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Zhou B, Yang Z, Chen X, Jia R, Yao S, Gan B, Fan D, Yang X, Li W, Chen Y. Microbiological Mechanisms of Collaborative Remediation of Cadmium-Contaminated Soil with Bacillus cereus and Lawn Plants. PLANTS (BASEL, SWITZERLAND) 2024; 13:1303. [PMID: 38794373 PMCID: PMC11124894 DOI: 10.3390/plants13101303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Revised: 05/03/2024] [Accepted: 05/07/2024] [Indexed: 05/26/2024]
Abstract
Severe cadmium contamination poses a serious threat to food security and human health. Plant-microbial combined remediation represents a potential technique for reducing heavy metals in soil. The main objective of this study is to explore the remediation mechanism of cadmium-contaminated soil using a combined approach of lawn plants and microbes. The target bacterium Bacillus cereus was selected from cadmium-contaminated soil in mining areas, and two lawn plants (Festuca arundinacea A'rid III' and Poa pratensis M'idnight II') were chosen as the target plants. We investigated the remediation effect of different concentrations of bacterial solution on cadmium-contaminated soil using two lawn plants through pot experiments, as well as the impact on the soil microbial community structure. The results demonstrate that Bacillus cereus promotes plant growth, and the combined action of lawn plants and Bacillus cereus improves soil quality, enhancing the bioavailability of cadmium in the soil. At a bacterial suspension concentration of 105 CFU/mL, the optimal remediation treatment was observed. The removal efficiency of cadmium in the soil under Festuca arundinacea and Poa pratensis treatments reached 33.69% and 33.33%, respectively. Additionally, the content of bioavailable cadmium in the rhizosphere soil increased by up to 13.43% and 26.54%, respectively. Bacillus cereus increased the bacterial diversity in the non-rhizosphere soil of both lawn plants but reduced it in the rhizosphere soil. Additionally, the relative abundance of Actinobacteriota and Firmicutes, which have potential for heavy metal remediation, increased after the application of the bacterial solution. This study demonstrates that Bacillus cereus can enhance the potential of lawn plants to remediate cadmium-contaminated soil and reshape the microbial communities in both rhizosphere and non-rhizosphere soils.
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Affiliation(s)
- Beibei Zhou
- State Key Laboratory of Eco-Hydraulics in Northwest Arid Region of China, Xi’an University of Technology, Xi’an 710048, China
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Zhang Y, Zhou Q, Gao C, Lu Y, Sheng Y, Xiao M, Yun Y, Selvaraj JN, Zhang X, Li Y, Yu X. Endophytic bacteria for Cd remediation in rice: Unraveling the Cd tolerance mechanisms of Cupriavidus metallidurans CML2. JOURNAL OF HAZARDOUS MATERIALS 2024; 469:133846. [PMID: 38412644 DOI: 10.1016/j.jhazmat.2024.133846] [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: 11/29/2023] [Revised: 01/30/2024] [Accepted: 02/18/2024] [Indexed: 02/29/2024]
Abstract
The utility of endophytic bacteria in Cadmium (Cd) remediation has gained significant attention due to their ability to alleviate metal-induced stress and enhance plant growth. Here, we investigate C. metallidurans CML2, an endophytic bacterial strain prevalent in rice, showing resilience against 2400 mg/L of Cd(II). We conducted an in-depth integrated morphological and transcriptomic analysis illustrating the multifarious mechanisms CML2 employs to combat Cd, including the formation of biofilm and CdO nanoparticles, upregulation of genes involved in periplasmic immobilization, and the utilization of RND efflux pumps to extract excess Cd ions. Beyond Cd, CML2 exhibited robust tolerance to an array of heavy metals, including Mn2+, Se4+, Ni2+, Cu2+, and Hg2+, demonstrating effective Cd(II) removal capacity. Furthermore, CML2 has exhibited plant growth-promoting properties through the production of indole-3-acetic acid (IAA) at 0.93 mg/L, soluble phosphorus compounds at 1.11 mg/L, and siderophores at 22.67%. Supportively, pot experiments indicated an increase in root lengths and a decrease in Cd bioaccumulation in rice seedlings inoculated with CML2, consequently reducing Cd translocation rates from 43% to 31%. These findings not only contribute to the understanding of Cd resistance mechanisms in C. metallidurans, but also underscore CML2's promising application in Cd remediation within rice farming ecosystems.
