High-salt-tolerance arthrobacter pylori capable of producing protease and application of arthrobacter pylori

Abstract

The invention discloses high-salt-tolerance arthrobacter vitriomyzae capable of producing protease and application of the arthrobacter vitriomyzae, and belongs to the technical field of environmental microorganisms. The invention provides an arthrobacter pseudomonas A1 which is preserved in the China Center for Type Culture Collection on May 23, 2024, and the preservation number of the arthrobacter pseudomonas A1 is CCTCC (China Center for Type Culture Collection) NO: M 20241041. The arthrobacter sp. Can tolerate the salinity of 8.0%, and can still effectively secrete protease under the stress of high salt. The strain can provide an effective strain resource for strengthening anaerobic biological treatment of high-salt and high-protein wastewater such as kitchen wastewater, so that the treatment cost is remarkably reduced, and the strain has important application value.

Description

Technical Field

[0001] The invention belongs to the technical field of environmental microorganisms, and particularly relates to a highly salt-resistant protease-producing Arthrobacterium glabratum and an application thereof. Background Art

[0002] High-salt and high-protein wastewater mainly comes from food industries such as restaurant waste treatment and meat pickling, as well as pharmaceutical industries such as sodium heparin production. For example, restaurant wastewater is a typical high-salt and high-protein wastewater with high COD and protein concentrations. The anaerobic biological method is more suitable for the treatment of high-concentration organic wastewater, with the advantages of high organic load, low energy consumption, and small sludge production. Not only that, this high-concentration organic wastewater can also be converted into a fermentation broth rich in small-molecule organic acids through anaerobic fermentation technology, and used as a carbon source for biological denitrification in sewage treatment, thereby realizing resource utilization. In actual application, in order to avoid the pH drop caused by acid production, it is usually necessary to add alkali solution to maintain the optimal fermentation pH of microorganisms, which will cause the salinity of the fermentation system to further increase. However, since most anaerobic microorganisms have limited tolerance to salinity, how to improve the treatment efficiency in a high-salt environment is the key.

[0003] In order to improve the biological treatment efficiency of high-salt wastewater, based on the concept of bioaugmentation, it is considered an effective way to screen salt-tolerant functional bacteria and add them to the reaction system. Bioaugmentation technology does not require changes to the treatment process, has low cost of use, and shows strong application potential in wastewater treatment and pollutant biodegradation. Protein hydrolysis under high salt stress is the rate-limiting step in the anaerobic treatment of high-salt and high-protein wastewater, so it is very important to screen out highly salt-tolerant protease-producing bacteria. Summary of the invention

[0004] This patent discloses a highly salt-tolerant protease-producing Arthrobacterium glabratum and its application, which can effectively enhance the anaerobic biological treatment of high-salt and high-protein wastewater.

[0005] To achieve the above-mentioned purpose, the technical solution of the present invention is: to provide a highly salt-tolerant protease-producing original glass fly arthrobacter A1, which was deposited in the China Center for Type Culture Collection on May 23, 2024, with a preservation number of CCTCC NO: M20241041.

[0006] As a preferred improvement of the present invention, the 16S rDNA sequence of the original Arthrobacterium vitae is shown as SEQ ID NO.1.

[0007] The first object of the present invention is to provide a highly salt-tolerant protease-producing Arthrobacter protophormiae, wherein the Arthrobacter protophormiae A1 was deposited in the China Center for Type Culture Collection on May 23, 2024, with a deposit number of CCTCC NO: M 20241041.

[0008] Optionally, in some embodiments of the present invention, the Arthrobacterium truncatum secretes protease under anaerobic conditions and has a salt tolerance of 4.0% or more.

[0009] Further optionally, in some embodiments of the present invention, the salinity tolerance is up to 8.0%.

[0010] Further optionally, in some embodiments of the present invention, the salinity tolerance is 4.0%-8.0%.

[0011] Optionally, in some embodiments of the present invention, the enzyme activity of the protease reaches above 25 U / mL.

[0012] Further optionally, in some embodiments of the present invention, when the salt tolerance is 4.0%-6.0%, the enzyme activity of the protease reaches above 35 U / mL.

[0013] Further optionally, in some embodiments of the present invention, when the salt tolerance is 6.0%-8.0%, the enzyme activity of the protease reaches above 25 U / mL.

[0014] The second object of the present invention is to provide the use of Arthrobacterium protohyalii described in any one of the above items in wastewater treatment, wherein the wastewater treatment includes anaerobic fermentation of kitchen wastewater to produce organic acids.

