Arthrobacter sp. AG1菌株降解土壤中阿特拉津研究

在阿特拉津浓度为50mg/kg干土的黄棕壤、潮土和红壤接种1.5×106CFU/g干土的降解菌Arthrobacter sp. AG1,10天后土壤中的阿特拉津分别降解至1.5、6.6和10mg/kg干土。阿特拉津的降解速率受到土壤性质的影响,但AG1仍能在不满足其生长繁殖要求的pH值的土壤中有效降解酸性土壤中阿特拉津;土壤中水分含量对降解效果影响较大,>20%时降解效果较好;土壤低含水量和低pH值会导致AG1降解阿特拉津的活力下降。不同的接种量对降解效果有一定影响,但105～107CFU/g干土接种量的AG1都能有效发挥降解作用。AG1降解完土壤中的阿特拉津后,在土壤含水量分别为5%和15%的情况下能长期保持降解活性,对60天后第2次施入黄棕壤和潮土中的50mg/kg阿特拉津4天时降解效率在65%以上。

Biodegradation of Atrazine in soils by Arthrobacter sp. AG1

1.5×106 CFU/dry soil atrazine-degrading strain Arthrobacter sp. AG1 was inoculated into three different types of soils (yellow-brown soil, fluvo-aquic soil and red soil) with atrazine (AT) at the concentration of 50 mg/kg. AT decreased to 1.5, 6.6 and 10 mg/kg. respectively in the three kinds of soils by AG1 after 10 days. AG1 degraded AT efficiently in these soils and the degrading efficiency was affected by soil characteristics. AG1 could still degrade AT in acid soil, even when soil pH was lower than the lowest pH for its growth. After removing AT in soils, AG1 could remain its degrading ability for long term even if soil water content was adjusted to 5% and 15%. After 60 days, AG1 inoculated before could still degrade over 65% of the 50 mg/kg AT which was added to yellow-brown soil and fluvo-aquic soil secondary. Low soil water content and pH value were not suitable for AG1 survival and pesticide-biodegradation in soil. Degradation was affected by soil water content, the feasible water content for AG1 to degrade AT efficiently should be above 20%. Degradation was also affected by inoculation volume, however, 105 to107 CFU/g dry soil inoculation volume could degrade AT efficiency.