Fig. 4. DMS concentration, DMSP consumption, and growth condition of bacterial cultures in minimal medium.

(A) Time courses for production of DMS (nmol/ml) and DMSP utility (%). DMS in headspace: The DMS concentration in treatment and the values were direct measurements of DMS by GC-MS. DMS in liquid: The DMS concentration in the treatment medium and the values were calculated based on Bunsen solubility coefficient. The line chart shows the percentage of DMSP in treatment medium starting from 0.1 mM DMSP. (B) Bacterial cell number and optical density at 600 nm (OD₆₀₀) value. Bar charts show the cell number measured by flow cytometry. Line charts show the value of OD₆₀₀ which started from 10⁸ cell/ml. BA, before acclimation; mini, control without DMSP; mini + DMSP, treatment with DMSP; mini OD, control OD₆₀₀ value; mini + DMSP OD, treatment OD₆₀₀ value. (C) The DMSP metabolism of 8E were determined using ³⁴S and ¹³C label stable isotope at the single-cell level. Example parallel images of ¹²C¹⁴N counts, sulfur isotope ratio (³⁴S/³²S), and carbon isotope ratio (¹²C¹³C/¹²C). (D) ³⁴S atomic % and ¹³C atomic % isotopic composition of ROIs in the scatterplot. The nature ³⁴S atomic % is 4.25 and ¹³C is 1.07; ROIs higher than the value were marked as enriched. ND, not determined.