[0015] The third object of the present invention is to provide an anaerobic fermentation inoculum of kitchen wastewater, comprising anaerobic acidogenic activated sludge and the highly salt-tolerant protease-producing Arthrobacterium glabratum as described above.

[0016] Optionally, in some embodiments of the present invention, the volume ratio of the activated liquid of Arthrobacter glabraensis to the anaerobic acidogenic activated sludge bacterial liquid is 1:5-1:15, preferably 1:10.

[0017] The fourth object of the present invention is to provide a method for producing organic acids by anaerobic fermentation of kitchen wastewater, wherein an anaerobic fermentation inoculant of kitchen wastewater is added to the kitchen wastewater, and the fermentation is carried out at pH 6.5-7.5 and 30-40°C for 18-25 days, wherein the anaerobic fermentation inoculant of kitchen wastewater is any of the anaerobic fermentation inoculants of kitchen wastewater described above.

[0018] Optionally, in some embodiments of the present invention, the initial salinity of the kitchen wastewater reaches more than 1.5%, and the maximum salinity during the fermentation process reaches more than 3.5%.

[0019] Optionally, in some embodiments of the present invention, the protein degradation rate of the kitchen wastewater is above 80%, and the total sugar degradation rate is above 90%.

[0020] Further optionally, in some embodiments of the present invention, the protein degradation rate of the kitchen wastewater is above 90%, and the total sugar degradation rate is above 95%.

[0021] Optionally, in some embodiments of the present invention, the organic acid yield reaches 50 g / L or more.

[0022] Beneficial effects: The Arthrobacterium glabratum provided by the present invention has the ability to produce protease under high salt stress, with a salt tolerance of more than 4.0%, and a maximum tolerance of 8.0%. The bacterium can significantly enhance the anaerobic treatment effect of kitchen wastewater, and can provide effective strain resources for the resource-based biological treatment of high-salt and high-protein wastewater, thereby reducing the treatment cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 : The technological process of strain screening of the present invention.

[0024] Figure 2 : Changes in COD removal efficiency during adaptive evolution.

[0025] Figure 3 : Changes in protein degradation rates during adaptive evolution.

[0026] Figure 4 : Colony morphology of strain A1.

[0027] Figure 5 : Salt tolerance of the strain.

[0028] Figure 6 :Effect of salinity on the growth of Arthrobacterium truncatum A1.

[0029] Figure 7 :Effect of salinity on protease secretion from Arthrobacterium glabratum A1.

[0030] Figure 8 :Effect of salinity on protein degradation by Arthrobacterium protothecoides A1.

[0031] Fig. 9 :Bioaugmentation effect of Arthrobacter glabrata A1 on acid production from food wastewater. DETAILED DESCRIPTION

[0032] On the one hand, the present invention discloses a highly salt-resistant protease-producing Arthrobacterium glabratum and its application, belonging to the technical field of environmental microorganisms.

[0033] like Figure 1 The process flow of screening strains of the present invention is shown, and the main steps include:

[0034] (1) First, a "top-down" adaptive evolution strategy for anaerobic bacterial communities was adopted to domesticate anaerobic bottom bacterial communities that can tolerate salinity exceeding 3.0% by gradiently increasing salt stress.

[0035] (2) Using salt-tolerant bacterial flora as the source of strains, highly salt-tolerant and protease-producing strains were screened out.

[0036] As a preferred improvement of the present invention, the salt tolerance adaptive evolution of the anaerobic bacteria is carried out in a continuous flow fully mixed anaerobic reactor, the initial inoculum is anaerobic methanogenic activated sludge, the inoculum amount is 25-35g-TS / L, peptone is the only carbon source and nitrogen source, and the influent concentration is 6.0-10.0g / L.

[0037] As a preferred improvement of the present invention, the salt tolerance adaptive evolution conditions are: temperature 30-38°C, pH 6.5-7.5, hydraulic retention time 5-10 days. On the basis of COD removal rate > 70% in the steady state period, the salt stress pressure is gradually increased to obtain an anaerobic bottom plate bacterial community that can tolerate salinity exceeding 3.0%.

[0038] As a preferred improvement of the present invention, highly salt-tolerant protease-producing bacteria are separated and screened from salt-tolerant anaerobic bottom bacterial flora. The separation and screening process includes: separation and purification in 4.0% salinity peptone solid culture medium, primary screening of protease production capacity at 4.0% salinity, and secondary screening of salt tolerance at 8.0% salinity.

