Irpex lacteus nd6 and application thereof
By fermenting the crumbs of Caragana korshinskii with white sac fungus, the problem of Caragana korshinskii cellulose being difficult for animals to digest was solved, the nutritional value and palatability of Caragana korshinskii feed were improved, and the growth performance and antioxidant capacity of ruminants were promoted.
Patent Information
- Application Number
- CN202510796199.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-16
- Publication Date
- 2025-09-16
AI Technical Summary
The high content of lignocellulose in Caragana korshinskii branches results in poor palatability and makes it difficult for ruminants to digest and utilize it, limiting its large-scale promotion as a feed resource.
Irpex lacteus nd6 was used to ferment the shredded Caragana korshinskii. By optimizing the culture conditions and sterilization methods, the nutritional content of Caragana korshinskii and its ability to degrade lignocellulose were improved, and fermented feed suitable for pigs, cattle and sheep was prepared.
It significantly increased the crude protein content of caragana fermented feed, reduced the neutral detergent fiber and acid detergent fiber content, enhanced the growth performance and antioxidant capacity of pigs, and improved the palatability and conversion rate of feed.
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Figure CN120648566A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of biotechnology, in particular to an Irpex lacteus nd6 strain and an application thereof. Background Art
[0002] Caragana is the common name for cultivated species of the genus Caragana in the Leguminosae family. With its well-developed root system and strong resistance to adversity, it is one of the main windbreak and sandfixing tree species in desert steppes. Soil and water conservation and sand fixation afforestation are being carried out in Northwest China, North China, and Northeast China, with large-scale artificial planting of Caragana, achieving excellent ecological benefits such as windbreak and sand fixation, soil and water conservation, and vegetation restoration. However, with the rapid expansion of Caragana plantations and the increase in forest age, the failure to timely prune Caragana trees has led to varying degrees of lignification and even death in early-planted Caragana trees. Timely pruning is necessary to ensure their ecological benefits. Pruning can promote the sprouting of a large number of branches at the base of the plant stump, exerting reproductive compensation capacity, promoting root growth and renewal, and is an economical and effective measure to address the premature aging and death of Caragana trees. In recent years, research on the use of pruning caragana branches as feed has largely focused on this. However, the technical bottleneck preventing widespread adoption is the high lignocellulose content in caragana branches, which is difficult for animals to digest and absorb. This results in poor palatability and difficulty for ruminants to digest and utilize. Therefore, the scientific and rational development and utilization of caragana feed resources is of great significance for alleviating feed resource shortages, promoting the healthy development of agriculture, forestry, and animal husbandry, and achieving the organic integration of economic, social, and ecological benefits of caragana resources.
[0003] White rot fungi are a group of fungi that use plants as a matrix and cause white decay in dead plants. In the process of decomposing cellulose, white rot fungi will produce corresponding enzyme systems to oxidize and decompose cellulose, and have a strong ability to degrade cellulose. In September 2023, the project team members conducted a large-scale fungal diversity survey in the Maowusu Desert in Inner Mongolia, and found a large dominant white rot fungus, Irpex lacteus, on the dead branches of Caragana korshinskii, the main local windbreak and sand-fixing tree species. The present invention conducts a preliminary study on the biological characteristics of Irpex lacteus mycelium and its ability to degrade Caragana korshinskii debris, providing a theoretical basis and technical support for the application of Irpex lacteus in the use of Caragana korshinskii. Summary of the Invention
[0004] The purpose of the present invention is to provide a strain of Irpex lacteus nd6 and applications thereof.
[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:
[0006] The present invention provides a strain of Irpex lacteus nd6, which is deposited in the General Microbiology Center of the China Culture Collection Administration, with the address being No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, with a deposit date of March 10, 2025, and a deposit number of CGMCC No. 41795.
[0007] The present invention also provides a method for culturing the white sac rake tooth fungus nd6, comprising the following steps:
[0008] (1) inoculating the white cyst nd6 into an activation medium for activation culture;
[0009] (2) The activated white sac rake tooth fungus nd6 in step (1) is inoculated into a propagation medium for propagation culture.
[0010] Preferably, the activation culture medium is prepared from the following components in mass concentrations: peptone 18-22 g / L, maltose 1.5-2.5 g / L, potassium dihydrogen phosphate 1.5-2.5 g / L, magnesium sulfate 0.8-1.2 g / L, and agar powder 18-22 g / L.
