (Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC25923, Bacillus subtilis ATCC 6633). In addition, the antibacterial effect of creams against Escherichia coli (BW 28357) was determined. In our experiments we found that addition of dried flower extracts or elderberry fruit extracts from S. nigra in the emulsion does not disturb the compositional system. In conclusion, according to the results, the Sambucus nigra L. extracts from dry flowers and elderberry fruitsare appropriate for use in cosmetic emulsions that demonstated antioxidant stability and antibacterial properties.

Innovative approaches for amino acid production via consolidated bioprocessing of agricultural biomass.

Agricultural plantations in Indonesia and Malaysia yield substantial waste, necessitating proper disposal to address environmental concerns. Yet, these wastes, rich in starch and lignocellulosic content, offer an opportunity for value-added product development, particularly amino acid production. Traditional methods often rely on costly commercial enzymes to convert biomass into fermentable sugars for amino acid production. An alternative, consolidated bioprocessing, enables the direct conversion of agricultural biomass into amino acids using selected microorganisms. This review provides a comprehensive assessment of the potential of agricultural biomass in Indonesia and Malaysia for amino acid production through consolidated bioprocessing. It explores suitable microorganisms and presents a case study on using Bacillus subtilis ATCC 6051 to produce 9.56mg/mL of amino acids directly from pineapple plant stems. These findings contribute to the advancement of sustainable amino acid production methods using agricultural biomass especially in Indonesia and Malaysia through consolidated bioprocessing, reducing waste and enhancing environmental sustainability.

In vitro antimicrobial and antioxidant activities of Sambucus williamsii and Sambucus pendula

The present study aimed to compare the in vitro antimicrobial and antioxidant activities of Sambucus williamsii and Sambucus pendula. The antimicrobial activity of the two plants was evaluated using the disc diffusion and minimal inhibition concentration (MIC) method against three Gram-positive bacteria (Bacillus cereus ATCC 11778, Bacillus subtilis ATCC 9327 and Listeria monocytogenes ATCC 15313), four Gram-negative bacteria (Escherichia coli ATCC 15489, Psendomonas aeruginosa ATCC 27853, Pseudomonas fluorescens KCCM 41443 and Salmonella typhimurium KCCM 11862) and one yeast (Saccharomyces cerevisiae IFO 1950). The tested ether and ethyl acetate fractions of ethanol extract from Sambucus williamsii showed significant antimicrobial activity against Bacillus cereus and Pseudomonas fluorescens; conversely, the ether fraction of Sambucus pendula leaf showed no clear zone formation against any tested bacteria. In general, the fractions of the two Sambucus species exhibited a lower MIC against tested Gram-negative bacteria than the tested Gram-positive bacteria. The antioxidant activity was evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging assay. The results showed that the half inhibitory concentration (IC50) for the ethanol extract of Sambucus williamsii was the lower value, which means the greater antioxidant activity. On the other hand, the IC50 value of the hot water extract of Sambucus pendula was the lower value. The richness of the total polyphenol contents of the two Sambucus implies their potential as raw material sources for the pharmaceutical and cosmeceutical industries.

Green synthesis of ZnO nanoparticles using the mangosteen (Garcinia mangostana L.) leaf extract: Comparative preliminary in vitro antibacterial study

Abstract In the realm of public health, the rising threat caused by bacteria resistant to many drugs is a critical concern. In this work, we used the aqueous extract of mangosteen leaves to create zinc oxide (ZnO) nanoparticles (NPs) in an environmentally friendly manner. Through various analytical methods, we thoroughly characterized these biogenic ZnO NPs, including UV−visible, Fourier transform infrared, X-ray photoelectron spectroscopy, Raman spectroscopy, X-ray powder diffraction, field emission-scanning electron microscopy with energy dispersive X-ray and high resolution-transmission electron microscopy. ZnO NPs showed distinctive properties among different characterization techniques, including a small energy bandgap of 2.80 eV, a porous, a minimum crystalline size of 16.99 nm, an average particle size of 14.21 nm, and a spherical nanostructure. Additionally, we performed preliminary antibacterial experiments to assess ZnO NPs, copper oxide (CuO) NPs, and ZnO–CuO nanocomposites for antibacterial activity. Interestingly, ZnO NPs showed significant potential in suppressing the growth of Staphylococcus aureus ATCC BAA-1026, Bacillus subtilis ATCC 6633, Escherichia coli ATCC 25922, and Klebsiella pneumoniae ATCC 13883, with decreasing order of minimum inhibitory concentrations: S. aureus = B. subtilis (15.63 μg·mL−1) > E. coli (62.50 μg·mL−1) > K. pneumoniae (125.00 μg·mL−1). These results highlight the potential of biogenic NPs, particularly ZnO NPs, as effective agents against multi-drug-resistant bacteria.

