NGLC 2004-2010.National Geological Library of China All Rights Reserved. Add:29 Xueyuan Rd,Haidian District,Beijing,PRC. Mail Add: 8324 mailbox 100083 For exchange or info please contact us via email. |
NGLC 2004-2010.National Geological Library of China All Rights Reserved. Add:29 Xueyuan Rd,Haidian District,Beijing,PRC. Mail Add: 8324 mailbox 100083 For exchange or info please contact us via email. |
C, the synthesis of EPS in MRS-based broth ranged from 5.54 to 7.88 mgmL-1. EPS had an apparent molecular mass of ca. 104 Da. As shown by carbohydrate consumption,the synthesis of EPS was found from sucrose only. Two types of homopolysaccharides weresynthesized: glucans simultaneously with growth and fructans after 1 day of incubation. Two proteinbands of ca. 180-200 kDa were in situ detected on SDS-PAGE gels incubated with sucrose. PCRproducts of ca. 220 bp were found for L. plantarum PL9 (100% of identity to putative primingglycosyltransferase of L. plantarum WCFS1) and W. cibaria WC4 (80% of identity to putativeglycosyltransferase, epsD, of Bacillus cereus G9241) by using hybrid primers for the priming gtf genes.Degenerated primers DexreuR and DexreuV showed a unique PCR product, and the predicted aminoacid sequences were identical for W. cibaria WC4 and L. plantarum PL9. The sequence had similaritywith polysaccharide biosynthesis glycosyltransferases. W. cibaria WC4 or L. plantarum LP9synthesized ca. 2.5 g kg-1 EPS during sourdough fermentation with sucrose added. Compared tothe sourdough started with an EPS-negative strain, the sourdough started with W. cibaria WC4 or L.plantarum LP9 increased the viscosity, and the resulting bread had higher specific volume and lowerfirmness. The synthesis of EPS by selected sourdough lactic acid bacteria could be considered asa useful tool to replace the additives for improving the textural properties of baked goods.