[0011] Preferably, the conditions for the activation culture and the expansion culture are both 28-32° C. and pH 5.4-5.6.
[0012] Preferably, the enrichment medium is prepared from the following components in parts by weight: 97-99 parts of buckwheat, 0.5-1.5 parts of gypsum, and 0.5-1.5 parts of sugar; the water content of the enrichment medium is 63-67%.
[0013] The present invention also provides the use of the white capsule rake tooth fungus nd6 in decomposing Caragana korshinskii.
[0014] The present invention also provides a caragana fermented feed. The preparation method of the caragana fermented feed comprises the following steps: sterilizing caragana shredded debris and then inoculating the white capsule fungus ND6 for fermentation.
[0015] Preferably, the sterilization method is: sterilization at 78-82° C. for 5-7 hours; and the fermentation time is 50-60 days.
[0016] Preferably, the water content of the sterilized Caragana kaki shredded debris is 63-67%; and the inoculation mass percentage concentration of the white capsule rake tooth fungus nd6 is 4-9%.
[0017] The present invention also provides the use of the feed in preparing feed for pigs, cattle or sheep.
[0018] Preferably, the pig feed is eight-browed pig feed; the cattle feed is Mongolian cattle feed; and the sheep feed is Hulunbuir sheep feed.
[0019] Compared with the prior art, the present invention has the following beneficial effects:
[0020] The present invention isolated a strain of Irpex lacteus nd6 from the dead branches of Caragana korshinskii, and conducted a preliminary study on the biological characteristics of the strain and its effect on the nutrition and lignocellulose of Caragana korshinskii after degrading Caragana korshinskii. Single-factor and orthogonal experiments were used to explore the biological characteristics of the fungus, and at the same time, the effect of the fermentation of the fungus on the nutritional changes and lignocellulose degradation ability of Caragana korshinskii was tested. The present invention used the obtained Irpex lacteus nd6 to ferment Caragana korshinskii crumbs, and the results showed that the conventional nutrition of most Caragana korshinskii was significantly improved, among which the crude protein content, an important indicator of feed, was significantly higher than the original sample, and the neutral detergent fiber, acid detergent fiber and acid detergent lignin contents were significantly lower than the original sample group, with degradation rates reaching 8.10%, 10.46% and 18.67% respectively, indicating that the use of Irpex lacteus nd6 to degrade Caragana korshinskii lignocellulose has good application potential.
[0021] The present invention uses fermented caragana in the breeding of eight-browed pigs. Experimental results show that feed supplemented with fermented caragana has a more excellent growth-promoting effect on the pigs and also improves the pigs' antioxidant capacity. Furthermore, the fermented caragana prepared by the present invention can also be used in the preparation of cattle and sheep feed. The addition of fermented caragana can enhance feed palatability, improve feed conversion rate, and solve the problem of monotonous forage in winter. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.
[0023] Figure 1 This is the effect of different carbon sources on the mycelial growth of White Capsule Rake Tooth Fungus.
[0024] Figure 2 This shows the growth of mycelium of White Capsule Rake Tooth Fungus under different carbon sources.
[0025] Figure 3 This is the effect of different nitrogen sources on the mycelial growth of White Capsule Raketooth Fungus.
[0026] Figure 4 This is the growth of mycelium of White Capsule Rake Tooth Fungus under different nitrogen sources.
[0027] Figure 5 This is the effect of different pH of the mycelium of White Capsule Rake Tooth Fungus on mycelial growth.
[0028] Figure 6 The growth of mycelium of White Capsule Rake Tooth Fungus under different pH conditions.
[0029] Figure 7 This is the effect of different temperatures on the growth of mycelium of White Capsule Rake Tooth Fungus.
[0030] Figure 8 The growth of mycelium of white capsule fungus at different temperatures.
[0031] Figure 9 This is the growth of mycelium and cords of White Capsule Rake Tooth Fungus on different culture medium formulas.
[0032] Figure 10 This is the effect of different stock culture media on the mycelial growth of White Capsule Rake Tooth Fungus.
[0033] Figure 11 The growth of mycelium of white capsule fungus on different culture medium formulations.
