Aspergillus awamori capable of simultaneously producing feruloyl esterase, cellulase and xylanase at high yield and application of aspergillus awamori

Abstract

The invention relates to the technical field of microbial application and bioengineering, and discloses an aspergillus awamori SNJ-2F capable of simultaneously producing feruloyl esterase, cellulase and xylanase at high yield, which is separated from Shennongjia high-temperature yeast for making hard liquor and preserved in China Center for Type Culture Collection with the preservation number of CCTCC NO: M20252024. The invention also discloses a screening method of the strain, a bran seed preparation process and a method for producing ferulic acid by performing enzymolysis on starch-removed wheat bran with a bran seed crude enzyme. The strain disclosed by the invention is strong in enzyme system synergy, green in process and low in cost, can be used for ferulic acid preparation, white spirit / soy sauce brewing and feed industry, and has a wide application prospect.

Description

Technical Field

[0001] This invention relates to the fields of microbial application and bioengineering technology, specifically proposing a strain of Aspergillus buergerianus isolated from Shennongjia high-temperature koji that simultaneously produces high yields of ferulic acid esterase, cellulase and xylanase, as well as its screening method, bran seed preparation process, and the application of this strain and bran seed in ferulic acid enzymatic hydrolysis preparation, compound enzyme preparation production, and the brewing of baijiu, soy sauce, and feed industries. Background Technology

[0002] Ferulic acid, a natural phenolic acid with various physiological activities such as antioxidation, antibacterial, and anti-inflammatory properties, has extremely high application value in food additives, pharmaceutical intermediates, and cosmetic raw materials. It mainly cross-links with arabinoxylan and cellulose in plant cell walls via ester bonds and is widely found in agricultural byproducts such as wheat bran and rice bran. Currently, the traditional industrial method for obtaining ferulic acid is mainly chemical alkaline hydrolysis. This method requires strong acids and bases to control the reaction conditions, which not only easily leads to the destruction of the ferulic acid structure and low product purity but also generates a large amount of high-COD wastewater, seriously polluting the environment and failing to meet the industrial development requirements of green manufacturing.

[0003] To overcome the shortcomings of chemical methods, enzymatic hydrolysis has become a research hotspot due to its advantages of mild conditions and high specificity. However, plant cell walls have complex structures, and single ferulic acid esterases cannot effectively break through the cell wall barrier. It requires the synergistic destruction of cell wall polysaccharide structures by cellulase and xylanase to expose the ester bonds connecting ferulic acid and polysaccharides, thus achieving efficient release of ferulic acid. In existing technologies, enzymatic hydrolysis often employs a "single enzyme-producing strain fermentation + multiple enzyme preparations mixed" model. This not only suffers from a narrow enzyme production spectrum (most Aspergillus oryzae can only produce 1-2 target enzymes at high yields) and poor enzyme synergy, but also results in high production costs due to the need to purchase multiple enzyme preparations. Some schemes attempt to construct complex enzyme systems through multi-strain mixed fermentation, but nutrient competition between different strains easily leads to instability in the fermentation process, with enzyme activity fluctuations exceeding 30%, making it difficult to meet the needs of industrial production.

[0004] High-temperature koji (a type of starter culture) is a core auxiliary material in baijiu brewing. The high-temperature environment above 60℃ during its production enriches it with a large number of heat-resistant, high-enzyme-producing microorganisms, making it a natural resource pool of functional microorganisms. Among them, the microbial community structure in Shennongjia's high-temperature koji is more specific due to its unique geographical and ecological conditions, such as high altitude and large diurnal temperature range, containing untapped potential high-enzyme-producing strains. Although *Aspergillus awamori* is recognized as a safe enzyme-producing strain, current technology has not reported any *Aspergillus awamori* strains from Shennongjia high-temperature koji that simultaneously produce high levels of ferulic acid esterase, cellulase, and xylanase. Furthermore, there is a lack of targeted screening methods for this type of strain and suitable low-cost fermentation processes, resulting in the underutilization of the industrial value of high-temperature koji microbial resources. Summary of the Invention

[0005] In view of this, the present invention aims to overcome the shortcomings of the existing technology, such as low efficiency and high pollution in ferulic acid preparation, narrow enzyme spectrum of Aspergillus awamori, poor targeting of screening process, and high fermentation cost. It provides a solution for Aspergillus awamori that simultaneously produces three key enzymes, as well as its screening, preparation and application, so as to realize the green and efficient preparation of ferulic acid and cost reduction and efficiency improvement in related industrial fields.

