PROCESS FOR PRODUCTION OF CRYSTALLINE XYLITOL USING PICHIA CARIBBICA AND ITS APPLICATION FOR QUORUM SENSING INHIBITION

摘要

The inventors disclose a novel room temperature process for the synthesis of crystalline xylitol with high yield and purity from D-xylose using Pichia caribbica yeasts that acts as a quorum sensing antagonist that prevents bio film formation by gram-negative bacteria. Further a mild and safe procedure for xylitol extraction is disclosed.

主权项

1. A room temperature fermentation process for the synthesis of crystalline xylitol from D-xylose using yeast strain Pichia Caribbica BY2 having MTCC No. 5703 comprising the steps of:
a. inoculating 108 cells per ml of MXYP (malt extract xylose yeast extract and peptone medium) with yeast strain Pichia caribbica BY2 and incubating at temperature in the range of 25 to 28° C. in a rotary shaker at 170 to 180 rpm for period in the range of 20 to 24 hours to obtain inoculated MXYP broth; b. adding the inoculated MXYP broth as obtained in step (a) into 90 ml MXYP broth and further incubating for period in the range of 40 to 48 hours to get sufficient cell biomass; c. harvesting cells from MYXP broth by centrifugation at 4500 to 5000 rpm for period in the range of 15 to 20 minutes at temperature in the range of 4 to 10° C.; d. re-dispersing the cells from step, (c) in the ratio ranging between 3 to 4 g % of 9.5 to 10% D-Xylose solution and incubating further for period in the range of 70 to 72 hr; e. separating cells by centrifugation at 4500 to 5000 rpm for period in the range of 15 to 20 mins at temperature in the range of 4° C. to 10° C.; f. concentrating the yellow coloured supernatant obtained in step (e) by rotary vacuum evaporation in a 85° C. water bath to obtain the bright yellow viscous fluid; g. further concentrating the bright yellow viscous fluid obtained as obtained in step (f) by centrivac concentrator system; h. crystallizing the concentrated bright yellow viscous fluid as obtained in step (g) by refrigerating at temperature in the range of (−)15° C. to (−)20° C. for period in the range of 40 to 48 hours, to obtain semi-crystalline yellow material; i. decolourizing the semi-crystalline yellow coloured material as obtained in step (h) using absolute ethanol to obtain crystalline xylitol with 0.8 to 0.9 gm/gm yield and 98 to 99% purity.