System for producing glutaric acid through whole-cell catalysis and application of system

Abstract

The invention relates to the technical field of bioengineering, in particular to a system for producing glutaric acid through whole-cell catalysis and application of the system. According to the system provided by the invention, L-lysine is taken as a substrate, halomonas is utilized, 5-aminovaleric acid is firstly synthesized, and then 5-aminovaleric acid transaminase and glutamate semialdehyde dehydrogenase expressed by the halomonas are further utilized to finally form glutaric acid. The halomonas can be used as zymocyte for open type fermentation without additional sterilization, and meanwhile, various air filter membranes and complex sterile operation are not needed in the fermentation process to reduce the possibility of contamination, so that the production cost and manpower and material resources are greatly saved; in addition, the yield and the yield of glutaric acid synthesized by taking L-lysine as a substrate are higher than those of glutaric acid synthesized by a conventional method.

Description

Technical Field

[0001] The present invention relates to the field of bioengineering technology, and in particular to a system for producing glutaric acid by whole-cell catalysis and application thereof. Background Art

[0002] Glutaric acid, with the molecular formula HOOC(CH2)3COOH, is an important organic chemical raw material and intermediate. It can be used to produce commercial polyesters and polyamides, and is also used to make dimethyl glutarate and diethyl glutarate. Traditional industries mainly obtain glutaric acid through petrochemical routes, for example: using cyclohexanone to produce adipic acid by nitric acid oxidation, and glutaric acid can be recovered from the by-product; or glutaric acid can be obtained by liquid phase oxidation of cyclopentanone. These methods have problems such as high cost and non-renewable nature.

[0003] Existing research discloses a method for producing glutaric acid by microbial fermentation, which uses Corynebacterium glutamicum that can synthesize 5-aminovaleric acid, overexpresses 5-aminovaleric acid transaminase (GabT) and glutamate semialdehyde dehydrogenase (GabD) under the control of the constitutive tuf promoter, and further converts 5-aminovaleric acid into glutaric acid. The strain GTA-1 constructed by this method uses glutaric acid as the main product, but still secretes 5-aminovaleric acid. Therefore, the endogenous 5-aminovaleric acid internal transporter NCgl0464 is further overexpressed, and glutaric acid is formed from glucose at a yield of 0.27 mol / mol. In batch fermentation, GTA-4 produced more than 90 g / L of glutaric acid from glucose and molasses-based sugars, with a maximum yield of 0.70 mol / mol and a maximum yield of 1.8 g / L / h, while no longer secreting 5-aminovaleric acid (see A bio-based route to the carbon-5 chemical glutaric acid and to bionylon-6,5 using metabolically engineered Corynebacterium glutamicum.). However, this method requires strict sterilization, and the synthesis of glutaric acid using glucose as a substrate is a long route, with low conversion efficiency and the formation of multiple by-products.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] To solve the above technical problems, the present invention provides a system for producing glutaric acid based on L-lysine and whole-cell catalysis of Halomonas and its application, which provides a new idea for the production of glutaric acid.

[0006] Specifically, the technical solution of the present invention is as follows: In a first aspect, the present invention provides a whole-cell catalytic system for producing glutaric acid, including L-lysine and Halomonas that synthesizes 5-aminovaleric acid and simultaneously expresses 5-aminovaleric acid transaminase and glutamate semialdehyde dehydrogenase.

[0007] The whole-cell catalytic system for producing glutaric acid provided by the present invention uses L-lysine as a substrate, uses Halomonas, first synthesizes 5-aminovaleric acid, and then further uses 5-aminovaleric acid transaminase and glutamate semialdehyde dehydrogenase expressed by Halomonas to finally form glutaric acid. As a fermentation bacterium, Halomonas can perform open fermentation without additional sterilization. At the same time, various air filter membranes and complex aseptic operations are not required to reduce the possibility of bacterial contamination during the fermentation process, which greatly saves production costs and manpower and material resources; in addition, the yield and output of glutaric acid synthesized by the present invention using L-lysine as a substrate are higher than those of conventional methods.

[0008] Preferably, the amino acid sequence of the 5-aminovaleric acid transaminase is as shown in SEQ ID NO.01, SEQ ID NO.02, SEQ ID NO.03 or SEQ ID NO.04; preferably as shown in SEQ ID NO.01; And / or, the amino acid sequence of the glutamate semialdehyde dehydrogenase is shown as SEQ ID NO.05, SEQ ID NO.06, SEQ ID NO.07, SEQ ID NO.08 or SEQ ID NO.09; preferably as shown in SEQ ID NO.06.

