Bacteria Bacillus Cereus Research Articles

Characterization of alkaline metalloprotease isolated from halophilic bacterium Bacillus cereus and its applications in various industrial processes.

Microbial proteases are one of the most demanding enzymes for various industries with diverse applications in food, pharmaceutics, and textile industries to name the few. An extracellular alkaline metalloprotease was produced and purified from moderate halophilic bacterial strain, Bacillus cereus TS2, with some unique characteristics required for various industrial applications. The protease was produced in basal medium supplemented with casein and was partially purified by ion exchange chromatography followed by ammonium sulphate precipitation. The alkaline metalloprotease has molecular weight of 35 kDa with specific activity of 535.4 µM/min/mg. It can work at wide range of pH from 3 to 12, while showing optimum activity at pH 10. Similarly, the alkaline metalloprotease is stable till the temperature of 80 °C and works at wide range of temperature from 20 to 90 °C with optimum activity at 60 °C. The turnover rate increases in the presence of NaCl and Co+2 with k cat/KM of 1.42 × 103 and 1.27 × 103 s-1.M-1 respectively, while without NaCl and Co+2 it has a value of 7.58× 102. The alkaline metalloprotease was relatively resistant to thermal and solvent mediated denaturation. Applications revealed that the metalloprotease was efficient to remove hair from goat skin, remove blood stains and degrade milk, thus can be a potential candidate for leather, detergent, and food industry.

Invasive Ageratina adenophora can maintain its ecological advantages over time through releasing its autotoxicity by accumulating a bacterium Bacillus cereus

Plant invasive success is attributed to invaders’ ecological advantages over their native neighbors. However, increasing evidence suggests that these advantages are expected to attenuate over time because of natural enemy accumulation, ecological evolution of native species and autotoxicity. We determined how an invasive Ageratina adenophora could remain its competitive advantages over time by avoiding its autotoxicity. Our results highlighted that the autotoxicity of A. adenophora in its invaded soil was reduced by some microbes. Moreover, an autotoxic allelochemical, 2-coumaric acid glucoside, detected in the invaded soil, demonstrated distinctly autotoxic effects on its seed germination and seedling growth. However, the autotoxic effects were greatly alleviated by a bacterium Bacillus cereus, accumulated by A. adenophora. Furthermore, the allelochemical could be almost completely degraded by B. cereus within 96 h. Accordingly, we speculate that A. adenophora could aggregate B. cereus to release its autotoxicity maintaining its competitive advantages over time.

Determination of the Rate Constant of Microorganisms Destruction after Ultrasound Water Treatment and Different Gases Action

The change of microorganisms number (rod-like spore-containing Bacillus cereus bacteria type) for the range of 102 ÷ 106 CFU in 1 cm3 from the duration of simultaneous action of ultrasound (US) cavitation and the nature of different gas (carbon dioxide, oxygen, argon) is presented. The graphical dependences of the effective rate constant values of microorganisms destruction (kd) on its initial number per unit volume of water at different modes of its treatment are shown. The destruction degrees of bacterial cells in the process of water purification are calculated. It was investigated that the value of kd does not depend on the initial number of cells in water, but depends on the nature of the bubbled gas through the reaction aqueous medium: kd(Ar/US) > kd(O2/US) > kd(CO2/US).

Dual inoculation with rhizosphere-promoting bacterium Bacillus cereus and beneficial fungus Peniophora cinerea improves salt stress tolerance and productivity in willow

Utilization of rhizosphere microorganisms to improve plant growth and salt tolerance has recently attracted widespread attention. The growth and salt tolerance of willows inoculated with Bacillus cereus JYZ-SD2 and Peniophora cinerea XC were studied under different salt stress conditions. The results showed that the chlorophyll content of willow cuttings inoculated with the XC strain increased significantly by 51.27%. After salt stress of willow cuttings inoculated with B. cereus JYZ-SD2 and P. cinerea XC (solely or in combination), the amount of sodium in the roots from the epidermis to the pericycle decreased and the content of sodium in the pericycle was significantly lower than that of the uninoculated willow, while the proportion of potassium increased. Willow cuttings inoculated with microorganisms showed increased activity of SOD and POD. At the salt concentration of 100 mmol/L, the highest SOD activity was found in B. cereus JYZ-SD2-inoculated willows, with 59.88% increase compared to uninoculated willows; the highest POD activity was found in P. cinerea XC and B. cereus JYZ-SD2 co-inoculated willows, with 51.05% increase compared to uninoculated willows. The Na-K-ATPase and Ca-Mg-ATPase activities of inoculated P. cinerea XC willow cuttings were also 59.38% and 60% higher than that of uninoculated willows, respectively. The qPCR analysis showed that the expression of vp2 gene in the microorganism-inoculated willow leaves was always higher than that in willow alone. The expression of vp2 gene in P. cinerea XC-inoculated willow cuttings was 270.81% higher than that in uninoculated willows. Further observation of the ultrastructure of root cells under salt stress revealed that most of the vesicles in the root tip cells of willow were intact and secreted phagocytic vesicles to absorb sodium ions in the cytoplasm. This study shows that the combined beneficial fungi and rhizosphere-promoting bacteria inoculation technology as a practical biotechnological approach to enhance the growth of willows in salt-affected soils.

