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Wang Z, Zhang Y, Chen Y, Han F, Shi Y, Pan S, Li Z. Competition of Cd(II) and Pb(II) on the bacterial cells: a new insight from bioaccumulation based on NanoSIMS imaging. Appl Environ Microbiol 2024; 90:e0145323. [PMID: 38224623 PMCID: PMC10880600 DOI: 10.1128/aem.01453-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 12/01/2023] [Indexed: 01/17/2024] Open
Abstract
Polymetallic exposure causes complex toxicity to microorganisms. In this study, we investigated the responses of Escherichia coli under co-existence of cadmium (Cd) and lead (Pb), primarily based on biochemical analysis and RNA sequencing. Cd completely inhibited bacterial growth at a concentration of 2.41 mmol/L, with its removal rate as low as <10%. In contrast, the Pb removal rate was >95% under equimolar sole Pb stress. In addition, the Raman analysis confirmed the loss of proteins for the bacterial cells. Under the co-existence of Cd and Pb, the Cd toxicity to E. coli was alleviated. Meanwhile, the biosorption of Pb cations was more intense during the competitive sorption with Cd. Transmission electron microscopy images showed that a few cells were elongated during incubation, i.e., the average cellular length increased from 1.535 ± 0.407 to 1.845 ± 0.620 µm. Moreover, NanoSIMS imaging showed that the intracellular distribution of Cd and Pb was coupled with sulfur. Genes regulating sulfate transporter were also upregulated to promote sulfate assimilation. Then, the subsequent production of biogenic sulfide and sulfur-containing amino acids was enhanced. Although this strategy based on S enrichment could resist the polymetallic stress, not all related genes were induced to upregulate under sole Cd stress. Therefore, the S metabolism might remodel the microbial resistance to variable occurrence of heavy metals. Furthermore, the competitive sorption (in contrast to sole Cd stress) could prevent microbial cells from strong Cd toxicity.IMPORTANCEMicrobial tolerance and resistance to heavy metals have been widely studied under stress of single metals. However, the polymetallic exposure seems to prevail in the environment. Though microbial resistance can alleviate the effects of exogenous stress, the taxonomic or functional response to polymetallic exposure is still not fully understood. We determined the strong cytotoxicity of cadmium (Cd) on growth, and cell elongation would be driven by Cd stress. The addition of appropriate lead (Pb) showed a stimulating effect on microbial bioactivity. Meanwhile, the biosorption of Pb was more intense during co-existence of Pb and Cd. Our work also revealed the spatial coupling of intracellular S and Cd/Pb. In particular, the S assimilation was promoted by Pb stress. This work elucidated the microbial responses to polymetallic exposure and may provide new insights into the antagonistic function during metal stresses.
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Affiliation(s)
- Zhijun Wang
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, China
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, Guizhou, China.
| | - Ying Zhang
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Yunhui Chen
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Feiyu Han
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Yixiao Shi
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Shang Pan
- College of Agro-grassland Sciences, Nanjing Agricultural University, Nanjing, China
| | - Zhen Li
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, China
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, Guizhou, China.
- Key Laboratory of Eco-geochemistry, Ministry of Natural Resources, Beijing, China
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, Nanjing Agricultural University, Nanjing, China
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Zhang B, Xu J, Sun M, Yu P, Ma Y, Xie L, Chen L. Comparative secretomic and proteomic analysis reveal multiple defensive strategies developed by Vibrio cholerae against the heavy metal (Cd 2+, Ni 2+, Pb 2+, and Zn 2+) stresses. Front Microbiol 2023; 14:1294177. [PMID: 37954246 PMCID: PMC10637575 DOI: 10.3389/fmicb.2023.1294177] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Accepted: 10/10/2023] [Indexed: 11/14/2023] Open
Abstract
Vibrio cholerae is a common waterborne pathogen that can cause pandemic cholera in humans. The bacterium with heavy metal-tolerant phenotypes is frequently isolated from aquatic products, however, its tolerance mechanisms remain unclear. In this study, we investigated for the first time the response of such V. cholerae isolates (n = 3) toward the heavy metal (Cd2+, Ni2+, Pb2+, and Zn2+) stresses by comparative secretomic and proteomic analyses. The results showed that sublethal concentrations of the Pb2+ (200 μg/mL), Cd2+ (12.5 μg/mL), and Zn2+ (50 μg/mL) stresses for 2 h significantly decreased the bacterial cell membrane fluidity, but increased cell surface hydrophobicity and inner membrane permeability, whereas the Ni2+ (50 μg/mL) stress increased cell membrane fluidity (p < 0.05). The comparative secretomic and proteomic analysis revealed differentially expressed extracellular and intracellular proteins involved in common metabolic pathways in the V. cholerae isolates to reduce cytotoxicity of the heavy metal stresses, such as biosorption, transportation and effluxing, extracellular sequestration, and intracellular antioxidative defense. Meanwhile, different defensive strategies were also found in the V. cholerae isolates to cope with different heavy metal damage. Remarkably, a number of putative virulence and resistance-associated proteins were produced and/or secreted by the V. cholerae isolates under the heavy metal stresses, suggesting an increased health risk in the aquatic products.
