In-situ fermentation method for oxygen-induced directional arrangement of bacterial cellulose fibers

Abstract

The invention belongs to the field of microbial fermentation engineering, and discloses an oxygen-induced bacterial cellulose fiber oriented arrangement in-situ fermentation method, which comprises the following steps: injecting a culture solution into a fermentation container with a length space, uniformly distributing the culture solution along the length direction of the fermentation container, sterilizing and cooling; and then inoculating the pre-cultured aerobic strains into the culture medium, controlling oxygen concentration difference generated in the fermentation container along the length direction, carrying out fermentation culture, and carrying out drying treatment to obtain the bacterial cellulose membrane. According to the method disclosed by the invention, by virtue of the fermentation container and the aerobic strains, the bacteria move from an area with reduced oxygen concentration to an area with high oxygen concentration, secreted bacterial cellulose chains are arranged along a movement track during movement of the bacteria, and generated fibers are directionally arranged, so that in-situ preparation of the large-size fiber ordered arrangement bacterial cellulose is realized.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of microbial fermentation engineering, and more particularly relates to an in-situ fermentation method for directional arrangement of oxygen-induced bacterial cellulose fibers. BACKGROUND

[0002] Bacterial cellulose, as a kind of biological macromolecular polymer, is a kind of natural nanocellulose produced by fermentation of some microorganisms (such as Komagataeibacter xylinus), which has unique physical, chemical and biological properties, such as high purity, high crystallinity, high mechanical strength, degradability, controllable modification and good biocompatibility, and is widely used in biomedical, food, cosmetics, material science and other fields.

[0003] In the conventional fermentation method, the motion trajectory of the bacteria is irregular, so the microstructure of the bacterial cellulose obtained presents a random network structure. Such structure is not conducive to fully exerting the mechanical properties of the new type of material bacterial cellulose. And existing research shows that the ordered fiber arrangement has a great influence on the mechanical strength of the material. Compared with the material with irregular fiber arrangement, the mechanical strength of the material can be greatly improved when the fibers are arranged in order.

[0004] In the prior art, in order to exert the potential of bacterial cellulose and improve its mechanical strength, researchers use electrospinning, wet spinning, wet stretching, dynamic culture, and limiting the motion direction of bacteria to control the fiber orientation of cellulose, so as to improve the mechanical strength of the cellulose material. However, dynamic culture will disturb the culture medium during the culture process, on the one hand, such culture method has low production efficiency, on the other hand, the thickness of the bacterial cellulose obtained is uneven, and even the phenomenon of bacterial cellulose aggregation may occur, so that the bacterial cellulose with ordered fiber arrangement cannot be stably and effectively obtained, thereby the mechanical properties cannot be improved to the expected effect. Therefore, it is necessary to develop a way that can realize large-scale fermentation, and realize the regulation of the fiber orientation of bacterial cellulose during the in-situ fermentation process, so as to improve the mechanical strength of bacterial cellulose. SUMMARY

[0005] In view of the above defects or improvement needs of the prior art, the present application provides an in-situ fermentation method for directional arrangement of oxygen-induced bacterial cellulose fibers, which aims to affect the oxygen concentration difference during the fermentation culture process, so that the oxygen concentration in the device is high during the growth process of the aerobic bacteria, and the bacterial cellulose chains secreted during the movement of the bacteria are arranged along the movement trajectory, so that the produced fibers are arranged in a certain direction, and large-size ordered arrangement of bacterial cellulose is realized in-situ, thereby solving the problem that it is difficult to stably and effectively prepare uniformly arranged bacterial cellulose in the prior art.

[0006] In order to achieve the above-mentioned purpose, in the first aspect of the present application, an in-situ fermentation method for oxygen-induced directional arrangement of bacterial cellulose fibers is provided, comprising: injecting a culture solution into a fermentation container with a length space and uniformly distributing along the length direction of the fermentation container; then inoculating pre-cultured aerobic bacterial strains into the culture medium, controlling the oxygen concentration difference along the length direction in the fermentation container to perform fermentation culture, and drying to obtain a bacterial cellulose membrane.

[0007] Preferably, the aerobic bacterial strains include Acetobacter xylinum, Acetobacter aceti, Acetobacter aceti or Acetobacter pasteurianus; preferably Acetobacter xylinum.

