Food Engineering / Gıda Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/12
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Article Citation - WoS: 2Citation - Scopus: 2Improvement of Fermentable Sugar Extraction From Hazelnut Shells Through Microwave Assisted Dilute Acid Pretreatment(North Carolina State University, 2023) Uzuner, SibelThe most effective method for producing fermentable sugars (FSs) from biomass is thermochemical pretreatment assisted by enzymatic hydrolysis. However, the enzymatic hydrolysis-assisted thermochemical pretreatment method is limited by the formation of fermentation inhibitors, and it is time-consuming. There is growing interest in using a microwave (MW) pretreatment due to its uniform and rapid heating. This study aimed to determine, perform data-driven modeling, and optimize the effect of MW combined with dilute acid pretreatment (MW-DA) on the production of FSs from hazelnut shells. An artificial neural networks (ANNs) model based on Box-Behnken Design (BBD) was the best model described for fermentable sugar extraction (FSE). Optimization via BBD-based ANNs model was carried out for an acid concentration of 0.5 to 2% (w/w), a pretreatment time of 5 to 25 min, a pressure of 5 to 15 bar, and a temperature of 120 to 160 °C. The optimized FSE was estimated at 374 mg/g (81.4% conversion efficiency), with a severity factor of 3.61 under 1.58% H2SO4 for 13 min at 160 °C and 8.5 bar. Using the MW-DA pretreatment process lowered the costs significantly due to the decreases in acid concentration and pretreatment time.Article Citation - WoS: 12Citation - Scopus: 12Quantitative Real-Time Pcr Analysis of Bacterial Biomarkers Enable Fast and Accurate Monitoring in Inflammatory Bowel Disease(PeerJ Inc., 2022) Sezgin, Efe; Terlemez, Gamze; Bozkurt, Berkay; Bengi, Göksel; Akpınar, Hale; Büyüktorun, İlkerInflammatory bowel diseases (IBD) affect millions of people worldwide with increasing incidence. Ulcerative colitis (UC) and Crohn’s disease (CD) are the two most common IBDs. There is no definite cure for IBD, and response to treatment greatly vary among patients. Therefore, there is urgent need for biomarkers to monitor therapy efficacy, and disease prognosis. We aimed to test whether qPCR analysis of common candidate bacteria identified from a patient’s individual fecal microbiome can be used as a fast and reliable personalized microbial biomarker for efficient monitoring of disease course in IBD. Next generation sequencing (NGS) of 16S rRNA gene region identified species level microbiota profiles for a subset of UC, CD, and control samples. Common high abundance bacterial species observed in all three groups, and reported to be associated with IBD are chosen as candidate marker species. These species, and total bacteria amount are quantified in all samples with qPCR. Relative abundance of anti-inflammatory, beneficial Faecalibacterium prausnitzii, Akkermansia muciniphila, and Streptococcus thermophilus was significantly lower in IBD compared to control samples. Moreover, the relative abundance of the examined common species was correlated with the severity of IBD disease. The variance in qPCR data was much lower compared to NGS data, and showed much higher statistical power for clinical utility. The qPCR analysis of target common bacterial species can be a powerful, cost and time efficient approach for monitoring disease status and identify better personalized treatment options for IBD patients.Article Citation - WoS: 5Modeling Growth of Alicyclobacillus Acidoterrestris Dsm 3922 Type Strain Vegetative Cells in the Apple Juice With Nisin and Lysozyme(AIMS Press, 2017) Molva, Çelenk; Baysal, Ayşe HandanIn the present study, the effect of storage temperature on A. acidoterrestris DSM 3922 cells (105 CFU/mL) was examined during growth in reconstituted apple juice (pH 3.8, degrees Brix 11.3) containing nisin (0-100 IU/mL) and lysozyme (0-100 mg/L). The growth curves were obtained at three temperatures of 27, 35 and 43 degrees C using absorbance data (OD600nm). Based on the results, the minimal inhibitory concentrations (MICs) of nisin were found as 10 IU/mL at all tested temperatures. On the other hand, increasing the temperature decreased the amount of lysozyme for growth inhibition. The MICs of lysozyme were found as 10, 2.5 and 