[0039] On the other hand, according to the above screening method, the present invention screened and provided a highly salt-tolerant, protease-producing protactin-producing Arthrobacterium glabratum A1, whose preservation number is CCTCC NO: M 20241041, the preservation time is May 23, 2024, and the preservation location is China Center for Type Culture Collection.

[0040] As a preferred improvement of the present invention, the 16S rDNA of the original Arthrobacter glabraeni has a nucleotide sequence as shown in SEQ ID NO.1.

[0041] As a preferred improvement of the present invention, the salt tolerance of the original Arthrobacter glabraensis under anaerobic conditions can reach more than 4.0%, even more than 6.0%, even up to 8.0%, and secrete protease.

[0042] The present invention also provides an application of the original glass fly Arthrobacter in the anaerobic fermentation of kitchen wastewater to produce organic acids. After the original glass fly Arthrobacter A1 is activated and cultured, it is compounded with anaerobic acid-producing activated sludge bacterial liquid as an inoculum (volume ratio 1:10); and organic acids are produced by fermentation with kitchen wastewater as raw material at pH 7.0 and 36°C.

[0043] The present invention is further explained below with specific examples. However, it is easy for those skilled in the art to understand that the specific process conditions and results described in the examples are only used to illustrate the present invention, and should not and will not limit the present invention described in detail in the claims.

[0044] Example:

[0045] The high salt-tolerant protease producing bacteria separation and fermentation medium involved in the following embodiments are as follows:

[0046] ①4.0% salinity peptone solid medium: 10.0 g / L tryptone, 20.0 g / L agar, 40 g / L sodium chloride, 0.2 g / L magnesium sulfate heptahydrate, 1.0 g / L potassium dihydrogen phosphate, 1.5 g / L potassium hydrogen phosphate, 0.25 g / L L-cysteine ​​hydrochloride monohydrate. In addition, 1.0 mL of vitamin solution and 1.0 mL of trace element solution are added to the unit volume (L) of the solution to adjust the pH to 7.0.

[0047] ②4.0% salinity clear zone medium: casein 16.0g / L, sucrose 30.0g / L, agar 20.0g / L, sodium chloride 40g / L, disodium hydrogen phosphate 1.0g / L, magnesium sulfate heptahydrate 0.5g / L, sodium nitrate 2.0g / L, ferrous sulfate 0.01g / L. Adjust the pH to 7.0.

[0048] ③4.0% salinity gelatin liquefaction medium: beef extract 3.0g / L, gelatin 200.0g / L, trypsin 5.0g / L, sodium chloride 40g / L, adjust the pH to 7.0.

[0049] ④LB medium: 10.0 g / L tryptone, 5.0 g / L yeast extract, 10.0 g / L sodium chloride, adjust the pH to 7.0.

[0050] ⑤ Salt-tolerant rescreening medium: 10 g / L tryptone, 80 g / L sodium chloride, 0.2 g / L magnesium sulfate heptahydrate, 1.0 g / L potassium dihydrogen phosphate, 1.5 g / L potassium hydrogen phosphate, 0.25 g / L L-cysteine ​​hydrochloride monohydrate. In addition, 1.0 mL vitamin solution and 1.0 mL trace element solution are added to the unit volume (L) of the solution to adjust the pH to 7.0.

[0051] ⑥Basic fermentation medium: 6.5 g / L tryptone, 0.2 g / L magnesium sulfate heptahydrate, 1.0 g / L potassium dihydrogen phosphate, 1.5 g / L potassium hydrogen phosphate, 0.25 g / L L-cysteine ​​hydrochloride monohydrate. In addition, 1 mL of vitamin solution and 1 mL of trace element solution are added to the unit volume (L) of solution, and sodium chloride is added in different proportions to adjust the pH to 7.0.

[0052] Example 1 Construction of salt-tolerant anaerobic tray flora

[0053] This embodiment adopts the adaptive evolution strategy of microbial flora to construct a salt-tolerant protein-degrading chassis flora. The adaptive evolution is carried out in a fully mixed anaerobic reactor, using a continuous flow fermentation mode, and the inoculum is anaerobic methanogenic activated sludge. The components of the reactor influent are shown in Table 1, with peptone as the only carbon and nitrogen source, the initial inoculation sludge concentration is 33.0g-TS / L, the stirring speed is 100rpm, the fermentation temperature is 36°C, and the pH is controlled at 7.0. The initial influent salinity is 1.5%, and the hydraulic retention time is 10 days.