[0034] Biological Deposit Description
[0035] White capsule rake tooth fungus nd6, Latin name Irpex lacteus;
[0036] The strain is deposited in the General Microbiology Center of China Culture Collection Administration: the address is No. 3, No. 1 Beichen West Road, Chaoyang District, Beijing. The deposit date is March 10, 2025, and the deposit number is CGMCC No.41795. DETAILED DESCRIPTION
[0037] The technical solutions provided by the present invention are described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.
[0038] Example 1
[0039] 1 Materials and Methods
[0040] 1.1 Test materials
[0041] The strain of white cyst nd6 has a preservation number of CGMCC No.41795.
[0042] The strain was activated using PDA medium: 200 g potatoes, 20 g glucose, 20 g agar powder, natural pH, and 1 L water.
[0043] Single factor and orthogonal test culture medium: 20 g carbon source, 2 g nitrogen source, 2 g potassium dihydrogen phosphate, 1 g magnesium sulfate, 20 g agar powder, 1 mol / L hydrochloric acid and 1 mol / L sodium hydroxide for adjusting pH, 1 L water.
[0044] Formula of culture medium for fungus propagation (mass fraction): corn, sorghum, buckwheat and millet account for 98% respectively, sugar 1%, gypsum 1%, water content 60%-65%. Mix the secondary culture medium according to the above formula and put it into a 17cm×33cm×0.05cm cultivation bag with 1kg of material.
[0045] 1.2 Biological characteristics research
[0046] PDA solid medium was used as the strain activation medium. After transfer, mycelial biological characterization experiments were conducted until the colonies filled the culture plates. A 10 mm diameter borer was used to extract a mycelial block of the fungus nd6 and inoculate it into the center of a culture medium with adjusted carbon source, nitrogen source, pH, and temperature. For both single-factor and orthogonal experiments, 10 replicates were set for each treatment. Colony diameters were measured using the cross-hatch method until the mycelium filled the plate. Mycelial morphology and growth were recorded and photographed.
[0047] 1.2.1 Carbon source experiment
[0048] Fructose, maltose, glucose, sucrose, lactose and starch were added as test carbon sources respectively, and no carbon source was added as the control group. The concentration of all the carbon sources was 20 g / L. After inoculation, the cells were cultured in a constant temperature incubator at 25°C in the dark.
[0049] 1.2.2 Nitrogen source experiment
[0050] Peptone, sodium nitrate, glutamic acid and aspartic acid were added as test nitrogen sources respectively, and no nitrogen source was added as the control group. The concentration of each nitrogen source was 2 g / L. After inoculation, the cells were cultured in a constant temperature incubator at 25°C in the dark.
[0051] 1.2.3 pH experiment
[0052] The basal culture medium used glucose and peptone as fixed carbon and nitrogen sources. The initial pH was adjusted with 1.0 mol / L HCl and 1.0 mol / L NaOH solutions, and 8 pH gradients were set: 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, and 8.0.
[0053] 1.2.4 Temperature experiment
[0054] The basal culture medium uses glucose and peptone as fixed carbon and nitrogen sources. After inoculation, the culture medium is placed in a constant temperature incubator at 10°C, 15°C, 20°C, 25°C, 30°C, 35°C and 40°C in the dark.
[0055] 1.2.5 Orthogonal experiment
[0056] According to the results of the four single-factor experiments on carbon source, nitrogen source, pH and temperature, three optimal levels of each factor were selected to establish a four-factor three-level orthogonal experiment.
[0057] 1.3 Research on culture medium for bacterial expansion
[0058] Based on relevant literature and the nutritional characteristics of mycelium, five propagation media were designed: 98% (by mass) sorghum, corn, buckwheat, wheat, and millet, 1% gypsum, 1% sugar, 65% water, and a natural pH. The propagation media were mixed according to the above recipe, with 30g of medium placed in each petri dish. Ten replicates were used for each treatment.
[0059] 1.4 Degradation of Caragana korshinskii by Pseudomonas aeruginosa nd6
[0060] Based on the weight of fresh samples of commercially available Caragana korshinskii crumbs, the following treatments were set: a control group (CK) with no additives, and treatment groups consisting of aerobic fermentation of Caragana korshinskii crumbs with Albizia spp. (autoclaved for 2 hours) and pasteurized (80°C sterilized for 6 hours). The fungus, cultured on buckwheat medium, was inoculated at a 5% inoculum into the culture media (65% moisture content) in the Albizia spp. and pasteurized groups, respectively. Samples were taken 56 days after full mycelium growth to investigate changes in lignocellulose and nutritional components in Caragana korshinskii following the two sterilization conditions compared to the original sample.
