Method for removing mycophenolic acid (MPA) from alkaline MPA-containing antibiotic mycelial fermentation residue (AMFR)

Abstract

Method to remove mycophenolic acid (MPA) from an alkaline MPA-containing antibiotic mycelial fermentation residue (AMFR), includes: subjecting an alkaline MPA-containing AMFR to a heat treatment in pr

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the field of antibiotic mycelial fermentation residue (AMFR) treatment, and more specifically relates to a method for removing mycophenolic acid (MPA) from an alkaline MPA-containing AMFR. BACKGROUND

[0002] With the development of medical level, the types of antibiotics are becoming increasingly abundant. Mycophenolic acid (MPA) is an immunosuppressant mainly used to prevent and treat acute rejection of transplanted organs. During the production of MPA by biosynthesis, there is a poor extraction rate of MPA in a culture medium, resulting in more MPA residues in the antibiotic mycelial fermentation residue (AMFR). These residues, if not being well treated, may pollute the environment. According to relevant information, an annual output of MPA in China is about tens of millions of tons, resulting in MPA-containing AMFRs at a relatively large amount. These MPA-containing AMFRs are currently mainly disposed of by landfill.

[0003] MPA-containing AMFR is cement gray in appearance and has a moisture content of 30% to 40%. If there is no reasonable treatment method, not only the value of AMFR itself can be wasted, but also some pollutions may be caused to the ecological environment. In the past, a large amount of AMFR was processed and used as animal feed or feed additive. However, the AMFR is easy to cause drug resistance in animals, and has not passed the safety test, such that there are various potential safety hazards. As a result, the AMFR was included in the "Catalogue of Drugs Prohibited for Use in Feed and Animal Drinking Water" in 2002. In 2008, China included AMFR in the list of hazardous wastes, and the AMFR is strictly prohibited from being reused without harmless tteatment. Therefore, a reasonable method for the treatment of MPA-containing AMFR is suggested. This method can not only effectively deal with the solid wastes generated, but also relieve certain environmental pressure and improve the soil. At present, there are few researches on the removal process of MPA in MPA-containing AMFR.

[0004] In view of the problems and defects in the prior art, the method for removing MPA from an alkaline MPA-containing AMFR needs further improvement and development. SUMMARY

[0005] The present disclosure provides a method for removing MPA from an alkaline MPA- 05 24 containing AMFR, and the specific technical schemes are as follows:

[0006] The present disclosure provides a method for removing MPA from an alkaline MPA-containing AMFR, including: subjecting an alkaline MPA-containing AMFR to a heat treatment in presence of phosphoric acid or sulfuric acid

[0007] wherein the alkaline MPA-containing AMFR is mixed with deionized water at a mass ratio of 1:10 to 1:19 before the phosphoric acid or the sulfuric acid is added;

[0008] wherein 5 ml to 15 ml of the phosphoric acid or the sulfuric acid is added into per 1 g of the alkaline MPA-containing AMFR;

[0009] wherein the phosphoric acid or the sulfuric acid has a concentration of 5 mol / L to 15 mol / L;

[0010] wherein the heat treatment is conducted in a homogeneous reactor at 150°C to 250°C for 2 h to 5 h; and

[0011] wherein oscillation, ultrasonically-assisted extraction, and centrifugation are conducted with ethanol after the heat treatment is completed.

[0012] Further, the ethanol and the phosphoric acid or the sulfuric acid may be present at a volume ratio of (1-5):1.

[0013] Further, the ultrasonically-assisted extraction may be conducted for 30 min to 60 min.

[0014] Further, the centrifugation may be conducted at 4,000 rpm to 5,000 rpm for 5 min to 10 min.

[0015] Due to the adoption of the foregoing technical solutions, the present disclosure has the following beneficial effects:

[0016] 1. In the present disclosure, the mycelium is ruptured by adjusting a pH value, a temperature and other factors of the AMFR, such that the MPA in cells can be released to accelerate degradation. Compared with simple heat treatment methods, the method of the present disclosure has a better removal efficiency of MPA and shortens more treatment time.

[0017] 2. In the present disclosure, the absence of transition metals and other substances is beneficial to subsequent resource utilization of the alkaline MPA-containing AMFR.

