[Impact of Anthraquinone-2-sulfonic Acid on the MO Decolorization, Hydrogen Production and Energy Creation During Anaerobic Fermentation of Klebsiella oxytocaGS-4-08 with Sucrose].

The effect of 0-0.5 mmol·L-1 anthraquinone-2-sulfonic acid on anaerobic fermentation of Klebsiella oxytocaGS-4-08 was analyzed. By comparing bio-hydrogen production, carbon source degradation, and degradation products, the optimal concentration of 0.1 mmol·L-1 was acquired. Under this concentration, Klebsiella oxytocaGS-4-08 could decolorize 100% methyl orange within 10 h, degrade 92% sucrose within 25 h, meanwhile produce 0.117 mol·mol-1 ethanol, 0.116 mol·mol-1 acetic acid, 2.25 mol·mol-1 hydrogen. Besides, the promoting mechanism of AQS on MO decolorization and hydrogen production by Klebsiella oxytocaGS-4-08 was analyzed by comparing the experimental results and the literatures. The electron transfer and energy conversion are analyzed during the bacterial degradation process by converting the substances into COD; the optimal electron yield was 87.98% and the optimal energy generation rate was 802 kJ·mol-1, and both were achieved under 0.1 mmol·L-1 of AQS. Using Klebsiella oxytoca GS-4-08, at least two types of biofuels could be produced via fermentation process, which showed prospects in future applications.

Decolorization characteristics of a newly isolated salt-tolerant Bacillus sp. strain and its application for azo dye-containing wastewater in immobilized form.

Strain CICC 23870 capable of decolorization of various azo dyes under high saline conditions was isolated from saline-alkali soil. The oxygen-insensitive azoreductase in crude extracts exhibited a wide substrate adaptively in the presence of NADH as a cofactor. The decolorization process by free cells followed first-order kinetics, with a high Methyl Orange (MO) tolerance concentration up to 100 mg l(-1) estimated by Haldane model. The average decolorization rate of free cell system was 26.30 mg g(-1) h(-1) at initial MO concentration of 32.7 mg l(-1). However, the values for the systems of immobilized cells (4 mm) in alginate, alginate and nano-TiO2, and alginate and powered activated carbon (PAC) were 6.83, 4.64, and 11.34 mg g(-1) h(-1), respectively. The effective diffusion factors in the tree different matrices were calculated by diffusion-based mathematic model. The diffusion step controls the overall decolorization rate, and the effective diffusion coefficients varied with internal structure of the bead matrices. The diffusion coefficients were increased from 4.98 × 10(-9) to 2.25 × 10(-8) cm(2) s(-1) when PAC was added, but decreased to 6.62 × 10(-10) cm(2) s(-1) when nano-TiO2 was added. The immobilized matrices could be reused for at least three cycles but with a decreased decolorization rate, possibly due to the breakage of beads at the end of each cycle, which led to the loss of immobilized bacteria.

Intracellular azo decolorization is coupled with aerobic respiration by a Klebsiella oxytoca strain.

Reduction of azo dye methyl red coupled with aerobic respiration by growing cultures of Klebsiella oxytoca GS-4-08 was investigated. In liquid media containing dye and 0.6 % glucose in a mineral salts base, 100 mg l(-1) of the dye are completely removed in 3 h under shaking conditions. The dye cannot be aerobically decolorized by strain GS-4-08 without extra carbon sources, indicating a co-metabolism process. Higher initial dye concentration prolonged the lag phase of the cell growth, but final cell concentrations of each batches reached a same level with range from 6.3 to 7.6 mg l(-1) after the dye adaption period. This strain showed stronger dye tolerance and decolorization ability than many reported strains. Furthermore, a new intracellular oxygen-insensitive azoreductase was isolated from this strain, and the specific activity of enzyme was 0.846 and 0.633 U mg(-1) protein in the presence of NADH and NADPH, respectively. N,N dimethyl-p-phenylenediamine and anthranilic acid were stoichiometrically released from MR dye, indicating the breakage of azo bonds accounts for the intracellular decolorization. Combining the characteristics of azoreductase, the stoichiometry of EMP, and TCA cycle, the electron transfer chain theory of aerobic respiration, and the possible mechanism of aerobic respiration coupled with azo reduction by K. oxytoca GS-4-08 are proposed. This study is expected to provide a sound theoretical basis for the development of the K. oxytoca strain in aerobic process for azo dye containing wastewaters.

