阅读说明：本技术 一种玉木耳富硒培养物的制作方法和用途 (Preparation method and application of Auricularia polytricha selenium-rich culture ) 是由 刘栩州 阎勇 鞠莹 黄丽玲 罗阳兰 于 2021-08-23 设计创作，主要内容包括：本发明公开了一种玉木耳富硒培养物的制作方法和用途,包括如下步骤：步骤一、制作玉木耳富硒培养物液体培养基；步骤二、制作玉木耳富硒培养物固体培养基；步骤三、在玉木耳液体培养基中接种玉木耳菌丝体(Auriculariacornea)发酵至预设时间,得到培养好的玉木耳液体菌种；步骤四、将培养好的玉木耳液体菌种接种并混合到固体培养基,发酵至预设时间后,低温干燥得到玉木耳富硒培养物。本发明制得玉木耳富硒培养物可以增加猪的料重比、提高猪肉抗氧化能力、猪肌肉硒含量和提高猪肉氧化稳定性。(The invention discloses a preparation method and application of a Auricularia polytricha selenium-rich culture, which comprises the following steps: step one, preparing a liquid culture medium of the Auricularia polytricha selenium-rich culture; step two, preparing a Auricularia polytricha selenium-rich culture solid culture medium; inoculating a Auricularia fuscospora (Auricularia cornea) in an Auricularia fuscospora liquid culture medium, and fermenting for a preset time to obtain a cultured Auricularia fuscospora liquid strain; and step four, inoculating the cultured liquid strain of the Auricularia fuscosuccinea, mixing the inoculated liquid strain with a solid culture medium, fermenting the mixture for a preset time, and drying the mixture at a low temperature to obtain the selenium-rich Auricularia fuscosuccinea culture. The prepared Auricularia polytricha selenium-rich culture can increase the feed-weight ratio of pigs, improve the oxidation resistance of pork, improve the selenium content of pork muscles and improve the oxidation stability of pork.)

1. The preparation method of the Auricularia polytricha selenium-rich culture is characterized by comprising the following steps:

step one, preparing a liquid culture medium of the Auricularia polytricha selenium-rich culture;

step two, preparing a Auricularia polytricha selenium-rich culture solid culture medium;

inoculating Auricularia polytricha mycelium (Auricularia cornea) into the Auricularia polytricha selenium-rich culture liquid culture medium, and fermenting for a preset time to obtain a cultured Auricularia polytricha liquid strain;

and step four, inoculating the cultured liquid strain of the Auricularia fuscosuccinea, mixing the inoculated liquid strain with a solid culture medium, fermenting the mixture for a preset time, and drying the mixture at a low temperature to obtain the selenium-rich Auricularia fuscosuccinea culture.

2. The method for preparing the Auricularia polytricha selenium-rich culture of claim 1, wherein the liquid culture medium comprises 0.003% of sodium selenite, 3% of glucose, 2% of corn flour, KH2PO40.25% of corn flour, MgSO40.15% of corn flour and the balance of water.

3. The method for preparing the Auricularia polytricha selenium-rich culture according to claim 1, wherein the method for preparing the Auricularia polytricha selenium-rich culture solid culture medium comprises the following steps: mixing a main material and an auxiliary material to obtain a mixture, wherein the main material comprises 85 mass percent of wheat bran and 15 mass percent of corn flour; the auxiliary material is sodium selenite, and the weight of the auxiliary material is 0.003 percent of that of the main material; sterilizing the mixture at 120 ℃ for 1 hour, introducing sterile water, and cooling to obtain the Auricularia fuscosuccinea selenium-enriched culture solid culture medium, wherein the fermentation water content in the Auricularia fuscosuccinea selenium-enriched culture solid culture medium is controlled at 60%.

4. The method for preparing the Auricularia polytricha selenium-rich culture according to claim 1, wherein in the third step, the inoculation amount of Auricularia polytricha mycelium (Auricularia cornea) is 10g/L, and the fermentation conditions are as follows: fermenting at 25 deg.C and 180RPM for 7 days.

5. The method for preparing the Auricularia polytricha selenium-enriched culture of claim 1, wherein in the fourth step, Auricularia polytricha liquid strain is mixed with Auricularia polytricha selenium-enriched culture solid culture medium at an inoculation amount of 10%, and then fermented for 15 days at 27 ℃ and relative humidity of 60%.

6. Use of the Auricularia fuscosuccinea selenium-enriched culture of any one of claims 1 to 5 as a feed additive for increasing the growth performance of pigs and the quality of pork.

