CN201241154Y - White-rot fungi solid fermentation system - Google Patents

Abstract

The utility model proposes a white rot fungus solid fermentation system, which includes a control system, a fermentation reactor, a heating system, a humidifier and an oxygen pump, etc.; the center of the fermentation reactor is uniformly surrounded by circulating water insulation pipes, and the circulation water insulation pipes and The heating system separately set outside the fermentation reactor is connected to form a heating circuit; the humidifier and the oxygen pump are respectively connected to the fermentation reactor through the steam pipe and the oxygen pipe, and the steam pipe is also uniformly arranged around the center of the fermentation reactor; A water filtering device is installed at the bottom of the reactor, and a temperature probe is installed inside; the control system has a control panel for displaying and setting temperature and humidity. The system is simple in structure and easy to operate. It can automatically control the temperature, humidity, and ventilation of white rot fungi fermentation, and can realize automatic control of the fermentation process, which is beneficial to the high production of lignin degrading enzymes by white rot fungi, improves the uniformity of fermentation, and shortens the fermentation cycle. Improve productivity.

Description

White rot solid fermentation system

technical field

The utility model relates to a fermentation device, in particular to an automatic reaction device for white rot fungus solid fermentation. The device can be used in the fields of environmental protection, biological pulping, food brewing and the like.

Background technique

The unique and effective degradation ability of white rot fungi makes it a powerful new force in the field of environmental protection. It transforms the active potential of this kind of filamentous fungi with spectrum attack on xenobiotics into media of different states in the environment. Realistic control of pollutants in the environment is the common pursuit goal and unremitting direction of efforts of scientists and related industries in various countries. Although compared with the mature bacterial system, the application of white rot fungi in environmental protection is still in the stage of exploration and establishment; although due to the particularity of the physiological metabolism of this type of bacteria and the almost harsh requirements for environmental factors, it has become a However, all of this has not stopped people from using various researches, developments and attempts of solid fermentation of white rot fungi in environmental protection practices.

The initial and largest practice of applying white rot fungus solid fermentation to pollution treatment is in the field of biopulping and water pollution control. Biopulping uses the ability of microorganisms to decompose lignin to remove wood from pulping raw materials. Pulping is the process of separating plant tissue and fibers from each other to make pulp. Generally, biological pretreatment is carried out on plant fiber raw materials before chemical treatment or mechanical refining. At present, biological pulping has entered the stage of industrialization and achieved good results.

Biopulping technology is an efficient and clean pulping process. Using white rot fungus solid fermentation to degrade lignin to remove lignin can alleviate the environmental pollution problem of paper industry. White rot fungi are the most effective type of microorganisms that degrade lignin in nature. They can produce active enzymes that degrade lignin or denatured lignin, lignin peroxidase (LiP), manganese peroxidase (MnP) and phenol The oxidase (laccase, Laccase) system constitutes the main active enzyme system for the degradation of lignin by white rot fungi. This characteristic of white rot fungi has been used in research fields such as biopulping and biobleaching, and some have entered the pilot test stage, showing its good application prospects.

In the literature <<The influence of morphology in the fermentation production of filamentous fungi and the design of fermenter>> (Biotechnology-2003 Issue 1), it is mentioned that the design of the fermenter specially for filamentous fungi cannot be achieved by promoting the formation of bacterial balls. To overcome all the problems caused by the viscous fermentation liquid of fungi, and for some fungi, the formation of bacteria balls is not conducive to the production of fermentation products. A simple method is to dilute the fermented liquid, but diluting the fermented liquid can only temporarily relieve the viscous problem of the fermented liquid Only by designing a special fermentation system can we fundamentally solve the difficulties caused by the viscosity of the fermentation broth during the fermentation process and a series of other problems.