1.25 mg/L at 27, 35 and 43 degrees C, respectively. At selected non-inhibitory doses, nisin (1.25-5 IU/mL) and lysozyme (0.3-2.5 mg/L) prolonged the lag time compared to the controls at the corresponding temperatures. In addition, there was a strong linear relationship between the lag time and lysozyme concentrations at 27 and 35 degrees C (R-2 > 0.98). The results of this study demonstrated that both nisin and lysozyme could be used to inhibit the growth of A. acidoterrestris cells in the apple juice. The results also indicated that the growth parameters were variable depending on the storage temperature and the type of the antimicrobial agent used in the apple juice.Article Citation - WoS: 13Citation - Scopus: 13Macromolecular Changes in Nilotinib Resistant K562 Cells; an in Vitro Study by Fourier Transform Infrared Spectroscopy(SAGE Publications Inc., 2012) Ceylan, Çağatay; Camgöz, Aylin; Baran, YusufNilotinib is a second generation tyrosine kinase inhibitor which is used in both first and second line treatment of chronic myeloid leukemia (CML). In the present work, the effects of nilotinib resistance on K562 cells were investigated at the molecular level using Fourier transform infrared (FT-IR) spectroscopy. Human K562 CML cells were exposed to step-wise increasing concentrations of nilotinib, and sub-clones of K562 cells resistant to 50 nM nilotinib were generated and referred to as K562/NIL-50 cells. Antiproliferative effects of nilotinib were determined by XTT cell proliferation assay. Changes in macromolecules in parental and resistant cells were studied by FT-IR spectroscopy. Nilotinib resistance caused significant changes which indicated increases in the level of glycogen and membrane/lipid order. The amount of unsaturated lipids increased in the nilotinib resistant cells indicating lipid peroxidation. The total amount of lipids did not change significantly but the relative proportion of cholesterol and triglycerides altered considerably. Moreover, the transcriptional status decreased but metabolic turn-over increased as revealed by the FT-IR spectra. In addition, changes in the proteome and structural changes in both proteins and the nucleus were observed in the K562/NIL-50 cells. Protein secondary structural analyses revealed that alpha helix structure and random coil structure decreased, however, anti-parallel beta sheet structure, beta sheet structure and turns structure increased. These results indicate that the FT-IR technique provides a method for analyzing drug resistance related structural changes in leukemia and other cancer types.Article Citation - WoS: 14Citation - Scopus: 12Enhanced Production of Exo-Polygalacturonase From Agro-Based Products by Aspergillus Sojae(North Carolina University, 2011) Büyükkileci, Ali Oğuz; Tarı, Canan; Fernandez-Lahore, MarcelloAspergillus sojae has been previously shown to produce exo-polygalacturonase (exo-PG) in synthetic media, where the potential of the organism to utilize agricultural substrates was not considered so far. In this study, the utilization of agro-based products was taken into account in the enhanced production of exo-PG using an A. sojae mutant by applying statistical design methods. Complex sources (orange peel, wheat bran, and corn meal), simple sugar sources (glucose, maltrin, and sugar beet syrup), and two phosphate salts were screened using D-optimal design method. Orange peel yielded the highest exo-PG activity with all simple sugars and phosphate sources. According to the results of response surface methodology (RSM), the optimum concentrations of orange peel, sugar beet syrup, and (NH 4) 2SO 4 were found to be 10, 60, and 8 g L -1, respectively. The exo-PG activity under these conditions was 145.4 U m L -1 in shake flask cultures. In bioreactor studies enzyme production was induced at low pH values; thus highest production was obtained under uncontrolled pH conditions, in which the pH dropped to 2.0 in 72 h. As a result high exo-PG could be produced by an A. sojae mutant using a cost-effective medium containing agro-industrial substrates. Another important advantageous outcome was the low optimal pH, which is especially desired in industrial fermentations prone to contamination problems. In fact this highlights the easy adaptation of this fermentation to industrial scales.