Free Supernatant Research Articles

Influence of Enterococcus faecium, a probiotic component, on ion channels in colon cancer

Aims: This study aimed to investigate the effect of probiotic bacterium Enterococcus faecium (E. faecium) on the gene expression of ion channels in colon cancer cells. Methods: The cytotoxic effect on SW480 colon cancer cell line was analyzed by MTT cell proliferation test using E. faecium bacterial cell culture free supernatants. The effect of E. faecium on ion channel genes in SW480 cells was determined by qRT PCR analysis. STRING analysis was used to reveal protein-protein interactions of ion channel proteins. Bioinformatic analysis of healthy and colon cancer patient data on ion channels was revealed with GEPIA platform. Results: The SW480 cell line's viability was enhanced by E. fecieum bacterial cell culture free supernatants dosages of 0.5 and 1.09 mg/ml, but it dramatically declined between 2.187 and 17.5 mg/ml doses, according the MTT study. Analysis of gene expression revealed that the TRPV2 and TRPM8 genes had significantly increased. The examined ion channel proteins were discovered to be substantially linked to one another based on STRING analysis. The TRPM2 gene we looked at revealed a notable rise in colon cancer patients based on data from both healthy and colon cancer patients on the GEPIA platform. Conclusion: E. faecium has been shown to have many beneficial effects on health. Our study has shown that it also has an effect on ion channels in cancer cells and that ion channels are of great importance for cell survival and death.

Biofabrication, characterization and unveiling the biological potential of zinc oxide nanoparticles from bacterium Bacillus pacificus KR A1

The utilization of cell free supernatant for synthesizing nanomaterials has been considered as an innovative approach. This investigation aims to fabricate a ZnO NPs using the cell free supernatant of Bacillus pacificus KR A1. The prepared nanomaterials were systematically characterized by UV-DRS, FT-IR, XRD, HR-TEM, XPS and elemental mapping (EDX) techniques. The optical band gap energy of Bacillus pacificus ZnO NPs (Bp-ZnO NPs) was observed as 3.25 eV. The XRD analysis revealed that Bp-ZnO NPs were hexagonal wurtzite structures with 50 nm crystallite size. Furthermore, XPS data revealed the elements present in Bp-ZnO NPs. The HR-TEM analysis revealed that most of the particles were spherical in shape with an average calculated particle size of 20 nm with a lattice fringe range of 0.246 nm. In addition, Bp-ZnO NPs showed promising antibiofilm properties against Bacillus cereus and Vibrio alginolyticus at 100 μg/mL concentration. Furthermore, MDA-MB-231 cells treated with an IC50 concentration showed changes in cell morphology including apoptosis, cell shrinkage and nuclear fragmentation. However, HUVEC cells treated with higher concentration (40 µg/mL) of Bp-ZnO NPs displayed less toxicity and 86.3 % of cells are viable. In summary, Bp-ZnO NPs could serve as a promising material for biomedical claims.

Cyanobacterial consortia as biostimulant for germination of Zea mays seeds

Cyanobacterial extracts are known to be rich in several plant growth promoting metabolites as well as phytohormones. Indole 3 acetic acid is one of the phytohormones that are known to be promoting seed germination. On the basis of the ability of three cyanobacterial species Westiellopsis sp. TPR-29, Hapalosiphon sp. Ryu2-7DN_D3 and Chlorogloeopsis fritschii PCC 6912 to produce IAA, their cell free supernatant were tested for induction of germination in Zea mays (Maize) seeds. The seeds were treated with cell free extracts of 15 days old cyanobacterial cultures for 24 and 48 hours.

Antibacterial activity of lactic acid bacteria isolated from traditionally fermented food against food pathogen

Aim: To evaluate the antibacterial activity of lactic acid bacteria against selected food pathogens (Escherichia coli and Staphylococcus aureus). Method: A total of twenty (20) traditionally fermented food samples were purchased from a market in Owerri metropolis. Isolation and identification of lactic acid bacteria (LAB) were conducted using standard microbiological techniques. LAB was identified using standard morphological and biochemical tests. They were tested against food pathogens using the Agar well diffusion method. Results: The isolated lactic acid bacteria include Lactobacillus fermentum, Lactobacillus acidophilus, Lactobacillus casei and Lactobacillus plantarum and were label as SP1, SP2, SP3, and SP4 respectively. The isolated LAB species had a considerable inhibitory effect on food borne pathogens. Cell free supernatant of four species were tested for antagonistic activity at 24hrs and 48hrs incubation time. Cell free supernatant from 48hrs broth of SP1 showed the highest zone of inhibition on Escherichia coli (28mm) while the cell free supernatant from 24hrs broth of SP4 showed the lowest zone of inhibition on Staphylococcus aureus (13 mm). Conclusion: The antimicrobial activity increases with time. LAB demonstrated high antimicrobial properties against food borne pathogens. This potential can be employed as starters in food industry to inhibit food spoilage microbes and contaminants.

