| Project/Area Number |
14560284
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
生物資源科学
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| Research Institution | Hakodate National College of Technology |
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Principal Investigator |
UENO Takashi Hakodate National College of Technology, Associate professor, 助教授 (10310963)
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| Co-Investigator(Kenkyū-buntansha) |
NAKANISHI Kotoyoshi Tokyo University of Agriculture, Depart.of Brewing & Ferment, Professor, 教授 (70172351)
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| Project Period (FY) |
2002 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 2004: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2003: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2002: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | sucrose / lactic acid / syrup / a mixed sugar / Lactobacillus paracasei / Lactococcus lactis / catabolite repression |
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| Research Abstract |
1. Effect of carbon source on production of sucrose-hydrolyzable enzyme
Lactobacillus paracasei 1532 and Lactococcus lactis IFO12007 were cultured with 10 g l^<-1> sucrose, glucose, cellobiose or Methyl β-D-Glucopyranoside as sole carbon source, and enzyme activities were measured. Lb.paracasei 1532 showed high activity of sucrose-hydrolyzable enzyme when sucrose or cellobiose was used as sole carbon source. The strain also produced the enzyme when glucose was used. Therefore the enzyme of the strain is probably constitutive enzyme. Since the strain was capable to grow with Methyl β-D-Glucopyranoside, a part of the enzyme could be β-glucosidase. Lc.lactis IFO12007 grew very slowly when sucrose was used as sole carbon source, and the enzyme activity was very low.
2. Kinetic analysis in continuous production of lactic acid from canned pineapple syrup
Lb.paracasei 1532 was cultivated with 20 g l^<-1> sugar using canned pineapple syrup after precultivation with glucose. Then continuous cultivation was carried out feeding 100 g l^<-1> sugar of concentrated medium. All carbon sources including sucrose were metabolized until washout at 0.20 h^<-1> of dilution rate. As a result of kinetic analysis specific growth rate (μ_m) and Michaelis constant (K_s) were 0.24 h^<-1> and 2.4 g l^<-1>, respectively. Continuous cultivation by Lc.lactis IFO12007 was carried out in the same way after precultivation with sucrose. While glucose and fructose were completely consumed, sucrose could not be metabolized and accumulated in the culture broth. μ_m and _Ks were -0.04 h^<-1> and -53.06 g l^<-1>, respectively. Kinetic analysis also indicated that catabolite repression of sucrose by glucose and fructose occurred in Lc.lactis IFO12007 but no catabolite repression was observed in Lb.paracasei 1532.
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