Improved method for extracting meilingmycin from nanchang streptomycete fermenting liquor

Abstract

The improved method for extracting melingmycin from Nanchang streptomycete fermented liquor is mainly formed from the following steps: pretreatment process of fermented liquor, liquid-solid separation process, extracting melingmycin from residual filtrate and recovering process, pretreatment process of filter cake (mycelium), further solvent leaching of mycelium and concentration process of leaching liquor and one-step extraction process of concentrated leaching liquor. The total recovery rate of melingmycin can be up to above 85%.

Description

technical field [0001] The invention relates to a method for extracting antibiotics from fermentation broth, in particular to a method for extracting meilingmycin from fermentation broth of Streptomyces nanchang. Background technique [0002] Meilingmycin is a sixteen-membered macrocyclic lactone compound, which was first prepared by Ouyang Liang from Jiangxi Agricultural University and others through the fermentation of Streptomyces Nanchang. It has strong acaricidal, insecticidal and anthelmintic effects, and its content is only 0.15μg / mL is 100% lethal to silkworm, and the LC90 to citrus rust tick and cotton spider mite are 0.24μg / mL and 0.14μg / mL, respectively. It is an agricultural and veterinary antibiotic with novel structure, high efficiency, broad spectrum, low toxicity and independent intellectual property rights (CN 92110534.7). It has the same core structure as the agricultural insecticide Avermectins (Avermectins) and veterinary insect...

AI Technical Summary

Problems solved by technology

There are many impurities in the fermented liquid after putting into the tank, and the fermented liquid becomes very viscous due to partial autolysis of mycelia, which brings great difficulties to the subsequent separation process

Not only the filtration efficiency is very low (it usually takes more than ten hours to tens of hours in press filtration fashion), but also serious emulsification will occur during solvent extraction, making it difficult to separate the water phase and solvent phase, resulting in difficulties in extraction operations, so China Patent CN92110534.7 It is inappropriate to use lye to adjust the pH=8.5-9.0 of the fermented liquid

[0005] 2. It is very difficult to separate the liquid and solid phases

[0006] 3. Improper treatment of filtrate

If the filtrate is directly discarded, it will inevitably cause unnecessary loss of Meilingmycin, and if the film concentration (filtrate), alcohol extraction, and concentration are used, the concentrated filtrate obtained is not only poor in quality (a large part of the yellow pigment remains in the filtrate). Concentrate), and the cost is too high, a little bit more harm than good

[0007] 4. The solvent extraction process of filter cake (mycelia) has low efficiency, large solvent consumption and high cost

The prior art uses the solvent ethyl acetate to extract, and its single-stage efficiency is low. At least three stages of extraction are required to meet the extraction requirements, resulting in high solvent consumption and low concentration of effective components. Pigment removal rate is low, further processing is required

[0010] 6. There is no specificity in the process of decolorizing ethyl acetate extract with activated carbon

In the prior art, activated carbon is used to decolorize the ethyl acetate extract in order to remove the yellow pigment in the extract. Because the adsorption of activated carbon is non-specific adsorption, the loss of the target product is relatively large, and the activated carbon cannot completely remove the pigment. Further treatment is required. It can be seen that the use of Activated carbon adsorption decolorization treatment is not a good method

[0011] 7. The ethyl acetate extract is further processed by the method of column elution, but because the method is slow, inefficient, and molecular sieves are expensive, it is difficult for large-scale industrial application

[0012] In the prior art, in order to purify the ethyl acetate extract and further remove the pigment, try to solve it by upper column separation and elution method, so at first the ethyl acetate extract after activated carbon decolorization is heated and concentrated (removing ethyl acetate) to obtain concentrated Then the concentrate was dissolved in dichloromethane, then separated by molecular sieve SephadexLH-20 on the column, petroleum ether-dichloromethane-methanol or dichloromethane-ether system elution, the collected eluate was heated and concentrated (removed Solvents such as above-mentioned dichloromethane) obtain still having yellow oily matter Meilingmycin crude product, visible separation effect is still unsatisfactory, and extraction total recovery only accounts for 65.3% of the total content of Meilingmycin in a jar, it can be seen that More than 1 / 3 of the effective components are lost (referring to the record of Example 4 and Table 6 on page 12 of CN 1070228A)

[0013] As can be seen from the above, the prior art not only has disadvantages such as poor pertinence, long process route, lower production efficiency and yield, but also is difficult to effectively remove because of the presence of a large amount of yellow pigment in the fermented liquid, the resulting product quality is not good ( a yellowish liquid crude product)