[0018] 3. In the present disclosure, the sulfuric acid or phosphoric acid can replace a mycophenolate sodium in AMFR with MPA, and can also degrade the replaced MPA. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] The following clearly and completely describes the technical solutions in the embodiments of the present disclosure with reference to the embodiments of the present disclosure. Apparently, the described embodiments are merely a part rather than all of the embodiments of the present disclosure. All other embodiments obtained by a person of ordinary skill in the art based on the 05 24 embodiments of the present disclosure without creative efforts shall fall within the protection scope of the present disclosure.

[0020] The present disclosure provides a method for removing MPA from an alkaline MPA-containing AMFR, including: subjecting an alkaline MPA-containing AMFR to a heat treatment in presence of phosphoric acid or sulfuric acid. The method can quickly and effectively remove the MPA in the alkaline MPA-containing AMFR, and realize the harmless treatment of the alkaline MPA-containing AMFR. Combining sulfuric acid or phosphoric acid treatment with heat treatment allows the process of the present disclosure to have a higher removal efficiency and shorten the time further. The sulfuric acid or phosphoric acid can replace a mycophenolate sodium in AMFR with MPA, and can also degrade the replaced MPA.

[0021] In the present disclosure, the alkaline MPA-containing AMFR is mixed with deionized water at a mass ratio of 1:(10-19) before the phosphoric acid or the sulfuric acid is added. The alkaline MPA-containing AMFR is mixed with the deionized water to form an AMFR to be treated. A mixed solution prepared from the alkaline MPA-containing AMFR, the deionized water, and the phosphoric acid or the sulfuric acid is raised to a reaction temperature through the heat treatment in a homogeneous reactor. In the homogeneous reactor, the phosphoric acid or sulfuric acid replaces the mycophenolate sodium in the alkaline MPA-containing AMFR with MPA and degrades the replaced MPA at the reaction temperature.

[0022] 5 ml to 15 ml of the phosphoric acid or sulfuric acid is added into per 1 g of the alkaline MPA-containing AMFR. The phosphoric acid or sulfuric acid provides hydrogen ions. When an equal amount of the alkaline MPA-containing AMFR reaches a same removal efficiency, a dosage of phosphoric acid should be less than that of sulfuric acid. After many experiments and explorations, the MPA has a better removal effect when 5 ml to 15 ml of the phosphoric acid or sulfuric acid is added into per 1 g of the alkaline MPA-containing AMFR.

[0023] The heat treatment is conducted at 150°C to 250°C for 2 h to 5 h. When the temperature is too low (less than 150°C), the MPA shows an extremely poor removal efficiency, and the MPA cannot be degraded. When the temperature is too high (greater than 250°C), residual organic matters and other nutrients in the AMFR are carbonized, which is not conducive to subsequent resource utilization. Therefore, it is necessary to find a suitable method that can not only remove the residual MPA in the alkaline MPA-containing AMFR, but also retain the nutrients in AMFR to the greatest extent.

[0024] The oscillation, ultrasonically-assisted extraction, and centrifugation are conducted with ethanol on an obtained mixed solution after the heat treatment is completed. The ethanol and the phosphoric acid or sulfuric acid are at a volume ratio of (1-5): 1; the ultrasonically-assisted 05 24 extraction is conducted for 30 min to 60 min; and the centrifugation is conducted at 4,000 rpm to 5,000 rpm for 5 min to 10 min. Specifically, the mixed solution is placed in a centrifuge tube, added with the ethanol, vortexed on a vortex mixer for 30 s, subjected to the ultrasonically-assisted extraction, followed by the centrifugation in a centrifuge. A resulting supernatant is transferred to another centrifuge tube, and the above operations are repeated 2 times.

[0025] Example 1

[0026] (1) 1 g of an alkaline MPA-containing AMFR was mixed evenly with deionized water at a ratio of 1:10 to obtain an AMFR to be treated;

[0027] (2) 10 mL of 10 mol / L phosphoric acid was added to the AMFR to be treated obtained in step (1) and stirred evenly;

[0028] (3) an obtained AMFR-containing mixed solution obtained in step (2) was treated in a homogeneous reactor at 180°C for 5 h; and

[0029] (4) a treated mixed solution obtained in step (3) was placed in a centrifuge tube, added with 20 mL of ethanol, vortexed on a vortex mixer for 30 s, subjected to ultrasonically-assisted extraction for 30 min, followed by centrifugation in a centrifuge at 4,000 rpm for 5 min. A resulting supernatant was transferred to another centrifuge tube, and the above operations were repeated 2 times.

