Regulation of the Ald gene encoding alanine dehydrogenase and its induction of ammonium-tolerant nitrogen fixation in Paenibacillus polymyxa WLY78.

ABSTRACT: Paenibacillus polymyxa WLY78, a Gram-positive diazotroph with plant growth promotion and phytopathogen suppression, represents a promising candidate for agricultural biofertilizers. However, its nitrogen fixation capacity is inherently limited by ammonium-mediated repression. Recent studies revealed that ammonium-tolerant nitrogen fixation in certain Paenibacillus species correlates with alanine overproduction mediated by alanine dehydrogenase (ADH) encoded by the ald gene. This study establishes a dual regulatory mechanism governing ald expression in P. polymyxa WLY78. The transcription activator AdeR positively regulates ald expression, while the global nitrogen regulator GlnR exerts repression on both ald and its activator gene adeR. Under high ammonium conditions, GlnR-mediated suppres

SUBMITTER: Zhang H 

PROVIDER: S-EPMC12369066 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature