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Deng D.,Ocean University of China | Mei C.,Guangdong Institute of Microbiology | Mei C.,State Key Laboratory of Applied Microbiology Ministry Guangdong Province Jointly Breeding Base | Mai K.,Ocean University of China | And 3 more authors.
Aquaculture Research | Year: 2013

A 60 days feeding experiment was conducted to determine the effects of YK-6 (a yeast culture feed supplement) on growth and immune responses of white shrimp, Litopenaeus vannamei and aquaculture environment in commercial scale farms composed of nine ponds. Three treatments (control, Diet 1 and Diet 2) were designed to contain YK-6 levels of 0.0, 1.0 and 1.5 g kg-1 respectively. At the end of the test, the mean production of Diet 1 (0.649 ± 0.030 kg m-2) and Diet 2 (0.648 ± 0.033 kg m-2) were significantly higher than that of the control by 29.5% and 29.3% respectively. The feed conversion ratio decreased significantly by 12.3% (Diet 1) and 8.5% (Diet 2) compared with the control group respectively. The environmental indices indicate that the quality of water and pond sediment was improved. The endotoxin concentrations, the number of Vibrios and heterotrophic bacteria in the shrimp intestine of the treatment groups were significantly lower than that of the control, particularly in the later stage of the farming period. The YK-6 extended positive effects on growth, improved sediment quality, reduced endotoxin in shrimp intestine, and enhanced activities of lysozyme and phenoloxidase. © 2012 John Wiley & Sons Ltd.

Li J.,South China University of Technology | Li J.,Guangdong Institute of Microbiology | Li J.,Guangdong Open Laboratory of Applied Microbiology | Li J.,State Key Laboratory of Applied Microbiology Ministry Guangdong Province Jointly Breeding Base | And 10 more authors.
Applied Microbiology and Biotechnology | Year: 2012

Two identical biotrickling filters named BTFa and BTFb were run in parallel to examine their performances in removing hydrogen sulfide. BTFa was filled with ceramic granules, and BTFb was filled with volcanic rocks. The results showed that BTFb was more robust than BTFa under acidic conditions. At empty bed residence times (EBRTs) of 20 and 15 s, the removal efficiency of BTFa was close to 100%. At EBRTs of 10 and 5 s, the removal efficiency of BTFa slightly decreased. The removal efficiencies of BTFa decreased by different degrees at the end of each stage, dropping to 94%, 81%, 60%, and 71%, respectively. However, the H2S removal efficiency in BTFb consistently reached 99% throughout the experiment. Pyrosequencing analyses indicated that members of Thiomonas dominated in both BTFs, but the relative abundance of Acidithiobacillus was higher in BTFb than in BTFa. © 2011 Springer-Verlag.

Qiu M.,State Key Laboratory of Applied Microbiology Ministry Guangdong Province Jointly Breeding Base | Qiu M.,Guangdong Institute of Microbiology | Qiu M.,Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application | Qiu M.,Guangdong Open Laboratory of Applied Microbiology | And 23 more authors.
Biodegradation | Year: 2012

Polybrominated diphenyl ethers (PBDEs) are a class of widely used flame retardants that have been highly accumulated in sediments. It is reported that microorganisms play an important role in the reductive debromination of PBDEs in anaerobic sediments. However, little is known about the effects of electron donors on the microbial community structure and their debromination capacity in PBDE transformation. In this study, alternate carbon substrates were used as electron donors to enrich the PBDE-debrominating microbial consortia to evaluate the effects of electron donors on PBDE microbial debromination. Decabromodiphenyl ether (BDE-209) was found to be the dominant (more than 50%) PBDEs congener in all consortia, and the percentage of BDE-209 was deceased by 12% (methanol), 11% (ethanol), 8% (acetate), 9% (lactate), 5% (pyruvate), and 11% (no electron donors), while the relative abundances of most lesser-brominated PBDEs increased after 90-day incubation compared to the initial profile of PBDEs. Substantial shifts in the microbial community structure among different amendments were observed based on denaturing gradient gel electrophoresis results. Pseudomonas spp. were identified to be the predominant organisms and the abundances of Band R, which was associated with Pseudomonas sp. SCSWA09, was well correlated with the biodegradation rate of BDE-209. Finally, the microbial community structure was highly correlated with the concentration of deca-BDE, octa-BDE and total nitrogen. These results provide insights into in situ bioremediation of environments contaminated by PBDEs and our understanding of microbial ecology associated with PBDE-debromination. © 2011 Springer Science+Business Media B.V.

Ou F.-Z.,Guangdong Institute of Microbiology | Ou F.-Z.,Guangdong University of Technology | Ou F.-Z.,State Key Laboratory of Applied Microbiology Ministry Guangdong Province Jointly Breeding Base | Sun G.-P.,Guangdong Institute of Microbiology | And 3 more authors.
Huanjing Kexue/Environmental Science | Year: 2013

The object of this work was to evaluate the feasibility of calcium nitrate-regulatory agent for the stabilization of heavy metals in tidal sediments. The pilot-scale treatment was deployed in a section of the urban river in Ronggui, Foshan, which was heavily contaminated with Cu, Zn, Pb and Cr. For the remediation of the contaminated sediment, chemical speciation and stability of four elements were studied. The results indicated that: a)the percentage of four elements associated with reducible fraction and oxidizable fraction was decreased with the treatment of regulatory agent; b) the regulatory agent could effectively promote Cu, Zn, Pb, and Cr in sediment distributing in the residual fraction, which were increased by 4%, 20%, 21% and 23% after being treated by dosing regulatory agent for 22 days, with lower bioavailability in environment; c) the concentration of acid soluble fraction of Cu, Pb and Cr was increased except Zn. In general, the effect of stabilization for heavy metals Cu, Zn, Pb and Cr by regulatory agent is not ideal except Zn which has a certain effect, but the effect is not obvious.

Pan T.,South China University of Technology | Pan T.,Guangdong Institute of Microbiology | Pan T.,Guangdong Open Laboratory of Applied Microbiology | Pan T.,State Key Laboratory of Applied Microbiology Ministry Guangdong Province Jointly Breeding Base | And 12 more authors.
Separation Science and Technology (Philadelphia) | Year: 2013

A method for removing four triphenylmethane dyes from wastewater by cloud point extraction with the nonionic surfactant Triton X-114 (TX-114) was developed. The triphenylmethane dyes were crystal violet, ethyl violet, malachite green and brilliant green. The cloud point of TX-114 generally increased in the presence of any of the four dyes. In the cloud point system, these dyes were solubilized into a coacervate phase that left a color-free dilute phase. The extraction efficiency of the dyes increased with the temperature, TX-114 concentration, and salt (NaCl and CaCl2) concentration. More than 97% TX-114 in the dilute phase was recovered by adjusting the volume ratio of dichloromethane to the dilute phase. The Langmuir-type adsorption isotherm was used to describe the dye solubilization. The Langmuir constants m and n were calculated as functions of temperature. The results showed that the solubilization of the triphenylmethane dyes in the cloud point system was related to the partition coefficient and their molecular structures. © 2013 Copyright Taylor and Francis Group, LLC.

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