A promising gram-negative bacterial strain for the biodegradation of aniline as the sole carbon, nitrogen and energy sources was successfully isolated and identified as Delftia sp. XYJ6. The optimal temperature and pH...A promising gram-negative bacterial strain for the biodegradation of aniline as the sole carbon, nitrogen and energy sources was successfully isolated and identified as Delftia sp. XYJ6. The optimal temperature and pH for both the growth of Delftia sp. XYJ6 and the biodegradation of aniline were 30°C and 7.0, respectively. Initial aniline of 2000 mg·L-1 could be completely removed by the strain at 22 h, which showed that Delftia sp. XYJ6 had a strong ability in the biodegradation of aniline. It indicated that aniline was firstly converted to catechol catalyzed by aniline dioxygenase as a first product, which was then further biodegraded to cis,cis-muconic acid catalyzed by the catechol 1,2-dioxygenase of Delftia sp. XYJ6 as a second product. Cis,cis-muconic acid could also be further biodegraded to other small compound again. The pathway for the biodegradation of aniline by Delftia sp. XYJ6 was not previously reported.展开更多
To get a sort of new scaffold material for soft tissue reconstruction,we have prepared XLHA-PNIPAAm and XLHA-MC injectable hydrogels through blending crosslinked HA(XLHA) and two temperature-sensitive materials differ...To get a sort of new scaffold material for soft tissue reconstruction,we have prepared XLHA-PNIPAAm and XLHA-MC injectable hydrogels through blending crosslinked HA(XLHA) and two temperature-sensitive materials differed in degradation poly(N-isopropylacrylamide)(PNIPAAm) and methylcellulose(MC),respectively.We tested the injectablility,enzymatic biodegradability,temperature-sensitivity,structure cytotoxicity and hemolysis of the two injectable hydrogels.Our research has successfully obtained the preparation condition of XLHA-PNIPAAm injectable hydrogel,and verified that adding non-degradable material PNIPAAm can postpone the degradation of HA more effectively than degradable material MC.PNIPAAm prepared with 5 kGy dose radiation,MBAAm/NIPAAm(M/M)=0.015,monomer concentration=3% produced XLHA-PNIPAAm with slowest enzymatic biodegradability.DSC results showed that temperature-sensitivity of the XLHA-PNIPAAm was more stable than that of XLHA-MC.Two composite hydrogels were qualified in cytotoxicity and hemolysis tests and the biocompatibility of XLHA-PNIPAAm hydrogel showed better than XLHA-MC hydrogel.展开更多
Biological treatment efficiency of six pharmaceutical compounds （acetazolamide, metronidazole, opipramol, piracetam, salicylamide and tinidazole） was evaluated using lab-scale Sequencing Batch Reactor （SBR）. Compa...Biological treatment efficiency of six pharmaceutical compounds （acetazolamide, metronidazole, opipramol, piracetam, salicylamide and tinidazole） was evaluated using lab-scale Sequencing Batch Reactor （SBR）. Comparative biological degradation processes of two types of activated sludge from municipal and pharmaceutical industry sewage treatment plants were examined. Three different organic loadings （0.05 g COD/g MLSS.d, 0.1 g COD/g MLSS.d and 0.2 g COD/g MLSS-d） and reaction time on the efficiency of Active Pharmaceutical Ingredient （API） decomposition were examined. Chemical oxygen demand, non-purgeable organic carbon as well as ammonium nitrogen contents were monitored by standard methods. Percentage of API decomposition was analysed by High Performance Liquid Chromatography （HPLC）. The overall API removal efficiency was strictly dependent on the type of activated sludge origin. The main biodegradation products were identified using HPLC-MS,1H NMR and 13C NMR methods as e.g. （{4-[3-（5H-dibenzo[b,f]azepin-5-yl]piperazin-l-yl}methanamine） and （2-amino-1,3,4-thiadiazol-5-sulfonamide） for opipramol and acetazolamide respectively.展开更多
基金Supported by the National Natural Science Foundation of China (20777008)the Education Committee of Beijing
文摘A promising gram-negative bacterial strain for the biodegradation of aniline as the sole carbon, nitrogen and energy sources was successfully isolated and identified as Delftia sp. XYJ6. The optimal temperature and pH for both the growth of Delftia sp. XYJ6 and the biodegradation of aniline were 30°C and 7.0, respectively. Initial aniline of 2000 mg·L-1 could be completely removed by the strain at 22 h, which showed that Delftia sp. XYJ6 had a strong ability in the biodegradation of aniline. It indicated that aniline was firstly converted to catechol catalyzed by aniline dioxygenase as a first product, which was then further biodegraded to cis,cis-muconic acid catalyzed by the catechol 1,2-dioxygenase of Delftia sp. XYJ6 as a second product. Cis,cis-muconic acid could also be further biodegraded to other small compound again. The pathway for the biodegradation of aniline by Delftia sp. XYJ6 was not previously reported.
基金The Nattional Key Scientific Program-Nanoscience and Nanotechnologygrant number:2009CB930000
文摘To get a sort of new scaffold material for soft tissue reconstruction,we have prepared XLHA-PNIPAAm and XLHA-MC injectable hydrogels through blending crosslinked HA(XLHA) and two temperature-sensitive materials differed in degradation poly(N-isopropylacrylamide)(PNIPAAm) and methylcellulose(MC),respectively.We tested the injectablility,enzymatic biodegradability,temperature-sensitivity,structure cytotoxicity and hemolysis of the two injectable hydrogels.Our research has successfully obtained the preparation condition of XLHA-PNIPAAm injectable hydrogel,and verified that adding non-degradable material PNIPAAm can postpone the degradation of HA more effectively than degradable material MC.PNIPAAm prepared with 5 kGy dose radiation,MBAAm/NIPAAm(M/M)=0.015,monomer concentration=3% produced XLHA-PNIPAAm with slowest enzymatic biodegradability.DSC results showed that temperature-sensitivity of the XLHA-PNIPAAm was more stable than that of XLHA-MC.Two composite hydrogels were qualified in cytotoxicity and hemolysis tests and the biocompatibility of XLHA-PNIPAAm hydrogel showed better than XLHA-MC hydrogel.
文摘Biological treatment efficiency of six pharmaceutical compounds （acetazolamide, metronidazole, opipramol, piracetam, salicylamide and tinidazole） was evaluated using lab-scale Sequencing Batch Reactor （SBR）. Comparative biological degradation processes of two types of activated sludge from municipal and pharmaceutical industry sewage treatment plants were examined. Three different organic loadings （0.05 g COD/g MLSS.d, 0.1 g COD/g MLSS.d and 0.2 g COD/g MLSS-d） and reaction time on the efficiency of Active Pharmaceutical Ingredient （API） decomposition were examined. Chemical oxygen demand, non-purgeable organic carbon as well as ammonium nitrogen contents were monitored by standard methods. Percentage of API decomposition was analysed by High Performance Liquid Chromatography （HPLC）. The overall API removal efficiency was strictly dependent on the type of activated sludge origin. The main biodegradation products were identified using HPLC-MS,1H NMR and 13C NMR methods as e.g. （{4-[3-（5H-dibenzo[b,f]azepin-5-yl]piperazin-l-yl}methanamine） and （2-amino-1,3,4-thiadiazol-5-sulfonamide） for opipramol and acetazolamide respectively.
