Gene expression in spatiotemporal distribution improves the ability of cells to respond to changing environments. For microbial cell factories in artificial environments, reconstruction of the target compound's biosynthetic pathway in a new spatiotemporal dimension/scale promotes the production of chemicals. Here, a genetic circuit based on the Esa quorum sensing and lac operon was designed to achieve the dynamic temporal gene expression. Meanwhile, the pathway was regulated by an Lcysteine-specific sensor and relocalized to the plasma membrane for further flux enhancement to L-cysteine and toxicity reduction on a spatial scale. Finally, the integrated spatiotemporal regulation circuit for L-cysteine biosynthesis enabled a 14.16 g/L L-cysteine yield in Escherichia coli. Furthermore, this spatiotemporal regulation circuit was also applied in our previously constructed engineered strain for pantothenic acid, methionine, homoserine, and 2-aminobutyric acid production, and the titer increased by 29, 33, 28, and 41%, respectively. These results highlighted the applicability of our spatiotemporal regulation circuit to enhance the performance of microbial cell factories.

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A Gram-stain-positive, anaerobic, spore-forming, rod-shaped (0.4–0.6 µm×2.5–3.2 µm), flagellated bacterium, designated strain YB-6T, was isolated from activated sludge of an anaerobic tank at Weizhou marine oil mining wastewater treatment plant in Beihai, Guangxi, PR China. The culture conditions were 25–45 °C (optimum, 37 °C), pH 4–12 (pH 7.0) and NaCl concentration of 0–7 % w/v (0%). Strain YB-6T grew slowly in petroleum wastewater and removed 68.2 % of the total organic carbon in petroleum wastewater within 10 days. Concentrations of naphthalene, anthracene and phenanthrene at an initial concentration of 50 mg l−1 were reduced by 32.8, 40.4 and 14.6 %, respectively, after 7 days. Phylogenetic analysis of the 16S rRNA gene sequence indicated that strain YB-6T belongs to Clostridium cluster I and is most closely related to Clostridium uliginosum CK55T (98.5 % similarity). The genome size of strain YB-6T was 3.96 Mb, and the G+C content was 26.5 mol%. The average nucleotide identity value between strain YB-6T and C. uliginosum CK55T was 81.9 %. The major fatty acids in strain YB-6T were C14 : 0 FAME, C16 : 0 FAME and summed feature 4 (unknown 14.762 and/or C15 : 2 FAME). The main polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, five unidentified aminophospholipids, one unidentified glycolipid and one unidentified aminolipid. Diaminopimelic acid was not detected in the strain YB-6T cell walls. Whole-cell sugars mainly consisted of ribose and galactose. Based on the results of phenotypic and genotypic analyses, strain YB-6T represents a novel species of the genus Clostridium , for which the name Clostridium weizhouense sp. nov. is proposed. The type strain is YB-6T (=GDMCC 1.2529T=JCM 34754T).