Antimicrobial effect of cotton fabric functionalized with a kaolinite-titania nano-hybrid composite

It is well known that certain diseases can be transmitted through contact with contaminated surfaces. Due to the structural characteristics and composition, textile products are favorable media for the retention, growth, and propagation of pathogens, making them potential vehicles for contamination. The current health and humanitarian crises have highlighted the urgent task of exploring effective antimicrobial agents that help prevent and combat emerging microbiological diseases. Based on this, the present work investigated the antimicrobial activity of a cotton fabric functionalized with kaolinite-titania nano-hybrid particles. The antimicrobial activity was evaluated against Escherichia coli (Gram-negative) and Bacillus cereus (Gram-positive) bacteria. Results show that the composite can enhance the photoactivity of the immobilized TiO2, inducing the complete disinfection of the medium in contact with the treated fabric.

Improvement of the Dyeability and Salt-Free Dyeing for Wool Fabrics with Anionic Dyes by Pretreatment with Whey and Soybean Proteins

ABSTRACT Wool fabrics were pretreated with whey protein concentrate (WPC) and soybean flour (SPF) proteins individually to improve their dyeability toward anionic dyes as acid orange 10 (AO10) and reactive black 5(RB5). Comprehensive study was undergone on these fabrics evaluating their dyeability, functional properties and the possibility to reduce the need for electrolyte in the dyebath. Furthermore, coating with protein as a biopolymer is more environmentally friendly. The structure and properties of the pretreated wool fabric were evaluated by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), ultraviolet spectroscopy (UV) and antimicrobial activity. Nitrogen content was used to confirm the existence of amino groups on treated protein fabrics compared to the untreated one. All the pretreated dyed samples were enhanced in color strength (K/S). The color strength of wool treated fabrics without salt was the highest. Treating fabrics indicated better protection against ultraviolet radiation and the highest UV protection factor (UPF) was of white and dyed wool fabrics treated with SPF. The highest antimicrobial activity reduction percent against gram positive bacteria (Bacillus cereus) was in the sample treated with WPC as well as the sample treated with SPF has the greatest antimicrobial activity effect against fungal yeast (Candida albicans).

Bioactive gliadin electrospinning loaded with Zataria multiflora Boiss essential oil: Improves antimicrobial activity and release modeling behavior.

This study aimed to produce electrospun gliadin nanofibers containing Zataria multiflora Boiss essential oil (ZMEO) (5, 10, and 15% w/w), thereby developing active, sustained-release antimicrobial mats. By increasing the level of the ZMEO, the zeta potential and electrical conductivity increased, but the viscosity and consistency index decreased. All feed solutions demonstrated shear-thinning behavior, and the power law model was the best model. Field emission scanning electron microscopy (FESEM) images proved that the gliadin nanofibers showed a uniform, beaded-free structure at different levels of ZMEO, with an average diameter of between 403.87 ± 15.29 and 522.19 ± 11.23 nm. Increments in the level of ZMEO decreased the mats' tensile strength and Young's modulus but increased their elongation at break. Fourier transform infrared (FTIR) and differential scanning calorimetry (DSC) analysis confirmed that the ZMEO was well loaded within these structures, augmenting its thermal stability. The studied Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) were more resistant to the ZMEO than the Gram-positive bacteria (Bacillus cereus and Staphylococcus aureus). The Peleg model was the most suitable model for describing the ZMEO release behavior, the mechanism of which was primarily Fickian diffusion.

Evaluation of The Spirulina (Arthrospira platensis Gomont) Antimicrobial Activity

The present work was carried out to enhance biomass production of Spirulina (Arthrospira platensis Gomont) in a modified medium and to investigate “in vitro” its ability to produce antimicrobial substances against pathogenic bacteria and phytopathogenic fungi. The antibacterial activity was evaluated by the solid medium diffusion method on two pathogenic bacteria (Bacillus cereus & Klebsiella sp.), And the antifungal activity was evaluated on three phytopathogenic fungi (Alternaria solani, Cladosporium sp., Fusarium culmorum). The antibacterial test showed that the aqueous extract produced by S. platensis was more active against Gram-positive than on Gram-negative bacteria, the highest antibacterial activity was recorded against Bacillus cereus. Moreover, the Antifungal test showed that the aqueous extract was active against all three tested fungi and the highest antifungal activity was recorded against F. culmorum with over 90% inhibition of mycelial growth. The results of this research proved that cyanobacteria could be a good source for the production of antimicrobial agents which could be effective when compared with contemporary antimicrobial compounds and it can be used in the Biocontrol of several plant fungal diseases.

Short Communication: Antimicrobial of lemongrass (Cymbopogon citratus L.) volatile oil and cytotoxic effects against L20B and MCF-7cell lines

Abstract. Hasan ZYM, Al-Halbosiy MMF, Al-Lihaibi RK, Al-Nauimi EH. 2022. Short Communication: Antimicrobial of lemongrass (Cymbopogon citratus L.) volatile oil and cytotoxic effects against L20B and MCF-7cell lines. Biodiversitas 23: 5298-5301. Lemongrass (Cymbopogon citratus L.) has been used in different countries in folk remedies for coughs, malaria, pneumonia, and others for many years. The development of bacterial resistance to available antibiotics has obligated finding for new agents to serve as potent antibacterial drugs. The present investigation deals with the effect of volatile lemongrass oil cultivated in Iraq, on different bacterial species and evaluates the cytotoxic activity of the extracted oil on L20B and MCF-7cell cancer cell lines. The plant samples were collected from the college of science /Baghdad University /scientific garden and classified as C. citratus L. by the plant herbarium at the same college. The volatile plant oil was extracted from fresh leaves at the laboratory of the plant biotechnology department of Biotechnology Research Center at Al-Nahrain university/Iraq. With the aid of the Clevenger apparatus, a hydro-distillation method was employed to quantify the lemon grass’s volatile oil. The extracted essential oil and the plant crud maceration were screened for their antibacterial activity against two Gram-negative bacteria (Escherichia coli, and Vibrio cholera) and two Gram-positive bacteria (Bacillus cereus and Staphylococcus aureus) using the well-diffusion method and disc diffusion method. The biological survey also included the cytotoxic effect of oil subjected to the anticancer activity in vitro on two cancer cell lines; L20B mouse cell line that expresses the genes for human cellular receptors for polioviruses, and the second line was the MCF-7 breast cancer cell line. As a result of this screening study, it was shown that the plant seemed to be rich in essential oil content. The Iraqi cultivated plant produced 1.5%v/w essential oil. The volatile oil affected both Gram-negative and Gram-positive strains in comparison to the crud plant extract among the selected bacterial cultures, the highest antibacterial activity was recorded against the Gram-positive strain S. aureus by well diffusion method. Besides, the plant oil showed an inhibitory effect on L20B cell line with a percent inhibitory growth rate reaching 47.1% at 1.125 ?l/mL of the oil concentration. While for the other cell line, MCF-7 cell line, the inhibitory growth rate percentage appeared for almost all concentrations in comparison with control after 24 hours, and even at a concentration of 0.3125?l/mL, the inhibitory growth rate percentage reached up to 86%. This study was conducted to high lightened the benefits of this plant as little study had been done for an Iraqi cultivated plant and the results showed the potent biological effects of the plant especially the volatile oil as an antimicrobial and as a potent cancer inhibitory agent.

