Screening and Isolation of Highly Efficient Cellulose-degrading Microorganisms and Construction of Complex Microbial System

This study almed to screen a highIy efficient ceI uIose-degrading compIex microbial system from soiI and rotten straw and then study its appIication to natural ceI uIose. The isoIated stralns were preIiminariIy screened with Congo red stalning and the ceI uIases activities were determined with DNS method. The non-antagonis-tic highIy efficient ceI uIos-degrading stralns were seIected and cuItured combinedIy for deveIoping a ceI uIose-degrading compIex microbial system. The resuIts showed that the CMC enzyme activity of the mixed cuIture of the three fungi stralns was higher than those of the cuItures of the three singIe stralns. The morphoIogical and moIecuIar bioIogical identification indicated that F1 was Botryosphaeria, F2 was Rhi-zopus oryzae, and F5 was Fusarium oxysporum. When straw was used as carbon source, the CMC enzyme activities of F1, F2 and F5 were 39.2, 31.4 and 40.6 IU/mI, respectiveIy; whiIe the CMC enzyme activity of the mixed cuIture of F1＋F2＋F5 was 50.12 IU/mI, which was increased by 23% compared to that of the singIe straln of F5. The experimental resuIts indicated that the ceI uIose-degrading effect of the compIex microbial system was better than those of the singIe fungi stralns, and the singIe stralns of F1, F2 and F5 had certaln deveIopment potentials.

论郭璞身份认同的错位——兼论汉末魏晋时期思想与学术的历史流变

作为东晋著名的学者与文学家,郭璞对政治活动的参与是以占筮的方式来进行的,因而在同时代的士人眼中,他的身份是“占卜家”;但就其政治思想而言,郭璞仍坚持汉儒之学,认为只有士人身份方是参与政治活动的正途,因而其自我定位仍为士人。在这种情况下,形成了郭璞与其他士人对其身份认同的不一致性,而这种“士人”与“占卜家”身份认同的矛盾正是导致其悲剧的一生的根本原因。就时代与学术背景而言,郭璞身份认同的借位,也是汉末魏晋时期社会动荡不安,学术思想波动变化所致。