A kind of pseudoxanthomonas for effectively enhancing the cellulose conversion ability of natural flora and its application

Abstract

The present invention relates to the field of microbial technology, and in particular to a pseudoxanthomonas that efficiently enhances the cellulose conversion ability of natural flora and its application. The present invention isolates a strain of Pseudoxanthomonas (Pseudoxanthomonas suwonensis) AGIS‑SC‑Cluster‑1 from wheat field soil collected in Jining City, Shandong Province, and deposits it in the China Center for Type Culture Collection on August 31, 2022, with a deposit number of CGMCCNO: 25617. The strain has the ability to degrade lignocellulose and adsorb surrounding microorganisms to form flocculent bacterial clusters, which greatly shortens the distance between local microorganisms on the substrate, significantly enhances the synergistic effect between bacteria, and thereby improves the degradation efficiency of lignocellulose, and significantly increases hydrogen production and alcohol production.

Description

Technical Field

[0001] The invention relates to the technical field of microorganisms, and in particular to a pseudoxanthomonas capable of efficiently enhancing the cellulose conversion ability of natural flora and an application thereof. Background Art

[0002] Hydrogen energy and biofuels are regarded as the cleanest energy with the greatest development potential in the 21st century. They are the only alternatives to fossil fuel energy and are expected to play an important role in achieving the goal of "carbon neutrality". Lignocellulose, which exists in the form of agricultural waste, is the polysaccharide with the highest production and reserves in nature. Using it as a raw material to produce hydrogen and biofuel substances such as acetic acid and butyric acid is considered to be a sustainable and low-cost way to achieve carbon neutrality. The structure of lignocellulose is extremely complex, and it is difficult to achieve efficient degradation and hydrogen production using a single microorganism. A mixed system of multiple strains helps to optimize the cellulase system through interbacterial synergy and significantly increase the cellulose degradation rate.

[0003] However, composite microorganisms still face many problems in converting lignocellulose to hydrogen and biofuels. On the one hand, since cellulose degradation is relatively difficult, how to obtain an efficient cellulose degradation system and provide more abundant substrates and energy for hydrogen production is still one of the core issues. At the same time, since the composite bacterial community improves the degradation efficiency and relieves product inhibition through the synergy of multiple bacteria, in the actual fermentation process, due to the dilution of the culture medium and the adsorption of the cellulose substrate, there is often a large physical distance between the bacteria, which reduces the efficiency of the synergistic effect. In addition, the large number of harmful products in the pre-treatment of lignocellulose, the weak conversion effect of the composite bacterial community, and the high complexity of the operation limit its further application. Summary of the invention

[0004] In view of this, the present invention provides a Pseudoxanthomonas strain that can efficiently enhance the cellulose conversion ability of natural flora and its application. The strain has the ability to degrade cellulose and adsorb surrounding microorganisms to form flocculent bacterial clusters. It can cooperate with other strains to improve the degradation rate of cellulose and significantly increase the hydrogen and alcohol production.

[0005] Application of Pseudo-xanthomonas in the preparation of hydrogen- and alcohol-producing engineered bacterial flora; comprising: adding Pseudo-xanthomonas to natural bacterial flora that produce hydrogen and alcohol, domesticating and strengthening the bacterial flora, and obtaining hydrogen- and alcohol-producing engineered bacterial flora;

[0006] The natural bacterial flora for producing hydrogen and alcohol is prepared by fermentation using field compost, humus soil at the bottom of straw stacks or rotten crop straws as raw materials.

[0007] In some specific embodiments, the Pseudoxanthomonas is Pseudoxanthomonas suwonensis with a deposit number of CGMCC NO:25617.

[0008] The present invention has found through research that adding Pseudoxanthomonas to the natural bacterial flora that produces hydrogen and alcohol can regulate the growth of the bacterial flora, achieve local enrichment of microorganisms in the bacterial flora on the substrate, and significantly enhance the synergistic effect between bacteria, thereby obtaining a stable functional bacterial flora with significant ability to convert cellulose to produce hydrogen.

[0009] In the present invention, the Pseudocanthomonas is preferably a strain with a deposit number of CGMCC NO:25617.

[0010] In the present invention, the natural bacterial flora producing hydrogen and alcohol is prepared by the following method:

[0011] Take field compost, humus soil at the bottom of straw stacks or rotten crop straw, add alkali-treated straw extract and ferment and culture to obtain hydrogen- and alcohol-producing bacterial flora.

