2,4,6-trinitrotoluene (TNT) degradation by Indiicoccus explosivorum (S5-TSA-19).

2,4,6-trinitrotoluene (TNT), a nitro-aromatic explosive commonly used for defense and several non-violent applications is contributing to serious environmental pollution problems including human health. The current study investigated the remediation potential of a native soil isolate, i.e., Indiicoccus explosivorum (strain S5-TSA-19) isolated from collected samples of an explosive manufacturing site, against TNT. The survivability of I. explosivorum against explosives is indirectly justified through its isolation; thus, it is being chosen for further study. At a TNT concentration of 120 mg/L within an optimized environment (i.e., at 30 °C and 120 rpm), the isolate was continually incubated for 30 days in a minimal salt medium (MSM). The proliferation of the isolate and the concentration of TNT, nitrate, nitrite, and ammonium ion were evaluated at a particular time during the experiment. Within 168 h (i.e., 7 days) of incubation, I. explosivorum co-metabolically degraded 100% TNT. The biodegradation procedure succeeded the first-order kinetics mechanism. Formations of additional metabolites like 2,4-dinitrotoluene (DNT), 2,4-diamino-6-nitrotoluene (2-DANT), and 2-amino-4,6-dinitrotoluene (2-ADNT), were also witnessed. TNT seems to be non-toxic for the isolate, as it reproduced admirably in TNT presence. To date, it is the first report of Indiicoccus explosivorum, efficiently bio-remediating TNT, i.e., a nitro-aromatic compound via different degradation pathways, leading to the production of simpler as well as less harmful end products. Further, at the field-scale application, Indiicoccus explosivorum may be explored for the bioremediation of TNT (i.e., a nitro-aromatic compound)-contaminated effluents.

Study on aerobic degradation of 2,4,6-trinitrotoluene (TNT) using Pseudarthrobacter chlorophenolicus collected from the contaminated site.

2,4,6-trinitrotoluene or TNT, a commonly used explosive, can pollute soil and groundwater. Conventional remediation practices for the TNT-contaminated sites are neither eco-friendly nor cost-effective. However, exploring bacteria to biodegrade TNT into environment-friendly compound(s) is an interesting area to explore. In this study, an indigenous bacterium, Pseudarthrobacter chlorophenolicus, strain S5-TSA-26, isolated from explosive contaminated soil, was investigated for potential aerobic degradation of TNT for the first time. The isolated strain of P. chlorophenolicus was incubated in a minimal salt medium (MSM) containing 120 mg/L TNT for 25 days at specified conditions. TNT degradation pattern by the bacterium was monitored at regular interval using UV-Vis spectrophotometry, high-performance liquid chromatography, and liquid chromatography mass spectrophotometric, by estimating nitrate, nitrite, and ammonium ion concentration and other metabolites such as 2,4-dinitrotoluene (DNT), 2-amino-4,6-dinitrotoluene (2-ADNT), and 2,4-diamino-6-nitrotoluene (2-DANT). It was observed that, in the presence of TNT, there was no reduction in growth of the bacterium although it multiplied well in the presence of TNT along with no considerable morphological changes. Furthermore, it was found that TNT degraded completely within 15 days of incubation. Thus, from this study, it may be concluded that the bacterium has the potential for degrading TNT completely with the production of non-toxic by-products and might be an important bacterium for treating TNT (i.e., a nitro-aromatic compound)-contaminated sites.

Association of Apical Periodontitis with Different Stages of Chronic Kidney Disease Measured by Glomerular Filtration Rate and Systemic Markers: An Observational Study.

INTRODUCTION: The aim of this study was to assess the prevalence and severity of apical periodontitis (AP) in subjects with different stages of chronic kidney disease (CKD) and its association with systemic markers. METHODS: In this cross-sectional study, 105 patients with CKD (n = 35 each in the early, predialysis, and hemodialysis groups) and 105 healthy controls were included. The prevalence, number of teeth with AP (endodontic burden [EB]), and the severity of AP were recorded. High- sensitivity C-reactive protein, blood urea, and serum creatinine levels were also recorded. Logistic regression was applied to determine the possible association between CKD and AP in the study population, and linear regression was performed to predict the effect of AP on systemic markers in CKD patients. RESULTS: AP in at least 1 tooth was found in 75.2% of CKD patients and 40.9% of the controls (P < .05). CKD patients were 4 times more likely to have AP than controls (P < .05; odds ratio = 3.954; 95% confidence interval, 2.09-7.45). EB and the severity of AP were also significantly higher in CKD patients than the healthy controls (P < .05). Although higher values of EB and severe AP were observed with the progression of disease, the difference was not significant. The severity of AP was significantly associated with an increase in serum creatinine, blood urea, and a decrease in estimated glomerular filtration rate (P < .05) in CKD patients. CONCLUSIONS: AP was significantly more prevalent in the CKD group. The association between the severity of AP and CKD markers suggests that AP could possibly alter the progression of CKD. However, these findings do not establish a cause-and-effect relationship.