Abstract
Azotobacter vinelandii produces two polymers of industrial importance, i.e. alginate and poly-β-hydroxybutyrate (PHB). Alginate synthesis constitutes a waste of substrate when seeking to optimize PHB production and, conversely, synthesis of PHB is undesirable when optimizing alginate production. In this study we evaluated the effect of a mutation in algA, the gene encoding the enzyme that catalyzes the first step of the alginate biosynthetic pathway in the production of PHB. We also evaluated production of alginate in strain AT6 carrying a phbB mutation that impairs PHB synthesis. The algA mutation prevented alginate production and increased PHB accumulation up to 5-fold, determined in milligrams per milligram of protein. Similarly, the phbB mutation increased alginate production up to 4-fold.
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References
Alexeyev FA, Shokolenko IN, Croughan TP (1995) Improved antibiotic-resistance gene cassettes and omega elements for Escherichia coli vector construction and in vivo deletion/insertion mutagenesis. Gene 160:63–67
Anderson AJ, Dawes EA (1990) Occurrence, metabolism, metabolic role, and industrial uses of bacterial polyhydroxyalkanoates. Microbiol Rev 54:450–472
Beale JM, Foster JL (1996) Carbohydrate fluxes into alginate biosynthesis in Azotobacter vinelandii NCIB 8789: NMR investigations of the triose pools. Biochemistry 35:4492–4501
Brivonese AC, Sutherland IW (1989) Polymer production by a mucoid strain of Azotobacter vinelandii in batch culture. Appl Microbiol Biotechnol 30:97–102
Byrom D (1987) Polymer synthesis by microorganisms: technology and economics. Trends Biotechnol 5:246–250
Ertesvag H, Hoidal HK, Hals IK, Rian A, Doseth B, Valla S (1995) A family of modular type mannuronan C-5-epimerase genes controls alginate structure in Azotobacter vinelandii. Mol Microbiol 16:719–731
Jain S, Ohman DE (1998) Deletion of algK in mucoid Pseudomonas aeruginosa blocks alginate polymer formation and results in uronic acid secretion. J Bacteriol 180:634–641
Kennedy C, Gamal R, Humphrey R, Ramos J, Brigle K, Dean D (1986) The nifH, nifM and nifN genes of Azotobacter vinelandii: Characterization by Tn5 mutagenesis and isolation from pLARF1 gene banks. Mol Gen Genet 205:318–325
Knutson CA, Jeanes A (1968) A new modification of the carbazole analysis: application to heteropolysaccharides. Anal Biochem 24:470–481
Law JH, Slepecky RA (1961) Assay of polyhydroxybutiric acid. J Bacteriol 82:33–36
Lee YL (1996) Bacterial polyhydroxyalkanoates. Biotechnol Bioeng 49:1–14
Lowry D, Rosenbrough N, Farr A, Randall R (1951) Protein measurement with the Folin phenol reagent. J Biol Chem 193:265–275
Martínez P, Guzmán J, Espín G (1997) A mutation impairing alginate production increased accumulation of poly-β-hydroxybutyrate in Azotobacter vinelandii. Biotechnol Lett 19:909–912
Núñez C, León R, Guzmán J, Espín G, Soberón-Chávez G (2000) Role of Azotobacter vinelandii mucA and mucC gene products in alginate production. J Bacteriol 182:6550–6556
Page WJ, Knosp O (1989) Hyperproduction of poly-β-hydroxybutyrate during exponential growth in Azotobacter vinelandii UWD. Appl Environ Microbiol 55:1334–1339
Parente E, Crudele MA, Ricciardi A, Mancini M, Clementi F (2000) Effect of ammonium sulfate concentration and agitation speed on the kinetics of alginate production by Azotobacter vinelandii DSM576 in batch fermentation. J Ind Microbiol Biotechnol 25:242–248
Peralta-Gil M, Segura D, Guzmán J, Servín-Gonzalez L, Espín G (2002) Expression of the Azotobacter vinelandii poly-β-hydroxybutyrate biosynthetic phbBAC operon is driven by two overlapping promoters and is dependent on the transcriptional activator PhbR. J Bacteriol 184:5672–5677
Pindar DF, Bucke C (1975) The biosynthesis of alginic acid by Azotobacter vinelandii. Biochem J 152:617–622
Rehm HA, Valla S (1997) Bacterial alginates: biosynthesis and applications. Appl Microbiol Biotechnol 178:5884–5889
Rehm HA, Ertesvag H, Valla S (1996) A new Azotobacter vinelandii mannuronan C-5-epimerase (algG) is part of the alg gene cluster physically in a manner similar to that in Pseudomonas aeruginosa. J Bacteriol 178:5884–5889
Segura D, Espín G (1998) Mutational inactivation of a gene homologous to Escherichia coli ptsP affects poly-β-hydroxybutyrate accumulation and nitrogen fixation in Azotobacter vinelandii. J Bacteriol 180:4790–4798
Segura D, Cruz T, Espín G (2000) β-ketothiolase genes in Azotobacter vinelandii. Gene 260:113–120
Segura D, Cruz T, Espín G (2003) Encystment and alkylresorcinol production by Azotobacter vinelandii strains impaired in poly-β-hydroxybutyrate synthesis. Arch Microbiol 179:437–443
Vázquez A, Moreno S, Guzmán J, Alvarado A, Espín G (1999) Transcriptional organization of the Azotobacter vinelandii algGXLVIFA genes: characterization of algF mutants. Gene 232:217–222
Acknowledgements
This work was supported by grants 36276-N from CONACyT and IN-209399 from DGAPA/UNAM. We thank R. Stock for reviewing the manuscript and S. Moreno and R. Nájera for technical support.
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Segura, D., Guzmán, J. & Espín, G. Azotobacter vinelandii mutants that overproduce poly-β-hydroxybutyrate or alginate. Appl Microbiol Biotechnol 63, 159–163 (2003). https://doi.org/10.1007/s00253-003-1397-1
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DOI: https://doi.org/10.1007/s00253-003-1397-1