Method for preparing D-psicose using microorganism of genus <i>Kaistia</i>

Abstract

Provided are a composition for preparing D-psicose comprising a microorganism of the genus Kaistia, and a method for preparing D-psicose using the same.

Claims

1. A method for preparing D-psicose, comprising: contacting a microorganism of the genus Kaistia with D-fructose, wherein D-fructose is converted to D-psicose.

2. The method of claim 1, wherein the microorganism of the genus Kaistia is at least one microorganism of the genus Kaistia selected from the group consisting of Kaistia granuli, Kaistia defluvii, Kaistia geumhonensis, Kaistia adipata, Kaistia dalseonensis, Kaistia hirudinis, Kaistia soli and Kaistia terrae.

3. The method of claim 2, wherein the Kaistia granuli is Kaistia granuli LIS1 strain deposited with Accession number KCCM11916P.

4. The method of claim 2, wherein the Kaistia defluvii is Kaistia defluvii LIS2 strain deposited with Accession number KCCM12020P.

5. The method of claim 1, wherein the contacting is performed at pH of 5.0 to 9.0, at a temperature of 40° C. to 90° C., or for 0.5 to 48 hours.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is HPLC analytical data showing that it is possible to prepare psicose from D-fructose using Kaistia granuli LIS1, according to an exemplary embodiment of the present invention.

(2) FIG. 2 is HPLC analytical data showing that it is possible to prepare psicose from D-fructose using Kaistia defluvii LIS2, according to an exemplary embodiment of the present invention.

(3) FIG. 3 is HPLC analytical data showing that it is possible to prepare psicose from D-fructose using Kaistia granuli KCTC12575, according to an exemplary embodiment of the present invention.

(4) FIG. 4 is HPLC analytical data showing that it is possible to prepare psicose from D-fructose using Kaistia defluvili KCTC23766, according to an exemplary embodiment of the present invention.

(5) FIG. 5 is HPLC analytical data showing that it is possible to prepare psicose from D-fructose using Kaistia geumhonensis KCTC12849, according to an exemplary embodiment of the present invention.

(6) FIG. 6 is HPLC analytical data showing that it is possible to prepare psicose from D-fructose using Kaistia adipata KCTC12095, according to an exemplary embodiment of the present invention.

(7) FIG. 7 is HPLC analytical data showing that it is possible to prepare psicose from D-fructose using Kaistia dalseonensis KCTC12850, according to an exemplary embodiment of the present invention.

(8) FIG. 8 is HPLC analytical data showing that it is possible to prepare psicose from D-fructose using Kaistia hirudinis DSM25966, according to an exemplary embodiment of the present invention.

(9) FIG. 9 is HPLC analytical data showing that it is possible to prepare psicose from D-fructose using Kaistia soli DSM19436, according to an exemplary embodiment of the present invention.

(10) FIG. 10 is HPLC analytical data showing that it is possible to prepare psicose from D-fructose using Kaistia terrae DSM21341, according to an exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS

(11) Hereinafter, the present invention will be described in more detail by the following Examples. However, the present invention is not limited to Examples below, and it should be understood that various modifications and changes may be made by those skilled in the art within the scope and spirit of the present invention.

(12) Throughout the specification of the present invention, unless otherwise noted, “%” used to denote a concentration of a specific material refers to a solid/solid (weight/weight) %, a solid/liquid (weight/volume) %, and a liquid/liquid (volume/volume) %.

EXAMPLES

Example 1. Isolation of Soil-Born Microorganism that Convert D-Fructose to Psicose

(13) To isolate the microorganism that convert D-fructose to psicose, a minimal medium (KH.sub.2PO.sub.4 of 2.4 g/L, K.sub.2HPO.sub.4 of 5.6 g/L, (NH.sub.4).sub.2SO.sub.4 of 2.6 g/L, 3 mM MnSO.sub.4, 7H.sub.2O of 0.1 g/L, yeast extract of 1 g/L) to which 1% (w/v) psicose was added was used. 1 g of rhizosphere soil was suspended in 10 mL of 0.85% (w/v) NaCl, and 100 μl of the suspension was plated on an agar medium and cultured at 30° C. Colonies having different shapes and sizes were selected among the colonies formed in the agar medium, and each colony was inoculated into the minimal medium (KH.sub.2PO.sub.4 of 2.4 g/L, K.sub.2HPO.sub.4 of 5.6 g/L, (NH.sub.4).sub.2SO.sub.4 of 2.6 g/L, 3 mM MnSO.sub.4, 7H.sub.2O of 0.1 g/L, yeast extract of 1 g/L) and subjected to shaking culture at 30° C. for 24 hours, followed by centrifugation to recover only the cells. The recovered cells were washed with 0.85% (w/v) NaCl, and then, allowed to float by adding 50 mM Tris-Cl buffer (pH 8.0) in which 50% (w/w) D-fructose and 3 mM MnSO.sub.4 were added in 20% (w/w) of cell concentration, followed by reaction with the cells at 55° C. for 2 hours. The reaction product was centrifuged to remove the cells the reaction solution, and preparation of the psicose was confirmed by HPLC of the supernatant. The HPLC analysis was performed using HPLC (Agilent, USA) Refractive Index Detector (Agilent 1260 RID) equipped with Aminex HPX-87C column (BIO-RAD), wherein a mobile phase solvent was water, a temperature was 80° C., and a flow rate was 0.6 ml/min. Two kinds of strains (LIS1 and LIS2) that prepared psicose from the D-fructose the most were selected by HPLC analysis (FIGS. 1 and 2).

