ECO-FRIENLY SYNTHESIS OF GOLD NANOPARTICLES AND STUDY THEIR EFFECT WITH ANTIBIOTICS AGAINST ACINETOBACTER BAUMANNII

This study was aimed to produce AuNPs biologically using Klebsiella pneumoniae and study their synergistic effect with some antibiotics.Technologies of nanoparticles are quick and are employed in many applications in biomedicine. The potential of metallic nanoparticle as an anti-microbial agent is greatly investigated which considered as an alternative method to reduce the challenges of multi-drug resistance microbes. The present study discusses the novel approach to synthesize nanoparticles involving eco-friendly synthesis of gold nanoparticles using Klebsiella pneumoniae and study their effect as antimicrobial spectrum .Also study synergism effect of gold nanoparticles with antibiotic against Acinetobacter baumannii. These approaches are used to enhance antimicrobial efficacy of nanoparticles by modification of surfaces and to investigate activity of antibiotic delivery.

Synergism of Phage фPT1b and Antibiotics for Reducing Infection of Escherichia coli

Foodborne disease caused by Escherichia coli contamination is increasing every year. It also followed by elevating of drug-resistance of E. coli. Bacteriophage can be an alternative for therapy infection. This study aimed to determine synergism effect of bacteriophage ϕPT1b which has a high rate virulence to E. coli and phage-antibiotics (tetracycline and amoxicillin) synergy. The indigenous bacteria isolates were KR, MJ, KP, PT, PR. Five bacteriophages used namely ϕKR1b, ϕKR2, ϕPT1a, ϕPT1b, and ϕMJ1b. Virulence test was used to determine the ability of each phage in reducing E. coli. Treatment to examine synergism of phage ϕPT1b and antibiotics were P1: amoxicillin, P2: ϕPT1b, P3: ϕPT1b + Amx = 1:1, P4 : ϕPT1b + Amx = 2:1, P5: ϕPT1b + Amx = 1:2, P6 : tetracycline, P2: ϕPT1b, P7: ϕPT1b + Tet = 1:1, P8 : ϕPT1b + Tet = 2:1, and P9: ϕPT1b + Tet = 1:2. The virulence test showed that isolate ϕPT1a with 106 CFU/ml had the highest ability in reducing E. coli. While, the result of synergism test indicated that the synergism of bacteriophage and antibiotics differ significantly (P ≤ 0.05). The best ratios of synergism were 1:1 (ϕPT1b+tetracycline) and 2:1 (ϕPT1b+amoxicilline). In summarize, phage-antibiotic synergy (ϕPT1b with tetracycline/amoxicilline) can reduce the level of antibiotic resistance in isolated E. coli.

Cloning and characterization of an exocellulase and synergistic effect with recombinant endocellulase and beta-glucosidase from Bacillus subtilis 1AJ3

Background: Biomass lignocellulose provide abandon cellulosic material for bioenergy. The synergy effect of the cellulase system still needs more attention to make it more efficient. Exocellulase was less of studies in former studies, especially recombinant exocellulase from bacteria. Results: An exocellulase Cbh -A from strain B. subtilis 1AJ3 was cloned and expressed in E.coli BL21. By sequence analysis, Cbh -A contains two domains: FlgJ and SH3_8. Enzymatic properties of Cbh -A were characterized, and the maximum enzyme activity was gotten under the condition of pH 6.4 and 50℃. Moreover, the enzyme reached the highest enzyme activity and kept stable under 50℃ for 4 h. Ion metal Mn 2+ had an activating effect on Cbh -A, while Cu 2+ as well as chemical EDTA had inhibition effect. Cbh -A had widely substrates specification that it could hydrolyze β-1,3-1,4/β-1,3/β-1,4 glucan linkage, α-1,4 glucan linkage . When it took cooperation with recombinant endocellulase and β-glucosidase also from the strain B. subtilis 1AJ3, synergism effect was observed through DS (degree of synergism) value by hydrolyzing CMC-Na, Avicel, and filter paper. At the same time, the synergism effect was also examined in biomass lignocellulose by comparing the saccharification rate and DS value of each material. Conclusions: Cbh -A contained a FlgJ domain and first studied as an exocellulase cloned from B. subtilis 1AJ3. The biochemical, enzymatic properties, ion metal, and substrate specificity of Cbh -A were analyzed, and a special character of Cbh -A could keep maximum activity after pre-warm at 50℃ for 4h. Cbh-A had good synergy effect with endocellulase and β-glucosidase from the same strain in variety kind of cellulosic substrates, including simple and complex biomass cellulose. It laid a foundation of application by mixed cellulases via synergy effect, and supply new thought for the degradation of biomass lignocellulose.