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Affiliation(s)
- Yuan Zhang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan 430062, PR China
| | - Qi Zhou
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan 430062, PR China
| | - Chang Gao
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan 430062, PR China
| | - Yue Lu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan 430062, PR China
| | - Yang Sheng
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan 430062, PR China
| | - Ming Xiao
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan 430062, PR China
| | - Yueli Yun
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan 430062, PR China
| | - Jonathan Nimal Selvaraj
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan 430062, PR China
| | - Xianhua Zhang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan 430062, PR China
| | - Yadong Li
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan 430062, PR China
| | - Xuejing Yu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan 430062, PR China.
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Liu F, Zhang K, Zhao Y, Li D, Sun X, Lin L, Feng H, Huang Q, Zhu Z. Screening of cadmium-chromium-tolerant strains and synergistic remediation of heavy metal-contaminated soil using king grass combined with highly efficient microbial strains. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:168990. [PMID: 38043805 DOI: 10.1016/j.scitotenv.2023.168990] [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: 10/10/2023] [Revised: 11/27/2023] [Accepted: 11/27/2023] [Indexed: 12/05/2023]
Abstract
The present study involved the isolation of two cadmium (Cd) and chromium (Cr) resistant strains, identified as Staphylococcus cohnii L1-N1 and Bacillus cereus CKN12, from heavy metal contaminated soils. S. cohnii L1-N1 exhibited a reduction of 24.4 % in Cr6+ and an adsorption rate of 6.43 % for Cd over a period of 5 days. These results were achieved under optimal conditions of pH (7.0), temperature (35 °C), shaking speed (200 rpm), and inoculum volume (8 %). B. cereus strain CKN12 exhibited complete reduction of Cr6+ within a span of 48 h, while it demonstrated a 57.3 % adsorption capacity for Cd over a period of 120 h. These results were achieved under conditions of optimal pH (8.0), temperature (40 °C), shaking speed (150 rpm), and inoculum volume (2-3 %). Additionally, microcharacterization and ICP-MS analysis revealed that Cr and Cd were accumulated on the cell surface, whereas Cr6+ was mainly reduced extracellularly. Subsequently, a series of pot experiments were conducted to provide evidence that the inclusion of S. cohnii L1-N1 or B. cereus CKN12 into the system resulted in a notable enhancement in both the plant height and biomass of king grass. In particular, it was observed that the presence of S. cohnii L1-N1 or B. cereus CKN12 in king grass led to a significant reduction in the levels of Cd and Cr in the soils (36.0 % and 27.8 %, or 72.9 % and 47.4 %, respectively). Thus, the results of this study indicate that the combined use of two bacterial strains can effectively aid in the remediation of tropical soils contaminated with moderate to light levels of Cd and Cr.
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Affiliation(s)
- Fan Liu
- School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
| | - Kailu Zhang
- School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
| | - Yang Zhao
- School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
| | - Dong Li
- School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
| | - Xiaoyan Sun
- School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
| | - Li Lin
- Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Guangxi Key Laboratory of Sugarcane Genetic Improvement, Ministry of Agriculture and Rural Affairs, Nanning 530007, China
| | - Huiping Feng
- School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
| | - Qing Huang
- Key Laboratory for Environmental Toxicology of Haikou, Center for Eco-Environmental Restoration Laboratory of Marine Resource Utilization in South China Sea, Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, School of Ecology and Environment, Hainan University, Haikou 570228, China
| | - Zhiqiang Zhu
- School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China.
