9 research outputs found
Evaluation of an in silico predicted specific and immunogenic antigen from the OmcB protein for the serodiagnosis of Chlamydia trachomatis infections
<p>Abstract</p> <p>Background</p> <p>The OmcB protein is one of the most immunogenic proteins in <it>C. trachomatis </it>and <it>C. pneumoniae </it>infections. This protein is highly conserved leading to serum cross reactivity between the various chlamydial species. Since previous studies based on recombinant proteins failed to identify a species specific immune response against the OmcB protein, this study evaluated an <it>in silico </it>predicted specific and immunogenic antigen from the OmcB protein for the serodiagnosis of <it>C. trachomatis </it>infections.</p> <p>Results</p> <p>Using the ClustalW and Antigenic programs, we have selected two predicted specific and immunogenic regions in the OmcB protein: the N-terminal (Nt) region containing three epitopes and the C-terminal (Ct) region containing two epitopes with high scores. These regions were cloned into the PinPoint Xa-1 and pGEX-6P-1 expression vectors, incorporating a biotin purification tag and a glutathione-S-transferase tag, respectively. These regions were then expressed in <it>E. coli</it>. Only the pGEX-6P-1 has been found suitable for serological studies as its tag showed less cross reactivity with human sera and was retained for the evaluation of the selected antigens. Only the Ct region of the protein has been found to be well expressed in <it>E. coli </it>and was evaluated for its ability to be recognized by human sera. 384 sera were tested for the presence of IgG antibodies to <it>C. trachomatis </it>by our in house microimmunofluorescence (MIF) and the developed ELISA test. Using the MIF as the reference method, the developed OmcB Ct ELISA has a high specificity (94.3%) but a low sensitivity (23.9). Our results indicate that the use of the sequence alignment tool might be useful for identifying specific regions in an immunodominant antigen. However, the two epitopes, located in the selected Ct region, of the 24 predicted in the full length OmcB protein account for approximately 25% of the serological response detected by MIF, which limits the use of the developed ELISA test when screening <it>C. trachomatis </it>infections.</p> <p>Conclusion</p> <p>The developed ELISA test might be used as a confirmatory test to assess the specificity of serological results found by MIF.</p
Isolation and Characterization of Hydrocarbon-Degrading Yeast Strains from Petroleum Contaminated Industrial Wastewater
Two yeast strains are enriched and isolated from industrial refinery wastewater. These strains were observed for their ability to utilize several classes of petroleum hydrocarbons substrates, such as n-alkanes and aromatic hydrocarbons as a sole carbon source. Phylogenetic analysis based on the D1/D2 variable domain and the ITS-region sequences indicated that strains HC1 and HC4 were members of the genera Candida and Trichosporon, respectively. The mechanism of hydrocarbon uptaking by yeast, Candida, and Trichosporon has been studied by means of the kinetic analysis of hydrocarbons-degrading yeasts growth and substrate assimilation. Biodegradation capacity and biomass quantity were daily measured during twelve days by gravimetric analysis and gas chromatography coupled with mass spectrometry techniques. Removal of n-alkanes indicated a strong ability of hydrocarbon biodegradation by the isolated yeast strains. These two strains grew on long-chain n-alkane, diesel oil, and crude oil but failed to grow on short-chain n-alkane and aromatic hydrocarbons. Growth measurement attributes of the isolates, using n-hexadecane, diesel oil, and crude oil as substrates, showed that strain HC1 had better degradation for hydrocarbon substrates than strain HC4. In conclusion, these yeast strains can be useful for the bioremediation process and decreasing petroleum pollution in wastewater contaminated with petroleum hydrocarbons
Oil quality parameters and quantitative measurement of major secoiridoid derivatives in Neb Jmel olive oil from various Tunisian origins using qNMR
BACKGROUND: Olive oil contains compounds with interesting biological
activities which are influenced by the cultivar, the geographic origin
and other factors. The aims of this work were to (1) investigate these
factors in Neb Jmel olive oil from various Tunisian origins; (2)
determine the influence of geographic conditions on phenolic composition
of Neb Jmel olive oil and consequently on the antioxidant compounds; and
(3) verify whether oils could be discriminated based on geographical
origin.
RESULTS: The characterisation of extra-virgin Neb Jmel olive oil
produced in its original location has been conducted. Owing to the
effect of the genotype and environmental, agronomic and technological
factors on the chemical composition of olive oil and its quality, all
studied olives were collected at the same season, and their oil obtained
under the same processing technique. Many analyses were carried out to
characterise the different olive oils: free acidity, peroxide value,
fatty acid composition, Rancimat assay, pigments content and phenolic
compounds by H-1 NMR. A recently developed method for the direct
measurement of the oleocanthal and oleacein levels in olive oil by
quantitative H-1 NMR was applied. The method was applied to the study of
four Neb Jmel olive oils samples, and a broad variation of
concentrations of all four secoiridoids was recorded. The concentration
of each ranged from 55 to 529 mg kg(-1) and the sum of the four major
secoiridoids (known as D3) ranged from 436 to 1063 mg kg(-1).
CONCLUSION: The quantification of major phenolic compounds of olive oil
by NMR indicated that environmental conditions influence the production
of qualitative phenolic fractions. All these compounds can be used as
base `markers' to characterise and differentiate these olive oil on
geographic origin. (C) 2016 Society of Chemical Industr
Impact of Wastewater Spreading on Properties of Tunisian Soil under Arid Climate
The environmental impacts of irrigating an olive field with olive mill wastewater (OMW) and treated wastewater (TWW) on soil properties were investigated. The effect of different irrigation treatments of OMW (50 m3 ha−1, 100 m3 ha−1, and 200 m3 ha−1) and TWW at different soil depths was studied. The obtained findings revealed that TWW application augmented soil pH; EC values; and P, K and Ca contents in all soil layers. However, Mg and Na concentrations, as well as organic matter content (OM), were proven to decrease with TWW irrigation throughout the experiment. Whereas soil adjusted with OMW showed a decrease in K, Ca, Mg and Na contents with soil depth, a significant increase was observed with the increase in applied OMW dose. On the other hand, total phenols and OM content increased significantly with the rise in OMW levels in all the investigated layers compared to the control sample
Impact of Wastewater Spreading on Properties of Tunisian Soil under Arid Climate
The environmental impacts of irrigating an olive field with olive mill wastewater (OMW) and treated wastewater (TWW) on soil properties were investigated. The effect of different irrigation treatments of OMW (50 m3 ha−1, 100 m3 ha−1, and 200 m3 ha−1) and TWW at different soil depths was studied. The obtained findings revealed that TWW application augmented soil pH; EC values; and P, K and Ca contents in all soil layers. However, Mg and Na concentrations, as well as organic matter content (OM), were proven to decrease with TWW irrigation throughout the experiment. Whereas soil adjusted with OMW showed a decrease in K, Ca, Mg and Na contents with soil depth, a significant increase was observed with the increase in applied OMW dose. On the other hand, total phenols and OM content increased significantly with the rise in OMW levels in all the investigated layers compared to the control sample