Browsing by Subject "FT-IR"

Now showing 1 - 4 of 4

Open Access
Fourier transform infrared spectroscopy as a novel approach for analyzing the biochemical effects of anionic surfactants on a surfactant-degrading acrobacter butzleri strain
(OSA Publishing, 2013-12-17) Sarioglu, O. F.; Tamer, Y. T.; Ozkan, A. D.; Atabay, H. I.; Molva, C.; Tekinay, T.
Anionic surfactant-biodegrading capability of an Arcobacter butzleri strain was analyzed under aerobic conditions. The A. butzleri isolate displayed efficient surfactant-biodegrading capacity for sodium dodecyl sulfate (SDS) at concentrations of up to 100 mg/L in 6 days, corresponding to 99.0% removal efficiency. Fourier transform infrared spectroscopy was applied to observe the effects of varying concentrations of SDS on the biochemistry of bacterial cells. Results suggest that protein secondary structures were altered in bacterial cells at sufficiently high SDS concentrations, concurrent with SDS biodegradation.
Open Access
Investigation of the crystallinity and orientation of polypropylene with respect to temperature changes using FT-IR, WRD, and Raman techniques
(2004) Türkçü, Harun Nezih
Having good mechanical and barrier properties, polypropylene films are widely used in food-packing industry. The relation of crystallinity and orientation of polypropylene with these properties are well known. Temperature increase has an important effect on the crystallinity and orientation of polypropylene. The purpose of this study is to understand better crystallinity and orientation changes of the cast and bi-axially oriented polypropylene films with respect to temperature effect. These changes were investigated using especially in-situ FT-IR and dichroism as well as XRD and Raman spectroscopy. For this purpose, an in-situ variable temperature set-up is developed and adapted for FT-IR studies. Accordingly, the changes in the peaks related to the amorphous and crystalline contents of the films as well as the peaks reflecting the orientation of the films were investigated over the temperature range from 120-170o C. Temperature cycle was also applied. Moreover, the films were investigated after application of additional stress at 120o C for various durations. The crystallinity and orientation of the films are affected significantly when the films were analyzed at higher temperature (>150o C). The crystallinity content of the film recovers after returning back to room temperature whereas orientational loss are permenant.
Open Access
Non-intercalative, deoxyribose binding of boric acid to calf thymus DNA
(Springer, 2014) Ozdemir, A.; Gursacli, R. T.; Tekinay, T.
The present study characterizes the effects of the boric acid binding on calf thymus DNA (ct-DNA) by spectroscopic and calorimetric methods. UV-Vis absorbance spectroscopy, circular dichroism (CD) spectroscopy, transmission electron microscopy (TEM), isothermal titration calorimetry (ITC), and Fourier transform infrared (FT-IR) spectroscopy were employed to characterize binding properties. Changes in the secondary structure of ct-DNA were determined by CD spectroscopy. Sizes and morphologies of boric acid-DNA complexes were determined by transmission electron microscopy (TEM). The kinetics of boric acid binding to calf thymus DNA (ct-DNA) was investigated by isothermal titration calorimetry (ITC). ITC results revealed that boric acid exhibits a moderate affinity to ct-DNA with a binding constant (K a) of 9.54x104 M -1. FT-IR results revealed that boric acid binds to the deoxyribose sugar of DNA without disrupting the B-conformation at tested concentrations. © 2014 Springer Science+Business Media.
Open Access
Production and structural characterization of biosurfactant produced by newly isolated staphylococcus xylosus STF1 from petroleum contaminated soil
(Elsevier BV, 2015) Keskin, N. O. S.; Han, D.; Ozkan A.D.; Angun, P.; Umu, O. C. O.; Tekinay, T.
Petroleum-contaminated soil was used to isolate and characterize biosurfactant producing bacteria. The strain could produce higher amount of biosurfactant in medium supplemented with motor oil as sole source of carbon and energy. A new biosurfactant producing bacterium, designated as Staphylococcus xylosus STF1 based on morphological, physiological, biochemical tests and 16S rRNA gene sequencing. The isolated bacterium was first screened for the ability to produce biosurfactant. Partial sequence of STF1 strain of 16S rDNA gene was highly similar to those of various members of the family Staphylococcaceae. Biochemical characterizations including FT-IR, Raman spectroscopy and Mass spectroscopy studies suggested the biosurfactant to be lipopeptide. Study also confirmed that the cell free supernatant exhibited high emulsifying activity against the different hydrocarbons. Moreover, the partially purified biosurfactant exhibited antimicrobial activity by inhibiting the growth of several bacterial species. The strain could be a potential candidate for the production of polypeptide biosurfactant which could be useful in a variety of biotechnological and industrial processes, particularly in the food and oil industry. © 2015 Elsevier B.V.