[0006] The technical solution of this invention is achieved as follows: This invention provides a strain of *Aspergillus awamori* that simultaneously produces high levels of ferulic acid esterase, cellulase, and xylanase. This strain was isolated from Shennongjia high-temperature koji and deposited at the China Center for Type Culture Collection (CCTCC), located at No. 299 Bayi Road, Wuchang District, Wuhan University, Wuhan, Hubei Province, 430072, China, on September 15, 2025, with accession number CCTCCNO:M 20252024.

[0007] In some embodiments, the present invention also provides a method for screening Aspergillus foetida described above, the method comprising the following steps: a) Take a sample of Shennongjia high-temperature Daqu (a type of Chinese liquor), add sterile physiological saline containing 0.1% Tween 80, vortex, and prepare a serial dilution to 10. -3 -10 -7 Bacterial suspension; b) Spread 100 μL of bacterial suspension onto three selective culture media: medium 1 containing 0.1% ethyl ferulic acid, medium 2 containing 1% sodium carboxymethyl cellulose (CMC-Na), and medium 3 containing 1% xylan. The basic formulation of all media was PDA medium (potato 200 g / L, glucose 20 g / L, agar 15 g / L), and then add the corresponding substrates (0.1% ethyl ferulic acid, 1% CMC-Na, 1% xylan) and incubate at 28-32℃ for 48-72 hours. c) Select colonies that can produce hydrolysis zones on all three culture media, purify them by streak plating, inoculate them into wheat bran substrate, and ferment them in solid state at 28-32℃ and initial moisture content of 70%-90% for 60-84 hours. d) The crude enzyme solution of the fermentation product was extracted, and the strain was identified as Aspergillus buergerianus by ITS rDNA sequence sequencing, thus obtaining the target strain.

[0008] In some embodiments, in the Aspergillus buergerianum screening method provided by the present invention, the first culture medium in step b) is used to screen strains that produce ferulic acid esterase, and the activity of the strain is judged by observing whether a hydrolysis zone is formed around the colony; the second culture medium and the third culture medium are used to screen strains that produce cellulase and xylanase, respectively, and the transparent hydrolysis zone is observed by the Congo red staining method, and the ratio of the diameter of the hydrolysis zone to the diameter of the colony is used as the preliminary basis for judging enzyme activity.

[0009] In some embodiments, the present invention also provides a method for preparing bran starter using the above-described Aspergillus foetida, the method comprising: 1) Using wheat bran as the solid fermentation substrate, adjust the initial pH of the substrate to 4.0-6.0, control the substrate moisture content to 50%-80%, sterilize at 121℃ for 25-35 minutes, and then cool to room temperature; 2) Inoculate the treated substrate with a spore suspension of Aspergillus buergerianus at an inoculation rate of 5%-15% (v / w, spore suspension volume / dry wheat bran mass). 3) Cultivate at a constant temperature of 25-35℃ for 60-84 hours to obtain bran seed.

[0010] In some embodiments, the preferred process parameters for the above-mentioned bran seed preparation method are: initial pH of 4.5, substrate moisture content of 80%, and sterilization time of 30 minutes in step 1); inoculation amount of 10% (v / w) in step 2); and culture temperature of 30°C and culture time of 72 hours in step 3). Under these parameters, the crude enzyme solution of the bran seed prepared exhibits the optimal activity of the three enzymes. This parameter combination can balance the activities of the three enzymes. A pH below 4.0 inhibits xylanase activity, while a pH above 5.0 reduces the stability of ferulic acid esterase. An inoculation amount below 10% leads to a prolonged enzyme production cycle, while an inoculation amount above 10% triggers substrate nutrient competition. Therefore, a 10% inoculation amount is the efficiency-cost balance point. In some embodiments, the present invention also provides a method for enzymatically releasing ferulic acid using the above-mentioned bran seeds, the method comprising: A) taking bran seeds, mixing them with 10-15 mL of 100 mM acetate-sodium acetate buffer (pH 4.0-5.0) at a ratio of 1 g of bran seeds, extracting at 28-32°C for 0.5-1.5 hours, centrifuging at 3000-5000 rpm for 10-15 minutes, and filtering to obtain a crude enzyme solution; B) mixing the crude enzyme solution with plant material, adding the above-mentioned acetate-sodium acetate buffer to adjust the pH of the system to 4.0-5.0, enzymatically hydrolyzing at 32-38°C for 0.5-1.5 hours, centrifuging and filtering to obtain an enzymatic hydrolysate containing ferulic acid.

