title: Cloning and expression of delta-1-pyrroline-5-carboxylate dehydrogenase in Escherichia coli DH5α improves phosphate solubilization.
abstract: A primary cDNA library of Penicillium oxalicum I1 was constructed using the switching mechanism at the 5' end of the RNA transcript (SMART) technique. A total of 106 clones showed halos in tricalcium phosphate (TCP) medium, and clone I-40 showed clear halos. The full-length cDNA of clone I-40 was 1355 bp with a complete open reading frame (ORF) of 1032 bp, encoding a protein of 343 amino acids. Multiple alignment analysis revealed a high degree of homology between the ORF of clone I-40 and delta-1-pyrroline-5-carboxylate dehydrogenase (P5CDH) of other fungi. The ORF expression vector was constructed and transformed into Escherichia coli DH5α. The transformant (ORF-1) with the P5CDH gene secreted organic acid in medium with TCP as the sole source of phosphate. Acetic acid and α-ketoglutarate were secreted in 4 and 24 h, respectively. ORF-1 decreased the pH of the medium from 6.62 to 3.45 and released soluble phosphate at 0.172 mg·mL(-1) in 28 h. Expression of the P. oxalicum I1 p5cdh gene in E. coli could enhance organic acid secretion and phosphate-solubilizing ability.
authors.affiliation: a Key Laboratory of Microbial Resources, Ministry of Agriculture / Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, People's Republic of China.
authors.forename: Mingbo
authors.initials: M
authors.lastname: Gong
authors.forename: Chaoxi
authors.initials: C
authors.lastname: Tang
authors.forename: Changxiong
authors.initials: C
authors.lastname: Zhu
mesh_terms: D050842:1-Pyrroline-5-Carboxylate Dehydrogenase / Q000235:genetics* / Q000378:metabolism*; D019342:Acetic Acid / Q000378:metabolism; D002130:Calcium Phosphates / Q000378:metabolism*; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D015723:Gene Library; D005822:Genetic Vectors; D007656:Ketoglutaric Acids / Q000378:metabolism; D010407:Penicillium / Q000201:enzymology* / Q000235:genetics; D011994:Recombinant Proteins / Q000378:metabolism; D012995:Solubility; D014169:Transformation, Bacterial
chemical_list: D002130:Calcium Phosphates; D007656:Ketoglutaric Acids; D011994:Recombinant Proteins; D050842:1-Pyrroline-5-Carboxylate Dehydrogenase; C018392:tricalcium phosphate; D019342:Acetic Acid
keywords: Penicillium oxalicum; SMART; acide organique; delta-1-pyrroline-5-carboxylate dehydrogenase; delta-1-pyrroline-5-carboxylate déshydrogénase; organic acid; phosphate solubilizing; solubilisation du phosphate; « SMART »