1
|
Singh S, Kumar V, Gupta P, Ray M. The trafficking of Hg II by alleviating its toxicity via Citrobacter sp. IITISM25 in batch and pilot-scale investigation. J Hazard Mater 2022; 433:128711. [PMID: 35395524 DOI: 10.1016/j.jhazmat.2022.128711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 03/10/2022] [Accepted: 03/13/2022] [Indexed: 06/14/2023]
Abstract
The study aims to see how effective the Citrobacter species strain is in removing HgII under stressful conditions. For this, a response surface methodology was chosen to optimized pH, temperature, and biomass for effective biotransformation of HgII. The optimized value for pH, temperature, and biomass were 6.5, 30 °C, and 2 mg/l with 89% HgII removal potential. TEM-EDX showed accumulated mercury onto the bacterial surface. Pot study was conducted to check the potentiality of this strain in alleviating the toxicity in Solanum lycopersicum L. under different concentrations of mercury. The enhancement in antioxidative enzymes, as well as mercury accumulation, was observed in test plants inoculated with IITISM25. Obtained result showed a greater accumulation of mercury in the root system than that of the shoot system due to poor translocation. Moreover, mercury reductase enzyme synthesis was also boosted by the addition of β-mercaptoethanol and L-cysteine. The optimized condition for maximum enzyme synthesis was at pH 7.5 and temperature 30 °C with Km = 48.07 μmol and Vmax = 9.75 μmol/min. Thus, we can say that Citrobacter species strain IITISM25 can be effectively applied in remediation of HgII stress condition as well as promotion of Solanum lycopersicum L growth under stress conditions as a promising host.
Collapse
Affiliation(s)
- Shalini Singh
- Laboratory of Applied Microbiology, Department of Environmental Science & Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad 826 004, Jharkhand, India
| | - Vipin Kumar
- Laboratory of Applied Microbiology, Department of Environmental Science & Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad 826 004, Jharkhand, India.
| | - Pratishtha Gupta
- Laboratory of Applied Microbiology, Department of Environmental Science & Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad 826 004, Jharkhand, India
| | - Madhurya Ray
- Laboratory of Applied Microbiology, Department of Environmental Science & Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad 826 004, Jharkhand, India
| |
Collapse
|
2
|
Belsare KD, Ruff AJ, Martinez R, Schwaneberg U. Insights on intermolecular FMN-heme domain interaction and the role of linker length in cytochrome P450cin fusion proteins. Biol Chem 2021; 401:1249-1255. [PMID: 32549121 DOI: 10.1515/hsz-2020-0134] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 05/25/2020] [Indexed: 11/15/2022]
Abstract
Cytochrome P450s are an important group of enzymes catalyzing hydroxylation, and epoxidations reactions. In this work we describe the characterization of the CinA-CinC fusion enzyme system of a previously reported P450 using genetically fused heme (CinA) and FMN (CinC) enzyme domains from Citrobacter braaki. We observed that mixing individually inactivated heme (-) with FMN (-) domain in the CinA-10aa linker - CinC fusion constructs results in recovered activity and the formation of (2S)-2β-hydroxy,1,8-cineole (174 µM), a similar amount when compared to the fully functional fusion protein (176 µM). We also studied the effect of the fusion linker length in the activity complementation assay. Our results suggests an intermolecular interaction between heme and FMN parts from different CinA-CinC fusion protein similar to proposed mechanisms for P450 BM3 on the other hand, linker length plays a crucial influence on the activity of the fusion constructs. However, complementation assays show that inactive constructs with shorter linker lengths have functional subunits, and that the lack of activity might be due to incorrect interaction between fused enzymes.
Collapse
Affiliation(s)
- Ketaki D Belsare
- Lehrstuhl für Biotechnologie, RWTH Aachen University, Worringerweg 3, Aachen, D-52074, Germany
- University of California at San Francisco, 555 Mission Bay Blvd South, San Francisco, 94158, CA, USA
| | - Anna Joëlle Ruff
- Lehrstuhl für Biotechnologie, RWTH Aachen University, Worringerweg 3, Aachen, D-52074, Germany
| | - Ronny Martinez
- Lehrstuhl für Biotechnologie, RWTH Aachen University, Worringerweg 3, Aachen, D-52074, Germany
- Departamento de Ingeniería en Alimentos, Universidad de La Serena, Av. Raúl Bitrán 1305, La Serena, 1720010, Chile
| | - Ulrich Schwaneberg
- Lehrstuhl für Biotechnologie, RWTH Aachen University, Worringerweg 3, Aachen, D-52074, Germany
- DWI - Leibniz Institut für Interaktive Materialien, Forckenbeckstraße 50, Aachen, D-52074, Germany
| |
Collapse
|
3
|
Dersjant-Li Y, Davin R, Christensen T, Kwakernaak C. Effect of two phytases at two doses on performance and phytate degradation in broilers during 1-21 days of age. PLoS One 2021; 16:e0247420. [PMID: 33765064 PMCID: PMC7993876 DOI: 10.1371/journal.pone.0247420] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Accepted: 02/07/2021] [Indexed: 11/18/2022] Open
Abstract
The effect of two microbial phytases at two dose-levels on performance and apparent ileal digestibility (AID) of nutrients in broilers fed European-type diets was studied. A total of 1,200 d-old Ross 308 male broilers were randomly assigned to 5 treatments with 30 birds/pen and 8 pens/treatment. A nutritionally adequate positive control (PC) diet was tested against 4 experimental diets containing reduced total P, retainable P, Ca and Na as per the recommended nutritional contribution for Buttiauxella phytase (Phy B) at 1,000 FTU/kg (-1.87 g/kg, -1.59 g/kg, -1.99 g/kg and -0.4 g/kg vs. PC, respectively). Experimental diets were supplemented with Phy B at 500 FTU/kg or 1,000 FTU/kg, or Citrobacter phytase (Phy C) at 1,000 FTU/kg or 2,000 FTU/kg. Diets were based on corn, soybean meal, rapeseed meal and sunflower meal and formulated by phase (starter 1–10 d, grower 11–21 d) in crumbled or pelleted form. Overall (d 1–21), at 1,000 FTU/kg, birds fed Phy C exhibited lower BWG (-2.7%), FI (-3.4%) and tibia ash (-2.2%) vs. PC (P < 0.05), and reduced BWG (-3.6%), FI (-3.9%) and tibia ash (-1.8%) vs. Phy B (P < 0.05). Phy B at 1,000 FTU/kg and Phy C at 2,000 FTU/kg maintained performance equivalent to the PC. Digestibility of Ca did not differ among phytase treatments but at 1,000 FTU/kg AID P was greater with Phy B than Phy C (72.3% vs. 62.7%, P < 0.05). Ileal phytate (myo-inositol hexakisphosphate, IP6) digestibility was greatest with Phy B at 1,000 FTU/kg which was higher than Phy C at 1,000 FTU/kg (87.6 vs. 60.6%, P < 0.05). The findings indicate a higher phytate degradation rate of Phy B than Phy C at equivalent dose-level and this is correlated to the performance of the broilers.
Collapse
Affiliation(s)
| | - Roger Davin
- Schothorst Feed Research, Lelystad, The Netherlands
| | | | | |
Collapse
|
4
|
Mondal AH, Yadav D, Ali A, Khan N, Jin JO, Haq QMR. Anti-Bacterial and Anti-Candidal Activity of Silver Nanoparticles Biosynthesized Using Citrobacter spp. MS5 Culture Supernatant. Biomolecules 2020; 10:E944. [PMID: 32580522 PMCID: PMC7355547 DOI: 10.3390/biom10060944] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Revised: 06/19/2020] [Accepted: 06/19/2020] [Indexed: 01/26/2023] Open
Abstract
The present study described the extracellular synthesis of silver nanoparticles (AgNPs) using environmental bacterial isolate Citrobacter spp. MS5 culture supernatant. To our best knowledge, no previous study reported the biosynthesis of AgNPs using this bacterial isolate. The biosynthesized AgNPs were characterized using different techniques like UV-Vis spectroscopy, fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) equipped with energy dispersive X-ray (EDX). The analysis of UV-Vis spectra revealed absorption maxima at 415 nm due to surface plasmon resonance (SPR) indicated the formation of AgNPs and FTIR spectrum confirmed the participation of proteins molecule in AgNPs synthesis. XRD and EDX spectrum confirmed the metallic and crystalline nature of AgNPs. TEM and SEM showed spherical nanoparticles with a size range of 5-15 nm. The biosynthesized AgNPs showed effective independent as well as enhanced combined antibacterial activity against extended spectrum β-lactamase (ESBL) producing multidrug resistant Gram-negative bacteria. Further, effective antifungal activity of AgNPs was observed towards pathogenic Candida spp. The present study provides evidence for eco-friendly biosynthesis of well-characterized AgNPs and their potential antibacterial as well as antifungal activity.
Collapse
Affiliation(s)
- Aftab Hossain Mondal
- Department of Biosciences, Jamia Millia Islamia, New Delhi 110025, India; (A.H.M.); (A.A.); (N.K.)
| | - Dhananjay Yadav
- Department of Medical Biotechnology, Yeungnam University, Gyeongsan 712-749, Korea;
| | - Asghar Ali
- Department of Biosciences, Jamia Millia Islamia, New Delhi 110025, India; (A.H.M.); (A.A.); (N.K.)
| | - Neelofar Khan
- Department of Biosciences, Jamia Millia Islamia, New Delhi 110025, India; (A.H.M.); (A.A.); (N.K.)
| | - Jun O Jin
- Department of Medical Biotechnology, Yeungnam University, Gyeongsan 712-749, Korea;
- Research Institute of Cell Culture, Yeungnam University, Gyeongsan 38541, Korea
| | - Qazi Mohd Rizwanul Haq
- Department of Biosciences, Jamia Millia Islamia, New Delhi 110025, India; (A.H.M.); (A.A.); (N.K.)
| |
Collapse
|
5
|
Neupane DP, Fullam SH, Chacón KN, Yukl ET. Crystal structures of AztD provide mechanistic insights into direct zinc transfer between proteins. Commun Biol 2019; 2:308. [PMID: 31428696 PMCID: PMC6689063 DOI: 10.1038/s42003-019-0542-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 07/15/2019] [Indexed: 12/19/2022] Open
Abstract
Zinc acquisition from limited environments is critical for bacterial survival and pathogenesis. AztD has been identified as a periplasmic or cell surface zinc-binding protein in numerous bacterial species. In Paracoccus denitrificans, AztD can transfer zinc directly to AztC, the solute binding protein for a zinc-specific ATP-binding cassette transporter system, suggesting a role in zinc acquisition and homeostasis. Here, we present the first cry stal structures of AztD from P. denitrificans and tbe human pathogen Citrobacter koseri, revealing a beta-propeller fold and two high-affinity zinc-binding sites that are highly conserved among AztD homologs. These structures combined with transfer assays using WT and mutant proteins provide rare insight into the mechanism of direct zinc transfer from one protein to another. Given the importance of zinc import to bacterial pathogenesis, these insights may prove valuable to the development of zinc transfer inhibitors as antibiotics.
