Sigma (σ) factors are key regulatory proteins that control the transcription initiation in prokaryotes. In response to environmental or developmental cues, σ factors initiate the transcription of necessary genes responsible for maintaining a life-sustaining metabolic balance. Due to the significant role of σ factors in bacterial metabolism, their rational engineering for commercial metabolite production in photoautotrophic, cyanobacterial cells is a desirable venture. As cyanobacterial genomes typically encode multiple σ factors, effective execution of metabolic engineering efforts largely relies on uncovering the complicated gene regulatory network and further characterization of the members of σ factor regulatory circuits. This review outlines the prospects of σ factor in metabolic engineering of cyanobacteria, summarizes the challenges in the path towards an efficient strain construction and highlights the genomic context of putative regulators of cyanobacterial σ factors.

Sigma (σ) 因子是控制原核生物转录起始的关键调节蛋白。为响应环境或发育线索，σ 因子启动负责维持维持生命的代谢平衡的必要基因的转录。由于 σ 因子在细菌代谢中的重要作用，它们在光合自养蓝细菌细胞中用于商业代谢物生产的合理工程是一个理想的冒险。由于蓝藻基因组通常编码多个 σ 因子，代谢工程工作的有效执行很大程度上依赖于揭示复杂的基因调控网络和进一步表征 σ 因子调控回路的成员。本综述概述了σ因子在蓝藻代谢工程中的前景，