Biogenically synthesized porous TiO2 nanostructures for advanced anti-bacterial, electrochemical, and photocatalytic applications.

This study develops environmentally benign capping technique to synthesize nanoparticles of Curcuma longa-coated titanium dioxide (CR-TiO2) from titanium isopropoxide by utilizing the extract of Rosa rubiginosa flowers as reducing and chelating agent. The biogenically synthesized nanoparticles revealed excellent anti-bacterial, electrochemical, and photocatalytic properties due to the presence of porous TiO2 nanostructures. The sharp peaks by XRD pattern showed the crystallinity and phase purity of TiO2 nanoparticles. BET analysis proved mesoporous nature of the materials with specific surface area of 134 m2 g -1. The vibrational spectra suggest hydroxyl groups from flavonoids of Curcuma longa acting as functionalizing agent for TiO2 nanoporous structures with visible luminescence, which is proven in fluorescence spectra and is applicable for photocatalytic studies. The anti-bacterial studies showed good inference on TiO2 nanoparticles against Pseudomonas auruginosa and proved it to be an excellent antipseudomonal agent with the oxidative potential. The maximum degradation of phenol red dye in the presence of TiO2 under visible light conditions was observed. The supercapacitor fabricated using the biogenic TiO2 three-electrode system exhibited a specific capacitance of 128 Fg-1 (10 mV s-1), suggesting it as an excellent electrode material. The LSV curve at 50 mV s-1 scan rate showed that oxygen reduction potential (ORR) of CR-TiO2 electrodes was 121 mV. The present study is a new application of nanoparticles in sustainability consideration of the environment as well as a solution to the power crisis with fewer limitations. The well-distinguished antidiabetic and BSA denaturation potential suggests that these porous TiO2 nanostructures can be useful for drug delivery as glucose inhibitors and oral anti-inflammatory drugs with the restriction of adverse side effects.

Iron-tannic acid nano-coating: A promising treatment approach for enhancing Lactococcus lactis antibiotic resistance.

The objective of this study was to explore a novel methodology for the synthesis of nanocoated probiotics following their collection and cultivation under optimized conditions, in light of their significant contribution to human health. Probiotics are instrumental in sustaining immune health by modulating the gastrointestinal microbiota and facilitating digestion. However, the equilibrium they maintain can be adversely affected by antibiotic treatments. It is critical to investigate the vulnerability of probiotics to antibiotics, considering the potential implications. This research aimed to assess whether nanoparticle coating could augment the probiotics' resistance to antibiotic influence. A strain of Lactococcus lactis (L. lactis) was isolated, cultured, and comprehensively characterized utilizing state-of-the-art methodologies, including the VITEK® 2 compact system, VITEK® MS, and 16S rRNA gene sequencing. The nanoparticle coating was performed using iron (III) chloride hexahydrate and tannic acid, followed by an evaluation of the probiotics' resistance to a range of antibiotics. The analysis through scanning electron microscopy (SEM) and atomic force microscopy (AFM) demonstrated a partial nanoparticle coating of the probiotics, which was further supported by UV/Vis spectroscopy findings, suggesting enhanced resistance to standard antibiotics. The results revealed that this strain possesses a unique protein profile and is genetically similar to strains identified in various other countries. Moreover, nano-encapsulation notably increased the strain's resistance to a spectrum of standard antibiotics, including Benzylpenicillin, Teicoplanin, Oxacillin, Vancomycin, Tetracycline, Rifampicin, Erythromycin, and Clindamycin. These findings imply that nanoparticle-coated probiotics may effectively counteract the detrimental effects of extended antibiotic therapy, thus preserving their viability and beneficial influence on gastrointestinal health.

Evaluation of stability of (1R,2 S)-(-)-2-methylamino-1-phenyl-1-propanol hydrochloride in plasma and urine samples-inoculated with Escherichia coli using high-performance liquid chromatography (HPLC).