[0011] In some embodiments, in the above-mentioned enzymatic release of ferulic acid method, the plant material is preferably destarched wheat bran; the mass ratio of crude enzyme solution to destarched wheat bran is (4-6):1; the preferred conditions for the enzymatic hydrolysis process are a temperature of 35°C and a time of 1 hour; the preferred centrifugation parameters for the extraction process are a speed of 4000 rpm and a time of 12 minutes, under which the ferulic acid release can reach 44.97±1.26 mg / L.

[0012] In some embodiments, the Aspergillus oryzae provided by the present invention can be used to prepare a complex enzyme preparation for degrading plant cell walls. This complex enzyme preparation contains ferulic acid esterase, cellulase and xylanase, which can be used to destroy the polysaccharide structure of plant cell walls and is suitable for grain processing, biomass conversion and other fields.

[0013] In some embodiments, the *Aspergillus oryzae* provided by this invention can also be applied to the brewing of baijiu (Chinese liquor) or soy sauce. Through its complex enzyme system, it degrades cellulose and hemicellulose in raw materials, improving raw material utilization and promoting the release of flavor precursors, thereby improving product quality. Bran seed can be added to the koji-making raw materials at a ratio of 0.5%-1%, and its complex enzyme system degrades cellulose in the raw materials, improving saccharification efficiency and promoting the release of Maillard reaction precursors.

[0014] In some embodiments, the Aspergillus oryzae provided by this invention can also be applied to the feed industry. Its complex enzyme system can degrade anti-nutritional factors (such as non-starch polysaccharides) in feed, improving feed digestibility and reducing breeding costs. Wheat bran can be pulverized and added to compound feed at a ratio of 2%-3%. Its enzyme system can degrade non-starch polysaccharides in the feed, reducing intestinal digesta viscosity and improving nutrient absorption.

[0015] The present invention has the following advantages over the prior art: The present invention offers significant advantages. Compared to existing technologies, firstly, at the strain level, the *Aspergillus oryzae* isolated from the unique habitat of Shennongjia high-temperature Daqu (a type of fermented liquor) not only possesses superior natural heat tolerance but also achieves efficient production of ferulic acid esterase, cellulase, and xylanase simultaneously through a single strain. This effectively solves the problems of narrow enzyme spectrum and poor synergy in multi-strain mixed fermentation of conventional *Aspergillus oryzae*, providing a more efficient enzyme system foundation for subsequent enzymatic hydrolysis. Secondly, regarding the screening method, the three-level system of "simultaneous screening with three selective culture media + solid-state fermentation re-screening + molecular biological identification" is more targeted than traditional single-plate screening, accurately eliminating invalid strains and significantly improving the efficiency of obtaining target high-yield strains. Thirdly, in terms of the preparation process, inexpensive wheat bran is used... As a solid fermentation substrate, it not only meets the enzyme production needs of the strains but also serves as a substrate for subsequent enzymatic hydrolysis, forming a cyclical model of "using bran to cultivate bacteria and using enzymes to hydrolyze bran." This effectively reduces raw material costs and overcomes the limitations of high costs associated with multi-strain and multi-substrate solutions in existing technologies. Furthermore, the entire process does not rely on strong acids or alkalis, resulting in milder reaction conditions and completely avoiding the environmental pollution problems associated with traditional chemical methods for ferulic acid preparation, thus aligning better with green manufacturing principles. In addition, this strain and its related products can not only be used for the green preparation of ferulic acid but are also widely applicable to various fields such as liquor brewing, soy sauce brewing, and the feed industry. Compared to existing technologies, its application scenarios are broader, improving raw material utilization and product quality in various fields while reducing production energy consumption, demonstrating outstanding industrial practical value. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is the frontal colony morphology of Aspergillus SNJ-2F on a PDA plate according to the present invention; Figure 2 This is the reverse colony morphology of Aspergillus SNJ-2F on a PDA plate according to the present invention. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0019] Example 1: Screening and Identification of Strains (1) Take 10g of Shennongjia high-temperature Daqu sample, add it to 90mL of enrichment medium, vortex and shake to prepare a bacterial suspension of 10⁻¹, and further serially dilute to 10⁻⁷. The enrichment medium formula is: glucose 20g / L, peptone 10g / L, yeast extract 5g / L, NaCl 5g / L, pH 6.0, sterilize at 121℃ for 30min.