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Fan R, Xie W, Ma H, Zhu M, Ma K, Yan X. Isolation of cadmium-resistant microbial strains and their immobilisation of cadmium in soil. Biodegradation 2023; 34:445-459. [PMID: 37043132 DOI: 10.1007/s10532-023-10026-5] [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: 10/16/2022] [Accepted: 03/24/2023] [Indexed: 04/13/2023]
Abstract
Six cadmium (Cd)-resistant microbial strains were isolated and their ability to immobilise Cd2+ in soil investigated. Cd-1, Cd-2, Cd-5, and Cd-6 were identified as Stenotrophomonas sp., Cd-3 as Achromobacter sp., and Cd-7 as Staphylococcus sp. The six strains showed a wide adaptation range for salinity and a strong tolerance to Cd2+. The effects of the initial Cd2+ concentration (1-100 mg/L), duration (18-72 h), temperature (10-40 °C), and pH (5.0-9.0) on the efficiency of Cd2+ removal were analysed. The results revealed that the Cd2+ removal rate was higher at an initial Cd2+ concentration of 5-100 mg/L than at 1 mg/L. The maximum Cd2+ removal effect was at a culture duration of 36 h, temperature of 10-35 °C, and pH of 5.0-7.0. X-ray diffraction (XRD) analysis revealed that the Cd2+ was immobilised by Stenotrophomonas sp. Cd-2 and Staphylococcus sp. Cd-7 through bio-precipitation. X-ray photoelectron spectroscopy (XPS) revealed that the Cd2+ was adsorbed by Stenotrophomonas sp. Cd-2, Achromobacter sp. Cd-3, and Staphylococcus sp. Cd-7. Fourier transform infrared spectroscopy (FTIR) analysis revealed that the isolates reacted with the Cd2+ mainly through the O-H, protein N-H, C-N, lipid C-H, fatty acid COO, polysaccharide C-O, P-O, and other functional groups, as well as with lipid molecules on the cell wall surfaces. Scanning electron microscopy (SEM) analysis revealed that there was little difference in the cells after Cd2+ treatment. The results of the soil remediation experiments indicated that the toxicity of Cd in soil could be effectively reduced using certain strains of microbe.
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Affiliation(s)
- Ruijuan Fan
- College of Biological Science & Engineering, North Minzu University, Yinchuan, 750021, China.
- Key Laboratory of Ecological Protection of Agro-Pastoral Ecotones in the Yellow River Basin, National Ethnic Affairs Commission of the People's Republic of China, Yinchuan, 750021, China.
| | - Weixia Xie
- College of Biological Science & Engineering, North Minzu University, Yinchuan, 750021, China
| | - Heqin Ma
- College of Biological Science & Engineering, North Minzu University, Yinchuan, 750021, China
| | - Mengke Zhu
- College of Biological Science & Engineering, North Minzu University, Yinchuan, 750021, China
| | - Kun Ma
- Key Laboratory for Restoration and Reconstruction of Degraded Ecosystem in Northwestern China of Ministry of Education, Ningxia University, Yinchuan, 750021, China
- National Key Laboratory Breeding Base of Northwest Land Degradation and Ecological Restoration, Ningxia University, Yinchuan, 750021, China
| | - Xingfu Yan
- College of Biological Science & Engineering, North Minzu University, Yinchuan, 750021, China
- Key Laboratory of Ecological Protection of Agro-Pastoral Ecotones in the Yellow River Basin, National Ethnic Affairs Commission of the People's Republic of China, Yinchuan, 750021, 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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Shi Z, Zhang J, Jiang Y, Wen Y, Gao Z, Deng W, Yin Y, Zhu F. Two low-toxic Klebsiella pneumoniae strains from gut of black soldier fly Hermetia illucens are multi-resistance to sulfonamides and cadmium. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 312:120062. [PMID: 36049579 DOI: 10.1016/j.envpol.2022.120062] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 08/23/2022] [Accepted: 08/24/2022] [Indexed: 06/15/2023]
Abstract
In recent years, pollution of antibiotics and heavy metal has often been reported in organic wastes. Saprophytic insects have been recorded as biological control agents in organic waste management. During organic waste conversion, the intestinal bacteria of the saprophytic insects play an important role in digestion, physiology, immunity and prevention of pathogen colonization. Black soldier fly (BSF) Hermetia illucens has been widely used as saprophytic insects and showed tolerance to sulfonamides (SAs) and cadmium (Cd). Diversity and changes in gut microbiota of black soldier fly larvae (BSFL) were evaluated through 16S rRNA high-throughput sequencing, and a decrease in diversity of gut microbiota along with an increase in SAs stress was recorded. Major members identified were Actinomycetaceae, Enterobacteriaceae, and Enterococcaceae. And fourteen multi-resistance Klebsiella pneumoniae strains were isolated. Two strains BSFL7-B-5 (from middle midgut of 7-day BSFL) and BSFL11-C-1 (from posterior midgut of 11-day BSFL) were found to be low-toxic and multi-resistance. The adsorption rate of SAs in 5 mg/kg solutions by these two strains reached 65.2% and 61.6%, respectively. Adsorption rate of Cd in 20 mg/L solutions was 77.2% for BSFL7-B-5. The strain BSFL11-C-1 showed higher than 70% adsorption rates of Cd in 20, 30 and 40 mg/L solutions. This study revealed that the presence of multi-resistance bacterial strains in the gut of BSFL helped the larvae against SAs or Cd stress. After determining how and where they are used, selected BSFL gut bacterial strains might be utilized in managing SAs or Cd contamination at suitable concentrations in the future.
