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US 10,308,908 B2Granted
Method of producing ethanol using continuous culture and continuous culture apparatus
AssigneeToyota Jidosha Kabushiki Kaisha
InventorsHibiki Matsushita, Emiko Tominaga
Life of this patent
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Abstract
A method of producing ethanol includes: measuring a xylose concentration in a culture fluid that contains microorganisms having xylose utilizing ability, the culture fluid including a culture medium that contains saccharides derived from lignocellulose; and performing an addition control in which an additional culture medium is added to the culture fluid to conduct a continuous culture of the microorganisms, the additional culture medium containing saccharides derived from lignocellulose.
Claims9
A continuous culture apparatus comprising:
- a culture tank in which microorganisms having xylose utilizing ability are continuously cultured in a culture medium containing saccharides derived from lignocellulose;
- a culture medium supply section that is programmed to perform a supply of an additional culture medium to the culture tank, the additional culture medium containing saccharides derived from lignocellulose, and wherein the additional culture medium does not contain the microorganisms;
- a xylose concentration measuring section that is programmed to measure a xylose concentration in a culture fluid in the culture tank;
- and
- a controller that is programmed to control the supply based on the measured xylose concentration, such that the xylose concentration is adjusted to be a preset threshold or lower, wherein said preset threshold is ⅓ or lower of the xylose concentration in the culture fluid before the start of culturing, wherein the controller is programmed to control a supply rate of the additional culture medium to the culture fluid such that the number of cells of microorganisms used for ethanol production produced per unit time and unit liquid volume in the continuous culture is more than the number of cells of microorganisms used for ethanol production produced per unit time and unit liquid volume in a batch culture in which the culture medium is used,
- and wherein the supply rate is higher than F which is obtained from the following equation
- F=V×(xmax−x0)/xs×T/(tbatch×(T−ti))
- where F represents a supply rate of the additional culture medium,
- V represents a liquid volume of the culture fluid,
- xmax represents a maximum concentration of microorganisms used for ethanol production in the batch culture in which the culture medium is used,
- x0 represents a concentration of microorganisms used for ethanol predilection at a start of the batch culture in which the culture medium is used,
- xs represents a concentration of microorganisms used for ethanol production in a steady state of the continuous culture in which the culture medium is used,
- T represents a time for which the steady state is maintained in the culture fluid,
- tbatch represents a total time required for the batch culture in which the culture medium is used, and
- ti represents a total time required until the steady state is established in the continuous culture in which the culture medium is used.
12 more elements
A continuous culture apparatus comprising:
- a culture tank in which microorganisms having xylose utilizing ability are continuously cultured in a culture medium containing saccharides derived from lignocellulose;
- a culture medium supply section that is programmed to perform a supply of an additional culture medium to the culture tank, the additional culture medium containing saccharides derived from lignocellulose, and wherein the additional culture medium does not contain the microorganisms;
- a xylose concentration measuring section that is programmed to measure a xylose concentration in a culture fluid in the culture tank;
- and
- a controller that is programmed to control the supply based on the measured xylose concentration, such that the xylose concentration is adjusted to be a preset threshold or lower, wherein said preset threshold is 10 g/L or lower.
2 more elements
A continuous culture apparatus comprising:
- a culture tank in which microorganisms having xylose utilizing ability are continuously cultured in a culture medium containing saccharides derived from lignocellulose;
- a culture medium supply section that is programmed to perform a supply of an additional culture medium to the culture tank, the additional culture medium containing saccharides derived from lignocellulose, and wherein the additional culture medium does not contain the microorganisms;
- a xylose concentration measuring section that is programmed to measure a xylose concentration in a culture fluid in the culture tank;
- and
- a controller that is programmed to control the supply based on the measured xylose concentration, wherein the controller is programmed to control a supply rate of the additional culture medium to the culture fluid such that the number of cells of microorganisms used for ethanol production produced per unit time and unit liquid volume in the continuous culture is more than the number of cells of microorganisms used for ethanol production produced per unit time and unit liquid volume in a batch culture in which the culture medium is used,
- and wherein the supply rate is higher than F which is obtained from the following equation
- F=V×(xmax−x0)/xs×T/(tbatch×(T−ti))
- where F represents a supply rate of the additional culture medium,
- V represents a liquid volume of the culture fluid,
- xmax represents a maximum concentration of microorganisms used for ethanol production in the batch culture in which the culture medium is used,
- x0 represents a concentration of microorganisms used for ethanol production at a start of the batch culture in which the culture medium is used,
- xs represents a concentration of microorganisms used for ethanol production in a steady state of the continuous culture in which the culture medium is used,
- T represents a time for which the steady state is maintained in the culture fluid,
- tbatch represents a total time required for the batch culture in which the culture medium is used, and
- ti represents a total time required until the steady state is established in the continuous culture in which the culture medium is used.
12 more elements
Dependencies are inferred from the claim text.