[0009] Preferably, in the Halomonas, the nucleotide sequence used to express the 5-aminovaleric acid aminotransferase is as shown in SEQ ID NO.11, SEQ ID NO.12, SEQ ID NO.13 or SEQ ID NO.14; preferably as shown in SEQ ID NO.11; And / or, the nucleotide sequence used to express the glutamate semialdehyde dehydrogenase is shown as SEQ ID NO.15, SEQ ID NO.16, SEQ ID NO.17, SEQ ID NO.18 or SEQ ID NO.19; preferably as shown in SEQ ID NO.16.

[0010] The detailed information of each amino acid sequence is as follows: gabT1, SEQ ID NO.01: MKMSNAQLNELKQKYVANGAASPATQFADRAENAIIWDADGNRIIDFAGGIGVLNIGHCHPKVVEAVREQLGRVMHTCQTVIPYEGYVKVAEKLSQLTPVRGHAKVMLVNSGAEALENAVKVARAATGKNNVICFDGGYHGRTFMTMAMNGKVAPYSADFGSMPGNVFRAPYPVPFHGVSEEDALRGLKMTLKTDANPKDTAAIVIEPVLGEGGFYPAPASFLKAVREICDEHGMLMIVDEVQSGFGRTGKLFAIEHSGVQPDIITMAKSMAGGMPISALVGTAEHMDASGPNSLGGTYSGSPVSCAAVLAVLEVLEEEKILEKSQALGEVLGQRFTQWQQRFACVENVRHLGSMAALDIVSAGQEPDAELAAAMCKRAREKGLILLSCGLYGNTIRFLMPVTIEDSILEEGLAIVEALLEELTA。

[0011] gabT2,SEQ ID NO.02: MSNAELNELKQKYVAAGAASPATAFADRAENAEIWDADGNRFIDFAGGIGVLNVGHRHPKVVAAVKAQLDKVMHTCQTVMPYEGYVKVAEKLSHIVPVRGHAKVMLANSGAEALENAVKIARAATGRSNVICFDGGYHGRTFYTMAMNGKVAPYQTDFGPMPGTVFRAPYPVPYHGVSEDEAIRGLKMTLKTDANPKDTAAIVLEPVLGEGGFYPASKSFLEKIREICDEHGILMIIDEVQSGFGRTGKMFAIEHSGVEPDIMTMAKSMADGMPISAIVGTDKVMDASGPNSLGGTYTGSPTACAAALAVLEVFEEENILEKSQALGEKLAARFGEWQNKFDCIDHVRNMGAMAAFELVSNKTDRTPNAELAAALCKKAREEGLILLSCGMYGNTIRFLMPVTIEDSVLNEGLDIIESCLESLV。

[0012] gabT3,SEQ ID NO.03: MMNNQELNELKNRYVANGAATPTTQFAERAENAELWDADGNRWIDFAGGIGVLNLGHRHPKIVAAVEAQLKKVMHTSAAVISYAPYVQLCQKLCELTPVRGPERKAMLVNTGAEALENAVKIARAATGRTGIITFDGAFHGRTMMTLAMTGKVLPYKNDFGPMPGDVFRAPFPNPLHGISEEASLDAIRTLFKTDIAPHRTAAIVIEPVQGE GGFYIASPDYLKALRALCDEHGILLIADEVQSGFARTGKLFALEHSGIEADILTTAKSLANMPLSAVVGSAKVMDASGPNSLGGTYSGNPLSCAAALAVIEVIEEDILARSEQMGKMLAERFAVWEARFPAVAHGRQLGAMAAFELLNSEGKPDTALTGALCAKAREKGLILLSCGFYGNSIRILVPLTVSSAVLEEGLSIIEESLEALS。

[0013] gabT4, SEQ ID NO.04: MAISGAFTTMDLPYVSSALGILHPVCITKGRNAEVWDEAGQRYIDFIGIGGVLNLGHGHPAVVEAVKAQVDTLMHSAFNALPHRGYLSVVERLDQFVPVSYPLGCMLTNSGAEATENALKVARGVTGRQGVIAFDDAFHGRTLAALNLNGKVKPYKAGLGALPGPVYHVPPFSQDSGVSAEQSLAALERVFDVEIAPSEVACVVVEPIQGEGGFRLLCPQFAKALREICDQHGILLICDEIQSGFGRTGKRFGFSHLGIEPDLLLLGKSIASGLPLAALVGRKELMDALPKGALGGTYSGNAVACSAALAVMDIMQDDALSAWGDAQEAAIVSAYQRWKTSRFPMLGAMTGIGAMRGIVFEDTENATGAEHLANLLSAGRDAGVLLMPSGRKRNVLRLLPPLTTEADVMAEGLGLIEQALETLKA.

