Bruton, J. A. University of South Alabama, jodybruton@juno.com
Kiene, R. A. University of South Alabama, rkiene@jaguar1.usouthal.edu
Linn, L. University of South Alabama, llinn@mobile.gulf.net

 
THE FATE OF METHANETHIOL IN SEAWATER: UPTAKE BY BACTERIOPLANKTON AND REACTION WITH DISSOLVED ORGANIC MATTER.
 
Methanethiol (CH3SH) is a major degradation product of both DMSP and methionine. CH3SH is highly reactive and turns over very rapidly in surface seawater, but its fate is poorly understood. We investigated factors which might control the loss of CH3SH and ultimately the fate of its sulfur. Size fractionation experiments showed that the majority of CH3SH loss was associated with the bacterial size fraction in seawater (0.2-0.6 um). Support for an active role of bacteria in consuming CH3SH came from experiments in which heat treatment decreased losses, while addition of live bacteria to 0.2 Ám-filtered seawater increased loss rates. Further experiments with 35S-CH3SH showed that the sulfur was rapidly incorporated into particulates, presumably bacterial cells. Loss of CH3SH in the absence of live bacteria was slower but still occurred. Additions of 35S-CH3SH to 0.2 Ám filtered seawater showed that the label quickly became associated with a dissolved non-volatile pool. The addition of Suwannee River humic or fulvic acids accelerated the incorporation of 35S-CH3SH into the dissolved non-volatile pool indicating that reaction with seawater DOM might be involved in CH3SH loss. The results suggest that CH3SH is utilized by bacteria and may also be incorporated into DOM.
 
Day: Thursday, Feb. 4
Time: Poster
Location: Sweeney Center
 
Code: SS37TH0313S