The preservation of drug stability in biological evidence during the processes of collection and storage poses a substantial obstacle to the progress of forensic investigations. In conjunction with other constituents, the microorganisms present in the samples play a vital role in this investigation. The present investigation employed the high-performance liquid chromatography (HPLC) technique to assess the stability of (1R,2 S)-(-)-2-methylamino-1-phenyl-1-propanol hydrochloride in plasma and urine samples that were inoculated with Escherichia coli. These samples were subjected to storage conditions of 37 °C for 48 h and - 20 °C for a duration of 6 months. Minimal inhibitory concentration (MIC) and Minimal bactericidal concentration (MBC) of MPPH against E. coli were determined using microdilution method. The stability of MPPH in plasma and urine samples inoculated with E. coli was investigated using HPLC method. The results showed the MIC and MBC of MPPH were 87.5 ± 25 ppm and 175 ± 50 ppm, respectively. While MPPH remained stable in plasma for 48 h at 37 °C, it showed a notable decrease of about 11% in stability when stored in urine for the same period and temperature. From the beginning of the first month, a decrease in the stability of the compound appeared in all samples that were stored at - 20 °C, and the decrease reached 7% for plasma samples and about 11% for urine samples. The decrease in the stability reached its peak in the sixth month, reaching more than 30% and 70% of plasma and urine samples preserved at - 20 °C. This work concluded that E. coli can negatively affect the stability of MPPH in plasma and urine samples. This may lead to incorrect conclusions regarding the analysis of biological samples in criminal cases.

Synthesis and characterization of marine seagrass (Cymodocea serrulata) mediated titanium dioxide nanoparticles for antibacterial, antibiofilm and antioxidant properties.

Cymodocea serrulata mediated titanium dioxide nanoparticles (TiO2 NPs) were successfully synthesized. The XRD pattern and FTIR spectra demonstrated the crystalline structure of TiO2 NPs and the presence of phenols, flavonoids and alkaloids in the extract. Further SEM revealed that TiO2 NPs has uniform structure and spherical in shape with their size ranged from 58 to 117 nm. Antibacterial activity of TiO2 NPs against methicillin-resistant Staphylococcus aureus (MRSA) and Vibrio cholerae (V. cholerae), provided the zone of inhibition of 33.9 ± 1.7 and 36.3 ± 1.9 mm, respectively at 100 µg/mL concentration. MIC of TiO2 NPs against MRSA and V. cholerae showed 84% and 87% inhibition at 180 µg/mL and 160 µg/mL respectively. Subsequently, the sub-MIC of V. cholerae demonstrated minimal or no impact on bacterial growth at concentration of 42.5 µg/mL concentration. In addition, TiO2 NPs exhibited their ability to inhibit the biofilm forming V. cholerae which caused distinct morphological and intercellular damages analysed using CLSM and TEM. The antioxidant properties of TiO2 NPs were demonstrated through TAA and DPPH assays and exposed its scavenging activity with IC50 value of 36.42 and 68.85 µg/mL which denotes its valuable antioxidant properties with potential health benefits. Importantly, the brine shrimp based lethality experiment yielded a low cytotoxic effect with 13% mortality at 100 µg/mL. In conclusion, the multifaceted attributes of C. serrulata mediated TiO2 NPs encompassed the antibacterial, antioxidant and anti-biofilm inhibition effects with low cytotoxicity in nature were highlighted in this study and proved the bioderived TiO2 NPs could be used as a promising agent for biomedical applications.

The transmutation of Escherichia coli ATCC 25922 to small colony variants (SCVs) E. coli strain as a result of exposure to gentamicin.

