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Öğe A novel Lactiplantibacillus plantarum strain: probiotic properties and optimization of the growth conditions by response surface methodology(Springer, 2024) Gokmen, Goekhan Gurur; Sariyildiz, Seda; Cholakov, Remzi; Nalbantsoy, Ayse; Baler, Biray; Aslan, Emek; Duzel, AhmetThe objective of this study is to explore the probiotic properties and optimal growth conditions of Lactiplantibacillus plantarum BG24. L. plantarum BG24 exhibited a remarkable ability to utilize lactose, and to grow under acidic conditions and in the presence of high levels of bile salts. The strain showed the highest antibacterial activity against L. monocytogenes Scott A (zone of inhibition: 26 mm). L. plantarum BG24 was found to be resistant to 8 of the tested 19 antibiotics using the disc diffusion method.and its multiple antibiotic resistance (MAR) index was calculated as 0.421. The adhesion rate to human intestinal epithelial Caco-2 cells was determined as 37.51%. The enzyme profile of L. plantarum BG24 was investigated using API ZYM test kit and the highest enzymatic activities were found for Leucine arylamidase, beta-glucosidase, Valine arylamidase, beta-galactosidase and N-acetyl-beta-glucosaminidase. L. plantarum BG24 strain showed higher microbial growth under static conditions (6.60 OD600) compared to 100 rpm (5.73 OD600) and 200 rpm (5.02 OD600) shaking speed due to its facultative anaerobic characteristic. However, different inoculation rates and glucose addition did not make a statistically significant difference on biomass formation (p > 0.05). The specific growth rate of L. plantarum BG24 was 0.416 h(-1), the doubling time was 1.67 h, and the biomass productivity value was 0.14 gL(-1) h(-1) in the original MRS broth (pH 5.7) while higher values were found as 0.483 h(-1), 1.43 h and 0.17 gL(-1) h(-1), respectively, in MRS broth (pH 6.5) medium enriched with 5 g/L yeast extract. The stirred tank bioreactor was used to optimise the growth of BG24 strain. The process variables was optimized at 0.05 vvm of aeration rate, 479 rpm of agitation speed, 3% of inoculation rate and 18 h of incubation time. The maximum biomass (g/L) production was obtained as 3.84 g/L at the optimized conditions.Öğe Optimization of culture conditions for the production and activity of recombinant xylanase from microalgal platform(Elsevier, 2023) Yildirim, Arzu; Ilhan-Ayisigi, Esra; Duzel, Ahmet; Mayfield, Stephen Patrick; Sargin, SaitXylanases are enzymes responsible for the hydrolysis of the heteropolymer xylan. They have wide applications ranging from the bakery, animal husbandry, and textile to pulp and paper industry and biofuel productions. Recombinant xylanase production has been previously reported from different hosts such as bacteria and yeast. Microalgae offer a safe and cost-effective photosynthetic platform for producing recombinant proteins, including therapeutics and industrial enzymes. In this study, we optimized the production of recombinant xylanase expressed and secreted from the green alga, Chlamydomonas reinhardtii. The growth of the culture was optimized using response surface methodology (RSM) based on central composite design (CCD), with two numeric (culture incubation time and agitation rate) and one categoric (light intensity) factors. The optimum biomass concen-tration was obtained as 0.71 mg/mL from the CCD values. In addition, bubble column photobioreactors were set and compared for the culture growth, the protein concentration, and the enzyme activity under different light intensities and air flows. Increasing the aeration rate from 1 vvm to 2 vvm resulted in improved enzyme activity from 5330.5 U/g to 6277.7 U/g under 3500 lux illumination on the 3rd day of the culture. This study may lead to the further large-scale production of xylanase with high enzyme activity and reveal the advantage of the microalgae as a sustainable platform.Öğe Production of xylanase intended to be used in bread-making: laboratory scale and pilot scale studies(Taylor & Francis Ltd, 2024) Ongen, Gaye Ongen; Sahinbas, Dilek; Duzel, Ahmet; Duzdemir, Gizem Ezgi; Altinel, Burak; Tuluk, Kubra; Sargin, SaitIn this study, submerged and solid-state fermentation studies were performed for xylanase production simultaneously to determine ideal carbon and nitrogen sources together with necessary production parameters from the laboratory scale to the pilot scale. The results showed that barley malt sprout is effective as a nitrogen and a good carbon source. Under optimum conditions, xylanase activities 71.74 +/- 2.70 U/mL, 56.95 +/- 3.6 U/mL, 65.8 +/- 8 U/mL and 46.05 +/- 0.1 U/mL were achieved in shake flasks, 2, 10 and 30 L bioreactors, respectively. In solid-state fermentation studies, maximum activity in flasks was 759.15 +/- 36.16 U/g production media, and maximum activity in pilot-scale tray bioreactor productions was 1312 +/- 137.85 U/g dry substrate. Bread-making trials showed that using xylanase at 100 U/100g flour resulted in a significant increase in the loaf volume of wheat flour bread and whole wheat flour bread.