Phaeohelotium vellereum s-lwz20210623-1a and application thereof in preparation of rice fungus food

Abstract

The present application belongs to the technical field of multifunctional bacteria grain and functional food preparation. The present application provides a strain of Sanghuangporus weigelae S-LWZ20210623-1a CGMCC No. 40572. The strain has been preserved in the China General Microbiological Culture Collection Center (CGMCC) on April 12, 2023, the preservation number of the strain is CGMCC No. 40572, and the address of the center is No. 1, Yihuangyuan 3rd Road, Beijing City, Chaoyang District. The present application provides that the strain can increase the content of crude polysaccharide in the product after fermentation of rice by 1.34 times, the content of total phenols by 3.05 times, and the content of soluble protein by 14.88 times.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of multifunctional fungus grain preparation. BACKGROUND

[0002] As one of the most commonly consumed grains in daily life, rice can provide humans with nutrients such as protein, fatty acids, vitamins, and minerals. With its refinement, the pursuit of taste leads to excessive processing of rice, resulting in a large loss of nutrients. Rice is rich in polyphenols, mainly in two forms: free and bound. The bound polyphenols are much higher than the free polyphenols. Most of the phenolic substances are not easily digested and absorbed by the human body because they are combined with polysaccharides, proteins, and lipids in the cell wall in the form of bound state. In addition, the protein in rice often lacks lysine, methionine, threonine, and tryptophan, and at the same time, other amino acids cannot be fully utilized, thereby reducing the digestibility of protein and the nutritional value of grains. Rice nutrition fortification has become a problem to be solved in the rice processing industry in China.

[0003] Sanghunagporus weigelae belongs to Basidiomycota, Agaricomycetes, Hymenochaetales, Hymenochaetaceae, and Sanghuangporus, and is widely distributed in Guizhou, Hubei, Hunan, Zhejiang and other places in China. Its main host is the live standing wood or fallen wood of various broad-leaved trees. Sanghunagporus weigelae is an important medicinal resource with multiple functions such as anti-tumor and antioxidant. Sanghuangporus polysaccharide is one of the main components of Sanghuangporus that plays a pharmacological role. It is a kind of high molecular polymer formed by connecting multiple ketose or aldehyde sugar through glycosidic bond, and widely exists in fruiting bodies, mycelium and fermentation broth. Studies have shown that Sanghuangporus polysaccharide has antioxidant, anti-tumor, antibacterial, anti-inflammatory, immune regulation and other activities. Flavonoids are a kind of high content secondary metabolites, mainly existing in the mycelium and fruiting bodies of Sanghuangporus. The flavonoids required by the human body cannot be synthesized by the body itself, but can only be obtained from food. The physiological function of flavonoids has a great effect on human health. In recent years, with the increasing understanding of human health, the research on flavonoid extraction using edible fungi as raw materials has not only been paid more and more attention, but also gradually become an important topic in the field of nutrition. SUMMARY

[0004] Therefore, the application provides a Sanghuangporus weigelae S-LWZ20210623-1a CGMCC No.40572.

[0005] The application also provides a composition comprising Sanghuangporus weigelae S-LWZ20210623-1a CGMCC No.40572. The strain has been preserved in the China General Microbiological Culture Collection Center (CGMCC) on April 12, 2023, and the preservation number of the strain is CGMCC No.40572. The address of the CGMCC is No.1, Michen West Road, Haidian District, Beijing. The application also provides a composition comprising Sanghuangporus weigelae S-LWZ20210623-1a CGMCC No.40572.

[0006] The application finally provides an application of Sanghuangporus weigelae S-LWZ20210623-1a in preparing rice fungus food.

[0007] The application at least comprises the following beneficial effects:

[0008] Firstly, the content of crude polysaccharide in the fermentation product of rice inoculated with Sanghuangporus weigelae is significantly improved.

[0009] Secondly, the content of flavonoids in the fermentation product of rice inoculated with Sanghuangporus weigelae is significantly improved, such as hesperetin and luteolin which have various biological activities, such as antioxidant, ototoxicity resistance, anti-inflammatory, anti-atherosclerosis, and anti-hypertension.

[0010] Thirdly, the contents of lysine, threonine, tryptophan, and methionine in the fermentation product of rice inoculated with Sanghuangporus weigelae are all increased to different degrees, so that the essential amino acids lacking in rice are supplemented, and the nutritional value of protein is improved. DETAILED DESCRIPTION

[0011] Embodiment 1

[0012] 1. Obtaining, isolating, and identifying of the strain

[0013] The strain was collected from the Jiangxi Lushan National Nature Reserve on June 23, 2021, and was obtained from the fresh fruiting body growing on the branches of Corylus heterophylla living trees by using tissue isolation method, and was named as strain S-LWZ20210623-1a. In the tissue isolation method, fresh fruiting bodies without mildew or insect damage were selected, the surface was sterilized with 75% alcohol, and about 0.5 cm 3 tissue of the fungus meat part was selected and inoculated on the surface of potato agar medium (PDA) medium, and was placed in a constant temperature incubator at 26℃ for 10-15 days. After purification, the culture was incubated at 26℃ for 10-15 days.

