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.

Effect of chlorocholine chlorid on phenolic acids accumulation and polyphenols formation of buckwheat plants

BACKGROUND: Effect of chlorocholine chloride (CCC) on phenolic acids composition and polyphenols accumulation in various anatomical parts (stems, leaves and inflorescences) of common buckwheat (Fagopyrum esculentum Moench) in the early stages of vegetation period were surveyed. RESULTS: Treatment of buckwheat seeds with 2% of CCC has been increased content of total phenolics in the stems, leaves and inflorescences. On analyzing the different parts of buckwheat plants, 9 different phenolic acids - vanilic acid, ferulic acid, trans-ferulic acid, chlorogenic acid, salycilic acid, cinamic acid, p-coumaric acid, p-anisic acid, methoxycinamic acid and catechins were identified. The levels of identified phenolic acids varied not only significantly among the plant organs but also between early stages of vegetation period. Same changes as in contents of chlorogenic acid, ferulic acid, trans-ferulic acid were found for content of salycilic acid. The content of these phenolic acids has been significant increased under effect of 2% CCC treatment at the phase I (formation of buds) in the stems and at the phase II (beginning of flowering) in the leaves and then inflorescences respectively. The content of catechins as potential buckwheat antioxidants has been increased at the early stages of vegetation period after treatment with 2% CCC. CONCLUSIONS: The obtained results suggest that influence of CCC on the phenolics composition can be a result of various mechanisms of CCC uptake, transforming and/or its translocation in the buckwheat seedlings.

Ischemic preconditioning in the rat hippocampus increases antioxidant activities but does not affect the level of hydroxyl radicals during subsequent severe ischemia

Several studies have demonstrated that ischemic preconditioning increases superoxide dismutase activity, but it is unclear how ischemic preconditioning affects events downstream of hydrogen peroxide production during subsequent severe ischemia and reperfusion in the hippocampus. To answer this question, we investigated whether ischemic preconditioning in the hippocampal CA1 region increases the activities of antioxidant enzymes glutathione peroxidase and catalase, resulting in a decrease in the level of hydroxyl radicals during subsequent severe ischemia-reperfusion. Transient forebrain ischemia was induced by four-vessel occlusion in rats. Ischemic preconditioning for 3 min or a sham operation was performed and a 15-min severe ischemia was induced three days later. Ischemic preconditioning preserved the CA1 hippocampal neurons following severe ischemia. The concentration of 2,3-dihydroxybenzoic acid, an indicator of hydroxyl radical, was measured using in vivo microdialysis technique combined with HPLC. The ischemia-induced increase in the ratio of 2,3-dihydroxybenzoic acid concentration relative to baseline did not differ significantly between preconditioned and control groups. On the other hand, activities of the antioxidant enzymes glutathione peroxidase-1 and catalase were significantly increased at 3 days after ischemic preconditioning in the hippocampus. Our results suggest that, in preconditioned rats, while hydrogen peroxide is generated from severe ischemia, the activity of catalase and glutathione peroxidase-1 is correspondingly increased to eliminate the excessive hydrogen peroxide. However, our results show that the enhanced activity of these antioxidant enzymes in preconditioned rats is not sufficient to decrease hydroxyl radical levels during subsequent severe ischemia-reperfusion.

Degradation of 3-hydroxybenzoic acid by a Bacillus species.

A Bacillus sp. isolated by 4-hydroxybenzoate enrichment culture technique is capable of utilizing 3-hydroxybenzoate as the sole source of carbon and energy. The organism degraded 3-hydroxybenzoic acid through the intermediate formation of protocatechuic acid. 3-Hydroxybenzoate 4-hydroxylase, protocatechuate 3,4-dioxygenase and protocatechuate 4,5-dioxygenase activities were shown in cell-free extracts. The formed protocatechuate is metabolized through both the ortho and meta cleavage pathway.

Oxygen free radicals in idiopathic facial pain.

Chronic idiopathic oro-facial pain has become a common complaint, resulting increasingly in referral to the pain clinics world-wide, about 90% of the psychologically stress-related patients of the psychiatric clinic of Eastman Dental Hospital, London have been found to have associated idiopathic oro-facial pain. Psychological stress may produce a situation where oxidative stress might enhance the production of free radicals, especially OH radicals, in human biological fluids. Furthermore, it has been suggested that. OH radicals are responsible for the production of many systemic and local tissue injury diseases which may initially manifest as pain syndrome. It has been suggested that the oxygen free radical production of sailcloth, 2,3-dihydroxybenzoic acid (DHB) is a biological marker for the detection and quantification of OH radicals. Analyses of plasma samples collected from patients with chronic idiopathic orofacial pain and an equal number of age and sex matched control subjects revealed that the patient group had significantly increased evidence for circulating levels of 2,3-DHB after aspirin ingestion than control subjects. There was no significant difference in 2,5-DHB levels between the two groups. The urine samples from the same individuals showed evidence of measurable amounts of 2,3 and 2,5-DHB in both pre- and post-aspirin samples. These results suggest that OFRs may be involved in the aetiology of pain in patients that present with facial pain.