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Modification of paint with nanoparticles (NPs) provides self-cleaning, water/dirt-repellent, and other properties. Therefore, the aim of the present study was to biosynthesize silver (Ag) and copper oxide (CuO) NPs and to prepare NP-modified paint. To this end, AgNPs and CuONPs were biosynthesized using Bacillus atrophaeus spores and commercial and crude dipicolinic acid (DPA) extracted from the spore of this bacterium. The synthesized NPs were characterized using electron microscopy, Fourier-transform infrared (FTIR), X-ray diffraction analysis (XRD), and energy-dispersive X-ray spectroscopy (EDS) methods. A minimum inhibitory concentration (MIC) assay of NPs against Escherichia coli ATCC8739 and Staphylococcus aureus ATCC6538 was carried out. The antibacterial effects of prepared NP–paint complexes were assessed using an optical density (OD) comparison before and after adding metal sheets coated with NP–paint complexes into the nutrient broth medium. Four different types of NPs were synthesized in this research: AgNPs synthesized by spore (A), AgNPs synthesized by commercial DPA (B), AgNPs synthesized by crude DPA (C), and CuONPs synthesized by spore (D). SEM analysis confirmed the spherical shape of NPs. According to the results, NPs A, B, and D showed higher antibacterial activity against S. aureus compared to E. coli. Furthermore, the analysis of the antibacterial effects of NP–paint complexes suggested that paint–NPs A, B, and C displayed higher activity on E. coli compared to S. aureus. Moreover, the antibacterial effect of paint–NP D was significantly lower than other NPs. According to this robust antibacterial effect on pathogenic bacteria, it seems that these NP–paint complexes could be useful in public places such as hospitals, airports, dormitories, schools, and office buildings, where the rate of transmission of infection is high.

This paper investigates the synthesis and characterization of photoactive TiO2/CuO nanocomposites for the simultaneous antibacterial applications and photocatalytic removal of Amoxicilline from wastewaters. Effective removal of biological and organic contaminants from water resources has become a global challenge due to contaminants' complexity and extensive use. TiO2/CuO heterojunctions with different CuO loadings were synthesized using a straightforward precipitation method. Electron microscopy, energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), Fourier transformed infrared (FTIR), ultraviolet–visible (UV-VIS) analyses were used to characterize synthesized samples. Antibacterial activities of samples were investigated against Staphylococcus aureus. Also, the applicability of synthesized powders in the photocatalytic removal of Amoxicilline from wastewater was methodically investigated. Results showed that the photocatalytic activity of synthesized TiO2/CuO nanocomposites is highly dependent on the CuO loadings of samples. CuO loading can also increase the light absorption within the visible light region, making TiO2/CuO samples applicable in the visible light region. Results also showed that CuO loading greatly enhances the antibacterial characteristics of samples.

Recently Bacillus spp. has gained much attention as potential probiotics due to the production of resistant cells. So, this research is purposeful for evaluation of probiotic characteristics of Bacillus isolates from camel milk as a suitable source for growth and isolation of microorganisms that can be candidate to be used as probiotic. First, forty-eight colonies were screened by using morphological and biochemical analysis. Among the isolates, two of them were recognized as Bacillussubtilis CM1 and CM2 by partial 16SrRNA sequencing that, probiotic potentials of them were evaluated. Both of them, in the preliminary safety screening, were found negative for hemolysis and lecithinase activity. Also, in vitro characteristics such as acid, bile salts and artificial gastric juice resistant, cell surface hydrophobicity, auto-aggregation, antioxidant characteristics, and adherent capability to HT-29 cells were determined for them approximately in the range of other probiotic strains. Two strains were susceptible to various antibiotics and enterotoxigenic activities were not detected by PCR which means isolated Bacillus strains could be classified as safe. Altogether, results demonstrate that Bacillus CM1 and CM2 strains could have the potential of consideration as probiotics, however more extensive in vitro/vivo studies are needed.

Pectin, a diverse carbohydrate polymer in plants consists of a core of α-1,4-linked D-galacturonic acid units, includes a vast portion of fruit and agricultural wastes. Using the wastes to produce beneficial compounds is a new approach to control the negative environmental impacts of the accumulated wastes. In the present study, we report a pectinase producing bacterium Streptomyces hydrogenans YAM1 and evaluate antioxidative and anticancer effects of the oligosaccharides obtained from pectin degradation. The production of oligosaccharides due to pectinase activity was detected by thin layer chromatography (TLC) and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Our results revealed that S. hydrogenans YAM1 can degrade pectin to unsaturated pectic oligo-galacturonic acids (POS) with approximately 93% radical scavenging activity in 20 mg/mL which it is more than 50% of the same concentration of pectin. Flow cytometric analysis revealed that MCF-7 cells viability decreased more than 32 and 92% following treatment with 6 and 20 mg/mL POS after 24 h, respectively. It is suggested that pectin degradation by S. hydrogenans YAM1 is not only a new approach to produce highly active compounds from fruit wastes, but also is an effective method to remove fibrous pollutants from different environments.

Pectin is one of the main structural components in fruits and an indigestible fiber made of d-galacturonic acid units with α (1-4) linkage. This study investigates the microbial degradation of pectin in apple waste and the production of bioactive compounds. Firstly, pectin-degrading bacteria were isolated and identified, then pectinolytic activity was assessed by DNS. The products were evaluated by TLC and LC–MS–ESI. The antioxidative effects were investigated using DPPH and anti-cancer effects and cytotoxicity were analyzed by MTT and flow cytometry. In this study two new bacterial isolates, Alcaligenes faecalis AGS3 and Paenibacillus polymyxa S4 with the pectinolytic enzyme were introduced. Structure analysis showed that the products of enzymatic degradation include unsaturated mono, di, tri, and penta galacturonic acids with 74% and 69% RSA at 40 mg/mL for A. faecalis and P. polymyxa S4, respectively. The results of anti-tumor properties on MCF-7 cells by MTT assay, for products of AGS3 and S4 at 40 mg/mL after 48 h, showed 7% and 9% survival, respectively. In the flow cytometric assessment, the compounds of AGS3 at 40 mg/mL were 100% lethal in 48 h and regarding S4 isolate caused 98% death. Cytotoxicity evaluation on L-929 cells showed no significant toxicity on living cells.

Orobol (5,7,3′,4′-tetrahydroxyisoflavone) is a highly hydroxylated isoflavone, which is rarely found in natural environment. In this study, orobol was produced due to bioconversion of a soybean frequented isoflavone, genistein (4′,5,7-Trihydroxyisoflavone) by an active, stable, reusable genetically immobilized enzyme, the recombinant Bacillus subtilis spore displayed tyrosinase. Thin layer chromatography and high performance liquid chromatography were used to monitor the reaction. The results revealed that 1 mM orobol was produced from 3′-hydroxylation of 1 mM genistein by spore displayed tyrosinase at 37°C during 90 min incubation. To study on anti-proliferative effects of orobol, MCF-7 breast cancer cell viability was determined by MTT method and flow cytometric analysis. The comparison between reduction in cell viabilities in 50 to 500 µM genistein and orobol treated cells revealed that orobol has more remarkable anticancer effects than genistein. Flow cytometric analysis showed more than 87% cytotoxicity in 500 µM orobol treated cells by flow cytometric analysis. To the best of our knowledge this is the first report of the orobol demonstrated potent anticancer activity against MCF-7 breast cancer cell. It is suggested that enzymatic biotransformation of soybean genistein to orobol will be made a new approach to create highly bioactive products usable in food and pharmaceutical industries.

