1. High level production of a cellulase-free xylanase in glucose-limited fed batch cultures of a thermophilic Bacillus strain
- Author
-
J. P. Touzel, Ph Debeire, Eric Samain, Laboratoire de Génie des Procédés et Technologie Alimentaires (LGPTA), Institut National de la Recherche Agronomique (INRA), Centre de Recherches sur les Macromolécules Végétales (CERMAV), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF), ProdInra, Migration, and Carret, Michèle
- Subjects
[SPI.GPROC] Engineering Sciences [physics]/Chemical and Process Engineering ,[SDV]Life Sciences [q-bio] ,Oligosaccharides ,Bioengineering ,Bacillus ,Cellulase ,Applied Microbiology and Biotechnology ,03 medical and health sciences ,Hydrolysis ,Enzyme Stability ,[SDV.IDA]Life Sciences [q-bio]/Food engineering ,[SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering ,Food science ,Amino Acids ,ComputingMilieux_MISCELLANEOUS ,030304 developmental biology ,0303 health sciences ,Strain (chemistry) ,biology ,030306 microbiology ,Chemistry ,Thermophile ,Temperature ,General Medicine ,[SDV.IDA] Life Sciences [q-bio]/Food engineering ,BLANCHISSEMENT ,Xylan ,Xylan Endo-1,3-beta-Xylosidase ,[SDV] Life Sciences [q-bio] ,Kinetics ,Glucose ,Xylosidases ,Kraft process ,Biochemistry ,Mutation ,biology.protein ,Xylanase ,Xylooligosaccharide ,Biotechnology - Abstract
Bacillus sp. strain XE and its mutant derivative strain D3 produce a thermostable xylanase which is suitable for enzymatic bleaching of kraft pulp. Xylanase synthesis was shown to be induced by the soluble products of xylan hydrolysis (xylooligosaccharide) and equally, catabolically-repressed when these oligosaccharides accumulate in the medium. An optimal balance between these two antagonistic effects was obtained in a carbon-limited, fed-batch culture with continuous xylooligosaccharide feeding. To reduce substrate cost, the xylooligosaccharide could be 90% substituted by glucose without reduction of the xylanase production rate. Xylanase production ceased when the activity reached approximately 380 U ml-1 due to an amino acid shortage. A continuous supply of exogenous amino acids allowed the production to continue to more than 1000 U ml-1.
- Published
- 1997