Antimicrobial activity of Lactobacillus cell free supernatant against Salmonella Enteritidis and Infantis

Cell-free supernatants (CFS) produced by lactic acid bacteria (LAB) have been characterized as natural antagonists of important pathogens, including Salmonella. Their bacteriostatic or bactericidal properties have been reported to serve as an alternative to antibiotics by minimizing problems related to antimicrobial resistance. This study aimed to evaluate the antimicrobial activity of CFS of 4 selected LAB strains belonging to Lacticaseibacillus paracasei (2 strain), Limosilactobacillus reuteri (1 strain), and Lacticaseibacillus rhamnosus (1 strain) species against Salmonella Enteritidis and Infantis serovars by the agar-well diffusion method. Cell-free culture media of lactic acid bacteria were used in either crude CFS (acidic) and neutralized form (NCFS) to also understand non-pH-dependent antimicrobial potential. All crude CFSs were found to exhibit antimicrobial activity against pathogens, ranging from moderate to strong. After pH neutralization, the crude CFS of L. paracasei (2 strains) lost their antimicrobial activity, except for the crude CFS produced by L. reuteri and L. rhamnosus. However, there was a significant decrease in the level of anti-Salmonella activity of L. rhamnosus NCFS. It was determined that L. reuteri NCFS continued to show antimicrobial activity at levels similar to the effects of crude CFS. It is thought that the antibacterial activity of L. reuteri and L. rhamnosus CFS determined in the research does not depend only on their acidity and that the chemical characterization of the postbiotics, which is the source of this antimicrobial activity, should be evaluated.

IN VITRO AND IN VIVO INVESTIGATION OF PROBIOTICS ISOLATED FROM HUMAN MILK

People all over the world are embracing probiotics as a result of growing awareness of the health advantages connected to ingesting living bacteria. Proper administration of probiotics has been shown to provide numerous health advantages to the host. The Lactobacillus genus, which naturally resides in the mucosal linings of humans and animals, and it is essential for stabilizing the gastrointestinal tract and protecting intestinal health from infections. There has been a great deal of interest in their potential uses as probiotics, mucosal vaccine vectors, and agents regulating metabolic activities. The present study aimed at isolating and characterizing novel probiotics from human milk and functionally assessing them in vivo for their physiological, enzymatic and antimicrobial activity. Probiotic isolates from human milk were amylolytic, proteolytic and lipolytic and were found to be tolerant to low pH of 3.5, 10% salt and 0.3% bile salt. Primary method of cross streaking and secondary streaking by agar diffusion method revealed antagonistic activity of the isolates against tests pathogens of humans viz., S. aureus Newman, P. fluorescens, S. epidermis and S. aureus. Antibiofilm activity of probiotic isolates in vivo against P. fluorescens and S. aureus Newman indicated that the metabolites present in the Cell Free Supernatant (CFS) of the isolates may have the ability to inhibit the formation of biofilm of pathogenic strains. The most efficient probiotic isolates was identified as Weissella confusa and the NCBI GenBank accession number was obtained. The infected mice administered with probiotic isolate Weissella confusa PS17 showed reduced mortality rate than the mice infected with pathogenic strain S. aureus Newman, thus indicating that probiotic strain boosted the immune response of the mice. The Serum uric acid levels was normalised after the infected mice was treated with W. confusa PS17 and this in turn enhanced the survival rate of mice. The present study indicates that isolate W. confusa PS17 can be a promising candidate in improving the condition of health.

