Production and Characterization of a Nitrilase from Pseudomonas aeruginosa RZ44 and its Potential for Nitrile Biotransformation

Abstract

Background The conversion of nitriles into amides or carboxylic acids by nitrilase has taken its application into consideration, as the scope of its applications has recently been extended. Objectives In this study, P. aeruginosa RZ44 was isolated from sewage in the Kerman which has Nitrile-degradation activity. In order to improve the nitrilase production, several optimization were done on environmental condition. Nitrilase activity was characterized against different pHs, temperatures, ions, and substrates. Materials and Methods Enzyme activity was evaluated by determining the production of ammonia following to the modification of the phenol/hypochlorite method. Different factors that affect production of the enzyme by P. aeruginosa RZ44 were optimized and evaluated in the culture mediums. Results The results showed that degradation of the acetonitrile by P. aeruginosa RZ44 increased the pH of the growth medium from the initial pH 7.0 to 9.37. Optimizing the medium for P. aeruginosa RZ44, it was found that glucose and starch (5 g.L-1) have strongly supported nitrilase production, compared to the control. As well, urea (5 g.L-1) and yeast extract (15 g.L-1) have favored an increased biomass and nitrilase production, as the nitrogen sources. These results show that nitrilase production increases in the pH range 5.0 to 7.0 and then start decreasing. Addition of the Mg2+, Fe2+ and Na+ has supported the biomass and nitrilase production. Co2+, Mn2+ and Cu2+ were confirmed to inhibit cell growth and enzyme production. Enzyme characterization results show that, P. aeruginosa RZ44 nitrilase exhibits comparatively high activity and stability at pH 7.0 and 40°C. Nitrilase was completely inhibited by CoCl2 and CaCl2, whereas, the inhibition in the presence of MnSO4 and CuSO4 was about 60%. Time course analysis of the nitrile conversion by the resting P. aeruginosa RZ44 cells showed that nitrile substrates (i.e. acetonitrile) was hydrolyzed within 8 h. Conclusions these results indicate that P. aeruginosa RZ44 has the potential to be applied in the biotransformation of nitrile compounds.

Biodegradation of Nitrile Gloves as Sole Carbon Source of Pseudomonas aeruginosa in Liquid Culture

“…The current literature lacks sufficient information concerning the degradability of NBR gloves and the ability of microorganisms to utilize them as a sole carbon source. Previous research studies have predominantly focused on rubber latex gloves, with limited attention given to nitrile gloves, as existing studies have focused on the monomer constituents of polymers [ 14 , 15 , 16 , 17 , 18 , 19 , 20 ].…”

“…These enzymes provide functional groups, such as alcohols or carbonyls, and catabolize polymer-generating monomers, reducing their molecular weight. Nitrilase is the most reported degradation enzyme in P. aeruginosa for highly toxic nitriles in the environment [ 11 , 14 , 29 ]. These products can be incorporated into intracellular metabolism through β-oxidation and the tricarboxylic acid cycle, ultimately being mineralized as CO 2 or biosynthesizing products through different metabolic pathways [ 25 , 30 ].…”

“…Nawong et al [ 20 ] conducted a study investigating the weight loss of rubber latex gloves (0.6%, w / v ) over a one-month period using individual cultures, revealing weight losses ranging from 0.5% to 9%. Badoei-Dalfard et al [ 14 ] conducted research utilizing nitrilase from P. aeruginosa RZ44 to biotransform acrylonitrile at a concentration of 5 mM. Shartooh et al [ 15 ] studied the biodegradation ability of P. aeruginosa utilizing acrylonitrile, and their findings revealed that the optimum concentration for biodegradation was 500 ppm, with the best adaptation period being 7 days.…”

Compendium-Wide Analysis of Pseudomonas aeruginosa Core and Accessory Genes Reveals Transcriptional Patterns across Strains PAO1 and PA14

“…Clinical and environmental strains exhibit various capacities for biofilm formation ( 6 , 7 ), levels of antibiotic susceptibility ( 8 , 9 ), metabolic profiles ( 10 ), and differences in virulence factor production ( 11 ). Some strains can also perform biotransformations of xenobiotic compounds ( 12 , 13 ). This strain-level phenotypic diversity is reflected in its genetic diversity; the P. aeruginosa genome contains both conserved core genes and strain-specific accessory genes ( 14 , 15 ).…”

Compendium-wide analysis of P. aeruginosa core and accessory genes reveal more nuanced transcriptional patterns

“…Some strains can also perform environmental biotransformations, which are chemical modifications. 12,13 This Strain-level phenotypic diversity is reflected in its genetic diversity; the P. aeruginosa genome contains both conserved core genes and strain-specific accessory genes. 14,15 A phylogenetic analysis across 1,311 strains, using only core genes, divided P. aeruginosa strains into five major lineages 14 .…”