阅读说明：本技术 含鸟氨酸的短肽及其应用 (Short peptide containing ornithine and application thereof ) 是由 孔青 于 2017-05-24 设计创作，主要内容包括：本发明提供了一种含鸟氨酸的短肽及其应用,属于生物技术领域,该短肽能够有效应用于抑制黄曲霉的生长和黄曲霉毒素的生物合成中。该短肽具有如下通式结构：<Image he="112" wi="476" file="DDA0002192316900000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>其中,X代表鸟氨酸,n＝1,m为1-8的正整数。本发明能够应用于黄曲霉生长的抑制中。(The invention provides a short peptide containing ornithine and application thereof, belonging to the technical field of biology. The short peptide has the following general structure: wherein, XRepresents ornithine, n is 1, and m is a positive integer from 1 to 8. The invention can be applied to the inhibition of the growth of aspergillus flavus.)

1. An ornithine-containing short peptide, wherein the short peptide has the following general structure:

wherein, X represents ornithine, n is 1, and m is a positive integer from 1 to 8.

2. The short peptide according to claim 1, wherein the amino acid sequence of the short peptide is selected from any one of SEQ ID NO.17, SEQ ID NO.18, SEQ ID NO.19, SEQ ID NO.20, SEQ ID NO.21, SEQ ID NO.22, SEQ ID NO.23, and SEQ ID NO.24 of the sequence Listing.

3. Use of a short peptide according to claim 1 or 2 in inhibiting the growth of Aspergillus flavus on a solid medium.

4. Use of the short peptide of claim 1 or 2 for inhibiting the growth of aspergillus flavus and the biosynthesis of aflatoxin in crop storage.

5. An antibacterial composition comprising at least one short peptide according to claim 1 or 2 in a therapeutically or prophylactically effective amount and at least one pharmaceutically acceptable carrier.

Technical Field

The invention belongs to the technical field of biology, and particularly relates to an ornithine-containing short peptide and application thereof.

Background

Aflatoxins are mainly produced by aspergillus flavus and aspergillus parasiticus, have strong toxicity, teratogenicity and carcinogenicity, and crops such as peanuts, corns, rice, cottonseeds, nuts and the like are easily polluted by aflatoxins. Aflatoxin B1 is the most toxic natural carcinogen known to cause liver cancer.

At present, physical, chemical and biological methods are commonly used to remove aflatoxin in raw materials. Physical methods such as heating, adsorption, extraction, gamma ray irradiation, ultraviolet irradiation, and the like. Chemical methods such as treatment with ozone, ammonia, chlorine, hydrogen peroxide, formaldehyde, and the like. Biological methods such as detoxification by microbial fermentation of raw materials, inhibition of toxin production by plant extracts, etc. However, each method has limitations, or because the nutrients of the raw materials are lost, or because expensive equipment is required, etc. For example, aflatoxin has a very stable structure and decomposes at 270 ℃, for example, the higher the temperature and the longer the heating time are, the higher the aflatoxin removal rate is, if the heat treatment is adopted, but obviously, the heating method easily causes nutrient loss of materials and needs high-pressure resistant equipment. Therefore, there is an urgent need to provide an effective method for inhibiting the biosynthesis of aflatoxins.

Disclosure of Invention

The invention provides a short peptide containing ornithine and application thereof, and the short peptide can be effectively applied to growth of aspergillus flavus and biosynthesis of aflatoxin.

In order to achieve the above objects, one aspect of the present invention provides an ornithine-containing short peptide having the following general structure:

wherein, X represents ornithine, n is 1, and m is a positive integer from 1 to 8.

As a preferred technical scheme, the amino acid sequence of the short peptide is selected from any one of SEQ ID NO.17, SEQ ID NO.18, SEQ ID NO.19, SEQ ID NO.20, SEQ ID NO.21, SEQ ID NO.22, SEQ ID NO.23 and SEQ ID NO.24 in a sequence table.

The invention also provides application of the short peptide in inhibiting the growth of aspergillus flavus on a solid culture medium.

In another aspect, the invention provides an application of the short peptide according to any one of the above technical schemes in inhibiting growth of aspergillus flavus and biosynthesis of aflatoxin in crop storage.

In yet another aspect, the present invention provides an antibacterial composition comprising at least one short peptide according to any one of the above technical schemes in a therapeutically or prophylactically effective amount and at least one pharmaceutically acceptable carrier.

Compared with the prior art, the invention has the advantages and positive effects that:

1. the short peptide provided by the invention is obtained by first separating from bacillus megaterium fermentation liquor, and has a good inhibition effect on aflatoxin.

2. The short peptide provided by the invention not only has a remarkable inhibition effect on the growth of aspergillus flavus on a solid culture medium, but also has a remarkable inhibition effect on the growth of aspergillus flavus and the biosynthesis of aflatoxin in crop storage, wherein the growth of aspergillus flavus can be remarkably inhibited by partial short peptide at the concentration of 2 mg/mL.

Drawings

FIG. 1 is a diagram showing the purification of components of a Bacillus megaterium fermentation broth separated by Sephadex G-25 chromatography as provided in example 1 of the present invention, including two components A1 and A2;

FIG. 2 is a diagram of the separation and purification of the A2 fraction by reversed-phase high performance liquid chromatography, which is provided in example 1 of the present invention and comprises 9 fractions B1-B9;

FIG. 3 is a combined liquid chromatogram of each short peptide in Bacillus megaterium provided in example 1 of the present invention, in which (a) is a liquid chromatogram of the B6 fraction obtained by reverse-phase HPLC; (b) mass spectrum of short peptide with m/z 942.9606; (c) mass spectrum of short peptide with m/z 938.0045.

FIG. 4 is a graph showing the bacteriostatic effect of 24 kinds of short peptides on a solid medium according to example 2 of the present invention;

FIG. 5 is a graph showing the bacteriostatic effects of Asp-Orn, Asp-Asn and Asp-Asp-Asn in different configurations provided in example 3 of the present invention in crop storage;

FIG. 6 shows the effect of L-Asp-L-Orn on the morphology of Aspergillus flavus hyphae observed under a scanning electron microscope provided in example 3 of the present invention;

FIG. 7 shows the effect of L-Asp-L-Orn on the morphology of Aspergillus flavus hyphae observed under a transmission electron microscope in example 3 of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.