[0061] After drying at 65°C for 48 h, the dry matter (DM), crude fat (EE), crude ash (Ash), calcium (Ca), and phosphorus (P) contents were determined according to the methods of GB / T 6435-2014, GB / T 6433-2006, GB / T 6438-2007, GB / T 6436-2018, and GB / T 6437-2018, respectively. The crude protein (CP) content was determined using an automatic Kjeldahl nitrogen analyzer (model, Jinan Haineng Instrument Co., Ltd.). The neutral detergent fiber (NDF), acid detergent fiber (ADF) and acid insoluble lignin (ADL) contents were determined using an automatic fiber analyzer (A2000i, ANKOM, USA) with reference to the method of Van Soest (VAN SOEST PJ, ROBERTSON JB, LEWIS BA. Methods for dietary fiber, neutral detergent fiber, and nonstarch polysaccharides in relation to animal nutrition [J]. Journal of Dairy Science, 1991, 74(10): 3583-3597).
[0062] 1.5 Data Processing and Analysis
[0063] The experimental data were processed using Excel 2019, and one-way ANOVA was performed using SPSS 22.0 statistical software, followed by Duncan's multiple comparison test. P < 0.05 indicated a significant difference. The experimental data results were expressed as mean ± standard deviation.
[0064] 2 Results and Analysis
[0065] 2.1 Single-factor test results
[0066] 2.1.1 Carbon source test
[0067] White capsule rake tooth fungus can utilize several tested carbon sources. Mycelium can grow on different carbon source media, and the growth conditions are significantly different. When the carbon source is maltose and glucose, the mycelium grows fastest, significantly higher than the control group; when the carbon source is lactose, the mycelium grows the slowest. The order of mycelium growth rate from large to small is maltose (16.2±1.4) = glucose (16.2±0.64) > starch (15.9±0.9) > fructose (14.8±0.38) > sucrose (14.4±0.62) > lactose (13.8±0.4) > control group (11.7±0.9) ( Figure 1 Mycelial growth characteristics: When maltose is used as the carbon source, the mycelium of the white capsule rake tooth fungus is white and dense, and the mycelium grows well, followed by glucose and starch. When lactose is used as the carbon source, the mycelium growth is the worst ( Figure 2 ). Comprehensive analysis showed that maltose was the most suitable carbon source for the mycelium of Albizia serrata.
[0068] 2.2.2 Nitrogen source test
[0069] White capsule rake tooth fungus can utilize several tested nitrogen sources, and mycelium can grow on different nitrogen source media, and the mycelium growth conditions are significantly different. When the nitrogen source medium is glutamic acid, the mycelium growth rate is the fastest, significantly higher than the control group; when sodium nitrate is used as the nitrogen source, the growth condition is the worst, and its mycelium growth rate is significantly lower than the control group. The order of growth rate from large to small is glutamic acid (16.72±0.76a)>aspartic acid (15.58±0.51b)>peptone (12.1±0.35c)>control group (8.52±0.82d)>sodium nitrate (8.22±0.40d) ( Figure 3 Mycelial growth characteristics: When peptone is used as the nitrogen source, the mycelium of the white capsule rake tooth fungus is white and dense, and the mycelium grows well, followed by glutamic acid and aspartic acid. The mycelial growth is the worst when sodium nitrate is used as the nitrogen source ( Figure 4 ). Comprehensive analysis showed that peptone was the most suitable nitrogen source for the mycelium of Albugo serrata.
[0070] 2.2.3 pH test
[0071] White capsule rake tooth fungus can grow in pH conditions ranging from 4.5 to 8.0, demonstrating strong adaptability. However, its mycelial growth rate varies significantly within this range, particularly in the pH range of 4.5 to 6.0, where it exhibits rapid growth, while growth is relatively slow in the pH range of 7.0 to 8.0. This suggests that white capsule rake tooth fungus mycelium is well-suited to growth in slightly acidic environments. Mycelial growth rates are similar at pH values of 5.5 and 6.0. The growth rates of mycelium in different pH media were as follows: 4.5 (14.5 ± 0.09) > 5.0 (14.1 ± 0.14) > 5.5 (13.5 ± 0.33) = 6.0 (13.49 ± 0.32) > 6.5 (12.8 ± 0.85) > 7.0 (11.74 ± 0.08) > 7.5 (10.65 ± 0.10) > 8.0 (10.33 ± 0.20) ( Figure 5 Mycelial growth characteristics: Under the condition of pH 5.5, the mycelium of white capsule rake tooth fungus is white and dense, and the mycelium grows well, followed by pH 4.5 and 5.0, and the worst is pH 8.0 ( Figure 6 ). Comprehensive analysis showed that pH 5.5 was the most suitable pH for the growth of the mycelium of White Capsule Rake Tooth Fungus.
[0072] 2.2.4 Temperature test
[0073] White capsule rake tooth fungus can grow at different temperatures, but the differences are obvious. The mycelium grows faster between 25℃ and 35℃, and the growth rate is fastest at 35℃, which is significantly higher than other temperatures. The growth is slowest at 10℃. The growth rate of mycelium at different temperature gradients is as follows: 35℃ (13.51±0.44) > 30℃ (12.69±0.81) > 25℃ (9.66±0.56) > 40℃ (8.65±0.81) > 20℃ (7.11±0.26) > 15℃ (4.57±0.23) > 10℃ (2.55±0.42) ( Figure 7 Mycelial growth characteristics: The mycelium of the white capsule rake tooth fungus is white and dense at 30℃, and the mycelium grows best, followed by 35℃ and 25℃, and the worst is 10℃ ( Figure 8 ). Comprehensive analysis showed that 30℃ was the optimum temperature for the growth of mycelium of White Capsule Rake Tooth Fungus.
[0074] 2.3 Orthogonal test results
[0075] Based on the results of the single-factor test, an orthogonal analysis with 4 factors and 3 levels was established to conduct an orthogonal test. The results showed that there were significant differences in the mycelial growth rate. The mycelial growth rate of group 4 (D) was the fastest, significantly higher than that of the other 8 groups, and the mycelial growth rate of group 9 (I) was the slowest. The order of mycelial growth rate was D>F>B>G>H>C>A>E>I (Table 1). Mycelial growth characteristics: The mycelial growth of group 1 (A) was white and dense, and the mycelial growth was the best, significantly better than that of the other groups ( Figure 9 The results showed that the range r of the four factors were temperature (3.1), nitrogen source (1.7), carbon source (1.26) and pH (1.05), respectively. The main factor affecting the growth of the mycelium of the white capsule rake tooth fungus was temperature. The order of the mean temperature from large to small was K2 (49.12) > K3 (48.43) > K1 (39.82), the order of the mean nitrogen source from large to small was K1 (45.09) > K2 (48.43) > K3 (5.1), the order of the mean carbon source from large to small was K2 (47.88) > K1 (45.39) > K3 (44.1), and the order of the mean pH from large to small was K1 (47.00) > K1 (46.52) > K3 (43.85). It can be seen from this that the optimal conditions for the growth of mycelium of White Sac Rake Tooth Fungus are carbon source (maltose), nitrogen source (peptone), pH (4.5), and temperature (30℃).
[0076] Table 1 Visual analysis of the orthogonal test results of mycelial growth of white capsule rake tooth fungus
[0077]
[0078] 2.4 Screening of culture medium for bacterial expansion
[0079] White capsule rake tooth fungus can grow normally on all five culture media, but the mycelial growth rate on different media varies greatly. The mycelial growth rate on buckwheat medium is the fastest, significantly higher than other media, and the growth rate on wheat medium is the slowest. The order of mycelial growth rate from fastest to slow is buckwheat (16.44±0.40) > sorghum (14.78±0.42) > corn (12.65±0.23) > millet (12.47±0.33) > wheat (2.13±0.33) ( Figure 10 The mycelium of the white capsule rake tooth fungus grew best on buckwheat medium, followed by wheat medium and corn medium ( Figure 11 ). Comprehensive analysis showed that the most suitable culture medium for the propagation of Albizia serrata was buckwheat medium.
