Study On The Breeding Of Production Stains And Fermentation Of Starch /polyethylene Degradation Actinomycetes Streptomyces Albogriseolus

At present the research of polyethylene degradation bacteria mainly concentrated in bacteria and fungi, actinomycetes as degradation strains are rarely reported. Aactinomycetes was gained from soil and identified as the starting stain. With Streptomyces albogriseolus as the starting stain, using six kinds of methods for mutagenesis, as following: ultraviolet radiation 、 microwave 、 acridine orange 、hydroxylamine hydrochloride 、 Li Cl and complex mutation with acridine orange and ultraviolet radiation, in order to observe the effect of the mutation. As the result, when the wavelength of ultraviolet radiation is 254 nm, the irradiation distance is 20 cm for 50 s, we can get the highest positive mutation rate 16.43%,the enzyme activity was increased by 3.21 times as the original strain, the degradation of polyethylene was increased by 1.3 times as the original strain; When microwave power is 700 w, and the mutagenesis is180 s, we can get the highest positive mutation rate 16.05%,the enzyme activity was increased by 2.89 times as the original strain, the degradation of polyethylene was increased by 1.26 times as the original strain; When the concentration of acridine orange is 1×10-3g/m L,, we can get the highest positive mutation rate 21.30%,the enzyme activity was increased by 3.12 times as the original strain, the degradation of polyethylene was increased by 1.3 times as the original strain; When the concentration of ydroxylamine hydrochloride is 0.3 g/L, the enzyme activity was increased by 2.48 times as the original strain, the degradation of polyethylene was increased by 1.21 times as the original strain; When the concentration of Li Cl is 1.6%, the enzyme activity is 9.90U/m L, the enzyme activity was increased by 1.04 times as the original strain; after complex mutation with acridine orange and ultraviolet radiation, thedegradation capacity is improved, 41.80% higher than the original strain, it was avaluable and potential strain in the research of degradation of Starch/polyethylene powder.After being cultured for several days, amylase in fermentationwas purified by the method of(NH4)2SO4fractional precipitation, the experimental results show that the best concentration of(NH4)2SO4 separation is 60%- 80%, the optimun reaction for amylase produced by Streptomyces albogriseolus temperature was determined to be 40℃, and there still was the excellent enzyme activity after being incubated within 30 ℃-50 ℃; The best p H was 7.5; Theenzyme activity was promoted by mental ions Ca2+and K+, and inhibited by Cu2+and Fe3+.With amylase as the research object, which can degradation of starch /polyethylene, experiment determining the sample contents, the culture medium composition such as carbon sources, nitrogen sources, the optimum liquid culture volume, the optimum rotation speed, fermentation conditions and optimum medium was optimized, on the basis of single factor experiment, we do the orthogonal experiment, the result of experiment showed that, the optimum liquid culture volume was 500 m L in 150 m L, the best carbonsources was lactose, and it optimum initial concentrations is 1%, the best nitrogensources was beef paste, and it optimum initial concentrations is 1%, the best rotation speed is 200 r/min, on this condition, we get, the best initial p H is 7.5, low alkaline, the best temperature is 37℃. Under the condition of the fermentation, we can get the highest enzyme activity35.7U/m, increased by1.16 times as the original strain. Which will proved technical support for industrial production.The purpose of this paper is to study a actinomycetes strain, which can degradation of starch /polyethylene, it can enrich polyethylene degradation strains resources, and it is meaningful to study the material and energy cycle of soil micro ecosystem, a strain, which could degradation of starch /polyethylene, was obtained by an induced mutation technology of complex mutation with acridine orange and ultraviolet radiation, according to the research, we can know the fermentation condition and the best conditions for the enzyme produce, it has a great significance to industrial production.