Isolation and Characterization of a PEG-degrading and Mo-reducing Escherichia coli strain Amr-13 in soils from Egypt

Molybdenum is a pollutant that shows toxicity to spermatogenesis while polyethylene glycols (PEG) are used predominantly in detergents. The pollution of molybdenum and PEGs are reported worldwide. We have isolated ten molybdenum-reducing bacterial isolates from soil that can reduce molybdenum (sodium molybdate) into the colloidal molybdenum blue (Mo-blue). The screening of these isolates for PEG-degrading ability showed that one isolate was capable to utilize PEG 200, 300 and 600 for optimal conditions were pHs between 5.5 and 8.0, temperatures between 30 and 37 oC, phosphate at 5 mM, molybdate between 10 and 30 mM, and glucose as the electron donor. Biochemical analysis of the bacterium identifies it as Escherichia coli strain Amr-13. Growth was best supported by all PEGs at concentrations of between 600 and 1,000 mg/L. A complete degradation for PEG 200 and PEG 300 at 1,000 mg/L was observed on day four and five, respectively, while nearly 90% of PEG 600 was degraded on day six. The growth of this bacterium on these PEGs was modelled using the modified Gompertz model, and produced growth parameters values, which were maximum specific growth rates of 1.51, 1.45 and 1.18 d-1 and lag periods of 0.53, 0.87 and 1.02 day for PEG 200, PEG 300 and PEG 600, respectively. PEG 200 was the most preferred substrate for this bacterium, while PEG 600 was the least preferred.

Kinetics Modeling on the Biosorption of Remazol Black B Dye by Aspergillus flavus

Azo dyes, such as Remazol Black B, are different from conventional dyes in that they establish covalent bonds with textile fibers like cotton. They are widely utilized in the textile industry because of their favorable properties of bright color, water resistance, simple application procedures, and low energy consumption. Their discharge into receiving streams has major environmental consequences, such as reducing photosynthesis in aquatic life due to lower light penetration. The biosorption isotherm data of Remazol Black B dye biosorption by Aspergillus flavus were investigated using two models—pseudo-1st order and pseudo-2nd order—and fitted using non-linear regression. The pseudo-1st order model was found to be the best by statistical analysis using root-mean-square error (RMSE), adjusted coefficient of determination (adjR2), bias factor (BF), accuracy factor (AF), corrected AICc (Akaike Information Criterion), Bayesian Information Criterion (BIC), and Hannan–Quinn information criterion (HQC). At 250 mg/L, kinetic analysis using the pseudo-1st order model yielded an equilibrium sorption capacity qe of 4.61 mg/g (95 % confidence interval from 4.54 to 4.68) and a pseudo-1st-order rate constant, k1 of 0.15 (95% C.I. from 0.128 to 0.164).

Characterization of Butachlor Degradation by A Molybdenum-Reducing and Aniline-degrading Pseudomonas sp.

Butachlor is a chloroacetanilide herbicide that is selective in action and commonly used for pre-emergence control of weeds. It is believed to have range of toxicity from acute to chronic and also can cause DNA strand breaks and chromosomal aberrations in humans. This study was aimed at characterizing the potential of previously isolated bacteria for butachlor degradation. The isolates from culture collection, labelled A-F were screened for butachlor degradation on Bushnell Hass agar media with butachlor as a sole carbon source. Isolate A (molybdenum-reducing and aniline-degrading Pseudomonas sp.) was observed to grow best and tolerated the highest concentration of butachlor supplemented in the media after 72 h of incubation at 37 ℃. Characterization study revealed that the Pseudomonas sp. can utilize and grow with butachlor at optimum pH between 6.0 - 6.5, temperature between 30 – 37 ℃ and can tolerate up to 600 mg/L butachlor concentration with increase in growth as inoculum size increases. Additionally, this bacterial strain shows no lag phase regardless of the concentration of the herbicide used and reach its maximum growth after 24 h of incubation. The ability of this isolate to tolerate and utilize butachlor as sole carbon source makes it suitable for future bioremediation of this toxicant.

Kinetics Modelling of Pseudomonas stutzeri strain DN2 Growth Behaviour in Tributyltin Chloride

A predictive model was performed to describe Pseudomonas stutzeri strain DN2 growth behaviour in tributyltin chloride, using primary Modelling and a polynomial model as a secondary predictive model. In this investigation, data predicted using the modified Logistic (ML) was the most accurate. The Bias Factor (Bf) and Accuracy Factor (Af) values for the (ML) model were 1.39 and 1.51, indicating that the predictions were within a reliable range. The low RMSE value of 0.14, R2 and adj R2 (0.99) value closer to 1, showing that modified logistics is better than the other models at describing the growth behaviour of Pseudomonas stutzeri strain DN2 in toxic tributyltin chloride. Both the Aiba and Haldane models on the other hand, among the secondary model best fit the behaviours having low RMSE and MSE values and adjR2 value closer to 1. In this study, the primary and secondary kinetics of Pseudomonas stutzeri strain DN2 growth behaviour in tributyltin chloride was explored and it was shown in this study that the modified logistic and the Haldane models better suit the growth behavior of Pseudomonas stutzeri strain DN2 in tributyltin chloride. The parameters obtained from the modelling exercise will be very valuable in transferring the laboratory results to the field.

Effects of Nigerian Walnut (Juglan nigra) Lectin on Haematological Parameters and Lethal Dose (LD50) on Swiss Wistar

This study was designed to investigate the effects of Juglan nigra lectin on haematological parameters and lethal dose of rats. An authenticated Juglan nigra (UBHP401) collected from Lokoja was used to extract lectin and treated on Swiss Wistar rats (n=35) and (n=17) with weights from 75-129g for haematological parameters and LD50 respectively. The Wistar rats were divided into five equal groups labeled A, B, C, D, and E. Lectin concentrations were prepared and administered at stipulated days. Group A served as control, group B received 30%, C received 50%, D received 70% and group E received 90% of lectin intraperitoneally. Samples (Baseline-BL, First Harvests-FH and Second Harvest-SH) were collected from all the groups and analyzed for the following haematological parameters: white blood count (WBC), Red Blood count (RBC), Haemoglobin (HB), packed cell volume (PCV), platelet count, neutrophil, lymphocyte, monocytes, eosinophil and basophil. The data were analysed using two-way analysis of variance (ANOVA) in graph pad prism version 5.03. The Eosinophil count and white blood cell count were significantly increased P<0.005 and 0.05, whereas the HB, PCV and RBC showed significant different P<0.05 based on the day of exposure of the animal to the lectin, the platelet count was significantly increased on the basis of days of exposure of P<0.05, Eosinophil significantly increased too. Juglan nigra, (Nigerian walnut) Lectin is nontoxic as noted from LD50 result. Nigerian walnut lectin has a positive effect in haematopoietic activity of Swiss Wistar rats.

Isothermal Modelling of the Adsorption of Chromium onto Calcium Alginate Nanoparticles

Because of its extensive usage in industrial applications such as leather tanning, metallurgy, electroplating, and refractory materials, chromium is one of the most dangerous trace elements introduced into surface and ground waters. The sorption isotherm of chromium sorption onto calcium alginate nanoparticles were analyzed using ten models—Henry, Langmuir, Dubinin-Radushkevich, Freundlich, BET, Toth, Sips, Fritz-Schlunder IV, Baudu and Fritz-Schlunder V, and fitted using non-linear regression. Only the Toth and Fritz-Schlunder V models were unable to fit the data. Statistical analysis based on root-mean-square error (RMSE), adjusted coefficient of determination (adjR2), bias factor (BF), accuracy factor (AF), corrected AICc (Akaike Information Criterion), BIC and HQC showed that the Langmuir model was the best model in terms of overall best criteria. The calculated evidence ratio was 7 with an AICc probability value of 0.87 indicating that the best model was at least 7 times better than the nearest best model, which was Freundlich. The calculated Langmuir parameters qmL value of 79.174 mg/g (95% confidence interval from 50.702 to 107.646) and bL value of 0.332 L/mg (95% confidence interval from 0.294 to 0.371) is not much different from the linearized published work for the qmL value of 145 mg/g but lower than the bL value of 0.34 L/mg. The nonlinear regression method allows for the parameter values to be represented in the 95% confidence interval range which can better allow comparison with published results.

Detection Limit of the Four-Parameter Logistic Model for the Quantitative Detection of Serum Squamous Cell Carcinoma Antigenin Cervical Cancer Based on Surface Plasmon Resonance Biosensor

Biochemical diagnostic procedures, such as protein binding, rely on biomolecular interactions as its diagnostic modality, and as a consequence, their calibration curves are more complex. In addition, sigmoidal curves are often seen in these tests. In the event of asymmetry, a logistic (5PL) curve, or a logistic (4PL) curve, may be the best way to represent a distinctive sigmoidal relationship. It is possible that the linearization of an otherwise nonlinear connection by log transformation may result in a disruption of the error structure of the curve, and that this will have the opposite effect of decreasing or even eliminating error in the relationship. Previously, a surface plasmon resonance biosensor for the detection of squamous cell carcinoma antigen (SCCa) using nanoparticle technology was developed. However, based on the calibration curve, it conforms to the majority on sigmoidal shape curve for antibody-type sensing system. The resultant curve showed a sigmoidal calibration curve but was not modelled according to any of the sigmoidal models available. The LOD value obtained through the 4PL modelling exercise based on the classical method was 0.255 pM (95% confidence interval of 0.167 to 0.379) while the pooled standard deviation (PSD) method yielded an LOD value of 0.035 pM (95% confidence interval of 0.011 to 0.067), which indicates that the PSD method was superior.

The Effect of High Dosage of Codeine-Containing Cough Syrup on Renal Function on Albino Rats

Codeine-containing cough syrup (CCS) is one of the most abused drugs in the world especially among the youths. However, there is need to study the nephrotoxic effect associated with oral administration of the drug and to ascertain its effect on the kidney. Consequently, understanding the renal abnormalities in chronic use of CCS will be crucial for effective development of interventions. This study assessed the nephrotoxic effect associated with oral administration of codeine-containing cough syrup (Tutolin with Codeine) in albino rats, using the level of creatinine, urea, sodium, potassium and chloride ions as biomarker in the serum of albino rats. The rats were administered orally with Tutolin and Codeine at a dose of 80mg/kg, 160mg/kg, 240 mg/kg and 320mg/kg body weight. After three weeks of oral administration of the syrup to all the groups, there was no difference (P> 0.05) in the levels of sodium ion, chloride ion and creatinine among all the study groups and levels of urea and potassium ion in the group administered with 80 mg/kg, 160 mg/kg and 240 mg/kg body weight of tutolin with codeine compared with the control. After three weeks of oral administration of 80 mg/kg, 160 mg/kg, 240 mg/kg and 320 mg/kg body weight tutolin with codeine cough syrup, urea and potassium ion concentrations were higher (p<0.05) in group given 320mg/kg body weight of tutolin with codeine cough syrup compared with the control. This suggests that at higher doses, tutolin with codeine containing cough syrup may have effect on the kidney.