title: Response of Fe-S cluster assembly machinery of Escherichia coli to mechanical stress in a model of amino-acid crystal fermentation.
abstract: During amino-acid crystal fermentation, mechanical stress on bacterial cells caused by crystal collision often impacts negatively on bacterial growth and amino-acid production. When Escherichia coli cells were cultivated under mechanical stress of polyvinyl chloride particles as a model of the crystal fermentation, activities of iron-sulfur (Fe-S) cluster-containing enzymes were apparently decreased. Based on an assumption that function of Fe-S cluster assembly machinery would be elevated to recover the enzyme activities in such stressed cells, we analyzed levels of various components of Fe-S cluster assembly machinery by western blotting. It was found that the expression of HscA, a chaperon component of the machinery, was up-regulated and that shorter forms of HscA with the N-terminal region truncated were accumulated, suggesting an important role of HscA against the mechanical stress. An overexpression of HscA gene in E. coli cells gave a positive effect on rescue of the stress-induced decrease of the activity of Fe-S cluster-containing enzyme. These results may provide a new strategy to alleviate the mechanical stress during the amino-acid crystal fermentation.
authors: Research Institute for Bioscience Products & Fine Chemicals, Ajinomoto Co., Inc., 1-1 Suzuki-cho, Kawasaki-ku, Kawasaki 210-8681, Japan. Electronic address: satoshi_okutani@ajinomoto.com.
authors: Satoshi
authors: S
authors: Okutani
authors: Research Institute for Bioscience Products & Fine Chemicals, Ajinomoto Co., Inc., 1-1 Suzuki-cho, Kawasaki-ku, Kawasaki 210-8681, Japan. Electronic address: takayoshi_Iwai@ajinomoto.com.
authors: Takayoshi
authors: T
authors: Iwai
authors: Research Institute for Bioscience Products & Fine Chemicals, Ajinomoto Co., Inc., 1-1 Suzuki-cho, Kawasaki-ku, Kawasaki 210-8681, Japan. Electronic address: shintaro_iwatani@ajinomoto.com.
authors: Shintaro
authors: S
authors: Iwatani
authors: Research Institute for Bioscience Products & Fine Chemicals, Ajinomoto Co., Inc., 1-1 Suzuki-cho, Kawasaki-ku, Kawasaki 210-8681, Japan. Electronic address: Matsuno_Kiyoshi@eli.ajinomoto.com.
authors: Kiyoshi
authors: K
authors: Matsuno
authors: Division of Life Science, Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama 338-8570, Japan. Electronic address: ytaka@molbiol.saitama-u.ac.jp.
authors: Yasuhiro
authors: Y
authors: Takahashi
authors: Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 560-0871, Japan. Electronic address: enzyme@protein.osaka-u.ac.jp.
authors: Toshiharu
authors: T
authors: Hase
mesh_terms: D000596:Amino Acids / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism*; D061249:Batch Cell Culture Techniques; D015153:Blotting, Western; D003460:Crystallization; D004926:Escherichia coli / Q000201:enzymology* / Q000254:growth & development / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D005285:Fermentation; D015964:Gene Expression Regulation, Bacterial; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D007506:Iron-Sulfur Proteins / Q000378:metabolism*; D011143:Polyvinyl Chloride; D013314:Stress, Mechanical; D015854:Up-Regulation
chemical_list: D000596:Amino Acids; D029968:Escherichia coli Proteins; D018840:HSP70 Heat-Shock Proteins; D007506:Iron-Sulfur Proteins; C085650:hscA protein, E coli; D011143:Polyvinyl Chloride
keywords: Amino-acid crystal fermentation; Escherichia coli; Fed-batch cultivation; HscA; ISC machinery; Iron–sulfur cluster assembly; Mechanical stress