TY - JOUR
T1 - How Serratia marcescens HB-4 absorbs cadmium and its implication on phytoremediation
AU - Chen, Yakui
AU - Zhu, Qifa
AU - Dong, Xiangzhou
AU - Huang, Weiwei
AU - Du, Chenyu
AU - Lu, Diannan
PY - 2019/12/15
Y1 - 2019/12/15
N2 - A novel strain Serratia marcescens HB-4 with high Cadmium adsorption capacity was isolated from heavy metal contaminated soil in Hunan province, China. S. marcescens HB-4 reduced the concentration of Cd present in wastewater to less than 0.1 mg/L when the inlet stream contained no higher than 5.0 mg/L Cd. After treatment, wastewater meets Integrated Wastewater Discharge Standard of China (GB8978-1996). The naturally dead S. marcescens HB-4 still maintained over 80% of its Cd adsorption capacity. Scanning electron microscope (SEM), transmission electron microscope (TEM) and energy dispersive spectroscopy (EDS) results suggested that the mechanism of Cd adsorption can be explained as the synergy of extracellular adsorption, periplasm accumulation and intracellular absorption. The size of the accumulated Cd particular is at the nanometer scale, which can be washed out by EDTA without damaging cell integrity. SDS-polyacrylamide gel electrophoresis experiment showed that the heavy metal binding protein (especially Fe binding protein), transporter, amino acid and histidine periplasmic binding proteins and oxidoreductases were responsible for Cd removal. The pot experiment of S. marcescens HB-4 combined with Houttuynia cordata to detoxify Cd contaminated soil showed that the cadmium content in the aboveground and underground parts of Houttuynia cordata increased by 34.48% and 59.13% (w/w), respectively. The cadmium accumulation in Houttuynia cordata increased by 44.27% compared with the blank group which was not combined with S. marcescens HB-4. This work demonstrates that microbial synergistic phytoremediation has a significant potential to treat heavy metal contaminated soil.
AB - A novel strain Serratia marcescens HB-4 with high Cadmium adsorption capacity was isolated from heavy metal contaminated soil in Hunan province, China. S. marcescens HB-4 reduced the concentration of Cd present in wastewater to less than 0.1 mg/L when the inlet stream contained no higher than 5.0 mg/L Cd. After treatment, wastewater meets Integrated Wastewater Discharge Standard of China (GB8978-1996). The naturally dead S. marcescens HB-4 still maintained over 80% of its Cd adsorption capacity. Scanning electron microscope (SEM), transmission electron microscope (TEM) and energy dispersive spectroscopy (EDS) results suggested that the mechanism of Cd adsorption can be explained as the synergy of extracellular adsorption, periplasm accumulation and intracellular absorption. The size of the accumulated Cd particular is at the nanometer scale, which can be washed out by EDTA without damaging cell integrity. SDS-polyacrylamide gel electrophoresis experiment showed that the heavy metal binding protein (especially Fe binding protein), transporter, amino acid and histidine periplasmic binding proteins and oxidoreductases were responsible for Cd removal. The pot experiment of S. marcescens HB-4 combined with Houttuynia cordata to detoxify Cd contaminated soil showed that the cadmium content in the aboveground and underground parts of Houttuynia cordata increased by 34.48% and 59.13% (w/w), respectively. The cadmium accumulation in Houttuynia cordata increased by 44.27% compared with the blank group which was not combined with S. marcescens HB-4. This work demonstrates that microbial synergistic phytoremediation has a significant potential to treat heavy metal contaminated soil.
KW - Binding protein
KW - Bioremediation
KW - Extracellular adsorption
KW - Intracellular absorption
KW - Microorganism
KW - Periplasm accumulation
UR - http://www.scopus.com/inward/record.url?scp=85072773720&partnerID=8YFLogxK
U2 - 10.1016/j.ecoenv.2019.109723
DO - 10.1016/j.ecoenv.2019.109723
M3 - Article
AN - SCOPUS:85072773720
VL - 185
JO - Ecotoxicology and Environmental Safety
JF - Ecotoxicology and Environmental Safety
SN - 0147-6513
M1 - 109723
ER -