TABLE 1.

Growth of strain CYKS1 on various organic sulfur compounds^a

Organic sulfur compound	Growthb
Methyl sulfide	++
Benzyl sulfide	++
Benzyl sulfone	++
4,4′-Thiophenol	−
Phenyl sulfide	+
Phenyl sulfone	−
Thiophene	++
2-Methyl thiophene	++
3-Methyl thiophene	+
Thianaphthene	+
DBT	++
DBT-O2	++
Methyl disulfide	−
Benzyl disulfide	++
p-Tolyl disulfide	−
Thiazole	++
4,5-Dimethylthiazole	++
2-Methyl-β-naphthiothiazole	−
Thianthrene	−
Trithiane	++

^aStrain CYKS1 was grown aerobically in 50-ml test tubes containing 5 ml of MSM with various organic sulfur compounds (0.3 mM) as the sole sulfur source. Butyl rubber stoppers were used. Cell growth was determined by measuring optical density of culture broth samples at 600 nm. Sulfur-free MSM was used as a negative control. 

^b++, good growth (more than 2 U of A₆₀₀) within approximately 3 days or less; +, growth time longer than 3 days; −, no growth.