Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - WoS: 15Citation - Scopus: 19Whey Protein-Pullulan (wp/Pullulan) Polymer Blend for Preservation of Viability of Lactobacillus Acidophilus(Taylor and Francis Ltd., 2015) Çabuk, Burcu; Harsa, Hayriye Şebnem; Harsa, ŞebnemIn this study, whey protein isolate-pullulan (WP/pullulan) microspheres were developed to entrap the probiotic Lactobacillus acidophilus NRRL-B 4495 by spray-drying technique. Microcapsules were analyzed for physicochemical characteristics including morphology, particle size, moisture content, water activity, dissolution time, and color properties. Results revealed that microcapsules were spherical in shape and obtained particle sizes between 5 and 160 µm, with an average size of around 50 µm. Blending pullulan with WP provided enhanced survival of probiotic bacteria during spray drying with a final viable cell number of 8.81 log CFU/g of microcapsule. Encapsulated probiotics were also found to have significantly (p ≤ 0.05) higher survived cell numbers compared to free probiotics under detrimental gastrointestinal conditions. Moreover, dissolution analysis suggested that protein-polysaccharide powdered microcapsules showed pH-sensitive dissolution properties in simulated gastric juice and simulated intestinal juice.Article Citation - WoS: 19Citation - Scopus: 22Optimization of the Associative Growth of Novel Yoghurt Cultures in the Production of Biomass, Ss-Galactosidase and Lactic Acid Using Response Surface Methodology(Elsevier Ltd., 2009) Tarı, Canan; Üstok, Fatma Işık; Harsa, Hayriye ŞebnemThe associative growth of Streptococcus thermophilus 95/2 (St 95/2) and Lactobacillus delbrueckii ssp. bulgaricus 77 (Lb 77) isolated from the Toros mountain region of Turkey was investigated with respect to lactic acid, biomass and β-galactosidase enzyme production using response surface methodology (RSM). The ratio (St 95/2:Lb 77) of the strains and media formulation had significant effect on all responses (p < 0.001). The predicted enzyme activity (2.14 U mL-1), lactic acid (22.50 g L-1) and biomass (7.11 g L-1) production at optimum conditions were very close to the actual experimental values (2.14 U mL-1, 22.94 g L-1 and 7.86 g L-1, respectively). The optimum conditions were to use these cultures in a ratio of 1.66:1.62 (St 95/2:Lb 77) in a medium containing whey (5%), corn steep liquor (4%), potassium phosphate (2%) and peptone (2%) at 43 °C for 8 h. The associative growth provided 6.4% and 39% more β-galactosidase activity and 8.73% and 44% more lactic acid compared with the results obtained using pure St 95/2 and Lb 77 strains, respectively.Article Citation - WoS: 16Citation - Scopus: 14Isolation and Characterization of Bacillus Thuringiensis Strains From Olive-Related Habitats in Turkey(John Wiley and Sons Inc., 2008) Çınar, Çelenk; Apaydın, Özgür; Yenidünya, Ali Fazıl; Harsa, Hayriye Şebnem; Güneş, HaticeAims: To isolate Bacillus thuringiensis strains from different olive-related habitats (olive groves and olive oil factories) in Turkey and to characterize these strains by molecular methods. Methods and Results: A total of 150 samples, consisting of olive grove soil, green olive leaves, olive leaf residues, animal faeces, olive pomace and dust, were examined for the presence of B. thuringiensis. One hundred B. thuringiensis strains were isolated from 54 environmental samples (36%) and characterized in terms of crystal morphology, cry and cyt gene content by polymerase chain reaction, plasmid profiles and 16S-internal transcribed spacer ribosomal DNA restriction fragment length polymorphism (16S-ITS rDNA RFLP). The highest percentage of samples containing B. thuringiensis was found in 38 out of 54 total soil samples (70%). Of the 100 B. thuringiensis isolates, the most frequent crystal shapes were irregularly shaped (24%), spherical-irregular pointed (19%), cuboidal (17%) and spherical (16%). The cry1 plus cry4 genotype was the most abundant genotype in our collection (21%). RFLP analysis of the amplified 16S-ITS rDNA revealed 11 distinct patterns for the isolates and 10 