Fertilizer prepared from selenium-rich mushroom bran compost and preparation method thereof

Abstract

The invention discloses a fertilizer prepared from selenium-rich mushroom bran compost and a preparation method thereof, and relates to the field of agricultural fertilizers, in particular to the fertilizer prepared from the selenium-rich mushroom bran and the preparation method thereof. The method for preparing the fertilizer from the selenium-rich mushroom bran compost comprises the following steps: 1, crushing the selenium-rich mushroom bran, adjusting the water content, and then composting and carrying out aerobic fermentation; and 2, inoculating a bacillus licheniformis (Bacillus licheniformis) J-048 bacterial solution into the compost obtained in the step 1, and then continuing to carry out aerobic fermentation. According to the method, two-stage aerobic fermentation is adopted, aerobic fermentation is still adopted in the second stage, but aerobic low-temperature fermentation is adopted. According to the method disclosed by the invention, a metabolic pathway of bacillus licheniformis J-048 is changed by utilizing a selenium-rich environment through second-stage aerobic fermentation, so that the bacillus licheniformis J-048 generates organic selenium.

Description

Technical Field

[0001] The present invention relates to the field of agricultural fertilizers, and in particular to a fertilizer prepared from selenium-enriched mushroom husks and a preparation method thereof. Background Art

[0002] Selenium (Se) is an essential trace element for the human body, playing an irreplaceable role in enhancing antioxidant capacity, fighting cancer, protecting the liver, and preventing and treating cardiovascular disease. A moderate amount of selenium in the diet is beneficial for maintaining human health. Selenium deficiency is a major cause of Kashin-Beck disease and Keshan disease. The recommended daily selenium intake for adults is 50 to 200 μg / day, with a maximum intake of no more than 400 μg / day. However, inorganic selenium cannot be directly absorbed and utilized by the human body; it must be metabolized by plants, where it is converted naturally occurring into organic selenium. Therefore, consuming fruits, vegetables, and grains containing organic selenium is an important source of selenium intake for humans. However, over 70% of my country's territory is selenium-deficient, including densely populated areas such as Northeast China, North China, coastal areas, and Sichuan. Fruits, vegetables, and grains in these areas are not enriched with organic selenium, resulting in the public's intake of this beneficial trace element falling short of the recommended value.

[0003] Organic selenium is highly beneficial for human absorption and supplementation. This includes plant-derived, animal-derived, fungal (yeast-derived), and mushroom-derived selenium. Plants and animals have low tolerance to selenium and other elements, resulting in relatively low selenium content. However, mushrooms have hundreds to thousands of times greater capacity for selenium absorption, accumulation, and conversion than plants and animals. For example, selenium-enriched mushrooms can contain over 200 mg of selenium per kilogram, while selenium-enriched eggs contain only 0.20 mg per kilogram, a 1,000-fold difference. Mushrooms contain high-quality, high-content protein and lack phytic acid, making them a relatively superior choice for selenium and other element enrichment. my country has developed large-scale cultivation of selenium-enriched edible fungi, generating significant amounts of selenium-rich fungus waste. However, significant amounts of selenium in this waste remain unutilized. Utilizing selenium-enriched fungus waste to develop crop by-products for animal feed and organic fertilizer is a promising approach to developing a circular economy and will significantly contribute to addressing selenium deficiencies in fruits, vegetables, and grains.

[0004] However, current technologies for using selenium-rich fungus waste as fertilizer still use mostly inorganic selenium, which is toxic to humans and has certain negative impacts on the environment, land, animals, and plants, leading to its use being banned in some developed countries. While yeast has a higher tolerance for selenium than plants and animals, it is not suitable for composting fungus waste. Furthermore, yeast selenium has poor solubility, resulting in low plant utilization as a fertilizer. Summary of the Invention

[0005] In order to more effectively utilize selenium-rich mushroom bran and convert the selenium in the selenium-rich mushroom bran into harmless organic selenium that can be efficiently utilized by plants, the present invention provides a fertilizer prepared from selenium-rich mushroom bran compost and a preparation method thereof.