BACKGROUND: Small colony variants (SCVs) are biotypes of bacteria that have a size of approximately one-tenth or less of the wild types and has distinct characteristics comparing to the wild type strains. Clinical SCVs are usually associated with persistent infection and require a long-term treatment program with antibiotics. In Saudi Arabia, there are few studies about SCVs Escherichia coli for this reason, this study is aimed to investigate the ability of gentamicin to mutate E. coli ATCC 25922 to produce small SCVs and investigate the genotypes and phenotypes changes and stress tolerance comparing to clinical SCVs E. coli and normal clinical E. coli Isolated from blood samples. METHODS: In this investigation, four clinical blood samples were collected ted from patients and the cultivation and isolation were carried out in KFMC between December 2019 and February 2021. The identification of positive blood culture samples was done using phoenix MD. Non-SCV E. coli ATCC25922 were mutated to SCV using exposure to increasing gradual concentrations of gentamicin at 100-generation intervals. Biochemical features and susceptibility to standard antibiotics using automated Phoenix MD 50 and. The survival assays were done using several stresses including heat shock, low pH, high osmotic pressure, and oxidative pressure. Virulence genes screening included the detection of genes that encoded to α-haemolysin, CS12 fimbriae, F17-like fimbrial adhesion, P-related fimbriae, yersiniabactin siderophore system, P-fimbriae, aerobactin, iron-regulated genes using PCR and gel electrophoresis. RESULTS: The data from the mutating E. coli ATCC 25922 small colony test with gentamicin revealed that the first emergence of the multidrug resistance (MDR) SCV E. coli strain occurred at generation number 250, corresponding to a gentamicin concentration of 57 g/ml. Pathogenicity islands detection revealed that all tested E. coli strains have PAI IV 536 genes on their chromosomes furthermore, mutated SCV E. coli ATCC 25922 acquired PAII CFT073 and PAI IV 536. Survival tests showed no significant differences changes in tolerance of mutated SCVs comparing to parental strain. CONCLUSION: The present work concluded that gentamicin sub-MIC concentration gradual exposure can induce mutation responsible for SCV formation and evolving of MDR E. coli strains. The mutated SCVs evolved high-level aminoglycoside resistance for gentamicin and resistance to amikacin, it also developed resistance to 2 cephalosporin antibiotics cefuroxime, and cephalothin and a resistance to aztreonam.

The Prevalence of the Virulence Genes of Staphylococcus aureus in Sickle Cell Disease Patients at KSUMC, Riyadh, Saudi Arabia.

Staphylococcus aureus in the blood of sickle cell disease (SCD) patients may result in a significant increase in morbidity and mortality. S. aureus strains contain various virulence characteristics, including the ability to create a variety of toxins and develop drug resistance. The current study sought to assess the prevalence of S. aureus in SCD patients and to identify the pathogen's virulence characteristics. Between 2017 and 2021, blood samples and data were collected at King Saud University Medical City (KSUMC) in Riyadh, Saudi Arabia. The Vitek system PCR and gene sequencing methods were used for identification, antibiotic resistance patterns, and genetic analysis. During the study period, 47 S. aureus blood isolates (methicillin-resistant S. aureus (MRSA) 41.6% and non-MRSA 58.4%) were isolated from 2406 SCD patients. The prevalence percentages of virulence genes (finbB, sdrC, sdrD, icaA, coa, nuc, hlg, hla, finbA, clfA, efb, pvl, agr, spa, seb, sea, sec, tst, and sed) among all the isolates from the SCD patients compared with non-SCD patients (control group) were as follows: (100% vs. 100%), (100% vs. 100%), (100% vs. 100%), (100% vs. 87.5%), (100% vs. 81.3%), (100% vs. 100%), (100% vs. 100%), (100% vs. 100%), (97.9% vs. 81.3%), (97.9% vs. 100%), (97.9% vs. 87.5%), (54.3% vs. 56.3%), (46.8% vs. 75%), (42.6% vs. 43.8%), (27.7% vs. 0%), (25.5% vs. 12.5%), (12.8% vs. 6.3%), (4.3% vs. 12.5%), and (4.3% vs. 0%). Regarding the resistance genes (plaZ, mecA, ermA, ermC, tetK, tetM, and ermB) of the S. aureus strains isolated from the SCD patients compared with non-SCD patients (control group), the prevalence percentages were as follows: (100% vs. 100%), (100% vs. 56.3%), (0% vs. 31.3%), (31.9% vs. 18.8%), (40.4% vs. 25%), (0% vs. 0%), and (0% vs. 0%). As for the antibiotic (ampicillin, penicillin, amoxicillin, cefazolin, imipenem, oxacillin, erythromycin, tetracycline, azithromycin, ciprofloxacin, moxifloxacin, and levofloxacin) resistance of the S. aureus strains isolated from the SCD patients compared with non-SCD patients (control group), the prevalence percentages were as follows: (100% vs. 100%), (97.9% vs. 100%), (72.3% vs. 25%), (68.1% vs. 37.5%), (68.1% vs. 25%), (66% vs. 25%), (36.2% vs. 18.8%), (23.4% vs. 12.5%), (19.1% vs. 12.5%), (17% vs. 12.5%), (14.9% vs. 25%), and (10.6% vs. 18.7%). This study concluded that several virulence genes were present in the S. aureus strains recovered from the SCD patients at KSUMC, with all the isolates containing the finbB, sdrC, sdrD, icaA, coa, nuc, hlg, and hla genes.