7. The use of the Auricularia fuscosuccinea selenium-enriched culture of claim 6, wherein the Auricularia fuscosuccinea selenium-enriched culture is used as a feed additive for increasing the weight ratio of pig feed, improving the antioxidant capacity of pork, improving the selenium content of pork muscle and improving the oxidative stability of pork.

8. The use of the Auricularia polytricha selenium-enriched culture of claim 6, wherein the Auricularia polytricha selenium-enriched feed is further used as a feed additive for increasing the content of butyric acid in pork, increasing the expression level of MCT1mRNA in pig colon, increasing the content of GSH-Px in pig serum and liver, and reducing the content of MDA in liver.

9. The use of the Auricularia polytricha selenium-enriched culture of claim 6, wherein the Auricularia polytricha selenium-enriched culture is added in an amount of 1.2-2.4% of the total feed weight.

Technical Field

The invention belongs to the field of feeds, and particularly relates to a preparation method and application of a Auricularia polytricha selenium-rich culture (feed).

Background

Selenium-enriched feed is usually added in the animal breeding process. So that the meat of animals, such as pork, is rich in selenium to supplement the selenium in human body. For example, patent 201810432340.X discloses a selenium-rich pork and a method for feeding selenium-rich pigs. However, feeding pigs with the selenium-rich feed may cause negative effects on pig growth, such as slow pig growth, pork quality and the like, so that the development of the selenium-rich feed, determination of the effect on pig growth, namely quality, and determination of the dosage are needed.

Disclosure of Invention

In order to solve the problems, the invention discloses a preparation method and application of a Auricularia fuscosuccinea selenium-rich culture. The prepared Auricularia polytricha selenium-rich culture can increase the feed-weight ratio of pigs, improve the oxidation resistance of pork, improve the selenium content of pork muscles and improve the oxidation stability of pork.

In order to achieve the purpose, the technical scheme of the invention is as follows:

a preparation method of a Auricularia polytricha selenium-rich culture comprises the following steps:

step one, preparing a liquid culture medium of the Auricularia polytricha selenium-rich culture;

step two, preparing a Auricularia polytricha selenium-rich culture solid culture medium;

inoculating Auricularia polytricha mycelium (Auricularia cornea) into the Auricularia polytricha selenium-rich culture liquid culture medium, and fermenting for a preset time to obtain a cultured Auricularia polytricha liquid strain;

and step four, inoculating the cultured Auricularia fuscosuccinea liquid strain, mixing the inoculated Auricularia fuscosuccinea liquid strain with a solid culture medium of Auricularia fuscosuccinea selenium-rich culture, fermenting for a preset time, and drying at a low temperature to obtain the Auricularia fuscosuccinea selenium-rich culture.

In a further improvement, the liquid culture medium of the selenium-rich culture of the Auricularia polytricha comprises, by mass, 0.003% of sodium selenite, 3% of glucose, 2% of corn flour, KH2PO40.25%, MgSO40.15% and the balance of water.

Further improvement, the preparation method of the Auricularia polytricha selenium-rich culture solid culture medium comprises the following steps: mixing a main material and an auxiliary material to obtain a mixture, wherein the main material comprises 85 mass percent of wheat bran and 15 mass percent of corn flour; the auxiliary material is sodium selenite, and the weight of the auxiliary material is 0.003 percent of that of the main material; sterilizing the mixture at 120 ℃ for 1 hour, introducing sterile water, and cooling to obtain the Auricularia fuscosuccinea selenium-enriched culture solid culture medium, wherein the fermentation water content in the Auricularia fuscosuccinea selenium-enriched culture solid culture medium is controlled at 60%.

In the third step, the inoculation amount of the Auricularia (Auricularia cornea) is 10g/L, and the fermentation conditions are as follows: fermenting at 25 deg.C and 180RPM for 7 days.

In the fourth step, the Auricularia fuscosuccinea liquid strain is mixed with the Auricularia fuscosuccinea selenium-rich culture solid culture medium in an inoculation amount of 10%, and then fermented for 15 days at the temperature of 27 ℃ and the relative humidity of 60%.

The application of the Auricularia fuscosuccinea selenium-rich culture is characterized in that the Auricularia fuscosuccinea selenium-rich culture is used as a feed additive for increasing the growth performance of pigs and the quality of pork.

In a further improvement, the Auricularia polytricha selenium-rich culture is used as a feed additive for increasing the weight ratio of pig feed, improving the oxidation resistance of pork, improving the selenium content of pork muscle and improving the oxidation stability of pork.

In a further improvement, the Auricularia fuscosuccinea selenium-rich feed is also used as a feed additive for improving the content of butyric acid in pork, improving the expression level of MCT1mRNA in pig colon, improving the content of GSH-Px in pig serum and liver and reducing the content of MDA in liver.