[0030] Example 2

[0031] (1) 1 g of an alkaline MPA-containing AMFR was mixed evenly with deionized water at a ratio of 1:15 to obtain an AMFR to be treated;

[0032] (2) 5 mL of 15 mol / L phosphoric acid was added to the AMFR to be treated obtained in step (1) and stirred evenly;

[0033] (3) an obtained AMFR-containing mixed solution obtained in step (2) was treated in a homogeneous reactor at 250°C for 4 h; and

[0034] (4) a treated mixed solution obtained in step (3) was placed in a centrifuge tube, added with 15 mL of ethanol, vortexed on a vortex mixer for 30 s, subjected to ultrasonically-assisted extraction for 40 min, followed by centrifugation in a centrifuge at 4,500 rpm for 8 min. A resulting supernatant was transferred to another centrifuge tube, and the above operations were repeated 2 times.

[0035] Example3

[0036] (1) 1 g of an alkaline MPA-containing AMFR was mixed evenly with deionized water at a ratio of 1:19 to obtain an AMFR to be treated;

[0037] (2) 10 mL of 5 mol / L sulfuric acid was added to the AMFR to be treated obtained in step (1) and stirred evenly; 05 24

[0038] (3) an obtained AMFR-containing mixed solution obtained in step (2) was treated in a homogeneous reactor at 150°C for 2 h; and

[0039] (4) a treated mixed solution obtained in step (3) was placed in a centrifuge tube, added with 45 mL of ethanol, vortexed on a vortex mixer for 30 s, subjected to ultrasonically-assisted extraction for 60 min, followed by centrifugation in a centrifuge at 5,000 rpm for 10 min. A resulting supernatant was transferred to another centrifuge tube, and the above operations were repeated 2 times.

[0040] Example 4

[0041] (1) 1 g of an alkaline MPA-containing AMFR was mixed evenly with deionized water at a ratio of 1:10 to obtain an AMFR to be treated;

[0042] (2) 15 mL of 10 mol / L sulfuric acid was added to the AMFR to be treated obtained in step (1) and stirred evenly;

[0043] (3) an obtained AMFR-containing mixed solution obtained in step (2) was treated in a homogeneous reactor at 180°C for 1 h; and

[0044] (4) a treated mixed solution obtained in step (3) was placed in a centrifuge tube, added with 20 mL of ethanol, vortexed on a vortex mixer for 30 s, subjected to ultrasonically-assisted extraction for 30 min, followed by centrifugation in a centrifuge at 4,000 rpm for 10 min. A resulting supernatant was transferred to another centrifuge tube, and the above operations were repeated 2 times.

[0045] Examples

[0046] (1) 1 g of an alkaline MPA-containing AMFR was mixed evenly with deionized water at a ratio of 1:10 to obtain an AMFR to be treated;

[0047] (2) 15 mL of 5 mol / L phosphoric acid was added to the AMFR to be treated obtained in step (1) and stirred evenly;

[0048] (3) an obtained AMFR-containing mixed solution obtained in step (2) was treated in a homogeneous reactor at 150°C for 2 h; and

[0049] (4) a treated mixed solution obtained in step (3) was placed in a centrifuge tube, added with 20 mL of ethanol, vortexed on a vortex mixer for 30 s, subjected to ultrasonically-assisted extraction for 30 min, followed by centrifugation in a centrifuge at 4,000 rpm for 10 min. A resulting supernatant was transferred to another centrifuge tube, and the above operations were repeated 2 times.

[0050] Example 6

[0051] (1) 1 g of an alkaline MPA-containing AMFR was mixed evenly with deionized water at a ratio of 1:10 to obtain an AMFR to be treated; 05 24

[0052] (2) 10 mL of 5 mol / L sulfuric acid was added to the AMFR to be treated obtained in step (1) and stirred evenly;

[0053] (3) an obtained AMFR-containing mixed solution obtained in step (2) was treated in a homogeneous reactor at 150°C for 3 h; and

[0054] (4) a treated mixed solution obtained in step (3) was placed in a centrifuge tube, added with 20 mL of ethanol, vortexed on a vortex mixer for 30 s, subjected to ultrasonically-assisted extraction for 30 min, followed by centrifugation in a centrifuge at 4,000 rpm for 5 min. A resulting supernatant was transferred to another centrifuge tube, and the above operations were repeated 2 times.

