Significance of Bacterial Hydrolases in Particle Degradationand Carbon Flow Pathways in the Ocean's Mesopelagic Zone

重要的是要了解在海洋上层形成的颗粒是如何从上层沉入底栖动物的。细菌在颗粒沉入海底的过程中起着重要作用。与这些颗粒有关的大部分有机物被转化为溶解态，这种形式可以被浮游植物和其他细菌利用来生长。阿扎姆博士之前的研究结果提出了一种假设，即附着的细菌通过向颗粒中分泌某些酶（水解酶），导致颗粒的大规模溶解和破碎。结果是，大部分溶解的有机物质从颗粒中扩散出来，被自由生活的细菌利用。在本研究中，这一途径的大小和机制进行了探讨。这项研究的重点是几种酶的调控，这些酶控制着从颗粒到溶解状态的转化。该研究有助于理解细菌在有机物生物地球化学循环途径中的作用。

It is important to understand how particles which are formed in the upper layers of the ocean are transformed as they sink out of those upper layers into the benthos. Bacteria play a major role in the transformation of the particles on their way to the bottom. Much of the organic matter associated with these particles is converted to the dissolved state, a form in which it can be utilized by phytoplankton and other bacteria for growth. Dr. Azam's previous results have led to the hypothesis that the attached bacteria, via secretion of certain enzymes (hydrolases) into the particle, are responsible for large scale solubilization and fragmentation of the particles. The result is that most of the dissolved organic material diffuses out of the particle and is utilized by free-living bacteria. In the present study, the magnitude and mechanisms of this pathway are explored. The research focuses on the regulation of several enzymes that control the transformation from the particulate to the dissolved state. The study contributes toward the understanding of the role of bacteria in biogeochemical cycling pathways of organic matter.