Purpose: Simple and cheap diagnostic kit development is one of the important aims of pharmaceutical developers and companies focused on public health improvement. The Bacillus subtilis spore surface-display technique is a genetic engineering method that is used to develop new-generation diagnostic kits applicable for the early detection of various types of diseases. In this study, we developed a novel simple, rapid, and inexpensive diagnostic paper-based kit to detect tyrosine in urine samples of humans and animals that is applicable for home or laboratory use. Methods: The B. subtilis spore-displayed tyrosinase system developed by genetic engineering methods was used to prepare a paper-based kit to detect tyrosine in urine samples of different groups of patients (i.e., patients with diabetes, diabetes with chronic kidney disease (CKD), and chronic kidney disease) for the detection of tyrosine during the acute disease phase. To confirm the sensitivity and specificity of the kit, tyrosine was also detected in urine samples using conventional liquid chromatography/mass spectroscopy. Results: Different concentrations of tyrosine (0.1–1 mM) were detected in urine samples based on visible changes of color from bright brownish-gray to dark brownish-gray within 1 hour. The kit could screen samples to distinguish the three groups of patients based on formation of a broad spectrum of colors reflecting the concentration of tyrosine. Conclusion: To the best of our knowledge, this is the first diagnostic kit with potential to rapidly diagnose various diseases related to the production of tyrosine in biological samples. This kit is not only widely applicable, including for personal use in the home, but is also appropriate as a part of standard screening tests and health protection programs in countries with limited resources.

In this paper, we report removing heavy metal using Bacillus subtilis spore surface display system. We used CotE protein as an anchoring motif because of its high abundance and location in the outer coat layer. And we inserted His12 (double histidine 6 tag) at the C-terminal end of anchoring motif. The proper expression of CotE-His12 fusion protein (22.8 kDa) was confirmed by western blot. We confirmed the surface expression of the CotE-His12 fusion protein using flow cytometry. We tried Ni2+ and Cd2+ adsorption with recombinant spore DB104 (pCotE-His12) and DB104 spore. The amount of adsorbed Ni2+ was 18.2 nmol/mg for DB104 spore and 82.4 nmol/mg for DB104 (pCotE-His12) spore. In the case of Cd2+, the adsorbed amount was 32.6 nmol/mg for DB104 spore and 79.1 nmol/mg for DB104 (pCotE-His12) spore. This means that our spore displayed His12 system can be generally applied for the removal of various kind of heavy metals in the field.

This paper investigates the synthesis, antibacterial, and photocatalytic properties of silver ion-exchanged natural zeolite/TiO

This paper investigates the synthesis, antibacterial, and photocatalytic properties of silver ion-exchanged natural zeolite/TiO2 photocatalyst nanocomposite. Zeolite is known to have a porous surface structure, making it an ideal substrate and framework in different nanocomposites. Moreover, natural zeolite has a superior thermal and chemical stability, with hardly any reactivity with chemicals. Finding an effective and low-cost method to remove both antibiotics and bacteria from water resources has become a vital global issue due to the worldwide excessive use of chemicals and antibiotics. This research aims to propose a facile method to synthesize Ag-ion-exchanged zeolite/TiO2 catalyst for anti-bacterial purposes and photocatalytic removal of atibiotics from wastewaters. TiO2 particles were deposited on the surface of natural zeolite. Ag ion exchanging was performed via a liquid ion-exchange method using 0.1 M AgNO3 solution. X-ray diffractometry (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and Fourier-transform infrared spectroscopy (FTIR) were used to evaluate the structure of synthesized powders. Antibacterial activities of samples were assessed, using Staphylococcus aureus ATCC 25923 and Escherichia coli ATCC 25922 by disc diffusion method. It was shown that Ag-containing nanocomposite samples have an improved antibacterial performance in both cases. Results showed that the synthesized catalyst has promising potentials in wastewater treatment.

Tragacanth, a highly branched carbohydrate polymer isolated from Astragalus, is one of the most commonly used gums in food industry. The primary structure of tragacanth is composed of galacturonic acid monomers connected with α 1-4 links, and it is very similar to the pectin. Tragacanth degradation by microorganisms is significant in two aspects: first, food preservation and microbial growth control due to too much use of tragacanth in the food industry, second, therapeutic and pharmaceutical potential of obtained oligosaccharides. In the present study, we report three new strains of bacteria, Acinetobacter guillouiae strain TD1, Kosakonia sacchari strain TD2, and Bacillus vallismortis strain PD1 with the capability of growing in tragacanth as an only source of carbon and energy. The evolutionary history of the isolated strains was analyzed based on 16S rRNA gene sequences in MEGA7 using the neighbor-joining method. The production of di and tri galacturonic acid due to pectinase activities of the strains were detected by thin layer chromatography (TLC) and liquid chromatography/Mass spectroscopy (LC/MS) analysis. Here is the first report of the ability to grow in tragacanth and pectinase activity monitoring in bacteria. Our results revealed that all of the isolated strains are capable of degrading pectin and tragacanth to oligo-galacturonic acids. The obtained products, which have different structures depending on the tragacanth structures and types of pectinolytic enzymes, would show therapeutic and pharmaceutical potentials.