[0012] In the present invention, the alkali-treated extract of straw can be prepared according to the conventional alkali treatment in the field; there are no special requirements for the specific type and concentration of the alkali, and the common types in the field can be used. There are no special requirements for the type of straw, and the common types in the field can be used, such as wheat straw, corn straw, etc. In some specific embodiments of the present invention, the straw is alkali-treated with a NaOH aqueous solution with a concentration of 1% (m / v) to prepare the alkali-treated extract of straw. Specifically, referring to the method of pretreating wheat straw by alkali distillation in the patent "A method for bioconversion of cellulose by artificial flora" with application number 201811600068.8, the straw is treated, and the liquid flowing out of the water washing in step (3) is collected to obtain the alkali-treated extract. The specific steps are as follows:

[0013] (1) Take 1 kg of crushed wheat straw, add a 1% (m / v) NaOH aqueous solution (containing 5 g of NaOH), and mix well.

[0014] (2) After completing step (1), the wheat straw is placed in a distillation kettle and treated with 120° C. saturated steam for 30 minutes.

[0015] (3) After completing step (2), hydrochloric acid is added to the wheat straw to adjust the pH value to between 6 and 8, and then the wheat straw is washed with water until no black liquid flows out, and then dried to obtain pretreated wheat straw.

[0016] In the present invention, the fermentation and culture system refers to the system containing cellulose in the patent "A method for bioconversion of cellulose by artificial flora" with application number 201811600068.8. In addition to field compost, humus soil at the bottom of straw stacks or rotten crop straw, the fermentation and culture system also includes the following components:

[0017] KH2PO4, K2HPO4, urea, MgCl2·6H2O, CaCl2·2H2O, L-cysteine, FeSO4, resazurin, morpholinopropane sulfonic acid, pyridoxamine hydrochloride, biotin, p-aminobenzoic acid, vitamin B2 and sodium citrate, and water is added to 1 L, and the pH of the fermentation system is 7.4.

[0018] In some specific embodiments, the fermentation culture system of the present invention includes the following components:

[0019] 1.5gKH2PO4, 2.9g K2HPO4, 2.1g urea, 1.0gMgCl2·6H2O, 150mg CaCl2·2H2O, 1.0gL-cysteine, 1.25mg FeSO4, 2.0mg resazurin, 10.0g morpholinopropane sulfonic acid, 2.0mg pyridoxamine hydrochloride, 0.2mg biotin, 0.4mg p-aminobenzoic acid, 0.2mg vitamin B2 and 3.0g sodium citrate, water is added to 1L, and the pH of the fermentation system is 7.4.

[0020] The invention separates and obtains strain AGIS-SC-Cluster-1 from wheat field soil collected in Jining City, Shandong Province, and the strain is identified as Pseudoxanthomonas suwonensis, and the preservation number thereof is CGMCC NO:25617.

[0021] The present invention also provides a hydrogen- and alcohol-producing engineering bacterial group, comprising Pseudocantia spp. and at least one of the following bacteria:

[0022] Thermoanaerobacterium, Clostridium, Rhizobium, Tepidanaerobacter, Bacillus, Symbiobacterium and Methanoculleus.

[0023] In some specific embodiments, the Pseudocanthomonas is a strain with a deposit number of CGMCC NO:25617.

[0024] In the present invention, the hydrogen- and alcohol-producing engineering bacteria are composed of thermophilic anaerobic bacteria, Clostridium pasteurianum and the pseudoxanthomonas of the present invention; the effective bacterial number ratio of the thermophilic anaerobic bacteria, Clostridium pasteurianum and pseudoxanthomonas is 30-50:20-40:10-30; in some specific embodiments, the effective bacterial number ratio is specifically 40:30:20. ;

[0025] In the present invention, the hydrogen-producing and alcohol-producing engineering bacterial community is composed of rhizobia, thermophilic bacteria, Clostridium pasteurianum, Bacillus and the pseudoxanthomonas; the effective bacterial number ratio of the rhizobia, thermophilic bacteria, Clostridium pasteurianum, Bacillus and pseudoxanthomonas is 5-15:10-25:15-35:10-30:5-25; in some specific embodiments, the effective bacterial number ratio is specifically 10:15:25:25:15.

