Enhanced degradation of pendimethalin by immobilized cells of Bacillus lehensis XJU.
Enhanced degradation of pendimethalin by immobilized cells of Bacillus lehensis XJU.
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DOI：
10.1007/s13205-015-0299-0
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发表时间：
2015-12
期刊：
影响因子：
2.8
通讯作者：
More SS
中科院分区：
文献类型：
--
作者：
More VS;Tallur PN;Niyonzima FN;More SS
从污染土壤中分离到一株能降解二甲戊乐灵的细菌，经16 S rRNA基因序列分析鉴定为Bacillus lehensis XJU。6-经鉴定，二甲戊乐灵和3，4-二甲基-2，6-二硝基苯胺是该菌降解二甲戊乐灵的代谢产物。研究了B自由悬浮细胞和固定化细胞对二甲戊乐灵的生物降解。还研究了在各种基质即琼脂、藻酸盐、聚丙烯酰胺和聚氨酯泡沫上的Lehensis。在琼脂和藻酸盐中的游离和固定化细胞的批次降解率几乎相同，而聚丙烯酰胺和PUF固定化细胞分别在96和72 h后降解93和100的0.1%二甲戊灵。在较高浓度下，自由悬浮细胞的降解率降低，而同样的固定化细胞在96 h内完全降解0.2%二甲戊灵。用聚氨酯泡沫固定化细胞重复分批降解，重复使用35个循环，而不失去0.1%二甲戊灵的降解能力。相比之下，琼脂，藻酸盐和聚丙烯酰胺固定的细胞可以重复使用15，18和25个循环，分别。当二甲戊乐灵浓度增加到0.2%时，固定化细胞可以重复使用，但二甲戊乐灵降解率下降。聚氨酯泡沫固定化细胞表现出更好的耐受pH值和温度的变化比自由悬浮细胞，可以保存3个月以上，而不会失去二甲戊乐灵降解能力。固定化降解二甲戊灵的细胞可能是一种理想的技术，用于完全降解环境中的除草剂。
A bacterium capable of degrading pendimethalin was isolated from the contaminated soil samples and identified as Bacillus lehensis XJU based on 16S rRNA gene sequence analysis. 6-Aminopendimethalin and 3,4-dimethyl 2,6-dinitroaniline were identified as the metabolites of pendimethalin degradation by the bacterium. The biodegradation of pendimethalin by freely suspended and the immobilized cells of B. lehensis on various matrices namely agar, alginate, polyacrylamide, and polyurethane foam was also investigated. The batch degradation rate was nearly the same for both free and immobilized cells in agar and alginate, whereas polyacrylamide- and PUF-immobilized cells degraded 93 and 100 of 0.1 % pendimethalin after 96 and 72 h, respectively. At higher concentration, the degradation rate of freely suspended cells decreased; whereas the same immobilized cells on polyurethane foam completely degraded 0.2 % pendimethalin within 96 h. The repeated batch degradation with the polyurethane foam-immobilized cells was reused for 35 cycles without losing the 0.1 % pendimethalin degrading ability. In contrast, agar-, alginate- and polyacrylamide-immobilized cells could be reused for 15, 18, and 25 cycles, respectively. When the pendimethalin concentration was increased to 0.2 %, the immobilized cells could be reused but the pendimethalin degradation rate was decreased. Polyurethane foam-immobilized cells exhibited better tolerance to pH and temperature alterations than freely suspended cells and could be stored for more than 3 months without losing pendimethalin degrading ability. The immobilization of cells capable of degrading pendimethalin may serve as an ideal technique for the complete degradation of the herbicide in the environment.