VARIATION REGULATION AND ACTIVITY OF EXTRACELLULAR LACCASE PRODUCTION OF WHITE ROT FUNGI ON VARIOUS NATURAL LIGNOCELLULOSIC SUBSTRATES

摘要

Variation regulation and activity of extracellular laccase production of white rot fungi in the various lignocellulosic natural substrates medium were studied. Many of Letinula strains can change the color of natural lignocellulosic substrates in solid and liquid medium. But the degree of the substrates color changed by different strains varied obviously. Some of excellent strain such as strains 2,4,6,9 can rapidly change color of natural lignocellulosic substrates from black brown to and light yellow to colorless. The value of laccase activity were produced by strains 2,4,6,9 are all the high level at same times. So effect of producing laccase related to color of natural lignocellulosic substrets changing and lignin biodegrading. The time of laccase secreted by strains and the most high peak value of laccase activity reaching varied grandly to different strains fermenting in various natural substances. The activity of laccase secreted by same strain is higher in pulp wastewater medium than in sawdust powder liquid medium so that black and turbid pulp wastewater can turn to colorless and lucid. In general, the laccase activity has increasing at first days and decreasing rapidly at follows days then from increasing to decreasing again in incubation period.