[0054] Table 1 Influent components of adaptive evolution reactor

[0055]

[0056] (1) Changes in COD removal rate during adaptive evolution

[0057] In the process of salt stress adaptive evolution, COD removal rate was used to characterize the change of salt tolerance of anaerobic bacteria. On the basis of COD removal rate higher than 70% in steady state, the salinity of reactor inlet water was increased gradually, and the anaerobic bacteria were adaptively evolved to salt tolerance, so as to obtain anaerobic bottom plate bacteria that could tolerate salinity higher than 3.0%.

[0058] like Figure 2 As shown, the inoculated anaerobic methanogenic sludge was able to quickly adapt to 1.5% (1-6d) and 2.0% (7-14d) salt stress, with the effluent COD between 1280-1920 mg / L and the COD removal rate maintained above 80%.

[0059] When the influent salinity was increased to 2.6% (15-21d), the removal rate dropped to 64.0% and then quickly recovered to 77.6%.

[0060] When the influent salinity was further increased to 2.9% (22-51d), under this stress, COD removal first decreased to 58.1%, and then gradually recovered to 72.3%, but the tolerance response time was significantly prolonged.

[0061] When the salinity was further increased to 3.2% (52nd-61st day), the effluent COD concentration did not change significantly, and the COD removal rate remained stable between 74.4% and 84.0%.

[0062] This shows that salt-tolerant microorganisms have become dominant through salinity gradient domestication. However, when the salinity increased to 3.6% (62-116d), the COD removal rate gradually decreased to about 55.0% and was difficult to recover. Therefore, the "top-down" adaptive evolution strategy of anaerobic flora can preliminarily construct an anaerobic chassis flora that tolerates 3.2% salinity.

[0063] (2) Changes in protein degradation rate during adaptive evolution

[0064] Protein degradation rate of anaerobic bacteria during adaptive evolution Figure 3 As shown, under 1.5% low salt stress, the average protein degradation rate can reach 93.2%.

[0065] With the increase of the influent salinity gradient and the gradual adaptation of the anaerobic bacteria to the salt stress, protein degradation first decreased and then gradually recovered. Finally, under 3.2% salt stress, the protein degradation rate recovered to about 90%.

[0066] However, when the inlet salinity was further increased to 3.6%, the effluent protein concentration increased significantly, and the protein degradation rate decreased to about 71.2%, which was difficult to recover.

[0067] This indicates that the anaerobic bacteria have insufficient protease secretion capacity under this salt stress and protein hydrolysis is inhibited. Therefore, this example uses the salt-tolerant adaptive evolution sludge obtained under 3.2% salt stress as a source to screen high salt-tolerant protease producing bacteria.

[0068] Example 2 Directed screening of highly salt-tolerant protease producing bacteria

[0069] (1) Isolation and purification of protease-producing bacteria and initial screening of enzyme production capacity

[0070] Although the "top-down" adaptive evolution strategy can initially construct a salt-tolerant chassis bacterial community that tolerates 3.2% salinity, under higher salt stress, insufficient protease secretion leads to inhibition of protein hydrolysis. Therefore, in order to increase the protease production performance under high salt stress, salt-tolerant enzyme-producing microorganisms were screened from the salt-tolerant chassis bacterial community.

[0071] The separation and screening process includes: taking the salt-tolerant adaptive evolution sludge obtained under 3.2% salt stress as a sample, placing the anaerobic bacterial community in an anaerobic tube and adding glass beads, oscillating and dispersing, and then gradient dilution using physiological saline. Then the diluted bacterial suspension is spread on a 4.0% salinity peptone solid culture medium plate and inverted in a 36°C anaerobic constant temperature incubator for 48 hours. The plate streak separation method is continued to purify the grown single colonies, and then the isolated and purified strains are stored on a 4.0% salinity solid slant culture medium.

[0072] A total of 16 strains (named A1-A16) were isolated and purified at 4.0% salinity. The isolated and purified strains were inoculated into 4.0% salinity transparent zone medium and 4.0% salinity gelatin liquefaction medium by three-point method and puncture inoculation method, respectively. The ratio of transparent zone diameter to colony diameter (>1.5) and gelatin liquefaction degree were used as evaluation criteria to screen out salt-tolerant strains with strong protease production ability. As shown in Table 2, strains with 1.5 < transparent zone diameter / colony diameter <2 accounted for 56.25%. Nine strains (A1, A2, A3, A4, A5, A7, A8, A10, A13) with ratio >1.5 and high gelatin liquefaction degree were selected for further analysis of their salt tolerance.