[0014] The DNA of S-LWZ20210623-1a was extracted by using a fungal genome rapid extraction kit by cracking method, and the ITS sequence thereof was obtained by PCR amplification, the sequence information of which is shown as SEQ ID NO. 1 in the sequence table, by comparing with the NCBI database BLAST and referring to the DNA barcode library construction phylogenetic tree of Sanghuangporus, combined with morphological analysis, it is determined that the strain is identified as Sanghuangporus weigelae.

[0015] Sanghuangporus weigelae S-LWZ20210623-1a has been preserved in the China General Microbiological Culture Collection Center (CGMCC) on April 12, 2023, the strain preservation number of which is CGMCC No. 40572, and the address of the center is No. 1, Beichen West Road, Haidian District, Beijing.

[0016] 2. Preparation of mother culture medium and activation of strain

[0017] The preparation formula and method of the mother culture medium (PDA) are as follows: 300g / L of boiled potato liquid, 20g / L of glucose, 5g / L of proteose peptone, 20g / L of agar, 1g / L of potassium dihydrogen phosphate, and 0.5g / L of magnesium sulfate heptahydrate, with natural pH. After stirring, pour it into a conical flask, sterilize at 121℃ for 20min, and when the temperature decreases to room temperature, add 0.1% of streptomycin sulfate and ampicillin solution.

[0018] The Sanghuangporus weigelae S-LWZ20210623-1a preserved at low temperature obtained in step (1) is transferred to the mother culture medium (PDA) culture medium described above for subculture, and is cultured in a incubator at 26℃ for 10 days, to obtain the activated Sanghuangporus weigelae mother strain.

[0019] 3. Preparation of rice fungus food:

[0020] Preparation of solid culture medium: wash the rice clean, soak in distilled water for 24h, take out and drain the surface water, divide into 15x30x5C polypropylene fungus bags, add 40% of the weight of the rice in distilled water, cover with 3.8cm sponge, 4x125 sealing film and 0.22μm microporous filter film in turn, sterilize at 121℃ for 2.5h, and cool to room temperature to obtain the rice solid culture medium.

[0021] Inoculation culture: the activated strain S-LWZ20210623-1a mother bell in step (2) was inoculated into the above rice solid culture medium, a sterile puncher was used to make a 6mm diameter fungus block, which was inoculated into PDA culture medium and then placed in a constant temperature incubator at 26°C for 45 days.

[0022] Preparation of fungus grain: after the mycelium grew throughout the culture medium, it was dried at 40°C to a constant weight, ground with a grinder and sieved through a 90 mesh sieve to obtain the rice functional fungus grain, which was stored at -80°C for later use.

[0023] Comparative Example 1

[0024] Preparation of control group rice raw grain: the rice was washed clean, soaked in distilled water for 24h until the kernels became soft, then taken out and drained the surface water, divided into 15x30x5C polypropylene fungus bags, added 40% of the weight of the rice with distilled water, covered with a 3.8cm sponge, 4x125 sealing film and a microporous filter film with a pore size of 0.22μm, successively stacked and sealed, sterilized at 121°C for 2.5h and then cooled to room temperature to obtain the rice solid culture medium. The obtained solid culture medium was dried at 40°C to a constant weight, ground with a grinder and sieved through a 90 mesh sieve to obtain the control group raw grain, which was stored at -80°C for later use.

[0025] Experimental Example 1

[0026] 1. Extraction and content determination of crude polysaccharides in rice solid-state fermentation products inoculated with Phaeophlebia laibinensis

[0027] Determination by the following method:

[0028] Crude polysaccharides were extracted by water extraction and alcohol precipitation method (Jiang, He, Niu, Wan, et al. Optimization of extraction process of Ganoderma lucidum spore polysaccharides and analysis of monosaccharide composition and antioxidant activity [J]. Chinese Journal of Food Science, 2021, 21(04): 159-167.)

