1995 Fiscal Year Final Research Report Summary
Development of the fermentaion system for production of biodegradable plastics from tropial resources.
| Project/Area Number |
06044173
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| Research Category |
Grant-in-Aid for international Scientific Research
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| Allocation Type | Single-year Grants |
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| Section | Joint Research |
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
ISHIZAKI Ayaaki Dept.Food Sci.Technol., Fac.Agr., Kyushu Univ., Professor, 農学部, 教授 (20183163)
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| Co-Investigator(Kenkyū-buntansha) |
FURUKAWA Kensuke Dept.Agr.Chem., Fac.Agr., Kyushu Univ., 農学部, 教授 (90221556)
FUJIO Yusaku Dept.Food Sci.Technol., Fac.Agr., Kyushu Univ., 農学部, 教授 (90038224)
STANBURY Peter f Microbiology and Genetics, Univ.Hertfordshire, 教授
TANAKA Kenji Dept.Food Sci.Technol., Fac.Agr., Kyushu Univ., 農学部, 助手 (20236582)
SONOMOTO Kenji Dept.Food Sci.Technol., Fac.Agr., Kyushu Univ., 農学部, 助教授 (10154717)
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| Project Period (FY) |
1994 – 1995
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| Keywords | xylose / PHB / L-Lactate / agricultural waste / two-stage fermentation / biodegradable plastic / Lactococcus lactis 10-1 / Alcaligenes eutrophus |
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| Research Abstract |
Bioprocess development nad biochemical approaches for fermentative production of L-lactate from xylose have been carried out. Hence biodegradable plastics, PHA such as polylactate or polyhydroxybutylate can be produced from agricultural waste. Japanese team has studied continuous substrate feed for lactic acid fermentation employing Lactococcus lactis 10-1 using glucose medium. Satisfactory results were obtained by the pH-dependent feed (two pH sets points DDC control system) with turbidity control to maintain high cell density and low lactate level in the culture broth. This system can be attained a high dilution rate (D) by resulting lower product inhibition by lower inhibitor level. Now, we are being engaged the operation of the fermentation with this control system using xylose as a sole carbon source. Kinetic parameters for L-lactate fermentation from xylose have been studied and determined. L-lactate fermentation from xylose is inherently accompanying acetic acid however acetic acid concentration accumulated in the culture broth in the range of fermentable initial xylose concentration did not observe solid influence of the product inhibition. Thus the kinetic parameters can be determined by the function using one inhibitor constant for L-lactate.
English team has carried out the experiment of glucose-xylose mixed substrate feed continuous culture using the same strain 10-1. They have found that the lower glucose level in the spent medium stimulates higher xylose consumption rate and larger substrate feeding rate. They are also interested in xylose isomerase harbored in the gene of 10-1.
Both Japanese and English have agreed to translate the second edition of "Principles of Fermentation Technology" into Japanese as soon as possible.
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