Identification of novel antimicrobial compounds in colostrum-associated Lactiplantibacillus plantarum ZFS 1 and 2 by integrating in vitro, machine learning and bioinformatics approaches

Current study was designed to identify safe, novel antimicrobial compounds in the cell free supernatant of two colostrum-associated probiotic strains, “Lactiplantibacillus plantarum, ZFS-1 and ZFS-2” by using in vitro, advanced machine learning, and bioinformatics approaches. The cell free supernatant (CFS) and ethyl acetate fraction of CFS of both isolates, were evaluated for antagonistic properties against four pathogens. The antioxidant and anti-inflammatory properties of ethyl acetate fraction were also assessed in vitro. The secondary metabolites in the ethyl acetate fraction of CFS were identified by Gas chromatography-Mass spectrometry. Further, Machine learning techniques, including models such as Support Vector Machine, k-Nearest Neighbor, Naive Bayes, and Random Forest, were applied to analyze the data using Python. Molecular descriptors were calculated using the RDKit library and further analyzed through Principal Component Analysis. Among the models, the RF achieved 100% accuracy on the test set, with a 10-fold cross-validation accuracy of 93.84%. Additionally, docking analysis was conducted to evaluate the binding affinities between the identified metabolites and microbial proteins. The CFS of both isolates displayed inhibition zones of 12–18 mm, while ethyl acetate fraction exhibited ZI of 16–30 mm against four pathogens. Minimal Inhibitory and bactericidal concentrations ranged from 3.12 to 6.5 and 6.5–12.5 mg/mL, respectively. Significant differences (p < 0.05) were noted in their antimicrobial and antioxidant efficiencies. Acridine, 1H-Phenalen-1-one, and (NE)-N-[(4-amino-1,2,5-oxadiazol-3-yl)-(triazirin-1-yl)methylidene]hydroxylamine in CFS of Lactiplantibacillus plantarum strain ZFS-1 and 5,6,7,8-tetrahydro-2-methoxy-5,5-dimethyl-1,4-Anthracenedione in CFS of strain ZFS-2 were identified as novel antimicrobial compounds. The compounds are validated as potentially safe drug candidates employing comprehensive molecular docking analyses.

Effect of the Bioprotective Properties of Lactic Acid Bacteria Strains on Quality and Safety of Feta Cheese Stored under Different Conditions.

Lately, the inclusion of additional lactic acid bacteria (LAB) strains to cheeses is becoming more popular since they can affect cheese's nutritional, technological, and sensory properties, as well as increase the product's safety. This work studied the effect of Lactiplantibacillus pentosus L33 and Lactiplantibacillus plantarum L125 free cells and supernatants on feta cheese quality and Listeria monocytogenes fate. In addition, rapid and non-invasive techniques such as Fourier transform infrared (FTIR) and multispectral imaging (MSI) analysis were used to classify the cheese samples based on their sensory attributes. Slices of feta cheese were contaminated with 3 log CFU/g of L. monocytogenes, and then the cheese slices were sprayed with (i) free cells of the two strains of the lactic acid bacteria (LAB) in co-culture (F, ~5 log CFU/g), (ii) supernatant of the LAB co-culture (S) and control (C, UHT milk) or wrapped with Na-alginate edible films containing the pellet (cells, FF) or the supernatant (SF) of the LAB strains. Subsequently, samples were stored in air, in brine, or in vacuum at 4 and 10 °C. During storage, microbiological counts, pH, and water activity (aw) were monitored while sensory assessment was conducted. Also, in every sampling point, spectral data were acquired by means of FTIR and MSI techniques. Results showed that the initial microbial population of Feta was ca. 7.6 log CFU/g and consisted of LAB (>7 log CFU/g) and yeast molds in lower levels, while no Enterobacteriaceae were detected. During aerobic, brine, and vacuum storage for both temperatures, pathogen population was slightly postponed for S and F samples and reached lower levels compared to the C ones. The yeast mold population was slightly delayed in brine and vacuum packaging. For aerobic storage at 4 °C, an elongation in the shelf life of F samples by 4 days was observed compared to C and S samples. At 10 °C, the shelf life of both F and S samples was extended by 13 days compared to C samples. FTIR and MSI analyses provided reliable estimations of feta quality using the PLS-DA method, with total accuracy (%) ranging from 65.26 to 84.31 and 60.43 to 89.12, respectively. In conclusion, the application of bioprotective LAB strains can result in the extension of feta's shelf life and provide a mild antimicrobial action against L. monocytogenes and spoilage microbiota. Furthermore, the findings of this study validate the effectiveness of FTIR and MSI techniques, in tandem with data analytics, for the rapid assessment of the quality of feta samples.