In a further improvement, the addition amount of the Auricularia polytricha selenium-rich culture is 1.2-2.4% of the total feed weight.

The invention has the advantages that:

the prepared Auricularia polytricha selenium-rich culture can increase the feed-weight ratio of pigs, improve the oxidation resistance of pork, improve the selenium content of pork muscles and improve the oxidation stability of pork.

Drawings

Figure 1 is a graph of the relative expression of MCT1mRNA in colon in pigs fed a control diet and supplemented with 0.6%, 1.2% and 2.4% (SAC) diets, respectively.

Detailed Description

The invention is further explained with reference to the drawings and the embodiments.

Example 1

The preparation method of the Auricularia polytricha selenium-rich culture comprises the following steps:

preparing a liquid culture medium of the Auricularia polytricha selenium-rich culture: 0.003 percent of sodium selenite, 3 percent of glucose, 2 percent of corn flour and KH₂PO₄0.25％，MgSO₄0.15 percent. Then inoculating 10g/L Auricularia (Auricularia cornea) mycelium, and fermenting at 25 deg.C and 180RPM for 7 days.

Preparing a solid culture medium: wheat bran 85%, corn flour 15%, and sodium selenite 0.003%. Sterilizing at 120 deg.C for 1 hr, introducing sterile water, and cooling. The fermentation moisture is controlled at 60%.

The cultured Auricularia fuscosuccinea liquid strain is mixed with solid culture medium at an inoculum size of 10%, and fermented at 27 deg.C and relative humidity of 60% for 15 days.

Then drying the culture by low-temperature drying equipment (the temperature is controlled to be less than or equal to 55 ℃) to obtain the finished product of the Auricularia polytricha selenium-rich culture. Detecting and analyzing nutrient substances of the Auricularia polytricha selenium-rich culture (SAC).

TABLE 1 nutrient analysis of Auricularia polytricha selenium-enriched culture

Auricularia polytricha selenium-rich culture

Firstly, a feed test of the Auricularia fuscosuccinea selenium-rich culture on growth fertilization:

the 96-head ternary hybridization growth fattening pig is randomly divided into 4 treatments, and each treatment is 6 times repeated. The 4 treatments were fed control diet and test diets supplemented with 0.6%, 1.2% and 2.4% selenium-enriched culture of Auricularia fuscosuccinea, respectively. All diets met the nutritional requirements of NRC (2012). The test period was 45 days. The ambient temperature is controlled at 25-28 ℃. The test is divided into two stages, a growth stage (stage 1: 0-23 days) and a fattening stage (stage 2: 24-45 days). Daily feed intake and body weight were weighed and recorded on days 0, 23 and 45 of the trial, respectively, and the Average Daily Gain (ADG), Average Daily Feed Intake (ADFI) and feed-meat ratio (F/G) were determined. And on 45 days, taking a serum sample and a fresh excrement sample for detecting serum biochemical indexes and short-chain fatty acids.

At the end of the test, 24 pigs (1 per pen, 6 per treatment) were selected for slaughter testing. After fasting (12h), slaughter was carried out. Colonic tissue specimens were taken and stored at-80 ℃ for mRNA expression analysis. The tissues of the 10 th to 12 th intercostal longissimus muscle (LDM) (about 200g), liver and kidney of the right half of carcass were collected and immediately stored at-20 ℃ for meat quality evaluation.

TABLE 2 test diet composition

Chemical analysis and calculation:

samples were tested for crude fat (EE), Dry Matter (DM), Crude Protein (CP), ash, total phosphorus and calcium. Neutral Detergent Fiber (NDF) and Acid Detergent Fiber (ADF) contents were determined using a fiber analyzer (2010, FOSS, denmark). Total energy (GE) in diet, faeces and urine was measured using an oxygen bomb calorimeter (C2000, IKA, germany). The selenium content was quantified using inductively coupled plasma spectroscopy (ICP-MS, Thermo, USA). The concentration of Short Chain Fatty Acids (SCFA) was analyzed by ion chromatography (883, Metrohm, switzerland) according to Wu et al (2017). A commercial detection kit is adopted to detect the oxidation resistance indexes of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), Malondialdehyde (MDA) and total oxidation resistance (T-AOC). Serum High Density Lipoprotein (HDL), Low Density Lipoprotein (LDL), Glucose (GLU), Total Cholesterol (TC), and Triglyceride (TG) levels were determined using a Japanese Hitachi 3100 full-automatic biochemical analyzer and related kits.

