Anti-microbiological activities of bio-synthesized silver Nano-stars by Saccharopolyspora hirsuta

A novel strain of Saccaropolyspora hirsuta was isolated from an insect Tapinoma simrothi for the first time and was morphologically and physiologically characterized. It was genetically identified using 16S rRNA and sequence similarity percentage in genbank with closely related species as strain ess_amA6 of Saccaropolyspora hirsuta. The accession number of strain ess_amA6 is KF996506. Antagonistic activity of strain ess_amA6 against some pathogenic Gram positive and negative bacteria, and unicellular fungus Candida albicans was studied. In addition, star shaped silver nanoparticles were biosynthesized using strain ess_amA6. The silver Nano stars were characterized by UV-us spectrophotometer. Fourier transform infrared spectroscopy analysis confirmed the conversion of Ag+ ions to Nano silver due to the reduction by capping material of extract. Transmission electron microscopically studies of biosynthesized Nano silver particles showed that they are spherical ranging from 10 nm to 30 nm in size. Silver atoms were checked in Nano sample by Energy Dispersive X-ray spectroscopy. Bioactivity of biosynthesized Nano silver was observed against some pathogenic microorganisms such as Staphylococcus aureus, Streptococcus pyogenes, Salmonella typhi, pseudomonas aeruginosa, Klebsiella pneumonia and Candida albicans. These tested microbes were highly sensitive to Nano silver. This study recommended that strain ess_amA6 can be used to effectively biosynthesize bioactive Nano silver compounds. Keywords: Saccharopolyspora hirsute, Nano silver, Antimicrobial, Pathogenic microbe

Extraction and Characterization of Polyhydroxybutyrates (PHB) from Bacillus thuringiensisKSADL127 Isolated from Mangrove Environments of Saudi Arabia

ABSTRACTPolyhydroxybutyrate (PHB) is a renowned biodegradable plastic that do not release any toxins or residues in the environment like petroleum based plastics. In the present study, 50 bacteria isolated from mangrove niche, Saudi Arabia, were screened for maximum PHB production. All the 50 strains showed positive for PHB production, of which one strain showed maximum of 137 mgL-1. The most PHB accumulated bacterium was selected and identified asBacillus thuringiensis KSADL127, based on phenotypic characterization and 16S rRNA sequence analysis. Characterization of extracted PHB was carried out by FT-IR, NMR, UV spectroscopy, DSC, TGA, and LC-MS, which later confirmed the presence of intracellular accumulated polymer and substantiated as PHB

Synthesis, X-ray Crystal Structure and Antimicrobial Activity of Unexpected Trinuclear Cu(II) Complex from s-Triazine-Based Di-Compartmental Ligand via Self-Assembly

The synthesis and X-ray crystal structure of the trinuclear [Cu3(HL)(Cl)2(NO3)(H2O)5](NO3)2 complex of the s-triazine-based di-compartmental ligand, 2-methoxy-4,6-bis(2-(pyridin-2-ylmsethylene)hydrazinyl)-1,3,5-triazine (H2L), are presented. The Cu1 and Cu2 are penta-coordinated with CuN3ClO coordination environment, distorted square pyramidal coordination geometry while Cu3 is hexa-coordinated with CuN2O4 coordination sphere, and distorted octahedral geometry. The complex crystallized in the primitive P-1 triclinic crystal system with two molecular units per unit cell. Its packing is dominated by the O–H (35.5%) and Cl–H (8.8%) hydrogen bonding interactions as well as the π–π stacking (2.3%) and anion–π-stacking interactions (3.7%). The different coordination interactions were analyzed using atoms in molecules (AIM) theory, and the number of charge transferences from the ligand group to Cu(II) were determined using natural bond orbital calculations. The effect of the free ligand and its Cu(II) complex on the tested pathogenic microbes (Staphylococcus aureus, S. epidermidis, Enterococcus faecalis, Escherichia coli, Salmonella typhi and Pseudomonas aeruginosa) and one fungal isolate (Candida albicans) is presented. Both have wide spectrum antimicrobial activity against the selected microorganism. It is observed that the free ligand at 180 µg/mL was more effective than its Cu(II) complex and showed close results compared to the positive control gentamicin. At higher concentrations (1 mg/mL), the Cu(II) complex was found to be more active against S. epidermidis, E. coli and C. albicans than the lower concentration. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values are also lower for the Cu(II) complex than the free ligand.peerReviewe

