Bacterial catabolic genes (alkB, alkH, C12O, and C23O) are a good biomarker for choosing the choice of the organism for polycyclic aromatic hydrocarbon (PAH) degradation. Low molecular weight (LMW) and high molecular weight (HMW) PAHs metabolism can be made possible by monooxygenase and dehydrogenase enzymes which code for the catabolic genes. In this study, the monooxygenase and dehydrogenase genes were characterized from the bacterial population isolated from motor mechanic workshop soils and landfill soil artificially polluted with waste engine oil (WEO). Standard microbiological methods were followed for the isolation and characterization of the bacterial population. The PCR cycling for alkB and alkH followed initial denaturation at 94oC for 5 minutes, followed by 35 cycles of denaturation at 95oC for 1 minute, annealing at the correct temperature (alkB 49oC, alkH 72oC). PCR cycling for C12O and C23O genes followed initial denaturation at 95oC for 5 minutes, 35 cycles of denaturation at 94oC for 20 s, annealing at 63oC for 30 s, extension at 60oC for 45 s, with final extension for 5 minutes at 72oC. Final elongation step for all the catabolic genes at 72oC for 10 minutes and holding temperature at 10oC forever. Amplified fragments were visualized on safe view-stained 1.5% agarose gel electrophoresis. The result of the characterization revealed base pair sizes of the genes; alkB (100 to 300 bp), alkH (< 700 bp), C12O (>250 bp), and C23O (<80 pb). All the bacterial populations invested in this study expressed the monooxygenase and dehydrogenase genes. Monooxygenase and dehydrogenase genes are coding for the enzymes responsible for hydroxylation and intradiol or extradiol ring-cleaving of PAHs.
Sensitive vegetables grown in heavy metals polluted soils tend to accumulate heavy metals which are harmful to the human body even at low concentrations. In this study, the bioconcentration factor (Transfer Factor) was used to assess the accumulation of some heavy metals in Talinum triangulare grown in the vicinity of an automobile workshop in Oluku, Benin City. Physical and chemical parameters found to affect the interactions and mobility of heavy metals in the soil mass were also examined. A pH of 6.17±0.2 was obtained for the topsoil while the middle and bottom soil samples were 5.93±0.4 and 6.00±0.1 respectively, The values of CEC obtained for top, middle, and bottom soil samples were 5.58±0.54, 4.56±0.11, and 3.65±0.14 meq/100g respectively. Soil samples were randomly collected from three depths of 0-10 cm, 10-20 cm, and 20-30 cm with the aid of a soil auger; and T. triangulare were collected within the soil sampling locations. The concentrations of heavy metal were evaluated through the use of atomic absorption spectrophotometer after the samples were subjected to tri-acid digestion techniques. Particle size analysis showed that the soil is a sandy loam texture. High Transfer factor values were ascertained for some metals but none was greater than one. Therefore T. triangulare cannot be considered a hyperaccumulator of heavy metals investigated in this study. However, all metals found in T. triangulare were highly significant (p<0.05), and higher than the permissible limits recommended by FAO/WHO/EC/CODEX. Consumption of T. triangulare harvested from the vicinity of automobile workshops should be highly discouraged to avoid public health hazards.
Water quality, free/total chlorine (Cl2) and bacteriological standard, determine the shelf life of water in the hands of the consumers. This study was carried out to determine the free/total chlorine, coliform and heterotrophic bacterial profile of Polyethylene Terephthalate (PET) and sachet water sold within and around the University of Benin Campus. PET/sachet water was randomly sampled from sales vendors and transported to the laboratory in ice condition for analysis. Standard microbiological methods have followed the determination of the coliform and heterotrophic bacterial profile of the sampled water. The digital colorimeter methods with N, N Diethyl-P-Phenylene Diamine (DPD) pillow for free chlorine (DPD 1) and total chlorine (DPD 4) determination in water was used. The free chlorine from PET/sachet water samples of UNIBEN, Faithmark, Dandori and Olivia waters were > 0.1 mg/l, falling short of the recommended World Health Organization (WHO) and Center for Disease and Prevention (CDC) permissible limit (0.2 to 0.5 mg/l). The coliform bacterial counts from this study were recorded as <1.8 MPN, which is less than the WHO and CDC recommended permissible limit. Whereas, the Heterotrophic bacterial counts were well above the recommended limit (> 500 cfu/ml). A proper hygienic regime should be employed during the processing, packing, distribution and sales of PET/sachet water to eliminate high levels of heterotrophic bacteria, which may contaminate the water.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.