[0055] Comparative Example 1

[0056] This comparative example differed from Example 4 in that no sulfuric acid was added, while other steps were exactly the same.

[0057] Comparative Example 2

[0058] This comparative example differed from Example 2 in that the reaction was conducted at 120°C in step (2).

[0059] Comparative Example 3

[0060] This comparative example differed from Example 6 in that 4 mL of the sulfuric acid was added in step (1).

[0061] The removal efficiency of MPA in Examples 1 to 6 and Comparative Examples 1 to 3 was determined. The MPA content was detected by high-performance liquid chromatography (HPLC). Test results were shown in Table 1.

[0062] Alkaline MPA-containing AMFR had an MPA content of about 15,000 mg / kg; the content of MPA after the experimental treatment was recorded as A mg / L. The removal efficiency was calculated by the following formula. A * V Removal efficiency = 1--—— 15000

[0063]

[0064] A: mass concentration, mg / L;

[0065] V: total volume of the solution added, mL;

[0066] m: mass of AMFR added, g.

[0067] Table 1 Removal efficiency of MPA in Examples 1 to 6 and Comparative Examples 1 to 3

[0068] Specific Examples Removal rate (%) Example 1 100% Example 2 100% Example 3 82.8% Example 4 90.1% Example 5 87.9% Example 6 80.79% Comparative Example 1 62.76% Comparative Example 2 35% Comparative Example 3 59.76% 05 24

[0069] It can be seen from the above table that the amount of phosphoric acid or sulfuric acid added and the heat treatment temperature had a great influence on the removal efficiency of MPA in the alkaline MPA-containing AMFR. Specifically, it was seen from the comparison between Example 4 and Comparative Example 1 that the removal efficiency of Example 4 reached 90.1%, while that of Comparative Example 1 was only 62.76%. This indicated that only heat treatment without adding sulfuric acid or phosphoric acid showed a poor removal efficiency. In addition, the higher the heat treatment temperature and the longer the treatment time were, the better the removal effect was. Under other conditions being the same, the removal effect of adding phosphoric acid was better than that of adding sulfuric acid. In the present disclosure, the mycelium is ruptured by adjusting a pH value, a temperature and other factors of the AMFR, such that the MPA in cells can be released to accelerate degradation. The method can effectively degrade the residue of MPA in the alkaline MPA-containing AMFR without introducing transition metals and the like.

[0070] It should be understood that although this specification is described in accordance with the embodiments, not every embodiment includes only an independent technical solution. Such a description is merely for the sake of clarity, and those skilled in the art should take the specification as a whole. The technical solutions in the embodiments can also be appropriately combined to form other implementations which are comprehensible for those skilled in the art.

Claims

05 241. A method for removing mycophenolic acid (MPA) from an alkaline MPA-containing antibiotic mycelial fermentation residue (AMFR), comprising: subjecting an alkaline MPA-containing AMFR to a heat treatment in presence of phosphoric acid or sulfuric acid;wherein the alkaline MPA-containing AMFR is mixed with deionized water at a mass ratio of 1: 10 to 1:19 before the phosphoric acid or the sulfuric acid is added;wherein 5 ml to 15 ml of the phosphoric acid or the sulfuric acid is added into per 1 g of the alkaline MPA-containing AMFR;wherein the phosphoric acid or the sulfuric acid has a concentration of 5 mol / L to 15 mol / L;wherein the heat treatment is conducted in a homogeneous reactor at 150°C to 250°C for 2 h to 5 h;wherein oscillation, ultrasonically-assisted extraction, and centrifugation are conducted with ethanol after the heat treatment is completed.

2. The method for removing MPA from an alkaline MPA-containing AMFR according to claim 1, wherein the ethanol and the phosphoric acid or the sulfuric acid are at a volume ratio of (1-5):1.

3. The method for removing MPA from an alkaline MPA-containing AMFR according to claim 1, wherein the ultrasonically-assisted extraction is conducted for 30 min to 60 min.

4. The method for removing MPA from an alkaline MPA-containing AMFR according to claim 1, wherein the centrifugation is conducted at 4,000 rpm to 5,000 rpm for 5 min to 10 min.