Probiotic Lactobacillus salivarius mediated synthesis of silver nanoparticles (AgNPs-LS): A sustainable approach and multifaceted biomedical application

Biogenic synthesis of silver nanoparticles (AgNPs) has emerged as an eco-friendly and sustainable approach with diverse biological applications. This study presents synthesis of AgNPs-LS using a probiotic strain Lactobacillus salivarius (L. salivarius) and explores their multifaceted biological activities, including antibacterial, antibiofilm, anti-quorum sensing, antifungal, antioxidant, anticancer, anticoagulant and thrombolytic properties. The biosynthesis of AgNPs-LS was successfully achieved using L. salivarius cell free supernatants, resulting in well-characterized nanoparticles as confirmed by UV–Vis spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, transmission electron microscopy (TEM) and dynamic light scattering (DLS) and zeta potential analysis. The AgNPs-LS demonstrated potent antibacterial activity against different pathogenic bacteria (C. violaceum, P. aeruginosa, S. aureus, E. coli and S. marcescens), emphasizing their potential in combating bacterial infections. Moreover, these AgNPs-LS were effective in inhibiting biofilm formation (>60 % at 1/2 MIC), a key mechanism of bacterial virulence, highlighting their utility in preventing biofilm-related infections. AgNPs-LS exhibited anti-quorum sensing activity, disrupting bacterial communication systems and potentially reducing virulence factor such as, violacein production in C. violaceum, pyocyanin production in P. aeruginosa and prodigiosin production in S. marcescens. Additionally, AgNPs-LS also exhibited notable antifungal activity towards a different pathogenic fungus (F. proliferatum, P. purpurogenum, A. niger and R. stolonifer). In terms of health applications, the AgNPs-LS displayed significant antioxidant activity, effectively scavenging DPPH• (IC50 = 42.65 μg/mL) and ABTS•+ (IC50 = 53.77 μg/mL) free radicals. Furthermore, AgNPs-LS showed cytotoxicity against breast cancer cells (MCF-7) (IC50 = 52.29 μg/mL), positioning them as promising candidates for cancer therapy. Moreover, AgNPs-LS were also shown promising anticoagulant and thrombolytic activities under practical conditions. Therefore, the biogenic synthesis of AgNPs-LS using L. salivarius offers a sustainable and cost-effective route for producing AgNPs with an array of biological activities. These AgNPs-LS have the potential to address various challenges in healthcare, ranging from antimicrobial, anticancer applications to biofilm inhibition, antioxidant therapy, anticoagulant and thrombolytic agents.

Anti-biofilm and anti-virulence potential of cell free supernatant of Akkermansia muciniphila against Salmonella

Akkermansia muciniphila is one of the commensals residing within the mammalian gut and co-evolving with the host. Numerous studies have demonstrated the benefits of A. muciniphila in ameliorating metabolic disorders, while little is known about the antimicrobial potential of A. muciniphila against pathogens. Here, we examined the antimicrobial and anti-virulence properties of cell free supernatant (CFS) of A. muciniphila against Salmonella Typhimurium. CFS retarded bacterial growth and inhibited the motility of S. Typhimurium SL1344 and S. Typhimurium 14028. CFS dose-dependently reduced cell hydrophobicity and auto-aggregation of both strains. Also, CFS from A. muciniphila significantly attenuated biofilm formation. Compared with untreated bacteria, CFS-treated bacteria significantly decreased adhesion and invasion to Caco-2 cells, and reduced intracellular survival in macrophages. CFS maintained antimicrobial properties after treatment with high temperatures and various proteases, while it lost its antimicrobial activity after pH neutralization. Gas chromatography-mass spectrometry (GC-MS) confirmed that A. muciniphila produced a certain amount of acetate and propionate, and ultra-high-performance liquid chromatography-mass spectrometry (UHPLC-MS) identified other organic acids and metabolites in CFS. In summary, CFS from A. muciniphila exhibited anti-biofilm and anti-virulence properties against Salmonella and could be potentially utilized in the food industry for controlling Salmonella contamination and reducing infection.