[0080] 2.5 Degradation of Caragana korshinskii by Pseudomonas aeruginosa nd6
[0081] 2.5.1 Effects of Albizia nd6 on the nutritional composition of Caragana korshinskii crumbs
[0082] Table 2 shows that most of the dry matter, crude protein, crude fat, crude ash, calcium, phosphorus, and soluble carbohydrates in the different treatment groups were significantly different from those in the control group (P < 0.05). The dry matter content of the original sample was significantly lower than that of the different treatments, while there were no significant differences in dry matter content between the different treatments. The order of dry matter content was, from highest to lowest, the high-temperature and high-pressure group > the pasteurized group > the original sample. The crude protein content in the original sample was significantly lower than that in the high-temperature and high-pressure group and the pasteurized group. The order of crude protein content was, from highest to lowest, the pasteurized group > the high-temperature and high-pressure group > the original sample. There were no significant differences in crude fat content between the original sample and the different treatments. The high-temperature group had a significantly lower crude fat content than the pasteurized group. The order of crude fat content was, from highest to lowest, the original sample > the pasteurized group > the high-temperature and high-pressure group. As for crude ash content, the original sample had a significantly lower content than the high-temperature and high-pressure group and the pasteurized group. The order of crude protein content was, from highest to lowest, the pasteurized group > the high-temperature and high-pressure group > the original sample.
[0083] The calcium content in the original sample group was significantly higher than that in the different treatment groups, with no significant differences among the treatments. The order from highest to lowest was original sample group > high temperature and high pressure group > pasteurized group. The phosphorus content in the original sample group was significantly lower than that in the different treatment groups, with no significant differences among the treatments. The order from highest to lowest was pasteurized group > high temperature and high pressure group > original sample group. The soluble carbohydrate content in the original sample group was significantly lower than that in the different treatment groups, with no significant differences among the treatments. The order from highest to lowest was high temperature and high pressure group > pasteurized group > original sample group.
[0084] Table 2 Effects of the fungus nd6 on the conventional nutritional components of fermented Caragana korshinskii feed (dry matter basis %)
[0085]
[0086]
[0087] 2.5.2 Degradation of lignocellulose in Caragana korshinskii by Leucospermum nd6
[0088] Table 3 shows that the neutral detergent fiber, acid detergent fiber, and acid detergent lignin contents of the different treatment groups were mostly significantly different from those of the control group (P < 0.05). The neutral detergent fiber content of the original group was significantly higher than that of the different treatment groups, with no significant differences between the different treatments. The order from highest to lowest was original group > HTHP group > pasteurized group. The neutral detergent fiber degradation rate of the pasteurized group was higher than that of the HTHP group in both treatments. The acid detergent fiber content of the original group was significantly higher than that of both the HTHP group and the pasteurized group. The order from highest to lowest was original group > HTHP group > pasteurized group. The detergent fiber degradation rate of the pasteurized group was higher than that of the HTHP group in both treatments. The acid detergent lignin content of the original group was significantly higher than that of the different treatment groups. The pasteurized group was significantly lower than that of the HTHP group in the pasteurized group. The order from highest to lowest was original group > HTHP group > pasteurized group. The acid detergent lignin degradation rate of the pasteurized group was higher than that of the HTHP group in the pasteurized group.
[0089] Table 3 Degradation of lignocellulose by Albizia nd6 (dry matter basis %)
[0090]
[0091] As can be seen, the present invention conducted a comprehensive analysis and evaluation of the biological characteristics of the white-sac rake tooth fungus isolated from dead branches of Caragana korshinskii. Single-factor experimental results showed that the fungus grew best when maltose was the carbon source, peptone was the nitrogen source, the pH was 5.5, and the culture temperature was 35°C. The optimal carbon source for the mycelium of white-sac rake tooth fungus nd6 was maltose. The optimal nitrogen source for the mycelium of white-sac rake tooth fungus nd6 was peptone. The optimal temperature for the mycelium of white-sac rake tooth fungus nd6 was 35°C, making it a thermophilic fungus. The optimal pH for the mycelium of white-sac rake tooth fungus nd6 was 5.5.
[0092] In an orthogonal experiment for the cultivation of mycelium of the white-sac spore nd6 strain, the interaction between various factors was considered. Based on the results of the variance analysis, it was suggested that the preferred temperature for culturing white-sac spore nd6 was 30°C; the selection of nitrogen and carbon sources was also considered; and finally, the pH of the culture medium was adjusted to 4.5. Screening of culture media for the propagation of white-sac spore nd6 revealed that buckwheat medium was the optimal medium. This differs from the corn medium used for propagation by Yu Ping (Yu Ping, Sui Feifei, Chen Yanqiu. ITS sequence identification and artificial cultivation of wild white-sac spore nd6 strains in Changbai Mountain). This suggests that the same strain may not require the same nutrients in different geographical locations, resulting in significant differences in culture conditions.
