Variability in the apparent CO₂ fixation yield of four aerobic sulfur-oxidizing bacteria (Halothiobacillus neapolitanus DSM 15147, Thiobacillus thioparus DSM 505, Thiomonas intermedia DSM 18155, and Starkeya novella DSM 506) in autotrophic culturing was studied, and mutual effects of key intrinsic factors on CO₂ fixation were explored. DSM 15147 and DSM 505 exhibited much higher CO₂ fixation yields than DSM 18155 and DSM 506. The differences in CO₂ fixation yield were determined not only by cbb gene transcription, but also by cell synthesis rate, which was determined by rRNA gene copy number; the rRNA gene copy number had a more significant effect than cbb gene transcription on the apparent CO₂ fixation yield. Moreover, accumulation of EDOC was observed in all four strains during chemoautotrophic cultivation, and the proportion of EDOC accounting for total fixed organic carbon (TOC; EDOC/TOC ratio) was much higher in DSM 18155 and DSM 506 than in DSM 15147 and DSM 505. The accumulation of EDOC led to a significant decrease in the cbb gene transcription efficiency during cultivation, and a further feedback inhibitory effect on CO₂ fixation.

在自养培养中研究了四种需氧硫氧化细菌（那不勒斯硫代嗜热芽孢杆菌DSM 15147，硫代硫代硫杆菌Thosbacillus thioparus DSM 505，中间硫代杆菌Thomamonas DSM 18155和新奇球菌DSM 506）的表观CO ₂固定产率的变化，并研究了关键内在因素的相互影响探索了CO ₂固定方法。DSM 15147和DSM 505表现出高得多的CO ₂固定的产率比DSM 18155和DSM 506中的CO的差异₂固定产率不仅由下式确定CBB基因转录，但也取决于细胞合成速率，取决于rRNA基因拷贝数；rRNA基因拷贝数比cbb基因转录对表观CO ₂固定产量的影响更大。此外，在化学自养培养过程中，在所有四个菌株中均观察到EDOC的积累，DSM 18155和DSM 506中占固定有机碳总量的EDOC比例（TOC； EDOC / TOC比）比DSM 15147和DSM 505高得多EDOC的积累导致培养过程中cbb基因转录效率的显着降低，并进一步抑制了CO _2的固定。