1
|
Wang X, Li Y, Zhang X, Chen X, Wang X, Yu D, Ge B. The extracellular polymeric substances (EPS) accumulation of Spirulina platensis responding to Cadmium (Cd 2+) exposure. JOURNAL OF HAZARDOUS MATERIALS 2024; 470:134244. [PMID: 38598879 DOI: 10.1016/j.jhazmat.2024.134244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 04/03/2024] [Accepted: 04/07/2024] [Indexed: 04/12/2024]
Abstract
Spirulina platensis can secrete extracellular polymeric substances (EPS) helping to protect damage from stress environment, such as cadmium (Cd2+) exposure. However, the responding mechanism of S. platensis and the secreted EPS to exposure of Cd2+ is still unclear. This research focuses on the effects of Cd2+ on the composition and structure of the EPS and the response mechanism of EPS secretion from S. platensis for Cd2+ exposure. S. platensis can produce 261.37 mg·g-1 EPS when exposing to 20 mg·L-1 CdCl2, which was 2.5 times higher than the control group. The S. platensis EPS with and without Cd2+ treatment presented similar and stable irregularly fibrous structure. The monosaccharides composition of EPS in Cd2+ treated group are similar with control group but with different monosaccharides molar ratios, especially for Rha, Gal, Glc and Glc-UA. And the Cd2+ treatment resulted in a remarkable decline of humic acid and fulvic acid content. The antioxidant ability of S. platensis EPS increased significantly when exposed to 20 mg·L-1 CdCl2, which could be helpful for S. platensis protecting damage from high concentration of Cd2+. The transcriptome analysis showed that sulfur related metabolic pathways were up-regulated significantly, which promoted the synthesis of sulfur-containing amino acids and the secretion of large amounts of EPS.
Collapse
Affiliation(s)
- Xiufeng Wang
- State Key Laboratory of Heavy Oil Processing and Center for Bioengineering and Biotechnology, China University of Petroleum (East China), Qingdao 266580, PR China
| | - Yuhui Li
- State Key Laboratory of Heavy Oil Processing and Center for Bioengineering and Biotechnology, China University of Petroleum (East China), Qingdao 266580, PR China
| | - Xiaojing Zhang
- State Key Laboratory of Heavy Oil Processing and Center for Bioengineering and Biotechnology, China University of Petroleum (East China), Qingdao 266580, PR China
| | - Xin Chen
- State Key Laboratory of Heavy Oil Processing and Center for Bioengineering and Biotechnology, China University of Petroleum (East China), Qingdao 266580, PR China
| | - Xin Wang
- State Key Laboratory of Heavy Oil Processing and Center for Bioengineering and Biotechnology, China University of Petroleum (East China), Qingdao 266580, PR China
| | - Daoyong Yu
- State Key Laboratory of Heavy Oil Processing and Center for Bioengineering and Biotechnology, China University of Petroleum (East China), Qingdao 266580, PR China
| | - Baosheng Ge
- State Key Laboratory of Heavy Oil Processing and Center for Bioengineering and Biotechnology, China University of Petroleum (East China), Qingdao 266580, PR China.