At present, most mechanically stirred fermenters are equipped with radial flow turbine impellers, but recent studies have shown that axial flow impellers have advantages in many aspects of fungal fermentation. The cold model experiment with water and CMC as the medium shows that the mixing performance of the medium, the mass transfer effect and the power consumption of the axial flow impeller are significantly improved compared with the radial flow impeller. In the microbial fermentation experiment It is found that the axial flow stirring paddle is more suitable for high-density and high-viscosity microbial fermentation and stirring. High-density cultivation can finally increase the bacterial concentration by 12%, and the product content by 10%. High-viscosity fermentation can increase the production intensity by 20%. %. However, some studies have shown that in fermenters equipped with turbo paddles and axial flow paddles, as long as the given volume and mass transfer coefficients are consistent, there is no significant difference in the production of fungal metabolites. The airfoil paddle with axial flow has the advantages of mild shear performance, high conveying efficiency, rapid mixing, low energy consumption and high mass transfer coefficient, and has been successfully used in the production of industrial fermentation tanks such as gibberellin and Jinggangmycin. Another design is to install two different stirring paddles in the fermenter. Two different stirring paddles are installed on two separate drive rods and can rotate at different speeds. Each paddle plays a different role. A high-speed impeller can be installed at the bottom of the fermenter, which is mainly used to break up air bubbles and transmit a large amount of oxygen, and a slow axial flow stirring impeller can be installed on it to make the fermentation liquid flow to the impeller at the bottom. The combined use of the two paddles can improve the mixing of the fermentation broth. The research on the fermentation of chryseopenicillin production shows that the combination of axial flow impeller and turbine impeller instead of the traditional multi-layer impeller can strengthen the mixing and oxygen supply, and can ensure a suitable shear environment by adjusting the diameter of the impeller and the stirring speed (Penicillin fermentation requires a strong shearing environment). The study of alternative mixing systems for filamentous fungal fermentation is on the one hand to improve the mixing of large volumes of liquids, and on the other hand, the high shear force of the turbine blade (especially when rotating at high speed) will break the microbial hyphae, affecting the shape of the bacteria, Growth and metabolic activity are detrimental to the production of some fermentation products. If the stirring rate is increased, the deformation and damage of the mycelia due to the shear force will lead to a sharp decline in the itaconic acid production of Aspergillus terreus (ATerreus). It must be pointed out that the increase of stirring rate will lead to the increase of oxygen transmission rate and the increase of dissolved oxygen, and dissolved oxygen will sometimes reduce the production of metabolites of fungi, such as the production of extracellular polysaccharides by Apullulans, which is to dissolve Oxygen rather than shear force makes the yield decrease; in addition, in different periods of fermentation, the sensitivity of the bacteria to shear force is different, and the vacuolization will make the mycelia easy to break. In addition to the physical damage to the hyphae, the shear force generated by high stirring speed will also cause physiological inhibition to it, but there are not many studies in this area. Roukas studied the fermentative production of citric acid by Aspergillus niger Aniger at different stirring speeds, and detected several key enzymes in the TCA cycle. The results showed that the activities of aconitase and isocitrate dehydrogenase increased with the increase of stirring speed. increased, while the activity of citrate synthase decreased, which is undesirable for citrate accumulation. The high shear force of the radial flow turbine impeller can lead to the inhibition of the formation of some filamentous fungal fermentation products, but the shear force of the axial flow airfoil impeller may not be lower than that of the turbine impeller. Studies have reported that the same impeller diameter tank diameter Under normal circumstances, the axial flow impeller (considered as a low shear force system) caused more mycelium damage than the turbine impeller, but the axial flow impeller can make the large volume of fermentation liquid be better mixed, thereby improving Distribution of nutrients and supply of dissolved oxygen. The fed-batch fermentation research of Aoryzae on a production scale by Li et al. showed that the increase of impeller power had little effect on biomass, cell morphology and fission.

At present, there are also relevant patent literature reports on various fermentation devices. For example, the Chinese patent literature with publication number CN1958779 discloses "a solid-state fermentation device", which is a solid-state fermentation device suitable for large-scale fermentation of various microorganisms. It includes a main frame, and one or more fermentation units are set in the main frame; the fermentation unit is composed of a ventilation plate and a material fermentation bag arranged between the ventilation plates. The device has a simple structure and is easy to manufacture. It effectively overcomes the defects of uneven material temperature distribution, easy infection of bacteria, and poor mass and heat transfer in large-capacity solid-state fermentation reactors. However, this device can only solve microbial solid fermentation that does not require high water content, and there is no sterilization equipment, so it still lacks some necessary accessory equipment from the perspective of the application of the device.

