Detection of D-Ornithine Extracellularly Produced by Corynebacterium Glutamicum ATCC 13032::Argf
Total Page:16
File Type:pdf, Size:1020Kb
Biosci. Biotechnol. Biochem., 74 (12), 2507–2510, 2010 Note Detection of D-Ornithine Extracellularly Produced by Corynebacterium glutamicum ATCC 13032::argF y Daisuke MATSUI and Tadao OIKAWA Department of Life Science and Biotechnology, Faculty of Chemistry, Materials and Bioengineering, Kansai University, 3-3-35 Yamate-Cho, Suita, Osaka 564-8680, Japan Received July 21, 2010; Accepted September 7, 2010; Online Publication, December 23, 2010 [doi:10.1271/bbb.100523] We found that Corynebacterium glutamicum ATCC the method of Hwang et al. using Escherichia coli 13032::argF extracellularly produced a large amount of JM110 instead of E. coli DH5 for non-methylation of a D-ornithine when cultivated in a CGXII medium vector transformed into C. glutamicum ATCC 13032.2) containing 1 mML-arginine. This is the first report that C. glutamicum ATCC 13032::argF was pre-cultivated C. glutamicum ATCC 13032 or its mutant produces a on a brain-heart infusion (BHI) agar medium (Difco, D-amino acid extracellularly. C. glutamicum ATCC BD, France), and then a single colony on the medium 13032::argF produced 13 mMD-ornithine in 45 h of was inoculated into 50 ml of a BHI medium in a 500-ml cultivation. Erlenmeyer flask with a baffle and cultivated at 30 C for 24 h with shaking (150 rpm) until the growth of the Key words: Corynebacterium glutamicum ATCC microorganism reached stationary phase. After centrifu- 13032; D-ornithine; ornithine carbamoyl- gation at 5;500 Â g for 15 min at 4 C, the collected cells transferase; ornithine racemase were washed with an ice-chilled CGXII medium plus 1mML-arginine,7) and inoculated into 50 ml of the same Corynebacterium glutamicum ATCC 13032 is a facul- medium at an A600 of 1.0. After 0, 3, 6, 9, 21, 24, 27, 30, tative anaerobe that is useful in the industrial production 45, 48, 54, 69, and 93 h, 0.5 ml of the culture broth was of various amino acids,1) including L-glutamic acid, taken from the flask and centrifuged at 16;100 Â g for L-lysine, L-threonine, and L-valine. In addition, C. 15 min at 4 C. The supernatant was diluted with a 0.1 M glutamicum ATCC 13032::argF, whose structural gene sodium acetate buffer (pH 7.2) 1 or 10 times, and encodes the ornithine carbamoyltransferase (argF, delivertized with o-phthalaldehyde after filtration with accession no. AAC24816) when the chromosome is a GL chromatodisc (0.2 mm, GL Science, Tokyo). The disrupted, produces L-ornithine as reported by Hwang sample was subjected to HPLC analysis. The course of et al.2) Hence various researchers have studied the D- and L-ornithine production by C. glutamicum ATCC enzymes in various L-amino acids biosynthetic pathways 13032 was also studied by the method described above. of C. glutamicum ATCC 13032 and their genes related to C. glutamicum ATCC 13032::argF was cultivated the regulation of various forms of L-amino acid produc- under the conditions described above to determine the tion.3–6) However, D-amino acids production of C. course of D- and L-ornithine production by C. glutami- glutamicum ATCC 13032 has not been reported so cum ATCC 13032::argF. After cultivation at 30 C far. During the course of biochemical studies of for 30 h, the cells were collected by centrifugation at C. glutamicum ATCC 13032::argF, we found that it 5;500 Â g for 15 min at 4 C. A portion of the collected extracellularly produces D-ornithine in addition to cells was suspended in a 10 mM Tris–HCl buffer L-ornithine. Here we describe the D-ornithine production (pH 8.0) plus 10% TritonX-100, and disrupted at 4 C of C. glutamicum ATCC 13032::argF as compared with twice by French pressure cell press FA-078 (SLM that of the wild-type strain. Aminco, Urbana, IL). After centrifugation at 5;500 Â g D-Ornithine was purchased from Watanabe Chemical for 15 min at 4 C, the supernatant solution obtained was Industries (Hiroshima, Japan). L-Ornithine was from used as a cell-free extract. Separately, a portion of the Wako Chemical (Osaka, Japan). All other chemicals collected cells was suspended in a 10 mM Tris–HCl used were from Kanto Kagaku (Tokyo), Kishida Chemi- buffer (pH 8.0) and disrupted by the French press. After cal (Osaka, Japan), Sigma-Aldrich (St. Louis, MO), or ultracentrifugation at 27;500 Â g for 30 min at 30 C Tokyo Kasei Kogyo (Tokyo), unless otherwise stated, (P70AT Rotor; Himac CP70MX Preparative Ultracen- and were of the best grade commercially available. trifuge, Hitachi