[0008] Preferably, the inoculation of pre-cultured aerobic bacterial strains into the culture medium is followed by static culture, and then the oxygen concentration difference along the length direction in the fermentation container is controlled to perform fermentation culture; wherein the conditions of the static culture are: static culture at 20-35℃ for 2-7 days.

[0009] Preferably, the control of the oxygen concentration difference along the length direction in the fermentation container comprises: controlling the oxygen exchange at one end of the fermentation container along the length direction and stopping the oxygen exchange at the other end; or, keeping one end of the fermentation container along the length direction in an open state and the other end in a closed state.

[0010] Preferably, one end of the fermentation container along the length direction is kept in an open state and the other end is kept in a closed state alternately, and the interval time of the alternation is 6-48h.

[0011] Preferably, after the inoculation of pre-cultured aerobic bacterial strains into the culture medium, inert gas is first filled into the fermentation container, and then the oxygen concentration difference along the length direction in the fermentation container is controlled.

[0012] Preferably, the sterilization comprises high-temperature sterilization or ultraviolet sterilization; the sterilization temperature of the high-temperature sterilization is 115-121℃, and the sterilization time is 15-20min.

[0013] Preferably, the purification after the culture is performed by an alkali treatment method, specifically: using 0.1-1mol / L NaOH solution to boil the cultured material for 1-2h, and then soaking and changing water multiple times with deionized water until the water after soaking is neutral.

[0014] Preferably, the drying treatment comprises hot-press drying or natural drying. When the drying treatment is hot-press drying, the pressure of the hot-pressing is 1-5MPa, the hot-pressing temperature is 60-100℃, and the hot-pressing time is 2-48h.

[0015] Preferably, the fermentation container has a length of 500-2000 mm, an inner diameter of 10-200 mm, and a ratio of length to inner diameter of (10-20):1, the inner diameter being a diameter or its equivalent diameter.

[0016] Overall, compared with the prior art, the above technical solutions conceived by the present application mainly have the following technical advantages: 1. The method for preparing the directionally arranged bacterial cellulose provided by the present application can realize the static and in-situ preparation of large-size fiber-ordered bacterial cellulose by affecting the oxygen concentration difference in the fermentation culture process, so that the bacterial cellulose chains secreted by the aerobic bacteria species moving to the area with high oxygen concentration in the device during the growth process are arranged along the moving track in the bacterial movement, the generated fibers are directionally arranged, and the bacterial cellulose with fiber order and uniform thickness can be obtained more stably in a stable and controllable environment, thereby effectively improving the mechanical properties of the bacterial cellulose.

[0017] 2. The aerobic bacteria species pre-cultured in the present application are inoculated into the culture medium, and then static culture is performed, and then the oxygen concentration of the air vents at both ends of the fermentation container is controlled. The static culture makes the bacteria reproduce first to obtain a high-concentration bacterial population, so that the high-concentration bacterial population quickly consumes oxygen during the subsequent oxygen regulation process, quickly forms an oxygen concentration difference, and quickly enters the oxygen induction link, thereby improving the generation efficiency of the directionally arranged bacterial cellulose.

[0018] 3. The present application preferably controls the oxygen concentration of the air vents at both ends of the fermentation container, including: exchanging oxygen through one end of the air vents at both ends of the fermentation container, and stopping oxygen exchange through the other end; or, keeping one end of the air vents at both ends of the fermentation container open and the other end closed, and realizing manual or automatic adjustment through the two ways.

[0019] 4. The present application preferably alternately keeps one end of the air vents at both ends of the fermentation container open and the other end closed, so that the oxygen concentration difference between the two ends of the device is alternated during the fermentation process, which can induce the bacteria to move from one end of the device to the other end, and then move in the opposite direction when the oxygen concentration difference is alternated. The back-and-forth movement of the bacteria makes the finally obtained bacterial cellulose membrane more uniform and the mechanical strength more obviously improved.

[0020] 5、The present application preferably inoculates the pre-cultured aerobic bacterial species into the culture medium, first fills the inert gas into the fermentation container, and then controls the oxygen concentration of the air inlet at both ends of the fermentation container, wherein the inert gas is filled to exclude the air (oxygen) in the device as much as possible, and the oxygen concentration difference is generated rapidly after the bacteria are introduced, which avoids the random fiber network structure generated by the disordered movement of bacteria during the fermentation time without forming the oxygen concentration difference, so that the overall fiber arrangement degree of bacterial cellulose is better.