The Chinese patent document with the publication number CN1786159 also discloses "a deep-layer solid fermentation method and device for producing laccase by fungal fermentation". The grass biomass raw materials sterilized by steam are mixed evenly, and put into the fermentation tank for fermentation. During the fermentation process, intermittent exhaust-oxygen cycle ventilation operation is performed. After fermentation, the materials are taken out and the enzyme liquid is squeezed out. Its device includes fermenter, vacuum pump, oxygen bottle, steam generator, control system, fermenter is a constant temperature tank, its upper part is connected with vacuum pump, its lower part is respectively connected with oxygen bottle and steam generator, and the control system is connected with fermenter, vacuum pump, oxygen Bottles are connected separately. This technology adopts intermittent exhaust-oxygen cycle ventilation operation, which improves the gas exchange efficiency and the ability of microorganisms to produce enzymes, and solves the problem of bacterial contamination. The equipment is simple and can be automatically controlled to increase the unit volume of the fermenter. The loading capacity of fermentation raw materials can achieve high yield and high efficiency of fungal fermentation to produce laccase. However, this technology is aimed at the submerged solid fermentation applied to the production of laccase by fungal fermentation. The research on the process conditions for the efficient degradation of lignin by solid fermentation of white rot fungi is not considered comprehensive enough. There are some defects in the inoculation method of white rot fungi. It should be selected to connect in the fermenter to reduce pollution, and the sterilization problem of the fermenter itself has not been solved.

In addition, the Chinese patent literature with the publication number CN2784419 discloses a "solid fermentation tank", which includes a tank body, and the tank body is provided with an inoculation port, a feed port, an exhaust port, a sampling port, a temperature measurement port, an inlet Gas port, discharge port, the outer circumference of the tank body is distributed with an outer jacket, the outer jacket is provided with an inlet and an outlet, the tank body is sleeved on the rotating shaft, and the rotating shaft is sleeved with a screw in the tank cavity. The rotating shaft is connected to the reducer through a coupling, and the reducer is connected to the motor through a belt. The seal at one end is connected to the universal pipe, and the seal divides the shaft chamber into a left chamber and a right chamber. The input end of the universal pipe passes through the seal and then extends into the left chamber, and the output end of the universal pipe is connected to the right chamber. The left cavity is respectively connected with the spiral inlet of the spiral blade, and the spiral outlet of the spiral blade is respectively connected with the right cavity. When the fermenter sterilizes the materials in the tank, the materials in the tank will not stick together, and the temperature and humidity in the tank are easy to control, and the fermentation period of the materials is short. Solid fermenter. However, the scope of application of the device is not clearly described, such as how to automatically control the temperature during low-temperature microbial solid fermentation, the pollution caused by the sterilization of oxygen is not considered when passing oxygen, and there is also a lack of observation window, which is not conducive to Observe the timely situation of microbial growth.

Although there are many applied researches on white rot fungi in pulping and papermaking, and they have shown very good results, there are still many problems in practical application. First of all, because the growth and reproduction of white rot fungi on the surface of wood chips or pulp and the enzyme secretion are affected by the pH value of the substrate, redox potential, nutritional requirements of the bacteria, temperature and humidity, etc., the activity of the lignin-degrading enzymes produced by white rot fungi is relatively low. Secondly, the cultivation process of white rot fungi to produce lignin-degrading enzymes is a culture process with a very high oxygen consumption rate, while the current fermentation industry is realized by deep ventilation culture, which requires a high stirring speed, which is harmful to the production of white rot fungi. The enzyme is very unfavorable, which makes it difficult to expand the cultivation of white rot fungi, which cannot meet the needs of the actual biopulping process; finally, the degradation of lignin by white rot fungi is accompanied by the degradation of cellulose, which will affect the strength properties of paper. In short, the biggest difficulty in the biopulping process of white rot fungi is that it is difficult to quickly and massively ferment lignin-degrading enzymes. None of the existing fermentation devices can effectively solve this problem. The main problem faced.