Collapse
Affiliation(s)
- Durga Prasad Neupane
- Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, NM 88003 USA
| | - Stephanie Hope Fullam
- Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, NM 88003 USA
| | | | - Erik Thomas Yukl
- Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, NM 88003 USA
| |
Collapse
|
6
|
Ueoka N, Kouzuma A, Watanabe K. Electrode plate-culture methods for colony isolation of exoelectrogens from anode microbiomes. Bioelectrochemistry 2018; 124:1-6. [PMID: 29990596 DOI: 10.1016/j.bioelechem.2018.06.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 06/19/2018] [Accepted: 06/19/2018] [Indexed: 11/17/2022]
Abstract
Exoelectrogens play central roles in microbial fuel cells and other bioelectrochemical systems (BESs), yet their physiological diversity remains largely elusive due to the lack of efficient methods for the isolation from naturally occurring microbiomes. The present study developed an electrode plate-culture (EPC) method that facilitates selective colony formation by exoelectrogens and used it for isolating them from an exoelectrogenic microbiome enriched from paddy-field soil. In an EPC device, the surface of solidified agarose medium was spread with a suspension of a microbiome and covered with a transparent fluorine doped tin oxide (FTO) electrode (poised at 0 V vs. the standard hydrogen electrode) that served as the sole electron acceptor. The medium contained acetate as the major growth substrate and Coomassie Brilliant Blue as a dye for visualizing colonies under FTO. It was shown that colonies successfully appeared under FTO in association with current generation. Analyses of 16S rRNA gene sequences of colonies indicated that they were affiliated with genera Citrobacter, Geobacter and others. Among them, Citrobacter and Geobacter isolates were found to be exoelectrogenic in pure-culture BESs. These results demonstrate the utility of the EPC method for colony isolation of exoelectrogens.
Collapse
Affiliation(s)
- N Ueoka
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, 192-0392 Tokyo, Japan
| | - A Kouzuma
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, 192-0392 Tokyo, Japan
| | - K Watanabe
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, 192-0392 Tokyo, Japan.
| |
Collapse
|
7
|
Liao HY, Chien CC, Tang P, Chen CC, Chen CY, Chen SC. The integrated analysis of transcriptome and proteome for exploring the biodegradation mechanism of 2, 4, 6-trinitrotoluene by Citrobacter sp. J Hazard Mater 2018; 349:79-90. [PMID: 29414755 DOI: 10.1016/j.jhazmat.2018.01.039] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 01/16/2018] [Accepted: 01/21/2018] [Indexed: 06/08/2023]
Abstract
Citrobacter sp. has been shown to degrade 2,4,6-trinitrotoluene (TNT). However, the mechanism of its TNT biodegradation is poorly understood. An integrated proteome and transcriptome analysis was performed for investigating the differential genes and differential proteins in bacterial growth at the onset of experiments and after 12 h treatment with TNT. With the RNA sequencing, we found a total of 3792 transcripts and 569 differentially expressed genes (≥2 fold, P < 0.05) by. Genes for amino acid transport, cellular metabolism and stress-shock proteins were up-regulated, while carbohydrate transport and metabolism were down-regulated. A total of 42 protein spots (≥1.5 fold, P < 0.05) showed differential expression on two-dimensional gel electrophoresis and these proteins were identified by mass spectrometry. The most prominent proteins up-regulated were involved in energy production and conversion, amino acid transport and metabolism, posttranslational modification, protein turnover and chaperones. Proteins involved in carbohydrate transport and metabolism were down-regulated. Most notably, we observed that nemA encoding N-ethylmaleimide reductase was the most up-regulated gene involved in TNT degradation, and further proved that it can transform TNT to 4-amino-2,6-dinitrotoluene (4-ADNT) and 2-amino-4,6-dinitrotoluene (2-ADNT). This study highlights the molecular mechanisms of Citrobacter sp. for TNT removal.
Collapse
Affiliation(s)
- Hung-Yu Liao
- Department of Life Sciences, National Central University, No. 300, Jhing-da Rd., Jhongli City, Taoyuan, 32001, Taiwan
| | - Chih-Ching Chien
- Graduate School of Biotechnology and Bioengineering, Yuan Ze University, No. 135, Yuantung Rd., Jhongli City, Taoyuan, 32003, Taiwan
| | - Petrus Tang
- Department of Parasitology, Chang Gung University, No.259, Wenhua 1st Rd., Guishan Dis., Taoyuan City, 33302, Taiwan
| | - Chien-Cheng Chen
- Department of Biotechnology, National Kaohsiung Normal University, No.116, Heping 1st Rd., Lingya District, Kaohsiung City, 80201, Taiwan
| | - Chin-Yu Chen
- Department of Life Sciences, National Central University, No. 300, Jhing-da Rd., Jhongli City, Taoyuan, 32001, Taiwan
| | - Ssu-Ching Chen
- Department of Life Sciences, National Central University, No. 300, Jhing-da Rd., Jhongli City, Taoyuan, 32001, Taiwan.
| |
Collapse
|
8
|
Zamani H, Rakhshaee R, Garakoui SR. Two contrary roles of Fe 3O 4 nanoparticles on kinetic and thermodynamic of Paclitaxel degradation by Citrobacter amalonaticus Rashtia immobilized on sodium alginate gel beads. J Hazard Mater 2018; 344:566-575. [PMID: 29102639 DOI: 10.1016/j.jhazmat.2017.10.061] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2017] [Revised: 10/23/2017] [Accepted: 10/30/2017] [Indexed: 06/07/2023]
Abstract
Roles of Fe3O4 nanoparticles (NPs) on biodegradation of Paclitaxel by Citrobacter amalonaticus immobilized on alginate gel beads were investigated. Limitation in substrate diffusion is the major drawback of the cell immobilization method. To overcome this problem, bacterial cells were immobilized on the gel beads containing different concentrations (5-20mg/mL) of Fe3O4 NPs and their Paclitaxel degrading potential at different temperatures was investigated using kinetic and thermodynamic modeling. Co-immobilization of bacterial cells with 5, 10 and 20mg/mL Fe3O4 NPs enhanced biodegradation efficiencies to 66%, 80% and 78%, respectively, compared to the NPs free immobilized cells (41.9%). The optimum concentration of Fe3O4 NPs (10mg/mL) had both inhibitory and accelerating effects on paclitaxel degradation depending on the incubation time and temperature. Increasing dose of Fe3O4 NPs could increase paclitaxel degradation, despite increasing of thermodynamic inhibitory factors, only when longer time and higher temperature were used. ΔG values increased about 11.2 KJ/mol at all temperatures of 285, 295 and 305K, and ΔH increased 54.4%, in comparison with the treatment without NPs. This indicates that, inclusion of Fe3O4 NPs into the immobilization gels can increase the local concentration of Paclitaxel (with OH2+ groups) and bacterial accessibility to the substrate and thus enhance biodegradation efficiency.
Collapse
Affiliation(s)
- Hojjatolah Zamani
- Department of Biology, Faculty of Science, University of Guilan, Iran.
| | - Roohan Rakhshaee
- Department of Chemistry, Faculty of Science, University of Guilan, Iran
| | | |
Collapse
|
9
|
Abstract
Phenol is a toxic pollutant in many kinds of hypersaline industrial effluents that should be treated properly before discharged into water bodies. In this work, a halophilic strain which could utilize phenol as the sole source of carbon and energy was isolated. Based on 16S rRNA results, it was identified as a member of Citrobacter. The phenol biodegradation ability and cell growth of the strain was evaluated with the variation of initial phenol concentration and salinity. The effect of temperature and pH on phenol removal was also investigated. The results showed that the strain was capable of withstanding high phenol (up to 1,100 mg L-1) environment with varying salinity conditions (0-10% of NaCl). The optimal initial phenol concentration was 400 mg L-1, at which the average removal rates of phenol peaked at 10.8 mg L-1 h-1. The higher initial concentration of phenol could inhibit the microbial metabolism. The optimal temperature, pH, and salinity were 35 °C, 6.0, and 0%, respectively. Under these conditions, 400 mg L-1 of phenol could be completely degraded within 20 h. The high removal rates of phenol by the strain might provide an alternative for treating phenolic wastewaters containing high salinity.
Collapse
Affiliation(s)
- Tao Deng
- School of Civil Engineering, Wuhan University, Wuhan 430072, China E-mail:
| | - Hongyu Wang
- School of Civil Engineering, Wuhan University, Wuhan 430072, China E-mail:
| | - Kai Yang
- School of Civil Engineering, Wuhan University, Wuhan 430072, China E-mail:
| |
Collapse
|
10
|
Wang J, Zeng XC, Zhu X, Chen X, Zeng X, Mu Y, Yang Y, Wang Y. Sulfate enhances the dissimilatory arsenate-respiring prokaryotes-mediated mobilization, reduction and release of insoluble arsenic and iron from the arsenic-rich sediments into groundwater. J Hazard Mater 2017; 339:409-417. [PMID: 28686931 DOI: 10.1016/j.jhazmat.2017.06.052] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 06/19/2017] [Accepted: 06/20/2017] [Indexed: 06/07/2023]
Abstract
Dissimilatory arsenate-respiring prokaryotes (DARPs) play key roles in the mobilization and release of arsenic from mineral phase into groundwater; however, little is known about how environmental factors influence these processes. This study aimed to explore the effects of sulfate on the dissolution and release of insoluble arsenic. We collected high-arsenic sediment samples from different depths in Jianghan Plain. Microcosm assays indicated that the microbial communities from the samples significantly catalyzed the dissolution, reduction and release of arsenic and iron from the sediments. Remarkably, when sulfate was added into the microcosms, the microorganisms-mediated release of arsenic and iron was significantly increased. To further explore the mechanism of this finding, we isolated a novel DARP, Citrobacter sp. JH001, from the samples. Arsenic release assays showed that JH001 can catalyze the dissolution, reduction and release of arsenic and iron from the sediments, and the presence of sulfate in the microcosms also caused a significant increase in the JH001-mediated dissolution and release of arsenic and iron. Quantitative PCR analysis for the functional gene abundances showed that sulfate significantly increased the arsenate-respiring reductase gene abundances in the microcosms. Thus, it can be concluded that sulfate significantly enhances the arsenate-respiring bacteria-mediated arsenic contamination in groundwater.