[0021] In summary, the method of the present application realizes the preparation of fiber directional arrangement cellulose in situ by using oxygen to induce the directional movement of aerobic bacterial species in the presence of concentration difference. At the same time, the present application can realize the preparation of large size unidirectional arrangement bacterial cellulose in situ, expand its application range, and the orientation degree of bacterial cellulose fiber is better than that of traditional bacterial cellulose, and the tensile strength can be improved from 200-300 MPa to more than 600 MPa compared with traditional bacterial cellulose. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is the front view of the fermentation container used in the comparative example and the examples of the present application, wherein: 1 is the main body of the fermentation container, 2 is the air inlet, and 3 is the hose.

[0023] Figure 2 is the surface FESEM image of the bacterial cellulose prepared in the comparative example 1 and examples 1-3 of the present application, wherein Figure 1 a corresponds to the comparative example, b corresponds to example 2, c corresponds to example 1, and d corresponds to example 3.

[0024] Figure 3 is the mechanical property test diagram of the bacterial cellulose prepared in the comparative example and examples 1-3 of the present application. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application, and are not used to limit the present application. In addition, the technical features involved in each embodiment of the present application described below can be combined with each other as long as they do not conflict with each other.

[0026] To achieve the above object, the present application provides an in-situ fermentation method for directional arrangement of oxygen-induced bacterial cellulose fibers, which is based on a fermentation container and comprises the following steps: injecting a culture solution into the fermentation container with a length space, uniformly distributing along the length direction, and then sterilizing and cooling; inoculating pre-cultured aerobic bacterial strains into the culture medium, controlling the oxygen concentration difference along the length direction in the fermentation container, and performing in-situ fermentation culture; and drying to obtain a bacterial cellulose membrane.

[0027] In the present application, the fermentation container with a length space is a container with a certain length space in the internal culture area, but not limited to the shape, for example, including square tube, round tube, serpentine tube, etc.

[0028] In some embodiments, the aerobic bacterial strains of the present application include Acetobacter xylinum, Acetobacter aceti, Acetobacter aceti or Acetobacter pasteurianus; preferably Acetobacter xylinum. Any one of Hestrin-Schramm (HS) medium (glucose, peptone, yeast extract, Na2HPO4, citric acid), Yamanaka (Yamanaka) medium (fructose, peptone, yeast extract, K2HPO4, MgSO4·7H2O), and HS improved medium (glucose, peptone, yeast extract, Na2HPO4, citric acid) (preferably HS improved medium) can be used. In some embodiments, the pre-cultured aerobic bacterial strains of the present application are inoculated into the culture medium, and then static culture is performed, and then the oxygen concentration difference along the length direction in the fermentation container is controlled for fermentation culture. The static culture conditions are: static culture at 20-35°C for 2-7 days. A part of the bacterial cellulose membrane generated during the static culture period is reserved, so that the subsequent fiber-ordered cellulose membrane continues to stack on the reserved bacterial cellulose membrane, and the other part of the bacterial cellulose membrane shakes off to the bottom of the device, so that the bacteria generate fiber-ordered bacterial cellulose membrane on the liquid surface of the culture medium again. Preferably, the generated bacterial cellulose membrane in the device after static culture at 30°C for 2 days is shaken off to the bottom of the device, which can avoid the decrease of the overall mechanical properties of the bacterial cellulose membrane caused by the original fiber-disordered bacterial cellulose.

[0029] In some embodiments, the present application controls the oxygen concentration difference along the length direction in the fermentation container, which includes but is not limited to two examples of the present application. The two examples of the present application include: controlling the oxygen exchange at one end of the fermentation container along the length direction, and stopping the oxygen exchange at the other end, wherein the specific way of oxygen exchange can be manual or automatic operation; or, keeping one end of the fermentation container along the length direction as open and the other end as closed, and combining the oxygen consumption of the aerobic bacterial strains to generate the oxygen concentration difference in the length direction of the air inlet.

[0030] In this embodiment, to achieve the reciprocating movement of bacteria in the container, the oxygen concentration difference in the device is alternately changed by alternately keeping one end of the fermentation container in the length direction open and the other end closed. The alternately interval time is 6-48h.