[0006] A method for preparing fertilizer from selenium-rich fungus husk compost:

[0007] 1. Crush the selenium-rich fungus husks, adjust the moisture content, and then aerobically ferment the compost to 60-65°C. Maintain the compost at 60-65°C and continue aerobic fermentation for 20-30 days.

[0008] 2. Inoculating the compost from step 1 with a Bacillus licheniformis J-048 bacterial solution and continuing aerobic fermentation for 30 to 40 days to obtain a fertilizer prepared from the selenium-enriched compost;

[0009] In step 2, the aerobic fermentation temperature is controlled not to exceed 45°C.

[0010] Furthermore, the inoculation amount of Bacillus licheniformis J-048 bacterial solution is 1-2% of the weight of the selenium-enriched bacterial bran.

[0011] Furthermore, the concentration of Bacillus licheniformis J-048 in the Bacillus licheniformis J-048 bacterial solution is 1×10 9 ~5×10 9 cfu / ml.

[0012] Furthermore, after the aerobic fermentation in step 2 is completed, citric acid powder is added to the compost and mixed evenly; the amount of citric acid added is 0.1% to 0.3% of the weight of the selenium-enriched fungus bran.

[0013] The fertilizer prepared from selenium-rich mushroom husk compost of the present invention is a fertilizer prepared according to one of the above methods.

[0014] Furthermore, a fertilizer is provided, which includes the above-mentioned fertilizer prepared from selenium-rich mushroom husk compost.

[0015] The fertilizer prepared by the invention can be mixed with other raw material components to prepare agricultural organic fertilizer and light matrix.

[0016] The method of the present invention adopts a two-stage aerobic fermentation, wherein the second stage still adopts aerobic fermentation but is a low-temperature aerobic fermentation. The method of the present invention utilizes a selenium-rich environment in the second stage aerobic fermentation to change the metabolic pathway of Bacillus licheniformis J-048, thereby producing organic selenium.

[0017] Bacillus licheniformis J-048 was deposited in the General Microbiology Center of China Culture Collection Administration (CGMCC), the deposit address is No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, the deposit date is July 7, 2014, and the deposit number is CGMCC No. 9419. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present invention are clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0019] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0020] Specific embodiment 1: This embodiment provides a method for preparing fertilizer from selenium-rich fungus husk compost:

[0021] 1. Crush the selenium-rich fungus husks, adjust the moisture content, and then aerobically ferment the compost to 60-65°C. Maintain the compost at 60-65°C and continue aerobic fermentation for 20-30 days.

[0022] 2. Inoculating the compost from step 1 with a Bacillus licheniformis J-048 bacterial solution and continuing aerobic fermentation for 30 to 40 days to obtain a fertilizer prepared from the selenium-enriched compost;

[0023] In step 2, the aerobic fermentation temperature is controlled not to exceed 45°C.

[0024] Specific embodiment 2: This embodiment differs from specific embodiment 1 in that the inoculation amount of Bacillus licheniformis J-048 bacterial solution is 1-2% of the weight of selenium-enriched bacterial bran. Other steps and parameters are the same as those of specific embodiment 1.

[0025] Specific embodiment 3: The difference between this embodiment and specific embodiment 1 or 2 is that the concentration of Bacillus licheniformis J-048 in the bacterial solution is 1×10 9 ~5×10 9 cfu / ml. Other steps and parameters are the same as those in the first or second embodiment.

[0026] Specific embodiment 4: This embodiment differs from specific embodiments 1, 2, or 3 in that: after the aerobic fermentation is completed in step 2, citric acid powder is added to the compost and mixed evenly; the amount of citric acid added is 0.1% to 0.3% by weight of the selenium-enriched fungus husk. The other steps and parameters are the same as those of specific embodiments 1, 2, or 3.

[0027] Example 1

[0028] Method for preparing fertilizer from selenium-rich fungus husk compost:

[0029] 1. Crush the selenium-rich oyster mushroom husks and adjust the moisture content to 50%-60%. Then, heat the compost to 60-65°C for aerobic fermentation and maintain the compost at 60-65°C for 22 days.