Collapse
Affiliation(s)
- Jianing Wang
- State Key Laboratory of Biogeology and Environmental Geology & Department of Biological Science and Technology, School of Environmental Studies, China University of Geosciences (Wuhan), Wuhan 430074, People's Republic of China
| | - Xian-Chun Zeng
- State Key Laboratory of Biogeology and Environmental Geology & Department of Biological Science and Technology, School of Environmental Studies, China University of Geosciences (Wuhan), Wuhan 430074, People's Republic of China.
| | - Xianbin Zhu
- State Key Laboratory of Biogeology and Environmental Geology & Department of Biological Science and Technology, School of Environmental Studies, China University of Geosciences (Wuhan), Wuhan 430074, People's Republic of China
| | - Xiaoming Chen
- State Key Laboratory of Biogeology and Environmental Geology & Department of Biological Science and Technology, School of Environmental Studies, China University of Geosciences (Wuhan), Wuhan 430074, People's Republic of China
| | - Xin Zeng
- State Key Laboratory of Biogeology and Environmental Geology & Department of Biological Science and Technology, School of Environmental Studies, China University of Geosciences (Wuhan), Wuhan 430074, People's Republic of China
| | - Yao Mu
- State Key Laboratory of Biogeology and Environmental Geology & Department of Biological Science and Technology, School of Environmental Studies, China University of Geosciences (Wuhan), Wuhan 430074, People's Republic of China
| | - Ye Yang
- State Key Laboratory of Biogeology and Environmental Geology & Department of Biological Science and Technology, School of Environmental Studies, China University of Geosciences (Wuhan), Wuhan 430074, People's Republic of China
| | - Yanxin Wang
- State Key Laboratory of Biogeology and Environmental Geology & Department of Biological Science and Technology, School of Environmental Studies, China University of Geosciences (Wuhan), Wuhan 430074, People's Republic of China
| |
Collapse
|
11
|
Liang SH, Hsu DW, Lin CY, Kao CM, Huang DJ, Chien CC, Chen SC, Tsai IJ, Chen CC. Enhancement of microbial 2,4,6-trinitrotoluene transformation with increased toxicity by exogenous nutrient amendment. Ecotoxicol Environ Saf 2017; 138:39-46. [PMID: 28006730 DOI: 10.1016/j.ecoenv.2016.12.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 11/18/2016] [Accepted: 12/08/2016] [Indexed: 06/06/2023]
Abstract
In this study, the bacterial strain Citrobacter youngae strain E4 was isolated from 2,4,6-trinitrotoluene (TNT)-contaminated soil and used to assess the capacity of TNT transformation with/without exogenous nutrient amendments. C. youngae E4 poorly degraded TNT without an exogenous amino nitrogen source, whereas the addition of an amino nitrogen source considerably increased the efficacy of TNT transformation in a dose-dependent manner. The enhanced TNT transformation of C. youngae E4 was mediated by increased cell growth and up-regulation of TNT nitroreductases, including NemA, NfsA and NfsB. This result indicates that the increase in TNT transformation by C. youngae E4 via nitrogen nutrient stimulation is a cometabolism process. Consistently, TNT transformation was effectively enhanced when C. youngae E4 was subjected to a TNT-contaminated soil slurry in the presence of an exogenous amino nitrogen amendment. Thus, effective enhancement of TNT transformation via the coordinated inoculation of the nutrient-responsive C. youngae E4 and an exogenous nitrogen amendment might be applicable for the remediation of TNT-contaminated soil. Although the TNT transformation was significantly enhanced by C. youngae E4 in concert with biostimulation, the 96-h LC50 value of the TNT transformation product mixture on the aquatic invertebrate Tigriopus japonicas was higher than the LC50 value of TNT alone. Our results suggest that exogenous nutrient amendment can enhance microbial TNT transformation; however, additional detoxification processes may be needed due to the increased toxicity after reduced TNT transformation.
Collapse
Affiliation(s)
- Shih-Hsiung Liang
- Department of Biotechnology, National Kaohsiung Normal University, Kaohsiung, Taiwan
| | - Duen-Wei Hsu
- Department of Biotechnology, National Kaohsiung Normal University, Kaohsiung, Taiwan
| | - Chia-Ying Lin
- Department of Biotechnology, National Kaohsiung Normal University, Kaohsiung, Taiwan
| | - Chih-Ming Kao
- Institute of Environmental Engineering, National Sun Yat-sen University, Kaohsiung, Taiwan
| | - Da-Ji Huang
- Department of Environmental Resources Management, Chia Nan University of Pharmacy & Science, Tainan, Taiwan
| | - Chih-Ching Chien
- Graduate School of Biotechnology and Bioengineering, Yuan Ze University, Chung-Li, Taiwan
| | - Ssu-Ching Chen
- Department of Life Sciences, National Central University, Taoyuan, Taiwan
| | | | - Chien-Cheng Chen
- Department of Biotechnology, National Kaohsiung Normal University, Kaohsiung, Taiwan.
| |
Collapse
|
12
|
Jiang M, Lin H, Yin J, Wang Z, Pang H, Huang R, Du L. [Characterization and molecular modification of β-glucosidase from Citrobacter koser GXW-1]. Wei Sheng Wu Xue Bao 2017; 57:363-374. [PMID: 29756435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
OBJECTIVE The aim of this study was to characterize β-glucosidase from Citrobacter koser GXW-1 isolated from soil and to improve the enzyme by molecular modification. MEHODS A bacterial strain with β-glucosidase activity was screened from the soil around Wuming sugar mill in Guangxi by esculin-ferric ammonium citrate selecting plate. The 16S rDNA of the strain was obtained and analyzed. By searching GenBank database, the genes encoding β-glucosidase from the same genus Citrobacter were found. These sequences were aligned. Then, a gene encoding β-glucosidase was amplified by PCR. The recombinant plasmid pQE-cbgl was constructed. The recombinant protein was purified with Ni-NTA. The enzyme properties of the recombinant protein CBGL were studied in detail. At last, the wild enzyme CBGL was reformed by error-prone PCR and site-directed random mutagenesis. RESULTS C. koser GXW-1 with β-glucosidase activity was isolated from the soil. A gene encoding β-glucosidase was cloned from the wild strain GXW-1. The properties of CBGL were identified. Its optimal pH and temperature were 6.0 and 45℃. Its Km and Vmax value were (11.280±1.073) mmol/L and (0.1704±0.0073) μmol/(mg·min), respectively. Its Ki values was (66.84±3.40) mmol/L. CBGL can hydrolyze α-pNPG, stevioside, daidzin and genistin. CBGL was modified by error-prone PCR and site directed random mutagenesis. A positive mutant W147F was obtained successfully. Its Vmax was 2.54 times that of the wild enzyme CBGL. CONCLUSION CBGL not only can hydrolyze β-glycosidic bond, but also can hydrolyze the α-glycosidic bond in α-pNPG. Furthermore, CBGL can hydrolyze stevioside, daidzin and genistin. These characteristics indicate that the β-glucosidase CBGL has important applications in theoretical research and in industry.
Collapse
|
13
|
Xu L, Huo M, Sun C, Cui X, Zhou D, Crittenden JC, Yang W. Bioresources inner-recycling between bioflocculation of Microcystis aeruginosa and its reutilization as a substrate for bioflocculant production. Sci Rep 2017; 7:43784. [PMID: 28252111 PMCID: PMC5333146 DOI: 10.1038/srep43784] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 01/30/2017] [Indexed: 11/09/2022] Open
Abstract
Bioflocculation, being environmental-friendly and highly efficient, is considered to be a promising method to harvest microalgae. However, one limitation of this technology is high expense on substrates for bioflocculant bacteria cultivation. In this regard, we developed an innovative method for the inner-recycling of biomass that could harvest the typical microalgae, Microcystis aeruginosa, using a bioflocculant produced by Citrobacter sp. AzoR-1. In turn, the flocculated algal biomass could be reutilized as a substrate for Citrobacter sp. AzoR-1 cultivation and bioflocculant production. The experimental results showed that 3.4 ± 0.1 g of bioflocculant (hereafter called MBF-12) was produced by 10 g/L of wet biomass of M. aeruginosa (high-pressure steam sterilized) with an additional 10 g/L of glucose as an extra carbon source. The efficiency of MBF-12 for M. aeruginosa harvesting could reach ~95% under the optimized condition. Further analysis showed that MBF-12, dominated by ~270 kDa biopolymers, contributed the bioflocculation mechanisms of interparticle bridging and biosorption process. Bioflocculant synthesis by Citrobacter sp. AzoR-1 using microalga as a substrate, including the polyketide sugar unit, lipopolysaccharide, peptidoglycan and terpenoid backbone pathways. Our research provides the first evidence that harvested algae can be reutilized as a substrate to grow a bioflocculant using Citrobacter sp. AzoR-1.
Collapse
Affiliation(s)
- Liang Xu
- School of Environment, Northeast Normal University, Changchun 130117, China
- Jilin Institute of Chemical Technology, Jilin, 132022, China
| | - Mingxin Huo
- School of Environment, Northeast Normal University, Changchun 130117, China
| | - Caiyun Sun
- School of Environment, Northeast Normal University, Changchun 130117, China
| | - Xiaochun Cui
- School of Environment, Northeast Normal University, Changchun 130117, China
| | - Dandan Zhou
- School of Environment, Northeast Normal University, Changchun 130117, China
| | - John C. Crittenden
- Brook Byers Institute for Sustainable Systems, and School of Civil & Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Wu Yang
- School of Environment, Northeast Normal University, Changchun 130117, China
| |
Collapse
|
14
|
Sun Q, Li ZL, Wang YZ, Yang CX, Chung JS, Wang AJ. Cathodic bacterial community structure applying the different co-substrates for reductive decolorization of Alizarin Yellow R. Bioresour Technol 2016; 208:64-72. [PMID: 26922314 DOI: 10.1016/j.biortech.2016.02.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Revised: 01/31/2016] [Accepted: 02/01/2016] [Indexed: 06/05/2023]
Abstract
Selective enrichment of cathodic bacterial community was investigated during reductive decolorization of AYR fedding with glucose or acetate as co-substrates in biocathode. A clear distinction of phylotype structures were observed between glucose-fed and acetate-fed biocathodes. In glucose-fed biocathode, Citrobacter (29.2%), Enterococcus (14.7%) and Alkaliflexus (9.2%) were predominant, and while, in acetate-fed biocathode, Acinetobacter (17.8%) and Achromobacter (6.4%) were dominant. Some electroactive or reductive decolorization genera, like Pseudomonas, Delftia and Dechloromonas were commonly enriched. Both of the higher AYR decolorization rate (k(AYR)=0.46) and p-phenylenediamine (PPD) generation rate (k(PPD)=0.38) were obtained fed with glucose than acetate (k(AYR)=0.18; k(PPD)=0.16). The electrochemical behavior analysis represented a total resistance in glucose-fed condition was about 73.2% lower than acetate-fed condition. The different co-substrate types, resulted in alteration of structure, richness and composition of bacterial communities, which significantly impacted the performances and electrochemical behaviors during reductive decolorization of azo dyes in biocathode.
Collapse
Affiliation(s)
- Qian Sun
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology (SKLUWRE, HIT), No. 73 Huanghe Road, Harbin 150090, PR China
| | - Zhi-Ling Li
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology (SKLUWRE, HIT), No. 73 Huanghe Road, Harbin 150090, PR China
| | - You-Zhao Wang
- School of Mechanical Engineering and Automation, Northeastern University, Shenyang 110004, PR China
| | - Chun-Xue Yang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology (SKLUWRE, HIT), No. 73 Huanghe Road, Harbin 150090, PR China
| | - Jong Shik Chung
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), San 31, Hyoja-dong, Pohang 790-784, South Korea; Division of Environmental Catalysis, Research Institute of Industrial Science and Technology, P.O. Box 135, Pohang 790-600, South Korea
| | - Ai-Jie Wang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology (SKLUWRE, HIT), No. 73 Huanghe Road, Harbin 150090, PR China; Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, PR China.
| |
Collapse
|
15
|
Al-Ghouti MA, Abuqaoud RH, Abu-Dieyeh MH. Detoxification of mercury pollutant leached from spent fluorescent lamps using bacterial strains. Waste Manag 2016; 49:238-244. [PMID: 26725036 DOI: 10.1016/j.wasman.2015.12.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2015] [Revised: 12/13/2015] [Accepted: 12/15/2015] [Indexed: 06/05/2023]
Abstract
The spent fluorescent lamps (SFLs) are being classified as a hazardous waste due to having mercury as one of its main components. Mercury is considered the second most toxic heavy metal (arsenic is the first) with harmful effects on animal nervous system as it causes different neurological disorders. In this research, the mercury from phosphor powder was leached, then bioremediated using bacterial strains isolated from Qatari environment. Leaching of mercury was carried out with nitric and hydrochloric acid solutions using two approaches: leaching at ambient conditions and microwave-assisted leaching. The results obtained from this research showed that microwave-assisted leaching method was significantly better in leaching mercury than the acid leaching where the mercury leaching efficiency reached 76.4%. For mercury bio-uptake, twenty bacterial strains (previously isolated and purified from petroleum oil contaminated soils) were sub-cultured on Luria Bertani (LB) plates with mercury chloride to check the bacterial tolerance to mercury. Seven of these twenty strains showed a degree of tolerance to mercury. The bio-uptake capacities of the promising strains were investigated using the mercury leached from the fluorescent lamps. Three of the strains (Enterobacter helveticus, Citrobacter amalonaticus, and Cronobacter muytjensii) showed bio-uptake efficiency ranged from 28.8% to 63.6%.