The synergistic effect of periodate/ferrate (VI) system on disinfection of antibiotic resistant bacteria and removal of antibiotic resistant genes: The dominance of Fe (IV)/Fe (V)

The proliferation of antibiotic resistant genes (ARGs) and antibiotic resistant bacteria (ARB) caused by antibiotic abuse has raised concerns about the global infectious-disease crisis. This study employed periodate (PI)/ferrate (VI) (Fe (VI)) system to disinfect Gram-negative ARB (Escherichia coli DH5α) and Gram-positive bacteria (Bacillus subtilis ATCC6633). The PI/Fe (VI) system could inactivate 1 × 108 CFU/mL of Gram-negative ARB and Gram-positive bacteria by 4.0 and 2.8 log in 30 min. Neutral and acidic pH, increase of PI dosage and Fe (VI) dosage had positive impacts on the inactivation efficiency of ARB, while alkaline solution and the coexistence of 10 mM Cl-, NO3-, SO42- and 20 mg/L humic acid had slightly negative impacts. The reactive species generated by PI/Fe (VI) system could disrupt the integrity of cell membrane and wall, leading to oxidative stress and lipid peroxidation. Intracellular hereditary substance, including DNA and ARGs (tetA), would leak into the external environment through damaged cells and be degraded. The electron spin resonance analysis and quenching experiments indicated that Fe (IV)/Fe (V) played a leading role in disinfection. Meanwhile, PI/Fe (VI) system also had an efficient removal effect on sulfadiazine, which was expected to inhibit the ARGs transmission from the source.

Aktivitas Antibakteri dan Antioksidan dari Senyawa Bioaktif Asal Bakteri Endofit Tanaman Nyatoh (Palaquium amboinense B.)

Nyatoh plant (Palaquium amboinense B.) is native to Indonesia which is known to have the ability to produce potential secondary metabolites. The aim of this study was to evaluate the antibacterial and antioxidant activities from bioactive compounds produced by endophytic bacteria from nyatoh leaves. Five endophytic bacteria were tested against 4 targeted bacteria including Escherichia coli ATCC 8739, Pseudomonas aeruginosa ATCC 15442, Bacillus subtilis ATCC 19659, and Staphylococcus aureus ATCC 6538. Bacterial isolate which had the strongest antibacterial activity was then fermented and extracted. The corresponding extract was further tested on disc diffusion method, determination of Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) values, antioxidant evaluation, and analyzed for its bioactive compound components via GC-MS analysis. The results showed that one isolate, namely D1 can produce secondary metabolite which act as antibacterial and antioxidant potentials. This corresponding extract has the strongest MIC and MBC against B. subtilis with value of 39.5 and >78.1 µg/ml and exhibited antioxidant activity against 2,2-difenil-1-pikrilhidrazil (DPPH) with inhibition value of 85.37%. Based on GC-MS analysis, secondary metabolites derived from this potential extract contained some major active constituents including Tributyl acetylcitrate and bis (2-ethylhexyl) ester which might act as antibacterial and antioxidant agents.

Induction of antimicrobial, antioxidant metabolites production by co-cultivation of two red-sea-sponge-associated Aspergillus sp. CO2 and Bacillus sp. COBZ21