Koki, Tokyo), the insoluble fraction Corynebacterium glutamicum ATCC 13032 was obtained was washed 4 times with deionised water and obtained as an NBRC 12168, from the type-culture used as a peptidoglycan fraction. A cell-free extract and collection of the Japanese National Institute of Tech- a peptidoglycan fraction of C. glutamicum ATCC 13032 nology and Evaluation (Ciba, Japan). C. glutamicum were prepared by the method described above using a ATCC 13032::argF, the ornithine carbamoyltransferase BHI and a CGXII medium without 1 mML-arginine. deletion mutant (accession no. AAC24816) of C. gluta- After 24 h of cultivation, the absorbance at 600 nm of the micum ATCC 13032, was prepared by a modification of culture broth of C. glutamicum ATCC 13032::argF and y To whom correspondence should be addressed. Tel: +81-6-6368-0812; Fax: +81-6-6388-8609; E-mail: [email protected] Abbreviations: AA, amino acid residue; PLP, pyridoxal 50-phosphate 2508 D. MATSUI and T. OIKAWA A 300,000 Time 21.307 Inten. 149,142 250,000 L-Orn D-Orn 200,000 uV 150,000 Standard 100,000 Sample A 50,000 Sample B 0 14.0 15.0 16.0 17.0 18.0 19.0 20.0 21.0 22.0 Retention time (min) B (x10,000) Max Intensity : 41.988 Time 34.272 Scan 2.914 Inten. -8.701 7.5 D-Orn (m/z: 216) 5.0 L-Orn (m/z: 216) MIC 2.5 Standard Sample A Sample B 0.0 31.031.5 32.0 32.5 33.0 33.5 34.0 34.5 Retention time (min) Fig. 1. Detection and Identification of D-Ornithine in the Culture Broth of Corynebacterium glutamicum ATCC 13032::argF. A, HPLC analysis. Sample A, D- and L-ornithine extracellularly produced by C. glutamicum ATCC 13032::argF after cultivation for 21 h. Sample B, D- and L-ornithine extracellularly produced by C. glutamicum ATCC 13032 after cultivation for 21 h. Standards, 10 mMD- and L-ornithine in deionized water. B, GC-MS analysis. Sample A, D- and L-ornithine extracellularly produced by C. glutamicum ATCC 13032::argF after cultivation for 21 h. Sample B, D- and L-ornithine extracellularly produced by C. glutamicum ATCC 13032 after cultivation for 21 h. Standards, 20 mMD- and L-ornithine in deionized water. of C. glutamicum ATCC 13032 reached 54:20 Æ 0:5 and solvent B for 5.5 min. The sample for HPLC analysis was 54:17 Æ 0:2 respectively. delivertized with o-phthalaldehyde and N-tert-butyloxy- A peptidoglycan fraction was hydrolyzed with hydro- carbonyl-L-cysteine (BocC) by the method of Buck gen chloride with a Pico-Tag Work Station (Waters, et al.12) A sample (10 ml) was mixed with methanol Tokyo) at 110 C for 20 h following the protocol of the (0.1 ml) containing 7.5 mg of o-phthalaldehyde and manufacturer. The hydrolyzed samples were dried under 7.5 mg of N-tert-butyloxycarbonyl-L-cysteine (BocC), reduced pressure and resuspened in a mixture (95%, and then 5.0 ml of a 0.4 M sodium borate buffer (pH 10.4) v/v) containing 5 mM disodium phosphate in deionized containing 15 ml of Brij 30 was added to the mixture. water and adjusted to pH 7.4 with 1 N NaOH and The growth of the microorganism in the culture broth acetonitrile (5%, v/v). An aliquot of this solution was was measured photometrically at 600 nm with a UV-VIS subjected to GC-MS analysis. photometer V-550 (Jasco, Tokyo). GC-MS analysis was carried out with a gas chroma- We found that C. glutamicum ATCC 13032::argF tography GC-2010 system equipped with a Model extracellularly produced large amount of an unknown QP2010 mass spectrometer (GC-MS, Shimadzu, Kyoto, amino acid when cultivated in a CGXII medium Japan). A fused silica capillary column, ChirasilÒ-L-Val containing 1 mML-arginine. The unknown amino acid (Varian, Darmstadt, Germany) was used to separate and produced was identified by GC-MS analysis and HPLC quantify D- and L-amino acids by a method previously analysis. It was eluted at a retention time of 15.85 min reported.8–10) on HPLC analysis, and this retention time coincided HPLC analysis was carried out with a high-performance well with that of an authentic D-ornithine (Fig. 1A). liquid chromatography LC-10AD system (Shimadzu). GC-MS analysis indicated that the unknown amino acid A Hypersil ODS column (particle size, 5 mm, 4 Â 250 was eluted at a retention time of 32.25 min, and it mm; Agilent, Santa Clara, CA) was used to separate showed an m=z value of 216 (Fig. 1B). This m=z value D- and L-ornithine method of Erbe et al.11) The column agreed well with the theoretical m=z value of D-ornithine temperature was kept at 40 C, and the adsorbed sample (216). Accordingly, the unknown amino acid produced was eluted with a linear gradient of a 0.1 M acetate buffer, by C.