[0030] 2. Inoculating the compost from step 1 with a Bacillus licheniformis J-048 bacterial solution and continuing aerobic fermentation for 33 days to obtain a fertilizer prepared from the selenium-enriched compost;

[0031] The temperature of the aerobic fermentation in step 2 is controlled not to exceed 45° C. The inoculation amount of the Bacillus licheniformis J-048 bacterial solution is 1.2% of the weight of the selenium-enriched bacterial husk; the concentration of Bacillus licheniformis J-048 in the Bacillus licheniformis J-048 bacterial solution is 1×10 9 ~3×10 9 cfu / ml.

[0032] Example 2

[0033] Method for preparing fertilizer from selenium-rich fungus husk compost:

[0034] 1. Crush the selenium-rich oyster mushroom husks and adjust the moisture content to 50%-60%. Then, heat the compost to 60-65°C for aerobic fermentation and maintain the compost at 60-65°C for 27 days.

[0035] 2. Inoculating the compost from step 1 with a Bacillus licheniformis J-048 bacterial solution and continuing aerobic fermentation for 36 days to obtain a fertilizer prepared from the selenium-enriched compost;

[0036] The temperature of the aerobic fermentation in step 2 is controlled not to exceed 45° C. The inoculation amount of the Bacillus licheniformis J-048 bacterial solution is 1.5% of the weight of the selenium-enriched bacterial husk; the concentration of Bacillus licheniformis J-048 in the Bacillus licheniformis J-048 bacterial solution is 2×10 9 ~4×10 9 cfu / ml.

[0037] Example 3

[0038] Method for preparing fertilizer from selenium-rich fungus husk compost:

[0039] 1. Crush the selenium-rich oyster mushroom husks and adjust the moisture content to 50%-60%. Then, heat the compost to 60-65°C for aerobic fermentation and maintain the compost at 60-65°C for 23 days.

[0040] 2. Inoculating the compost from step 1 with a Bacillus licheniformis J-048 bacterial solution and continuing aerobic fermentation for 34 days; after fermentation, adding citric acid powder to the compost and mixing evenly; the amount of citric acid added is 0.2% by weight of the selenium-enriched bacterial residue; thus, obtaining a fertilizer prepared from the selenium-enriched bacterial residue compost;

[0041] The temperature of the aerobic fermentation in step 2 is controlled not to exceed 45° C. The inoculation amount of the Bacillus licheniformis J-048 bacterial solution is 1.5% of the weight of the selenium-enriched bacterial husk; the concentration of Bacillus licheniformis J-048 in the Bacillus licheniformis J-048 bacterial solution is 2×10 9 ~4×10 9 cfu / ml.

[0042] Example 4

[0043] The selenium in the sample is completely decomposed into a measurable form (generally Se(IV) or Se(VI)) by acid digestion or microwave digestion, and then the selenium content in the fertilizers prepared in Examples 1 to 3 is determined by an appropriate analytical method (such as hydride atomic fluorescence spectrometry or ICP-MS). The test data are shown in Table 1.

[0044] Inorganic selenium (Se(IV) and Se(VI)) in the fertilizers prepared in Examples 1-3 is separated from organic selenium using a specific adsorption material (such as an ion exchange resin or a chelating resin). The inorganic selenium is then separated by changing the pH or adding a specific eluent. Se(VI) in the sample is then reduced to Se(IV) using a chemical reducing agent (such as hydroxylamine hydrochloride or hydrochloric acid-stannous chloride). The concentration of Se(IV) is then measured using hydride atomic fluorescence spectrometry or ICP-MS to determine the inorganic selenium content in the fertilizer.

[0045] Organic selenium = total selenium - inorganic selenium.

[0046] 0.1 kg of each of the fertilizers prepared in Examples 1 to 3 was enzymatically hydrolyzed by adding 0.3% wt of cellulase for 2 h. After enzymatic hydrolysis, the enzyme was inactivated at 86-90° C. and the mixture was centrifuged at 400 rpm for 15 min. The supernatant was collected and the soluble selenium (IV) in the sample was converted into volatile hydrogen selenide (H2Se). The fluorescence intensity was then measured by atomic fluorescence spectrometry, and the soluble selenium content was calculated. The test data are shown in Table 1.

