白腐菌Panus conchatus降解稻草木素机理研究──(一)低分子木素降解产物各组分的分离及特征

Investigations related to biodegradation of lignin in rice straw by Panus conchatus──Ⅰ.Isolation and characterization of low-molecular weight fractions of the lignin degradation products

经白腐菌Panusconchatuss发酵15天的稻草用乙酸乙酯进行抽提可有效分离出生物作用后的低分子量木煮降解产物。利用这些低分子降解产物在酸碱度不同的介质以及不同的有机溶剂中的溶解度不同进一步分离、分级和提纯，获得酚类（LP），芳香酸类（LA1—4）以及中性物质三个组份。我们发现LP与LA是降解产物中的主要组份，它们的得率分别为51．1％和34．4％。如此高的LP得率是白腐菌P．conchatus降解稻草木素的重要特征。本文还利用红外光谱和核磁共振技术对LP和LA中最多的一个组份LA—1的可能化学结构特征进行剖析。

Low-molecular weight lignin degradative product was efficiently isolated byextraction of decayed rice straw with ethyl acetate. The low-molecular weight productsof the lignin degradation were further fractionated into phenolic (LP), aromatic acid(LA) and neutral (NS) fractions by means of so1ubi1ity in different basic solutions andorganic solvents. It was found that LP and LA were main ftactions and the yield of LPand LA was 51. 1% and 34. 4% respectively. High yield of LP was an important featherof lignin biodegradation by P. conchatus. LP and LA ftactions were further characterizedby IR and 1H-NMR spectroscopy.