title: Identification of the Anabaena sp. strain PCC7120 cyanophycin synthetase as suitable enzyme for production of cyanophycin in gram-negative bacteria like Pseudomonas putida and Ralstonia eutropha.
abstract: The cyanophycin synthetase gene cphA1 encoding the major cyanophycin synthetase (CphA) of Anabaena sp. strain PCC7120 was expressed in Escherichia coli conferring so far the highest specific CphA activity to E. coli (6.7 nmol arginine per min and mg protein). CphA1 and cphA genes of Synechocystis sp. strains PCC6803 and PCC6308 and Synechococcus strain MA19 were also expressed in wild types and polyhydroxyalkanoate-negative (PHA) mutants of Pseudomonas putida and Ralstonia eutropha. Recombinant strains of these bacteria expressing cphA1 accumulated generally more cyanophycin (23.0 and 20.0% of cellular dry matter, CDM, respectively) than recombinants expressing any other cphA (6.8, 9.0, or 15.8% of CDM for P. putida strains and 7.3, 12.6, or 14.1% of CDM for R. eutropha). Furthermore, PHA-negative mutants of P. putida (9.7, 10.0, 17.5, or 24.0% of CDM) and R. eutropha (8.9, 13.8, 16.0, or 22.0% of CDM) accumulated generally more cyanophycin than the corresponding PHA-positive parent strains (6.8, 9.0, 15.8, and 23.0% of CDM for P. putida strains and 7.3, 12.6, 14.1, or 20.0% of CDM for R. eutropha strains). Recombinant strains of Gram-positive bacteria (Bacillus megaterium, Corynebacterium glutamicum) were not suitable for cyanophycin production due to accumulation of less cyanophycin and retarded release of cyanophycin. PHA-negative mutants of P. putida and R. eutropha expressing cphA1 of Anabaena sp. strain PCC7120 are therefore preferred candidates for industrial production of cyanophycin.
authors.affiliation: Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität Münster, Corrensstrabetae 3, D-48149 Münster, Germany.
authors.forename: Ingo
authors.initials: I
authors.lastname: Voss
authors.forename: Simone Cardoso
authors.initials: SC
authors.lastname: Diniz
authors.forename: Elsayed
authors.initials: E
authors.lastname: Aboulmagd
authors.forename: Alexander
authors.initials: A
authors.lastname: Steinbüchel
mesh_terms: D017033:Anabaena / Q000201:enzymology* / Q000235:genetics; D001410:Bacillus megaterium / Q000737:chemistry / Q000235:genetics; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics; D003001:Cloning, Molecular; D020118:Cupriavidus necator / Q000737:chemistry* / Q000235:genetics; D004247:DNA / Q000235:genetics / Q000302:isolation & purification; D004926:Escherichia coli / Q000737:chemistry / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics; D006090:Gram-Negative Bacteria / Q000737:chemistry / Q000235:genetics; D006851:Hydrochloric Acid / Q000737:chemistry; D010453:Peptide Synthases / Q000737:chemistry* / Q000235:genetics; D010940:Plant Proteins / Q000096:biosynthesis*; D016958:Pseudomonas putida / Q000737:chemistry* / Q000235:genetics; D011994:Recombinant Proteins / Q000235:genetics; D013045:Species Specificity
chemical_list: D001426:Bacterial Proteins; D010940:Plant Proteins; D011994:Recombinant Proteins; C024250:cyanophycin; D004247:DNA; D010453:Peptide Synthases; C113257:cyanophycin synthase, bacteria; D006851:Hydrochloric Acid