[0031] In some embodiments, the prepared bacterial cellulose membrane is subjected to purification treatment to obtain a wet cellulose membrane. The purification treatment is an alkali treatment method, which is boiled in 0.1-1 mol / L, preferably 0.1 mol / L NaOH solution for 1-2h, preferably 1h, and then washed and soaked with deionized water until the soaked water is neutral. Then, the bacterial cellulose dry membrane is obtained through drying treatment.

[0032] In some embodiments, the drying treatment includes natural drying or hot-pressing drying treatment. The bacterial cellulose wet membrane prepared in step S3 is subjected to hot-pressing to obtain a bacterial cellulose dry membrane with ordered arrangement of fiber orientation. The hot-pressing treatment can increase the density of the bacterial cellulose membrane, thereby further improving the mechanical strength of the bacterial cellulose membrane. The pressure of hot-pressing is 1-5MPa, preferably 1MPa; the hot-pressing temperature is 60-100℃, preferably 80℃; and the hot-pressing time is 12-48h, preferably 48h. The bacterial cellulose dry membrane is obtained.

[0033] In some embodiments, the fermentation container has a length space and air vents at both ends in the length direction. The length of the fermentation container is 500-2000mm, the inner diameter is 10-200mm, and the ratio of length to inner diameter is (10-20):1. The inner diameter is the diameter or its equivalent diameter. For example, as shown in the oxygen induction fermentation device, different sizes of circular thin-walled silica gel soft or square silica gel soft tubes are used as the main body 1 of the fermentation container, and a hollow tube 3 is connected to each end of the square tube as an air vent 2, and a high-temperature-resistant tissue culture sealing film is covered at the air vent. Figure 1

[0034] The technical solutions in the present application are further described below in combination with the drawings and embodiments.

[0035] The fermentation container used in the following comparative examples and embodiments is a square silica gel tube with a length of 1000mm, a cross section of 40mm×40mm, and a wall thickness of 2mm. The opening and closing of the air vent are controlled by a switch and a sealing bag.

[0036] Comparative Example 1: ​S1, configure HS improved medium (glucose 20 g / L, peptone 5 g / L, yeast extract 5 g / L, Na2HPO46.8 g / L, citric acid 1.5 g / L), the prepared culture medium is transferred to an oxygen induction culture device (a square silica gel tube with a length of 1000 mm, a cross section of 40 mm*40 mm and a wall thickness of 2 mm), then the device with the culture solution is placed in an autoclave for sterilization, the sterilization temperature is 121℃, and the sterilization time is 20 minutes.

[0037] S2, the fermentation device in step S1 is taken out, and when the temperature decreases to about 30℃, the Acetobacter xylinum seed solution is introduced, and the device is placed in a constant temperature incubator, meanwhile, a sealing bag is sleeved on each end air inlet and is in an open state. Then static culture at 30℃ for 2 days, after 2 days of culture, the bacterial cellulose membrane formed on the surface is shaken and settled at the bottom of the device, and then static culture for 7 days to obtain the bacterial cellulose membrane.

[0038] S3, the bacterial cellulose membrane in step S2 is taken out and washed with deionized water, then boiled with 0.1 mol / L NaOH solution for 1 h, washed and soaked with deionized water after cooling, and the soaked deionized water is repeatedly replaced until the water after soaking is neutral, to obtain the purified bacterial cellulose wet membrane. Then the wet membrane is hot-pressed at 1 MPa and 80℃ for 48 h to obtain the bacterial cellulose dry membrane.

[0039] Example 1: The difference between this embodiment and example 1 is that in step S2, after 2 days of culture and shaking and settling the bacterial cellulose membrane formed on the surface to the bottom of the device, the sealing bag at one end is closed, and the other end is kept open.

[0040] Example 2: The difference between this embodiment and example 1 is that in step S2, after 2 days of culture and shaking and settling the bacterial cellulose membrane formed on the surface to the bottom of the device, the sealing bag at one end is closed, and the other end is kept open.

[0041] Example 3: The difference between this embodiment and example 2 is that in step S2, after 2 days of culture and shaking and settling the bacterial cellulose membrane formed on the surface to the bottom of the device, the sealing bag at one end is closed, and the other end is kept open.

