Table 3.

Sterol derivatives recovered from cultures of the T. thermophila WT and KO607 mutant^a

Compound(s) measured	Amt of sterol (μg/ml) in indicated culture with:
	Stigmasterol		β-Sitosterol		Sitostanol
	WT	KO607	WT	KO607	WT	KO607
Cholesta-5,7,22-trien-3β-ol	3.62 ± 0.07	−	1.93 ± 0.31	−	2.22 ± 0.37	−
Stigmasta-5,7,22-trien-3β-ol	2.23 ± 0.22	2.01 ± 0.46	0.61 ± 0.09	0.88 ± 0.12	2.20 ± 0.35	2.35 ± 0.25
Cholest derivativesb	4.42 ± 0.15	−	2.22 ± 0.38	−	2.22 ± 0.37	−
Stigmast derivativesc	2.23 ± 0.22	2.01 ± 0.46	1.52 ± 0.22	2.78 ± 0.36	8.56 ± 1.20	7.02 ± 1.12

Strains were grown in SPP medium with 20 μg/ml of the indicated sterol. At 48 h of incubation, sterols were extracted and quantified by GC-MS, as described in Materials and Methods. The results are the mean values of two determinations ± standard deviations (combined from three independent experiments). −, not detected.

^bCholest derivatives are all bioconversion products without a C₂₄ ethyl group formed in cultures.

^c“Stigmast derivatives” refers to all the bioconversion products formed preserving the C₂₄ ethyl group. For details, see Fig. 1.