reference strains. Conclusions: Bacillus thuringiensis isolates showed a great genetic diversity and crystal shape heterogeneity. Significance and Impact of the Study: This is the first study on the isolation and characterization of B. thuringiensis from olive-related habitats in Turkey. No correlation was observed between the cry genotypes and insecticidal crystal shapes of the isolates. Restriction profiles of 23% of the isolates were found to be different from those of the 10 reference strains used.Article Citation - WoS: 21Citation - Scopus: 24Isolation and Characterization of Bacillus Thuringiensis Strains From Different Grain Habitats in Turkey(Springer Verlag, 2005) Apaydın, Özgür; Yenidünya, Ali Fazıl; Harsa, Hayriye Şebnem; Güneş, HaticeBacillus thuringiensis (Bt) is a gram-positive, spore-forming bacterium and it produces insecticidal crystal (cry) proteins during sporulation. Because the genetic diversity and toxic potential of Bt strains differ from region to region, strains have been collected and characterized all over the world. The aim of this study is to isolate Bt strains in grain-related habitats in Turkey and to characterize them on the basis of crystal morphology, cry gene content, and chromosomal and plasmid DNA profiles. Four approaches were taken analysis with phase contrast (PC) microscopy, polymerase chain reaction (PCR), pulsed field gel electrophoresis (PFGE) and plasmid isolation. Ninety-six samples were collected from Central Anatolia and the Aegean region. Bt was isolated from 61 of 96 samples (63.5) and 500 Bt-like colonies were obtained. One hundred and sixty three of the colonies were identified as Bt based on cry protein formation using PC microscopy. Among the examined colonies, the overall proportion identified (as Bt index) was 0.33. We found that 103 isolates were positive for the five different cry genes (cry1, cry2, cry3, cry4 and cry9) examined with PCR. In addition, plasmid profiling of 37 cry gene-positive isolates indicated that the 15 kb plasmid band was present in all isolates; however, 11 of 37 isolates had more than one plasmid band at different sizes. Finally, chromosomal DNA profiling by PFGE gave rise to different DNA patterns for isolates containing the same cry gene which suggests a high level of diversity among the Bt strains isolated.Article Citation - WoS: 7Citation - Scopus: 8Identification of Extracellular Enzyme Producing Alkalophilic Bacilli From Izmir Province by 16s-Its Rdna Rflp(John Wiley and Sons Inc., 2004) Akbalık, Güney; Güneş, Hatice; Yavuz, Elif; Yaşa, İhsan; Harsa, Hayriye Şebnem; Elmacı, Zehra Seda; Yenidünya, Ali FazılAims: To screen industrially important extracellular enzymes from the newly isolated alkalophilic bacilli and to characterize them by phenotypic and 16S-internal transcribed spacer (ITS) rDNA restriction pattern analysis. Methods and Results: Three different environmental samples, soil, leather and horse faeces, were collected within the province of Izmir. Isolates grown on Horikoshi-I medium for 24 h at 37°C were screened for extracellular enzyme activity by using eight different substrates: birchwood xylan, carboxymethylcellulose, casein, citrus pectin, polygalacturonic acid, soluble starch, and Tween 20 and 80. In total, 115 extracellular enzyme-producing bacilli were obtained. Casein was hydrolysed by 78%, soluble starch by 67%, citrus pectin by 63%, polygalacturonic acid by 62%, Tween 20 by 34%, birchwood xylan by 16%, Tween 80 by 12%, and carboxymethylcellulose by 3% of the isolates. The isolates were differentiated into 19 distinct homology groups by the 16S-ITS rDNA restriction pattern analysis. Conclusions: Eight different extracellular enzyme activities were determined in 115 endospore forming bacilli. The largest 16S-ITS rDNA homology group (HT1) included 36% of the isolates, 98% of which degraded casein, polygalacturonic acid, pectin and starch. Significance and Impact of the Study: This study is the first report on the characterization of the industrial enzyme-producing alkalophilic bacilli by 16S-ITS rDNA restriction fragment length polymorphism (RFLP). Restriction profiles of 64% of the isolates were found to be different from those of five reference strains used.Article Citation - WoS: 24Citation - Scopus: 25Identification of Extracellular Enzyme Producing Thermophilic Bacilli From Balcova (agamemnon) Geothermal Site by Its Rdna Rflp(John Wiley and Sons Inc., 2004) Yavuz, Elif; Güneş, Hatice; Harsa, Hayriye Şebnem; Yenidünya, Ali FazılAims: Molecular characterization of extracellular enzyme producing thermophilic bacilli from Balcova geothermal site. Methods and Results: Three types of geothermal samples were collected: mud, re-injection water, and samples from uncontrolled hydrothermal vents. Isolates grown at 55°C in culture media prepared in sterilized re-injection water, were screened for extracellular enzyme activity by using eight different substrates: casein, carboxymethyl-cellulose, pectin, polygalacturonic acid (PGA), soluble starch, Tween 20 and 80, and xylan. In total, 109 thermoaerophilic isolates were selected. All of the isolates could hydrolyse Tween 20 (100%) but not Tween 80. Soluble starch was hydrolysed by 96%, casein by 55%, xylan and carboxymethylcellulose by 9%, and pectin and PGA by 2% of the isolates. The isolates were grouped into 14 different homology groups by the restriction pattern analysis of 16S-internal transcribed spacer (ITS) rDNA RFLP. Each of the RFLP groups was also studied by 16S rRNA gene partial sequence analysis. Plasmid DNA profiles revealed that 15 of the isolated strains contained small plasmid DNA molecules ranging in size from 12 000 to 35 000 bp. Conclusions: Combined analysis of 16S-ITS rDNA RFLP and 16S rRNA gene partial sequence results indicated the presence of novel or existing species of Anoxybacillus (nine species) and Geobacillus (three species). Significance and Impact of the Study: In this study 16S-ITS rDNA RFLP was applied for the first time to differentiate thermophilic bacilli. It was also the first study on thermophilic bacilli of Balcova geothermal site.Article Citation - WoS: 17Citation - Scopus: 20Rflp of 16s-Its Rdna Region To Differentiate Lactobacilli at Species Level(Springer Verlag, 2004) Yavuz, Elif; Güneş, Hatice; Bulut, Çisem; Harsa, Hayriye Şebnem; Yenidünya, Ali FazılThe 16S-ITS (internal transcribed spacer) region of the rrn operon was amplified by polymerase chain reaction (PCR). The amplification products were analysed by restriction fragment length polymorphism (RFLP) using a set of restriction enzymes, AluI, HaeIII, and TaqI. Restriction pattern analyses revealed that TaqI restriction enzyme could clearly differentiate the nine reference strains of Lactobacillus used in the study.Article Citation - WoS: 3Citation - Scopus: 3Optimization of Pulsed Field Gel Electrophoresis (pfge) Conditions for Thermophilic Bacilli(Springer Verlag, 2004) Yavuz, Elif; Güneş, Hatice; Harsa, Hayriye Şebnem; Bulut, Çisem; Yenidünya, Ali FazılAlthough thermophilic members of the genus Bacillus are known to tolerate extreme environmental conditions, they appeared to be readily damaged upon mechanical manipulations. This fact was evidenced in genotyping of some strains of thermophilic Bacillus by pulsed field gel electrophoresis (PFGE). Consequently, a new procedure for the preparation of agarose plugs was developed. The procedure produced interpretable genomic DNA restriction profiles.Article Citation - WoS: 7Citation - Scopus: 6Chromatographic Separation of Amyloglucosidase From the Mixtures of Enzymes(Elsevier Ltd., 2001) Harsa, Hayriye Şebnem; Furusaki, ShintaroAn affinity chromatographic separation of amyloglucosidase (AMG) enzyme using β-cyclodextrin-chitosan matrix was investigated in this study. The adsorbent selectively adsorbed AMG from the mixtures of enzymes (lactase and α-amylase), and this selectively bound AMG was eluted from the column in two steps with a recovery yield of about 72%. A small fraction of AMG and other contaminating proteins did not bind to the column specifically and were eluted easily. Purified AMG was visualised on the sodiumdodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) experiments