[0029] The content of crude polysaccharides was determined by the phenol-sulfuric acid method (Zuo, Yang, Xing, Han, Gu. Research on determination method of total sugar content of edible fungi. Journal of Edible Fungi, 2021, 15(4): 57-61)

[0030] 2. Determination of total phenol content in rice solid-state fermentation products inoculated with Phaeophlebia laibinensis

[0031] The total phenol content in the sample was determined by Folin phenol colorimetry (Wang, Lu, Yan, Fu, Song, Yuan, Zhou. Effects of growth duration on the nutritional, active ingredients and antioxidant activity of segment wood cultivated Baum Phaeophlebia laibinensis. Mycosystema, 2021, 40(3): 668-680)

[0032] 3. Determination of soluble protein content in rice fermented by Phaeophlebia subfastidiosa: BCA protein content test kit was used

[0033] 4. Determination of differential metabolites in rice fermented by Phaeophlebia subfastidiosa. Non-targeted metabolomics determination method (An MJ, Hong DS, Chang DD, Zhang CY, Fan H, Wang KY. Polymer amendment regulates cadmium migration in cadmium contaminated cotton field: Insights from genetic adaptation and phenotypic plasticity. Science of the Total Environment, 2022, 808: 151075) was used

[0034] The contents of crude polysaccharides, total phenols, and soluble proteins in the rice fermented by Phaeophlebia subfastidiosa were detected, and the specific data are shown in Table 1:

[0035] Table 1. Active substance content

[0036]

[0037] As can be seen from the above table, the contents of crude polysaccharides, total phenols, and soluble proteins of the three replicates of the example are significantly higher than those of the comparative example, indicating that inoculation of Phaeophlebia subfastidiosa has a significant effect on increasing the contents of crude polysaccharides, total phenols, and soluble proteins in the original grain.

[0038] Non-targeted detection of active substance content in rice fermented by Phaeophlebia subfastidiosa showed that Hesperetin in flavonoids has various biological activities, such as antioxidant, anti-ototoxicity, anti-inflammatory, anti-atherosclerosis, anti-hypertensive, etc.; Luteolin has various pharmacological effects such as antioxidant, anti-inflammatory, and anti-tumor, etc.

[0039] In addition, Phaeophlebia subfastidiosa can significantly increase the content of Genistin, an isoflavone compound, in the original grain. Isoflavones are a class of plant estrogens with wide biological activities, which can scavenge free radicals in the body, slow down or eliminate the absorption of external stimulating factors such as carcinogens by the body, and have been successfully developed in anti-aging, anticancer, and prevention of cardiovascular diseases, etc.

[0040] Compared with the control, the content of β-Caryophyllene, a bicyclic sesquiterpene with anti-inflammatory, antioxidant, and anti-anxiety pharmacological activities, in the fermentation product of Phlebia flabella inoculated with Phlebia flabella was significantly improved. In addition, Nootkatone and Capsidiol were also significantly improved.

[0041] Compared with the control, the content of β-Sitosterol, which has a cholesterol-lowering effect, in the fermentation product of Phlebia flabella inoculated with Phlebia flabella was significantly improved, further enhancing the functional value of the fungus-grain.

[0042] Compared with the control, the contents of lysine and tryptophan in the fermentation product of Phlebia flabella inoculated with Phlebia flabella were significantly improved, effectively supplementing the lack of lysine, methionine, threonine, and tryptophan in rice, allowing other amino acids to be fully utilized. More importantly, the lysine content of rice was strengthened, lysine being the first limiting amino acid of cereal protein, thereby improving the protein digestibility and nutritional value of the raw grain.

[0043] The lysines include: β-Alanyl-L-lysine, N-Alpha-acetyllysine, N6-(L-1,3-Dicarboxypropyl)-L-lysine, L-Methionine, and L-Threonine.

[0044] The tryptophans include: N-Acetyl-D-tryptophan and Tryptophan.

[0045] The specific data is shown in Table 2, and the percentage increase of the examples compared with the control is shown in Table 3:

[0046] Table 2 Quantification of differential metabolites in examples and controls

[0047]

[0048]

[0049] Note: Control / example value: fold difference of metabolites in different groups

[0050] Table 3 Increased content of examples compared with the control

[0051]

[0052] Note: % increase values: % increase of example over comparative example

Claims

1. Sanghuangporus weigelae S-LWZ20210623-1a, with the accession number of CGMCC No. 40572.

2. Composition, characterized in that, The patent application of claim 1 Sanghuangporus weigelae S-LWZ20210623-1a.

3. The Phaeosaccardinium described in claim 1 Sanghuangporus weigelae Use of S-LWZ20210623-1a in preparing rice fungus food.

4. The Phaeosaccardinium sp. of claim 1 Sanghuangporus weigelae Use of S-LWZ20210623-1a in increasing the content of rice fermentation products, characterized in that, The rice fermentation product is one or more of flavonoids, isoflavonoids, total phenols, soluble proteins, sesquiterpenes and phytosterols; The isoflavonoids include genistin; The soluble proteins include one or more of β-alanyl-L-leucine, N6-(L-1,3-dicarboxypropyl)-L-lysine, N-acetyl-L-lysine, methionine, threonine, N-acetyl-D-tryptophan and tryptophan; The sesquiterpenes include one or more of caryophyllene, cycloart-22-ene and capsaicin alcohol; The flavonoids include one or more of hesperetin and luteolin.

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