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

Abstract

Nitriles are organic cyanides with important industrial applications, but they are also found in nature. 3-Cyanoalanine is synthesized by plants and some bacteria to detoxify cyanide from endogenous or exogenous sources, but this nitrile may be also involved in other processes such as stress tolerance, nitrogen and sulfur metabolism, and signaling. The cyanide-degrading bacterium Pseudomonas pseudoalcaligenes CECT5344 grows with 3-cyanoalanine as the sole nitrogen source, but it does not use this nitrile as an intermediate in the cyanide assimilation pathway.

Proteomic Analysis of Arsenic Resistance during Cyanide Assimilation by Pseudomonas pseudoalcaligenes CECT 5344

“…Results obtained in the differential proteomic analysis CN vs. N presented a high degree of overlap with omic results previously described in this cyanide-degrading strain [ 39 , 41 , 43 , 44 ], thus supporting the robustness and reliability of the analysis. The four nitrilases (NitC, Nit4, Nit1, and Nit2) that are present in P. pseudoalcaligenes CECT 5344 [ 37 ] were identified in the proteomic analysis ( Table 1 ).…”

“…The four nitrilases (NitC, Nit4, Nit1, and Nit2) that are present in P. pseudoalcaligenes CECT 5344 [ 37 ] were identified in the proteomic analysis ( Table 1 ). As previously described, cyanide up-regulated the nitrilases NitC and Nit4, which are required for cyanide and 3-cyanoalanine assimilation, respectively [ 34 , 44 ]. NitC is encoded by the nitC (BN5_1632) gene of the nit1C cluster, whereas nit4 (BN5_1912) belongs to the cio gene cluster involved in the cyanide-insensitive respiration [ 37 ].…”

“…This nitrile is further hydrolyzed by the nitrilase NitC encoded by the nit1C gene cluster, generating ammonium used as a nitrogen source for growth [ 34 ]. The genome of this strain was completely sequenced [ 37 , 38 ], and omic studies on the cyanide assimilation were previously performed [ 39 , 40 , 41 , 42 , 43 , 44 ], making this bacterium a suitable model to develop system and synthetic biology strategies for bioremediation of residues co-contaminated with cyanide and arsenic [ 45 ]. Knowledge of the mechanisms involved in the resistance and detoxification of arsenic and cyanide is essential for the bioremediation of mining wastes and systems polluted with both contaminants.…”

Holistic view of biological nitrogen fixation and phosphorus mobilization in Azotobacter chroococcum NCIMB 8003

“…Protein concentration was estimated and 10 μL of the protein solution were digested with 2 μg trypsin overnight at 37°C without agitation. Finally, same amount of iRT (Biognosys) were added to all samples and 1 μg total protein was analyzed at the Research Support Central Service (SCAI), University of Cordoba, as previously described ( Olaya-Abril et al, 2021 ; Pérez et al, 2021 ). Then, MS2 spectra were searched by using MaxQuant software v2.2.0.0, with Andromeda as search engine against a database of A. chroococcum NCIMB 8003 deposited in Uniprot (UP000068210).…”

Bacterial tolerance and detoxification of cyanide, arsenic and heavy metals: Holistic approaches applied to bioremediation of industrial complex wastes

“…Conversely, omic techniques have been hardly applied to cyanide biodegradation up to date, and the application of systems and synthetic biology to cyanide bioremediation is at present merely an attractive proposal. Holistic analyses based on transcriptomics (Luque‐Almagro et al., 2015 ), regulation through small RNAs (Olaya‐Abril et al., 2019 ), and proteomics (Ibáñez et al., 2017 ; Olaya‐Abril et al., 2020 ; Pérez et al., 2021 ) of the degradation of sodium cyanide and/or cyanide‐containing jewellery residues have been only performed in P. pseudoalcaligenes CECT 5344, the first cyanide‐assimilating bacterium whose genome was completely sequenced (Luque‐Almagro et al., 2013 ; Wibberg et al., 2016 ). Systems and synthetic biology approaches could allow the improvement of the biodegradative capacities of this bacterial strain (Roldán et al., 2021 ).…”