Collapse
Affiliation(s)
- Mohammad A Al-Ghouti
- Department of Biological and Environmental Sciences, College of Arts and Sciences, Qatar University, P.O. Box: 2713, Doha, Qatar
| | - Reem H Abuqaoud
- Department of Biological and Environmental Sciences, College of Arts and Sciences, Qatar University, P.O. Box: 2713, Doha, Qatar
| | - Mohammed H Abu-Dieyeh
- Department of Biological and Environmental Sciences, College of Arts and Sciences, Qatar University, P.O. Box: 2713, Doha, Qatar.
| |
Collapse
|
16
|
Shevtsov MB, Streeter SD, Thresh SJ, Swiderska A, McGeehan JE, Kneale GG. Structural analysis of DNA binding by C.Csp231I, a member of a novel class of R-M controller proteins regulating gene expression. Acta Crystallogr D Biol Crystallogr 2015; 71:398-407. [PMID: 25664751 PMCID: PMC4321490 DOI: 10.1107/s139900471402690x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Accepted: 12/08/2014] [Indexed: 01/03/2023]
Abstract
In a wide variety of bacterial restriction-modification systems, a regulatory `controller' protein (or C-protein) is required for effective transcription of its own gene and for transcription of the endonuclease gene found on the same operon. We have recently turned our attention to a new class of controller proteins (exemplified by C.Csp231I) that have quite novel features, including a much larger DNA-binding site with an 18 bp (∼60 Å) spacer between the two palindromic DNA-binding sequences and a very different recognition sequence from the canonical GACT/AGTC. Using X-ray crystallography, the structure of the protein in complex with its 21 bp DNA-recognition sequence was solved to 1.8 Å resolution, and the molecular basis of sequence recognition in this class of proteins was elucidated. An unusual aspect of the promoter sequence is the extended spacer between the dimer binding sites, suggesting a novel interaction between the two C-protein dimers when bound to both recognition sites correctly spaced on the DNA. A U-bend model is proposed for this tetrameric complex, based on the results of gel-mobility assays, hydrodynamic analysis and the observation of key contacts at the interface between dimers in the crystal.
Collapse
Affiliation(s)
- M. B. Shevtsov
- Biophysics Laboratories, Institute of Biomedical and Biomolecular Sciences, School of Biological Sciences, University of Portsmouth, Portsmouth PO1 2DY, England
| | - S. D. Streeter
- Biophysics Laboratories, Institute of Biomedical and Biomolecular Sciences, School of Biological Sciences, University of Portsmouth, Portsmouth PO1 2DY, England
| | - S.-J. Thresh
- Biophysics Laboratories, Institute of Biomedical and Biomolecular Sciences, School of Biological Sciences, University of Portsmouth, Portsmouth PO1 2DY, England
| | - A. Swiderska
- Biophysics Laboratories, Institute of Biomedical and Biomolecular Sciences, School of Biological Sciences, University of Portsmouth, Portsmouth PO1 2DY, England
| | - J. E. McGeehan
- Biophysics Laboratories, Institute of Biomedical and Biomolecular Sciences, School of Biological Sciences, University of Portsmouth, Portsmouth PO1 2DY, England
| | - G. G. Kneale
- Biophysics Laboratories, Institute of Biomedical and Biomolecular Sciences, School of Biological Sciences, University of Portsmouth, Portsmouth PO1 2DY, England
| |
Collapse
|
17
|
Mnif I, Fendri R, Ghribi D. Malachite green bioremoval by a newly isolated strain Citrobacter sedlakii RI11; enhancement of the treatment by biosurfactant addition. Water Sci Technol 2015; 72:1283-1293. [PMID: 26465297 DOI: 10.2166/wst.2015.302] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Citrobacter sedlackii RI11, isolated from acclimated textile effluent after selective enrichment on synthetic dyes, was assessed for malachite green (MG) biotreatment potency. Results indicate that this bacterium has potential for use in effective treatment of MG contaminated wastewaters under shaking conditions at neutral and alkaline pH value, characteristic of typical textile effluents. Also, the newly isolated strain can tolerate higher doses of dye and decolorize up to 1,000 mg/l of dye. When used as microbial surfactant to enhance MG biodecolorization, Bacillus subtilis SPB1-derived lipopeptide accelerated the decolorization rate and maximized the decolorization efficiency at an optimal concentration of biosurfactant of about 0.075%. Studies ensured that MG removal by this strain could be due to biodegradation and/or adsorption. Results on germination potencies of different seeds using the treated dyes under different conditions favor the use of SPB1 biosurfactant for the treatment of MG.
Collapse
Affiliation(s)
- Inès Mnif
- Unité 'Enzymes et Bioconversion', National School of Engineers of Sfax, Université de Sfax, BP W 3038 Sfax, Tunisia and Higher Institute of Biotechnology of Sfax, Université de Sfax, Tunisia E-mail:
| | - Raouia Fendri
- Unité 'Enzymes et Bioconversion', National School of Engineers of Sfax, Université de Sfax, BP W 3038 Sfax, Tunisia and Higher Institute of Biotechnology of Sfax, Université de Sfax, Tunisia E-mail:
| | - Dhouha Ghribi
- Unité 'Enzymes et Bioconversion', National School of Engineers of Sfax, Université de Sfax, BP W 3038 Sfax, Tunisia and Higher Institute of Biotechnology of Sfax, Université de Sfax, Tunisia E-mail:
| |
Collapse
|
18
|
Li F, Zhu L, Zhang D. Effect of surfactant on phenanthrene metabolic kinetics by Citrobacter sp. SA01. J Environ Sci (China) 2014; 26:2298-2306. [PMID: 25458685 DOI: 10.1016/j.jes.2014.09.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Revised: 04/30/2014] [Accepted: 06/09/2014] [Indexed: 06/04/2023]
Abstract
To attain a better understanding of the effects of surfactants on the metabolic kinetics of hydrophobic organic compounds, the biodegradation of phenanthrene by Citrobacter sp. SA01 was investigated in a batch experiment containing Tween 80, sodium dodecyl benzene sulfonate and liquid mineral salt medium. The Monod model was modified to effectively describe the partition, phenanthrene biodegradation and biopolymer production. The results showed that Tween 80 and sodium dodecyl benzene sulfonate (each at 50mg/L) enhanced phenanthrene metabolism and poly-β-hydroxybutyrate production as indicated by the increasing amounts of intermediates (by 17.2% to 47.9%), and percentages of poly-β-hydroxybutyrate (by 107.3% and 33.1%) within the cell dry weight when compared to their absence. The modified Monod model was capable of predicting microbial growth, phenanthrene depletion and biopolymer production. Furthermore, the Monod kinetic coefficients were largely determined by the surfactant-enhanced partition, suggesting that partitioning is a critical process in surfactant-enhanced bioremediation of hydrophobic organic compounds.
Collapse
Affiliation(s)
- Feng Li
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Organic Pollution Process Control, Hangzhou 310058, China; Zhejiang Yuying College, Hangzhou 310018, China.
| | - Lizhong Zhu
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Organic Pollution Process Control, Hangzhou 310058, China.
| | - Dong Zhang
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Organic Pollution Process Control, Hangzhou 310058, China
| |
Collapse
|
19
|
Li F, Zhu L. Surfactant-modified fatty acid composition of Citrobacter sp. SA01 and its effect on phenanthrene transmembrane transport. Chemosphere 2014; 107:58-64. [PMID: 24875871 DOI: 10.1016/j.chemosphere.2014.03.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2013] [Revised: 02/13/2014] [Accepted: 03/01/2014] [Indexed: 06/03/2023]
Abstract
The effects of the surfactants, Tween 80 and sodium dodecyl benzene sulfonate (SDBS) on a membrane's fatty acid composition and the transmembrane transport of phenanthrene were investigated. The results indicated that both surfactants could modify the composition of fatty acids of Citrobacter sp. Strain SA01 cells, 50 mg L(-1) of both surfactants changed the composition of the fatty acids the most, increasing the amount of unsaturated fatty acids. The comparison of fatty acid profiles with diphenylhexatriene fluorescence anisotropy, a probe for plasma membrane fluidity, suggested that an increased amount of unsaturated fatty acids corresponded to greater membrane fluidity. In addition, increased unsaturated fatty acids promoted phenanthrene to partition from the extracellular matrix to cell debris, which increased reverse partitioning from the cell debris to the cytochylema. The results of this study were expected in that the addition of a surfactant is a simple and effective method for accelerating the rate-limiting step of transmembrane transport of hydrophobic organic compounds (HOCs) in bioremediation.
Collapse
Affiliation(s)
- Feng Li
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Organic Pollution Process Control, Hangzhou 310058, China; Zhejiang Yuying College, Hangzhou 310018, China
| | - Lizhong Zhu
- Department of Environmental Science, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Organic Pollution Process Control, Hangzhou 310058, China.
| |
Collapse
|
20
|
Mandal SM, Sharma S, Pinnaka AK, Kumari A, Korpole S. Isolation and characterization of diverse antimicrobial lipopeptides produced by Citrobacter and Enterobacter. BMC Microbiol 2013; 13:152. [PMID: 23834699 PMCID: PMC3716907 DOI: 10.1186/1471-2180-13-152] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Accepted: 07/03/2013] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Increasing multidrug-resistance in bacteria resulted in a greater need to find alternative antimicrobial substances that can be used for clinical applications or preservation of food and dairy products. Research on antimicrobial peptides including lipopeptides exhibiting both narrow and broad spectrum inhibition activities is increasing in the recent past. Therefore, the present study was aimed at isolation and characterization of antimicrobial lipopeptide producing bacterial strains from fecal contaminated soil sample. RESULTS The phenotypic and 16S rRNA gene sequence analysis of all isolates identified them as different species of Gram-negative genera Citrobacter and Enterobacter. They exhibited common phenotypic traits like citrate utilization, oxidase negative and facultative anaerobic growth. The HPLC analysis of solvent extracts obtained from cell free fermented broth revealed the presence of multiple antimicrobial lipopeptides. The comprehensive mass spectral analysis (MALDI-TOF MS and GC-MS) of HPLC purified fractions of different isolates revealed that the lipopeptides varied in their molecular weight between (m/z) 607.21 to 1536.16 Da. Isomers of mass ion m/z 984/985 Da was produced by all strains. The 1495 Da lipopeptides produced by strains S-3 and S-11 were fengycin analogues and most active against all strains. While amino acid analysis of lipopeptides suggested most of them had similar composition as in iturins, fengycins, kurstakins and surfactins, differences in their β-hydroxy fatty acid content proposed them to be isoforms of these lipopeptides. CONCLUSION Although antimicrobial producing strains can be used as biocontrol agents in food preservation, strains with ability to produce multiple antimicrobial lipopeptides have potential applications in biotechnology sectors such as pharmaceutical and cosmetic industry. This is the first report on antibacterial lipopeptides production by strains of Citrobacter and Enterobacter.