[0026] In the present invention, the hydrogen-producing and alcohol-producing engineering bacteria group is composed of Thermobacterium pyrostei, Methanobacterium saccharum, Clostridium pasteurianum, Thermoanaerobic Bacillus and Pseudocantia spp.; the effective bacterial number ratio of Thermobacterium pyrostei, Methanobacterium pyrostei, Clostridium pasteurianum, Thermoanaerobic Bacillus and Pseudocantia spp. is 5-15:10-20:15-25:25-35:10-20; in some specific embodiments, the effective bacterial number ratio is specifically 10:16:20:30:14.

[0027] The present invention found that the strain AGIS-SC-Cluster-1 has the ability to degrade cellulose and adsorb surrounding microorganisms to form flocculent bacterial clusters, which greatly shortens the distance between local microorganisms on the substrate, significantly enhances the synergistic effect between bacteria, thereby improving the degradation efficiency of cellulose and significantly increasing hydrogen production.

[0028] Therefore, the present invention also provides the use of the Pseudocanthomonas or the composite bacteria in fermentation to produce hydrogen and alcohol, or in the preparation of a microbial agent for fermentation to produce hydrogen and alcohol.

[0029] In the present invention, the fermentation substrate is lignocellulose or a material containing lignocellulose.

[0030] The lignocellulose-containing material includes at least one of rice straw, wheat straw, corn straw, soybean straw, shrub dead branches, waste paper and the like.

[0031] The present invention also provides a microbial agent for producing hydrogen and alcohol by fermentation, comprising the pseudoxanthomonas described in the present invention or the composite bacteria described in the present invention, and an acceptable auxiliary agent.

[0032] In the present invention, there is no particular limitation on the specific types of acceptable auxiliary agents, and any common auxiliary agents in the art may be used.

[0033] The present invention also provides a method for producing hydrogen by fermentation, which uses lignocellulose or a material containing lignocellulose as a substrate and employs the composite bacteria of the present invention for fermentation.

[0034] In some embodiments, the fermentation is drum bottle fermentation; the fermentation temperature is 30-60° C. and the fermentation time is 3 days to 30 days.

[0035] The strain AGIS-SC-Cluster-1 provided by the present invention has the ability to degrade lignocellulose and adsorb surrounding microorganisms to form flocculated bacterial clusters, which greatly shortens the distance between local microorganisms on the substrate, significantly enhances the synergistic effect between bacteria, thereby improving the degradation efficiency of lignocellulose, and significantly increasing the hydrogen and alcohol production.

[0036] Biological Deposit Description

[0037] Pseudoxanthomonas suwonensis was deposited on August 31, 2022 at the General Microbiology Center of China Culture Collection Administration, Institute of Microbiology, Chinese Academy of Sciences, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, with the deposit number CGMCC No.25617. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 Schematic diagram of a drum fermentation bottle; A is a schematic diagram of a drum fermentation bottle; B is a schematic diagram of a front view of the drum fermentation process; C is a schematic diagram of a top view of the drum fermentation process;

[0039] Figure 2 The highest production of hydrogen, ethanol, acetic acid and butyric acid during the fermentation process of the bacterial community in Example 1 (*: p < 0.05);

[0040] Figure 3 The highest production of hydrogen, ethanol, acetic acid and butyric acid during fermentation of bacterial colonies B and BP (*: p < 0.05);

[0041] Figure 4 The highest production of hydrogen, ethanol, acetic acid and butyric acid during the fermentation of the bacterial community in Example 3 (*: p < 0.05);

[0042] Figure 5 The highest production of hydrogen, ethanol, acetic acid and butyric acid during the fermentation of bacterial colony A and bacterial colony APT;

[0043] Figure 6 The highest production of hydrogen, ethanol, acetic acid and butyric acid during the fermentation of bacterial colony B and bacterial colony BPT;

[0044] Figure 7 The maximum production of hydrogen, ethanol, acetic acid and butyric acid during the fermentation process of the bacterial community in Comparative Example 3. DETAILED DESCRIPTION

[0045] The present invention discloses a Pseudo-xanthomonas bacteria with high efficiency and enhanced cellulose conversion capacity of natural flora and its application. Those skilled in the art can refer to the content of this article and appropriately improve the process parameters to achieve it. It is particularly important to point out that all similar substitutions and modifications are obvious to those skilled in the art, and they are all considered to be included in the present invention. The methods and applications of the present invention have been described through preferred embodiments, and relevant personnel can obviously modify or appropriately change and combine the methods and applications described herein without departing from the content, spirit and scope of the present invention to implement and apply the technology of the present invention.