Synthesis, X-ray Crystal Structure and Antimicrobial Activity of Unexpected Trinuclear Cu(II) Complex from s-Triazine-Based Di-Compartmental Ligand via Self-Assembly

The synthesis and X-ray crystal structure of the trinuclear [Cu3(HL)(Cl)2(NO3)(H2O)5](NO3)2 complex of the s-triazine-based di-compartmental ligand, 2-methoxy-4,6-bis(2-(pyridin-2-ylmsethylene)hydrazinyl)-1,3,5-triazine (H2L), are presented. The Cu1 and Cu2 are penta-coordinated with CuN3ClO coordination environment, distorted square pyramidal coordination geometry while Cu3 is hexa-coordinated with CuN2O4 coordination sphere, and distorted octahedral geometry. The complex crystallized in the primitive P-1 triclinic crystal system with two molecular units per unit cell. Its packing is dominated by the O–H (35.5%) and Cl–H (8.8%) hydrogen bonding interactions as well as the π–π stacking (2.3%) and anion–π-stacking interactions (3.7%). The different coordination interactions were analyzed using atoms in molecules (AIM) theory, and the number of charge transferences from the ligand group to Cu(II) were determined using natural bond orbital calculations. The effect of the free ligand and its Cu(II) complex on the tested pathogenic microbes (Staphylococcus aureus, S. epidermidis, Enterococcus faecalis, Escherichia coli, Salmonella typhi and Pseudomonas aeruginosa) and one fungal isolate (Candida albicans) is presented. Both have wide spectrum antimicrobial activity against the selected microorganism. It is observed that the free ligand at 180 µg/mL was more effective than its Cu(II) complex and showed close results compared to the positive control gentamicin. At higher concentrations (1 mg/mL), the Cu(II) complex was found to be more active against S. epidermidis, E. coli and C. albicans than the lower concentration. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values are also lower for the Cu(II) complex than the free ligand

Chitosan-S-triazinyl-bis(2-aminomethylpyridine) and Chitosan-S-triazinyl-bis(8-oxyquinoline) Derivatives: New Reagents for Silver Nanoparticle Preparation and Their Effect of Antimicrobial Evaluation

Herein, we described the modification of chitosan with cyanuric chloride as a mediator for preparation of chitosan-s-triazinyl-bis(2-aminomethylpyridine) and chitosan-s-triazinyl-bis(8-oxyquinoline) derivatives to be used as reagents for preparation of silver nanoparticles under ecofriendly conditions. These two reagents are convenient and effective for reduction of silver ions to silver nanoparticles with particle size less than 10 nm that might be suitable for industrial and medicinal applications. The formation and particle size of AgNPs are characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), scanning electron microscope (SEM), and energy-dispersive X-ray analysis (EDX). The antimicrobial activity of the two modified chitosan-s-triazine-AgNPs was evaluated against activities against Gram-positive bacteria (M. luteus ATCC 10240 and MRSA ATCC 43300), Gram-negative bacteria (E. coli ATCC 25922 and P. aeruginosa ATCC 75853), and C. albicans. The results showed that chitosan-s-triazinyl-bis(2-aminomethylpyridine) AgNPs showed high antimicrobial activities against all the tested microorganisms, while their analogous chitosan-s-triazinyl-bis(8-oxyquinoline) AgNPs showed moderate activities

Antimicrobial activity of some plant extracts against bacterial strains causing food poisoning diseases