Some patients with candidiasis seek alternatives drug to treat vaginal yeast infection like herbal preparations and probiotics. However, the effectiveness of such treatments has not received much study. In this research, the unique chitinotrophic Bacillus was isolated on shrimp shell from salt lakes and identified as Bacillus altitudinis by 16SRNA sequencing. This strain produced a novel chitin-oligosaccharide material and thermostable chitinase (5.1 units/ml) during 4 days incubation on shrimp shell medium; nevertheless, its growth on nutrient agar was negative. The zymogram showed less than 50 kD protein responsible for chitinase activities. The LC/MS detection of concentrate fermented products showed the production of oligosaccharide during chitin fermentation. As results of shrimp shell degradation, 65.6 mg/l protein, 73.4 mg/l N-acetyl glucose amine, and oligosaccharide were produced. Synergism activities of chitooligosaccharide and chitinase from this strain against fungi and pathogen candida (staining with methylene blue showed that almost 50% of 106 cells were died during 6 h) are promising for new anti-fungal drug with no side effect.

Objective(s): Silver nanostructures have gathered remarkable attention due to their applications in diverse fields. Researchers have recently demonstrated that bacterial spores are capable of reducing silver ions to elemental silver leading to formation of nanoparticles. Materials and Methods: In this study, spores of Bacillus subtilis and Geobacillus stearothermophilus were employed to produce silver nanoparticles (SNPs) from silver nitrate (AgNO3) through a green synthesis method. The production of SNPs by spores, heat inactivated spores (microcapsule) and spore extracts was monitored and compared at wavelengths between 300 to 700 nm. The biosynthesized SNPs by spore extracts were characterized and confirmed by XRD and TEM analyses. Results: UV-Visible spectroscopy showed that the spore extracts were able to synthesize more SNPs than the other forms. The XRD pattern also revealed that the silver nanometals have crystalline structure with various topologies. The TEM micrographs showed polydispersed nanocrystal with dimensions ranging from 30 to 90 nm and 15 to 50 nm produced by spore extracts of B. subtilis and G. stearothermophilus, respectively. Moreover, these biologically synthesized nanoparticles exhibited antimicrobial activity against different opportunistic pathogens. Conclusion: This study suggests the bacterial spore extract as a safe, efficient, cost effective and eco-friendly material for biosynthesis of SNPs.

This paper investigates a severe microbiologically influenced failure in the elbows of a buried amine pipeline in a petrochemical plant. Pipelines can experience different corrosion mechanisms, including microbiologically influenced corrosion (MIC). MIC, a form of biodeterioration initiated by microorganisms, can have a devastating impact on the reliability and lifetime of buried installations. This paper provides a systematic investigation of a severe MIC-related failure in a buried amine pipeline and includes a detailed microstructural analysis, corrosion products/biofilm analyses, and monitoring of the presence of causative microorganisms. Conclusions were drawn based on experimental data, obtained from visual observations, optical/electron microscopy, and Energy-dispersive X-ray spectroscopy (EDS)/X-Ray Diffraction (XRD) analyses. Additionally, monitoring the presence of causative microorganisms, especially sulfate-reducing bacteria which play the main role in corrosion, was performed. The results confirmed that the failure, in this case, is attributable to sulfate-reducing bacteria (SRB), which is a long-known key group of microorganisms when it comes to microbial corrosion.