Stability of (1R,2S)-(-)-Ephedrine hydrochloride in Candida albicans-inoculated urine and blood samples.

The stability of drugs in biological evidence during collection and storage is of particular concern in forensic investigations. Microbes in the samples and other elements are an essential component of these investigations. In the current study, the HPLC method was used to examine the stability of (1R, 2S)-(-)-Ephedrine hydrochloride in plasma and urine samples inoculated with C. albicans after storage at 37 °C for 48 h and -20 °C for six months. In the stability experiment, MIC50% of (1R, 2S)-(-)-Ephedrine hydrochloride was applied according to MIC and MFC that were determined in this work. This drug had MIC and MFC of 50 and 100 ppm, respectively. In HPLC analysis, the standard (1R, 2S)-(-)-Ephedrine hydrochloride had a retention time of 1.63 and was used to identify this drug in samples that had or had not been exposed to C. albicans. The findings demonstrated that within 48 h at 37 °C, C. albicans had an impact on the drug concentration (10% and more than 15%, respectively, were lost in plasma and urine samples inoculated with C. albicans). In plasma samples, the drug content remained stable at -20 °C for three months, although it degraded in urine samples after one month. In plasma and urine samples, the concentration reduction had surpassed 70% and 50% by the sixth month, respectively. The results of this investigation show that C. albicans can change the stability of (1R, 2S)-(-)-Ephedrine hydrochloride in plasma and urine samples that contain MIC50% of Ephedrine hydrochloride.

Biosynthesis of silver nanoparticles (Ag-NPs) using Senna alexandrina grown in Saudi Arabia and their bioactivity against multidrug-resistant pathogens and cancer cells.

There is no doubt that the risk of drug-resistant pathogens and cancer diseases is on the rise. So, the goal of this study was to find out how effective silver nanoparticles (Ag-NPs) made by Senna alexandrina are at fighting these threats. In this work, S. alexandrina collected from Medina, Saudi Arabia was used and the biosynthesis method was applied to produce the Ag-NPs. The characterization of Ag-NPs was done using different analytical techniques, including UV spectroscopy, FT-IR, TEM, and XRD analysis. The MIC, MBC, and MTT protocols were applied to confirm the bioactivity of the Ag-NPs as antibacterial and anticancer bioagents. The findings reported indicating that the aqueous extract of S. alexandrina leaves, grown naturally in Saudi Arabia, is ideal for the production of bioactive Ag-NPs. The hydroxyl, aliphatic, alkene, N-H bend of primary amines, C-H bonds, and C-O bonds of alcohol were detected in this product. The small, sphere-shaped particles (4-7 nm) were the most prevalent among the bioactive Ag-NPs produced in this work. These nanoparticles inhibited some important multidrug-resistant pathogens (MDRPs) (Escherichia coli, Acinetobacter baumanii/haemolyticus, Staphylococcus epidermidis, and Methicillin-resistant Staphylococcus aureus (MRSA)), as well as their ability to inhibit breast cancer cells (MCF-7 cells). The MIC of Ag-NPs ranged from 0.03 to 0.6 mg/mL, while their MBC ranged from 0.06 to 2.5 mg/mL. Anticancer activity test showed that IC50 of the Ag-NPs against tested breast cancer cells was 61.9 ± 3.8 µg/mL. According to the current results, biosynthesis using S. alexandrina leaves grown naturally in Saudi Arabia was an ideal technique for producing bioactive Ag-NPs that could be used to combat a variety of MDRPs and cancer diseases.

Metal tolerance and biosorption of Pb ions by Bacillus cereus RMN 1 (MK521259) isolated from metal contaminated sites.