The growing spread of infectious diseases has become a potential global health threat to human beings. According to WHO reports, in this study, we investigated the impact of co-cultivating the isolated endophytic fungus Aspergillus sp. CO2 and Bacillus sp. COBZ21 as a method to stimulate the production of natural bioactive substances. (GC/MS)-based metabolomics profiling of two sponge-associated microbes, Aspergillus sp. CO2 and Bacillus sp. COBZ21, revealed that the co-culture of these two isolates induced the accumulation of metabolites that were not traced in their axenic cultures. By detection of different activities of extracts of Bacillus sp. COBZ21 and Aspergillus sp. CO2 and coculture between Bacillus sp. COBZ21 and Aspergillus sp. CO2. It was noted that the coculture strategy was the reason for a notable increase in some different activities, such as the antimicrobial activity, which showed potent activity against Escherichia coli ATCC 25,922, Staphylococcus aureus NRRLB-767, and Candida albicans ATCC 10,231. The antibiofilm activity showed significant biofilm inhibitory activity toward Bacillus subtilis ATCC 6633, Pseudomonas aeruginosa ATCC 10,145, and Staph aureus NRRLB-767, with activity up to 53.66, 71.17, and 47.89%, while it showed low activity against E. coli ATCC 25,922, while the antioxidant activity based on the DPPH assay showed maximum activity (75.25%). GC-MS investigations revealed the presence of variable chemical constituents belonging to different chemical categories, which reflected their chemical diversity. The main components are (+-) cis-Deethylburnamine (2.66%), Bis(3,6,9,12-tetraoxapentaethylene) crowno-N,N,N’,N’-tetra methylpphanediamine (2.48%), and 11-phenyl-2,4,6,8-tetra(2-thienyl)-11-aza-5,13-dithiaeteracyclo[7.3.0.1(2,8)0.0(3,7)] trideca-3,6-diene-10,12,13-trione (3.13%), respectively, for Bacillus sp. axenic culture, Aspergillus sp. CO2, Aspergillus sp. CO2, and Bacillus sp. COBZ21 coculture. By studying the ADME-related physicochemical properties of coculture extract, the compound showed log Po/w values above 5 (8.82). The solubility of the substance was moderate. In order to provide a comprehensive definition of medicinal chemistry and leadlikness, it is important to note that the latter did not meet the criteria outlined in the rule of three (RO3). The toxicity prediction of the coculture extract was performed using the ProTox II web server, which showed that the selected compound has no pronounced toxicity.

Antibacterial activity of Lactic acid bacteria strains Isolated from Marine Algae against Pathogenic Bacteria

This work aims at evaluating the antibacterial activity of 14 lactic acid bacteria (LAB) strains isolated from two species of marine algae (Sargassum muticum and Ulva lactuca) against six pathogenic bacteria, including Escherichia coli ATCC 10536, Staphylococcus aureus ATCC 9144, Bacillus subtilis ATCC 6633, Bacillus cereus ATCC 33019, Bacillus sp. CIP 104717, and Salmonella sp. LAB inhibitory capacity was assessed by using agar well diffusion test. Results showed that significant inhibitory zones of 30.33, 23.33, 13, 12, 9, and 8 mm were obtained against E. coli, B. subtilis, B. cereus, Bacillus sp., Salmonella sp. and S. aureus, respectively. These findings underscore the potential use of marine LAB for producing antibacterial substances, suggesting their applications in biotechnological processes targeting food spoilage and human infections.

Silver nanoparticle synthesis by biogenic reduction method and investigation of antimicrobial, antibiofilm, anticancer activities

It is very important to use the green synthesis approach that uses living things and plants. Using the biogenic reduction technique, silver nanoparticles were synthesized from the R. aculeatus plant for this research. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy, X-ray diffraction (XRD), and UV-vis spectroscopy was used to characterize the produced AgNPs (FT-IR). After the In this study, R. aculeatus plant extract and biogenically formed AgNPs were investigated for their potential antibacterial, antibiofilm and anticancer abilities. AgNPs were characterised using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and UV-vis spectroscopy (UV-VIS). According to the Debye Scherrer formula, the particle size was found to be 32.56 nm. Disc diffusion and microdilution methods were used to investigate the antibacterial activity. In the disc diffusion study, the best results were obtained from the extract and AgNP. In the tests using plant extracts, Staphylococcus aureus ATCC 25923 showed the lowest antibiofilm activity, while Bacillus subtilis and Enterobacter aerogenes ATCC 13048 showed the highest activity. Salmonella infantis was most affected by AgNP, while Escherichia coli CFAI ATCC 25922 was least affected. Biogenically synthesised AgNPs were also investigated in cytotoxic activity studies. It was found to have the lowest concentration value on MCF-7 and HUVEC cell lines at the determined concentrations. The extract did not have any cytotoxic effect on MCF-7 cell line. HUVEC cell line showed the lowest cytotoxic activity of 10-3 g/mL. The antibacterial, antibiofilm and anticancer properties of R. aculeatus plant extract and biogenically produced AgNPs have been the subject of an important study. Furthermore, the comparison of the effects of plant extract and AgNPs on breast cancer cell lines and healthy cell lines provides a rich scientific material.

