Growth inhibition of bacterial pathogens by photo-catalyst process of nano-alloys FeCuNi doped TiO2 under ultraviolet irradiation.

This study reports the application of FeCuNi nano-alloy doped TiO2 synthesized via the sol-gel method as an antibacterial with a sterilization rate greater than 95% under ultra-violet (UV) irradiation. The performance was characterized using X-ray diffraction (XRD), thermal analysis (TG-DTA), scanning electron microscope (SEM-EDX), and transmission electron microscope (TEM). The results showed that the sterilization process of FeCuNi-TiO2 in cell suspension of Escherichia coli, Staphylococcus aureus and Bacillus subtilis increased the effectiveness of UV irradiation at wavelength (λ) ≥ 385 nm after 120 min. The optimum growth inhibition of FeCuNi-TiO2 was observed in the concentrations 1.5 g/L of E. coli, 1.5 g/L of S. aureus and 2.0 g/L of B. subtilis. The highest antimicrobial efficiency of FeCuNi-TiO2 powder was provided by a particle size of 16.8 nm, surface area of 70.98 m2/g. The increased antimicrobial activity in multiplied-three doped ions was related to the increase of illumination energy of UV absorption in the photo-catalyst process. The inhibition mechanism reaction of the three species of bacteria cell affects the lipid peroxidation process at the microbe cell's wall. This was indicated by the formation of malondialdehyde (MDA). Lipid oxidation was based on the reaction of 2-thiobarbituric acid (TBARS) as an indicator of primary and secondary oxidation.

Enzyme Activity of Cellulolytic Bacteria from Biological Education and Research Forest Floor Andalas University.

<b>Background and Objective:</b> The composition of the waste consists mostly of plant biomass. Cellulose is the largest component of plant biomass and cellulolytic bacteria are needed to degrade it. This study aimed to determine enzyme activity possessed by bacterial isolates from Biological Education and Research Forest floor Andalas University. <b>Materials and Methods:</b> The isolation stage was carried out with NA (Nutrient agar) medium, Screening with CMC (Carboxymethyl Cellulose) medium with congo red dye and enzyme activity testing was carried out using the Nelson-Somogyi method. <b>Results:</b> We found 16 bacterial isolates obtained from Biological Education and Research Forest Floor Andalas University, 10 of them were positive for cellulolytic bacteria with the highest cellulolytic index value of 2.59 on FFB 2 isolates. <b>Conclusion:</b> The bacterial isolate with the best enzyme activity value was FFB 2 isolate 0.166 U mL¹ for 72 hrs.

Pseudomonas aeruginosa antibacterial textile cotton fiber construction based on ZnO-TiO2 nanorods template.

An alternative method of synthesizing ZnO-TiO2 nanorods is through route precipitation and sintering at 600 °C. In this study, the introduction of Ti into Zn in the molar ratio Ti:Zn (1:3) produced a composite ZnO-Low TiO2 (ZnO-LTiO2) while 1:1 produced ZnO-High TiO2 (ZnO-HTiO2). The effect of the Ti introduced on the anti-bacterial properties of ZnO-TiO2 nanorods was investigated with the product structure characterized by XRD and the optimal intensity at 2θ: 31.72°, 34.37°, 36.19° showed a Wurzite structure and a crystal size of 35.8-41.5 nm. The average pore diameters for ZnO-LTiO2 and ZnO-HTiO2 were around 5.159 nm and 6.828 nm while the surface areas were 15.692 m2/g and 15.421 m2/g respectively. The anti-bacterial textile fiber construction was prepared using dip-spin coating with the application of an adipic acid crosslinker for 6 h and stable coating up to 10 times washing. The improvement of Pseudomonas a eruginosa (Pa) antibacterial properties in the textiles with coating had an inhibition zone of 20.5-25.0 mm and 16.2 mm without the coating. The elements of the cotton fiber construction include C at 54.60%, O at 40.89%, Ti at 0.81% and Zn at 2.60% while the TG-DTA analysis conducted showed an increase in the heat stability of the textile fibers to a temperature of 400°C, after which the textiles were modified by coating ZnO-TiO2 nanorods. The findings of this research could be successfully applied to improve the antibacterial properties of textiles.