[0020] (2) Take 100 μL of bacterial suspensions with five dilution gradients from 10⁻³ to 10⁻⁷ and spread them on ethyl ferulic acid plates, sodium carboxymethyl cellulose plates and xylan plates respectively, and incubate them upside down in a 30℃ incubator for 72 h.

[0021] (3) Observe the growth of colonies on ethyl ferulic acid plates and the size of the clear zone around the colonies. Select strains with hydrolysis zones, isolate and purify them, and preserve them as slant culture. At the same time, inoculate the purified strains into ferulic acid esterase plates and culture for 3 days. Record the diameter of the hydrolysis zone and the size of the colony, and calculate the enzyme activity index. After staining CMC-Na and xylan plates with Congo red, wash repeatedly with distilled water until the liquid is colorless, and then decolorize with NaCl to observe the formation of the hydrolysis zone. Cellulase or xylanase produces hydrolysis zones around the strains. Select strains with obvious clear zones, isolate and purify them, and preserve them as slant culture. Inoculate the purified strains into cellulase isolation plates and xylanase isolation plates respectively and culture for 3 days. Record the diameter of the hydrolysis zone and the size of the colony, and calculate the enzyme activity index. Finally, select 12 colonies with clear hydrolysis zones and large enzyme activity indices on all three types of plates.

[0022] (4) The strains screened in the initial screening were subjected to solid-state fermentation of wheat bran for secondary screening. Fresh wheat bran was used as the enzyme-producing medium, with an initial moisture content of 80% (V / W). The medium was sterilized at 121℃ for 30 min, cooled to room temperature, and then inoculated with a 10% inoculum of Aspergillus buergerianus SNJ-2F spore suspension. The medium was then incubated at 30℃ for 72 h. After incubation, 5.00 g of wheat bran inoculum was accurately weighed and placed in a 250 mL Erlenmeyer flask. 60 mL of acetate-sodium acetate (pH 4.6, 100 mM) buffer was added, and the mixture was extracted at 30℃ for 1 h. The extract was then centrifuged and filtered to obtain the crude enzyme solution.

[0023] Assay for ferulic acid esterase catalytic activity: The activity of maltodextrin esterase using methyl ferulic acid (MFA) as a substrate was determined by preparing a 1 mM methyl ferulic acid (MFA) solution in an acetate-sodium acetate buffer solution (pH 4.6 100 mM).

[0024] Sample group: Take 1 mL of diluted crude enzyme solution to be tested, incubate in a 30°C water bath for 5 min, add 1 mL of MFA solution, react at 30°C for 10 min, then add 2 mL of 10% glacial acetic acid (V / V) to terminate the reaction, centrifuge and filter, and determine the ferulic acid content in the sample by high performance liquid chromatography.

[0025] Blank group: Before adding methyl ferulic acid, 2 mL of 10% glacial acetic acid was added to the enzyme solution to inactivate the enzyme. The remaining steps were the same as those for the sample group.

[0026] Enzyme activity is defined as the amount of enzyme required to hydrolyze methyl ferulic acid per minute to produce 1 µmol of ferulic acid at 30°C and pH 4.6.

[0027] Cellulase catalytic activity assay: A glucose standard curve was prepared before the experiment.

[0028] Standard blank sample: Take 2.0 mL of sodium acetate buffer solution, add 2.5 mL of DNS reagent, heat in boiling water for 5 min, cool to room temperature with tap water, and then make up to 10 mL to prepare the standard blank sample.

[0029] Experimental group: The sodium carboxymethyl cellulose solution and the crude enzyme solution to be tested were pre-equilibrated at 30℃ for 10 min. 0.5 mL of the crude enzyme solution to be tested was placed in a test tube, and 1.5 mL of 1% sodium carboxymethyl cellulose solution was added. The mixture was shaken and incubated at 30℃ for 5 min. After incubation, 2.5 mL of DNS reagent was added, and the mixture was shaken and incubated to terminate the reaction. The mixture was then heated in a boiling water bath for 5 min, cooled to room temperature with tap water, and diluted to a final volume of 10 mL. The absorbance was measured at 540 nm using a standard blank as a control.