Utility model content

The purpose of this utility model is to address the shortcomings of the above technologies, and propose a solid fermentation system for white rot fungi, which can efficiently degrade lignin, and has a simpler structure, more practicality, and a larger capacity.

The technical scheme of the utility model is as follows:

A white-rot fungus solid fermentation system includes a control system, a fermentation reactor, and a heating system connected to the fermentation reactor, a humidifier, an oxygen pump, and the like. The center of the fermentation reactor is evenly arranged with circulating water insulation pipes, and the insulation pipes are connected to the heat supply system separately provided outside the fermentation reactor to form a heat supply circuit so that the required temperature can be maintained uniformly in the reactor. The humidifier and the oxygen pump are respectively connected to the fermentation reactor through a steam pipe and an oxygen pipe to maintain the required humidity and oxygen in the reactor, and the steam pipe is also uniformly arranged around the center of the fermentation reactor to make the humidity uniform. . The inner bottom of the fermentation reactor is provided with a water filtering device, so that cleaning is convenient after fermentation, and the sewage can flow out directly. There is a sampling port and an air outlet on the fermentation reactor. During the test, samples need to be taken in time. The diameter of the sampling port is 10 cm, which can be opened and closed automatically. Sampling from here can ensure that the fermentation material is not contaminated with bacteria, and the air outlet is specially designed for white rot. Bacteria, an aerobic fungus, is designed to facilitate the smooth flow of oxygen and ensure better growth of white rot fungi. A temperature probe is installed in the fermentation reactor to reflect the temperature in the reactor at any time for control. The heating system, humidifier, oxygen pump, and temperature probe are all connected to the control system through control lines or signal lines. The control system has a control panel for displaying and setting temperature and humidity, which can control the temperature, humidity, and oxygen supply of fermentation. and other process conditions to set and control.

The heating system is an electric hot water container, which is connected to the circulating water insulation pipe in the fermentation reactor through a circulation pipeline; the water intake of the electric hot water container is controlled by a submersible pump, and both the electric hot water container and the submersible pump are connected to the control system through a control line.

The fermentation reactor is a structure of a fermenter or a fermentation tank, and a layer of sponge insulation cover is wrapped around the fermentation reactor, and a discharge hole is arranged at the bottom of the fermenter or tank body, which can be opened and closed automatically.

The temperature probe and the humidity probe are inserted into the fermentation reactor through the sampling port or the gas outlet, or are set in the observation window, and a sterilizing filter membrane is set in the oxygen pump. The automatic control panel is equipped with internal circulating water heating indicator light, temperature setting knob, real-time temperature display window, main power switch, heating system and submersible pump working status indicator light and heating system, submersible pump power switch.

Advantages of this device

(1) The system is simple in structure and easy to operate. It can automatically control the temperature, humidity, and ventilation of white rot fungi fermentation, and can realize automatic control of the fermentation process, which is beneficial to the high production of lignin degrading enzymes by white rot fungi, improves the uniformity of fermentation, and shortens the time of fermentation. The fermentation cycle is shortened, and the productivity is improved. By enlarging the fermentation device and expanding the fermentation capacity, it can be directly applied to the pretreatment of the papermaking industry.

(2) The observation window on the fermentation reactor can clearly observe the growth of white rot fungi, which is convenient for timely adjustment of parameters such as temperature, humidity, and ventilation.

(3) Separate the heating system from the fermentation reactor, which can better control the temperature required for the test, and there is a layer of insulation cover outside the fermentation reactor to ensure a more stable temperature, and evenly arrange circulating water insulation pipes in the reactor, It can ensure that the entire fermentation process is evenly heated, and it can also make the poured materials loose and even.

