论文部分内容阅读
采用常规土壤酶活力测定方法、平板菌落计数法以及PCR-DGGE技术,分析头孢噻肟污染对土壤呼吸作用、部分酶活性、细菌数量以及细菌多样性的短期影响。结果表明:①头孢噻肟明显刺激处理后1～14d土壤呼吸强度,处理21d后刺激作用消失;头孢噻肟明显提高处理后1、18d土壤脲酶活性,处理后3、7d抑制作用明显;不同浓度头孢噻肟处理初期,土壤过氧化氢酶活力均受到抑制,随着培养时间的延长抑制率下降,并且低、中浓度头孢噻肟处理分别在处理后3、7d开始表现出对过氧化氢酶一定程度的刺激作用。②培养1～3d,各处理对土壤细菌数量具有一定的刺激作用,7d后中、高浓度处理对土壤细菌有一定抑制作用,而18d后各浓度处理土壤细菌数量基本恢复到对照水平。③采用Quantity One 4.6(Bio-Rad)软件,对PCR-DGGE图谱中各处理1、18d条带进行分析,发现头孢噻肟处理对样品可检测条带数没有影响,但对处理初期细菌优势种群丰度产生影响,此后逐渐恢复到对照水平。总之,头孢噻肟污染对供试土壤微生物活性、细菌数量以及优势种群的丰度具有不同程度的短期影响,但随着时间的延长,影响逐渐消失。
The effects of cefotioxime on soil respiration, partial enzyme activities, bacterial counts and bacterial diversity were analyzed using routine soil enzyme assays, plate colony counting and PCR-DGGE techniques. The results showed that: (1) after 1 ~ 14 days, cefotaxime obviously stimulated soil respiration, and disappeared after 21 days of treatment; while cefotaxime significantly increased soil urease activity at 1 and 18 days after treatment, with significant inhibition at 3 and 7 days after treatment; At the initial stage of cefotaxime treatment, the activities of soil catalase were inhibited, the inhibition rate decreased with the prolongation of culture time, and the treatment of low and medium concentrations of cefotaxime showed catalase A certain degree of stimulation. ② After culturing for 1 ~ 3 days, the treatments had a certain stimulation effect on the quantity of soil bacteria. After 7 days, medium and high concentration treatments had certain inhibition effect on soil bacteria, and the quantity of soil bacteria in each concentration treatment returned to the control level after 18 days. (3) Quantity One 4.6 (Bio-Rad) software was used to analyze the bands of PCR-DGGE for 1 and 18 days. It was found that cefotaxime treatment had no effect on the number of detectable bands in the samples, Abundance impact, then gradually returned to the control level. In conclusion, cefotaxim had short-term effects on soil microbial activity, bacterial population and the abundance of dominant species, but the influence disappeared with the extension of time.