[0046] The present invention will be further described below in conjunction with embodiments:

[0047] Example 1

[0048] 1. Screening of natural microbial flora

[0049] 5 g of the mixture was taken from the field compost at a depth of 5-10 cm, and the restricted culture medium 1 (see paragraph 0075 of the specification) described in the specific implementation method of "A method for bioconversion of cellulose by an artificial bacterial community" (201811600068.8) was added with 2 mL of filtered and sterilized alkali-treated extract for culture, and a stable microbial community A was screened and obtained; the community A included strains of Thermoanaerobacterium, Clostridium, Bacillus, and Ureibacillus.

[0050] 2. Domestication and strengthening of bacterial flora

[0051] 5 g / L of calcium hydrogen phosphate, 0.1 g / L of 2-bromoethane sulfonic acid (BES), and 0.1 mL / L of dichloromethane were further added to the culture medium, and P. suwonensis (China Microorganism Collection Center CGMCCNO: 25617) was added to the bacterial community A at a ratio of 5:1 by wet weight of the bacteria. After 10 consecutive subcultures using the above culture medium, a stable microbial community AP was obtained.

[0052] 3. Result: Natural flora A and enhanced flora AP were obtained

[0053] Sequencing analysis showed that the main strains in the new bacterial community AP included Thermoanaerobacterium, Clostridium, and Pseudomonas, among which the ratio of Thermoanaerobacterium, Clostridium, and Pseudomonas was approximately 40:30:20.

[0054] Example 2

[0055] 1. Screening of natural microbial flora

[0056] Take 5 g of the mixture from the humus soil at the bottom of the straw stack, add the restrictive culture medium 1 (line 0075) described in the specific implementation method of "A method for cellulose bioconversion by an artificial bacterial community" (201811600068.8), add 2 mL of filtered and sterilized alkali-treated extract and then culture it to screen and obtain a stable microbial community B; it was identified that community B included strains of Rhizobium, Tepidanaerobacter, Clostridium, Bacillus, Pseudomonas, and Ureibacillus.

[0057] 2. Domestication and strengthening of bacterial flora

[0058] 5 g / L of calcium hydrogen phosphate, 0.1 g / L of 2-bromoethane sulfonic acid (BES), and 0.1 mL / L of dichloromethane were further added to the culture medium, and P. suwonensis (China Microorganism Collection Center CGMCCNO: 25617) was added to the bacterial community B at a ratio of 5:1 by wet weight of the bacteria. After 10 consecutive subcultures using the above culture medium, a stable microbial community BP was obtained.

[0059] 3. Results:

[0060] Get natural flora B and enhanced flora BP

[0061] Sequencing analysis showed that the main strains in the new bacterial community BP included Rhizobium, Tepidanaerobacter, Clostridium, Bacillus, and Pseudomonas, with a ratio of approximately 10:15:25:25:15.

[0062] Example 3

[0063] 1. Screening of natural microbial flora

[0064] 5 g of severely rotten straw was taken from a rural straw pile, and cultured with the culture medium described in "A method for cellulose bioconversion using an artificial bacterial community" (201811600068.8) after adding 2 mL of filtered and sterilized alkali-treated extract to obtain a stable microbial community C. It was identified that community C included strains of Symbiobacterium, Methanoculleus, Clostridium, Thermoanaerobacterium, Pseudomonas, and Bacillus.

[0065] 2. Domestication and strengthening of bacterial flora

[0066] 5 g / L of calcium hydrogen phosphate, 0.1 g / L of 2-bromoethane sulfonic acid (BES), and 0.1 mL / L of dichloromethane were further added to the culture medium, and P. suwonensis (China Microorganism Collection Center CGMCC: 25617) was added to the bacterial community C at a ratio of 5:1 by wet weight of the bacteria. After 10 consecutive subcultures using the above culture medium, a stable microbial community CP was obtained.

[0067] 3. Results:

[0068] The natural flora C and the enhanced flora CP were obtained. Sequencing analysis showed that the main constituent strains of the new flora CP included Symbiobacterium, Methanoculleus, Clostridium, Thermoanaerobacterium, and Pseudomonas, with a ratio of about 10:16:20:30:14.