[0093] After 56 days of fermentation with the white sac nd6 fermentation system, the nutrient content of the crumbed caragana crumbs showed significant changes. Five indicators, including dry matter, crude protein, crude ash, soluble carbohydrates, and phosphorus, were significantly higher in the high-temperature and high-pressure (HTHP) and pasteurized fermentation systems than in the original fermentation system. However, crude fat and calcium, unlike other indicators, were either not significantly different or significantly lower in the HTHP and pasteurized fermentation systems compared to the original fermentation system. Neutral detergent fiber, acid detergent fiber, and acid detergent lignin contents were significantly lower in the HTHP and pasteurized fermentation systems than in the original fermentation system, with acid detergent lignin in the pasteurized fermentation system significantly lower than in the original fermentation system. The degradation rates of neutral detergent fiber, acid detergent fiber, and acid detergent lignin in the pasteurized fermentation system were higher in the HTHP group, reaching 8.10%, 10.46%, and 18.67%, respectively. This suggests that the white sac nd6 fermentation system can convert the otherwise inaccessible lignocellulose in caragana crus into nutrients that can be used by ruminants.
[0094] In summary, single-factor and orthogonal experiments revealed that the optimal formula for mycelial growth of the fungus Leucospermum nd6 is maltose as the carbon source, peptone as the nitrogen source, a temperature of 30°C, and a pH of 4.5. The optimal culture medium for propagation is 98% buckwheat, 1% glucose, and 1% gypsum. Fermentation of shredded Caragana korshinskii hay by Leucospermum nd6 using different fermentation methods increased the content of most nutrients, meeting the nutritional requirements of Caragana korshinskii feed. Furthermore, the pasteurized version significantly reduced the contents of neutral detergent fiber, acid detergent fiber, and acid detergent lignin compared to the original version. The conversion of Caragana korshinskii into feed is currently the primary method for effectively utilizing Caragana korshinskii waste in sandy areas. This invention addresses a major technical bottleneck in this process. Both high-temperature and high-pressure sterilization and pasteurization significantly degrade Caragana korshinskii wood fibers. The feed value of Caragana korshinskii stubble treated with these two methods is significantly higher than that of conventional shredded Caragana korshinskii hay, indicating that large-scale commercialization of Caragana korshinskii feed is imminent.
[0095] Example 2
[0096] Sixty six-week-old, eight-browed pigs weighing 8 ± 0.5 kg were randomly divided into two groups of 30 pigs each. Dry matter intake was calculated based on the feed intake and residual amount. Feed intake was adjusted daily to observe the pigs' feeding behavior. The experimental period lasted 42 days, including a one-week pre-feeding period and a six-week main trial period. Feed and water were freely available.
[0097] Pig feed was prepared according to the Pig Feeding Standard (NY / T 65-2004). The specific composition is shown in Table 4. During the pre-feeding period, all pigs were fed pig feed. After the pre-feeding period, the experimental group was fed pig feed supplemented with caragana fermented feed (wheat and corn DDGS were replaced with an equal amount of caragana fermented feed), while the control group continued to be fed pig feed.
[0098] Table 4 Pig feed ingredients
[0099] Raw material composition content corn 58.70 wheat 15.00 Corn DDGS 6.00 soybean meal 15.00 Shell powder 0.90 Sodium chloride 0.35 Calcium hydrogen phosphate 0.30 Calcium dihydrogen phosphate 0.30 L-Lysine 0.25 DL-methionine 0.20 Premix 3.00 total 100.00
[0100] The premix provides the following per kilogram of feed: VB115mg, VB230 mg, VB615mg, VK 35mg, VB120.5mg, niacin 170mg, pantothenic acid 50mg, biotin 2.5mg, folic acid 7.0mg, VA 8000IU, VD 1800IU, VE 50mg, Mn 30mg, Zn120mg, Fe 80mg, Cu 35mg, I 0.5mg, Se 0.4mg.
[0101] The preparation method of the fermented caragana feed is as follows: after sterilizing the caragana shredded debris at 80°C for 6 hours, adjusting the moisture content to 65%, inoculating white capsule fungus at an inoculum amount of 5%, and fermenting for 56 days to obtain the fermented caragana feed.
[0102] On the first day and the morning of the last day of the experiment, all the pigs were weighed on an empty stomach. The feed intake, average daily gain (ADG), average daily feed intake (ADFI) and feed-to-gain ratio (F / G) of each pen were recorded. The calculation formula is as follows:
[0103] Average daily weight gain (g / d) = (final weight - initial weight) / number of test days
[0104] Average daily feed intake (g / d) = total dry matter intake / number of experimental days
[0105] Feed-to-weight ratio = average daily feed intake / average daily weight gain
[0106] Table 5 Growth performance questionnaire
[0107]
[0108] It can be seen from the contents recorded in Table 5 that compared with the control group, the average daily weight gain of the eight-browed pigs in the experimental group was significantly increased, and the feed-to-weight ratio was significantly reduced, indicating that the fermented caragana feed provided by the present invention can significantly improve the growth rate and feed utilization rate of the eight-browed pigs.
[0109] After the experiment, three eight-browed pigs were randomly selected from the experimental group and the control group for fasting jugular vein blood collection. Serum samples were collected and stored at -20°C. The activities of superoxide dismutase (SOD), malondialdehyde (MDA), glutathione peroxidase (GSH-px), and catalase (CAT) in the serum of the eight-browed pigs were determined using a kit method. The average results are shown in Table 6.
[0110] Table 6 Oxidation Index Questionnaire
[0111]
[0112] It can be seen from the contents recorded in Table 3 that compared with the control group, the activities of superoxide dismutase, glutathione peroxidase and catalase in the serum of the eight-browed pigs in the experimental group were significantly increased, and the levels of lipid peroxidation products such as malondialdehyde were significantly reduced. This shows that the fermented caragana feed provided by the present invention can effectively enhance the antioxidant capacity of the body of the eight-browed pigs and can reduce oxidative stress damage.
[0113] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.
Claims
1. A strain of Irpex lacteus nd6, which was deposited in the General Microbiology Center of China Culture Collection Administration, located at No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, on March 10, 2025, with the deposit number CGMCC No. 41795.
2. A method for cultivating the white capsule rake tooth fungus nd6 according to claim 1, characterized in that: The steps include: (1) inoculating the white cyst nd6 into an activation medium for activation culture; (2) The activated white sac rake tooth fungus nd6 in step (1) is inoculated into a propagation medium for propagation culture.
3. The culture method according to claim 2, wherein The activation culture medium is prepared from the following components in mass concentrations: 18-22 g / L of peptone, 1.5-2.5 g / L of maltose, 1.5-2.5 g / L of potassium dihydrogen phosphate, 0.8-1.2 g / L of magnesium sulfate, and 18-22 g / L of agar powder; the conditions for the activation culture and the expansion culture are both 28-32° C. and pH 5.4-5.6; the expansion culture medium is prepared from the following components in mass parts: 97-99 parts of buckwheat, 0.5-1.5 parts of gypsum, and 0.5-1.5 parts of sugar; and the water content of the expansion culture medium is 63-67%.
4. Use of the white capsule rake tooth fungus nd6 according to claim 1 in decomposing Caragana korshinskii.
5. Use of the white capsule rake tooth fungus nd6 according to claim 1 in preparing caragana fermented feed.
6. A fermented feed of Caragana korshinskii, characterized in that: The preparation method of the fermented caragana feed is as follows: after the caragana shredded debris is sterilized, it is inoculated with the white capsule rake tooth fungus nd6 according to claim 1 for fermentation.
7. The feed according to claim 6, characterized in that The sterilization method is: sterilization at 78-82° C. for 5-7 hours; and the fermentation time is 50-60 days.
8. The feed according to claim 6, characterized in that The water content of the sterilized Caragana kneaded debris is 63-67%; the inoculation mass percentage concentration of the white capsule rake tooth fungus nd6 is 4-9%.
9. Use of the feed according to any one of claims 6 to 8 in preparing feed for pigs, cattle or sheep.
10. The use according to claim 9, characterized in that The pig feed is eight-browed pig feed; the cattle feed is Mongolian cattle feed; and the sheep feed is Hulunbuir sheep feed.