Tyrosinases, copper-containing monooxygenases, are widely used enzymes for industrial, medical, and environmental applications. We report the first functional surface display of Bacillus megaterium tyrosinase on Bacillus subtilis spores using CotE as an anchor protein. Flow Cytometry was used to verify surface expression of tyrosinase on the purified spores. Moreover, tyrosinase activity of the displayed enzyme on B. subtilis spores was monitored in the presence of L-tyrosine (substrate) and CuSO4 (inducer). The stability of the spore-displayed tyrosinase was then evaluated after 15 days maintenance of the spores at room temperature, and no significant decrease in the enzyme activity was observed. In addition, the tyrosinase-expressing spores could be repeatedly used with 62% retained enzymatic activity after six times washing with Tris-HCl buffer. This genetically immobilized tyrosinase on the spores would make a new advance in industrial, medical, and environmental applications.

Copper oxide particles have found applications as strong photocatalytic antibacterial agents in recent years. This paper investigates the facile chemical bath deposition synthesis and antibacterial properties of nanocrystalline CuO, CuO-GO, and CuO-GO-Ag nanocomposites. CuO samples were synthesized through a chemical bath deposition method and the introduction of GO nanosheets and silver nanoparticles into the precursor solutions was used to obtain CuO-GO and CuO-GO-Ag nanocomposites. Scanning electron microscope, energy dispersive spectroscopy, elemental mapping, and Fourier-transform infrared spectroscopy were used to characterize synthesized specimens. Antibacterial properties of the nanocomposites were examined against Gram-positive Staphylococcus aureus ATCC 25923 and Gram-negative Escherichia coli ATCC 25922 by the disc diffusion method and minimum inhibitory concentration (MIC) measurements. CuO particles with monoclinic crystallographic structure and crystallite size of 10 nm were synthesized. Synthesized particles were spherical with a narrow size distribution, between 5 and 10 μm. Minor addition of GO to the precursor solution resulted in less agglomeration of nanocomposite powders. CuO-GO-Ag nanocomposite showed noticeable enhanced antibacterial activities against the tested bacteria under visible light, resulting in MIC of 2.6 ± 0.5 mg/ml against Gram-positive and Gram-negative bacteria and also higher inhabitation zone compared to CuO and CuO-GO nanocomposites.

The biological synthesis methods have been emerging as a promising new approach for production of nanoparticles due to their simplicity and non-toxicity. In the present study, spores of Bacillus athrophaeus were used to achieve the objective of developing a green synthesis method of silver nanoparticles. Enzyme assay revealed that the spores and their heat inactivated forms (microcapsules) were highly active and their enzymatic contents differed from the vegetative cells. Laccase, glucose oxidase, and alkaline phosphatase activities were detected in the dormant forms, but not in the vegetative cells. Although no nanoparticle was produced by active cells of B. athrophaeus, both spores and microcapsules were efficiently capable of reducing the silver ions (Ag⁺) to elemental silver (Ag⁰) leading to the formation of nanoparticles from silver nitrate (AgNO₃). The presence of biologically synthesized silver nanoparticles was determined by obtaining broad spectra with maximum absorbance at 400 nm in UV-visible spectroscopy. The X-ray diffraction analysis pattern revealed that the nanoscale particles have crystalline nature with various topologies, as confirmed by transmission electron microscopy (TEM). The TEM micrograph showed the nanocrystal structures with dimensions ranging from 5 to 30 nm. Accordingly, the spore mixture could be employed as a factory for detoxification of heavy metals and subsequent production of nanoparticles. This research introduces an environmental friendly and cost effective biotechnological process for the extracellular synthesis of silver nanoparticles using the bacterial spores.

Tyrosinases, copper-containing monooxygenases, are widely used enzymes for industrial, medical, and environmental applications. We report the first functional surface display of Bacillus megaterium tyrosinase on Bacillus subtilis spores using CotE as an anchor protein. Flow Cytometry was used to verify surface expression of tyrosinase on the purified spores. Moreover, tyrosinase activity of the displayed enzyme on B. subtilis spores was monitored in the presence of L-tyrosine (substrate) and CuSO

For over three decades, methyl-tert-butyl ether (MTBE) has been used as an additive to either increase the octane number in high and medium grade gasoline in substitution of tetraethyl lead or to raise its oxygen content. However, the fate of MTBE in the environment is a great concern. In this work, biomass of novel toluene degradator Exiguobacterium, isolated from toluene enriched seawater, could utilize MTBE by 72% and produced CO2 and formate during degrada tion. Production of ketone and tert-butyl alchol (TBA) has not been seen by gas chromatogra phy (GC). Degradation of MTBE has been seen in aerobic and anaerobic conditions from 4 to 30 °C. It is interesting that the highest degradation occurred during growth in aerobic and cold condition (4 °C). This suggested that in cold areas Exiguobacterium is a very good candidate to degrade MTBE. Since this novel isolate could tolerate high salt, it is useful for removal of MTBE from seawater.

