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標題: Isolation of a Xanthomonas campestris strain with elevated beta-galactosidase activity for direct use of lactose in xanthan gum production
作者: Yang, T.C.
Wu, G.H.
Tseng, Y.H.
關鍵字: construction;whey
Project: Letters in Applied Microbiology
期刊/報告no:: Letters in Applied Microbiology, Volume 35, Issue 5, Page(s) 375-379.
Aims: To isolate a Xanthomonas campestris strain that can use lactose directly for xanthan gum production. Methods and Results: The presence of indigenous beta-galactosidase gene in the wild-type Xc17 was detected by PCR and Southern hybridization. Treatment of Xc17 with nitrous acid resulted in the isolation of Xc17L with a 3.5-fold elevation of beta-galactosidase activity capable of growing in lactose-based medium. Xc17L is stable for at least 100 generations in terms of beta-galactosidase expression. The amounts of xanthan produced by Xc17L in lactose-based medium are comparable to those in glucose-based medium. Conclusions: Xc17L is potentially useful for xanthan production from whey, a waste containing lactose. Significance and Impact of the Study: A lactose-utilizing strain of X. campestris strain can be constructed without incorporation of any exotic DNA or antibiotic resistance gene and therefore concern of a gene-modified organism and fear of a spread of an antibiotic-resistant gene are avoided.
ISSN: 0266-8254
DOI: 10.1046/j.1472-765X.2002.01202.x
Appears in Collections:期刊論文

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