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Affiliation(s)
- Beiyu Zhang
- Key Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation (Shanghai), Ministry of Agriculture and Rural Affairs of the People’s Republic of China, Shanghai, China
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
| | - Jingjing Xu
- Key Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation (Shanghai), Ministry of Agriculture and Rural Affairs of the People’s Republic of China, Shanghai, China
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
| | - Meng Sun
- Key Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation (Shanghai), Ministry of Agriculture and Rural Affairs of the People’s Republic of China, Shanghai, China
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
| | - Pan Yu
- Key Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation (Shanghai), Ministry of Agriculture and Rural Affairs of the People’s Republic of China, Shanghai, China
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
| | - Yuming Ma
- Key Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation (Shanghai), Ministry of Agriculture and Rural Affairs of the People’s Republic of China, Shanghai, China
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
| | - Lu Xie
- Shanghai-MOST Key Laboratory of Health and Disease Genomics (Chinese National Human Genome Center at Shanghai), Institute of Genome and Bioinformatics, Shanghai Institute for Biomedical and Pharmaceutical Technologies, Shanghai, China
| | - Lanming Chen
- Key Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation (Shanghai), Ministry of Agriculture and Rural Affairs of the People’s Republic of China, Shanghai, China
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
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Wang T, Yin Y, Zhang J, Guan H, Xu J, Liu X. Extracellular vesicles as a strategy for cadmium secretion in bacteria SH225. CHEMOSPHERE 2023; 324:138373. [PMID: 36906001 DOI: 10.1016/j.chemosphere.2023.138373] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 02/17/2023] [Accepted: 03/08/2023] [Indexed: 06/18/2023]
Abstract
Cadmium (Cd), as one of the most carcinogenic substances, poses a great threat to human health. With the development of microbial remediation technology, the necessity for urgent research into the mechanism of Cd toxicity to bacteria has arisen. In this study, a highly Cd-tolerant strain (up to 225 mg/L) was isolated and purified from Cd-contaminated soil, which was identified by 16S rRNA as a strain of Stenotrophomonas sp., thus manually designated as SH225. By testing OD600 of the strain, we indicated that Cd concentrations below 100 mg/L had no discernible impact on the biomass of SH225. When the Cd concentration was over 100 mg/L, the cell growth was significantly inhibited, while the number of extracellular vesicles (EVs) was greatly elevated. After extraction, cell-secreted EVs were confirmed to contain large amounts of Cd cations, highlighting the crucial function of EVs in the Cd detoxification of SH225. Meanwhile, the TCA cycle was vastly enhanced, suggesting that the cells provided adequate energy supply for EVs transport. Thus, these findings emphasized the crucial role played by vesicles and TCA cycle in Cd detoxification.
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Affiliation(s)
- Tong Wang
- College of Environmental & Natural Resources, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Hangzhou 310058, China
| | - Yiran Yin
- College of Life Sciences, Zhejiang University, Hangzhou 310058, China
| | - Jiawen Zhang
- College of Environmental & Natural Resources, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Hangzhou 310058, China
| | - Haoran Guan
- College of Environmental & Natural Resources, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Hangzhou 310058, China
| | - Jianming Xu
- College of Environmental & Natural Resources, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Hangzhou 310058, China
| | - Xingmei Liu
- College of Environmental & Natural Resources, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Hangzhou 310058, China.