Recent years, metal pollution is an alarming factor to know about protects the environmental ecosystem due to the toxic, persistent and abundant in nature. Metals are present everywhere in the biotic and abiotic samples including soil, water, and microbes. The rate of bioaccumulation and biotransformation are very high. The excess concentration of the metals causes heavy metal pollution or contamination. Due to these defects, the removal of metals using biological sources is heightened in the current research. In this current investigation, the biosorption potential ability of the metal tolerable Bacillus cereus on Pb and Cu rich environment was chosen and thoroughly monitored. The 16s rRNA of the Bacillus cereus was sequenced, and named as Bacillus cereus RMN 1 (MK521259). The various test concentration (10-60 mg/mL) of Pb and Cu was exhibited the maximum removal percentages of 85.2% and 60.2%. The result of bisorption factors exhibited, 300 mg/mL of the biosorbent potency, 60 min contact time and pH 7, and they found to be optimal to remove the maximum of Pb ion from the solution. In the regression coefficients, the Freundlich and Langmuir isotherm models were used to study the adsorption kinetics of metal ions. In addition, the isotherm model confirmed that the of B. cereus biomass medicated metal adsorption was more favourable reaction for metal degradation. With the above evidences, the results of the present investigation proved that B. cereus derived biomass was actively adsorbing the metals ions. Thus we are recommending for the implementation of effective waste water treatment.

Streptomyces sp. 1S1 isolated from Southern coast of the Red Sea as a renewable natural resource of several bioactive compounds.

Red Sea represents one of the most remarkable marine ecosystems. However, it is also one of the world's least explored areas of marine biodiversity. The aims of this investigation were therefore, to isolate marine microorganisms from the seashore sediments and water in shallow region from west Yemen coast, to assess their antimicrobial potential, to identify the highly active isolate, and to purify and identify the bioactive compounds from it. In this regard, twenty-five bacterial strains have been isolated from twenty samples and tested for their antimicrobial ability against some pathogenic bacteria and yeast by using the agar disk diffusion and agar well diffusion assay. Out of the total 25 marine actinomycetes isolates only 13 exhibited interesting antimicrobial activity. The morphological, biochemical, and phylogenetic characteristics of the potential isolate 1S1 were compatible with their classification in the genus Streptomyces. The 16S rRNA gene sequences have shown that the isolate 1S1 clustered with Streptomyces longisporoflavus. The strain Streptomyces sp. 1S1 was cultivated and extracted with ethyl acetate. The GC-MS study of the extract indicated the presence of certain fatty acyl compounds e.g., tetradecanoic acid, 9-octadecenoic acid, hexadecanoic acid, and 9,12,15-octadecatrienoic acid. Using chromatographic techniques, three compounds were isolated and by spectroscopic methods e.g., IR, MS and NMR structurally elucidated. The three compounds were identified as a triacylglyceride, 9-octadecenoic acid, and hexadecanoic acid. The study reinforces the evidence of the potential of Streptomyces sp and the ability to produce several antimicrobial compounds.

Biosorption and adsorption isotherm of chromium (VI) ions in aqueous solution using soil bacteria Bacillus amyloliquefaciens.

This study looked at the development of effective biosorbents to recover the most toxic elements from industrial water. B. amyloliquefaciens was isolated from marine soils showing extreme resistance to Chromium (Cr(VI)) ions. During the 60 min of contact time, 79.90% Cr(VI) was adsorbed from the aqueous solution. The impact of important factors such as biomass concentration, pH of the medium, and initial metal ions concentration on biosorption rate was also examined. The desorption study indicated that 1 M HCl (91.24%) was superior to 0.5 M HCl (74.81%), 1 M NaOH (64.96%), and distilled water (3.66%). Based on the Langmuir model, the maximum adsorption capacity of the bio-absorbent was determined to be 48.44 mg/g. The absorption mechanism was identified as monolayer, and 1/n from the Freundlich model falls within 1, thus indicating favorable adsorption. Based on the findings of the present study, the soil bacterium B. amyloliquefaciens was found to be the best alternative and could be used to develop strategies for managing existing environmental pollution through biosorption.

Investigation of interspecies crosstalk between probiotic Bacillus subtilis BR4 and Pseudomonas aeruginosa using metabolomics analysis.

