Methods for preparing L-tagatose

Abstract

The invention relates to methods for preparing L-tagatose, which belongs to the field of biotechnology. A method for preparing the L-tagatose comprises the following steps: preparing a culture medium; culturing acid-producing bacteria to obtain primary seed liquid; obtaining secondary seed liquid; inoculating secondary seed liquid to a fermentation culture medium to obtain fermentation liquor; obtaining primary yeast seed liquid and secondary yeast seed liquid and centrifuging the primary yeast seed liquid and the secondary yeast seed liquid to obtain yeast cells; culturing the yeast cells to obtain clear fermentation liquor; concentrating, decolorizing and filtering the clear fermentation liquor to obtain solution; and passing the solution through an ion exchange resin, performing crystallization, washing crystals and drying the crystals to obtain the L-tagatose. A method for preparing the L-tagatose by converting D-dulcitol by using resting cells comprises the following steps: preparing a culture medium; culturing bacteria; suspending somatic cells of the bacteria to obtain solution; inoculating candida ssp. CGMCC No.3268 to obtain fermentation liquor; and subjecting the fermentation liquor to decolorizing and desalting processing to obtain aqueous solution, concentrating the aqueous, performing crystallization, washing crystals and drying the crystals to obtain the L-tagatose. The methods of the invention can be used for preparing pharmaceutical L-tagatose.

Description

Technical field [0001] The invention relates to a preparation method in the field of biotechnology, in particular to a method for preparing L-tagatose. Background technique [0002] Tagatose is a rare six-carbon sugar, divided into D-tagatose and L-tagatose. Although they exist in nature, the amount is very scarce, and the amount of L-tagatose is very rare. D-tagatose, as a low-calorie and safe sugar, was approved by the US FDA as early as 2001, and there are unlimited restrictions. It has also entered the phase III clinical trial as a clinical drug for preventing diabetes. [0003] After searching the literature of the prior art, it is found that the main methods for synthesizing D-tagatose are: using metal hydroxide or sodium aluminate as a catalyst to isomerize D-galactose to produce D-tagatose (US Patent US5002612, publication date: March 26, 1991; Chinese patent CN200610123316.5, publication date: 2007.6.27; World of Chemistry, 2009, Issue 3, pages 187-188); L-arabinose isome...

AI Technical Summary

Problems solved by technology

The raw material L-biloxose used in this method itself is also a very rare and rare sugar, which is expensive, and it has to go through the process of reduction and oxidation in turn, and there is also the problem of regeneration of coenzyme factors.

Make it unrealistic to use this method to prepare L-tagatose

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