Method for degrading lignin in sunflowerseed meal by Aspergillus oryzae laccase induced by nitrosoguanidine

Abstract

The invention discloses a method for degrading lignin in sunflowerseed meal by Aspergillus oryzae laccase induced by nitrosoguanidine, which relates to the biodegradation field. The invention comprises the following steps: S01: mutagenizing Aspergillus oryzae laccase with high yield by nitrosoguanidine in a petri dish; S01: mutagenizing Aspergillus oryzae laccase with high yield by nitrosoguanidine; S02: The mutant strain was transferred to PDA plate for culture; S03: 20% by volume of liquid strain 50% of them were inoculate into laccase producing medium; S04: purification of high-yield laccase from Aspergillus oryzae; S05: the sunflower meal is washed and dried, and then crushed into granules; S06: adding sunflower meal particles and culture nutrient solution into the sterile tank, stirring until the solid-liquid mixture is uniform and flat; S07: inoculating Aspergillus oryzae with high-yield laccase in a sterile tank; S08: Lignin degradation complete. Aspergillus oryzae laccase withhigh yield is mutate by nitrosoguanidine, that obtained crude laccase is purify, lignin is rapidly degraded by fermentation of laccase and sunflower meal in a sterile tank, the degradation conversionefficiency of lignin is improved, and the degradation effect is stable.

Description

technical field [0001] The invention belongs to the field of biodegradation, in particular to a method for degrading lignin in sunflower meal by mutagenizing aspergillus oryzae laccase with nitrosoguanidine. Background technique [0002] Nitrosoguanidine (NTG), used for mutation breeding, is a recognized chemical supermutagen with remarkable effect; Nitrosoguanidine belongs to alkylating agent, and alkylating agent is a kind of quite effective chemical inducer in mutation Mutagen, this type of mutagen has one or more active alkyl groups, which can easily replace the active hydrogen atoms in the DNA molecule, so that the bases and phosphates on the DNA molecule are alkylated, resulting in base pairing during DNA replication mutation due to errors. [0003] The high-yield laccase from Aspergillus oryzae mainly degrades the phenolic structure in lignin, and the high-yield laccase from Aspergillus oryzae can also degrade non-phenolic structures in the presence of mediators. Th...

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Problems solved by technology

[0004] The object of the present invention is to provide a method for degrading lignin in sunflower meal by mutagenizing Aspergillus oryzae laccase with nitrosoguanidine, through mutagenizing high-yield laccase of Aspergillus oryzae with nitrosoguanidine, purifying the obtained crude laccase, and using it in The fermentation of laccase and sunflower meal in aseptic tanks quickly degrades lignin, which solves the problem that the existing high-yield laccase components of Aspergillus oryzae cannot be kept consistent and the conversion efficiency is low

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