Pseudomonas sp., Strain L5B5: A Genomic and Transcriptomic Insight into an Airborne Mine Bacterium

Mines, like other subterranean environments, have ecological conditions which allow the thriving of microorganisms. Prokaryotes and fungi are common inhabitants of mines, developing a metabolism suitable for growing in such inhospitable environments. The mine of Lousal, Portugal, is an interesting site for the study of microorganisms present in their galleries. Aerobiological studies resulted in the isolation of a Pseudomonas sp., strain L5B5, closely related to the opportunistic fish pathogen P. piscis MC042T, and to the soil bacteria P. protegens CHA0T, P. protegens Cab57, and P. protegens Pf-5. Strain L5B5 was able to inhibit the growth of the pathogenic bacteria Bacillus cereus, Staphylococcus aureus, and Acinetobacter baumanii, as well as the cave fungi Aspergillus versicolor, Penicillium chrysogenum, Cladosporium cladosporioides, Fusarium solani, and Ochroconis lascauxensis. In silico analyses based on de novo genome hybrid assembly and RNA-Seq, performing seven conditions based on culture and phases of growth resulted in the prediction and detection of genetic mechanisms involved in secondary metabolites, with the presence of a possible new gene cluster transcribed under the tested conditions, as well as feasible virulence factors and antimicrobial resistance mechanisms.

Squaric acid driven supramolecular metallogels of Cd(II) and Zn(II): Sensitive inhibitors for multi-drug resistance ESKAPE pathogens

The article depicts the synthesis and significance of two metallogels of squaric acid implementing Cd(II) and Zn(II)-metal salts. N,N΄-dimethyl formamide has been utilised as an immobilised solvent for successive construction of metal ions directed both gel scaffolds. These metallogels exhibit an intriguing visco-elasticity which gets experimentally validated by rheological findings. Microstructural versatility with varied metal ions and EDS elemental analysis confirm the presence of all the gel-forming constituents present in the observed hierarchical morphological visualizations for both soft-scaffolds. FT-IR data indicate the considerable shifting of peaks compared to precursor gel-forming ingredients and also establish that the metallogel-development tactic might be progressed by non-covalent type supramolecular interactions. Comparative analysis of these metallogels as anti-bacterial agents against multi-drug resistive deadly pathogens including Gram-negative bacteria Escherichia coli, Salmonella typhimurium, Vibrio parahaemolyticus and Gram-positive bacteria Bacillus cereus, and Staphylococcus aureus reveals them as the potential and promising bio-functional stuffs. Thus, the bactericidal effects of Cd(II) and Zn(II) based squaric acid mediated metallogels against ESKAPE pathogens are accounted in this study.

Click-Chemistry-Mediated Synthesis of Silver Nanoparticle-Supported Polymer-Wrapped Carbon Nanotubes: Glucose Sensor and Antibacterial Material.

We report a novel approach for the synthesis of silver nanoparticles (NPs) stabilized on polymer-wrapped carbon nanotubes (Ag@polymer/CNTs) for the non-enzymatic glucose sensing and antibacterial activity applications. Poly(styrene-alt-maleic anhydride) (PSM) was functionalized with amino furan to obtain furan-modified poly(styrene-alt-maleic anhydride) (PSMF), which was later grafted onto the surface of CNTs by Diels–Alder “click” reaction to afford a polymer/CNTs hybrid material. The photo-deposition technique was applied to immobilized small-sized (∼10 nm) AgNPs on the surface of the polymer/CNTs hybrid material using visible light irradiation. The resulting material, Ag@polymer/CNTs, showed promising electrocatalytic activity for the non-enzymatic glucose sensing and antibacterial activity in vitro assays toward Escherichia coli, Staphylococcus aureus, and Bacillus cereus bacteria strains. Covalent-bonded polymer layer-bearing carboxylic pendent groups to the CNTs might be playing a pivot role in not only stabilizing AgNPs but also facile electron-transfer reaction, thus demonstrating better activity.

Genomic versus Plasmid-Borne Expression of Germinant Receptor Proteins in Bacillus cereus Strain 14579