[0014] gabD1, SEQ ID NO.05: MQRFVAHDWLHRNWLQPGEVPMTTLSTTLTKRLEDPRLFRQYAYVDGKWTHGDGGREEAVYDPATNEAIGHIPLLEAEQITAAVDAAEAAFVQWRALRADERCERLLAWYDLIQANREDLATIMTLEQGKPLPDARGEVEYGASFVRWFAEEGKRTYGETIPSHIPNASLGTIKEPVGIAAMITPWNFPLAMITRKAAAALAAGCPVIIKPANETPFSALALAELAERAGIPEGIFNVVLGDPAEVSKILCSEPRIRALSFTGSTRVGRLLIEQSANTVKRLSLELGGNAPFIVGPDMDPKEAAYAAVSAKFQTAGQDCLAANRILVHESIHDEFVEQFTERMAALTVGNGLHGEVDLGPLIHRQAVEKAASIVDDAISKGATMIAGDQSQAPGENFFMPVLLTNVTPQMKVWREENFAPVAGITAYSTDDEVIEMANDTEYGLAAYIYTHDIRRIWKLMRALEYGMVSVNSVKMTGPPVPFGGVKQSGLGREGGATGIDEYLETKYYCLGALGSVSGS。

[0015] gabD2,SEQ ID NO.06: MSKLPDILIPDAFIGGEWCGAEKRFAVTNPANGELLAEVPDLDADGARAAVAAAEAAGPGWKKRTAKERATLLRAWFDAIMAHQEDLARLMTLEQGKPLAESRGEVAYGASFVEFYAEESKRMAGETLPGHGVDKRILVFREPIGVVAAVTPWNFPLAMITRKCAPALAAGCTVVIKPAEATPLTALAVARLAELAGLPAGVINVVTASQPAPIGEVLTTDPRVRKFSFTGSTPVGKKLLAQCAGTVKKVSLELGGNAPFIVFDDADLDAAVEGAVASKYRNSGQTCVCTNRFLVQSGVYDVFVEKLAKRVAQLNVGNGLDEGVMQGPLINQAAVEKVESHIADAMEKGGRLVCGGKPHTLGGTFFEPTIIADVTDNMRVAREETFGPLAPVFRFETDDEAIAMANATEFGLAAYFYARDYRRIWHVMEGLEYGMVAVNEGILSTELAPFGGVKESGLGREGSRHGLDEFTELKYVCVGGL.

[0016] gabD3, SEQ ID NO.07: MMSFIEKWLHDAVPTLVGGEWRKGQQTFAVDNPATGETIARVADLGADDARDAVAAAYAAGPAWRATPVKQRSALLRRWFDLINEHADDLARLMTLEQGKPLAEAKGEVTYGASFIEFFAEEAKRMAGETLPSHGADKRLLVLREPVGVVAAITPWNFPLAMITRKCAPALAAGCTVVIKPAEATPLTALATAYLALEAGLPAGTINVITASKPAAVGEVLTTDSRVRKVSFTGSTPVGKHLLAQCASTVKKTAMELGGNAPFIVFDDADVDAAVEGAIASKFRNAGQTCVCTNRFLVQDGVYDAFVSKLTERVSALKVGDGLTEGSTIGPLINQAAVEKVQRHVDDAVNHGARLLCGGKPHAAGERFFTPTVLADVTTQMAVADEETFGPVAPVFRFHRDEEAIAMANDTPFGLAAYFYATGYRRIWHTMEQLEYGMVGVNEGLISTELAPFGGVKESGLGREGSHHGLDEFTELKYVCVGGL。

