Spo0A links de novo fatty acid synthesis to sporulation and biofilm development in Bacillus subtilis.TAPA DE REVISTA

PEDRIDO M.E.; DE OÑA P.; GOÑI, A.; RAMIREZ WALTER; LEÑINI C.; GRAU R.

MOLECULAR MICROBIOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2013 vol. 87 p. 348 - 367

0950-382X

During early development in Bacillus subtilis, the sporulation-committed cell undergoes substantial membrane rearrangements to generate two cells of different sizes and fates: the mother cell and the forespore. Here, we demonstrate that the master regulator Spo0A reactivates lipid synthesis during development. Maximal Spo0A-dependent lipid synthesis occurs during the stages of asymmetric division and forespore engulfment. Spo0A reactivates the accDA operon that encodes the carboxylase component of the acetyl-CoA carboxylase enzyme, which catalyses the first and rate-limiting step in de novo lipid biosynthesis, malonyl-CoA formation. The disruption of the Spo0A-binding box in the promoter region of accDA impairs its transcriptional reactivation and blocks lipid synthesis. The Spo0A-insensitive accDA0A cells were proficient in planktonic growth but defective in sporulation (σE activation) and biofilm development (cell cluster formation and water repellency). Exogenous fatty acid supplementation to accDA0A cells rescues their inability to synthesise lipids during development and restores sporulation and biofilm proficiencies. The transient exclusion of the lipid synthesis regulon from the forespore and the known compartmentalisation of Spo0A and ACP in the mother cell suggest that de novo lipid synthesis is asymmetrically excluded from the forespore. The significance of the Spo0A-controlled de novo lipid synthesis during B. subtilis development is discussed.