Collapse
Affiliation(s)
- Santi M Mandal
- Central Research Facility, Indian Institute of Technology Kharagpur, Kharagpur-721302, West Bengal, India
| | - Shalley Sharma
- MTCC and Gene Bank, CSIR-Institute of Microbial Technology, Sector 39A, Chandigarh 160036, India
| | - Anil Kumar Pinnaka
- MTCC and Gene Bank, CSIR-Institute of Microbial Technology, Sector 39A, Chandigarh 160036, India
| | - Annu Kumari
- MTCC and Gene Bank, CSIR-Institute of Microbial Technology, Sector 39A, Chandigarh 160036, India
| | - Suresh Korpole
- MTCC and Gene Bank, CSIR-Institute of Microbial Technology, Sector 39A, Chandigarh 160036, India
| |
Collapse
|
21
|
Chandrashekhar B, Pai P, Morone A, Sahu N, Pandey RA. Reduction of NOx in Fe-EDTA and Fe-NTA solutions by an enriched bacterial population. Bioresour Technol 2013; 130:644-651. [PMID: 23334022 DOI: 10.1016/j.biortech.2012.12.051] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Revised: 12/07/2012] [Accepted: 12/08/2012] [Indexed: 06/01/2023]
Abstract
An enriched biomass was developed from municipal sewage sludge consisting of three dominant bacteria, representing the genera of Enterobacter, Citrobacter and Streptomyces. The biomass was used in a series of batch experiments in order to determine kinetic constants associated with biomass growth and NOx reduction in aqueous Ferrous EDTA/NTA solutions and Ferric EDTA/NTA solutions using ethanol as organic electron donor. The maximum specific reduction rates of NOx in Ferrous EDTA and Ferrous NTA solutions were 0.037 and 0.047mMolesL(-1)d(-1)mg(-1) biomass, respectively while in Ferric EDTA and Ferric NTA solutions were 0.022 and 0.024mMolesL(-1)d(-1)mg(-1) biomass, respectively. In case of Ferric EDTA/NTA solution, the kinetic constants associated with reduction of Ferric EDTA/NTA to Ferrous EDTA/NTA were also evaluated simultaneously. The maximum specific reduction rates of Ferric EDTA and Ferric NTA were 0.0021 and 0.0026mMolesL(-1)d(-1)mg(-1) biomass. The significance of these observations are presented and discussed in this paper.
Collapse
Affiliation(s)
- B Chandrashekhar
- Environmental Biotechnology Division, National Environmental Engineering Research Institute, Nehru Marg, Nagpur 440020, India
| | | | | | | | | |
Collapse
|
22
|
Chan GF, Rashid NAA, Chua LS, Ab llah N, Nasiri R, Ikubar MRM. Communal microaerophilic-aerobic biodegradation of Amaranth by novel NAR-2 bacterial consortium. Bioresour Technol 2012; 105:48-59. [PMID: 22182471 DOI: 10.1016/j.biortech.2011.11.094] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2011] [Revised: 11/15/2011] [Accepted: 11/24/2011] [Indexed: 05/27/2023]
Abstract
A novel bacterial consortium, NAR-2 which consists of Citrobacter freundii A1, Enterococcus casseliflavus C1 and Enterobacter cloacae L17 was investigated for biodegradation of Amaranth azo dye under sequential microaerophilic-aerobic condition. The NAR-2 bacterial consortium with E. casseliflavus C1 as the dominant strain enhanced the decolorization process resulting in reduction of Amaranth in 30 min. Further aerobic biodegradation, which was dominated by C. freundii A1 and E. cloacae L17, allowed biotransformation of azo reduction intermediates and mineralization via metabolic pathways including benzoyl-CoA, protocatechuate, salicylate, gentisate, catechol and cinnamic acid. The presence of autoxidation products which could be metabolized to 2-oxopentenoate was elucidated. The biodegradation mechanism of Amaranth by NAR-2 bacterial consortium was predicted to follow the steps of azo reduction, deamination, desulfonation and aromatic ring cleavage. This is for the first time the comprehensive microaerophilic-aerobic biotransformation pathways of Amaranth dye intermediates by bacterial consortium are being proposed.
Collapse
Affiliation(s)
- Giek Far Chan
- Nanoporous Materials for Biological Application Research Group (NAMBAR), Sustainability Research Alliance, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor, Malaysia.
| | | | | | | | | | | |
Collapse
|
23
|
Mohite BV, Pawar SP, Morankar A. Isolation, selection and biodegradation profile of phenol degrading bacteria from oil contaminated soil. Bull Environ Contam Toxicol 2011; 87:143-6. [PMID: 21643832 DOI: 10.1007/s00128-011-0322-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2010] [Accepted: 05/25/2011] [Indexed: 05/21/2023]
Abstract
In the present study, an aerobic bacterial strains OCS-A and OCS- B were isolated from an oil contaminated soil. The strains were identified to be Citrobacter freundi and Proteus mirabilis according to morphological, physiological and biochemical characteristics. The strains were able to degrade about 90% of 100 mg/L phenol within 80 h as sole carbon and energy source. The lag phase increased with increase in phenol concentration. Determination of metabolic intermediate 2-HMS, was done which indicate meta-cleavage pathway of phenol metabolism. Hence these isolates can be effectively used for bioremediation of phenol contaminated sites.
Collapse
|
24
|
McGeehan J, Streeter S, Thresh SJ, Taylor J, Shevtsov M, Kneale G. Structural analysis of a novel class of R-M controller proteins: C.Csp231I from Citrobacter sp. RFL231. J Mol Biol 2011; 409:177-88. [PMID: 21440553 PMCID: PMC3115060 DOI: 10.1016/j.jmb.2011.03.033] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2011] [Revised: 03/14/2011] [Accepted: 03/16/2011] [Indexed: 11/22/2022]
Abstract
Controller proteins play a key role in the temporal regulation of gene expression in bacterial restriction-modification (R-M) systems and are important mediators of horizontal gene transfer. They form the basis of a highly cooperative, concentration-dependent genetic switch involved in both activation and repression of R-M genes. Here we present biophysical, biochemical, and high-resolution structural analysis of a novel class of controller proteins, exemplified by C.Csp231I. In contrast to all previously solved C-protein structures, each protein subunit has two extra helices at the C-terminus, which play a large part in maintaining the dimer interface. The DNA binding site of the protein is also novel, having largely AAAA tracts between the palindromic recognition half-sites, suggesting tight bending of the DNA. The protein structure shows an unusual positively charged surface that could form the basis for wrapping the DNA completely around the C-protein dimer.
Collapse
Affiliation(s)
- J.E. McGeehan
- Biophysics Laboratories, Institute of Biomedical and Biomolecular Sciences, School of Biological Sciences, University of Portsmouth, Portsmouth PO1 2DY, UK
| | | | | | | | | | - G.G. Kneale
- Biophysics Laboratories, Institute of Biomedical and Biomolecular Sciences, School of Biological Sciences, University of Portsmouth, Portsmouth PO1 2DY, UK
| |
Collapse
|
25
|
Hiligsmann S, Masset J, Hamilton C, Beckers L, Thonart P. Comparative study of biological hydrogen production by pure strains and consortia of facultative and strict anaerobic bacteria. Bioresour Technol 2011; 102:3810-3818. [PMID: 21185171 DOI: 10.1016/j.biortech.2010.11.094] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2010] [Revised: 11/21/2010] [Accepted: 11/22/2010] [Indexed: 05/30/2023]
Abstract
In this paper, a simple and rapid method was developed in order to assess in comparative tests the production of binary biogas mixtures containing CO(2) and another gaseous compound such as hydrogen or methane. This method was validated and experimented for the characterisation of the biochemical hydrogen potential of different pure strains and mixed cultures of hydrogen-producing bacteria (HPB) growing on glucose. The experimental results compared the hydrogen production yield of 19 different pure strains and sludges: facultative and strict anaerobic HPB strains along with anaerobic digester sludges thermally pre-treated or not. Significant yields variations were recorded even between different strains of the same species by i.e. about 20% for three Clostridium butyricum strains. The pure Clostridium butyricum and pasteurianum strains achieved the highest yields i.e. up to 1.36 mol H(2)/mol glucose compared to the yields achieved by the sludges and the tested Escherichia and Citrobacter strains.
Collapse
Affiliation(s)
- Serge Hiligsmann
- Walloon Centre of Industrial Biology (CWBI), Bd du Rectorat, 29, B.40 - P.70, B-4000 Liege, Belgium.
| | | | | | | | | |
Collapse
|
26
|
Van Nevel S, Hennebel T, Verschuere S, De Corte S, Boon N, Verstraete W. Palladium nanoparticles produced by fermentatively grown bacteria as catalyst for diatrizoate removal with biogenic hydrogen. Commun Agric Appl Biol Sci 2011; 76:185-188. [PMID: 21539227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Affiliation(s)
- S Van Nevel
- Laboratory of Microbial Ecology and Technology, Ghent University, Coupure Links 653, B-9000 Gent, Belgium
| | | | | | | | | | | |
Collapse
|
27
|
Oh YK, Park S, Seol EH, Kim SH, Kim MS, Hwang JW, Ryu DDY. Carbon and energy balances of glucose fermentation with hydrogenproducing bacterium Citrobacter amalonaticus Y19. J Microbiol Biotechnol 2008; 18:532-538. [PMID: 18388473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
For the newly isolated H2-producing chemoheterotrophic bacterium Citrobacter amalonaticus Y19, anaerobic glucose metabolism was studied in batch cultivation at varying initial glucose concentrations (3.5- 9.5 g/l). The carbon-mass and energy balances were determined and utilized to analyze the carbon metabolic-pathways network. The analyses revealed (a) variable production of major metabolites (H2, ethanol, acetate, lactate, CO2, and cell mass) depending on initial glucose levels; (b) influence of NADH regeneration on the production of acetate, lactate, and ethanol; and (c) influence of the molar production of ATP on the production of biomass. The results reported in this paper suggest how the carbon metabolic pathway(s) should be designed for optimal H2 production, especially at high glucose concentrations, such as by blocking the carbon flux via lactate dehydrogenase from the pyruvate node.