[0069] Application effect test example 1 Comparison of hydrogen production capacity between enhanced bacterial flora and natural bacterial flora

[0070] 1. Preparation of bacterial flora:

[0071] Take the bacterial community A and the corresponding domesticated bacterial community AP, the bacterial community B and the corresponding domesticated bacterial community BP, and the bacterial community C and the corresponding domesticated bacterial community CP obtained in the preparation example, and add 2mL of filtered and sterilized alkali-treated extract, 5g / L calcium hydrogen phosphate, 0.1g / L 2-bromoethanesulfonic acid (BES), and 0.1mL / L dichloromethane to the culture medium described in "A method for cellulose bioconversion by artificial bacterial community" (201811600068.8), and culture each bacterial community to obtain fermentation seed liquid.

[0072] 2. Fermentation culture:

[0073] In a rotary drum reactor ( Figure 1 As shown in the figure, lignocellulose was used as substrate, the substrate concentration was 30 g / L of absolute dry substrate modified culture medium, and it was sterilized at 121°C for standby use; bacterial groups A, AP, B, BP, C and CP were used as fermentation strains, and the inoculation amount was 20 g / L of wet bacteria culture medium; the fermentation experiment was carried out at 50°C. The generated gas was collected by using an air bag, and continuous sampling was performed during the fermentation process to detect the content of hydrogen, ethanol, acetic acid and butyric acid at the end of the fermentation.

[0074] Gas chromatography detection of hydrogen content: 0.2 mL of the collected gas was taken with a gas chromatography injection needle for gas chromatography (Thermo Fisher 1310) detection. Detection conditions: chromatographic column, 13X molecular sieve packed column; detector TCD, temperature 250°C; injection port temperature 80°C; column box temperature 80°C; carrier gas, nitrogen; flow rate, 10 mL / min. Hydrogen standard gas was used for quantitative calculation.

[0075] Liquid chromatography detection of ethanol, acetic acid and butyric acid content: 0.1 mL of bacterial solution was added to 0.9 mL of saturated NaCl solution at pH 2.0, mixed and centrifuged at 10000 rpm for 5 min, the supernatant was filtered with a 0.22 μm filter membrane, and detected by liquid chromatography (Agilent 1260). Detection conditions: chromatographic column, Aminex HPX-87H, 300×7.8 mm, column temperature 60°C; detector, differential detector (RID), temperature 55°C; mobile phase 5 mmol / L sulfuric acid, flow rate 0.5 mL / min. Standard curves were prepared using standard products for quantitative calculation.

[0076] 3. Results:

[0077] The fermentation results are as follows Figure 2 , Figure 3 , Figure 4 shown.

[0078] 4. Discussion

[0079] The results showed that compared with the original bacterial groups A, B and C screened from materials from different sources, the bacterial groups domesticated with P.suwonensis (China Microbiological Collection Center CGMCC NO: 25617) showed significant improvement in hydrogen production capacity, P < 0.05; at the same time, the ethanol production capacity of bacterial groups AP and CP was significantly improved compared with the original bacterial groups A and C, P < 0.05; the acetic acid production capacity of bacterial group BP was significantly improved compared with the original bacterial group B, P < 0.05. The above results show that the bacterial group domesticated with P.suwonensis (China Microbiological Collection Center CGMCC NO: 25617) has achieved an unexpected and significant improvement in hydrogen production capacity compared with the original bacterial group. The use of the strain of the present invention can significantly improve the hydrogen production capacity of different bacterial groups, and can also increase the yield of other by-products to a certain extent.

[0080] Application effect test example 2 Comparison of hydrogen production capacity of different strains of enhanced bacterial flora

[0081] 1. Preparation of bacterial flora:

[0082] Taking bacterial colonies A, B, and C as the initial bacterial colonies, 5 g / L calcium hydrogen phosphate, 0.1 g / L 2-bromoethane sulfonic acid (BES), and 0.1 mL / L dichloromethane were added to the culture medium, and then P. taiwanensis (China Microorganism Collection Center CGMCC1.10867) was added to the bacterial colonies at a ratio of 5:1 by wet weight of the bacteria. After 10 consecutive subcultures using the above culture medium, stable microbial colonies APT, BPT, and CPT were obtained.

