Enzymology of aromatic degradation by pseudomonas cf600 and selected fungi

分解生物圈中的有机物是地球上所有生物的任务，但最终降解最肮脏和最复杂的分子福尔斯落在细菌和真菌身上。虽然这些生物已经进化到可以处理各种各样的天然基质，但它们越来越多地受到人造化合物的挑战，这些化合物可能会或可能不会降解。 因此，这些降解活动是有趣的：了解自然界在其令人难以置信的多样性中已经能够做到的事情;微生物如何以及为什么与人造化合物一起失败;以及如何适应或修改这些活动以降解化学废物，清理污染物或转化天然材料。 我们感兴趣的是生物降解反应，由单一种类的细菌和真菌进行，通常是为了获得能量和支持生长。 重点是有限数量的简单芳香族化合物-苯酚和羟基苯甲酸酯的好氧降解。 这些化合物形成了多种有毒化学物质的核心，这些化学物质不能被人类和其他高等动物降解。 细菌和真菌降解它们的能力取决于酶的作用，酶是特异性和有效地指导分解序列的细胞内催化剂。 我们正在继续我们的研究选择酶参与降解酚类的土壤细菌，假单胞菌属菌株CF 600，这是最初从活性污泥分离。 该途径的第一个和最后一个酶特别有趣，因为它们需要几种蛋白质以目前尚不清楚的方式一起工作。我们还在研究一系列来自不同真菌的细胞内酶，这些酶降解类似类型的化合物。 我们在这部分项目中的目标是更多地了解真菌中的这种降解酶，它们比细菌的降解酶了解得少，但在自然环境和实验室研究中可能很重要。

Decomposition of organic matter in the biosphere is the task of all organisms on the Earth, but ultimately degradation of the nastiest and most complex molecules falls to bacteria and fungi. While these organisms have evolved to deal with a wide variety of natural substrates, they are increasingly challenged by man-made compounds which they may or may not degrade.  These degradative activities are thus of interest: to know what Nature in its incredible variety is already capable of; how and why microbes fail with man-made compounds; and how these activities might be adapted or modified to degrade chemical wastes, clean up pollutants, or transform natural materials.  We are interested here in biodegradative reactions, carried out by single species of bacteria and fungi, generally to derive energy and support growth.   The focus is on aerobic degradation of a limited number of simple aromatic compounds-phenols and hydroxybenzoates.  These compounds form the nucleus for a wide variety of chemicals that are toxic and which cannot be degraded by humans and other higher animals.  The ability of bacteria and fungi to degrade them is dependent on the action of enzymes, intracellular catalysts that specifically and efficiently direct the breakdown sequence.  We are continuing our studies of selected enzymes involved in the degradation of phenols by a soil bacterium, Pseudomonas sp. strain CF600, which was originally isolated from activated sewage sludge.  The first and last enzymes of the pathway are particularly interesting as they require several proteins to work together in ways that are currently not well understood. We are also looking at a range of intracellular enzymes from a diverse group of fungi that degrade similar types of compounds.  Our goal in this part of the project is to learn more about such degradative enzymes in fungi, which are less well understood than those of bacteria, but which are likely to be important in the natural environment as well as in laboratory studies.