Preparation and preservation of freeze-dried cells of acetic acid bacteria with aldehyde oxidase activity.
Freeze-dried cells of acetic acid bacteria were prepared to use as an additive for manufacturing and processing foods. When the freeze-dried cells were stored for 1 week at 5 degrees C, however, more than 50% of the original activity of aldehyde oxidase (AOX) was lost. It was found that this decrease in AOX was caused by damage to both the membrane-bound aldehyde dehydrogenase and terminal oxidase activities involved in the aldehyde oxidase electron transport system of acetic acid bacteria. The addition of 30% sucrose to the cell suspension prepared in a McIlvaine buffer (pH 6) before lyophilization was found to be effective for preventing the decrease of AOX activity. Cells freeze-dried in this way lost no AOX activity at all during first 3 weeks of storage at 5 degrees C and, even after 9 weeks, 80% of the original activity remained.
Nomura
Y
Y
Somatech Center, House Foods Corporation, Osaka, Japan.
Yamamoto
M
M
Matsushita
K
K
Kumagai
H
H
D000091:Acetobacter / Q000201:enzymology*; D042931:Aldehyde Oxidase; D000445:Aldehyde Oxidoreductases / Q000378:metabolism*; D000596:Amino Acids / Q000494:pharmacology; D002241:Carbohydrates / Q000494:pharmacology; D004187:Disaccharides / Q000494:pharmacology; D004795:Enzyme Stability; D005612:Freeze Drying; D006863:Hydrogen-Ion Concentration; D011309:Preservation, Biological / Q000379:methods*
D000596:Amino Acids; D002241:Carbohydrates; D004187:Disaccharides; D000445:Aldehyde Oxidoreductases; D042931:Aldehyde Oxidase