(14) Base sequences (5′ to 3′) of the 16s ribosomal DNA of the selected strains LIS1 and LIS2 are as shown in SEQ ID NOs: 1 and 2, respectively. As a result of the sequence homology analysis, SEQ ID NO: 1 showed about 99% homology with the 16s ribosomal DNA sequence (SEQ ID NO: 3) of Kaistia granuli Ko04, and SEQ ID NO: 2 showed about 99% homology with the 16s ribosomal DNA sequence (SEQ ID NO: 4) of Kaistia defluvii B6-12. Accordingly, the strain LIS1 was identified as of Kaistia granuli, and the strain LIS2 was identified as Kaistia defluvii, respectively, and named Kaistia granuli LIS1 and Kaistia defluvii LIS2, respectively. The two strains were deposited in the Korean Culture Center of Microorganisms (KCCM) which is an international depository under the Budapest Treaty, wherein the Kaistia granuli LIS1 was deposited on Oct. 20, 2016, and granted accession number KCCM11916P, and the Kaistia defluvii LIS2 strain was deposited on Apr. 24, 2017, and granted accession number KCCM12020P.

Example 2. Confirmation of Preparation of Psicose by Microorganism of the Genus Kaistia

(15) Whether the psicose could be prepared by the Kaistia granuli LIS1, the Kaistia defluvii LIS2, other strains of the same species, and a different kind of strain of the genus Kaistia was confirmed.

(16) Specifically, eight additional microorganisms (same species: K. granuli KCTC12575 and K. defluvii KCTC23766; different species: Kaistia geumhonensis KCTC12849; K. dalseonensis KCTC12850, K. hirudinis DSM25966, K. soli DSM19436 and K. terrae DSM21341) were purchased from the Korean Collection for Type Cultures (KTCT) and Deutsche Sammlung von Mikroorganismen and Zellkulturen inoculated into normal medium (glucose 1 g/L, peptone 15 g/L, NaCl 6 g/L, yeast extract 3 g/L) and subjected to shaking culture at 30° C. for 24 hours, followed by centrifugation to recover only the cells. The recovered cells ere washed with 0.85% (w/v) NaCl and then reacted with 50% (w/w) D-fructose under the same condition as in Example 1 in which the cell concentration was 20% (w/w). After completion of the reaction, the reaction supernatant was analyzed by HPLC to confirm a preparation amount of the psicose. The HPLC analysis was performed in the sale manner as in Example 1. Psicose conversion rate was calculated by the ratio of weight amount of produced psicose after reaction to weight amount of d-fructose before reaction.

(17) As a result, it was confirmed that all of the eight strains of the genus Kaistia prepared the psicose from the D-fructose, and this shows that all kinds microorganism of the genus Kaistia can produce psicose from D-fructose at a high temperature (table 1, FIGS. 3 to 10).

(18) TABLE-US-00001 TABLE 1 Strain Conversion rate(%) K. granuli LIS1 28 K. granuli KCTC12575 25 K. defluvii LIS2 28 K. defluvii KCTC23766 23 K. geumhonensis KCTC12849 11 K. aditapa KCTC12095 4 K. dalseonensis KCTC12850 1 K. hirudinis DSM25966 10 K. soli DSM19436 4 K. terrae DSM21341 23

(19) From the above description, it will be understood by those skilled in the art that the present invention can be made in other specific forms without modifying a technical idea or essential characteristics thereof. In this regard, it should be understood that the embodiments described above are illustrative in all aspects and not restrictive. The scope of the present invention should be interpreted to cover all modifications or variations derived from the meaning and scope of the appended claims and their equivalents rather than the detailed description.