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Ke X, Xu J, Wang X, Zhu B, Han F, Tang L, Jiang Z, Gu T, Li Z. Extracting extracellular polymeric substances from fungi in contrasts: from quantity to quality. Appl Microbiol Biotechnol 2023; 107:943-954. [PMID: 36625912 DOI: 10.1007/s00253-022-12346-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 12/19/2022] [Accepted: 12/22/2022] [Indexed: 01/11/2023]
Abstract
Many fungi are able to produce extracellular polymeric substances (EPS) for environmental, food, and industrial applications. This study evaluated the extraction (in vivo) of EPS from Rhodotorula mucilaginosa, a typical yeast with abundant EPS. Three extracting methods were set, i.e., heating, addition of NaCl during heating, and cation exchange resin (CER). The abundance of extracted proteins and polysaccharides showed evident contrasts (elevated to ~ 600 and 1700 mg/L, respectively) after heating at 70 °C in water. Although the higher temperature will increase the extracted abundance of EPS, the leakage of DNA would be enhanced due to cell rupture. The addition of NaCl further promoted the efficiency of extraction, either for proteins (from ~ 550 to ~ 650 mg/L) or polysaccharides (from ~ 1700 to ~ 2010 mg/L). Moreover, the biochemical results showed that the extracted abundance of EPS via heating was dramatically higher than that via CER. Additionally, DNA leakage in the CER treatment (2.0 g/g DW) was significantly higher (up to > 6 mg/L) than that under heating at 70 °C (< 2 mg/L). Furthermore, the three-dimensional excitation-emission matrix spectra showed two characteristic peaks of emission/excitation wavelength at 280/300 and 280/350, suggesting the relative high diversity of organic matters in EPS after heating treatments. Finally, a fluctuation of polysaccharide abundance in EPS at 500-1500 mg/L Pb2+ level was elucidated by the extraction based on heating treatment. This study hence confirmed that the heating method might be recommended for extraction of EPS from fungi in vivo KEY POINTS: • 3D-EEM results indicated that heating could extract more EPS compared with CER. • Heating treatments showed lower DNA leakage from fungi than CER treatments. • Addition of NaCl promoted the detachment of EPS from fungal cells in vivo.
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Affiliation(s)
- Xinyi Ke
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, China.,State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430074, Hubei, China
| | - Junjie Xu
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, China
| | - Xuewei Wang
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, China
| | - Bihe Zhu
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, China
| | - Feiyu Han
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, China
| | - Lingyi Tang
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, China
| | - Zhongquan Jiang
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, China
| | - Tingting Gu
- State Key Lab Plant Genet & Germplasm Enhancement, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, China
| | - Zhen Li
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, China. .,State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430074, Hubei, China. .,Jiangsu Provincial Key Lab of Organic Solid Waste Utilization, Nanjing Agricultural University, Nanjing, 210095, China.
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Feng H, Meng P, Zhang S, Chen W, Wang H, Wang C. Insights from comparative transcriptome analysis in the responses of Pb-tolerant fungi Curvularia tsudae to Pb stress. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 249:114476. [PMID: 38321691 DOI: 10.1016/j.ecoenv.2022.114476] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Revised: 12/06/2022] [Accepted: 12/23/2022] [Indexed: 02/08/2024]
Abstract
The fungus Curvularia tsudae can survive in environments that are extremely contaminated by heavy metals; however, the underlying molecular mechanisms of heavy metal tolerance are not clear. In this study, we determined the effects of lead (Pb) stress on the growth of C. tsudae and used RNA-Seq to identify significant genes and biological processes involved. The present study showed that C. tsudae had an outstanding resistant capacity to Pb stress and could survive at a concentration of 1600 mg L-1 Pb. Although an obvious inhibition on the growth was observed, the fungus exhibited tolerance as it continued to grow at a Pb concentration of 1600 mg L-1 for seven days. A total of 9997 (9020 up and 977 down) differentially expressed genes (DEGs) were detected in the mycelium of C. tsudae at Pb free (0 mg L-1) and Pb stressed samples. Pathway enrichment analysis identified several biological processes for managing Pb stress. Genes involved in carbohydrate metabolism tended to be modulated in response to Pb stress, while amino acids and the lipid metabolism would also be induced by Pb stress, and up-regulated genes involved in antioxidant substances and ABC transporters may be committed to high Pb tolerance. Our study contributes to the current literature on C. tsudae response to Pb stress and provides a useful reference for fungi as bioremediators in heavy metal-contaminated environments.
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Affiliation(s)
- Huan Feng
- College of Forestry, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Panpan Meng
- College of Forestry, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Shouxia Zhang
- College of Forestry, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Wei Chen
- College of Forestry, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Haihua Wang
- North Florida Research and Education Center, University of Florida, 155 Research Road, Quincy, FL 32351, USA
| | - Chunyan Wang
- College of Forestry, Northwest A&F University, Yangling 712100, Shaanxi, China.
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