Identification of new phylogenetic lineage of Lasiodiplodia causing leaf spot and tip necrosis causing agent on Aloe vera in Sri Lanka and screening eco-friendly control measures

Aloe vera, a member of the Asphodelaceae family, is renowned globally for its medicinal properties and widespread applications in cosmetics, pharmaceuticals, and food production. In Sri Lanka, both cultivated and wild A. vera are susceptible to leaf spot and tip necrosis. The present aims to identify the causative agent of this disease and screen the effectiveness of various natural substances in disease control. Disease incidence was assessed in both cultivated fields and wild habitats, and the results showed a higher percentage in the wild. Isolates obtained from symptomatic leaves were identified as members of Lasiodiplodia based on morphological studies. The phylogenetic analysis, which combined sequences from the Internal Transcribed Spacer (ITS) region and a segment of the calmodulin (cmdA) gene, suggested that the isolates might represent a new lineage within the genus Lasiodiplodia. These isolates appeared to share a common ancestor with Lasiodiplodia hormozganensis. Koch's postulates validated the pathogenicity of the isolates. Natural substances, namely marine algal extracts, plant extract and cell-free supernatants (CFSs) of bacteria, were tested against the isolates. CFSs of Pseudomonas fluorescens and Bacillus megaterium showed significantly higher inhibition on conidial germination compared to the tested commercial fungicide. Further, CFS of P. fluorescens revealed the notable effectiveness on the development of leaf spot and tip necrosis on the leaf compared to the tested fungicide. These findings underscore the potential of P. fluorescens CFS in managing A. vera diseases caused by the isolates of Lasiodiplodia in Sri Lanka.

Isolation and Characterization of Bacteriocin Producing Levilactobacillus brevis Strain ABRIINW-K from Buffalo Dung

Bacteriocins are proteins secreted by many species of bacteria to inhibit other bacteria, thus eliminating competitors to gain resources. Bacteria from the Lactobacillus group are known for their applications as probiotics and food preservatives. They have earned a reputation for producing substances that inhibit the growth of other microorganisms, which include organic acids, diacetyl, and bacteriocins. Produced by the ribosomes, bacteriocins are cationic proteins that inhibit other bacteria coexisting within a shared ecological habitat. Due to their potential uses in a variety of applications large-scale production of Bacteriocins would be necessary. The study aimed to identify and characterize Lactobacillus bacteria that produce potent bacteriocins and to analyze the antimicrobial activity and stability of the isolated bacteriocin under various physical and biochemical conditions. A total of 50 samples including buffalo dung, cheese, and rhizospheric region of plants were screened to isolate 8 Lactobacillus Li-1, Li-2, Li-3, Li-4, Li-5, Li-6, Li-7, and Li-8, confirmed by gram staining and other biochemical tests. The cell free supernatant from the Li-3 strain showed higher inhibition of Escherichia coli and Staphylococcus aureus, as compared to the other isolated strains. Li-3 strain was further identified as Levilactobacillus brevis strain ABRIINW-K by 16S rRNA gene sequencing. The bacteriocin isolated from this strain is a thermostable peptide (~6kDa), which is characteristic of class II bacteriocins, with potent antibacterial activity against Lactobacillus rhamnosus, Escherichia coli, and Salmonella enterica.

Protection capacity of Lactiplantibacillus plantarum 83114 against contamination of dry pet food with Aspergillus flavus

A wide range of pet food types are available on the market and one of the most common ingredients of dry food are cereals, vectors of harmful mycotoxins. Mycotoxins are toxic secondary fungal metabolites that contaminate dry pet food and their levels remain stable during food processing. This has a direct effect on the quality of the product and on animal health. Lactiplantibacillus plantarum 83114 is a probiotic strain isolated from traditional fermented milk with proven antifungal activity in different matrix. This study investigated the antifungal activities of this strain against contamination of dry pet food with a mycotoxigenic Aspergillus flavus strain. The antifungal activity was assessed using a complete culture of viable L. plantarum 83114, cell free supernatants (CFS), and non-viable cells (postbiotics). The CFS of L. plantarum CIDCA 83114 (pH 4.04) exhibited a high germination reduction rate (GR 94.7 %). However, the neutralized CFS (pH 7.0) lost approximately 60 % of its inhibitory capacity. L. plantarum CIDCA 83114 CFS and postbiotic treatments at 50 % exerted a total fungal growth inhibition, observed in a growth rate (KD) of zero. The viability of L. plantarum 83114 inoculated in dry pet food decreased by one logarithmic order after the first week of storage and, by the second week, no viable cells were detected. The DNA concentration of A. flavus in dry pet food supplemented with the probiotic strain remained consistently low and stable throughout the storage period. Lactiplantibacillus plantarum 83114 played a crucial role in inhibiting fungal growth and could act as a biopreservative agent in pet food.

