Influence of reduced sulfur on carbon fixation efficiency of Halothiobacillus neapolitanus and its mechanism

Main components of free organic carbon generated by obligate chemoautotrophic bacteria that inhibit their CO2 fixation

“…Importantly, the self-generated extracellular free organic carbon (EFOC) generated by chemoautotrophic bacteria has an inhibitory feedback effect on bacterial growth and CO 2 fixation. 19 , 26 According to several reports, membrane reactors promote bacterial growth and CO 2 fixation by separating EFOC from the culture environment, 26 , 27 confirming that EFOC has an inhibitory effect on the growth and CO 2 fixation of autotrophic bacteria. Consequently, the inhibition exerted by self-generated EFOC contributes to the relatively low growth rate and low CO 2 fixing efficiency of chemoautotrophic bacteria and may be the most important reason for their inability to sustain efficient autotrophic growth and CO 2 fixation.…”

“…In addition to these internal factors, the growth rate of chemoautotrophic bacteria is also affected by environmental factors, such as temperature, the carbon source, pH, O 2 , and the energy source, which play important roles in the bacterial growth and the CO 2 fixation of autotrophic microorganisms. 19 , 20 It has also been demonstrated that external organic compounds generally have a negative impact on the CO 2 assimilation and cell growth of chemoautotrophic bacteria. 21 , 22 , 23 , 24 , 25 …”

“…In contrast to previous research, which mainly focused on the external factors that inhibit bacterial CO 2 fixation, 11 , 19 , 20 in this study, we investigated the components of self-generated EFOC that inhibit CO 2 fixation by chemoautotrophic bacteria and their mechanisms. Our results provide a theoretical basis for developing targeted measures to remove the main inhibitory components from cultures of chemoautotrophic bacteria to improve their CO 2 fixation, such as the affinity adsorption of small-molecule EFOC, and circulating flow technology with microfiltration membranes for large-molecule EFOC.…”

Effect of electron donors on CO2 fixation from a model cement industry flue gas by non‐photosynthetic microbial communities in batch and continuous reactors

“…For instance, Hu et al (2010a) and Hu, Wang, Zhang, Le, and Fu (2014) evaluated the effect of Na 2 S, Na 2 S 2 O 3 and NaNO 2 on the CO 2 fixation under aerobic conditions (air/CO 2 , 80:20% v/v; H 2 /O 2 / CO 2 , 80:10:10% v/v) using marine non-photosynthetic microbial communities. Similarly, Wang et al (2017) assessed the influence of Na 2 S 2 O 3 on carbon fixation by Halothiobacillus neapolitanus from a gas containing CO 2 /O 2 (10:21%). Other studies have reported anaerobic conditions; for example, Ye et al (2020) evaluated the performance of CO 2 fixation by Paracoccus denitrificans PJ-1 using different Na 2 S 2 O 3 concentrations applying a mixture of CO 2 /N 2 (20:80% v/v), whereas Hu et al (2010b) and Hu et al (2011) reported the carbon fixation from CO 2 /N 2 (20:80% v/v) using a non-photosynthetic microbial community and Na 2 S, Na 2 S 2 O 3 and NaNO 2 .…”

“…Similarly, Wang et al. ( 2017 ) assessed the influence of Na 2 S 2 O 3 on carbon fixation by Halothiobacillus neapolitanus from a gas containing CO 2 /O 2 (10:21%). Other studies have reported anaerobic conditions; for example, Ye et al.…”