Corrigendum: Genetic Regulation of Alginate Production in a Bacterium of Biotechnological Interest: A Mini-Review.

[This corrects the article DOI: 10.3389/fmicb.2022.

Genetic Regulation of Alginate Production in a Bacterium of Biotechnological Interest: A Mini-Review.

Alginates are a family of polymers composed of guluronate and mannuronate monomers joined by β (1-4) links. The different types of alginates have variations in their monomer content and molecular weight, which determine the rheological properties and their applications. In industry, alginates are commonly used as additives capable of viscosifying, stabilizing, emulsifying, and gelling aqueous solutions.

Cyclic di-GMP-Mediated Regulation of Extracellular Mannuronan C-5 Epimerases Is Essential for Cyst Formation in Azotobacter vinelandii.

The genus belonging to the family, is characterized by the formation of cysts, which are metabolically dormant cells produced under adverse conditions and able to resist desiccation. Although this developmental process has served as a model for the study of cell differentiation in Gram-negative bacteria, the molecular basis of its regulation is still poorly understood. Here, we report that the ubiquitous second messenger cyclic dimeric GMP (c-di-GMP) is critical for the formation of cysts in Upon encystment induction, the levels of c-di-GMP increased, reaching a peak within the first 6 h.

Increased c-di-GMP Levels Lead to the Production of Alginates of High Molecular Mass in Azotobacter vinelandii.

produces the linear exopolysaccharide alginate, a compound of significant biotechnological importance. The biosynthesis of alginate in and has several similarities but is regulated somewhat differently in the two microbes. Here, we show that the second messenger cyclic dimeric GMP (c-di-GMP) regulates the production and the molecular mass of alginate in The hybrid protein MucG, containing conserved GGDEF and EAL domains and N-terminal HAMP and PAS domains, behaved as a c-di-GMP phosphodiesterase (PDE).

Molecular weight and viscosifying power of alginates produced by mutant strains of under microaerophilic conditions.

Alginates are polysaccharides that are of interest in various industrial applications. This is due to the viscosifying properties of alginates, which depends on the weight-average molecular weight. The aim of the present study was to evaluate the changes in alginate quality, in terms of the viscosifying power and weight-average molecular weight of the polymer produced by mutant strains in shake flasks under microaerophilic conditions.

Expression of the sRNAs CrcZ and CrcY modulate the strength of carbon catabolite repression under diazotrophic or non-diazotrophic growing conditions in Azotobacter vinelandii.

Azotobacter vinelandii is a nitrogen-fixing bacterium of the Pseudomonadaceae family that prefers the use of organic acids rather than carbohydrates. Thus, in a mixture of acetate-glucose, glucose is consumed only after acetate is exhausted. In a previous work, we investigated the molecular basis of this carbon catabolite repression (CCR) process under diazotrophic conditions.

Two-component system CbrA/CbrB controls alginate production in Azotobacter vinelandii.

Azotobacter vinelandii, belonging to the Pseudomonadaceae family, is a free-living bacterium that has been considered to be a good source for the production of bacterial polymers such as alginate. In A. vinelandii the synthesis of this polymer is regulated by the Gac/Rsm post-transcriptional regulatory system, in which the RsmA protein binds to the mRNA of the biosynthetic algD gene, inhibiting translation.

The signaling protein MucG negatively affects the production and the molecular mass of alginate in Azotobacter vinelandii.

Azotobacter vinelandii is a soil bacterium that produces the polysaccharide alginate. In this work, we identified a miniTn5 mutant, named GG9, which showed increased alginate production of higher molecular mass, and increased expression of the alginate biosynthetic genes algD and alg8 when compared to its parental strain. The miniTn5 was inserted within ORF Avin07920 encoding a hypothetical protein.