Pseudomonas aeruginosa (PA) is an opportunistic pathogen that causes high mortality in cystic fibrosis patients. Treatment failures often occur due to the emergence of antibiotic resistance. Inhibition of virulence factors production without suppressing the growth of the pathogens is a potential alternative strategy to control the antibiotic resistance. In order to accomplish, three different interaction studies were performed using Bacillus subtilis BR4, PA and their extracellular contents. Firstly, co-cultivation was performed with different cell density of BR4 or PA. In co-culture setup (F), high cell density of BR4 significantly inhibits the biofilm formation of PA in a growth-independent manner (p < 0.01). To substantiate the biofilm inhibition, LC-MS/MS was performed and metabolic profile of monocultures and cocultures were compared. Multivariate analysis corroborated that metabolic profile of coculture setup (F) is drastically different from other coculture and monoculture setups. To check the effect of extracellular content of PA on BR4, supernatant of PA was extracted with ethyl acetate and different concentration of that extract (PA-EXT) was supplemented with BR4 culture. Exogenous supplementation PA-EXT (40 µg/mL) led to increased biofilm inhibitory activity (p < 0.01) in BR4. Further, to check the effect of extracellular content of BR4, PA was grown in the supernatant of BR4. PA survives in the spent media of BR4 without biofilm formation. Though 50% spent media of BR4 was replaced with fresh media, PA could not produce biofilm. In support of this, LC-MS/MS analysis has revealed that abundance of quorum sensing (QS) signals was reduced in the spent media grown PA than control. Furthermore, BR4 protects zebrafish larvae (Danio rerio) against PA infection and increases their survival rate (p < 0.05). We found that PA-induced oxidative stress and apoptosis were also significantly reduced in the BR4-pretreated larval group than control group. These results clearly indicate that BR4 exerts growth-independent QS inhibition in PA, suggesting that it could be used as a probiotic for future therapeutic interventions.

Swift synthesis of zinc oxide nanoparticles using unripe fruit extract of Pergularia daemia: An enhanced and eco-friendly control agent against Zika virus vector Aedes aegypti.

In this study Pergularia daemia unripe fruits were used to synthesize zinc oxide nanoparticles (Pd-ZnONPs). UV-vis Spectroscopy detected the production of ZnONPs. XRD, FTIR, SEM, and TEM studies were used to characterize the synthesized Pd-ZnONPs. Aedes aegypti (Ae. aegypti) third instar larvae were analyzed to diverse concentrations of Pd-unripe fruit extract and Pd-ZnONPs for 24 hours to assess the larvicidal effect. Mortality was also detected in Ae. aegypti larvae under laboratory conditions, with corresponding LC50 and LC90 values of 11.11 and 21.20 µg/ml respectively. As a result of this study, the levels of total proteins, esterases, acetylcholine esterase, and phosphatase enzymes in the third instar larvae of Ae. aegypti were significantly lower than the control. These findings suggest that Pd-ZnONPs could be used to suppress mosquito larval populations.

Molecular interaction analysis of ß-1, 3 glucan binding protein with Bacillus licheniformis and evaluation of its immunostimulant property in Oreochromis mossambicus.

Analyzing the health benefits of any two immunostimulants (synbiotics) in combined form and information on their interactions gain more visibility in the usage of synbiotics in aquafarms. With this intention, the current work explores the immunostimulant effect and structural interaction of synbiotic (ß-1, 3 glucan binding protein from marine crab, Portunus pelagicus (Ppß-GBP) and Bacillus licheniformis) on Oreochromis mossambicus. The experimental diet was prepared with Ppß-GBP and B. licheniformis, and nourished to the fingerlings of O. mossambicus for 30 days. After the experimental trial, a higher growth rate and immune reactions (lysozyme, protease, myeloperoxidase and alkaline phosphatase activity) were noticed in the fish nourished with synbiotic (B. licheniformis and Ppß-GBP) enriched diet. Moreover, the synbiotic enriched diet elevated the antioxidant responses like glutathione peroxidase (GSH-Px) and catalase (CAT) activity in the experimental diet-nurtured fish. At the end of the feed trial, synbiotic diet nourished fish shows an increased survival rate during Aeromonas hydrophila infection, reflecting the disease resistance potential of experimental fish. Also, the interaction between Ppß-GBP and Bacillus licheniformis was analyzed through computational approaches. The results evidenced that, Ppß-GBP interacts with the B. licheniformis through sugar-based ligand, ß-glucan through a hydrogen bond with a good docking score. Thus, the synbiotic diet would be an effective immunostimulant to strengthen the fish immune system for better productivity.

Laccase producing bacteria influenced the high decolorization of textile azo dyes with advanced study.

