Bacillus subtilis highly producing tetramethylpyrazine and method thereof for fermentation producing tetramethylpyrazine

Abstract

The invention relates to a bacillus subtilis highly producing tetramethylpyrazine and a method thereof for fermentation producing tetramethylpyrazine, and belongs to the technical field of bio-engineering. The invention discloses a Bacillus subtilis XZ1124 which can highly produce tetramethylpyrazine, and is preserved in CCTCC, and the preservation number is CCTCC NO: M 208157. The strain is made of Maotai-flavor liquor and high temperature Daqu; the strain is identified as Bacillus subtilis based on colony, cell form, physiological and biochemical characteristics and 16S rRNA gene sequence comparative result thereof. The strain can utilizes glucose, sucrose, molasses and soybean cake powder as substrate, and increases the output of tetramethylpyrazine through accumulating a great deal of endogenous precursors, so as to solve the problems of low product density, exogenous adding precursor requirement, and low precursor utilization rate in tetramethylpyrazine production through microbe fermentation. When sucrose and soybean cake powder are used as substrate, 4.08 g/L of tetramethylpyrazine can obtained through shaking culture of the raw material for 120 h at the temperature of 37 DEG C.

Description

Technical field [0001] The invention relates to a Bacillus subtilis strain with high yield of tetramethylpyrazine, in particular to a method for producing tetramethylpyrazine by fermentation method of a Bacillus subtilis which can accumulate a large amount of 3-hydroxy-2-butanone as a precursor substance, and belongs to biological Engineering technology field. Background technique [0002] Tetramethylpyrazine (2,3,5,6-tetramethylpyrazine) is a common heterocyclic nitrogen-containing compound, widely present in food raw materials, processed foods and alcoholic beverages, and is considered to be an important class of aroma compounds. It has the aroma of roast, peanut, hazelnut and cocoa, and is often used in the blending of flavors such as baked food, cold drinks, meat, dairy products, and cigarettes. A certain amount of tetramethylpyrazine and other alkylpyrazines have also been detected in traditional Chinese liquors. They usually have a lower flavor threshold, so they are consid...

AI Technical Summary

Problems solved by technology

However, the utilization rate of this additional precursor substance by microorganisms is very low, even under the situation of higher amount of pyrazine, the utilization rate of precursor substance is not high (less than 1%)

A large amount of exogenously added precursor substance 3-hydroxy-2-butanone is added to the medium, which leads to the disturbance of microbial metabolic balance. Various enzymes in the metabolic pathway of 'de novo synthesis' precursor substances in microorganisms are inhibited by high concentrations of precursor substances, Although the concentration of the product tetramethylpyrazine has been increased to a certain extent, the utilization of various nutrients in the environment by cells conforms to the principle of "cell economics", and only a small amount of precursor substances participate in the metabolism of microorganisms under the environment conditions rich in precursor substances pathway, leading to lower utilization of precursor substances

At the same time, the addition of a large amount of exogenous precursor substances and the generation of a certain amount of products are usually toxic to microbial cells, which has an adverse effect on the industrial application of bioprocesses

In addition, the market demand for the natural precursor substance 3-hydroxy-2-butanone is still high, therefore, it is not economically feasible to increase the production of tetramethylpyrazine by adding a precursor substance

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