- Email: [email protected]
Effect of temperature and time on lactic acid fermentation of a yoghurt–wheat flour mixture
Abstracts / Journal of Biotechnology 256S (2017) S17–S43
Improving expression of a recombinant lipase and its application for production of silage amaranth Anna Aleksandrovna Tolkacheva ∗ , Tatyana Vasilevna Sviridova, Dmitry Aleksandrovich Cherenkov, Olga Sergeevna Korneeva Department of Biochemistry and Biotechnology, Voronezh State University of Engineering Technologies, Voronezh, Russia E-mail address: [email protected] (A.A. Tolkacheva). Loss of nutrients during silage storage can be reduced by 25–30% using enzyme preparations. The fat content of amaranth is about 7%, so it is reasonable to use lipase in the process of amaranth ensilage. The production of highly active enzyme preparations from natural sources is an expensive and time-consuming process. The use of inexpensive and technological recombinant enzymes obtained by selection and cloning of target genes can be a solution to this problem. The bacterium B. subtilis 168 was chosen as the source of the lipase gene. Gene was isolated and cloned by inserting into the plasmid vector pET23b+. The lipase gene was expressed in E. coli C41. The optimal parameters of induction were determined: induction time is 2 hours; IPTG concentration is 0.5 mM. Purification of His-tagged recombinant lipase was conducted by gravity-flow chromatography using Ni-NTA agarose. Lipase activity was based on the spectrophotometric determination of liberated fatty acids using olive oil as substrate. Specific activity of recombinant lipase per gram of protein was 20 times higher than the activity of the native enzyme. Thereby the obtained enzyme can be used in the technology of ensilage amaranth to increase the feed conversion efficiency.
S25
64%, 66% and 65,44% for MK7, MK13, MK16, MK41, MK49 and MK72, respectively. Almost all of these strains exhibited resistance to ampicillin (10 g), chloramphenicol (30 g), gentamicin (10 g), erythromycin (15 g), kanamycin (30 g), penicillin (10 g), streptomycin (10 g), tetracycline (10 g) and vancomycin (30 g). Subsequently, in vitro and in vivo experiments on the influence of these strains on colon cancer will be performed. http://dx.doi.org/10.1016/j.jbiotec.2017.06.635 Effect of temperature and time on lactic acid fermentation of a yoghurt–wheat flour mixture Senol Ibanoglu, Esra Ibanoglu ∗ Department of Food Engineering, Gaziantep University, Gaziantep, Turkey E-mail address: [email protected] (E. Ibanoglu). A white wheat flour–yoghurt mixture was fermented by its indigenous microflora at different temperatures (20–40 ◦ C) and for different times (0–42 h). Response surface methodology was applied to find a quadratic equation showing the relationship between the pH and the acidity of the mixture and the fermentation time and temperature. Setting the first derivative of the quadratic equations to zero and solving for the time gives the duration of the lag phase period. When the temperature was increased from 20 to 40 ◦ C, the fermentation time to attain a pH of 4.0 was reduced by approximately 5 times from 24.1 to 5.2 h and the lag phase period (no net change in pH) was reduced from 19.8 to 3.6 h. The activation energy (Ea) was 10.4 J/mol. http://dx.doi.org/10.1016/j.jbiotec.2017.06.636
Acknowledgments The work was supported by the state task No. 40.4149.2017/PCh. http://dx.doi.org/10.1016/j.jbiotec.2017.06.634 Food & Feed Biotechnology
Structural and functional changes of ozone oxidized proteins Esra Ibanoglu, Hicran Uzun, Senol Ibanoglu ∗ Gaziantep University, Food Engineering Department, Gaziantep, Turkey E-mail address: [email protected] (S. Ibanoglu).
Determination of probiotic properties of some lactic acid bacteria isolated from human feces Munevver Kahraman 1,∗ , Aynur Gul Karahan 2 1
Faculty of Medicine, Medical Research Center, Akdeniz University, Turkey 2 Suleyman Demirel University, Faculty of Engineering, Department of Food Engineering, Turkey E-mail address: [email protected] (M. Kahraman).
