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Reyes-Pérez A, Vargas MDC, Hernández M, Aguirre-von-Wobeser E, Pérez-Rueda E, Encarnacion S. Transcriptomic analysis of the process of biofilm formation in Rhizobium etli CFN42. Arch Microbiol 2016; 198:847-60. [PMID: 27226009 DOI: 10.1007/s00203-016-1241-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 03/17/2016] [Accepted: 05/06/2016] [Indexed: 12/19/2022]
Abstract
Organisms belonging to the genus Rhizobium colonize leguminous plant roots and establish a mutually beneficial symbiosis. Biofilms are structured ecosystems in which microbes are embedded in a matrix of extracellular polymeric substances, and their development is a multistep process. The biofilm formation processes of R. etli CFN42 were analyzed at an early (24-h incubation) and mature stage (72 h), comparing cells in the biofilm with cells remaining in the planktonic stage. A genome-wide microarray analysis identified 498 differentially regulated genes, implying that expression of ~8.3 % of the total R. etli gene content was altered during biofilm formation. In biofilms-attached cells, genes encoding proteins with diverse functions were overexpressed including genes involved in membrane synthesis, transport and chemotaxis, repression of flagellin synthesis, as well as surface components (particularly exopolysaccharides and lipopolysaccharides), in combination with the presence of activators or stimulators of N-acyl-homoserine lactone synthesis This suggests that R. etli is able to sense surrounding environmental conditions and accordingly regulate the transition from planktonic and biofilm growth. In contrast, planktonic cells differentially expressed genes associated with transport, motility (flagellar and twitching) and inhibition of exopolysaccharide synthesis. To our knowledge, this is the first report of nodulation and nitrogen assimilation-related genes being involved in biofilm formation in R. etli. These results contribute to the understanding of the physiological changes involved in biofilm formation by bacteria.
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Affiliation(s)
- Agustín Reyes-Pérez
- Programa de Genómica Funcional de Procariotes, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Apartado Postal 565-A, Cuernavaca, Morelos, Mexico.,Facultad de Ciencias, Posgrado en Ciencias Biológicas, Universidad Nacional Autónoma de México, Apartado Postal 70-153, C.P. 0415, Cuernavaca, D.F., Mexico.,Centro de Investigación en Dinámica Celular, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, Cuernavaca, Morelos, 62209, Mexico
| | - María Del Carmen Vargas
- Programa de Genómica Funcional de Procariotes, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Apartado Postal 565-A, Cuernavaca, Morelos, Mexico
| | - Magdalena Hernández
- Programa de Genómica Funcional de Procariotes, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Apartado Postal 565-A, Cuernavaca, Morelos, Mexico
| | - Eneas Aguirre-von-Wobeser
- Red de Estudios Moleculares Avanzados, Instituto de Ecología, A. C. Coatepec 351, El Haya, Xalapa, Veracruz, Mexico
| | - Ernesto Pérez-Rueda
- Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, UNAM, Av. Universidad s/n, Col. Chamilpa, Cuernavaca, Morelos, Mexico
| | - Sergio Encarnacion
- Programa de Genómica Funcional de Procariotes, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Apartado Postal 565-A, Cuernavaca, Morelos, Mexico.
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Navarro-Alarcon M, Reyes-Pérez A, Lopez-Garcia H, Palomares-Bayo M, Olalla-Herrera M, Lopez-Martinez MC. Longitudinal study of serum zinc and copper levels in hemodialysis patients and their relation to biochemical markers. Biol Trace Elem Res 2006; 113:209-22. [PMID: 17194922 DOI: 10.1385/bter:113:3:209] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2005] [Revised: 08/25/2005] [Accepted: 09/20/2005] [Indexed: 11/11/2022]
Abstract
A 6-mo longitudinal study of 48 hemodialysis patients (HPs) with chronic renal failure was performed. Three blood samplings were done. Samples of whole blood from each patient were collected during hemodialysis sessions after passing through the artificial kidney. Zinc and copper levels were measured by atomic absorption spectrometry. Additionally, 36 biochemical indexes were evaluated during the study. Fifty-two healthy matched controls were also considered. Mean serum zinc and copper concentrations in HPs were significantly decreased (Zn) and increased (Cu), when compared with healthy controls (p < 0.01). Zinc concentrations found in the first and second blood samplings from patients were significantly lower than those measured for the third sampling (p < 0.01). The etiology of chronic renal failure influenced the statistically serum Zn levels of patients (p < 0.05). Serum copper levels of HPs were significantly diminished by the existence of secondary associated diseases (p < 0.01). Uric acid and parathyroid hormone, and total-cholesterol and glutamic-pyruvic-transaminase levels were significantly (p < 0.05) and linearly related with serum zinc and copper concentrations, respectively. From all of indexes, creatinine, direct bilirubin, magnesium, calcium, parathyroid hormone, transferrin, and albumin were statistically modified along the longitudinal study (p < 0.05). Transferrin serum levels were significantly diminished in the third blood sampling, indicating the tendency toward anemia in the patients. This result is reinforced by low levels of biochemical and hematological indexes related with iron body staus.
