Department of Bacteriology and Biochemistry, Idaho Agricultural Experiment Station, University of Idaho, Moscow, Idaho 83843.
Appl Environ Microbiol. 1986 Jan;51(1):171-9. doi: 10.1128/aem.51.1.171-179.1986.
Degradation of ground and hot-water-extracted corn stover (Zea mays) lignocellulose by Streptomyces viridosporus T7A generates a water-soluble lignin degradation intermediate termed acid-precipitable polymeric lignin (APPL). The further catabolism of T7A-APPL by S. viridosporus T7A, S. badius 252, and S. setonii 75Vi2 was followed for 3 weeks in aerated shake flask cultures at 37 degrees C in a yeast extract-glucose medium containing 0.05% (wt/vol) T7A-APPL. APPL catabolism by Phanerochaete chrysosporium was followed in stationary cultures in a low-nitrogen medium containing 1% (wt/vol) glucose and 0.05% (wt/vol) T7A-APPL. Metabolism of the APPL was followed by turbidometric assay (600 nm) and by direct measurement of APPL recoverable from the medium. Accumulation and disappearance of soluble low-molecular-weight products of APPL catabolism were followed by gas-liquid chromatography and by high-pressure liquid chromatography, utilizing a diode array detector. Identified and quantified compounds present in culture media included p-coumaric acid, ferulic acid, p-hydroxybenzoic acid, p-hydroxybenzaldehyde, protocatechuic acid, vanillic acid, and vanillin. The further catabolism of these APPL-derived aromatic compounds varied with the culture examined, and only S. setonii and P. chrysosporium completely degraded all of them. Some new intermediates of APPL metabolism also appeared in culture media, but the patterns were culture specific. Additional evidence from high-pressure liquid chromatography analyses indicated that one strain, S. badius, converted a water-soluble fraction evident by high-pressure liquid chromatography (7 to 10 min retention time range) into new products appearing at shorter retention times. Mineralization of a [C-lignin]APPL was also followed. The percent C recovered as CO(2), C-APPL, C-labeled water-soluble products, and cell mass-associated radioactivity, were determined for each microorganism after 1 and 3 weeks of incubation in bubbler tube cultures at 37 degrees C. P. chrysosporium evolved the most CO(2) (10%), and S. viridosporus gave the greatest decrease in recoverable C-APPL (23%). The results show that S. badius was not able to significantly degrade the APPL, while the other microorganisms demonstrated various APPL-degrading abilities. The significance of these findings relative to the fate of APPLs in nature was discussed.
被链霉菌viridosporus T7A 降解的地面和热水提取的玉米秸秆木质纤维素生成一种可溶于水的木质素降解中间产物，称为酸沉淀的聚合木质素（APPL）。在含有 0.05%（wt/vol）T7A-APPL 的酵母提取物-葡萄糖培养基中，37°C 下摇瓶通气培养 3 周，研究了链霉菌viridosporus T7A、S. badius 252 和 S. setonii 75Vi2 对 T7A-APPL 的进一步代谢。在含有 1%（wt/vol）葡萄糖和 0.05%（wt/vol）T7A-APPL 的低氮培养基中，通过静止培养研究了黄孢原毛平革菌对 APPL 的代谢。通过比浊法（600nm）和直接测量从中等回收的 APPL 来监测 APPL 的代谢。通过气相色谱和高压液相色谱（利用二极管阵列检测器），跟踪 APPL 代谢过程中可溶性低分子量产物的积累和消失。在培养基中鉴定和定量的化合物包括对香豆酸、阿魏酸、对羟基苯甲酸、对羟基苯甲醛、原儿茶酸、香草酸和香草醛。这些 APPL 衍生芳香族化合物的进一步代谢因所检查的培养而异，只有 S. setonii 和 P. chrysosporium 完全降解了所有这些化合物。APPL 代谢的一些新中间产物也出现在培养基中，但模式是特定于培养的。高压液相色谱分析的其他证据表明，一种菌株 S. badius 将通过高压液相色谱（保留时间 7-10 分钟范围）检测到的水溶性部分转化为出现在较短保留时间的新产物。还跟踪了 [C-木质素]APPL 的矿化。在 37°C 下通过冒泡管培养孵育 1 周和 3 周后，确定每个微生物的 CO(2)回收率、可回收 C-APPL、C 标记的水溶性产物和细胞质量相关的放射性。黄孢原毛平革菌产生的 CO(2)最多（10%），而链霉菌viridosporus 使可回收 C-APPL 的减少量最大（23%）。结果表明，S. badius 不能显著降解 APPL，而其他微生物则表现出不同的 APPL 降解能力。讨论了这些发现与 APPL 在自然界中命运的关系。
