1.Serratia marcescens TF-1 for biodegradation of chlorobenzene contaminants in soil and its application in in-situ remediation of chemical industrial sites.
Fang GOU ; Yunchun SHI ; Hao CHEN ; Wenting FU ; Liangjie LI ; Zhilin XING ; Jiangfeng GUO
Chinese Journal of Biotechnology 2025;41(6):2483-2497
Chlorobenzene contaminants (CBs) pose a threat to the eco-environment, and functional strains hold considerable potential for the remediation of CB-contaminated sites. To deeply explore the application potential of functional bacteria in the in-situ bioremediation of CBs, this study focused on the biodegradation characteristics and degradation kinetics of CB and 1, 2-dichlorobenzene (1, 2-DCB) in soil by the isolated strain Serratia marcescens TF-1. Additionally, an in-situ remediation trial was conducted with this strain at a chemical industrial site. Batch serum bottle experiments showed that the degradation rate of CB at the concentrations ranging from 20 to 200 mg/L by TF-1 was 0.22-0.66 mol/(gcell·h), following the Haldane model, with the optimal concentration at 23.12 mg/L. The results from simulated soil degradation experiments indicated that the combined use of TF-1 and sodium succinate (SS) significantly enhanced the degradation of CBs, with the maximum degradation rate of CB reaching 0.104 d-1 and a half-life of 6.66 d. For 1, 2-DCB, the maximum degradation rate constant was 0.068 7 d-1, with a half-life of 10.087 d. The in-situ remediation results at the chemically contaminated site demonstrated that the introduction of bacterial inoculant and SS significantly improved the removal of CBs, achieving the removal rates of 84.2%-100% after 10 d. CB, 1, 4-dichlorobenzene (1, 4-DCB), and benzo[a]pyrene were completely removed. Microbial diversity analysis revealed that the in-situ remediation facilitated the colonization of TF-1 and the enrichment of indigenous nitrogen-fixing Azoarcus, which may have played a key role in the degradation process. This study provides a theoretical basis and practical experience for the in situ bioremediation of CBs-contaminated sites.
Chlorobenzenes/isolation & purification*
;
Biodegradation, Environmental
;
Soil Pollutants/isolation & purification*
;
Serratia marcescens/metabolism*
;
Industrial Waste
;
Soil Microbiology
2.Capillary gas chromatographic determination of dimethachlon residues in fresh tobacco leaves and cut-tobacco.
Hong-cheng LIU ; Qi-wan LI ; Li-bin TANG
Journal of Zhejiang University. Science. B 2007;8(4):272-276
Simple procedures for extraction and chromatographic determination of dimethachlon residues in fresh tobacco leaves and cut-tobacco are described. The determination was carried out by capillary gas chromatography (GC) with electron capture detection (ECD) and confirmed by GC-MS. The mean recoveries and relative standard deviation (RSD) were 93.2%~112.9% and 3.5%~6.7%, respectively at levels ranging from 0.01 to 0.1 mg/kg. The limit of determination was 0.001 mg/kg. Tobacco samples in routine check were successfully analyzed using the proposed method.
Chlorobenzenes
;
analysis
;
isolation & purification
;
Chromatography, Gas
;
methods
;
Plant Leaves
;
chemistry
;
Sensitivity and Specificity
;
Succinimides
;
analysis
;
isolation & purification
;
Tobacco
;
chemistry

Result Analysis
Print
Save
E-mail