Lactiplantibacillus plantarum exerts anticancer effects and increase the chemosensitivity of 5-fluorouracil against oral cancer cells in vitro

Introduction: Probiotics are used to provide health benefits and can improve the immune response. They can also target cancer cells directly with anticancer effects through various mechanisms. In this study, Lactiplantibacillus plantarum (basonym: Lactobacillus plantarum) strain MCC 3016 and its postbiotic metabolites/cell free supernatant (CFS) were used against Cal27 oral cancer cells in vitro. Methods: Standard assays were employed to investigate the effect of Lpb. plantarum on cell viability, proliferation, migration, and clonogenicity of Cal27 cells. The mechanism of action was assessed by measuring the levels of reactive oxygen species (ROS), interleukins (IL)-6 and IL-8, tumor necrosis factor-α (TNF-α), as well as the expression of Ki67, vascular endothelial growth factor (VEGF), p53 and caspase-3. Further, the effect of Lpb. plantarum and its CFS on the cytotoxicity of chemotherapy drug 5-fluorouracil (5-FU) was evaluated using cell viability assays. Results: Cal27 cells treated with Lpb. plantarum and its CFS showed a significant decrease (P &lt; 0.01) in cell viability, proliferation, migration, and clonogenicity, along with increased levels of ROS and induced apoptosis. It significantly reduced IL-6, IL-8, TNF-α, and VEGF levels and upregulated p53 and caspase-3 expression. The postbiotic metabolites also showed similar effects on Cal27 cells. Furthermore, the cytotoxic effect of 5-FU on Cal27 cells was enhanced by Lpb. plantarum and its CFS treatment. Conclusion: Lpb. plantarum MCC 3016 and its postbiotic metabolites exhibited promising anticancer effects on oral cancer cells and improved drug efficacy, demonstrating their potential therapeutic value in oral cancer therapy.

Antifungal activity of metabolites of Weissella cibaria KM14 isolated from traditional Korean food kimchi against three spoilage fungi

The Weissella genus has recently gained popularity due to its antifungal and probiotic properties. In this study, the antifungal activity of isolate KM14 of Weissella cibaria on Aspergillus fumigatus, Penicillium expansum, and P. oxalicum were evaluated by the overlay method and microplate inhibition analysis; results showed that the bacterium had a high inhibition rate against these three fungi, ranging from 99.4 to 94.3%. The evaluation of the antifungal activity of compounds (organic acid/proteins/H2O2) produced by the bacterium revealed that organic acids were responsible for this activity. As observed by scanning electron microscopy (SEM), shrunken hyphae and pores on the cell surface were observed in cell free supernatant (CFS)-treated fungi. The predominant organic acids identified in the CFS were lactic acid and acetic acid, respectively. Furthermore, the genome of W. cibaria KM14 contained a significant number of genes (130) that were responsible for organic acid biosynthesis. Based on these data, it has been speculated that W. cibaria KM14-CFS inhibits fungal growth via two potential mechanisms: decreasing hyphal surface decoration and damaging the mycelia.

Circular economy reinforcement through molecular fabrication of textile wastes with microbial synthesized ZnO nanoparticles to have multifunctional properties

The fibrous wastes generated from the mills of textile production can be recycled and converted into high add-values products to be implemented in several applications. The current study aimed to employ commercial free cellulase enzyme to partially hydrolyze (activate) the polyester cotton blended (PET/C) fibrous wastes by creation functional groups such as OH and COOH on their surfaces. The activated fibrous wastes were then modified by coating with ZnO nanoparticles (ZnO-NPs) biosynthesized by actinobacterial cultures free supernatant. The isolate was identified as Streptomyces pseudogriseolus with accession number of OR574241. The conditions that influence the actino-synthesis of ZnO-NPs were optimized and the product was characterized using spectroscopic vision, FTIR, XRD, TEM and SEM. The characteristic ZnO peaks were obviously observed by EDX analysis with 0.38 and 0.75% (wt%), respectively. TEM analyses proved the nanoscale of ZnO-NPs (5–15 nm) which was followed by cytotoxic evaluation for the produced NPs. Fortunately, the tested actino-ZnO-NPs didn’t have any cytotoxicity against human normal fibroblast cell line (BJ1), which means that the product can be safely used in a direct-contact with human skin. The treated PET/C blended waste fabrics coated with ZnO-NPs showed high antimicrobial activity and ultraviolet protection values after functionalization by cellulase. EDX analysis demonstrates the presence of Zn peaks on the coated fabrics compared with their absence in blank and control samples, while SEM images showed the formation of a thin layer of ZnO-NPs on the fabric surface. The obtained smart textile can be applied several needed sectors.

