Aerobic Bacterial Catabolism of Dimethylsulfoniopropionate

Abstract

Dimethylsulfoniopropionate (DMSP) is an organosulfur zwitterion produced by various marine algae and Bacteria as an osmolyte, cryoprotectant, defense molecule, and antioxidant. In the marine environment in particular, it can be degraded by the Bacteria in various ways. In this chapter we cover the biochemistry and physiology of the various pathways of DMSP catabolism, including the three core enzymes DMSP dethiomethylase (EC 4.4.1.3, the so-called DMSP lyase), DMSP demethylase (EC 2.1.1.269), and DMSP CoA transferase/lyase (EC 2.3.1.x). Six isoenzyme classes of DMSP dethiomethylase have been purified and confirmed in marine Bacteria thus far, with a further isoenzyme found in algae that may also occur in Bacteriathese are all discussed in detail. Methodologies for enzyme assays and the synthesis of DMSP hydrochloride are given, including those for radio-and stable-isotope labelling.

Distribution and physical–biological controls of dimethylsulfide in the western tropical Indian Ocean during winter monsoon

“…might be the dominant DMSP-producer in the WTIO (Keller et al, 1989;Herr et al, 2019;Tripathy et al, 2020). Phytoplankton release of intracellular DMSP into seawater through excretion, senescence, zooplankton grazing, and viral attack, formed the DMSPdmaximum bands at the SCM depth Boden and Hutt, 2019).…”

“…Dimethylsulfoniopropionate (DMSP), as a DMS precursor, is primarily produced by a variety of phytoplankton in the euphotic layer (Simóet al, 1998;Bullock et al, 2017). Most DMSP released into seawater is utilized by bacteria through demethylation or demethiolation pathways leading to production of methanethiol, which represents a source of energy, carbon, and reduced sulfur, while the proportion utilized by the bacterial lyase pathway to produce DMS is minor, i.e.,<20% (Kiene et al, 1999;Boden and Hutt, 2019). In addition to microbial metabolism, certain algae such as Phaeocystis that have highly active DMSP lyases, can degrade DMSP to DMS, which is released into seawater (Keller et al, 1989;Steinke et al, 2007).…”