Viability and distribution of bacteria immobilized on Sawdust@silica: The removal mechanism of phenanthrene in soil
Viability and distribution of bacteria immobilized on Sawdust@silica: The removal mechanism of phenanthrene in soil
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锯末@二氧化硅上固定化细菌的活力和分布：土壤中菲的去除机制
DOI：
10.1016/j.ecoenv.2020.110649
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发表时间：
2020
影响因子：
6.8
通讯作者：
Sun Jianhui
中科院分区：
文献类型：
--
作者：
Li Jinghua;Ou Yiwen;Zhang Yanshi;Guo Shuli;Li Shaohua;Guo Chuling;Dang Zhi;Cao Zhiguo;Feng Jinglan;Sun Jianhui
固定化细胞（IC）已被广泛用于增强有机污染土壤的修复（例如，多环芳烃（PAHs）。一旦将IC添加到异质土壤中，降解热点立即在载体附近形成，使剩余的土壤缺乏降解细菌。因此，目前尚不清楚IC如何有效利用土壤中的多环芳烃。研究了SiO2-IC（Cells@Sawdust@SiO2）在土水比为1：2的泥浆体系中的活性以及接种IC和菲（Phe）的分布，探讨了IC对多环芳烃（PAHs）的去除机理.结果表明，SiO_2-IC保持了（i）良好的繁殖能力（通过土壤相和水相中的生长曲线显示），（ii）优异的稳定性，其通过土壤相与水相中的菌落形成单位的比率、殖民地数与DNA拷贝之间的差异以及通过FESEM观察到的生物材料的特征来鉴定，高代谢活性（48 h后，ICs对土壤中Phe的去除率大于95%）。最后，根据土壤和水相中苯丙氨酸和异硫氰酸酯的分布和相关性，提出了异硫氰酸酯有效利用土壤中苯丙氨酸的可能途径。吸附-降解过程占主导地位，即，在IC和载体吸附的Phe之间发生增强的降解。该研究为开发一种有效的多环芳烃污染土壤生物修复材料提供了新的思路。
Immobilized cells (ICs) have been widely used to enhance the remediation of organic-contaminated soil (e.g., polycyclic aromatic hydrocarbons, PAHs). Once ICs are added to the heterogeneous soil, degradation hotspots are immediately formed near the carrier, leaving the remaining soil lack of degrading bacteria. Therefore, it remains unclear how ICs efficiently utilize PAHs in soil. In this study, the viability of Silica-IC (Cells@Sawdust@Silica) and the distribution of inoculated ICs and phenanthrene (Phe) in a slurry system (soil to water ratio 1:2) were investigated to explore the removal mechanism of PAHs by the ICs. Results showed that the Silica-IC maintained (i) good reproductive ability (displayed by the growth curve in soil and water phase), (ii) excellent stability, which was identified by the ratio of colony forming units in the soil phase to the water phase, the difference between the colony number and the DNA copies, and characteristics of the biomaterial observed by the FESEM, and (iii) high metabolic activity (the removal percentages of Phe in soil by the ICs were more than 95% after 48 h). Finally, the possible pathways for the ICs to efficiently utilize Phe in soil are proposed based on the distribution and correlation of Phe and ICs between the soil and water phase. The adsorption-degradation process was dominant,i.e., the enhanced degradation occurred between the ICs and carrier-adsorbed Phe. This study provided new insights on developing a bio-material for efficient bio-remediation of PAHs-contaminated soil.