[0073] Table 2 Preliminary screening of enzyme production capacity of protease producing bacteria

[0074]

[0075]

[0076] (2) Rescreening of salt tolerance of protease-producing bacteria

[0077] The protease-producing bacteria screened were subjected to salt tolerance rescreening. The specific process included: after the screened strains were cultured in LB liquid medium for 48 hours, the diluted bacterial suspensions were respectively applied to 8.0% salt tolerance rescreening solid medium, and then the protease-producing bacteria that could tolerate 8.0% salinity were screened (such as Figure 4 shown).

[0078] like Figure 5 As shown in the figure, after 48 h of batch fermentation in 8.0% salt-tolerant medium, the biomass of the fermentation broth of strain A1 was significantly higher than that of other strains, and the OD 600 Reached 0.95. Therefore, strain A1 has better salt tolerance.

[0079] (3) Identification of bacterial species

[0080] The 16S rDNA sequence of strain A1 obtained by screening with bacterial universal primer amplification was sent to Shanghai Sangon Biotechnology Co., Ltd. for sequencing. Its 16S rDNA sequence is shown in SEQ ID NO.01, and the strain sequence length is 1437bp. The 16S rDNA sequence was compared on GenBank. The results showed that its 16S rDNA sequence similarity with that of Arthrobacter protophormiae (GenBank Number: GQ395612.1) was as high as 99.72%. Therefore, the highly salt-tolerant protease-producing strain was identified as Arthrobacter protophormiae, and was deposited in the China Center for Type Culture Collection on May 23, 2024. Its deposit number is CCTCCNO: M 20241041, and it is named Arthrobacter protophormiae A1. Example 3 Salt tolerance of Arthrobacter protophormiae A1

[0081] (1) Effect of salinity on the growth of Arthrobacterium truncatum A1

[0082] The original glass fly Arthrobacter A1 was transferred to the basic medium for batch fermentation to investigate the effects of salt stress on its growth, protease secretion and protein degradation. The growth curves under different salinities (2.0%, 4.0%, 6.0%, 8.0%) are shown in Figure 2. Figure 6 As shown, it can grow under salinity conditions of 2.0%-8.0%. When the salinity reaches 4.0%, 6.0% and 8.0%, the strain has the highest biomass (measured in OD 600 ) were 1.68, 1.32 and 0.99, respectively, compared with 2.0% salinity (maximum OD 600 1.76) were reduced by 4.5%, 25.0% and 43.7% respectively. Correspondingly, it can be concluded that at 4.0%, 6.0% and 8.0% high salinity, the maximum biomass retention rates reached 95.5%, 75.0% and 56.3% respectively. It can be seen that the original glass fly arthrobacter A1 has a high salt tolerance. Although high salinity has a certain inhibitory effect on its growth efficiency, it can still maintain more than half of the maximum biomass at a high salinity of 8.0%.

[0083] (2) Effect of salinity on protease secretion by Arthrobacterium truncatum A1

[0084] Effects of salinity on the secretion of protease from Arthrobacterium glabrata A1 Figure 7As shown, the protease activity in the fermentation broth under different salt stresses reached the maximum value during the stable growth period of bacteria (the second day). At 2.0%, 4.0%, 6.0% and 8.0% salinity, the maximum enzyme activity was 55.2U / mL, 52.6U / mL, 35.9U / mL and 25.5U / mL, respectively. It can be concluded that when the salinity reached 4.0%, 6.0% and 8.0%, the enzyme activity remained at 95.3%, 65.0% and 46.2% compared with the salinity of 2.0%. This shows that the original glass fly arthrobacter A1 can still grow effectively and secrete proteases under high salt stress.

[0085] (3) Effect of salinity on protein degradation by Arthrobacterium truncatum A1

[0086] Effects of salinity on protein degradation by Arthrobacterium glabrata A1 Figure 8 As shown in the figure, at 2.0%, 4.0%, 6.0% and 8.0% salinity, after 3 days of anaerobic batch fermentation, the protein degradation rates reached 61.1%, 55.1%, 48.9% and 41.4%, respectively. This shows that Arthrobacter spp. A1 can effectively hydrolyze proteins under high salt stress.

[0087] Example 4 Application of Arthrobacterium glabratum A1 in anaerobic acid production from actual restaurant wastewater

[0088] The restaurant wastewater in this embodiment comes from high-concentration organic wastewater generated after sorting, crushing and three-phase separation pretreatment in a centralized restaurant waste treatment plant.