Biochemical characterisation and production kinetics of high molecular-weight (HMW) putative antibacterial proteins of insect pathogenic Brevibacillus laterosporus isolates

BackgroundBacterial genomes often encode structures similar to phage capsids (encapsulins) and phage tails which can be induced spontaneously or using genotoxic compounds such as mitomycin C. These high molecular-weight (HMW) putative antibacterial proteins (ABPs) are used against the competitive strains under natural environment. Previously, it was unknown whether these HMW putative ABPs originating from the insect pathogenic Gram-positive, spore-forming bacterium Brevibacillus laterosporus (Bl) isolates (1821L, 1951) are spontaneously induced during the growth and pose a detrimental effect on their own survival. Furthermore, no prior work has been undertaken to determine their biochemical characteristics.ResultsUsing a soft agar overlay method with polyethylene glycol precipitation, a narrow spectrum of bioactivity was found from the precipitated lysate of Bl 1951. Electron micrographs of mitomycin C- induced filtrates showed structures similar to phage capsids and contractile tails. Bioactivity assays of cell free supernatants (CFS) extracted during the growth of Bl 1821L and Bl 1951 suggested spontaneous induction of these HMW putative ABPs with an autocidal activity. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis of spontaneously induced putative ABPs showed appearance of ~ 30 kDa and ~ 48 kDa bands of varying intensity across all the time intervals during the bacterial growth except in the initial hours. Statistically, spontaneously induced HMW putative ABPs of Bl 1951 exhibited a significant decrease in the number of viable cells of its producer strain after 18 h of growth in liquid. In addition, a significant change in pH and prominent bioactivity of the CFS of this particular time period was noted. Biochemically, the filtered supernatant derived from either Bl 1821L or Bl 1951 maintained bioactivity over a wide range of pH and temperature.ConclusionThis study reports the spontaneous induction of HMW putative ABPs (bacteriocins) of Bl 1821L and Bl 1951 isolates during the course of growth with potential autocidal activity which is critically important during production as a potential biopesticide. A narrow spectrum of putative antibacterial activity of Bl 1951 precipitate was found. The stability of HMW putative ABPs of Bl 1821L and Bl 1951 over a wide range of pH and temperature can be useful in expanding the potential of this useful bacterium beyond the insecticidal value.

Investigation of heat-resistant antifungal agents from Bacillus amyloliquefaciens and Bacillus subtilis for biocontrol of mycotoxigenic fungi

Fungal infections of food and feed with toxigenic strains results in the accumulation of harmful metabolites. In this study, the antifungal activity of two indigenous bacterial strains Bacillus amyloliquefaciens and Bacillus subtilis isolated from camel feed was investigated. The potential of the bacterial cell free supernatant (CFS) to reduce mycotoxins synthesis was evaluated, and the impact of their antifungal metabolites on the fungal hyphae was examined. High antagonistic activity was exhibited by both bacterial strains. The best activity was observed against two mycotoxigenic A. niger strains (Sp31 and Sp33) with inhibition zones of 36.75 ± 0.7 mm and 35.75 ±1.5 mm, by strains B. amyloliquefaciens and B. subtilis, respectively. The effects of these bacterial strains’ CFSs on mycotoxins synthesis were investigated, and both CFSs were found to reduce the mycotoxins synthesis by A. parasiticus, A. niger and Penicillium spp., in a dose-dependent manner. Moreover, the fungal cell wall morphology was significantly altered by the bacterial CFS at a very low concentration of 1 %. The heat stability of the antifungal metabolites was evaluated at various temperatures ranging from −20 °C to 100 °C, and the metabolites were found to be highly stable, retaining their antifungal activity against A. niger. The antifungal activity of B. amyloliquefaciens and B. subtilis was stable at −20 °C for 236 and 34 days of storage, respectively. These findings suggest that both bacterial strains are exceptional candidates in the biocontrol of mycotoxigenic fungi and in the reduction of their toxic metabolites.