Collapse
Affiliation(s)
- You-Kwan Oh
- Bioenergy Research Center, Korea Institute of Energy Research, Daejeon 305-543, Korea
| | | | | | | | | | | | | |
Collapse
|
28
|
Selvakumaran S, Kapley A, Kalia VC, Purohit HJ. Phenotypic and phylogenic groups to evaluate the diversity of Citrobacter isolates from activated biomass of effluent treatment plants. Bioresour Technol 2008; 99:1189-95. [PMID: 17475485 DOI: 10.1016/j.biortech.2007.02.021] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2006] [Revised: 02/15/2007] [Accepted: 02/15/2007] [Indexed: 05/15/2023]
Abstract
The diversity of Citrobacter isolated from effluent treatment plants (ETPs) was studied using three different parameters. Thirty Citrobacter strains were isolated from different ETPs treating wastewaters generated at various industries. All the isolates were characterized based on biochemical tests, antibiotic assay/functional analysis, and phylogenetic analysis. Results demonstrated that the pattern of grouping varied based on the selected criteria for analysis. Species that clustered together by biochemical analysis were found to vary by functional and 16S rDNA analysis and vice versa. This suggests that multiple methods approach needs to be carried out to understand the microbial diversity. Bacteria in effluent treatment plants are exposed to diverse categories of pollutants. Salicylate is a key intermediate formed during biodegradation of several aromatic compounds, a scenario expected in ETPs. Hence, the Citrobacter isolates were screened for their capability to utilize salicylate. In future studies, these isolates can be incorporated in a bioremediation program.
Collapse
Affiliation(s)
- S Selvakumaran
- Environmental Genomics Unit, National Environmental Engineering Research Institute, CSIR, Nehru Marg, Nagpur 440 020, MS, India
| | | | | | | |
Collapse
|
29
|
Xie S, Yang J, Chen C, Zhang X, Wang Q, Zhang C. Study on biosorption kinetics and thermodynamics of uranium by Citrobacter freudii. J Environ Radioact 2008; 99:126-33. [PMID: 17765369 DOI: 10.1016/j.jenvrad.2007.07.003] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2007] [Revised: 06/30/2007] [Accepted: 07/09/2007] [Indexed: 05/17/2023]
Abstract
Biosorption has been developed as an effective and economic method to treat wastewater containing low concentrations of metal pollutants. In this study, a bacterium, Citrobacter freudii, was used as a biosorbent to adsorb uranium ions. The thermodynamics and kinetics of this adsorption, as well as its mechanism, were investigated. The results indicated that the biosorption rate could be better described by a pseudo 2nd-order model than a pseudo 1st-order model. The adsorption of U (VI) proceeded very rapidly in the first 30min and subsequently slowed down continuously for a long period. The biosorption isotherm of uranium by C. freudii could be described well by the Langmuir or Freundlich isotherm, and the latter was better. The thermodynamics parameters, DeltaH degrees , DeltaG degrees , and DeltaS degrees were calculated according to the results of the experiment, which showed this biosorption as being endothermic and spontaneous. The authors investigated the active sites of bacteria for biosorption and the results proved that carboxyl in the cell wall played an important role in biosorption.
Collapse
Affiliation(s)
- Shuibo Xie
- Department of Environment Science and Engineering, Tsinghua University, Beijing 100084, P R China.
| | | | | | | | | | | |
Collapse
|
30
|
Hong YG, Guo J, Wang MN, Xu MY, Sun GP. [Isolation, identification and characterization of a broad-spectrum azo-reducing Citrobacter strain AzoR-2]. Huan Jing Ke Xue 2007; 28:1397-403. [PMID: 17674757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
A broad-spectrum azo-reducing bacterial strain, AzoR-2, was isolated from a active-sludge of textile-printing wastewater treatment plant and the strain was identified and characterized. This strain was identified as Citrobacter sp. according to its morphological, physiobiochemical characteristics and analysis of its 16S rDNA and beta-lactamase gene sequence. Studies showed that strain AzoR-2 was able to reduce various azo dyes with several organic substances and H2 as electron donor and the electrons for azoreduction came from primary electron donor. The azoreduction by strain AzoR-2 was inhibited strongly by O2. The enzyme system for azoreduction of strain AzoR-2 was located on cellular membrane, suggesting that the microbial azoreduction is linked to electron transport chain. Azoreduction by strain AzoR-2 was occurred in the range of alkaline pH at the temperature range 20 - 40 degrees C with optimum pH 7.5 and 35 degrees C. Azo-reducing Citrobacter bacterium may play important roles in bioremediation of the environment contaminated by azo dyes and in the decolorization of textile-printing wastewater.
Collapse
Affiliation(s)
- Yi-Guo Hong
- South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China.
| | | | | | | | | |
Collapse
|
31
|
Whittaker P, Keys CE, Brown EW, Fry FS. Differentiation of Enterobacter sakazakii from closely related Enterobacter and Citrobacter species using fatty acid profiles. J Agric Food Chem 2007; 55:4617-23. [PMID: 17472390 DOI: 10.1021/jf070193a] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Capillary gas chromatography with flame ionization detection (GC-FID) was used to determine the cellular fatty acid (CFA) profiles of 134 Enterobacter sakazakii strains, and these were compared to the CFA profiles of other closely related Enterobacter and Citrobacter species. For GC-FID analysis, whole cell fatty acid methyl esters (FAMEs) from cells cultured on brain heart infusion (BHI) agar at 37 degrees C for 24 h were obtained by saponification, methylation, and extraction into hexane/methyl tert-butyl ether. A database for E. sakazakii was prepared using fatty acid profiles from the 134 strains. Major fatty acids of E. sakazakii strains evaluated in this study were straight-chain 12:0, 14:0, and 16:0, unsaturated 18:1 omega7c, and 17:0 omegacyclo 7-8. Principal component analysis (PCA) based on CFA profiles for E. sakazakii strains shows separation of E. sakazakii subgroups A and B. The CFA profiles for E. sakazakii and Enterobacter cloacae show that there are several fatty acids, 14:0, 17:0 omegacyclo 7-8, 18:1 omega7c, and summed 16:1 omega6c/16:1 omega7c, that differ significantly between these two species. A PCA model based on CFA profiles for E. sakazakii strains clearly shows separation of E. sakazakii from closely related Enterobacter and Citrobacter species. Analysis of FAMEs from E. sakazakii strains grown on BHI agar by a rapid GC-FID method can provide a sensitive procedure for the identification of this organism, and this analytical method provides a confirmatory procedure for the differentiation of E. sakazakii strains from closely related Enterobacter and Citrobacter species.
Collapse
Affiliation(s)
- Paul Whittaker
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, Maryland 20740-3835, USA.
| | | | | | | |
Collapse
|
32
|
Kim LS, Hong SJ, Son MK, Lee YH. Polymeric and compositional properties of novel extracellular microbial polyglucosamine biopolymer from new strain of citrobacter sp. BL-4. Biotechnol Lett 2006; 28:241-5. [PMID: 16555007 DOI: 10.1007/s10529-005-5525-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2005] [Revised: 11/16/2005] [Accepted: 11/16/2005] [Indexed: 11/26/2022]
Abstract
A novel polyglucosamine polymer, PGB-2, was produced extracellularly from a new strain Citrobacter sp. BL-4 using pH-stat fed batch cultivation. It was composed of 97.3% glucosamine and 2.7% rhamnose; its average molecular weight, solubility in 2% acetic acid and viscosity were 20 kDa, 5 g l(-1) and 2.9 cps, respectively. FT-IR and 1H NMR spectra of PGB-2 revealed a close identity with chitosan from crab shells.
Collapse
Affiliation(s)
- Lin-Su Kim
- Department of Genetic Engineering, College of Natural Sciences, Kyungpook National University, Daegu 702-701, S. Korea
| | | | | | | |
Collapse
|
33
|
Zhang Y, Frankenberger WT. Removal of selenate in river and drainage waters by Citrobacter braakii enhanced with zero-valent iron. J Agric Food Chem 2006; 54:152-6. [PMID: 16390192 DOI: 10.1021/jf058124o] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
A cost-effective remediation method is needed to remove selenium (Se) from Se-contaminated water. In this study, a selenate [Se(VI)]-reducing bacterium, Citrobacter braakii, that is capable of using molasses as a carbon source to reduce Se(VI) from natural river and drainage waters was isolated. During an 8-day experiment, 87-97% of the added Se(VI) in New River water and White River water, California, was reduced to elemental Se [Se(0)] or transformed to organic Se. In highly saline drainage water, removal of Se(VI) by C. braakii was limited, with 20% Se(VI) removal in a 7-day experiment. Addition of zero-valent iron (ZVI) into these waters along with C. braakii inoculation significantly enhanced the removal of Se(VI) and reduced the formation of organic Se. This study suggests that the combination of a bacterial treatment using inexpensive molasses and ZVI can effectively remove Se from natural river water and agricultural drainage waters.
Collapse
Affiliation(s)
- Yiqiang Zhang
- Department of Environmental Sciences, 2217 Geology Building, University of California, Riverside, California 92521-0424, USA
| | | |
Collapse
|
34
|
Jang JH, Hia HC, Ike M, Inoue C, Fujita M, Yoshida T. Acid hydrolysis and quantitative determination of total hexosamines of an exopolysaccharide produced by Citrobacter sp. Biotechnol Lett 2005; 27:13-8. [PMID: 15685413 DOI: 10.1007/s10529-004-6305-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2004] [Accepted: 11/04/2004] [Indexed: 10/25/2022]
Abstract
During the hydrolysis of an exopolysaccharide (EPS) produced by Citrobacter sp., the maximum liberation of hexosamine was obtained with 6 M HCl at 115 degrees C in an autoclave for 1 h. The glycosidic bond energy and degree of acetylation of the hexosamine in EPS were approximately 77 kJ mol(-1) and 61%, respectively. Thermal destruction of the hexosamines and the effect of salt on the hexosamine determination could be minimized under the optimized hydrolytic conditions. Using a modified Elson-Morgan method, maximum total hexosamine concentration was determined to be 3.2 g l(-1) (29% of crude EPS) after 96 h of fed-batch culture.
Collapse
Affiliation(s)
- Jin-Ho Jang
- Department of Environmental Engineering, Graduate School of Engineering, Japan.
| | | | | | | | | | | |
Collapse
|
35
|
Kim JY, Lee YM, Jang MS, Kang DW, Kim SJ, Kim CH, Lee YC. Identification of genes required for decolorization of crystal violet in Citrobacter sp. MY-5. J GEN APPL MICROBIOL 2005; 51:191-5. [PMID: 16107757 DOI: 10.2323/jgam.51.191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Ji-Youn Kim
- Faculty of Biotechnology, College of Natural Resources and Life Science, Dong-A University, Busan, Korea
| | | | | | | | | | | | | |
Collapse
|
36
|
Gobert AP, Wilson KT, Martin C. Cellular responses to attaching and effacing bacteria: activation and implication of the innate immune system. Arch Immunol Ther Exp (Warsz) 2005; 53:234-44. [PMID: 15995584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2005] [Accepted: 02/04/2005] [Indexed: 05/03/2023]
Abstract
During the last decade, research on attaching-effacing (A/E) bacteria/host cell interactions has revealed much of the molecular basis of colonization and lesion formation. The colonic mucosa represents the first line of defense against these pathogens, and its integrity is required to avoid translocation of bacteria or bacterial soluble factors into the infected host. Therefore, the cellular immune response to A/E pathogens plays an important role in bacterial pathogenesis since it can clear the bacteria or modulate the inflammatory processes. Data obtained from infected patients demonstrate a correlation between the production of pro-inflammatory cytokines and the severity of the disease. In vitro studies of infected epithelial cells have clearly elucidated A/E bacteria-induced host signal transduction events. However, the identification of the bacterial factors responsible for cellular activation remains a subject of controversy. Experimental studies with knock-out mice infected with Citrobacter rodentium, a rodent A/E pathogen, indicate that innate immunity is an essential component of pathogenesis. This review summarizes in vivo and in vitro evidence for the induction and potential role of the innate immune system during infection with A/E bacteria.