[0083] 2. Fermentation culture:

[0084] In a rotary drum reactor (such as Figure 1 ) used lignocellulose as substrate, the substrate concentration was 30 g / L of absolute dry substrate modified culture medium, sterilized at 121°C for later use; bacterial groups A, APT, B, BPT, C and CPT were used as fermentation strains, and the inoculation amount was 20 g / L of wet bacteria culture medium; the fermentation experiment was carried out at 50°C. The generated gas was collected by using an air bag, and continuous sampling was performed during the fermentation process to detect the content of hydrogen, ethanol, acetic acid and butyric acid at the end of the fermentation.

[0085] Gas chromatography detection of hydrogen content: 0.2 mL of the collected gas was taken with a gas chromatography injection needle for gas chromatography (Thermo Fisher 1310) detection. Detection conditions: chromatographic column, 13X molecular sieve packed column; detector TCD, temperature 250°C; injection port temperature 80°C; column box temperature 80°C; carrier gas, nitrogen; flow rate, 10 mL / min. Hydrogen standard gas was used for quantitative calculation.

[0086] Liquid chromatography detection of ethanol, acetic acid and butyric acid content: 0.1 mL of bacterial solution was added to 0.9 mL of saturated NaCl solution at pH 2.0, mixed and centrifuged at 10000 rpm for 5 min, the supernatant was filtered with a 0.22 μm filter membrane, and detected by liquid chromatography (Agilent 1260). Detection conditions: chromatographic column, Aminex HPX-87H, 300×7.8 mm, column temperature 60°C; detector, differential detector (RID), temperature 55°C; mobile phase 5 mmol / L sulfuric acid, flow rate 0.5 mL / min. Standard curves were prepared using standard products for quantitative calculation.

[0087] 3. Results:

[0088] The fermentation results are as follows Figure 2 , Figure 3 , Figure 4 And as shown in Table 1.

[0089] Table 1

[0090]

[0091] ↑ and ↓ indicate an increase and decrease in content, respectively; - indicates that there is basically no difference in content; ↑↑ and ↓↓ indicate a significant increase and decrease in content (p<0.05).

[0092] 4. Discussion

[0093] The results show that compared with the original flora A, B, and C, only the CPT flora has a certain improvement in hydrogen production and alcohol production, and the fermentation performance of flora APT and BPT has even decreased. Compared with the domesticated flora AP, BP, and CP obtained by using P.suwonensis (China Microbiological Collection Center CGMCC NO: 25617) in the present invention (see Table 1), the new flora APT, BPT, and CPT domesticated by using P.taiwanensis (China Microbiological Collection Center CGMCC1.10867) have significantly decreased hydrogen production and alcohol production performance, indicating that the performance of the hydrogen and alcohol production flora obtained by flora domestication based on P.suwonensis (China Microbiological Collection Center CGMCC) has been significantly improved, which cannot be replicated by other strains of the same genus (such as P.taiwanensis).

[0094] Application effect test example 3 Comparison of hydrogen production capacity of different subspecies strains

[0095] 1. Preparation of bacterial flora:

[0096] Taking bacterial colonies A, B, and C as the initial bacterial colonies, 5 g / L calcium hydrogen phosphate, 0.1 g / L 2-bromoethane sulfonic acid (BES), and 0.1 mL / L dichloromethane were added to the culture medium, and then P. suwonensis (DSM 17175, German Collection of Microorganisms and Cells) was added to the bacterial colonies at a ratio of 5:1 based on the wet weight of the bacteria. After 10 consecutive subcultures using the above culture medium, stable microbial colonies AP2, BP2, and CP2 were obtained.

[0097] 2. Fermentation culture:

[0098] In a rotary drum reactor (such as Figure 1 ) used lignocellulose as substrate, the substrate concentration was 30 g / L of absolute dry substrate modified culture medium, sterilized at 121°C for later use; bacterial groups A, AP2, B, BP2, C and CP2 were used as fermentation strains, and the inoculation amount was 20 g / L of wet bacteria culture medium; the fermentation experiment was carried out at 50°C. The generated gas was collected by using an air bag, and continuous sampling was performed during the fermentation process to detect the content of hydrogen, ethanol, acetic acid and butyric acid at the end of the fermentation.

[0099] Gas chromatography detection of hydrogen content: 0.2 mL of the collected gas was taken with a gas chromatography injection needle for gas chromatography (Thermo Fisher 1310) detection. Detection conditions: chromatographic column, 13X molecular sieve packed column; detector TCD, temperature 250°C; injection port temperature 80°C; column box temperature 80°C; carrier gas, nitrogen; flow rate, 10 mL / min. Hydrogen standard gas was used for quantitative calculation.

