Bioremediation of Cd and carbendazim co-contaminated soil by Cd-hyperaccumulator Sedum alfredii associated with carbendazim-degrading bacterial strains

Abstract

The objective of this study was to develop a bioremediation strategy for cadmium (Cd) and carbendazim co-contaminated soil using a hyperaccumulator plant (Sedum alfredii) combined with carbendazim-degrading bacterial strains (Bacillus subtilis, Paracoccus sp., Flavobacterium and Pseudomonas sp.). A pot experiment was conducted under greenhouse conditions for 180 days with S. alfredii and/or carbendazim-degrading strains grown in soil artificially polluted with two levels of contaminants (low level, 1 mg kg(-1) Cd and 21 mg kg(-1) carbendazim; high level, 6 mg kg(-1) Cd and 117 mg kg(-1) carbendazim). Cd removal efficiencies were 32.3-35.1 % and 7.8-8.2 % for the low and high contaminant level, respectively. Inoculation with carbendazim-degrading bacterial strains significantly (P < 0.05) increased Cd removal efficiencies at the low level. The carbendazim removal efficiencies increased by 32.1-42.5 % by the association of S. alfredii with carbendazim-degrading bacterial strains, as compared to control, regardless of contaminant level. Cultivation with S. alfredii and inoculation of carbendazim-degrading bacterial strains increased soil microbial biomass, dehydrogenase activities and microbial diversities by 46.2-121.3 %, 64.2-143.4 %, and 2.4-24.7 %, respectively. Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analysis revealed that S. alfredii stimulated the activities of Flavobacteria and Bradyrhizobiaceae. The association of S. alfredii with carbendazim-degrading bacterial strains enhanced the degradation of carbendazim by changing microbial activity and community structure in the soil. The results demonstrated that association of S. alfredii with carbendazim-degrading bacterial strains is promising for remediation of Cd and carbendazim co-contaminated soil.

<b>Biodegradation of the fungicide carbendazim by bacteria from <i>Coriandrum sativum</i> L. rhizosphere

“…Several bacteria efficient in degrading MBC have been cited in the literature, such as Pseudomonas sp. (Xiao et al, 2013), Bacillus subtilis TL-171 (Salunkhe et al, 2014), and Brevibacillus borstelensis (Arya & Sharma, 2015). Salunkhe et al (2014) reported that four strains of B. subtilis individually degraded from 75.7 to 95.2% MBC in a concentration of 10 μg mL -1 after 15 days of incubation.…”

Remediation and Safe Production of cd Contaminated Soil Via Multiple Cropping HyperaccumulatorSolanum nigrum L. and Low Accumulation Chinese Cabbage

“…However, Sedumal fredii showed very high Cd removal rate under pot culture experiment conditions. In 180 days, Cd removal efficiencies were 32.3-35.1% and 7.8-8.2% in 1 mg kg −1 Cd and 6 mg kg −1 Cd soils (Xiao et al 2013). After more than 3 years' remediation for 4 contaminated soils in glasshouse, Li et al found that Cd concentrations in plant were decreased during repeated phytoextraction especially for acid soils.…”

Evidence of biodegradation of chlorpyrifos by a newly isolated heavy metal-tolerant bacterium Acinetobacter sp. strain MemCl4

“…Recently, Xiao et al (2012) have reported bioremediation of cadmium and carbendazim co-contaminated soil by a carbendazim degrading microbial consortium (Bacillus subtilis, Paracoccus sp., Flavobacterium and Pseudomonas) and hyperaccumultor plant (Sedum alfredii). Several microorganisms inhabiting soil (Rhodococcus erythropolis djl-11, Brevibacillus borstelensis) and spent mushroom substrate (Trichoderma sp.…”