Breeding Of The Strain Of Lignocellulose Degradation In Bamboo

Bamboo fiber is a kind of new environmental friendly and cool-type fiber with capacious foreground. It has many values, such as, antibacterial, resistance to wear, water absorbability, permeability.The resource of bamboo is abundant in China. If the bamboo fibril is exploitated, it will have an important effect on textile domain. Biological degumming is a new developing way, it is very important to entironment protection to decompose natural fibre. So biological is an advanced and green degummed method.This paper focused on the selection and identify of the Lignin degradation fungus,breeding the strain and studying the cultivation condition of the mutant strain. The detailed contents were as followed:According to a analytical method established in our laboratories taking Azure-B as substrates to be decolor by Mnp and Lip and showing color change, soil and humus samples were used for the screening of lignolytic enzyme producing strains. Three high effective strains were isolated out, and the strain 1023 was shown to be a excellent lignolytic enzyme producer with a high activity reaching maximum values. We measured the growth curve of 1023 by means of weighing the dry hypha. The results showed that the logarithmic metaphase of growth of the 1023 were 70 hours.The results indicate that with Kirk medium,30℃and 140rpm shaking incubation the LIP achieved the maximum activity of about 221 U/L on day 8 and MnP reached the maximum activity of about 403 U/L on day 8.A high twin enzyme producing strain N1023j with genetic stability was obtained from 1023 by mutagenesis with N+ ion implantation (30KeV, 100×1014ions/cm2,10-3Pa,10mA,10s). After the screening of fermentation using a shake flask, its activity of Mnp and Lip reached 513U/L and 270.9U/L, respectively.Compared with 1023, the enzyme activity enhanced 27.29% and 22.58%, respectively.The fermentation conditions were optimized based on the former culture medium and formal fermetation conditions. The results of the experiments showed the best fermentation conditions were as following: loading amount 100mL,culture temperature 35℃, initial pH5.5,rotational speed of 160rpm. The N1023j grew well on the optimized fermentation condition.Its activity of Mnp and Lip reached 631U/L and 340 U/L, respectively. Compared with the formal fermentation condition, the enzyme activity enhanced 22.76% and 23.63%, respectively.The laboratory experiment of degumming of bamboo fibers with the strain 1023 and N1023j.In 30 days, lignin is degradated 33.19%and 43.96% respectively, and selectivity coefficient is 1.76and1.97; and hemicellulose is degradated 18.81% and 22.28% respectively. It was found after 30days treatment that the content of the pectin, wax and lignose of bamboo fibers had a significant reduction except the lignose for which continuous treatment was needed.