(4) The water filter installed at the bottom of the fermentation reactor can filter out the water dripping from the lid when the steam is ventilated, and also play the role of ventilation to make the oxygen supply more uniform and sufficient.

(5) There is a discharge port at the bottom of the system, which can be opened and closed automatically. When processing fermentation materials, it can be discharged from here, and water for washing can also be discharged, which is convenient for thorough cleaning. The sterilizing filter membrane used in the oxygen pump can pass in sterile air, reduce the contamination rate of bacteria, and improve the quality of the product.

Description of drawings

Fig. 1 is the structural representation of this system;

Fig. 2 is a schematic diagram of the structure of the control panel;

Fig. 3 is the structural representation of fermentation tank;

Fig. 4 is the schematic diagram of fermenter lid;

Fig. 5 is the control schematic diagram of this system;

In Fig. 1, 1 fermentation automatic control system (including the setting of the temperature in the fermentation tank, the actual temperature display in the fermentation tank, the working instruction of the heating bucket, etc.), 2 electric hot water container, 3 submersible pump, 4 circulating water outlet pipe, 5 Circulating water inlet pipe, 6 temperature probe line, 7 power cord, 8 power socket, 9 fermenter tank, 10 steam pipe, 11 ultrasonic humidifier, 12 oxygen pipe, 13 oxygen pump, 14 fermenter support.

In Fig. 2, 1-1 preset temperature gauge in the fermenter, 1-2 real-time temperature display table in the fermenter, 1-3 total power on button, 1-4 lock, 1-5 total power off button, 1-6 Main power switch indicator light, 1-7 electric water tank and submersible pump power switch, 1-8 electric water tank and submersible pump power switch light.

In Fig. 3, 9-1 fermenter cover, 9-2 hygrometer, 9-3 automatic control valve, 9-4 perforated pipe for oxygen ventilation, 9-5 circulating water insulation pipe, 9-6 discharge hole, 9-7 has a porous water filter, and 9-8 drain valve.

Among Fig. 4, 9-9 observation window, 9-10 air outlet, 9-11 temperature probe jack, 9-12 sampling hole.

Detailed ways

Referring to Fig. 1, the white rot fungus solid fermentation system is mainly composed of a fermentation automatic control system 1, a fermentation tank 9, an electric hot water container 2 connected to the fermentation tank, an ultrasonic humidifier 11, an oxygen pump 13, and a circulating submersible pump 3. A complete fermentation system is connected by pipelines or lines. The pipeline connection mode: the steam outlet of the ultrasonic humidifier 11 is connected with the air inlet of the fermenter with a steam pipeline 10 (1-inch plastic water pipe). The oxygen pump 13 is connected to the fermenter 9 through the oxygen pipeline 12 . The outlet water of the circulating submersible pump 3 is connected to the water inlet of the fermenter 9 through the circulating water inlet pipe 5, and then the outlet water of the fermenter is connected through the circulating water outlet pipe 4, and the heating/cooling water is directly discharged back into the electric hot water container 2; Insert the probe into the temperature probe socket 9-11 (see Figure 4) of the fermentation tank and put it to the bottom, and connect the fermentation automatic control system 1 through the temperature probe line 6; Plug it to prevent the backflow of air from bringing pollution. The fermentation automatic control system 1 is connected with a power socket 8 through a power cord 7 . Fermentation tank 9 is installed on the fermentation tank support 14, and the sponge insulation cover can be added outside the tank.

See Fig. 2 in combination, wherein the fermenter 9 is all made of stainless steel, can hold 250kg of solid fermentation material, and a perforated water filter 9-7 is arranged at the bottom, and is evenly arranged around the center of the perforated water filter and the fermenter Circulating water insulation pipe 9-5 is arranged, and the two ends of circulating water insulation pipe 9-5 are connected with external electric hot water container 2 by water inlet and outlet pipelines, and automatic control valve 9-3 is arranged on it, forms circulation. The perforated tube 9-4 for oxygen ventilation is evenly distributed in the fermentation tank, and the perforated tube 9-4 for oxygen ventilation is connected to the external ultrasonic humidifier 11 and oxygen pump 13 for oxygen supply and ventilation. Referring to Fig. 3, there are two circular sampling holes 9-12, an air outlet 9-10, a temperature probe jack 9-11 and two observation windows 9-9 on the fermenter cover 9-1. The bottom of the fermentation tank has a discharge hole 9-6 and a drain valve 9-8.