Recent year, bacterial laccases are increasing interest in the field of industry and environmental applications especially decolorization of azo dyes. In industry, the dyes are present in stable nature including chemicals and lights. Due to these defects, the novel approaches are needed to removal of dyes before discharging into the environment. Among the various technologies, biological treatment methods and their strategies are very important, because of the decolorization and detoxification. Consecutively, biological mediated dyes removal are emerged with high potential especially microbes. Microbial laccases creates up new opportunities for their commercial applications. In this study, laccases were produced from Bacillus cereus (B. Cereus) and Pseudomonas parafulva (P. parafulva) by sub merged fermentation. For immobilization, the produced laccases were subjected to purify using 80% saturated ammonium sulphate and followed by dialysis. Then, crude laccases were immobilized through copper-alginate entrapment method. The maximum immobilized enzyme activity of the immobilized laccases were shown pH 8 at 50 °C and pH 7 at 40 °C for B. Cereus and P. parafulva respectively. In contrast, the normal enzyme activity was pH 10 at 40 °C and pH 8 at 40 °C were indicated for Bacillus cereus and P. parafulva respectively. Next, the free and immobilized laccases were performed the decolorization of three azo dyes T-blue, yellow GR and orange 3R, and exhibited that the 91.69 and 89.21% of Orange 3R were completely decolorized by both the B. Cereus and P. parafulva laccases when compared with free laccases enzymes. The confirmation of decolorization was monitored by UV-vis spectroscopy and FTIR spectroscopy, which clearly confirm the changes of peaks when compared with normal laccases. Finally, we have concluded that the B. Cereus and P. parafulva laccases are very important in azo dye decolorization and these used in future biological treatment of dyeing effluents.

Fabrication of graphene oxide-p-phenylenediamine nanocomposites as fluorescent chemosensors for detection of metal ions.

In this work, graphene oxide-p-Phenylenediamine nanocomposites of two different ratios of Graphene oxide: p-Phenylenediamine (1:1 and 1:5) were prepared and characterized by using analytical, spectroscopic and microscopic studies (GO-pPD 11 and GO-pPD 15). These nanocomposites were employed as fluorescent chemosensors for sensing potential cations. Remarkably, graphene oxide-p-Phenylenediamine nanocomposites of ratio 1:1 (GO-pPD 15) was selective and sensitive to Ag+ ions, whereas the graphene oxide-p-Phenylenediamine nanocomposites of ratio 1:5 (GO-pPD 15) was selective to Ce3+ions. A possible mechanism as switch "off-on" is proposed built on the inhibition of the photo induced electron transfer process in both the fluorescent probes in detecting the metal ions. In addition, interference studies were performed with the help of competitive complexation analysis and no significant interference were found by other potentially competing cations. The pH studies revealed that both the chemosensors can be used at the physiological pH for the ion detection and also the detection time was within 2-3 min. Both the chemosensors show good reversibility and hence the sensors can be used for multiple times. The newer nanocomposites were then utilized in the real water sample analysis as to check its real level application purpose.

Biochemical Profile by GC-MS of Fungal Biomass Produced from the Ascospores of Tirmania nivea as a Natural Renewable Resource.

The edible fruiting bodies of desert truffles are seasonally collected and consumed in many regions of the world. Although they are very expensive, they are bought and sold as a result of considerable scientific reports confirming their health and nutritional benefits. This study aimed to conduct laboratory production of the fungal biomass of Tirmania nivea as a natural renewable resource of many active biological compounds using an artificial growth medium. The T. nivea collected from Hafar Al-Batin, which is north of Saudi Arabia, and their ascospores were harvested and used to produce fungal biomass in potato dextrose broth. The cultivation was conducted using a shaking incubator at 25 °C for two weeks at 200 rpm. The crud extracts of the fungal biomass and mycelium-free broth were prepared using ethyl acetate, methanol and hexane. Preliminary gas chromatography-mass spectrometry (GC-MS) analysis and their biological activity as antimicrobial agents were investigated. The results showed that the crude extracts have biological activity against mold, yeast and bacteria. The preliminary GC-MS analysis reported that the fungal biomass and extracellular metabolites in the growth medium are industrial renewable resources of several biological compounds that could be used as antifungal, antibacterial, antiviral, anticancer, antioxidant, anti-trypanosomal and anti-inflammatory agents.

Partially purified actinomycetes compounds enhance the intracellular damages in multi-drug resistant P. aeruginosa and K. pneumoniae.

