The Cd-tolerant and sodium alginate(SA)-synthesizing Pseudomonas putida XMS-1was characterized for Cd immobilization in solution.Additionally,the XMS-1 mutant constructed by deleting SA-synthesizing regulatory gene al...The Cd-tolerant and sodium alginate(SA)-synthesizing Pseudomonas putida XMS-1was characterized for Cd immobilization in solution.Additionally,the XMS-1 mutant constructed by deleting SA-synthesizing regulatory gene algB(△algB)were characterized for their roles in Cd uptake in Chinese chive in the Cd-contaminated soil.Between 12 and 48 h of incubation,the XMS-1△algBmutant significantly reduced solution Cd concentrations by 81%compared with the control but increased the Cd concentrations by 36%compared with XMS-1.After 48 h of incubation,the XMS-1△algB mutant significantly increased the Cd concentration by 36%and decreased the expolysaccharide(EPS)and SA concentrations by 30%-32%and cell surface-adsorbed Cd content by 24%in the Cd-containing medium,compared with XMS-1.The XMS-1△algB mutant significantly increased the root and leaf Cd contents of Chinese chive by 15%-50%and exchangeable Cd content by 17%and decreased the Fe-Mn oxideand organic matter-bound Cd contents by 17%-23%,compared with XMS-1.Furthermore,the XMS-1△algBmutant significantly decreased the EPS content by 33%,copies of algD gene involved in EPS production by 7.7-fold,and the interactions between the amino,hydroxyl,and carbonyl groups and Cd in the Cd-contaminated soil,compared with XMS-1.These results suggested that algB promoted XMS-1-mediated Cd-stabilizing related gene abundance and interactions between soil and Cd and decreased Cd uptake in Chinese chive.These findings may provide an effective and eco-friendly way using SA-producing bacteria for safe production of vegetables in the Cd-polluted soil.展开更多
基金supported by the National Natural Science Foundation of China(No.41977199).
文摘The Cd-tolerant and sodium alginate(SA)-synthesizing Pseudomonas putida XMS-1was characterized for Cd immobilization in solution.Additionally,the XMS-1 mutant constructed by deleting SA-synthesizing regulatory gene algB(△algB)were characterized for their roles in Cd uptake in Chinese chive in the Cd-contaminated soil.Between 12 and 48 h of incubation,the XMS-1△algBmutant significantly reduced solution Cd concentrations by 81%compared with the control but increased the Cd concentrations by 36%compared with XMS-1.After 48 h of incubation,the XMS-1△algB mutant significantly increased the Cd concentration by 36%and decreased the expolysaccharide(EPS)and SA concentrations by 30%-32%and cell surface-adsorbed Cd content by 24%in the Cd-containing medium,compared with XMS-1.The XMS-1△algB mutant significantly increased the root and leaf Cd contents of Chinese chive by 15%-50%and exchangeable Cd content by 17%and decreased the Fe-Mn oxideand organic matter-bound Cd contents by 17%-23%,compared with XMS-1.Furthermore,the XMS-1△algBmutant significantly decreased the EPS content by 33%,copies of algD gene involved in EPS production by 7.7-fold,and the interactions between the amino,hydroxyl,and carbonyl groups and Cd in the Cd-contaminated soil,compared with XMS-1.These results suggested that algB promoted XMS-1-mediated Cd-stabilizing related gene abundance and interactions between soil and Cd and decreased Cd uptake in Chinese chive.These findings may provide an effective and eco-friendly way using SA-producing bacteria for safe production of vegetables in the Cd-polluted soil.