The combined effect of Weisella cibaria and Fusarium oxysporum nanoparticles on cervical cancer cells

من المتوقع أن يتجاوز عبء السرطان العالمي المتوقع 20 مليون حالة سرطان جديدة بحلول عام 2025. على الرغم من التقدم الأخير في علاج الأورام ، لا يزال علاج السرطان الناجح يمثل تحديًا. يوفر مجال تكنولوجيا النانو الناشئ فرصًا رائعة لتشخيص السرطان ، والتصوير ، وعلاج السرطان. يعتبر التخليق الحيوي لجسيمات الفضة النانوية عن طريق الفطريات طريقة نظيفة وغير سامة بيئيًا مقارنة بالطرق الفيزيائية والكيميائية الأخرىالغرض من هذه الدراسة هو تحديد التأثير التآزري للجسيمات النانوية المركبة من Fusarium oxysporum مع Weisella cibaria ضد خلايا سرطان عنق الرحمأجريت هذه الدراسة من عام 2022 إلى مارس 2023 في معمل ميكروبيولوجيا الغذاء في قسم الأحياء / كلية العلوم / الجامعة المستنصرية. تم عزل بكتيريا حمض اللاكتيك (LAB) من مصادر الغذاء (الشلغم ، اللهانه ، الشوندر والقرنابيط) ، بعد خطوات متسلسلة من كلوريد الصوديوم المعالج ، ثم تم تربيتها في مرق MRS (Man-Rogosa-Sharpe) ، وتم فحصها تحت المجهر. تم الكشف عن النشاط المضاد للبكتيريا في المواد الطافية الخالية من الخلايا (CFS) التي تنتجها هذه العزلات لاختيار الأفضل وتشخيصها عن طريق تسلسل تفاعل البوليميراز المتسلسل والحمض النووي. تم الحصول على الجسيمات النانوية (AgNo3) التي تم إنتاجها من Fusarium oxysporum بالتخليق الحيوي من مختبر الدراسات العليا للفطريات ، وتم إخضاع هذه الفطريات لاختبار السمية. تمت دراسة تأثير التآزر للجسيمات النانوية المختارة من LAB و Fusarium oxysporum ضد خلايا سرطان عنق الرحم. أظهرت هذه الدراسة أن جميع مصادر الغذاء كانت غنية بـ LAB وأن أفضل نشاط مضاد للجراثيم كان مصدر اللفت ووفقًا للتشخيص الجزيئي كان Weisella cibaria والذي سجل في NCBI كـ (MG7865551). أظهر التأثير التآزري لـ Weisella cibaria والجسيمات النانوية انخفاض معدل بقاء خط السرطان بعد 72 ساعة من التعرض لهذا التأثير.

Assessment of the probiotic, anti-bacterial, and anti-biofilm characteristics of Lacticaseibacillus rhamnosus CWKu-12, along with its potential impact on the expression of virulence genes in Listeria monocytogenes ATCC 19115

The purpose of this study was to investigate the potential probiotic properties, gene expression related to biofilm formation, and anti-biofilm capabilities of Lacticaseibacillus rhamnosus CWKu-12. This strain showed notable resistance to acidic conditions, gastrointestinal environments, and bile salts. Additionally, L. rhamnosus displayed significant levels of auto-aggregation (36.60%), hydrophobicity (52.60%), co-aggregation (29.10%), free radical scavenging activities (55–59%), and cholesterol reduction (49.30%). Its ability to compete with, replace, and hinder the adhesion of Listeria monocytogenes was measured at 41.70%, 22.60%, and 30.54% respectively. L. rhamnosus also showed an adhesion rate of 11.80% to epithelial cells, did not exhibit DNase or hemolytic activity. It was susceptible to the antibiotics ciprofloxacin, erythromycin, and chloramphenicol and semi-susceptible to ampicillin, imipenem, nitrofurantoin, and nalidixic acid. The strain's cell free supernatant (CFS) effectively inhibited and eliminated L. monocytogenes biofilm formation, with inhibitory rates of 44.30% and eradication rate of 38.70%. Treatment with CFS also led to a significant decrease in the expression of various genes related to L. monocytogenes by percentages ranging from 35.54% to 79.80%. Overall, these findings support the potential of L. rhamnosus CWKu-12 as a probiotic, with its ability to survive in the digestive system, and combat harmful bacteria making it a promising candidate.