Germinant receptors (GRs) are proteins in the spore-forming bacteria of Bacillus species that are crucial in triggering spore germination by sensing nutrients in the spores’ environment. In the Gram-positive bacterium Bacillus cereus strain ATCC 14579, the GerR GR initiates germination with L-alanine. While we have expressed GerR subunits fused to reporter proteins from genes under control of their native promoter on plasmids in this B. cereus strain, here we sought increased flexibility in this work by studying genome integration and plasmid-borne inducible high level (over) expression. However, construction of chromosomal integrants to visualize and localize the GerR B subunit fused to fluorescent reporter protein SGFP2 was not successful in this B. cereus strain using constructs with either shorter (~600 bp) or longer (~1200 bp) regions of homology to the gerR operon. This failure was in contrast to successful IPTG-inducible expression of GerRB-SGFP2 from plasmid pDG148 in vegetative cells and dormant spores, as fluorescent GerRB-SGFP2 foci were present in vegetative cells and the protein was detected by Western blot analysis. In dormant spores, the fluorescence intensity with IPTG-inducible expression from pDG148-gerRB-SGFP2 was significantly higher than in wild type spores. However, the full length GerRB-SGFP2 protein was not detected in spores using Western blots. Clearly, there are still challenges in the construction of B. cereus strains harboring fluorescent reporter proteins in which tagged proteins are encoded by genes incorporated in the chromosome or on extrachromosomal expression plasmids.

Identification of Sulphur Oxidizing Bacteria on Charcoal Made of Salak Fruit Seeds for Hydrogen Sulfide Removal in Biogas

Alternative energy sources to substitute fossil fuels have been developed, biogas being one of them. However, H2S needs to be removed in biogas because it promotes corrosion in the equipment using biogas. The H2S can be removed from biogas by biological processes. H2S was removed by biofiltration, in which H2S degrading bacteria immobilized on the packing material inside a column. This study aimed to determine the genera of microorganisms that degrade H2S in biogas. Moreover, this research aimed to investigate the ability of these microorganisms to degrade H2S. The novelty of this research is the use of charcoal from salak fruit seed as a packing material for immobilization the microorganisms in the biofilter; therefore, the packing material is more durable and does not rot. The isolated sludge taken from liquid wastewater treatment in the tofu industry was tested for sulfide degradation. Then, the best of bacteria to degrade sulfide was immobilized on the surface of charcoal made of salak fruit seeds and after acclimatization and the bacteria grew well. We tested their capability of forming biofilms on the surface of the charcoal of salak fruit seeds. Further identification showed that the isolate was Bacillus cereus with a similarity value of 98%. An experiment to remove H2S of biogas using a biofilter column with immobilized Bacillus cereus bacteria on the surface of the charcoal of salak fruit seeds showed that the Bacillus cereus bacteria could degrade H2S of biogas that flew in the biofilter through the surface of charcoal of salak fruit seeds. The highest removal efficiency was obtained for H2S (RE) at the packing height of 80 cm; 97.15% of which was achieved at a biogas flow rate of 30 L/hour, the H2S concentration was 142.48 ppm for 4 hours.

Biological control of M. javanica in tomato and induction of host resistance using Bacillus cereus in vitro, green house and field

Use of biological control agents for managing phytoparasitic nematodes is a good choice for the development of safe and sustainable agricultural production. In this study a bacterium Bacillus cereus was evaluated as biocontrol agent against Meloidogyne javanica in tomato crop. The potential of B. cereus for the mortality of M. javanica J2s and egg hatch inhibition was tested in vitro. Transgenic strains (GFP-tagged B. cereus) of the biological control bacteria was developed and used for the analysis of tomato root colonization and confirmed through qPCR analysis. The host resistance induced by biocontrol agent was evaluated through split pot experiment and analysis of defense related genes. Finally, the efficiency of biocontrol agent to manage the M. javanica in tomato crop was investigated through pot and field experiment. Results showed that B. cereus can cause significant J2s mortality, egg hatch inhibition of M. javanica and successfully colonized the tomato roots. Through qPCR it was confirmed that the concentration of biocontrol agent in tomato roots increased with time. Results regarding split root experiment and analysis of host resistance related genes of tomato plant indicated that B. cereus effectively induced host resistance showing upregulation of resistance related genes. In green house and field trail, application of B. cereus resulted in significant decrease in egg masses and gall numbers on roots of tomato plants and increased yield and plant growth. The B. cearus was also investigated for the presence of emetic toxins and enterotoxin genes and none of the studied toxin genes have been detected. This study suggested that B. cereus can effectively control M. javanica in tomato and possibly other crops.

