Volume Of Bacterial Suspension Research Articles

The Effect of Volume and Inoculation Method on the Development of Bacterial Panicle Blight Disease in Rice Plant

Bacterial panicle blight in rice plants caused by Burkholderia glumae. These bacteria interfere with the grain filling process so that the grain is not filled and can cause yield losses of up to 75% on pathogenic infested land. This study was conducted to determine the effect of B. glumae suspension volume and inoculation method on the development of bacterial panicle blight. The research was conducted on vegetative and generative rice plants using a factorial completely randomized design with the volume of bacterial suspension as the first factor and the inoculation method as the second factor. The results showed that the higher the volume of the B. glumae suspension inoculated, the higher the severity of bacterial panicle blight in rice plants. Both the inoculation and injection methods can cause the same disease severity. Besides, the severity of bacterial panicle blight in the generative phase is more severe than in the vegetative phase.Keywords: Burkholderia glumae, generative phase, vegetative phase

Few Layered Oxidized h-BN as Nanofiller of Cellulose-Based Paper with Superior Antibacterial Response and Enhanced Mechanical/Thermal Performance.

In this study, hexagonal boron nitride nanosheets enriched with hydroxyl groups (h-BN-OH) were successfully grafted on the surface of cellulose fibers after the simple and effective exfoliation and oxidation of bulk h-BN. OH groups of h-BN-OH and the ones presented on the surface of cellulose fibers interacted via hydrogen bonding. Both spectroscopic (FT-IR, XRD) and microscopic (TEM, SEM, and atomic force microscopy (AFM)) methods results proved the successful functionalization of the cellulose fibers with the nanomaterial. Modified cellulose fibers were used to prepare paper sheets samples with different concentrations of the nanomaterial (1 wt %, 2 wt %, and 3 wt %). All the samples were tested for the antibacterial properties via the colony forming unit method and exhibited good performance against both Gram-negative (E. coli) and Gram-positive (S. epidermidis) model bacteria. Additionally, the influence of the volume of working bacterial suspension on the antibacterial efficiency of the obtained materials was examined. The results showed significantly better antibacterial performance when the volume of bacterial suspension was reduced. Mechanical properties of the paper samples with and without nanofiller were also characterized. Tensile strength, tearing strength, and bursting strength of the paper samples containing only 2 wt % of the nanofiller were improved by 60%, 61%, and 118% in comparison to the control paper samples, respectively. Furthermore, the nanofiller improved the thermal properties of the composite paper—the heat release rate decreased by up to 11.6%. Therefore, the composite paper can be further explored in a wide range of antibacterial materials, such as packaging or paper coatings

Enhanced phenol degradation using an immobilized highly efficient degrading fungus on a new porous adsorption material

ABSTRACTA highly efficient phenol degradation fungus, named as WJ-1, is segregated from activated sludge and classified as the strain of Candida tropicalis. The phenol degradation performance of the strain WJ-1 and its immobilization on the porous adsorption material (PAM), are systemically studied. The degradation results show that the strain could use phenol as the sole carbon source below 2000 mg/L of the phenol concentration. In the 1000 mg/L phenol solution, phenol could be completely degraded using the strain during 56 h under the optimum phenol degradation conditions, as follows: pH of 7.0, temperature of 30°C, the volumes of bacterial suspension of 30 mL (cells concentration of 4.5 × 1010/mL), and shaking speed of 180 rev/min. Under these conditions, phenol can be entirely degraded by the immobilized strain on the surface of PAM during 44 h with the dosage of PAM 45 g/L.

Synthesis of a novel alginate-rubber joint immobilization strains H-1 and its application in removal of Pb (II) from aqueous solution

In this study, a novel alginate-rubber-strains immobilized beads (ARSIBs) was synthesized at the optimum conditions that the concentration of sodium alginate was 4%; the volume of bacterial suspension was 75%; the quality of rubber powder was 3.2%; the crosslinking time was 24 h by the orthogonal experiments. The optimum conditions for Pb (II) adsorption were 1.2% ARSIBs, 100 mg L-1 initial concentrations, pH 5 and 3 h contact time. The equilibrium data were well fitted by the Freundlich isotherm model. The biosorption process was nearly consistent with the pseudo-second-order model. Meanwhile, the biosorption mechanism could be that Pb (II) was adsorbed by the hydroxyl and carboxyl, finally precipitated with phosphate in the form of NaPb4(PO4)3, Pb5(PO4)3(OH) and Pb(H2PO4)2 based on the spectra of FTIR and XRD, respectively. In addition, the stability of ARSIBs was enhanced due to the addition to the rubber powder in the process of wastewater treatment.

Effect of Microwave Radiation on Survival of Some Bacterial Species

Firouzi, R., Shekarforoush, S.S. and Hajikhani, F. 2003. Effect of microwave radiation on survival of some bacterial species. J. Appl. Anim. Res., 24: 207–211. The bactericidal effect of microwave irradiation on different species of bacteria like Bacillus subtilis, Clostridium perfringens, E. coli, Salmonella typhimurium, Pseudomonas aeruginosa, Listeria monocytogenes type 4a, Staphylococcus aureus and Enterococcus faecalis has been studied. Two different volumes of bacterial suspension (50 and 100 ml) were used for colony count at successive time intervals. The decimal reduction time (D values in seconds) were 9 for B. subtilis, 9.5 for C. perfringens, 13 for E, coli, 10 for S. typhimurium, 6 for P. aeruginosa, 8.5 for L. monocytogenes, 8 for Staph, aureus and 7 for Ent. faecalis, for 50 ml suspensions of various bacteria, respectively. D values for 100 ml of bacterial suspensions were 25.5,10,14,13,7,16,15 and 10 seconds, respectively. Under different conditions with respect to duration and volume of bacterial suspensions, a useful effect of bacterial killing by microwave irradiation was noted. B. subtilis could be considered as an optimal indicator for the sterilizing effect of microwave.

Colony counts on strips of agar in tubes.

SUMMARY: For viable counting, 0.1 ml. volumes of bacterial suspension were incorporated in 1.5-2 ml. nutrient agar, which after mixing was allowed to solidify in an almost horizontal test-tube so as to produce a 3–4 in. agar strip. After incubation in the vertical position, the counts of the strips gave estimates of a bacterial population which did not differ significantly from that obtained from plates inoculated with 1 ml. quantities.