[0047] Table 1

[0048] Total selenium content Organic selenium content Inorganic selenium content Soluble selenium content Example 1 28.2 mg / kg 22.1 / kg 6.1 / kg 21.7 / kg Example 2 30.7 mg / kg 23.6 / kg 7.1 / kg 23.3 / kg Example 3 27.9 mg / kg 22.3 / kg 5.6 / kg 22.5 / kg

[0049] According to the test data in Table 1, it can be seen that the method of the present invention can effectively convert inorganic selenium in selenium-rich Pleurotus ostreatus mushroom waste into a large amount of organic selenium; and the organic selenium has excellent solubility.

[0050] Example 5

[0051] The fertilizers prepared in Examples 1 to 3 and the fertilizers prepared in Control Groups 1 and 2 were applied at a rate of 20 to 25 kg per mu, once during the heading and flowering period of the rice. The selenium content of rice in the different groups of plots after harvest is shown in Table 2.

[0052] Among them, the fertilizer preparation method of control group 1 is as follows: the selenium-rich oyster mushroom chaff is crushed, the moisture content is adjusted to 50% to 60%, and then the compost is aerobic fermented and heated to 60 to 65°C, and the compost is maintained at 60 to 65°C for further aerobic fermentation for 23 days; thus, the preparation of the fertilizer is completed.

[0053] Preparation method of fertilizer for control group 2: 1. Crush the selenium-rich oyster mushroom husks and adjust the moisture content to 50%-60%, then aerobically ferment the compost to 60-65°C and maintain the compost at 60-65°C for 23 days;

[0054] 2. Turn the compost and continue aerobic fermentation for 34 days; after the fermentation is completed, add citric acid powder to the compost and mix evenly; the amount of citric acid added is 0.2% of the weight of the selenium-rich fungus husk; thus, the preparation of the fertilizer is completed.

[0055] Table 2

[0056] Example 1 Example 2 Example 3 Control group 1 Control group 2 Selenium content in rice 95 μg / kg 98 μg / kg 97 μg / kg 34 μg / kg 38 μg / kg

[0057] The method of the present invention can effectively convert inorganic selenium in selenium-rich oyster mushroom husks into a large amount of organic selenium, greatly improving the absorption and utilization of selenium by crops.

Claims

1. A method for preparing fertilizer from selenium-rich fungus husk compost, characterized in that The method proceeds as follows:

1. Crush the selenium-rich fungus husks, adjust the moisture content, and then aerobically ferment the compost to 60-65°C. Maintain the compost at 60-65°C and continue aerobic fermentation for 20-30 days.

2. Inoculating the compost from step 1 with a Bacillus licheniformis J-048 bacterial solution and continuing aerobic fermentation for 30 to 40 days to obtain a fertilizer prepared from the selenium-enriched compost; In step 2, the aerobic fermentation temperature is controlled not to exceed 45°C.

2. The method for preparing fertilizer from selenium-rich fungus husk compost according to claim 1, wherein The inoculation amount of Bacillus licheniformis J-048 bacterial solution is 1-2% of the weight of selenium-enriched bacterial bran.

3. The method for preparing fertilizer by composting selenium-rich fungus husks according to claim 1 or 2, wherein The concentration of Bacillus licheniformis J-048 in the bacterial solution was 1×10 9 ~5×10 9 cfu / ml.

4. The method for preparing fertilizer by composting selenium-rich fungus husks according to claim 3, wherein Step 2: After the aerobic fermentation is completed, citric acid powder is added to the compost and mixed evenly; the amount of citric acid added is 0.1% to 0.3% of the weight of the selenium-enriched fungus husk.

5. A fertilizer prepared from selenium-rich fungus husk compost, characterized in that: A fertilizer prepared according to any one of claims 1 to 4.

6. A fertilizer, characterized in that The fertilizer comprises the fertilizer prepared from selenium-rich mushroom residue compost according to claim 5.