To study the correlation of toxicity with biodegradability （BODT） in order to promote QSBR development and understand the degradation mechanism. Methods Toxicity of substituted phenols to river bacteria was determin...To study the correlation of toxicity with biodegradability （BODT） in order to promote QSBR development and understand the degradation mechanism. Methods Toxicity of substituted phenols to river bacteria was determined by the turbidities that were measured using a spectrophotometer （UV-190） at 530 nm against a blank control. The biodegradability of substituted phenols was expressed as BODT and the DO concentrations were determined by the iodometric titration method. Results The BODT and toxicity（log 1/IC50） of 12 substituted phenols to bacteria from the Songhua River were determined respectively. The correlation of biodegradability with toxicity was developed： BODT=8.21 （±2.22） pKa -32.44 （±8.28） log 1/IC50 ＋89.04 （±38.20）, n=12, R^2=0.791, R^2（adj）=0.745, SE=9.134, F=17.066, P=0.001. Conclusion The BODT of substituted phenols was influenced by their toxicity and the ionization constant pKa. The stronger the toxicity, the less readily the compound was degraded by river bacteria.展开更多
The roots of onion (Allium cepa) stand out for having cells with large size and small number of chromosomes.These characteristics make them useful in bioassays for the measurement of a variety of cytogenetic and morph...The roots of onion (Allium cepa) stand out for having cells with large size and small number of chromosomes.These characteristics make them useful in bioassays for the measurement of a variety of cytogenetic and morphological parameters , in which they can be used as toxicity indicators of the induction and formation of micronuclei and chromosomal aberrations.Based on this background , the potential genotoxic effect of phenol concentration on cells of A.ceparoots was investigated either in terms of induced aberrations or micronuclei formation.The results demonstrated that the higher the concentration of phenol , the higher the incidence of abnormalities , thus confirming the genotoxicity of this pollutant.展开更多
Thirty-two strains isolated from olive oil production plants were screened for their tolerance to the polyphenols and their ability to grow in olive oil mill wastewaters (OMW). An Ascomycete isolate that grew best on ...Thirty-two strains isolated from olive oil production plants were screened for their tolerance to the polyphenols and their ability to grow in olive oil mill wastewaters (OMW). An Ascomycete isolate that grew best on OMW was selected for further study to evaluate its effect on removal of organic pollutants, phenolic compounds and OMW toxicity. This strain was identified by DSMZ as Aspergillus niger van Tieghem. The growth of Aspergillus niger van Tieghem on stored OMW decreased pH and led to the reduction of phenolic compounds with a resultant discoloration of OMW and significant reduction of chemical oxygen demand (COD), in proportion to the dilution of OMW. The reduction of the COD, phenolics and color exceeded 50%. Tannase, the enzyme detected in the growth medium of Aspergillus niger van Tieghem was produced during primary metabolic growth. The maximal enzyme activity attaining 0.68 EU/ml was achieved in 3rd days of cultivation. The phytotoxicity of the stored OMW was reduced to about 40% after 4 days’ incubation with Aspergillus niger van Tieghem.展开更多
基金This research was supported by the Science Foundation of Education Ministry of China (No. 03058) and Science Foundation for YoungTeachers of Northeast Normal University (No. 20050503).
文摘To study the correlation of toxicity with biodegradability （BODT） in order to promote QSBR development and understand the degradation mechanism. Methods Toxicity of substituted phenols to river bacteria was determined by the turbidities that were measured using a spectrophotometer （UV-190） at 530 nm against a blank control. The biodegradability of substituted phenols was expressed as BODT and the DO concentrations were determined by the iodometric titration method. Results The BODT and toxicity（log 1/IC50） of 12 substituted phenols to bacteria from the Songhua River were determined respectively. The correlation of biodegradability with toxicity was developed： BODT=8.21 （±2.22） pKa -32.44 （±8.28） log 1/IC50 ＋89.04 （±38.20）, n=12, R^2=0.791, R^2（adj）=0.745, SE=9.134, F=17.066, P=0.001. Conclusion The BODT of substituted phenols was influenced by their toxicity and the ionization constant pKa. The stronger the toxicity, the less readily the compound was degraded by river bacteria.
文摘The roots of onion (Allium cepa) stand out for having cells with large size and small number of chromosomes.These characteristics make them useful in bioassays for the measurement of a variety of cytogenetic and morphological parameters , in which they can be used as toxicity indicators of the induction and formation of micronuclei and chromosomal aberrations.Based on this background , the potential genotoxic effect of phenol concentration on cells of A.ceparoots was investigated either in terms of induced aberrations or micronuclei formation.The results demonstrated that the higher the concentration of phenol , the higher the incidence of abnormalities , thus confirming the genotoxicity of this pollutant.
文摘Thirty-two strains isolated from olive oil production plants were screened for their tolerance to the polyphenols and their ability to grow in olive oil mill wastewaters (OMW). An Ascomycete isolate that grew best on OMW was selected for further study to evaluate its effect on removal of organic pollutants, phenolic compounds and OMW toxicity. This strain was identified by DSMZ as Aspergillus niger van Tieghem. The growth of Aspergillus niger van Tieghem on stored OMW decreased pH and led to the reduction of phenolic compounds with a resultant discoloration of OMW and significant reduction of chemical oxygen demand (COD), in proportion to the dilution of OMW. The reduction of the COD, phenolics and color exceeded 50%. Tannase, the enzyme detected in the growth medium of Aspergillus niger van Tieghem was produced during primary metabolic growth. The maximal enzyme activity attaining 0.68 EU/ml was achieved in 3rd days of cultivation. The phytotoxicity of the stored OMW was reduced to about 40% after 4 days’ incubation with Aspergillus niger van Tieghem.