[0017] gabD4,SEQ ID NO.08: MLKLKDATLQRDACLVGGSWISADDNQFDDVTNPADGSVLGRVPHLGEAETLRAIDAAEEALPAWQARSAKERGAMLRRWHDLLLEHQDDLAALMTAEQGKPLAEARGEIGFAASFFEWFAEEGRRTYGDVIPSPQSDRRLLVIKQPVGVCAAITPWNFPAAMIARKAGPALAAGCTIVIKPAGQTPYSALAMALLAQRAGIPDGVVNVVTGDARAIGRAMTESPKVRKLTFTGSTGVGKLLLRQCADSVKKVSMELGGNAPFIVFDDADLEKAIEGVMQAKFRNAGQTCVCANRIFVQAGIHDAFAARLAQEVAKLQVGDGAEEGVQVGPLIDAAAADKVMEQLNDAVAKGATLLQGGERRGANFLTPAVITGATPEMDCFNEETFGPLAPVFSFQDEAEVIRLANATEYGLAAYCYTRDLGRAWRLSEALDYGMVGINNGHVSTCEAPFGGVKQSGLGREGARQGIEDYLETKYINMAIE。

[0018] gabD5,SEQ ID NO.09: MEALKETQLYCPFAYIDGSWVAADSGEQINVLNPATGEPVGDMPRLGKVETERAIDAADAALPAWRALTAQERADLLLKWHDLMLEHKHDLALLMTYEQGKPVKEAEGEIVYAASFLRWFAEEARRVYGETIPAAKSNQRIVVTKQPVGVVGAITPWNFPAAMITRKAGAALAAGCTIVVKPASQTPFSATALAMLAERAGIPRGVFNVVPGSAADIAKALTQSPKVRKITFTGSTEVGRKLMAQAAEHVQKISLELGGNAPFIVFEDADLDAAVEGAMAAKFRNAGQTCVCTNRFLVQSSVINAFCEKLAVAMNSELYVGNGTEPNINIGPLIDSDAVKKVSEHVQDAVDNGAELLLGGHPHPLGGNFFTPTLISFATDKMKVAREETFGPLAAVFPFDEEETAIEMANDTEYGLASYFYSRDLGRVWRVADALEYGMVGINTGLISNAAAPFGGVKASGLGREGGHQGLEEYLETKYLCIDLG。

[0019] NCgl0464: SEQ ID NO.10 MTRYKPSFHDVQRRPIVVNQITKDSVPVLAVDEIQDDGTPRRIMLLNKYDAKQLSAACDRYLQEIFSATFAGVNTDLSPDDMAKLFGDE。

[0020] The specific information of each nucleotide sequence is as follows: gabT1, SEQ ID NO.11:

[0021] gabT2,SEQ ID NO.12:

[0022] gabT3,SEQ ID NO.13:

[0023] gabT4,SEQ ID NO.14:

[0024] gabD1,SEQ ID NO.15:

[0025] gabD2,SEQ ID NO.16:

[0026] gabD3,SEQ ID NO.17:

[0027] gabD4,SEQ ID NO.18:

[0028] gabD5,SEQ ID NO.19:

[0029] The present invention found 4 endogenous 5-aminovaleric acid transaminase (amino acid sequence as shown in SEQ ID NO.01-04) and 5 endogenous glutamate semialdehyde dehydrogenase (amino acid sequence as shown in SEQ ID NO.05-09) in Halomonas. The present invention preferably uses endogenous 5-aminovaleric acid transaminase and glutamate semialdehyde dehydrogenase, which has a better effect. Among them, the 5-aminovaleric acid transaminase with an amino acid sequence of SEQ ID NO.01 and the glutamate semialdehyde dehydrogenase with an amino acid sequence of SEQ ID NO.06 have the highest expression levels.

[0030] Preferably, the promoter used for expressing 5-aminovalerate aminotransferase gabT and / or glutamate semialdehyde dehydrogenase gabD is selected from porin221, porin278, porin68, porin42 or porin58.

[0031] In one of the more specific embodiments provided by the present invention, the Halomonas contains the following normally expressed recombinant expression unit: pSEA321-Pporin 42-gabT1-gabD2.

[0032] Optionally, in the recombinant expression unit, Pporin 42 can also be replaced by porin221, porin278, porin68 or porin58.

[0033] Optionally, in the recombinant expression unit, gabT1 may also be replaced by gabT2, gabT3 or gabT4.

[0034] Optionally, in the recombinant expression unit, gabD2 may also be replaced by gabD1, gabD3, gabD4 or gabD5.