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Affiliation(s)
- M Navarro-Alarcon
- Department of Nutrition and Food Science, School of Pharmacy, University of Granada, Granada, Spain
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Del Carmen Vargas M, Encarnación S, Dávalos A, Reyes-Pérez A, Mora Y, García-de Los Santos A, Brom S, Mora J. Only one catalase, katG, is detectable in Rhizobium etli, and is encoded along with the regulator OxyR on a plasmid replicon. Microbiology (Reading) 2003; 149:1165-1176. [PMID: 12724378 DOI: 10.1099/mic.0.25909-0] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [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
The plasmid-borne Rhizobium etli katG gene encodes a dual-function catalase-peroxidase (KatG) (EC 1.11.1.7) that is inducible and heat-labile. In contrast to other rhizobia, katG was shown to be solely responsible for catalase and peroxidase activity in R. etli. An R. etli mutant that did not express catalase activity exhibited increased sensitivity to hydrogen peroxide (H(2)O(2)). Pre-exposure to a sublethal concentration of H(2)O(2) allowed R. etli to adapt and survive subsequent exposure to higher concentrations of H(2)O(2). Based on a multiple sequence alignment with other catalase-peroxidases, it was found that the catalytic domains of the R. etli KatG protein had three large insertions, two of which were typical of KatG proteins. Like the katG gene of Escherichia coli, the R. etli katG gene was induced by H(2)O(2) and was important in sustaining the exponential growth rate. In R. etli, KatG catalase-peroxidase activity is induced eightfold in minimal medium during stationary phase. It was shown that KatG catalase-peroxidase is not essential for nodulation and nitrogen fixation in symbiosis with Phaseolus vulgaris, although bacteroid proteome analysis indicated an alternative compensatory mechanism for the oxidative protection of R. etli in symbiosis. Next to, and divergently transcribed from the catalase promoter, an ORF encoding the regulator OxyR was found; this is the first plasmid-encoded oxyR gene described so far. Additionally, the katG promoter region contained sequence motifs characteristic of OxyR binding sites, suggesting a possible regulatory mechanism for katG expression.
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Affiliation(s)
- María Del Carmen Vargas
- Programa de Ingeniería Metabólica, Centro de Investigación sobre Fijación de Nitrógeno, Universidad Nacional Autónoma de México, Apdo. Postal 565-A, Cuernavaca, Morelos, CP62210, Mexico
| | - Sergio Encarnación
- Programa de Ingeniería Metabólica, Centro de Investigación sobre Fijación de Nitrógeno, Universidad Nacional Autónoma de México, Apdo. Postal 565-A, Cuernavaca, Morelos, CP62210, Mexico
| | - Araceli Dávalos
- Programa de Ingeniería Metabólica, Centro de Investigación sobre Fijación de Nitrógeno, Universidad Nacional Autónoma de México, Apdo. Postal 565-A, Cuernavaca, Morelos, CP62210, Mexico
| | - Agustín Reyes-Pérez
- Programa de Ingeniería Metabólica, Centro de Investigación sobre Fijación de Nitrógeno, Universidad Nacional Autónoma de México, Apdo. Postal 565-A, Cuernavaca, Morelos, CP62210, Mexico
| | - Yolanda Mora
- Programa de Ingeniería Metabólica, Centro de Investigación sobre Fijación de Nitrógeno, Universidad Nacional Autónoma de México, Apdo. Postal 565-A, Cuernavaca, Morelos, CP62210, Mexico
| | - Alejandro García-de Los Santos
- Programa de Genética Molecular de Plásmidos Bacterianos, Centro de Investigación sobre Fijación de Nitrógeno, Universidad Nacional Autónoma de México, Apdo. Postal 565-A, Cuernavaca, Morelos, CP62210, Mexico
| | - Susana Brom
- Programa de Genética Molecular de Plásmidos Bacterianos, Centro de Investigación sobre Fijación de Nitrógeno, Universidad Nacional Autónoma de México, Apdo. Postal 565-A, Cuernavaca, Morelos, CP62210, Mexico
| | - Jaime Mora
- Programa de Ingeniería Metabólica, Centro de Investigación sobre Fijación de Nitrógeno, Universidad Nacional Autónoma de México, Apdo. Postal 565-A, Cuernavaca, Morelos, CP62210, Mexico
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