[0042] Meanwhile, in the present application, the time interval of the opening and closing state change of the two-end sealed bag is set to 24 h based on Example 2 and Example 3. Meanwhile, the microstructure and mechanical properties of the bacterial cellulose obtained under this condition are tested, and the test results show that the degree of fiber orientation of the bacterial cellulose obtained under the condition of an interval of 24 h is greatly improved compared with the bacterial cellulose in the comparative example, and the effect is basically the same as that of the bacterial cellulose with an interval of 12 h; the mechanical strength is higher than that of Example 1 and Example 2, and is close to that of Example 3, which is 603.19 MPa.

[0043] The bacterial cellulose prepared in the above comparative examples and examples is tested and characterized, and the specific results are as follows.

[0044] Oxygen concentration difference test: The oxygen concentration of the air outlet of the device in the above comparative examples and examples is tested. The oxygen concentration inside the two ends of the device provided with the air outlet is tested by a gas detector. The time nodes for testing are as follows: after the bacterial cellulose film formed on the surface is shaken and settled at the bottom of the device in step S2 in the above specific examples, the opening and closing state of the two air outlets is controlled, and then the oxygen concentration of the two ends of the device is tested after 12 h of cultivation. The results show that when both ends of the air outlet are opened, the oxygen concentration of the two ends of the device has no difference and is consistent with the environmental oxygen concentration, which accounts for 20.9%; when one end is opened and the other end is closed, the oxygen concentration of the opened end is consistent with the environmental oxygen concentration, which is 20.9%, and the oxygen concentration of the closed end of the air outlet decreases obviously, which is 19.5% after 12 h of air outlet closure, and the oxygen concentration after 12 h of air outlet closure is 17.6%.

[0045] Morphological characterization of oxygen-induced directional arrangement of bacterial cellulose fiber film: The dry bacterial cellulose film obtained in the above comparative examples and examples is sprayed with gold, and the dry bacterial cellulose film is characterized by field emission scanning electron microscopy (FESEM). As shown in Figure 2 a, b, c, d, obviously, the fiber structure of the bacterial cellulose obtained in the experiment in which both ends of the air outlet are opened simultaneously is as shown in Figure 2 a of FIG. 8, which is a disordered network structure, because when both ends of the air outlet are opened simultaneously, both ends can exchange oxygen with the outside world, and there is no oxygen concentration difference, so the network structure of the bacterial cellulose is still disordered; in Example 1, one end of the air outlet is opened and the other end is closed, which causes the closed end of the air outlet to be unable to obtain oxygen from the outside world, and the oxygen concentration decreases after the original oxygen is consumed by bacterial metabolism, resulting in an oxygen concentration difference between the two ends, and the fiber structure of the obtained bacterial cellulose film is as shown in Figure 2 b of FIG. 8, which changes obviously, and the fiber orientation changes from a disordered network structure to an orderly arranged unidirectional arrangement structure; the network structure of the bacterial cellulose film obtained in Example 2 is as shown in Figure 2As shown in Fig. 2c, the bacteria are oriented more uniformly, but the degree of fiber orientation is not as high as that of Example 1 because the alternate time interval is short. The network structure of the bacterial cellulose film obtained in Example 3 is shown in Fig. 2d. Figure 1 As shown in Fig. 2c, the bacteria are oriented more uniformly, but the degree of fiber orientation is not as high as that of Example 1 because the alternate time interval is short. The network structure of the bacterial cellulose film obtained in Example 3 is shown in Fig. 2d.

[0046] Mechanical property test of the bacterial cellulose film with oxygen-induced oriented arrangement of bacterial cellulose fibers: The bacterial cellulose films in the above-mentioned examples and comparative examples were subjected to a mechanical property test, and the results are shown in Fig. 3. Figure 3 As shown in Fig. 3, in Comparative Example 1, the tensile strength of the bacterial cellulose obtained without forming an oxygen concentration difference was 256.78 MPa as shown by curve a in Fig. 3; in Example 1, after controlling the concentration difference between the two ends by opening the air inlet at one end and closing the other end, the tensile strength of the bacterial cellulose film was 564.44 MPa as shown by curve c in Fig. 3; in Example 2, while controlling the oxygen concentration difference in the device, the air inlets on both sides were alternately opened every 6 h, so that the oxygen concentration in the device changed alternately, and the tensile strength of the obtained bacterial cellulose was 427.27 MPa as shown by curve b in Fig. 3; in Example 3, while controlling the oxygen concentration difference in the device, the air inlets on both sides were alternately opened every 12 h, so that the oxygen concentration in the device changed alternately, and the tensile strength of the obtained bacterial cellulose was 607.17 MPa as shown by curve d in Fig. 3. Figure 3 Figure 3 Figure 3 Figure 3

[0047] In summary, the present application can prepare a larger size of bacterial cellulose with unidirectional arrangement of fibers under in-situ conditions, expand the application range, and the degree of fiber orientation of the bacterial cellulose is superior to that of conventional bacterial cellulose, and the tensile strength can be increased from 200-300 MPa to more than 600 MPa, which has a significant advantage.