[0100] Liquid chromatography detection of ethanol, acetic acid and butyric acid content: 0.1 mL of bacterial solution was added to 0.9 mL of saturated NaCl solution at pH 2.0, mixed and centrifuged at 10000 rpm for 5 min, the supernatant was filtered with a 0.22 μm filter membrane, and detected by liquid chromatography (Agilent 1260). Detection conditions: chromatographic column, Aminex HPX-87H, 300×7.8 mm, column temperature 60°C; detector, differential detector (RID), temperature 55°C; mobile phase 5 mmol / L sulfuric acid, flow rate 0.5 mL / min. Standard curves were prepared using standard products for quantitative calculation.

[0101] 3. Results:

[0102] The fermentation results are as follows Figure 5 , Figure 6 and Figure 7 shown.

[0103] The above results show that compared with the original bacterial colonies A, B, and C, among the new bacterial colonies AP2, BP2, and CP2 domesticated with P. suwonensis (DSM 17175, German Collection of Microorganisms and Cells), only the CP2 colony showed a certain improvement in hydrogen production, and the overall fermentation performance of the colonies AP2 and BP2 decreased compared with the original colonies, indicating that the performance of the hydrogen-producing and alcohol-producing bacterial colonies obtained by bacterial colony domestication based on P. suwonensis (CGMCC NO: 25617, China Microorganism Collection Center) has been significantly improved, which cannot be replicated by other strains of the same species (P. suwonensis (DSM 17175, German Collection of Microorganisms and Cells)).

[0104] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. Pseudoxanthomonas with a deposit number of CGMCC NO: 25617 ( Pseudoxanthomonas suwonensis ).

2. The use of the pseudoxanthomonas according to claim 1 in preparing an engineering bacterial population for producing hydrogen and alcohol, characterized in that: Adding the pseudoxanthomonas described in claim 1 to the natural bacterial flora that produces hydrogen and alcohol, domesticating and strengthening the bacterial flora, and obtaining an engineered bacterial flora that produces hydrogen and alcohol; The natural bacterial flora for producing hydrogen and alcohol is prepared by fermentation using field compost, humus soil at the bottom of straw stacks or rotten crop straws as raw materials.

3. The use according to claim 2, characterized in that: The natural bacterial flora producing hydrogen and alcohol is prepared by the following method: Take field compost, humus soil at the bottom of straw stacks or rotten crop straw, add alkali-treated straw extract and perform fermentation culture to obtain natural bacteria that produce hydrogen and alcohol; The fermentation culture system also includes the following components: KH2PO4, K2HPO4, urea, MgCl2·6H2O, CaCl2·2H2O, L-cysteine, FeSO4, resazurin, morpholinopropane sulfonic acid, pyridoxamine hydrochloride, biotin, p-aminobenzoic acid, vitamin B2, sodium citrate and water, and the pH of the fermentation system is 7.

4.

4. A method for preparing a hydrogen- and alcohol-producing engineered bacterial community, characterized in that: Field compost, humus soil at the bottom of straw stacks or rotten crop straw are taken, and an alkali-treated extract of the straw is added for fermentation culture to obtain a natural bacterial community that produces hydrogen and alcohol; the pseudoxanthomonas described in claim 1 is added to the natural bacterial community that produces hydrogen and alcohol, and the bacterial community is domesticated and strengthened to obtain an engineered bacterial community that produces hydrogen and alcohol.

5. Use of the Pseudoxanthomonas according to claim 1 in fermentation to produce hydrogen and alcohol or in the preparation of a microbial agent for fermentation to produce hydrogen and alcohol.

6. The use according to claim 5, characterized in that: The fermentation substrate is lignocellulose or a material containing lignocellulose; the material containing lignocellulose includes at least one of rice straw, wheat straw, corn straw, soybean straw, shrub dead branches, and waste paper.

7. A microbial agent for producing hydrogen and alcohol by fermentation, characterized in that: The invention comprises the pseudoxanthomonas as claimed in claim 1, and an acceptable auxiliary agent.

8. A method for producing hydrogen and alcohol by fermentation, characterized in that: The fermentation is carried out using lignocellulose or lignocellulose-containing materials as substrates and the microbial agent described in claim 7.

9. The method according to claim 8, characterized in that The fermentation is drum bottle fermentation; the fermentation temperature is 30-60°C and the fermentation time is 3 days to 30 days.

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