Lachnum and method for preparing melanin by liquid fermentation thereof

Abstract

The invention discloses a lachnum and a method for preparing a melanin by liquid fermentation thereof, and is characterized in that seed liquid which is obtained by the shaking culture after the Lachnum CCTCC M 209193 is activated is inoculated into a fermentation medium to conduct liquid fermentation according to 4-8 percent of the fermentation medium in volume; after the fermentation liquid is extracted with alkaline solution, a precipitation agent is used for precipitation; by the acid hydrolysis of hydrochloric acid, a crude melanin is obtained from a crude extract; then the crude melaninis re-dissolved in ammonia solution; and finally a pure melanin is obtained by using oil ether, chloroform and ethyl acetate for extraction in sequence. Compared with the method which adopts a basic fermentation medium, by adopting the modified fermentation medium and taking the hydrochloric acid methanol solution as a precipitating agent, the yield of the melanin is increased to 3.856g / L from 1.471g / L, the fermentation period is shortened to 8 days from 12 days, and the purity of the crude melanin extract is high, thereby being conducive to the purification and reducing the damage to the structure thereof in the purification process.

Description

technical field [0001] The invention belongs to the technical field of preparing melanin by liquid state fermentation of microorganism Lachnum, and in particular relates to extracting melanin from Lachnum fermentation liquid by using methanolic hydrochloric acid solution as a precipitating agent and adopting an improved fermentation medium to improve Methods of melanin production. Background technique [0002] At present, melanin can be chemically synthesized by oxidation of tyrosine or its derivatives, extracted from animal and plant materials, or synthesized by microorganisms. For example, Chinese Patent Application Nos. 92112247.0 and 91104469.8 respectively disclose a method for preparing melanin by using mammalian animal hair as raw material and black sesame as raw material, leaching with sodium hydroxide solution and using hydrochloric acid as a precipitating agent to precipitate melanin . However, with people's understanding of the safety of melanin synthesized from...

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Problems solved by technology

British "Fungus Research" (Mycological Research, 2004, 108 (8): 974-978) once reported that melanin was obtained by culturing in PDB medium for 10 days, and directly participated in the biosynthesis of melanin with L-tyrosine, which was processed by tyrosinase The catalysis of (TYR) makes L-tyrosine hydroxylated to form L-dopa, and oxidized to L-dopaquinone, and L-dopaquinone finally forms melanin through a series of reactions; Cu 2+ is the active center of TYR, Cu 2+ The introduction of TYR can enhance the activity of TYR and ultimately determine the speed and yield of melanin production; however, the current method of using the above-mentioned medium to synthesize melanin has a low yield, and the previous research results are usually only 1.2-1.4g / L, and the fermentation cycle is generally 12-15 days

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