Collapse
Affiliation(s)
- Alain P Gobert
- Unité de Microbiologie, Institut National de la Recherche Agronomique, Centre de Theix, 63122 Saint-Genés-Champanelle, France.
| | | | | |
Collapse
|
37
|
Prem Anand AA, Sripathi K. Digestion of cellulose and xylan by symbiotic bacteria in the intestine of the Indian flying fox (Pteropus giganteus). Comp Biochem Physiol A Mol Integr Physiol 2004; 139:65-9. [PMID: 15471682 DOI: 10.1016/j.cbpb.2004.07.006] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2004] [Revised: 06/30/2004] [Accepted: 07/01/2004] [Indexed: 11/29/2022]
Abstract
Bats (Order Chiroptera) are a widely distributed group of mammals. Pteropus giganteus belongs to the Suborder Megachiroptera. This bat consumes fruits and leaves as their major food. Cellulose and xylan are the major composition of leaves. As they consume leaves in their diet, their digestive tract must contain cellulolytic and xylanolytic bacteria which help in the digestion of cellulose and xylan. The cellulolytic and xylanolytic bacteria were isolated and screened on Berg's agar containing cellulose and xylan. The bacteria isolated were characterized biochemically and found to be Proteus vulgaris, Proteus mirabilis, Citrobacter freundii, Serratia liquefaciens and Klebsiella oxytoca. These bacteria help in digestion of cellulose and xylan in the diet of the bat, P. giganteus. Here we show that leaves are also used as a carbohydrate source by these bats. An insectivorous bat, Hipposideros fulvus, was used as a control and does not possess cellulolytic and xylanolytic bacteria.
Collapse
Affiliation(s)
- A Alwin Prem Anand
- Department of Animal Behaviour and Physiology, School of Biological Sciences, CAS in Functional Genomics, Madurai Kamaraj University, Madurai 625021, India
| | | |
Collapse
|
38
|
Luckarift HR, Dalton H, Sharma ND, Boyd DR, Holt RA. Isolation and characterisation of bacterial strains containing enantioselective DMSO reductase activity: application to the kinetic resolution of racemic sulfoxides. Appl Microbiol Biotechnol 2004; 65:678-85. [PMID: 15322772 DOI: 10.1007/s00253-004-1667-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2004] [Revised: 05/01/2004] [Accepted: 05/15/2004] [Indexed: 11/25/2022]
Abstract
The kinetic resolution of racemic sulfoxides by dimethyl sulfoxide (DMSO) reductases was investigated with a range of microorganisms. Three bacterial isolates (provisionally identified as Citrobacter braakii, Klebsiella sp. and Serratia sp.) expressing DMSO reductase activity were isolated from environmental samples by anaerobic enrichment with DMSO as terminal electron acceptor. The organisms reduced a diverse range of racemic sulfoxides to yield either residual enantiomer depending upon the strain used. C. braakii DMSO-11 exhibited wide substrate specificity that included dialkyl, diaryl and alkylaryl sulfoxides, and was unique in its ability to reduce the thiosulfinate 1,4-dihydrobenzo-2, 3-dithian-2-oxide. DMSO reductase was purified from the periplasmic fraction of C. braakii DMSO-11 and was used to demonstrate unequivocally that the DMSO reductase was responsible for enantiospecific reductive resolution of racemic sulfoxides.
Collapse
Affiliation(s)
- Heather R Luckarift
- Department of Biological Sciences, The University of Warwick, Coventry, CV4 7AL, UK.
| | | | | | | | | |
Collapse
|
39
|
Gruenheid S, Sekirov I, Thomas NA, Deng W, O'Donnell P, Goode D, Li Y, Frey EA, Brown NF, Metalnikov P, Pawson T, Ashman K, Finlay BB. Identification and characterization of NleA, a non-LEE-encoded type III translocated virulence factor of enterohaemorrhagic Escherichia coli O157:H7. Mol Microbiol 2004; 51:1233-49. [PMID: 14982621 DOI: 10.1046/j.1365-2958.2003.03911.x] [Citation(s) in RCA: 189] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Enterohaemorrhagic Escherichia coli (EHEC) O157:H7 uses a specialized protein translocation apparatus, the type III secretion system (TTSS), to deliver bacterial effector proteins into host cells. These effectors interfere with host cytoskeletal pathways and signalling cascades to facilitate bacterial survival and replication and promote disease. The genes encoding the TTSS and all known type III secreted effectors in EHEC are localized in a single pathogenicity island on the bacterial chromosome known as the locus for enterocyte effacement (LEE). In this study, we performed a proteomic analysis of proteins secreted by the LEE-encoded TTSS of EHEC. In addition to known LEE-encoded type III secreted proteins, such as EspA, EspB and Tir, a novel protein, NleA (non-LEE-encoded effector A), was identified. NleA is encoded in a prophage-associated pathogenicity island within the EHEC genome, distinct from the LEE. The LEE-encoded TTSS directs translocation of NleA into host cells, where it localizes to the Golgi apparatus. In a panel of strains examined by Southern blot and database analyses, nleA was found to be present in all other LEE-containing pathogens examined, including enteropathogenic E. coli and Citrobacter rodentium, and was absent from non-pathogenic strains of E. coli and non-LEE-containing pathogens. NleA was determined to play a key role in virulence of C. rodentium in a mouse infection model.
Collapse
Affiliation(s)
- Samantha Gruenheid
- Biotechnology Laboratory, University of British Columbia, Room 237, Wesbrook Building, 6174 University Boulevard, Vancouver, BC, V6T 1Z3, Canada
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
40
|
Hia HC, Jang JH, Ike M, Inoue C, Fujita M, Yoshida T. Improved borate method for the rapid distinction of glucosamine and galactosamine in an exopolysaccharide produced by Citrobacter sp. Biotechnol Lett 2004; 26:1307-11. [PMID: 15562551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
An improved borate method for the quantitative distinction of glucosamine (GlcN) and galactosamine (GalN) in a mixture is presented which is based on the Elson-Morgan method with addition of sodium borate to differentiate colour formation by the two hexosamines. The r2 value and maximum deviation of the method based on calculations derived in this study were 0.9979 and 5.1 %, respectively. Using this method, the GlcN/GalN ratio in an exopolysaccharide (EPS) produced by Citrobacter sp. was found to change with time during the production process, with a maximum value at 9.8:1.
Collapse
Affiliation(s)
- Hui Ching Hia
- Department of Environmental Engineering, Graduate School of Engineering, Osaka University, Suita city, Osaka, Japan
| | | | | | | | | | | |
Collapse
|
41
|
Abstract
To identify genes involved in the decolorization of malachite green, random mutants generated by transposon insertion in the malachite green-decolorizing bacterium, Citrobacter sp. were isolated. The resulting mutant bank yielded 24 mutants with complete defects in their abilities to decolorize malachite green. Southern hybridization with a Tn5 fragment as a probe showed a single hybridized band in 7 mutants, which appeared to have insertions at different sites of the chromosome. The Tn5-inserted genes were isolated and the DNA sequence flanking Tn5 was determined. Based on a sequence database, the putative protein products encoded by the mg genes were identified as follows. mg3, an ABC transporter homolog; mg6, a LysR-type regulatory protein; m11, an oxidoreductase; mg17, a MalG protein in the maltose transport system; and mg21, a sugar kinase. The deduced sequences from two mg genes (mg7 and mg18) showed no significant similarity to any protein with a known function, suggesting that these two mg genes encode unidentified proteins that are responsible for the decolorization of malachite green.
Collapse
Affiliation(s)
- Moon-Sun Jang
- Faculty of Biotechnology, College of Natural Resources and Life Science, Dong-A University, Busan 604-714, Korea
| | | | | | | | | | | |
Collapse
|
42
|
Jang MS, Lee YM, Choi YL, Cho YS, Lee YC. Isolation of Citrobacter sp. mutants defective in decolorization of brilliant green by transposon mutagenesis. J Microbiol 2004; 42:139-42. [PMID: 15357308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
Abstract
To identify genes involved in the decolorization of brilliant green, we isolated random mutants generated by transposon insertion in brilliant green-decolorizing bacterium, Citrobacter sp. The resulting mutant bank yielded 19 mutants with a complete defect in terms of the brilliant green color removing ability. Southern hybridization with a Tn5 fragment as a probe showed a single hybridized band in 7 mutants and these mutants appeared to have insertions at different sites of the chromosome. Tn5-inserted genes were isolated and the DNA sequence flanking Tn5 was determined. By comparing these with a sequence database, putative protein products encoded by bg genes were identified as follows: bg 3 as a LysR-type regulatory protein; bg 11 as a MalG protein in the maltose transport system; bg 14 as an oxidoreductase; and bg 17 as an ABC transporter. The sequences deduced from the three bg genes, bg 2, bg 7 and bg 16, showed no significant similarity to any protein with a known function, suggesting that these three bg genes may encode unidentified proteins responsible for the decolorization of brilliant green.
Collapse
Affiliation(s)
- Moon-Sun Jang
- Faculty of Biotechnology, College of Natural Resources and Life Science, Dong-A University, Busan 604-714, Korea
| | | | | | | | | |
Collapse
|
43
|
Abstract
The article deals with the novel physiological function of dissimilatory perchlorate reduction by strains JB101 and JB109 isolated from a laboratory-enriched mixed consortium originating from a sewage treatment facility. The biochemical and physiological data of the strains showed good correspondence with members of the family Enterobacteriaceae. The partial 16S rDNA sequence of the strains JB101 and JB109 had similarity of 99.8% to Citrobacter amalonaticus and 98% to Citrobacter farmeri, respectively. The results inferred the possibility of Citrobacter spp. to form an important group of dissimilatory perchlorate reducers among the gamma subclass of Proteobacteria, since the majority of the perchlorate reducers belong to two monophyletic groups, Dechloromonas and Dechlorosoma in beta subclass. The perchlorate-grown Citrobacter strains preferred perchlorate to nitrate as an electron acceptor unlike most of the reported dissimilatory perchlorate reducers.
Collapse
Affiliation(s)
- Nirmala Bardiya
- Department of Environmental Engineering, Inha University, Yonghyun-Dong, Nam-Gu, Inchon-402-751, South Korea
| | | |
Collapse
|
44
|
Abstract
We analyzed the ability of extraintestinal strains of Enterobacter spp. and Citrobacter spp. to employ different siderophore-mediated strategies of iron acquisition. All strains produced iron-chelating compounds. Cross-feeding assays indicated that most isolates of both Enterobacter spp. and Citrobacter spp. excreted catecholate siderophore enterobactin, less produced aerobactin, and single strains excreted hydroxamates different from aerobactin. Besides, we analyzed if the strains had the ability to produce the siderophore yersiniabactin coded by the Yersinia high-pathogenicity island (HPI). The presence of HPI genes was observed in single isolates of three species: E. cloaceae, E. aerogenes and C. koseri. A detailed polymerase chain reaction analysis revealed differences in the genetic organization of the HPIs; however, in a cross-feeding test we proved that yersiniabactin was produced and the island was functional.
