Further characterization of o-nitrobenzaldehyde degrading bacterium Pseudomonas sp: ONBA-17 and deduction on its metabolic pathway

A previously reported o-nitrobenzaldehyde (ONBA) degrading bacterium Pseudomonas sp. ONBA-17 was further identified and characterized. Based on results of DNA base composition and DNA-DNA hybridization, the strain was identified as P. putida. Its degradation effect enhanced with increase of inoculum amount and no lag phase was observed. Higher removal rate was achieved under shaking conditions. All tested ONBA with different initial concentrations could be completely degraded within 5 d. In addition, degradative enzyme(s) involved was confirmed as intra-cellular distributed and constitutively expressed. Effects of different compounds on relative activity of degradative enzyme(s) within cell-free extract were also evaluated. Finally, 2-nitrobenzoic acid and 2, 3-dihydroxybenzoic acid were detected as metabolites of ONBA degradation by P. putida ONBA-17, and relevant metabolic pathway was preliminary proposed. This study might help with future research in better understanding of nitroaromatics biodegradation.

Evolución clínica de pacientes chilenos con tirosinemia tipo I tratados con 2-(2-nitro-4-trifluorometilbenzoil)-1,3-ciclohexanediona (NTBC) / Clinical follow up of Chilean patients with tyrosinemia type 1 treated with 2-(2-nitro-4-trifluoromethylbenzoyl)-1,3-ciclohexanedione (NTBC)

Background: Tyrosinemia type I is an inborn error of metabolism due to deficiency of fumarilacetoacetase. Acute presentation is with liver failure, hypophosphatemic rickets and peripheral neuropathy. Chronic presentation is with visceromegaly and subclinical rickets. The most severe complications are hepatic cancer and acute neurological crises. Without treatment, tyrosinemia type 1 is fatal. In 1992 treatment for tyrosinemia type 1 with 2-(2-nitro-4-trifluoromethybenzoyl)-1,3-ciclohexanedione (NTBC) was proposed. A clinical response was reported in 90% of patients. In cases that did not respond, a successful liver transplantation was performed, reducing mortality to 5%. Aim: To report the follow up of 12 patients treated with NTBC. Patients and Methods: Review of clinical records of 12 Chilean cases treated with NTBC at the Instituto de Nutrición y Tecnología de los Alimentos (INTA) from January 2004 until June 2010. Results: In all patients, a rapid metabolic control was achieved. Two patients developed hepatocarcinoma. One of these patients died and one was successfully treated with liver transplantation. One patient died after receiving a liver transplantation. Nine patients have at present good liver function, but 2 had peripheral neuropathy due to late diagnosis and discontinuing NTBC treatment. Conclusions: Treatment with NTBC allows metabolic normalization in tyrosinemia type 1, prevents liver cirrhosis and hepatic cancer, improving survival rates and quality of life in the patients. Neonatal screening is essential for the early diagnosis of this treatable disease, that otherwise may be lethal.

Isolation and preliminary characterization of a o-nitrobenzaldehyde-degrading Alcaligenes sp. ND1 / Isolamento e caracterização preliminar de lcaligenes SP ND1 degradador de o-nitrobenzaldeido

This paper reports the isolation and characterization of a new o-nitrobenzaldehyde (ONBA)-degrading bacterium, Alcaligenes sp. ND1. ND1 degraded almost all ONBA (100 mg L-1) in M9 medium within 36 hours. The key enzyme(s) involved in the initial biodegradation was a constitutively intracellular enzyme(s). This bacterium has great potential utility for bioremediation.

Esse trabalho relata o isolamento e a caracterização de uma nova bactéria degradadora de o-nitrobenzaldeido (ONBA), Alcaligenes sp ND1. A bactéria ND1 decompôs todo o ONBA (100 mg.L-1) do meio M9 em 36 horas. A enzima-chave envolvida na biodegradação inicial foi uma enzima constitutiva intracelular. Esta bactéria apresenta um potencial de aplicação para bioremediação.