Increased production of bacteriocin ST4SA by Enterococcus mundtii ST4SA in modified corn steep liquor
Date
2007
Authors
Coetzee J.C.J.
Todorov S.D.
Gorgens J.F.
Dicks L.M.T.
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Enterococcus mundtii ST4SA produces a broad-spectrum bacteriocin (bacST4SA), active against Gram-positive and Gram-negative bacteria. Growth in corn steep liquor (CSL) with a sugar content of 5.0 and 10.0 g/l yielded bacST4SA levels of 12800 AU/ml. A four-fold increase in bacST4SA production (51200 AU/ml) was recorded in CSL with a sugar content of 7.5 g/l supplemented with 6.5 g/l yeast extract (CSL-YE). Poor growth and low levels of bacST4SA production were observed when cells were grown in CSL-YE controlled at pH 5.5. Fermentation at pH 7.5 yielded 25600 AU/ml after 6 h, but the activity levels decreased to approximately 1000 AU/ml during the next 6 h. Adjustment of the culture pH from 6.5 to 5.5 after 6 h of fermentation extended bacST4SA activity (51200 AU/ml) over 8 h. Activity then decreased to 25600 AU/ml and was maintained this level for 10 h. Optimal levels of bacST4SA production (102400 AU/ml) were obtained after 6 h of fermentation in CSL-YE supplemented with 7.5 g/l glucose at the start of the fer-mentation. This level of production was maintained by changing the culture pH from 6.5 after 6 h of fermentation to pH 5.5. This study proved that bacST4SA could be produced at high levels in an inexpensive industrial medium by E. mundtii ST4SA.
Description
Keywords
Enterococcus, Enterococcus mundtii, Negibacteria, Posibacteria, Zea mays
Citation
Annals of Microbiology
57
4
57
4