A novel influenza A (H1N1) vaccine in various age groups.

BACKGROUND: There is an urgent need for a vaccine that is effective against the 2009 pandemic influenza A (H1N1) virus. METHODS: A split-virus, inactivated candidate vaccine against the 2009 H1N1 virus was manufactured, and we evaluated its safety and immunogenicity in a randomized clinical trial. Subjects were between 3 and 77 years of age, stratified into four age groups. The immunization schedule consisted of two vaccinations, 21 days apart. Subjects were injected with placebo or with vaccine, with or without alum adjuvant, at doses of 7.5 microg, 15 microg, or 30 microg. Serologic analysis was performed at baseline and on days 21 and 35. RESULTS: A total of 2200 subjects received one dose, and 2103 (95.6%) received the second dose, of vaccine or placebo. No severe adverse side effects associated with the vaccine were noted. In the nonadjuvanted-vaccine groups, injection-site or systemic reactions, most mild in nature, were noted in 5.5 to 15.9% of subjects. Among the subjects receiving 15 microg of nonadjuvanted vaccine, a hemagglutination-inhibition titer of 1:40 or more was achieved by day 21 in 74.5% of subjects between 3 and 11 years of age, 97.1% of subjects between 12 and 17 years, 97.1% of subjects between 18 and 60 years, and 79.1% of subjects 61 years of age or older; by day 35, the titer had been achieved in 98.1%, 100%, 97.1%, and 93.3% of subjects, respectively. The proportion with a titer of 1:40 or more was generally highest among the subjects receiving 30 microg of vaccine, with or without adjuvant. Vaccine without adjuvant was associated with fewer local reactions and greater immune responses than was vaccine with adjuvant. CONCLUSIONS: These data suggest that a single dose of 15 microg of hemagglutinin antigen without alum adjuvant induces a typically protective immune response in the majority of subjects between 12 and 60 years of age. Lesser immune responses were seen after a single dose of vaccine in younger and older subjects. (ClinicalTrials.gov number, NCT00975572).

Enhanced aerobic sludge granulation in sequencing batch reactor by Mg2+ augmentation.

Two sequencing batch reactors (SBRs) were concurrently operated to investigate the effect of Mg(2+) augmentation on aerobic granulation. Augmentation with 10mg/l Mg(2+) in R2 significantly decreased the sludge granulation (defined as that over 15% of granules were larger than 0.6mm) time from 32 days to 18 days, at the same time, the mean diameter of the granules in R2 was 2.9 mm after the granulation, which was consistently larger than that (1.8mm) in R1. Mg(2+)-fed granules were denser and more compact, showed better settling and had higher polysaccharide contents, but it did not result in a difference in microbial morphology. The results demonstrated that Mg(2+) enhanced the sludge granulation process in the sequencing batch reactor.

[Effects of environmental factors and denaturants on the specific absorption spectrum and fluorescence characters of B-phycoerythrin].

Effects of environmental factors and denaturants on the variation rules of the specific absorption spectrum and fluorescence emission intensity of B-phycoerythrin were systematically investigated in the present paper. The results showed that B-phycoerythrin was relatively stable under certain conditions: the pH range from 4. 5 to 9. 5, temperature range from 25 to 60 degrees C, and illumination intensity at 2 800 lx in 24 h. The specific absorption spectrum and fluorescence emission intensity of B-phycoerythrin changed slightly. The conformation of B-phycoerythrin changed remarkably with 0. 5 %-3% SDS or 0. 25 %-1% beta-mercaptoethanol, the fluorescence emission intensity declined greatly, and the specific absorption peaks disappeared. The fluorescence emission intensity declined, while the specific absorption spectrum did not change, but the peak intensity reduced slightly with 10%-70% acetonitrile or 2-8 mol x L(-1) urea. The possible reasons for the conformation changes of B-phycoerythrin with various environmental factors and different denaturants were briefly discussed.