## 4 Conclusions  
In this paper, the production of SCPs by efficient continuous gas fermentation under autotrophic conditions was studied for the first time. Studies have shown that under the condition of a high inoculation rate, the growth of these cells is improved, the lag period is shortened, and the maximum CDW is also improved. The use of stainless steel fillers can increase the mass transfer coefficient (K\({}_{\text{L}}\),\(\alpha\)) of oxygen to a certain extent, while at the same time improving the mass transfer efficiency of the gas mixture. By adding 1000 cm\({}^{3}\) stainless steel packing material to the in-house bioreactor, the mass transfer coefficient of oxygen was effectively increased, which in turn facilitated the fermentation process. The flow acceleration used in this study was 0.7675 mL/min, and the fermentation cycle was set at 14 days. During the 14-day fermentation cycle, the average yield of continuous fermentation reached 25.17 g/L, which was 62.61% higher than that of batch fermentation. The method is shown to be highly efficient in the production of single-cell proteins. By optimizing the inoculum amount and using stainless steel packing materials, the efficiency of gas fermentation under autotrophic conditions can be significantly improved, and the production of single-cell proteins can be promoted. This study provides a necessary theoretical basis and practical reference for the future application of gas fermentation technology on an industrial scale. Further research can focus on optimizing reactor designs and fermentation conditions to achieve higher yields and economic benefits. Conceptualization, S.F. and Y.L. ; methodology, S.F. and Y.L. ; software, Y.L. ; validation, S.F., L.G. and K.L. ; formal analysis, S.F. and L.C. ; investigation, D.C.; resources, L.G; data curation, S.F. ; writing--original draft preparation, S.F. and L.C. ; writing--review and editing, L.G. ; visualization, L.C. ; supervision, D.C.; project administration, L.C. ; funding acquisition, Y.L. All authors have read and agreed to the published version of the manuscript. This research was supported by the National Nature Science Foundation of China for Young Scholars [grant number 42007304] and National Key Research and Development Program of China [grant number 2022 YFC2106002], and primarily supported by Chengdu Heqi Biotechnology Co., Ltd.  
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