Referring again to Fig. 4, the automatic control panel is provided with a preset temperature gauge 1-1 in the fermenter, a real-time temperature display gauge 1-2 in the fermenter, a total power on button 1-3, a lock 1-4, and a total power off button 1-5, total power switch indicator light 1-6, electric hot water container and submersible pump power switch 1-7, electric hot water container and submersible pump power switch indicator light 1-8.

The control principle of this system is shown in Figure 5. The required temperature is set through the temperature presetter, the temperature controller controls the heating of the water in the electric hot water tank, and the circulating pump is controlled to provide circulating water for the fermentation tank, and the temperature probe senses the temperature in the tank. The temperature is displayed through the temperature controller control. The relay protector and air switch are used to protect the electric hot water bucket and circulation pump.

The operation process of the whole device:

Before use, the system fully sterilizes the interior of the fermenter in advance, and uses the method of connecting the pipeline to steam through the autoclave or directly sprays sterilizing with 10% sodium hypochlorite. It has been proved by experiments that after spraying with 10% sodium hypochlorite Closing the lid of the solid fermenter for 40 minutes can completely achieve the purpose of sterility. This method is safe and simple. Inject no less than 2/3 of the total capacity of tap water into the electric hot water tank (dry boiling is not allowed); insert the temperature probe into the socket of the fermenter, connect the ventilation pipes, oxygen pipes and temperature probes; set the electric water tank to the preset temperature 45°C (the highest temperature value of circulating water); then turn on the power, set the temperature required for fermentation on the control box, and then put a part of the sterilized solid fermentation substrate into the fermenter to cool, and put it into the ultra-clean Cool in the workbench. After cooling, start inoculation. The bacteria are the white rot fungus composite bacteria that have been domesticated and cultivated in the papermaking raw materials (sawdust or bamboo). The method of inoculation is carried out in layers, which can save the step of stirring , and then ensure the normal growth of white rot fungus in the large-scale fermentation device and efficiently produce enzymes to degrade lignin. After inoculation, plug in the power supply of the three-hole plug in the distribution box, and connect to the power supply of the ultrasonic humidifier to humidify; connect to the oxygen pump to inflate; Turn on (power on) the air switch upward; press the green power switch on the control panel to connect to the main power supply, and the green light on the panel is on at this time; turn the temperature knob to the desired temperature in the fermenter (between 35°C and 40°C), and turn on Steam, oxygen, and the fermenter starts to work. Measure the temperature and humidity, and then take 10g of fermentation raw materials from the sampling port every 20d for related determination. After the fermentation is completed, press the red button to turn off the main power; press the air switch down to power off, and unplug all the power plugs; all the knobs (four) are all returned to zero; remove the ventilation and circulating water connection pipe, and take out the temperature probe; Take out the product; pour out the water in the electric hot water bucket and humidifier; clean the fermentation tank; take out the circulating water pump and dry it for storage; complete.

The following are the application examples of this system for solid fermentation of cellulose and lignin degrading enzymes in large-scale production:

