Bacterial cellulose production by Acetobacter xylinum in a 50-L internal-loop airlift reactor

Abstract

Bacterial cellulose (BC) production was realized in a batch cultivation of Acetobacter xylinum subsp. sucrofermentans BPR2001 in a 50-L internal-loop airlift reactor. When the bacterium was cultivated with air supply, 3.8 g/L of BC was produced after 67 hours. When oxygen-enriched gas was supplied, the concentration of BC was doubled and the production rate of BC was 0.116 g/L. h, which was two times higher than that of air-supplied culture and comparable to that in a mechanically agitated stirred-tank fermentor. Bacterial cellulose produced by the airlift reactor formed a unique ellipse pellet (BC pellet), different from the fibrous form which was produced in an agitated stirred-tank fermentor. The BC-pellet suspension was demonstrated to have a higher volumetric oxygen transfer coefficient than the fibrous BC suspension in a 50-L internal-loop airlift reactor. The mixing time of BC-pellet suspension in the airlift reactor was also shorter than that in water.

Formation of Highly Twisted Ribbons in a Carboxymethylcellulase Gene-Disrupted Strain of a Cellulose-Producing Bacterium

“…Cellulose analyses. The amount of celluloses in the culture was measured according to the method described by Chao et al (26).…”

Effects of Acetan on Production of Bacterial Cellulose by Acetobacter xylinum

“…A. xylinum was grown on FPY consisting of 2z fructose, 1z Polypepton (Nihon Seiyaku Co., Ltd., Tokyo, Japan), 0.5z yeast extract (Oriental Yeast Co., Ltd., Tokyo), 0.25z K2HPO4 (pH 5.0), or else on a medium of corn steep liquor (Nihon Starch Industry, Kagoshima, Japan) and fructose (CSL-Fru), the composition of which was described elsewhere, 18) at 309 C. E. coli DH5a was grown on Luria-Bertani medium consisting of 1z Tryptone peptone (Becton Dickinson and Company, Sparks, Maryland, USA), 0.5z yeast extract (Becton Dickinson) and 1z NaCl at 379 C. Ampicillin (Sigma Chemical Co., St. Louis, Missouri, USA) was added at 50 ppm for E. coli and at 100 ppm for A. xylinum, and kanamycin (Wako Pure Chemical Industries, Ltd., Osaka, Japan) was added at 100 ppm for E. coli when necessary.…”

“…The supernatant obtained by centrifugation of the homogenized culture broth was then treated with two volumes of ethanol, and the precipitate was rinsed with the potassium acetate buŠer and assayed for acetan by the phenol-sulfate method. 18,22) Residual fructose was assayed by HPLC as previously described.…”

Sustainable optically transparent composites based on epoxidized soy-bean oil (ESO) matrix and high contents of bacterial cellulose (BC)

“…BC nanofibers are several nanometers wide with very high aspect ratio. They present excellent mechanical properties including tensile strength and modulus, high water-holding capacity, high moldability, crystallinity, and biocompatibility, that make them excellent reinforcement for polymeric matrices (Borzani and Desouza 1995;Chao et al 2000;Putra et al 2008;Yan et al 2008).…”