Method for cultivating apparatus for the production of bacterial cellulose in an aerated and agitated culture

• US 6,013,490 A
• Filed: 03/25/1997
• Issued: 01/11/2000
• Est. Priority Date: 03/25/1997
• Status: Expired due to Fees

• Current Assignee: Bio-Polymer Research Co., Ltd.
• Original Assignee: Bio-Polymer Research Co., Ltd.
• Inventors: Nagata, Yasuhisa, Kouda, Tohru, Yoshinaga, Fumihiro, Yano, Hisato
• Primary Examiner(s): PRATS, FRANCISCO CHANDLER
• Application Number:
  US08/824,096
• Time in Patent Office: 1,022 Days
• Field of Search: 435/101, 536/56, 536/126
• US Class Current: 435/101
• CPC Class Codes: C12M 27/06 with horizontal or inclined stirrer shaft or axis
• CPC Class Codes: C12P 19/12 Disaccharides

Abstract

A method for the production of a bacterial cellulose by cultivating a cellulose-producing bacteria for at least a certain period of time under such an apparatus condition that an oxygen-transfer coefficient (K_L a) is about 25 to about 50/hr, said K_L a is determined by using a simulated suspension containing 2% by weight of BC and having a plastic viscosity of 15 to 20 poise.

Claims

1. A method for the production of a bacterial cellulose (BC) comprising cultivating a cellulose-producing bacterium under such apparatus conditions that the oxygen-transfer coefficient (K_L a) of the equation below is about 25 to about 50/hr, said K_L a is determined by employing a simulated suspension containing 2% by weight of bacterial cellulose (BC) and having a plastic viscosity of 15-20 poise:

##EQU3## wherein C_L is the dissolved oxygen concentration in the culture medium (mmol/l), t is time (hr), dC_L /dt is the change in dissolved oxygen concentration over a certain period of time, K_L is the oxygen-transfer coefficient (cm/hr) at a liquid boundary membrane, a is the area of gas-liquid interface per unit volume (cm² /cm³), and C* is the dissolved oxygen concentration (mmol/l) in equilibrium with the partial pressure of oxygen in air bubbles.

2. The method of claim 1, comprising conducting the cultivation in an apparatus provided with an impeller on the horizontal axis in a fermenter.

3. The method of claim 1, wherein the cellulose producing microorganism being cultured is a strain of Acetobacter, Agrobacterium, Rhizobium, Sarcina, Pseudomonus, Achromobacter, Alcaligenes, Aerobacter, Azotobacter or Zooglea.

4. The method of claim 3, wherein said strain of Acetobacter is Acetobacter xylinum subsp. sucrofermentans, Acetobacter xylinum ATCC 23768, Acetobacter xylinum ATCC 23769, Acetobacter pasteurianus ATCC 10245, Acetobacter xylinum ATCC 14851, Acetobacter xylinum ATCC 11142 or Acetobacter xylinum ATCC 10821.

5. The method of claim 4, wherein said cultivation occurs at a pH of 3 to 7 at a temperature in the range of 10 to 40°

C. at an oxygen supply of 1 to 100%.

6. The method of claim 5, wherein said pH is about 5.

7. The method of claim 1, which further comprises conducting the cultivation in an apparatus provided with an impeller generating both axial and radial flows, and a seprate turbine impeller within the same fermenter.

8. The method of claim 7, wherein each of the impellers are rotated at a rate of 400-1200 rpm.