title: Heat-enhanced production of chitosanase from Streptomyces griseus in the presence of liposome.
abstract: The effects of heat stress and liposome treatment on the growth of Streptomyces griseus cells and chitosanase production were investigated on the basis of using the designed strategy of a stress-mediated bioprocess. The effective conditions for increasing the interaction between chitosanase and the 1-palmitoyl-2-oleoyl-3-phosphocholine (POPC) liposome under heat stress condition were determined on the basis of the results of circular dichroism (CD) and dielectric dispersion analysis (DDA). Under these effective conditions, S. griseus cells were cultivated for the effective production of chitosanase. The results obtained from both CD spectra and DDA showed that heat stress enhances the interaction of the POPC liposomes and chitosanase. The strongest interaction between them could be obtained in the specific temperature range of 40-45 degrees C. The enhancement of the target chitosanase production was conducted under heat stress at 41 degrees C in the presence and absence of the POPC liposomes. The growth rates of S. griseus cells in the cases of heat (41 degrees C) and heat (41 degrees C)/POPC treatments were respectively 1.2 and 1.4 times higher than that obtained under the control condition. In the heat (41 degrees C) and heat (41 degrees C)/POPC treatments, chitosanase activity increased to 1.8 and 2 times, respectively, higher than that obtained under the control condition. Heat stress and the addition of the POPC liposomes could therefore be utilized to induce the potential functions of bacterial cells for the enhancement of the final target production.
authors.affiliation: Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Japan.
authors.forename: Kien Xuan
authors.initials: KX
authors.lastname: Ngo
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Umakoshi
authors.forename: Toshinori
authors.initials: T
authors.lastname: Shimanouchi
authors.forename: Ho Sup
authors.initials: HS
authors.lastname: Jung
authors.forename: Seiichi
authors.initials: S
authors.lastname: Morita
authors.forename: Ryoichi
authors.initials: R
authors.lastname: Kuboi
mesh_terms: D003470:Culture Media / Q000737:chemistry / Q000494:pharmacology; D006026:Glycoside Hydrolases / Q000096:biosynthesis*; D006358:Hot Temperature; D008081:Liposomes / Q000737:chemistry / Q000494:pharmacology*; D010713:Phosphatidylcholines / Q000737:chemistry / Q000494:pharmacology*; D013305:Streptomyces griseus / Q000201:enzymology* / Q000254:growth & development
chemical_list: D003470:Culture Media; D008081:Liposomes; D010713:Phosphatidylcholines; C034973:1-oleoyl-2-palmitoylphosphatidylcholine; D006026:Glycoside Hydrolases; C019868:chitosanase