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Affiliation(s)
- Zhihui Shi
- Hubei International Scientific and Technological Cooperation Base of Waste Conversion by Insects, Huazhong Agricultural University, Wuhan, 430070, China.
| | - Jie Zhang
- Hubei International Scientific and Technological Cooperation Base of Waste Conversion by Insects, Huazhong Agricultural University, Wuhan, 430070, China.
| | - Yijie Jiang
- Hubei International Scientific and Technological Cooperation Base of Waste Conversion by Insects, Huazhong Agricultural University, Wuhan, 430070, China.
| | - Yiting Wen
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, Huazhong Agricultural University, Wuhan, 430070, China.
| | - Zhenghui Gao
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, Huazhong Agricultural University, Wuhan, 430070, China.
| | - Wenhui Deng
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, Huazhong Agricultural University, Wuhan, 430070, China.
| | - Yumeng Yin
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, Huazhong Agricultural University, Wuhan, 430070, China.
| | - Fen Zhu
- Hubei International Scientific and Technological Cooperation Base of Waste Conversion by Insects, Huazhong Agricultural University, Wuhan, 430070, China; Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, Huazhong Agricultural University, Wuhan, 430070, China.
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Shahid M, Zeyad MT, Syed A, Singh UB, Mohamed A, Bahkali AH, Elgorban AM, Pichtel J. Stress-Tolerant Endophytic Isolate Priestia aryabhattai BPR-9 Modulates Physio-Biochemical Mechanisms in Wheat ( Triticum aestivum L.) for Enhanced Salt Tolerance. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph191710883. [PMID: 36078599 PMCID: PMC9518148 DOI: 10.3390/ijerph191710883] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Revised: 08/16/2022] [Accepted: 08/24/2022] [Indexed: 05/28/2023]
Abstract
In efforts to improve plant productivity and enhance defense mechanisms against biotic and abiotic stresses, endophytic bacteria have been used as an alternative to chemical fertilizers and pesticides. In the current study, 25 endophytic microbes recovered from plant organs of Triticum aestivum L. (wheat) were assessed for biotic (phyto-fungal pathogens) and abiotic (salinity, drought, and heavy metal) stress tolerance. Among the recovered isolates, BPR-9 tolerated maximum salinity (18% NaCl), drought (15% PEG-6000), and heavy metals (µg mL-1): Cd (1200), Cr (1000), Cu (1000), Pb (800), and Hg (30). Based on phenotypic and biochemical characteristics, as well as 16S rDNA gene sequencing, endophytic isolate BPR-9 was recognized as Priestia aryabhattai (accession no. OM743254.1). This isolate was revealed as a powerful multi-stress-tolerant crop growth promoter after extensive in-vitro testing for plant growth-promoting attributes, nutrient (phosphate, P; potassium, K; and zinc, Zn) solubilization efficiency, extracellular enzyme (protease, cellulase, amylase, lipase, and pectinase) synthesis, and potential for antagonistic activity against important fungal pathogens viz. Alternaria solani, Rhizoctonia solani, Fusarium oxysporum, and Ustilaginoidea virens. At elevated salt levels, increases were noted in indole-3-acetic acid; siderophores; P, K, and Zn-solubilization; ACC deaminase; and ammonia synthesized by Priestia aryabhattai. Additionally, under in-vitro plant bioassays, wheat seedlings inoculated with P. aryabhattai experienced superior growth compared to non-inoculated seedlings in high salinity (0-15% NaCl) environment. Under NaCl stress, germination rate, plant length, vigor indices, and leaf pigments of wheat seedlings significantly increased following P. aryabhattai inoculation. Furthermore, at 2%-NaCl, B. aryabhattai greatly and significantly (p ≤ 0.05) decreased relative leaf water content, membrane damage, and electrolyte leakage compared with the non-inoculated control. Catalase, superoxide dismutase, and peroxidase activity increased by 29, 32, and 21%, respectively, in wheat seedlings exposed to 2% NaCl and inoculated with the bacteria. The present findings demonstrate that endophytic P. aryabhattai strains might be used in the future as a multi-stress reducer and crop growth promoter in agronomically important crops including cereals.