Collapse
Affiliation(s)
- Joanna Mokracka
- Department of Microbiology, Institute of Experimental Biology, Adam Mickiewicz University, ul. Fredry 10, 61-701 Poznań, Poland.
| | | | | |
Collapse
|
45
|
Bugla G, Doroszkiewicz W, Gamian A, Korzeniowska-Kowal A. [Bactericidal activity of normal human serum to gram-negative rods with sialic acid containing lipopolysaccharide]. Med Dosw Mikrobiol 2004; 56:255-61. [PMID: 15773502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
The complement plays the most important role in eliminating bacterial invasion of the host, by facilitating phagocytosis of potential pathogens and by participating in the direct essential role in protecting gram-negative bacteria against bactericidal activity of serum. Sialic acids which are important constitutes of animal tissue glycoconjugates are also present in antigens of some bacterial strains. The susceptibility of gram-negative strains with sialic acid--containing lipopolysaccharides to bactericidal action sera was examined.
Collapse
Affiliation(s)
- Gabriela Bugla
- Zakład Mikrobiologii Instytutu Genetyki i Mikrobiologii Uniwersytetu Wrocławskiego
| | | | | | | |
Collapse
|
46
|
Hu HB, Liu YY, Fu JK, Xue R, Gu PY. [Recovery of platinum with immobilized Citrobacter freudii XP05 biomass]. Sheng Wu Gong Cheng Xue Bao 2003; 19:456-61. [PMID: 15969064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The objective of this work was to develop a valuable adsorbent for recovery of platinum by studying the properties of Pt4+ -adsorption with immobilized Citrobacter freudii XP05 biomass. Five methods for immobilization of Citrobacter freudii XP05 biomass were compared. The method with gelatin-alginate sodium as entrapment matrix was considered to be the optimal. Spherical and uniform beads were produced and the SEM micrograph indicated that the cell of strain XP08 were uniformly dispersed within the matrix. The adsorption of Pt4+ by immobilized XP05 biomass was affected with adsorptive time, pH value of the solution, immobilized biomass concentration, Pt4+ initial concentration The adsorption was a rapid process. The optimal pH value for Pt4+ adsorption was 1.5, and its adsorptive capacity increased linearly with increasing Pt4+ initial concentrations in the range of 50 - 250 mg/L. The experimental data could be fitted to Langmuir and Freundlich models of adsorption isotherm. The adsorptive capacity reached 35.2 mg/g under the conditions of 250 Pt4+ mg/L, 2.0 g/L immobilized biomass, pH 1.5 and 30 degrees C for 60 min. 98.7% of Pt4+ adsorbed on immobilized biomass could be desorbed with 0.5 mol HC1/L. The characteristics of dynamic adsorption and desorption of immobilized XP05 biomass in packed-bed reactor were investigated. The saturation uptake was 24.66 mg Pt4+ /g under the conditions of flow rate 1.2 mL/min, pH 1.5, 50 mg Pt4+/L and 1.85 g biomass(dry weight) . Adsorptive efficiency of Pt4 + by the immobilized XP05 biomass was above 78% for 4 cycles of adsorption and desorption. The recovery of platinum from waste platinum catalyst was studied. The adsorptive capacity was 20.94 mg Pt4+/g immobilized biomass under the conditions of 4.0 g/L immobilized XP05 biomass, 117.76 mg Pt4+/L and pH 1.5 for 60 min. The immobilized XP05 biomass is potentially applicable to the recovery of platinum from waste and wastewater containing platinum.
Collapse
Affiliation(s)
- Hong-Bo Hu
- School of Life Sciences, Xiamen University, Xiamen 361005, China
| | | | | | | | | |
Collapse
|
47
|
Deng W, Vallance BA, Li Y, Puente JL, Finlay BB. Citrobacter rodentium translocated intimin receptor (Tir) is an essential virulence factor needed for actin condensation, intestinal colonization and colonic hyperplasia in mice. Mol Microbiol 2003; 48:95-115. [PMID: 12657048 DOI: 10.1046/j.1365-2958.2003.03429.x] [Citation(s) in RCA: 151] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Citrobacter rodentium infection of mice serves as a relevant small animal model to study enterohaemorrhagic Escherichia coli (EHEC) and enteropathogenic E. coli (EPEC) infections in man. Enteropathogenic E. coli and EHEC translocate Tir into the host cytoplasmic membrane, where it serves as the receptor for the bacterial adhesin intimin and plays a central role in actin condensation beneath the adherent bacterium. In this report, we examined the function of C. rodentium Tir both in vitro and in vivo. Similar to EPEC, C. rodentium Tir is tyrosine phosphorylated and is essential for actin condensation. Citrobacter Tir and EPEC Tir are functionally interchangeable and both require tyrosine phosphorylation to mediate actin rearrangements. In contrast, Citrobacter Tir supports actin nucleation in EHEC independent of tyrosine phosphorylation, while EHEC Tir cannot replace Citrobacter Tir for this function. This indicates that C. rodentium and EPEC use an actin nucleating mechanism different from EHEC. We also found that Tir is expressed and translocated into mouse enterocytes in vivo by C. rodentium during infections. This represents the first direct demonstration of a type III effector translocated in vivo into a natural host by any pathogen. In addition, we showed that Tir, but not its tyrosine phosphorylation, is essential for C. rodentium to colonize the large bowel and induce attaching/effacing (A/E) lesions and colonic hyperplasia in mice, and that both EPEC Tir and EHEC Tir can substitute for Citrobacter Tir for these activities in vivo. These results thus demonstrate that Tir is an essential virulence factor in this infection model. The data also show that the function of Tir tyrosine phosphorylation and its subsequent actin nucleating activity are not essential for C. rodentium colonization of the mouse gut nor for inducing A/E lesions and colonic hyperplasia, thereby uncoupling colonization and disease from actin condensation for this A/E pathogen.
Collapse
Affiliation(s)
- Wanyin Deng
- Biotechnology Laboratory, University of British Columbia, Room 237 Wesbrook Building, 6174 University Boulevard, Vancouver, BC, V6T 1Z3, Canada
| | | | | | | | | |
Collapse
|
48
|
Manganello S, Tayara A, Perazzi B, Neira L, Famiglietti A, Pugliese L, Santini P, Vay C. [Characterization and distribution of Citrobacter species in a university hospital]. Enferm Infecc Microbiol Clin 2001; 19:11-4. [PMID: 11256240 DOI: 10.1016/s0213-005x(01)72541-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
OBJECTIVE [corrected] a) To identify Citrobacter strains following the conventional biochemical reaction of Brenner and col; b) to evaluate the sensitivity and specificity of the O'Hara's method compared with Brenner's method, and c) to determine the rate and distribution of the strains in the clinical isolates. MATERIAL AND METHODS One hundred and twenty two clinical isolates, characterized as Citrobacter spp. were collected between May of 1994 and August of 1997. Clinical isolates included inpatients and outpatients from Hospital de Clínicas. Strains were identified following the methods of Brenner and O'Hara. RESULTS Methods of Brenner identified 111 of 122 strains: C. freundii 59 of 111; C. koseri 18 of 111; C. werkmanii 15 of 111; C. braakii 9 of 111; C. youngae 6 of 111 and C. amalonaticus 4 of 111. O'Hara's methods identified 104 of 111 strains (94%). C. freundii was recovered most frequently from urine and feces (p Fisher < 0.026 and 0.039 respectively), while C. koseri was isolated from urine principally (p Fisher < 0.0372). CONCLUSIONS The genus Citrobacter is an important opportunistic pathogen that can be identified in clinical microbiology laboratories using O'Hara's method.
Collapse
Affiliation(s)
- S Manganello
- Cátedra de Análisis Clínicos I, Laboratorio de Bacteriología, Departamento de Bioquímica Clínica, Hospital de Clínicas, Universidad de Buenos Aires, Argentina
| | | | | | | | | | | | | | | |
Collapse
|
49
|
Abstract
A new aerobic denitrifier, Citrobacter diversus, was isolated from both nitrification and denitrification sludge. To monitor the variation in the concentration of nitrogen oxides, aerobic denitrification by C. diversus was carried out in a batch reactor. When the nitrate concentration was greater than 180 mg N l(-1), the nitrate reduction rate became stable. The effect of the C/N ratio on the denitrification activity was also investigated. The results showed that the optimum denitrification activity was obtained when the C/N ratio was 4-5. The range of the C/N ratio was higher than that for traditional anoxic denitrification. The effect of the dissolved oxygen concentration was further studied; and it was found that the range of dissolved oxygen concentrations, both for specific growth rates and for specific denitrification rates, was 2-6 mg(-1). From these results, it can be concluded that both the concentration of dissolved oxygen and the C/N ratio are key factors in the aerobic denitrification by C. diversus.
Collapse
Affiliation(s)
- H K Huang
- Graduate Institute of Environmental Engineering, National Taiwan University, Taipei
| | | |
Collapse
|
50
|
Macaskie LE, Bonthrone KM, Yong P, Goddard DT. Enzymically mediated bioprecipitation of uranium by a Citrobacter sp. : a concerted role for exocellular lipopolysaccharide and associated phosphatase in biomineral formation. Microbiology (Reading) 2000; 146 ( Pt 8):1855-1867. [PMID: 10931890 DOI: 10.1099/00221287-146-8-1855] [Citation(s) in RCA: 119] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A Citrobacter sp. accumulated uranyl ion (UO2(2+)) via precipitation with phosphate ligand liberated by phosphatase activity. The onset and rate of uranyl phosphate deposition were promoted by NH4(+), forming NH(4)UO(2)PO(4), which has a lower solubility product than NaUO(2)PO(4). This acceleration decoupled the rate-limiting chemical crystallization process from the biochemical phosphate ligand generation. This provided a novel approach to monitor the cell-surface-associated changes using atomic-force microscopy in conjunction with transmission electron microscopy and electron-probe X-ray microanalysis, to visualize deposition of uranyl phosphate at the cell surface. Analysis of extracted surface materials by (31)P NMR spectroscopy showed phosphorus resonances at chemical shifts of 0.3 and 2.0 p.p.m., consistent with monophosphate groups of the lipid A backbone of the lipopolysaccharide (LPS). Addition of fUO2(2+) to the extract gave a yellow precipitate which contained uranyl phosphate, while addition of Cd(2+) gave a chemical shift of both resonances to a single new resonance at 3 p.p.m. Acid-phosphatase-mediated crystal growth exocellularly was suggested by the presence of acid phosphatase, localized by immunogold labelling, on the outer membrane and on material exuded from the cells. Metal deposition is proposed to occur via an initial nucleation with phosphate groups localized within the LPS, shown by other workers to be produced exocellularly in association with phosphatase. The crystals are further consolidated with additional, enzymically generated phosphate in close juxtaposition, giving high loads of LPS-bound uranyl phosphate without loss of activity and distinguishing this from simple biosorption, or periplasmic or cellular metal accumulation mechanisms. Accumulation of 'tethered' metal phosphate within the LPS is suggested to prevent fouling of the cell surface by the accumulated precipitate and localization of phosphatase exocellularly is consistent with its possible functions in homeostatis and metal resistance.
Collapse
Affiliation(s)
- Lynne E Macaskie
- School of Biosciences, The University of Birmingham, Edgbaston, Birmingham B15 2TT, UK1
| | - Karen M Bonthrone
- School of Biosciences, The University of Birmingham, Edgbaston, Birmingham B15 2TT, UK1
| | - Ping Yong
- School of Biosciences, The University of Birmingham, Edgbaston, Birmingham B15 2TT, UK1
| | - David T Goddard
- Research and Technology, BNFL, Springfields Works, Preston PR4 OXJ, UK2
| |
Collapse
|