Partial characterization of anEscherichia coll strain harboring a xylanase encoding plasmid

Summary The plasmid pRH271, harboring a xylanase gene cioned fromBaciliussubtilis, has been transferred into a mutant ofE.coli SK2284 which allowed the release of part of the xylanase in the culture supernatant. Kinetic parameters of this recombinantE.coll strain were determined in microscale batch culture with and without the selective pressure of antibiotics. No significant difference in µ_max was observed for the nontransformedE.coli strain when compared to the recombinant strain. However, K₅ values for glucose were two times higher in the case of the recombinant strain. Preliminary study of xylanase production in a large batch farmenter was also described.