[0048] Obviously, various modifications and changes can be made to the present application by those skilled in the art without departing from the spirit and scope of the present application. Thus, it is intended that the present application cover the modifications and changes as long as they come within the scope of the appended claims and their equivalents. The above examples are only preferred examples for fully illustrating the present application, and the scope of protection is not limited thereto. Any equivalent replacement or transformation made by those skilled in the art based on the present application is within the scope of protection of the present application.​​​​

Claims

1. A method for in-situ fermentation of oxygen-induced directional alignment of bacterial cellulose fibers, characterized in that, include: The culture medium is injected into a fermentation vessel with a length space and evenly distributed along the length of the fermentation vessel; then, pre-cultured aerobic bacteria are inoculated into the culture medium, and an oxygen concentration difference is generated along the length of the fermentation vessel for fermentation culture. After drying, a bacterial cellulose membrane is obtained.

2. The in-situ fermentation method for oxygen-induced directional alignment of bacterial cellulose fibers according to claim 1, characterized in that, The aerobic bacteria include Acetobacter xylinum, Acetobacter acetobacter, Acetobacter acetic acid, or Acetobacter pasteurellum; Acetobacter xylinum is preferred.

3. The in-situ fermentation method for oxygen-induced directional alignment of bacterial cellulose fibers according to claim 1, characterized in that, The pre-cultured aerobic bacteria are inoculated into the culture medium and statically cultured first. Then, the oxygen concentration difference along the length of the fermentation vessel is controlled to carry out fermentation culture. The static culture conditions are: static culture at 20-35℃ for 2-7 days.

4. The in-situ fermentation method for oxygen-induced directional alignment of bacterial cellulose fibers according to claim 1, characterized in that, Controlling the oxygen concentration difference along the length of the fermentation vessel includes: By controlling oxygen exchange at one end of the fermentation vessel along its length and stopping oxygen exchange at the other end; Alternatively, the fermentation container may be kept in an open state at one end along its length and in a closed state at the other end.

5. The in-situ fermentation method for oxygen-induced directional alignment of bacterial cellulose fibers according to claim 1, characterized in that, The fermentation container is alternately kept in an open state at one end along its length and in a closed state at the other end, with the alternation interval being 6-48 hours.

6. The in-situ fermentation method for oxygen-induced directional alignment of bacterial cellulose fibers according to claim 1, characterized in that, After inoculating the pre-cultured aerobic bacteria into the culture medium, the fermentation vessel is first filled with inert gas, and then the oxygen concentration difference is controlled to be generated along the length of the fermentation vessel.

7. The in-situ fermentation method for oxygen-induced directional alignment of bacterial cellulose fibers according to claim 1, characterized in that, The sterilization includes high-temperature sterilization or ultraviolet sterilization; the high-temperature sterilization temperature is 115-121℃, and the sterilization time is 15-20 minutes.

8. The in-situ fermentation method for oxygen-induced directional alignment of bacterial cellulose fibers according to claim 1, characterized in that, The cultured material is purified by alkaline treatment, specifically by boiling the fermented material in 0.1-1 mol / L NaOH solution for 1-2 hours, followed by repeated soaking and water changing with deionized water until the soaked water is neutral.

9. The in-situ fermentation method for oxygen-induced directional alignment of bacterial cellulose fibers according to claim 1, characterized in that, The drying process includes hot-press drying or natural drying; When the drying process is hot-press drying, the hot-press pressure is 1-5 MPa, the hot-press temperature is 60-100℃, and the hot-press time is 24-48 h.

10. The in-situ fermentation method for oxygen-induced directional alignment of bacterial cellulose fibers according to claim 1, characterized in that, The fermentation container has a length of 500-2000 mm and an inner diameter of 10-200 mm, with a length-to-inner diameter ratio of (10-20):

1. The inner diameter is the diameter or its equivalent diameter.

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