The modification of nisin with homocysteine thiolactone and its effect on antimicrobial activity.

The aim of the present study is to make an important contribution to the literature by focusing on the preparation of the N-homocysteine conjugate of nisin and evaluating the effect of the N-homocysteinylation reaction on its antimicriobial activity. The modification process was monitored using both acetic acid urea polyacrylamide gel electrophoresis (AAU-PAGE) and tricine sodium dodecyl sulphate polyacrylamide gel electrophoresis (tricine SDS-PAGE). The antibacterial effectiveness of modified nisin was assessed against Staphylococcus aureus ATCC 6538, Enterococcus faecium ATCC 9097, Bacillus subtilis ATCC 6633, Lactococcus lactis ssp. cremoris AÜ, Listeria monocytogenes NCTC 5348, and Escherichia coli RSKK. Optimal conditions for achieving the highest N-homocysteinylation degree (6.30%) were determined as 6 mg/mL nisin, 150 mM homocysteine thiolactone, 150 rpm shaking rate, pH of 3.0, and a reaction time of 6 h. The modified nisin obtained did not have a significant inhibitory effect on the strains tested except E. faecium. E. faecium was inhibited by the modified nisin and its antibacterial activity was determined as approximately 10% of the antibacterial activity of unmodified nisin. On the other hand, hydrolysis of nisin by trypsin and thermolysin resulted in significant specific side chain modifications induced by the homocysteine-thiolactone reaction, especially at Lys12 and Lys22. The results provide valuable insights into the potential of N-homocysteinylation to improve the antibacterial properties of nisin and also suggest that the effects of specific modifications identified during the modification process should be investigated.

Biosynthesis and characterization of silver nanoparticles from Punica granatum (pomegranate) peel waste and its application to inhibit foodborne pathogens

Polyphenolics have been predicted to effectively develop antimicrobial agents for the food industry as food additives and promote human health. This study aims to synthesize pomegranate peel extract (PPE) with silver nanoparticles (AgNPs) against eight foodborne pathogens. Multispectroscopic analysis of UV–vis spectroscopy, Zeta potential, Fourier transform infrared (FTIR) and scanning electron microscopy (SEM) analysis were used to characterize the interaction between PPE and AgNPs. Eight foodborne pathogenic strains (six bacterial and two fungal strains) Bacillus subtilis ATCC 6633, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 8379, Klebsiella pneumoniae ATCC 00607, Salmonella typhi DSM 17058, Shigella sonnei DSM 5570, Aspergillus flavus ATCC 9643, and Rhizopus oryzae ATCC 96382 were used to test the inhibitory potential of PPW-AgNPs. The reaction colour of PPE-AgNPs from yellow to brown indicated that the nanoparticles were successfully formed. The UV absorption of PPE-AgNPs was detected at 440 nm of 0.9 SPR. SEM image of PPE-AgNPs exhibited spherical shapes with a zeta potential of − 20.1 mV. PPE-AgNPs showed high antimicrobial activity against all tested strains. The highest inhibition activity of PPE-AgNPs was recorded for the B. subtilis strain followed by K. pneumonia, while the highest resistance was noticed for R. oryzae. The components of pomegranate peel were analyzed using gas chromatography–mass spectrometry (GC–MS). The major constituents of pomegranate peel is phenol (51.1%), followed by Isocitronellol (19.41%) and 1-Propanol, 2-(2-hydroxypropyl)- (16.05%). PPE is key in the simple, eco-friendly green synthesis of extracellular stable AgNPs as an alternative source for harmful chemical disinfectants.

Investigation of Lactobacillus spp. bacteria in infants consuming breast milk and formula and determination of some probiotic characters