According to the biological characteristics of white rot fungi, the best growth conditions for white rot fungi are 28°C to 39°C, humidity around 60%, aeration time of 2 hours per day, and pH value of around 4.5. First select the white rot fungus strain, culture it in inclined test tubes, expand the liquid in the conical flask, expand the culture in the 7L fermenter, inoculate the liquid strain into the glass bottle for solid fermentation, and domesticate it after 12 days of fermentation. Ferment in the herbaceous or woody fiber raw material inoculated in the fermenter. The liquid medium formula is L-1: glucose 10g, potassium dihydrogen phosphate 3g, magnesium sulfate 1.5g, copper sulfate 0.015g, ferrous sulfate 0.2g, manganese sulfate 0.2g, sodium tartrate 2mmol, Tween 2g, VB ₁ 0.001g. The formula of solid fermentation solution is L-1: glucose 10g, potassium dihydrogen phosphate 3g, magnesium sulfate 1.5g, copper sulfate 0.015g, ferrous sulfate 0.2g, manganese sulfate 0.2g, sodium tartrate 2mmol, Tween 2g, VB10.001g , benzyl alcohol 6mmol, H ₂ O ₂ 5g, take the mixture of bamboo and bran (mass ratio is 8:2) as white rot fungus fermentation raw material, mix with solid fermentation solution, moisture content is about 60%, pack in In a gauze bag, in a vertical autoclave, 0.5MPa, 121°C, sterilize for 30 minutes, put it into a fermenter after cooling, and inoculate in layers. The inoculum is domesticated by solid fermentation in a glass bottle for 12 days. White rot bacteria. After 10 days of natural fermentation, start to take materials, squeeze out the enzyme solution, and measure the enzyme activities of lignin peroxidase (LiP), manganese peroxidase (MnP) and laccase (Laccase), and then measure the enzyme activity every 10 days , the cellulose and lignin degradation rates were measured every 10 days.

According to the required temperature in the fermenter, set the temperature in the electric hot water barrel, which is 3-5°C higher than the preset temperature in the fermenter, and use the submersible pump to circulate the water in the water inlet and outlet pipes in the fermenter to achieve the desired effect on the fermenter. For the function of heat preservation, there is a steam pipe connected between the humidifier and the fermenter to achieve the effect of moisturizing the white rot fungus solid fermentation process, and the temperature and humidity in the fermenter are measured by a thermo-hygrometer. An oxygen pipe is connected between one end of the oxygen pump and the fermenter to achieve the effect of passing oxygen, and the control box is used to control the temperature parameters. After these pipes are connected, the fermenter can work normally.

The following is a comparative experiment:

The laboratory has confirmed that the composite strains of Phanerochaete chrysosporium, Trametes vermilion (purchased from the Institute of Microbiology, Chinese Academy of Sciences), and Pleurotus ostreatus (purchased from the Chongqing Institute of Agricultural Sciences) were used to inoculate bamboo as a The results of solid fermentation in the raw materials showed that the degradation degree of lignin and hemicellulose, the loss of dry matter of bamboo before and after treatment, and the digestibility of dry matter in the body of bamboo treated with white rot fungi under different culture conditions were all the same. There is a big difference, the temperature affects the solid fermentation time of white rot fungi and the degradation rate of bamboo lignin. At the same time, the suitable growth temperature of different strains is not the same. The optimum temperature for the strains selected in the experiment is between 28 and 32°C. In terms of moisture content and ventilation, there is often an interaction. If the moisture content of the treated bamboo is too low, the growth of mycelia will be inhibited. Excessive water content will lead to poor ventilation and affect the introduction of _O2 , and the _CO2 and heat generated during the fermentation process will not be dissipated in time, which is unfavorable to the growth of mycelia. The experimental results show that since the degradation of lignin by white-rot fungi is largely an oxidation process, oxygenation is a necessary condition for the production of lignin peroxidase when cultivating the three required strains, otherwise no lignin peroxidase will be produced. Enzymes or enzymes are rarely produced. Therefore, under the condition of maintaining a suitable moisture content in bamboo, sufficient oxygen supply is very important for the growth and treatment effect of white rot fungi. The total moisture of solid fermented bamboo should be controlled at 3:1, which is the best. In addition to the aforementioned influencing factors, white rot fungi require a sterile and highly aerobic environment in the substrate to initiate growth. In the presence of miscellaneous bacteria, miscellaneous bacteria may dominate, resulting in failure of treatment. Therefore, in order to achieve the purpose of improving the digestibility of bamboo, it is necessary to inhibit the growth of unfavorable bacteria.