Based on the excellent nutrient level, the current study was focused on isolation and anti-bacterial activity of the actinomycetes from marine mangrove soil samples. As result, 10 different strains of actinomycetes strains were identified on actinomycetes isolation agar plates. The identified strains were shown with white, clear, uncontaminated well matured spore producing ability. Based on the initial observation, the isolated colonies were actinomycetes. The partially extracted crude compound shown excellent anti-bacterial activity against P. aeruginosa and K. pneumoniae with 15 mm and 13 mm zone of inhibitions were observed at 500 µL concentrations. The minimum inhibition concentration result was also confirmed the 500 µL concentration against both the tested concentration with high inhibition rate. Then, the intracellular damages, decreased cell growth of the crude actinomycetes extract treated bacterial strains were clearly observed by confocal laser scanning electron microscope. The extracellular damages of bacterial cell wall and shape of the both the pathogens were clearly shown by scanning electron microscope. Therefore, all the results were clearly supported to the partially extracted crude compound and it has excellent anti-bacterial activity against tested multi drug resistant bacteria.

A synergic action of colistin, imipenem, and silver nanoparticles against pandrug-resistant Acinetobacter baumannii isolated from patients.

BACKGROUND: The upgrowth and rapid prevalence of pandrug-resistant Acinetobacter baumannii strains that have a pathogenic activity to cause several infections are of considerable influence on the health of communities worldwide. No infections by these bacterial strains were recorded before 1998, and currently, the numbers are on the rise. METHODS: The A. baumannii strains were isolated from male and female patients in Medical Microbiology Department, King Fahd Medical City (KFMC) in Riyadh, Saudi Arabia between 1/1/2020 to 29/12/2020. The statistical analysis was performed base on sex, age, source of samples, and response to commercially available antibiotics. The A. baumannii strains that resisted all the antibiotics including colistin and imipenem were selected for the synergic test. RESULTS: The data showed that 62.28%, 77.07% of 342 A. baumannii strains were isolated from males and patients over 35 years of age. A. baumannii strains (pandrug-A. baumannii) that can resist all tested antibiotics were 8.19%. The major source of the A. baumannii isolates was the respiratory system (>50%). Among all isolates (N = 342), azidothymidine-resistant A. baumannii strains were more than 85%. There is a statistically significant difference (P < 0.05) in the number of colistin-resistant A. baumannii strains isolated from males comparing with the female. The combinations of colistin and silver nanoparticles or imipenem and silver nanoparticles resulted in synergistic action led to reduction of MICs of colistin, imipenem, and silver nanoparticles (more than four-fold reduction). Also, the combinations of colistin and imipenem had high synergistic action. CONCLUSION: The pandrug-resistant A. baumannii strains may represent a current and future threat that must be fought, and the synergy action of antibiotics and nanoparticles may be one of the available, rapid, and easy strategies to confront this global problem.

Enlightening the characteristics of bioflocculant of endophytic actinomycetes from marine algae and its biosorption of heavy metal removal.

The removal of toxic heavy metal ions from contaminated environments is a great challenge and requires an alternative rapid, efficient, economical bioremediation approach. Henceforth, bioflocculant producing endophytic actinobacterial sp. was isolated from heavy metal contaminated marine environments for heavy metal biosorption process. After molecular characterization, the isolated actinomycete starin was Nocardiopsis sp. GRG 3 (KT235642). It was indicated that the maximum flocculating activity of 80.90% with glucose, and yield is 4.52 g L1. The optimum flocculating activity was reached at pH 7 in the presence of CaCl2 ions. Further, the bioflocculent produced Nocardiopsis sp. GRG 3 (KT235642) was characterized by fourier transform infrared analysis spectra (FTIR) and displayed the presence of carboxyl, hydroxyl, amino groups and characteristic of more polysaccharide and protein. The heavy metal sorption by bioflocculant Nocardiopsis sp. GRG 3 (KT235642) was effectively removed 55.90% Cd, 85.90% Cr, 74.7% Pb, and 51.90% Hg. Therefore, this study was proved that the bioflocculant derived from endophytic actinobacteria, Nocardiopsis sp. GRG 3 (KT235642) as a effective alternative method for decreasing the heavy metals towards sustainable environmental management.