Seeking for simple, rapid, and environmental-friendly routes to produce metal nanoparticles is quite attractive for various biotechnological applications. Biological synthesis method of silver nanoparticles has been found very promising due to their non-toxicity and simplicity. Here, the spores of Bacillus stratosphericus isolated from soil enriched with 30 % H2O2 were used for the production of silver nanoparticles. Furthermore, the possible mechanism of silver nanoparticle synthesis by the spores was elucidated for the first time. In this regard, dipicolinic acid (DPA) was shown to play a critical role as a nanoparticle-producing agent. UV–Vis absorption spectroscopy, X-ray diffraction technique, energy-dispersive spectroscopy, and transmission electron microscopy were used to characterize the nanoparticles. Unlike vegetative cells of B. stratosphericus, the spores and the purified DPA were capable of producing nanoparticles from silver nitrate (AgNO3). These biogenic nanoparticles, which were highly toxic against different pathogenic bacteria, showed mixed structures including spherical, triangular, cubic, and hexagonal with the approximate size between 2 and 20 nm in diameter. Our results illustrated the role of dipicolinic acid as a main factor for the synthesis of nanoparticles by the bacterial spores.

Background: Toluene is a cyclic aromatic hydrocarbon which is widely used as an industrial feedstock and as a solvent. It is one of the major parts of pollution in oil-contaminated environments. Objectives: The main aim of this study was to isolate and characterize a Bacterium with high potential application in toluene bioremediation. Materials and Methods: To isolate a toluene-degrading Bacterium, several seawater and wastewater samples were added to toluene-containing basal salt media (BSM). The isolate was identified by morphological features, biochemical tests, and molecular characterization. Also, physiological characteristics of the isolated strain were determined. Results: The isolate represented the capability of growing on toluene under both aerobic and anaerobic conditions. Moreover, this Bacterium could also use different toxic compounds as the sole sources of carbon and energy. Sequence analysis of 16S rDNA showed that the isolated strain was closely related to Uncultured Bacterium clone A1-E3_M13R (98%) and was submitted as Bacterium Ex-DG74 in NCBI. Bacterium Ex-DG74 showed a tolerance to organic solvent and saline conditions as it could grow in the medium containing over 15% toluene (v/v) and NaCl (w/v), and degraded 79% and 45% of toluene (1% (v/v)) in aerobic and anaerobic conditions, respectively. Conclusions: In this investigation we succeeded to isolate a novel toluene-degrading Bacterium from wastewater. This isolated strain could be considered as a biological material for the toluene bioremediation.

Laccases are effective biocatalysts for various biotechnological applications. Treatment of effluents containing phenol components such as toluene using fungal laccases is usually limited to the acid to neutral pH range and moderate temperatures. In this research, severalBacilli sp., were isolated from marine environment in toluene enriched media in purpose to obtain high laccase activities in spore forming bacteria. Among all the identified isolates,Bacillus sp. XJT-7 removed more toluene in contrast with other strains. The isolatedBacillus grew on toluene as the sole source of carbon and energy with maximum laccase activity and compared with Bacillus sphaericus (ATCC: CCM2177) as a standard strain which has laccase activity without any growth on toluene. Laccase activities in spore ghosts which mislay their germination power by heat shock have been investigated. The results showed that the vegetative cell free spore ghosts had thermostable laccase activities and remained active at 100°C shock. These heated spores (spore ghosts) are useful in biodegradation due to a high laccase activity. The image of Atomic Force Microscopy (AFM) showed that the spore ghosts have 50 nm pores which are good for drug delivery and drug synthesis with laccase activity without any chances for having spore germination. Key words: Bacillus sp., spore ghost, Laccase, atomic force microscopy (AFM).