Role of the Dihydrodipicolinate Synthase DapA1 on Iron Homeostasis During Cyanide Assimilation by the Alkaliphilic Bacterium Pseudomonas pseudoalcaligenes CECT5344

Abstract

Olaya-Abril et al. Cyanide Assimilation and Iron Homeostasis homeostasis response, which is mediated by the ferric uptake regulator Fur. DapA1 is required to produce dipicolinates that could act as iron chelators, conferring protection against oxidative stress and allowing the regeneration of Fe-S centers to reactivate cyanide-damaged metalloproteins.

Alternative Pathway for 3-Cyanoalanine Assimilation in Pseudomonas pseudoalcaligenes CECT5344 under Noncyanotrophic Conditions

“…4 ). Furthermore, similar results have been observed in a P. pseudoalcaligenes DapA − mutant that constitutively expresses the nitrilase nit4 gene from the promoter of the antibiotic resistance cassette inserted in this mutant ( 30 ).…”

“…4 ). On the other hand, a P. pseudoalcaligenes CECT5344 mutant in the dihydrodipicolinate synthase dapA gene, which is located upstream of nit4 in the cio gene cluster, also constitutively expresses the nitrilase Nit4 as consequence of the antibiotic resistance cassette used in the construction of this mutant ( 30 ). This DapA − mutant showed the same phenotype with 3-CNA as the sole N source as the MocR − mutant (not shown).…”

“…The NitC − and DapA − mutants were previously reported ( 7 , 30 ). Generation of the NitC − /Nit4 − and MocR − /Nit4 − double mutants was performed as described for Nit4 − but using the NitC − or MocR − mutant, respectively, as receptor strain, and selecting the transconjugants with gentamicin and kanamycin.…”

Beneficial Microorganisms to Control the Gray Mold of Grapevine: From Screening to Mechanisms

“…Enterobacter cloacae is perhaps best known as an opportunistic human pathogen that is commonly found in hospitals causing a wide range of infections, although some lineages have also been described as plant endophytes [ 49 ]. Indeed, several Enterobacter species can colonize internal plant tissues, improve plant growth and prevent from pathogens attacks [ 70 , 71 , 72 , 73 , 74 ]. Thus, Entrobacter cloacae was found to halt fungal phytopathogens growth such as Phytium debaryanum by 35.13% and Rhizoctonia solani with pathogen growth inhibition up to 60% [ 75 ].…”

“…The observed inhibition is due to production of several antifungal metabolites such as H 2 S, ammonia and volatile compounds such as phenylethyl alcohol, 4,5-dimethy l-1-hexene, and butyl acetate that halt the growth of fungal phytopathogens [ 50 , 76 ]. Recently, it has been reported that E. cloacae is able to produce inorganic volatile substances such as ammonia, IAA and hydroxamate siderophore, hydrogen cyanide and salicylic acid [ 74 , 77 ], in addition to chitinase, cellulase, and beta-glucosidase enzyme all of which may participate to the biocontrol activity [ 73 , 78 , 79 , 80 ]. Furthermore, Chaouachi et al [ 81 ] reported for the first time volatile organic compounds (VOCs) with antifungal activity produced by E. cloacae against B. cinerea decay on tomato fruit.…”