[0089] The COD concentration and salinity of the wastewater were as high as 109.7 g / L and 1.7%, respectively, and the crude protein and total sugar concentrations were 24.9 g / L and 28.3 g / L, respectively. In this embodiment, the original glass fly arthrobacter A1 was activated and cultured in LB medium, and then compounded with anaerobic acidogenic activated sludge as an inoculum (volume ratio 1:10), and anaerobic acidogenesis of kitchen wastewater was carried out in a 5L fermenter, and the pH and temperature were controlled at 7.0 and 36.0°C, respectively. The fermenter inoculated only with anaerobic acidogenic sludge was used as a control.

[0090] The results are as follows Fig. 9 As shown, after 21 days of anaerobic fermentation, the final production of organic acids in the bacteria-added group was 55.1 g / L, which was significantly increased by 38.8% compared with the control group.

[0091] Along with the production of organic acids, in order to avoid the decrease in pH caused by acid production and the weakening of microbial metabolic activity, it is necessary to add alkali solution to maintain the pH stability of the entire fermentation process. However, the addition of alkali solution will gradually increase the salinity of the fermentation system. The highest salinity during the fermentation of the bacteria-added group and the control group reached 3.9% and 3.3%, respectively. In a high-salt environment, the total sugar degradation rate of the control group was 87.9%, while the protein degradation rate was only 56.7%. In contrast, the original glass fly arthrobacter A1 significantly enhanced protein conversion. Even in a higher salinity environment, the total sugar and protein degradation rates of the bacteria-added group reached 95.3% and 92.8%, respectively. It can be seen that the original glass fly arthrobacter A1 can effectively enhance the anaerobic treatment effect of high-salt and high-protein wastewater such as kitchen wastewater.

[0092] 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. A highly salt-tolerant protease-producing Arthrobacterium glabratum, characterized in that: The ArthrobacterprotophormiaeA1 was deposited in the China Center for Type Culture Collection on May 23, 2024, with the deposit number being CCTCC NO: M 20241041.

2. The Arthrobacterium protothecoides according to claim 1, characterized in that: The original glass fly Arthrobacterium can secrete protease under anaerobic conditions and has a salt tolerance of more than 4.0%; Preferably, the maximum salt tolerance is 8.0%; Preferably, the salinity tolerance is 4.0%-8.0%.

3. The Arthrobacterium protothecoides according to claim 2, characterized in that: The enzymatic activity of the protease reaches 25U / mL or more; Preferably, when the salinity is 4.0%-6.0%, the activity of the protease reaches above 35U / mL; Preferably, when the salinity is 6.0%-8.0%, the activity of the protease reaches above 25 U / mL.

4. Use of the Arthrobacterium protohyalii according to any one of claims 1 to 3 in wastewater treatment, wherein the wastewater treatment comprises anaerobic fermentation of kitchen wastewater to produce organic acids.

5. An anaerobic fermentation inoculant of kitchen wastewater, characterized in that: The invention comprises anaerobic acid-producing activated sludge and the highly salt-tolerant protease-producing Arthrobacterium glabratum as described in claims 1-3.

6. The anaerobic fermentation inoculant of kitchen wastewater according to claim 5, characterized in that: The volume ratio of the activated liquid of Arthrobacter glabratus to the bacterial liquid of the anaerobic acidogenic activated sludge is 1:5-1:15, preferably 1:

10.

7. A method for producing organic acids by anaerobic fermentation of kitchen wastewater, characterized in that: Anaerobic fermentation inoculum of kitchen wastewater is added to the kitchen wastewater, and fermented for 18-25 days at pH 6.5-7.5 and 30-40° C. The anaerobic fermentation inoculum of kitchen wastewater is the anaerobic fermentation inoculum of kitchen wastewater as claimed in claim 5 or 6.

8. The method according to claim 7, characterized in that: The initial salinity of the kitchen wastewater reaches more than 1.5%, and the highest salinity during the fermentation process reaches more than 3.5%.

9. The method according to claim 7, characterized in that: The protein degradation rate of the kitchen wastewater is above 70%; Preferably, the protein degradation rate of the kitchen wastewater is above 80%, and the total sugar degradation rate is above 90%; Preferably, the protein degradation rate of the kitchen wastewater is above 90%, and the total sugar degradation rate is above 95%.

10. The method according to claim 7, characterized in that: The organic acid yield reaches more than 50g / L.

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