White-rot fungi have been found to have the ability to synthesize and secrete a variety of extracellular peroxidases, and they can produce lignin peroxidase, manganese peroxidase and laccase on bamboo. Among them, LiP and MnP are two key enzymes in the degradation of lignin. With the participation of molecular oxygen, a series of free radical chain reactions are triggered by the H ₂ O ₂ formed by themselves, and the lignin in bamboo wood is completely oxidized. However, the types and activities of enzymes produced by the three different strains were different, which directly affected the degradation effect of bamboo. It can be seen from the figure that when the bamboo was treated with Phanerochaete chrysosporium, Trametes vermilion and Pleurotus ostreatus as strains, the activity of lignin peroxidase reached the maximum on the 9th day, which was 28.3 U/g. The activity of manganese peroxidase reached the maximum value of 12.6 U/g on the 8th day. It shows that these three strains can produce lignin peroxidase, manganese peroxidase and laccase with high activity, and they are excellent strains for degrading bamboo.

Table 1 Effect of white rot fungus treatment time on the degradation rate of main components of bamboo

A set of data obtained when using other devices to degrade bamboo fermentation with white rot fungi is:

Table 2 Effect of white rot fungus treatment time on the degradation rate of main components of bamboo

From the comparison of Table 1 and Table 2, it can be seen that the application of this device to ferment papermaking raw materials has greatly improved the efficient degradation of lignin, and the lignin degradation rate is significantly higher than that of the previous solid fermentation device. The same fiber The degradation rate of lignin is lower, which is the ideal effect most needed in papermaking production, that is, efficient degradation of lignin and lower degradation of cellulose, so as to ensure the saving and full utilization of papermaking raw materials. The efficient degradation of lignin can reduce the chemical pollution caused by the degradation of lignin by strong alkali in the paper industry and the waste water pollution. This has a very obvious effect on environmental protection.

Claims (7)

1. The white rot fungus solid fermentation system, including a control system and a fermentation reactor, is characterized in that: it also includes a heating system connected to the fermentation reactor, a humidifier, and an oxygen pump; the center of the fermentation reactor is evenly arranged with circulation The water insulated pipe and the circulating water insulated pipe are connected to the heating system provided separately outside the fermentation reactor to form a heating circuit; the humidifier and the oxygen pump are respectively connected to the fermentation reactor through the steam pipe and the oxygen pipe, and the steam pipe It is also uniformly arranged around the center of the fermentation reactor; the bottom of the fermentation reactor is provided with a water filter; the fermentation reactor has a sampling port, an air outlet and an observation window, and a temperature probe is provided in the fermentation reactor; The heating system, humidifier, oxygen pump, and temperature probe are all connected to the control system through control lines or signal lines, and the control system has a control panel for displaying and setting temperature and humidity. 2. The white rot fungus solid fermentation system according to claim 1, characterized in that: the heating system is an electric hot water container, which is connected to the circulating water insulation pipe in the fermentation reactor through a circulation pipeline; The water is controlled by the submersible pump, and both the electric hot water container and the submersible pump are connected to the control system through the control line. 3. The white-rot fungus solid fermentation system according to claim 1 or 2, characterized in that: the fermentation reactor is a fermenter or a fermenter structure. 4. The white-rot fungus solid fermentation system according to claim 3, characterized in that: the automatic control panel is provided with a preset temperature gauge in the fermentation reactor, a real-time display of the temperature in the fermentation reactor, a general power on button, Lock, main power off button, main power switch indicator light, heating system and submersible pump power switch and heating system and submersible pump power switch indicator light. 5. The white rot fungus solid fermentation system according to claim 4, characterized in that: the oxygen pump is provided with a sterilizing filter membrane. 6. The white rot fungus solid fermentation system according to claim 5, characterized in that: a layer of sponge insulation is wrapped around the fermentation reactor. 7. The white rot fungus solid fermentation system according to claim 6, characterized in that: there is a discharge hole that can be automatically closed or opened at the bottom of the fermentation reactor or the tank body.

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