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Affiliation(s)
- Mohammad Shahid
- Plant-Microbe Interaction and Rhizosphere Biology Lab, ICAR-National Bureau of Agriculturally Important Microorganisms (NBAIM), Mau 275103, India
- Department of Agricultural Microbiology, Faculty of Agricultural Sciences, Aligarh Muslim University, Aligarh 202002, India
| | - Mohammad Tarique Zeyad
- Department of Agricultural Microbiology, Faculty of Agricultural Sciences, Aligarh Muslim University, Aligarh 202002, India
- ICAR-National Bureau of Agriculturally Important Microorganisms (NBAIM), Mau 275103, India
| | - Asad Syed
- Department of Botany and Microbiology, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia
| | - Udai B. Singh
- Plant-Microbe Interaction and Rhizosphere Biology Lab, ICAR-National Bureau of Agriculturally Important Microorganisms (NBAIM), Mau 275103, India
| | - Abdullah Mohamed
- Research Centre, Future University in Egypt, New Cairo 11835, Egypt
| | - Ali H. Bahkali
- Department of Botany and Microbiology, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia
| | - Abdallah M. Elgorban
- Department of Botany and Microbiology, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia
| | - John Pichtel
- Natural Resources and Environmental Management, Ball State University, Muncie, IN 47306, USA
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Tolerance and Cadmium (Cd) Immobilization by Native Bacteria Isolated in Cocoa Soils with Increased Metal Content. MICROBIOLOGY RESEARCH 2022. [DOI: 10.3390/microbiolres13030039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Twelve cadmium native bacteria previously isolated in soils of cocoa farms located in the western Colombian Andes (Santander), and tolerant to 2500 µM CdCl2 (120 mg Cd/L), were chosen in order to test their tolerance and Cd immobilization using liquid culture medium (Nutritive broth) at different concentrations of heavy metals. Furthermore, in the greenhouse experiments, the strains Exiguobacterium sp. (11-4A), Klebsiella variicola sp. (18-4B), and Enterobacter sp. (29-4B) were applied in combined treatments using CCN51 cacao genotype seeds grown in soil with different concentrations of Cd. All bacterial strains’ cell morphologies were deformed in TEM pictures, which also identified six strain interactions with biosorption and four strain capacities for bioaccumulation; FT-IR suggested that the amide, carbonyl, hydroxyl, ethyl, and phosphate groups on the bacteria biomass were the main Cd binding sites. In the pot experiments, the concentration of Cd was distributed throughout the cacao plant, but certain degrees of immobilization of Cd can occur in soil to prevent an increase in this level in roots with the presence of Klebsiella sp.
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Bravo D, Braissant O. Cadmium-tolerant bacteria: current trends and applications in agriculture. Lett Appl Microbiol 2021; 74:311-333. [PMID: 34714944 PMCID: PMC9299123 DOI: 10.1111/lam.13594] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 09/28/2021] [Accepted: 10/15/2021] [Indexed: 12/17/2022]
Abstract
Cadmium (Cd) is considered a toxic heavy metal; nevertheless, its toxicity fluctuates for different organisms. Cadmium-tolerant bacteria (CdtB) are diverse and non-phylogenetically related. Because of their ecological importance these bacteria become particularly relevant when pollution occurs and where human health is impacted. The aim of this review is to show the significance, culturable diversity, metabolic detoxification mechanisms of CdtB and their current uses in several bioremediation processes applied to agricultural soils. Further discussion addressed the technological devices and the possible advantages of genetically modified CdtB for diagnostic purposes in the future.
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Affiliation(s)
- D Bravo
- Laboratory of Soil Microbiology & Calorimetry, Corporación Colombiana de Investigación Agropecuaria AGROSAVIA, Mosquera, Colombia
| | - O Braissant
- Department of Biomedical Engineering, Faculty of Medicine, University of Basel, Allschwill, Switzerland
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