Accepted Article This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as doi: 10.1111/jam.13760 This article is protected by copyright. All rights reserved. DR. CARLOS F. PEÑA (Orcid ID : 0000-0002-0381-6529) Article type : Original Article Oxygen uptake rate in alginate producer (algU+) and non-producer (algU-) strains of Azotobacter vinelandii under nitrogen-fixation conditions T. Castillo 1 , I. López 1 , C. Flores 1 , D. Segura 2 , A. García 1 , E. Galindo 1 and C. Peña 1* 1 Departamento de Ingeniería Celular y Biocatálisis, 2 Departamento de Microbiología Molecular Instituto de Biotecnología, Universidad Nacional Autónoma de México, Apdo. Post. 510-3 Cuernavaca, 62250, Morelos, México. * Corresponding author: carlosf@ibt.unam.mx; Phone: +52(777)3291617 Abbreviated running headline: Oxygen uptake rate in A. vinelandii Abstract Aims The sigma E (AlgU) in Azotobacter vinelandii has been shown to control the expression of cydR gene, a repressor of genes of the alternative respiratory chain, and alginate has been