Abstract

In this study, we sought to compose consortia of plant growth-promoting (PGP) and trace element tolerant bacteria, to improve plant growth and inhibit uptake and translocation of trace elements, eventually allowing the cultivation of profitmaking crops on trace elements polluted soils, reducing the risks of entrance of these elements into the food chain. Sunflower (Helianthus annuus L.) was grown on two polluted military soils (MS1 and MS2) in greenhouse microcosms and inoculated with three different bacterial consortia (C1, C2, C3). Growth and physiological status of the plants were unaffected during the experiment with the inoculation. After 2 months, plants were harvested. Consortium C2 and C3 decreased Pb shoot bioaccumulation by respectively 80–85% when plants were grown in the MS1 and even to concentrations below detection limit in plants grown in MS2. Differences in uptake and (sub)cellular localization of Pb and Cd in selected bacterial isolates were investigated in vitro by TEM-EDX. Pb absorption was observed by Bacillus wiedmanni ST29 and Bacillus paramycoides ST9 cultures. While adsorption at the bacterial cell wall was observed by Bacillus paramycoides ST9 and retention in the extracellular matrix by Cellulosimicrobium cellulans ST54.

摘要

在这项研究中，我们寻求组成植物促生菌 (PGP) 和微量元素耐受细菌的联合体，以改善植物生长并抑制微量元素的吸收和转运，最终允许在微量元素污染的土壤上种植盈利作物，减少这些元素进入食物链的风险。向日葵 ( Helianthus annuus L. ) 在温室缩影中的两种受污染的军用土壤 (MS1 和 MS2) 上生长，并接种了三种不同的细菌聚生体 (C1、C2、C3)。在接种实验期间，植物的生长和生理状态不受影响。2 之后 个月，植物被收获。当植物在 MS1 中生长时，C2 和 C3 联合体使 Pb 枝条的生物积累分别降低了 80-85%，甚至在 MS2 中生长的植物中铅的浓度低于检测限。通过 TEM-EDX在体外研究了选定细菌分离物中 Pb 和 Cd 的摄取和（亚）细胞定位的差异。Bacillus wiedmanni ST29 和Bacillus paramycoides ST9 培养物观察到 Pb 吸收。副蕈状芽孢杆菌ST9观察到细菌细胞壁的吸附，Cellulosimicrobium cellulans ST54观察到细胞外基质的保留。