| |
Collapse
|
2
|
Yang W, Sun T, Sun Y. Adsorption mechanism of Cd 2+ on microbial inoculant and its potential for remediation Cd-polluted farmland soils. CHEMOSPHERE 2024; 352:141349. [PMID: 38307335 DOI: 10.1016/j.chemosphere.2024.141349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 01/29/2024] [Accepted: 01/30/2024] [Indexed: 02/04/2024]
Abstract
The adsorption characteristics and mechanism of Cd2+ on microbial inoculant (MI) mainly composed of Bacillus subtilis, Bacillus thuringiensis and Bacillus amyloliquefaciens, and its potential for remediation Cd polluted soils through batch adsorption and soil incubation experiments. It was found that the Freundlich isotherm model and the pseudo-second-order kinetics were more in line with the adsorption processes of Cd2+. The maximum adsorption capacity predicted by Langmuir isotherm model suggested that of MI was 57.38 mg g-1. Scanning electron microscopy and energy dispersive spectroscopy (SEM-EDS) images exhibited the surface structure of MI was damaged to varying degrees after adsorption, and Cd element was distributed on the surface of MI through ion exchange. X-ray diffraction (XRD) results showed that CdCO3 was formed on the surface of MI. Moreover, the functional groups (-OH, C-H, and -NH) involved in the adsorption of Cd2+ through fourier transform infrared spectroscopy (FTIR). After applying MI to Cd-contaminated soil, it was found that soil pH, conductivity (EC) and soil organic matter (SOM) increased by 0.84 %-2.43 %, 31.6 %-241.48 %, and 8.11 %-24.1 %, respectively, when compared with the control treatments. The content of DTPA-Cd in the soils was significantly (P < 0.05) reduced by 15.48 %-29.68 % in contrast with CK, and the Cd speciation was transformed into a more stable residual fraction. The activities of urease, phosphatase and sucrose were increased by 3.5 %-45.18 %, 57.00 %-134.18 % and 52.51 %-70.52 %, respectively, compared with CK. Therefore, MI could be used as an ecofriendly and sustainable material for bioremediation of Cd-contaminated soils.
Collapse
Affiliation(s)
- Wenhao Yang
- Key Laboratory of Original Agro-Environmental Pollution Prevention and Control, Ministry of Agriculture and Rural Affairs (MARA)/Tianjin Key Laboratory of Agro-Environment and Agro-Product Safety, Agro-Environmental Protection Institute, MARA, Tianjin, 300191, China; College of Resources and Environment, Northeast Agricultural University, Harbin, 150030, China
| | - Tong Sun
- College of Resources and Environment, Northeast Agricultural University, Harbin, 150030, China
| | - Yuebing Sun
- Key Laboratory of Original Agro-Environmental Pollution Prevention and Control, Ministry of Agriculture and Rural Affairs (MARA)/Tianjin Key Laboratory of Agro-Environment and Agro-Product Safety, Agro-Environmental Protection Institute, MARA, Tianjin, 300191, China; College of Resources and Environment, Northeast Agricultural University, Harbin, 150030, China.
| |
Collapse
|
3
|
Chen Y, Li S, Chen X, Li Y, Yan C, Wang C, Wang Y, Xu H. Enhanced Cd activation by Coprinus comatus endophyte Bacillus thuringiensis and the molecular mechanism. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 342:123052. [PMID: 38040187 DOI: 10.1016/j.envpol.2023.123052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 11/21/2023] [Accepted: 11/25/2023] [Indexed: 12/03/2023]
Abstract
Fungal endophytes not only tolerate and activate Cd in soil but also promote host growth, yet its Cd activation capacity and mechanism remain unrevealed. Our previous study isolated a robust endophyte Bacillus thuringiensis L1 from Coprinus comatus fruiting body with splendid Cd resistance and activation abilities under laboratory conditions. In this study, those peculiarities were investigated in the actual soil environment. L1 could significantly increase the soil bioavailable Cd content and effectively compensate for alkali-hydro nitrogen losses and microbial inhibition caused by Cd. Furthermore, L1 inoculation improved the soil's bacterial community structure and increased the relative abundance of Cd-resistant bacteria, such as Actinobacteria, Chloroflexi, Acidobacter, and Firmicutes, closely associated with the soil enzyme activity shift. The genome sequencing analysis revealed the presence of genes related to growth promotion, resistance to Cd stress, and Cd activation, which were significantly up-regulated under Cd stress. Notably, L1 mainly activates Cd in soil by secreting citric acid, succinic acid, siderophore, and soluble phosphorus substances to chelate with Cd or dissolve bounded Cd. Meanwhile, the metal-responsive transcription repressor (CadC) and the Cd-translocating protein P-type ATPase (CadA) can help the L1 to suppress the toxicity of Cd. Those results help to unveil the possible mechanism of L1 in Cd-contaminated soil remediation, providing a clear strategy for Cd bio-extraction from soil.