Objectives: It was aimed to investigate some probiotic properties of Lactic Acid Bacteria (LAB) isolated from stool samples taken from 45 healthy 0-4 month old babies, who did not take antibiotics or probiotic supplements in the last 3 months, and who did not have any health problems. Methods: Six different species were obtained from 21 isolates selected by the method of Mass Spectrometry (MALDI-TOF MS). Results: The most common strain was Lactobacillus rhamnosus with a rate of 59%, followed by Lactobacillus paracasei with a rate of 13.6%. Vancomycin, tetracycline, gentamicin, netilmicin, tobramycin, penicillin, ampicillin, teicoplanin and amikacin antibiotics were used to evaluate the antimicrobial activities of the strains. In our study, while all strains were resistant to the antibiotic amikacin, they were sensitive to tetracycline, penicillin, gentamicin, netilmicin, teicoplanin, vancomycin, ampicillin and tobramycin antibiotics. In the evaluation of the antagonistic activities of LAB, 6 different pathogens (Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 6538, Bacillus subtilis ATCC 6633, S. aureus ATCC 25923, Candida albicans ATCC 10231, Listeria monocytogenes ATCC 19111) were used and it was determined that the strains showed antimicrobial effects on all pathogenic microorganisms. Cholesterol assimilation abilities, T21 and T22 strains achieved the highest cholesterol assimilation rate of 39.1%. Conclusions: It is thought that most of the isolated strains have probiotic potential, and especially Lactobacillus gasseri T21 and L. paracasei T22 strains may be probiotic strains that can be used in the production of preparations alone or together with other Lactobacillus strains.

Synthesis, Antibacterial Activities and Theoretical Study of Polyhydroquinoline Derivatives

AbstractIn the present study, novel bis‐Schiff base derivatives of polyhydroquinoline were synthesized through Hantzsch condensation reaction in excellent yields. Initially, a mixture of dimedone, ethyl acetoacetate, ammonium acetate and esterified aldehydes were refluxed in ethanol for 7–9 hrs. Then, hydrazine hydrate was treated with obtained polyhydroquinoline to form bis‐hydrazide of corresponding polyhydroquinoline. Finally, the bis‐hydrazide was independently refluxed with substituted aromatic aldehydes to get desired bis‐Schiff base derivatives of polyhydroquinoline. The new derivatives were confirmed by modern spectroscopic techniques such as 1H‐NMR, 13C‐NMR and HR‐ESI‐MS. The targeted compounds were evaluated for their antibacterial activity using disc diffusion method. The derivative with four OH‐group was found more effective against Bacillus megaterium, Bacillus subtilis IM, Bacillus subtilis ATCC, Salmonella enterica and Proteus vulgaris FMC II with zone of inhibition 8.3, 7.6, 7.3, 6.6 and 6.3 mm, respectively. DFT study of targeted compounds were performed on both materials studio and Gaussian 09 package, which showed good agreement with experimental data. The NLO of synthesized compounds were calculated and consider good candidates for NLO. The global reactivity, NBO and 1H‐NMR correlation were also studied, which showed good agreement. The cheap reagents, short reaction time and excellent yields are some features of current work.

Evaluation of Antimicrobial Effects of Fresh and Dried Fruit in Turkish Tombul Hazelnut Variety

Objective: The aim of the study was to determine the antimicrobial properties of fresh and dried fruits of Turkish Tombul hazelnut (Corylus avellana L.) variety.
 Materials and Methods: The Turkish Tombul hazelnuts used in the experiment were obtained from Helvacı Village/ Düzköy /Trabzon. Fresh hazelnuts were harvested in 2023, while dried hazelnuts were collected in 2022. The dried hazelnuts were dried at 105°C until they attained a consistent weight. This section was not created for fresh hazelnuts. The treated micelle was extracted for 4 hours with 100 mL of Ethyl alcohol (EtOH) for every 10 g of both the fresh and dried hazelnut samples crushed. The micelle (hazelnut+oil+solvent mixture) was filtered through coarse filter paper to remove particles before being blown away with a Rotary evaporator (Heidolph, Germany). The resulting extracts were used for antimicrobial testing. Antimicrobial activity of the strains was evaluated against Pseudomonas aeruginosa ATCC 27853, Enterobacter cloaceae ATCC2468, Enterococcus feacalis ATCC51299, Escherichia coli ATCC2471, Klebsiella pneumoniae ATCC700603, Salmonella typhimurium ATCC13311, Serretia marcescens ATCC13880, Staphylococcus epidermis ATCC14990, Staphylococcus aureus ATCC25923, Bacillus subtilis ATCC 6633, Streptococcus faecalis ATCC 9790, Yersinia pestis ATCC 19428 and Candida albicans ATCC10351. One-way analysis of variance (ANOVA) was run to determine any significant differences in the study groups by Duncan multiple range test was performed through SPSS.
 Results: Dried hazelnut extract was effective in all of them, while fresh hazelnut extract was only effective on Candida albicans ATCC10351 and Klebsiella pneumoniae ATCC700603 (F (3, 8) = 65.45, p