Antibacterial and in vivo toxicological studies of Bi2O3/CuO/GO nanocomposite synthesized via cost effective methods

In this research work, Bi2O3, Bi2O3/GO and Bi2O3/CuO/GO nanocomposites have been synthesized via an eco-friendly green synthesis technique, solgel route and co-precipitation method respectively for the assessment of antibacterial activity as well as in vivo toxicity. The XRD patterns confirm the formation of Bi2O3, Bi2O3/GO and Bi2O3/CuO/GO nanocomposites showing monoclinic structures. Crystallite size and lattice strain are calculated by Scherrer equation, Scherrer plot and Willimson Hall plot methods. Average crystallite size measured for Bi2O3, Bi2O3/GO and Bi2O3/CuO/GO nanocomposites by Scherrer equation, Scherrer plot and WH-plot methods are (5.1, 13.9, 11.5)nm, (5.4, 14.2, 11.3)nm and (5.2, 13.5, 12.0)nm respectively. Optical properties such as absorption peaks and band-gap energies are studied by UV–vis spectroscopy. The FTIR peaks at 513 cm−1, 553 cm−1 and 855 cm−1 confirms the successful synthesis of Bi2O3, Bi2O3/GO and Bi2O3/CuO/GO nanocomposites. The antibacterial activity of synthesized Bi2O3, Bi2O3/GO and Bi2O3/CuO/GO nanocomposites is examined against two gram-negative (Escherichia coli and pseudomonas) as well as gram-positive bacteria (Bacillus cereus and Staphylococcus aureus) at dose 25 mg/kg and 40 mg/kg by disk diffusion technique. Zone of inhibition for Bi2O3, Bi2O3/GO and Bi2O3/CuO/GO at dose 40 mg/kg against E. coli (gram − ve) are 12 mm, 17 mm and 18 mm respectively and against Pseudomonas (gram − ve) are 28 mm, 19 mm and 21 mm respectively. While the zone of inhibition for Bi2O3/GO and Bi2O3/CuO/GO at dose 40 mg/kg against B. cereus (gram + ve) are 8 mm and 8.5 mm respectively and against S. aureus (gram + ve) are 5 mm and 10.5 mm respectively. These amazing results reveal that Bi2O3, Bi2O3/GO and Bi2O3/CuO/GO nanocomposite as a kind of antibacterial content, have enormous potential for biomedical applications. In addition, the in vivo toxicity of synthesized Bi2O3/CuO/GO nanocomposite is investigated on Swiss Albino mice at dose of 20 mg/kg by evaluating immune response, hematology and biochemistry at the time period of 2, 7, 14 and 30 days. No severe damage is observed in mice during whole treatment. The p value calculated by statistical analysis of hematological and biochemistry tests is nonsignificant which ensures that synthesized nanocomposites are safe and non-toxic as they do not affect mice significantly. This study proves that Bi2O3/CuO/GO nanocomposites are biocompatible and can be explored further for different biomedical applications.

Synthesis of Silver Nanocomposite Based on Carboxymethyl Cellulose: Antibacterial, Antifungal and Anticancer Activities.

Traditional cancer treatments include surgery, radiation, and chemotherapy. According to medical sources, chemotherapy is still the primary method for curing or treating cancer today and has been a major contributor to the recent decline in cancer mortality. Nanocomposites based on polymers and metal nanoparticles have recently received the attention of researchers. In the current study, a nanocomposite was fabricated based on carboxymethyl cellulose and silver nanoparticles (CMC-AgNPs) and their antibacterial, antifungal, and anticancer activities were evaluated. The antibacterial results revealed that CMC-AgNPs have promising antibacterial activity against Gram-negative (Klebsiella oxytoca and Escherichia coli) and Gram-positive bacteria (Bacillus cereus and Staphylococcus aureus). Moreover, CMC-AgNPs exhibited antifungal activity against filamentous fungi such as Aspergillus fumigatus, A. niger, and A. terreus. Concerning the HepG2 hepatocellular cancer cell line, the lowest IC50 values (7.9 ± 0.41 µg/mL) were recorded for CMC-AgNPs, suggesting a strong cytotoxic effect on liver cancer cells. As a result, our findings suggest that the antitumor effect of these CMC-Ag nanoparticles is due to the induction of apoptosis and necrosis in hepatic cancer cells via increased caspase-8 and -9 activities and diminished levels of VEGFR-2. In conclusion, CMC-AgNPs exhibited antibacterial, antifungal, and anticancer activities, which can be used in the pharmaceutical and medical fields.

