Variable metal resistance of P. putida CZ1 biofilms in different environments suggests its remediation application scope. (15th November 2021)

• Record Type: Journal Article
• Authors: Lin, Huirong; Chen, Guangcun; Zhao, Hongmei; Cao, Yuanqing
• Is Part Of: Journal of environmental management. Volume 298(2021)
• Publication Date: 2021-11-15
• Subjects: Accumulation -- Biofilms -- Bioremediation -- Metals -- Resistance; Environmental policy -- Periodicals; Environmental management -- Periodicals; Environment -- Periodicals; Ecology -- Periodicals; 363.705
• DOI: 10.1016/j.jenvman.2021.113458
• Languages: English
• ISSNs: 0301-4797

Abstract

Abstract: Pseudomonas putida is potentially used in the bioremediation of heavy metals (HMs). Its response to different HMs in different environments is still not fully understood. This study investigated resistance against 12 kinds of metals by P. putida CZ1 planktonic cells and its biofilm in LB and mineral medium (MM). P. putida CZ1 biofilms have high resistance and accumulation capacity for Cu 2+, Zn 2+, Pb 2+, Fe 3+, Mn 2+, Al 3+ and Ni 2+, but less resistance to Co 2+, Cd 2+, Cr2 O7 2−, Ag + and Hg 2+ . Biofilms were 2–8 times more resistant to Cu 2+ and Zn 2+ than planktonic cells. There was a strong correlation between the P content and the accumulation of Cu 2+, Zn 2+, Fe 3+, Mn 2+, Pb 2+, Ni 2+ and Al 3+ respectively. Confocal laser scanning microscopy (CLSM) combined with live/dead staining study found that cells in the biofilms can keep viable after 36 h under MIC of Cu 2+ or Zn 2+ both in LB and MM. When the metal concentration increased, cells can be killed gradually. For Cu 2+, Zn 2+, Fe 3+, Mn 2+, Pb 2+ and Ni 2+, higher resistance was found in MM (2–4 times higher) than in LB and higher accumulation of these metals were also found in MM. P. putida CZ1 biofilm cultured in MM with citric acid as carbon source had stronger resistance and accumulation ability to Cu 2+, Zn 2+, Pb 2+, Fe 3+, Mn 2+, and Ni 2+ . This suggested that P. putida CZ1 had greater remediation potential for these metals in organic acid rich environments. Graphical abstract: Image 1 Highlights: P. putida CZ1 biofilms have higher resistance for Cu 2+, Zn 2+, Pb 2+, Fe 3+, Mn 2+, Al 3+ and Ni 2+ than other tested metals. Cells in the biofilms can keep viable under MIC of Cu 2+ or Zn 2+ stress. Higher MICs and accumulation were found in MM than in LB. P. putida CZ1 had remediation potential in organic acid rich environments.