Collapse
Affiliation(s)
- Yahui Chen
- Key Laboratory of Bio-resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, Sichuan, PR China.
| | - Shiyao Li
- Key Laboratory of Bio-resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, Sichuan, PR China
| | - Xianghan Chen
- Key Laboratory of Bio-resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, Sichuan, PR China
| | - Yongyun Li
- Key Laboratory of Bio-resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, Sichuan, PR China
| | - Chaoqun Yan
- Key Laboratory of Bio-resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, Sichuan, PR China
| | - Can Wang
- College of Life Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, Sichuan, PR China
| | - Ying Wang
- College of Life Sciences, Sichuan University, Chengdu, 610065, Sichuan, PR China
| | - Heng Xu
- Key Laboratory of Bio-resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, Sichuan, PR China; Key Laboratory of Environment Protection, Soil Ecological Protection and Pollution Control, Sichuan University & Department of Ecology and Environment of Sichuan, Chengdu, 610065, Sichuan, PR China.
| |
Collapse
|
4
|
Kaszecki E, Palberg D, Grant M, Griffin S, Dhanjal C, Capperauld M, Emery RJN, Saville BJ. Euglena mutabilis exists in a FAB consortium with microbes that enhance cadmium tolerance. Int Microbiol 2024:10.1007/s10123-023-00474-7. [PMID: 38167969 DOI: 10.1007/s10123-023-00474-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 11/29/2023] [Accepted: 12/15/2023] [Indexed: 01/05/2024]
Abstract
BACKGROUND Synthetic algal-fungal and algal-bacterial cultures have been investigated as a means to enhance the technological applications of the algae. This inclusion of other microbes has enhanced growth and improved stress tolerance of the algal culture. The goal of the current study was to investigate natural microbial consortia to gain an understanding of the occurrence and benefits of these associations in nature. The photosynthetic protist Euglena mutabilis is often found in association with other microbes in acidic environments with high heavy metal (HM) concentrations. This may suggest that microbial interactions are essential for the protist's ability to tolerate these extreme environments. Our study assessed the Cd tolerance of a natural fungal-algal-bacterial (FAB) association whereby the algae is E. mutabilis. RESULTS This study provides the first assessment of antibiotic and antimycotic agents on an E. mutabilis culture. The results indicate that antibiotic and antimycotic applications significantly decreased the viability of E. mutabilis cells when they were also exposed to Cd. Similar antibiotic treatments of E. gracilis cultures had variable or non-significant impacts on Cd tolerance. E. gracilis also recovered better after pre-treatment with antibiotics and Cd than did E. mutabilis. The recoveries were assessed by heterotrophic growth without antibiotics or Cd. In contrast, both Euglena species displayed increased chlorophyll production upon Cd exposure. PacBio full-length amplicon sequencing and targeted Sanger sequencing identified the microbial species present in the E. mutabilis culture to be the fungus Talaromyces sp. and the bacterium Acidiphilium acidophilum. CONCLUSION This study uncovers a possible fungal, algal, and bacterial relationship, what we refer to as a FAB consortium. The members of this consortium interact to enhance the response to Cd exposure. This results in a E. mutabilis culture that has a higher tolerance to Cd than the axenic E. gracilis. The description of this interaction provides a basis for explore the benefits of natural interactions. This will provide knowledge and direction for use when creating or maintaining FAB interactions for biotechnological purposes, including bioremediation.
Collapse
Affiliation(s)
- Emma Kaszecki
- Environmental and Life Science Graduate Program, Trent University, Peterborough, ON, Canada
| | - Daniel Palberg
- Environmental and Life Science Graduate Program, Trent University, Peterborough, ON, Canada
| | - Mikaella Grant
- Environmental and Life Science Graduate Program, Trent University, Peterborough, ON, Canada
| | - Sarah Griffin
- Forensic Science Department, Trent University, Peterborough, ON, Canada
| | - Chetan Dhanjal
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA, USA
| | | | - R J Neil Emery
- Environmental and Life Science Graduate Program, Trent University, Peterborough, ON, Canada
- Department of Biology, Trent University, Peterborough, ON, Canada
| | - Barry J Saville
- Environmental and Life Science Graduate Program, Trent University, Peterborough, ON, Canada.
- Forensic Science Department, Trent University, Peterborough, ON, Canada.
| |
Collapse
|