Prevention of food spoilage and food poisoning pathogens is usually achieved by use of chemical preservatives which have negative impacts including: human health hazards of the chemical applications, chemical residues in food & feed chains and acquisition of microbial resistance to the used chemicals. Because of such concerns, the necessity to find a potentially effective, healthy safer and natural alternative preservatives is increased. Within these texts, Plant extracts have been used to control food poisoning diseases and preserve foodstuff. Antimicrobial activity of five plant extracts were investigated against Bacillus cereus, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Salmonella typhi using agar disc diffusion technique. Ethanolic extracts of Punica granatum, Syzygium aromaticum, Zingiber officinales and Thymus vulgaris were potentially effective with variable efficiency against the tested bacterial strains at concentration of 10 mg/ml while extract of Cuminum cyminum was only effective against S. aureus respectively. P. granatum and S. aromaticum ethanolic extracts were the most effective plant extracts and showed bacteriostatic and bactericidal activities against the highly susceptible strains of food borne pathogenic bacteria (S. aureus and P. aeruginosa) with MIC's ranged from 2.5 to 5.0 mg/ml and MBC of 5.0 and 10 mg/ml except P. aeruginosa which was less sensitive and its MBC reached to 12.5 mg/ml of S. aromaticum respectively. These plant extracts which proved to be potentially effective can be used as natural alternative preventives to control food poisoning diseases and preserve food stuff avoiding healthy hazards of chemically antimicrobial agent applications

Synthesis, Characterization, and Antimicrobial Studies of Novel Series of 2,4-Bis(hydrazino)-6-substituted-1,3,5-triazine and Their Schiff Base Derivatives

The present work represents the synthesis, characterization, and antimicrobial studies of novel series of 2,4-bis(hydrazino)-6-substituted-1,3,5-triazine and their Schiff base derivatives. IR, NMR (H1 and C13), elemental analysis, and LC-MS characterized the prepared compounds. The biological activity of the target products was evaluated as well. Twenty-two of the prepared compounds were selected according to their solubility in aqueous DMSO. Only eight compounds showed good activity against the selected pathogenic bacteria and did not show antagonistic effect against fungus Candida albicans. Two compounds 4k and 5g have wide-range effect presently in Gram-positive and Gram-negative bacteria while other compounds (4f, 4i, 4m, 5d, 6i, and 6h) showed specific effect against the Gram-negative or Gram-positive bacteria. The minimum inhibitory concentration (MIC, μg/mL) of 4f, 4i, 4k, and 6h compounds against Streptococcus mutans was 62.5 μg/mL, 100 μg/mL, 31.25 μg/mL, and 31.25 μg/mL, respectively. The MIC of 4m, 4k, 5d, 5g, and 6h compounds against Staphylococcus aureus was 62.5 μg/mL, 31.25 μg/mL, 31.25 μg/mL, 100 μg/mL, and 62.5 μg/mL, respectively. The MIC of 4k, 5g, and 6i compounds against Salmonella typhimurium was 31.25 μg/mL, 100 μg/mL, and 62.5 μg/mL, respectively. The MIC of 6i compound against Escherichia coli was 62.5 μg/mL

Novel 4,6-Disubstituted s-Triazin-2-yl Amino Acid Derivatives as Promising Antifungal Agents

A novel series of 4,6-disubstituted s-triazin-2-yl amino acid derivatives was prepared and characterized. Most of them showed antifungal activity against Candida albicans compared to clotrimazole (standard drug). Compounds bearing aniline derivatives, piperidine and glycine on the triazine core showed the highest inhibition zones at concentrations of 50, 100, 200, and 300 μg per disc. In addition, docking studies revealed that all the compounds accommodated well in the active site residues of N-myristoltransferase (NMT) and exhibited complementarity, which explains the observed antifungal activity. Interestingly, none of these compounds showed antibacterial activity.Deanship of Scientific Research at King Saud University, Saudi Arabia, research group no. (RGP-1441-234). National Research Foundation (NRF) (# 105892 and Blue Sky’s Research Programme # 120386).Peer reviewe