Role of Alternative Sigma Factor AlgU in Encystment of Azotobacter Vinelandii

Overview

Journal J Bacteriol

Publisher American Society for Microbiology

Specialty Microbiology

Date 1998 Jun 6

PMID 9573166

Citations 18

Authors

S Moreno

R Najera

J Guzman

G Soberon-Chavez

G Espin

Affiliations

Soon will be listed here.

Abstract

Alginate is essential for encystment in Azotobacter vinelandii. Transcription of the algD gene, which codes for GDP-mannose dehydrogenase, a key enzyme in the alginate biosynthetic pathway, is initiated at two promoters, one of which, p2, has sigmaE consensus sequences. AlgU is the A. vinelandii alternative sigmaE factor. In this study, we constructed an algU mutant (SMU88) which, as expected, is impaired in alginate production, encystment, and transcription of the algD gene from the p2 promoter. Plasmid pJMSAT1, carrying the A. vinelandii algU gene, restored alginate production and encystment to SMU88 and to strain UW136, a naturally occurring algU mutant. Plasmid pSMU865, carrying the A. vinelandii mucABCD genes coding for negative regulators of AlgU activity and previously shown to diminish alginate production in the wild-type strain, ATCC 9046, was shown here to impair encystment and transcription of the algD gene from the p2 algU-dependent promoter. Since nonencysting strain ATCC 9046/pSMU865 produced more alginate than some encysting strains, such as UW136/pJMSAT1, we propose an AlgU role in encystment, independent of the structural role that alginate plays in mature cysts.

Citing Articles

The Azotobacter vinelandii AlgU regulon during vegetative growth and encysting conditions: A proteomic approach.

Chowdhury-Paul S, Martinez-Ortiz I, Pando-Robles V, Moreno S, Espin G, Merino E PLoS One. 2023; 18(11):e0286440.

PMID: 37967103 PMC: 10651043. DOI: 10.1371/journal.pone.0286440.

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

Nunez C, Lopez-Pliego L, Ahumada-Manuel C, Castaneda M Front Microbiol. 2022; 13:845473.

PMID: 35401471 PMC: 8988225. DOI: 10.3389/fmicb.2022.845473.

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

Martinez-Ortiz I, Ahumada-Manuel C, Hsueh B, Guzman J, Moreno S, Cocotl-Yanez M J Bacteriol. 2020; 202(24).

PMID: 32989089 PMC: 7685559. DOI: 10.1128/JB.00135-20.

The Role of the ncRNA RgsA in the Oxidative Stress Response and Biofilm Formation in Azotobacter vinelandii.

Huerta J, Aguilar I, Lopez-Pliego L, Fuentes-Ramirez L, Castaneda M Curr Microbiol. 2016; 72(6):671-9.

PMID: 26858204 DOI: 10.1007/s00284-016-1003-2.

Production of polyhydroxybutyrate and alginate from glycerol by Azotobacter vinelandii under nitrogen-free conditions.

Yoneyama F, Yamamoto M, Hashimoto W, Murata K Bioengineered. 2015; 6(4):209-17.

PMID: 25880041 PMC: 4601296. DOI: 10.1080/21655979.2015.1040209.

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