[0035] Preferably, in the present invention, the Halomonas overexpresses 5-aminovaleric acid internalization protein. Overexpression of 5-aminovaleric acid internalization protein helps to improve the intracellular utilization of 5-aminovaleric acid, reduce the leakage of 5-aminovaleric acid, and increase the yield and output of glutaric acid.

[0036] In one of the more specific embodiments provided by the present invention, the 5-aminovaleric acid internalization protein is the 5-aminovaleric acid internalization protein NCgl0464, and the Halomonas contains the following recombinant expression unit that can be normally expressed: Pporin221-NCgl0464. (SEQ ID NO.10) Preferably, in the present invention, the Halomonas expresses L-lysine 2-monooxygenase (DavB) and δ-aminovaleramidase (DavA). L-lysine 2-monooxygenase and δ-aminovaleramidase can convert the substrate L-lysine into 5-aminovaleric acid in the cell.

[0037] In one of the more specific embodiments provided by the present invention, the Halomonas is Halomonas M that synthesizes 5-aminovaleric acid (Halomonas bluephagenesis M is a strain obtained by knocking out the GabT4 gene based on Halomonas bluephagenesis F; Halomonas bluephagenesis F has the function of synthesizing 5-aminovaleric acid, and GabT1 and GabT2 are knocked out, and the knockout method used is Crisper-Cas9. Reference: Promoter Engineering for Enhanced P(3HB-co-4HB) Production by Halomonasbluephagenesis. ACS Synth. Biol. 2018, 7, 8, 1897–1906).

[0038] Preferably, in the system of the present invention, the concentration of L-lysine is 5±3 g / L; and / or the cell stem seed concentration of Halomonas is 10 g / L-12 g / L.

[0039] The system provided by the present invention realizes the synthesis of glutaric acid by taking L-lysine as a substrate in Halomonas through whole-cell catalysis, and reduces the leakage of 5-aminovaleric acid by overexpressing 5-aminovaleric acid internalizing protein, thereby increasing the yield of glutaric acid.

[0040] In a second aspect, the present invention provides use of the system in preparing glutaric acid or downstream products containing glutaric acid.

[0041] In a third aspect, the present invention provides a method for preparing glutaric acid, which utilizes the aforementioned system, takes L-lysine as a substrate, and produces glutaric acid through whole-cell catalysis.

[0042] Preferably, the reaction temperature of whole-cell catalysis is 37±2°C, the stirring speed is 200±50rpm, the pH value is 7-8.5, and the reaction time is 48-72h.

[0043] The preparation method provided by the invention has the advantages of simple production process, low cost and broad application prospect.

[0044] Beneficial effects: The present invention provides a system for whole-cell catalytic production of glutaric acid and its application, the system includes L-lysine, and also includes Halomonas that synthesizes 5-aminovaleric acid and simultaneously expresses 5-aminovaleric acid transaminase and glutamate semialdehyde dehydrogenase. The system provided by the present invention uses L-lysine as a substrate, and uses Halomonas to first synthesize 5-aminovaleric acid, and then further uses 5-aminovaleric acid transaminase and glutamate semialdehyde dehydrogenase expressed by Halomonas to finally form glutaric acid. As a fermentation bacterium, Halomonas can be open fermented without additional sterilization. At the same time, various air filter membranes and complex aseptic operations are not required during the fermentation process to reduce the possibility of bacterial contamination, which greatly saves production costs and manpower and material resources; in addition, the yield and output of the present invention using L-lysine as a substrate to synthesize glutaric acid are higher than those of conventional methods. DETAILED DESCRIPTION

[0045] The technical solutions provided by the present invention are described in detail below in conjunction with the examples, but they should not be understood as limiting the scope of protection of the present invention. Unless otherwise specified, the experimental methods used in the examples are conventional methods; the materials and reagents used can be obtained from commercial sources.

[0046] Example 1 This embodiment provides a whole-cell catalytic system for producing glutaric acid. The system uses L-lysine as a substrate and utilizes Halomonas to first synthesize 5-aminovaleric acid, and then further uses 5-aminovaleric acid transaminase and glutamate semialdehyde dehydrogenase expressed by Halomonas to finally form glutaric acid.

[0047] (1) The shake flask experiment was performed using MM 50 medium. The culture conditions for Halomonas were as follows: initially adding 5 g / L L-lysine, pH 8.5-9.0, 200 rpm, 37°C, culturing for 48 h, and detecting the content of glutaric acid by HPLC.