Carcass traits and meat quality determination:

the method for measuring the length of the carcass, the weight of the carcass, marbling, the eye muscle area, the back fat thickness, the hot carcass weight and the like refers to the technical specification NY/T825-plus 2004 for measuring the carcass traits of lean-type pigs

Meat quality indicators, including meat color, pH, shear, cooking loss and drip loss, were then examined.

Relative expression of MCT1mRNA expression: the expression level of mRNA of the monocarboxylate transporter 1(MCT1) was analyzed by RT-PCR. MCT1 and beta-actin as shown in Table 3.

TABLE 3 primer information

Fresh meat simulates oxidative stability at retail display:

24 fresh meat samples were selected. Then, the fresh meat with thickness of 2.5 cm, no bone and neatly cut is respectively put on a foamed plastic tray and then wrapped by a breathable polyvinyl chloride film. Subsequently, all packaged samples were stored in an open top display box, temperature maintained at 4 ℃ and continuous lamp illumination conditions (TLD-T836W, 6200K). On days 0, 3 and 6, samples of about 10g were taken for MDA content analysis.

And (3) data analysis:

raw meat growth performance, serum biochemical indexes, short chain fatty acids, meat quality, tissue selenium concentration and MDA content were analyzed by SAS (SAS Inst.Inc., USA) software version 9.2. P <0.05 was considered statistically significant.

And (3) test results:

TABLE 4 influence of Auricularia polytricha selenium culture on growth performance of growing-finishing pigs

As shown in table 4, the feed weight ratio (p <0.05) for pigs with SAC addition was significantly lower than the control on days 1-23 of the experiment. On days 24-45 of the experiment, the weight ratio of the swine feed with 1.2% and 2.4% SAC added was significantly higher than that of the control group and 0.6% SAC added (p < 0.01). The average daily gain was higher for 1.2% and 2.4% SAC treatment than the control (p <0.05) and the weight ratio was lower for 0.6%, 1.2% and 2.4% SAC treatment than the control (p <0.05) throughout the test period.

As can be seen from table 5, addition of SAC to the ration significantly increased the butyric acid concentration for 45 days (p <0.05) compared to the control group.

TABLE 5 Effect of Auricularia fuscosuccinea selenium-rich culture on short-chain fatty acids in fresh feces

FIG. 1 effect of selenium-enriched culture of Auricularia polytricha on expression level of MCT1mRNA in colon

As shown in figure 1, the porcine colon MCT1mRNA expression (P ═ 0.04) was higher for the 1.2% and 2.4% SAC diets than for the control group.

TABLE 6 influence of selenium-enriched Auricularia polytricha culture on serum biochemical index

As can be seen from table 6, the GSH-Px content was significantly higher on day 45 in the 1.2% and 2.4% SAC groups than in the control group (p < 0.05).

TABLE 7 Effect of selenium-enriched Auricularia polytricha culture on antioxidant index of liver and longissimus dorsi

As can be seen from table 7, the addition of 2.4% SAC to the diet significantly increased the hepatic GSH-Px content (p <0.05), and the addition of 1.2% and 2.4% SAC significantly decreased the hepatic MDA content (p < 0.05). GSH-Px activity was significantly higher in the 2.4% treated group than in the control group (p < 0.05).

TABLE 8 Effect of Auricularia fuscosuccinea selenium-enriched cultures on tissue selenium content

As can be seen from table 8, the selenium content in the fattening pig LDM with the addition of 2.4% SAC was higher (p <0.05) compared to the other 3 treatments. The content of selenium in the livers of pigs fed with SAC daily ration tends to increase (p is 0.09).

TABLE 9 Effect of selenium-enriched Auricularia polytricha culture on carcass traits and meat quality

As can be seen from Table 9, the feeding of SAC at different levels had no effect on the carcass traits and meat quality of the swine.

TABLE 10 Effect of Auricularia fuscosuccinea selenium-enriched cultures on the antioxidant status of fresh meat in simulated shelf life tests

As can be seen from table 10, the fresh meat MDA content was lower in the 2.4% SAC group compared to the control group at day 6 of the simulated retail display (p < 0.05).

In conclusion, the Auricularia fuscosuccinea selenium-rich culture has good effects on promoting the growth and development of pigs, improving the oxidation resistance and the content of selenium in muscles and improving the oxidation stability of meat.

While embodiments of the invention have been described above, and not limited to the applications set forth in this specification and the embodiments, it is to be understood that the invention is capable of use in various other fields of endeavour to which this invention pertains and that various other modifications may be readily apparent to those skilled in the art, and it is therefore intended that this invention not be limited to the details shown and described herein but that the invention is not limited to the particular details shown and described without departing from the general concept as defined by the appended claims and their equivalents.