[0030] Blank group: Pipette 0.5 mL of the crude enzyme solution to be tested into a colorimetric tube. First, add 2.5 mL of DNS reagent and shake to inactivate the enzyme. Then, add 1.5 mL of 1% sodium carboxymethyl cellulose solution. React at 30℃ for 5 min, followed by heating in a boiling water bath for 5 min. Cool to room temperature with tap water, add water to a final volume of 10 mL, shake to mix, and use the standard blank sample as a blank control. Measure the absorbance at 540 nm.

[0031] Enzyme activity is defined as the amount of enzyme required to degrade and release 1 μmol of glucose per minute from a sodium carboxymethyl cellulose solution at 30°C and pH 4.6. One unit of enzyme activity (U) is defined as the amount of enzyme required to do so.

[0032] Xylanase catalytic activity assay: Standard blank sample: Take 2.0 mL of sodium acetate buffer solution, add 2.5 mL of DNS reagent, heat in boiling water for 5 min, cool to room temperature with tap water, and then make up to 10 mL to prepare the standard blank sample.

[0033] Experimental group: The xylan solution and the crude enzyme solution to be tested were equilibrated at 30℃ for 10 min beforehand. 0.5 mL of the crude enzyme solution was added to a colorimetric tube, followed by 1.5 mL of 1% xylan solution. The mixture was shaken and incubated at 30℃ for 5 min. After the reaction, 2.5 mL of DNS reagent was added and shaken to terminate the enzymatic hydrolysis. The mixture was then heated in a boiling water bath for 5 min, cooled to room temperature with tap water, and diluted to 10 mL with water. The absorbance was measured at 540 nm using a standard blank as a control.

[0034] Control group: Pipette 0.5 mL of the crude enzyme solution to be tested into a colorimetric tube, add 2.5 mL of DNS reagent and shake to mix, then add 1.5 mL of 1% xylan solution, incubate at 30℃ for 5 min, and heat in a boiling water bath for 5 min. Cool to room temperature with tap water, add water to make up to 10 mL, shake to mix, and use the standard blank sample as a blank control. Measure the absorbance value at 540 nm.

[0035] Enzyme activity is defined as the amount of enzyme required to degrade and release 1 μmol of xylose per minute from a xylan solution at 30°C and pH 4.6.

[0036] Determination of ferulic acid content released from destarched wheat bran by crude enzyme solution: 0.1 g of destarched wheat bran was placed in a centrifuge tube, 4 mL of pH 4.6 acetate-sodium acetate buffer was added, and the mixture was incubated in a water bath at 35 °C for 5 min. Then, 1.0 mL of crude enzyme solution was added, and the mixture was enzymatically hydrolyzed at 35 °C for 1 h. The supernatant was collected by centrifugation, and the ferulic acid content was determined by HPLC.

[0037] The results showed that strain SNJ-2F had the highest activities of the three enzymes, with ferulic acid esterase activity of 831.38±62.97 mU / mL, cellulase activity of 189.81±6.61 U / mL, and xylanase activity of 589.37±56.61 U / mL. At this time, SNJ-2F released 24.71±1.48 mg / L of ferulic acid from destarched wheat bran.

[0038] (5) The ITS rDNA sequence of this strain was sequenced and compared in GenBank. The results showed that it had 99.99% homology with Aspergillus awamori. Based on its colony morphology and microscopic characteristics, the strain was identified as Aspergillus awamori.

[0039] Example 2: Optimization of bran seed preparation process Using ferulic acid release as the final determination index, the preparation process of Aspergillus buergerianus SNJ-2F bran seed was optimized by single-factor experiments.

[0040] A single-factor rotation method was used to investigate the effects of initial moisture content (50%, 60%, 70%, 80%, 90%, 100%), initial pH (4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0), inoculum size (5%, 10%, 15%, 20%), and culture temperature (25℃, 30℃, 35℃) on the release of ferulic acid from destarched wheat bran by crude enzyme solution of *Aspergillus buergerianus* SNJ-2F bran starter, based on the initial fermentation conditions. After culture, the crude enzyme solution was extracted from the bran starter, and the catalytic activities of the three enzymes and their effects on the release of ferulic acid from destarched wheat bran were determined.