[0048] (2) Using transcriptome data, we identified the gabT1 and gabD2 genes with the highest expression levels and constructed a constitutive promoter commonly used in the laboratory to drive the expression of gabT1-gabD2. The promoters used were porin221, porin 278, porin68, porin42, and porin 58. Taking Halomonas M, which synthesizes 5-aminovaleric acid, as the starting strain, pSEA321-Pporin221-gabT1-gabD2, pSEA321-Pporin 278-gabT1-gabD2, pSEA321-Pporin 68-gabT1-gabD2, pSEA321-Pporin 42-gabT1-gabD2, and pSEA321-Pporin 58-gabT1-gabD2 were overexpressed respectively. After shake flask experiments, 5 g / L of L-lysine was added, and the fermentation was carried out at 200 rpm and 37°C for 48 h, the maximum glutaric acid levels of 0.7, 0.91, 1.1, 1.7, and 1.41 g / L were achieved.

[0049] (3) Overexpression of 5-aminovaleric acid internalization protein. The plasmid of the internalization protein was constructed as Pporin221-NCgl0464. Halomonas M (a strain that synthesizes 5-aminovaleric acid) was overexpressed with the initial addition of 5 g / L 5-aminovaleric acid. The culture conditions were 200 rpm, 37°C, and cultured for 48 h. This reduced the leakage of 5-aminovaleric acid and increased the production of glutaric acid to 3 g / L.

[0050] The above-described embodiments only express several implementation methods of the present invention, which are convenient for understanding the technical solution of the present invention in detail, but cannot be understood as limiting the scope of protection of the present invention. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the scope of protection of the present invention.

Claims

1. A system for whole-cell catalytic production of glutaric acid, characterized in that: Including L-lysine, also includes Halomonas that synthesizes 5-aminovaleric acid and simultaneously expresses 5-aminovaleric acid transaminase and glutamate semialdehyde dehydrogenase.

2. The system according to claim 1, characterized in that: The amino acid sequence of the 5-aminovaleric acid transaminase is shown in SEQ ID NO.01, SEQ ID NO.02, SEQ ID NO.03 or SEQ ID NO.04; preferably, it is shown in SEQ ID NO.01; And / or, the amino acid sequence of the glutamate semialdehyde dehydrogenase is shown as SEQ ID NO.05, SEQ ID NO.06, SEQ ID NO.07, SEQ ID NO.08 or SEQ ID NO.09; preferably as shown in SEQ ID NO.

06.

3. The system according to claim 1 or 2, characterized in that: In the Halomonas, the nucleotide sequence used to express the 5-aminovaleric acid transaminase is as shown in SEQ ID NO.11, SEQ ID NO.12, SEQ ID NO.13 or SEQ ID NO.14; preferably as shown in SEQ ID NO.11; And / or, the nucleotide sequence used to express the glutamate semialdehyde dehydrogenase is shown as SEQ ID NO.15, SEQ ID NO.16, SEQ ID NO.17, SEQ ID NO.18 or SEQ ID NO.19; preferably as shown in SEQ ID NO.

16.

4. The system according to any one of claims 1 to 3, characterized in that: The promoter used for expressing 5-aminovalerate aminotransferase and / or glutamate semialdehyde dehydrogenase is selected from porin221, porin278, porin68, porin42 or porin58.

5. The system according to any one of claims 1 to 4, characterized in that: The Halomonas overexpresses 5-aminovaleric acid endonuclease.

6. The system according to any one of claims 1 to 5, characterized in that: The Halomonas bacteria express L-lysine 2-monooxygenase and delta-aminovaleramidase.

7. The system according to any one of claims 1 to 6, characterized in that: The concentration of L-lysine is 5±3 g / L; and / or the cell amount of Halomonas is 10 g / L.

8. Use of the system according to any one of claims 1 to 7 in the preparation of glutaric acid or downstream products containing glutaric acid.

9. A method for preparing glutaric acid, characterized in that: Utilizing the system described in claims 1-7, L-lysine is used as a substrate to produce glutaric acid through whole-cell catalysis.

10. The preparation method according to claim 9, characterized in that: The reaction temperature of whole-cell catalysis is 37±2°C, the stirring speed is 200±50rpm, the pH value is 7-8.5, and the reaction time is 48-72h.