Synthesis, characterization and evaluation of antimicrobial potential of zinc(II) complexes of nitro-substituted hydroxamic acid chelators

The nitro-substituted hydroxamic acid chelators potassium 4-nitrobenzohydroxamate (4-(NO2)C6H4CONHOK) (KHL1) and 3,5-dinitrosalicylhydroxamate (3,5-(NO2)2(OH)C6H2CONHOK) (KHL2) on reaction with anhydrous zinc(II) chloride (ZnCl2) in 1:2 metal:ligand ratio in MeOH + THF afforded new zinc(II) complexes, [Zn(4-(NO2)C6H4CONHO)2] (1) and [Zn(3,5-(NO2)2(OH)C6H2CONHO)2] (2). The structural characterization of 1 and 2 has been accomplished by physicochemical studies; elemental analyses, molar conductivity, cyclic voltammetry and spectroscopic techniques in the solid state (IR) and in solution (1H NMR and UV-visible). The stoichiometric composition of 1 and 2 has been authenticated by mole ratio method and the stability constants were determined. IR spectral studies suggested the bidentate nature of ligands involving bonding through carbonyl and hydroxamic oxygen atoms (O,O’-coordination). The mass spectral data of 1 and 2 have indicated these to be mononuclear. In order to infer the biological relevance of newly synthesized complexes, the in vitro antimicrobial activity assay against pathogenic gram-ve bacteria, viz. Salmonella typhi and Escherichia coli; gram + ve bacteria Bacillus cereus and Staphylococcus aureus and fungi Rhizoctoniasolani and Fusarium sambucinum by MIC method has shown appreciable antimicrobial potential. The results have been compared with standard Tetracycline and Nystatin drugs.

Characterization of the biosynthesized intracellular and extracellular plasmonic silver nanoparticles using Bacillus cereus and their catalytic reduction of methylene blue

The biosynthesis of silver nanoparticles (Ag NPs) has been studied in detail using two different approaches. For the first time, Bacillus cereus is used for one-pot biosynthesis of capsulated Ag NPs, using both intracellular and extracellular approaches. To discriminate between the produced nanostructures by these two approaches, their structures, nanomorphologies, optical properties, hydrodynamic sizes and zeta potentials are studied using different techniques. Fourier-transform infrared spectroscopy was used to identify the bioactive components responsible for the reduction of Ag+ ions into Ag and the growth of stable Ag NPs. Scanning and transmission electron microscopy images displayed spherical and polygon nanomorphology for the intracellular and extracellular biosynthesized Ag NPs. For intracellular and extracellular biosynthesized Ag NPs, a face-centred cubic structure was observed, with average crystallite sizes of 45.4 and 90.8 nm, respectively. In comparison to the noncatalytic reduction test, the catalytic activities of intracellular and extracellular biosynthesized Ag NPs were explored for the reduction of highly concentrated MB dye solution. Extracellular Ag NPs achieved 100% MB reduction efficacy after around 80 min, compared to 50.6% and 24.1% in the presence and absence of intracellular Ag NPs, respectively. The rate of MB reduction was boosted by 22 times with the extracellular catalyst, and by 3 times with the intracellular catalyst. Therefore, the extracellular production process of Ag NPs utilizing Bacillus cereus bacteria might be applied in the industry as a cost-effective way for eliminating the toxic MB dye.

The Antagonistic and Synergistic Comparison of the Antimicrobial Characteristics of Extracts of Some Herbs

In the present study, the antagonistic and synergistic effects of Achillea millefolium L., Anthemis cretica L., Cichorium intybus L., Euphorbia seguieriana Necker and Hypericum perforatum L plant extracts collected from Samsun were investigated. Gram negative bacteria; Escherichia coli, Acinetobacter baumannii, Salmonella typhimurium, Gram positive bacteria; Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes were used as research materials. In the research, methanol and diethyl were used as solvents. The antibacterial activities of the extracts were determined by microbroth dilution method. According to the results of the research; all plant extracts obtained using both methanol and diethyl ether solvent were determined to be more effective against gram positive bacteria. While the whole plant extract showed the most effect on Bacillus cereus bacteria, Hypericum perforatum L. methanol extract was the most effective plant against gram positive bacteria. Achillea millefolium L.: Cichorium intybus L., Achillea millefolium L.: Hypericum perforatum L. and Cichorium intybus L.: Hypericum perforatum L. methanol mixture extracts and Achillea millefolium L.: Hypericum perfarotum L. diethyl ether extract showed a synergistic effect, while other plant mixture extracts showed semi-synergistic or ineffective properties.