[0041] The results showed that when the moisture content of the bran seed was 80%, the initial pH was 4.5, the inoculum size was 10%, and the culture temperature was 30℃, the catalytic activities of the three enzymes in Aspergillus SNJ-2F reached their strongest. At this time, the catalytic activities of ferulic acid esterase were 1070.36±83.67 mU / mL, cellulase was 331.18±27.04 U / mL, and xylanase was 880.80±67.18 U / mL. The amount of ferulic acid released from the destarched wheat bran was 44.97±1.26 mg / L, which was 81.99% higher than before optimization.

[0042] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A strain of Aspergillus awamori which simultaneously produces high levels of ferulic acid esterase, cellulase and xylanase, characterized in that, The Aspergillus awamori is isolated from Shennongjia high-temperature Daqu and preserved in China Center for Type Culture Collection with the preservation number of CCTCC NO: M 20252024.

2. The method of claim 1, wherein the screening of the A. awamori is characterized by, The method comprises the following steps: a) Take Shennongjia high-temperature Daqu samples, add sterile normal saline containing 0.1% Tween 80, vortex and shake, prepare gradient dilution to 10 -3 -10 -7 of bacterial suspension; b) 100 μL of the bacterial suspension is respectively coated on three kinds of selective culture media: the first culture medium containing 0.1% ethyl ferulate, the second culture medium containing 1% sodium carboxymethyl cellulose, and the third culture medium containing 1% xylan, and incubated at 28-32°C for 48-72 hours; c) the colonies capable of producing hydrolysis rings on the first culture medium, the second culture medium and the third culture medium are selected, inoculated into wheat bran medium after streak purification, and subjected to solid-state fermentation at 28-32°C with an initial moisture content of 70%-90% for 60-84 hours; d) the crude enzyme solution of the fermentation product of step c) is extracted, and the corresponding strain is identified by ITS rDNA sequence determination to be Aspergillus awamori, i.e. the Aspergillus awamori of claim 1 is obtained.

3. A method for preparing bran seeds using the A. awamori of claim 1, characterized by, The method comprises the following steps: 1) taking wheat bran as the solid fermentation substrate, adjusting the initial pH of the substrate to 4.0-6.0, controlling the moisture content of the substrate to be 50%-80%, sterilizing the substrate at 121°C for 25-35 minutes, and then cooling the substrate to room temperature; 2) inoculating the spore suspension of the Aspergillus awamori of claim 1 into the substrate treated in step 1) at an inoculation amount of 5%-15% (v / w, volume of spore suspension / mass of dry wheat bran); 3) incubating the substrate at 25-35°C for 60-84 hours to obtain bran seeds.

4. The method of claim 3, wherein, In step 1), the initial pH is 4.5, the moisture content of the substrate is 80%, and the sterilization time is 30 minutes; in step 2), the inoculation amount is 10% (v / w); in step 3), the incubation temperature is 30°C, and the incubation time is 72 hours.

5. A bran seed, characterized by The bran seeds are prepared by the method of claim 3 or 4.

6. A method for the release of ferulic acid by enzymatic hydrolysis of bran according to claim 5, characterized in that, The method comprises the following steps: A) taking the bran seeds of claim 5, mixing 1 g of bran seeds with 10-15 mL of pH 4.0-5.0 acetic acid-sodium acetate buffer at a ratio, extracting at 28-32°C for 0.5-1.5 hours, centrifuging at 3000-5000 rpm for 10-15 minutes, and then filtering to obtain a crude enzyme solution; B) mixing the crude enzyme solution with plant material, adjusting the pH of the system to 4.0-5.0 by adding the acetic acid-sodium acetate buffer, and enzymatically hydrolyzing at 32-38°C for 0.5-1.5 hours to obtain an enzymatic hydrolysate containing ferulic acid.

7. The method of claim 6, wherein, In step B), the plant material is de-starched wheat bran; the mass ratio of the crude enzyme solution to the de-starched wheat bran is (4-6):1; the enzymatic hydrolysis temperature is 35°C, and the enzymatic hydrolysis time is 1 hour; in step A), the centrifugation speed is 4000 rpm, and the centrifugation time is 12 minutes.

8. Use of the Aspergillus awamori of claim 1 in the preparation of a complex enzyme preparation for degrading plant cell walls.

9. Use of the Aspergillus awamori of claim 1 in the brewing of liquor or soy sauce.

10. Use of the Aspergillus awamori of claim 1 in the feed industry.

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