In this study, probiotic potential of fifty-five strains of bacteria isolated from stool specimens of 12 healthy volunteers, with the age range 25–45 was investigated. Bacterial strains identified using MALDI Biotyper (Bruker Daltonic) included fifty-three lactic acid bacteria strains, as well as Methylobacterium organophilum and Streptomyces hirsutus. Along with their resistance to gastric acidity (pH 3.5) and bile salts (0.3%), exopolysaccharide production, antioxidant activity and antibiotic susceptibilities of these strains were also analyzed. Strains of Lactobacillus pentosus MK7, Lactobacillus curvatus MK13, Lactobacillus plantarum MK16, and Enterococcus faecium MK41, MK49, MK72 had pH and bile tolerance. In addition, these strains also showed exopolysaccharide production capability, as revealed by qualitative methods. Antioxidant activities, examined by DPPH method, were 64,4%, 71,2%, 62,1%,
Ozone causes protein–protein cross-linking and a range of amino acid side chain modifications. These structural modifications may result in change in functional properties of proteins such as solubility, foaming and emulsification. The present study investigates some functional and structural properties of ozone oxidized whey protein isolate and egg white proteins which have been extensively used in food products to improve textural, functional and sensory attributes. Ozone treatment of proteins was performed either in aqueous solutions or as gas ozonation of pure protein powders. A significant change was observed in the optical activity and in HPLC chromatograms of proteins. The solubility and emulsifying ability were influenced negatively. However, the foaming ability was enhanced extensively. Denaturation of proteins due to ozonation was also investigated by DSC, FTIR and SEM. The results of the present work might be useful to understand the behaviour of functional ingredients ranging from the situation where ozone is used for cold sterilisation of complex food systems to the case where ozone is used to improve the protein functionality. http://dx.doi.org/10.1016/j.jbiotec.2017.06.637
Improving expression of a recombinant lipase and its application for production of silage amaranth Anna Aleksandrovna Tolkacheva ∗ , Tatyana Vasilevna Sviridova, Dmitry Aleksandrovich Cherenkov, Olga Sergeevna Korneeva Department of Biochemistry and Biotechnology, Voronezh State University of Engineering Technologies, Voronezh, Russia E-mail address: [email protected] (A.A. Tolkacheva). Loss of nutrients during silage storage can be reduced by 25–30% using enzyme preparations. The fat content of amaranth is about 7%, so it is reasonable to use lipase in the process of amaranth ensilage. The production of highly active enzyme preparations from natural sources is an expensive and time-consuming process. The use of inexpensive and technological recombinant enzymes obtained by selection and cloning of target genes can be a solution to this problem. The bacterium B. subtilis 168 was chosen as the source of the lipase gene. Gene was isolated and cloned by inserting into the plasmid vector pET23b+. The lipase gene was expressed in E. coli C41. The optimal parameters of induction were determined: induction time is 2 hours; IPTG concentration is 0.5 mM. Purification of His-tagged recombinant lipase was conducted by gravity-flow chromatography using Ni-NTA agarose. Lipase activity was based on the spectrophotometric determination of liberated fatty acids using olive oil as substrate. Specific activity of recombinant lipase per gram of protein was 20 times higher than the activity of the native enzyme. Thereby the obtained enzyme can be used in the technology of ensilage amaranth to increase the feed conversion efficiency.
S25
64%, 66% and 65,44% for MK7, MK13, MK16, MK41, MK49 and MK72, respectively. Almost all of these strains exhibited resistance to ampicillin (10 g), chloramphenicol (30 g), gentamicin (10 g), erythromycin (15 g), kanamycin (30 g), penicillin (10 g), streptomycin (10 g), tetracycline (10 g) and vancomycin (30 g). Subsequently, in vitro and in vivo experiments on the influence of these strains on colon cancer will be performed. http://dx.doi.org/10.1016/j.jbiotec.2017.06.635 Effect of temperature and time on lactic acid fermentation of a yoghurt–wheat flour mixture Senol Ibanoglu, Esra Ibanoglu ∗ Department of Food Engineering, Gaziantep University, Gaziantep, Turkey E-mail address: [email protected] (E. Ibanoglu). A white wheat flour–yoghurt mixture was fermented by its indigenous microflora at different temperatures (20–40 ◦ C) and for different times (0–42 h). Response surface methodology was applied to find a quadratic equation showing the relationship between the pH and the acidity of the mixture and the fermentation time and temperature. Setting the first derivative of the quadratic equations to zero and solving for the time gives the duration of the lag phase period. When the temperature was increased from 20 to 40 ◦ C, the fermentation time to attain a pH of 4.0 was reduced by approximately 5 times from 24.1 to 5.2 h and the lag phase period (no net change in pH) was reduced from 19.8 to 3.6 h. The activation energy (Ea) was 10.4 J/mol. http://dx.doi.org/10.1016/j.jbiotec.2017.06.636
Acknowledgments The work was supported by the state task No. 40.4149.2017/PCh. http://dx.doi.org/10.1016/j.jbiotec.2017.06.634 Food & Feed Biotechnology
Structural and functional changes of ozone oxidized proteins Esra Ibanoglu, Hicran Uzun, Senol Ibanoglu ∗ Gaziantep University, Food Engineering Department, Gaziantep, Turkey E-mail address: [email protected] (S. Ibanoglu).
Determination of probiotic properties of some lactic acid bacteria isolated from human feces Munevver Kahraman 1,∗ , Aynur Gul Karahan 2 1
Faculty of Medicine, Medical Research Center, Akdeniz University, Turkey 2 Suleyman Demirel University, Faculty of Engineering, Department of Food Engineering, Turkey E-mail address: [email protected] (M. Kahraman).
In this study, probiotic potential of fifty-five strains of bacteria isolated from stool specimens of 12 healthy volunteers, with the age range 25–45 was investigated. Bacterial strains identified using MALDI Biotyper (Bruker Daltonic) included fifty-three lactic acid bacteria strains, as well as Methylobacterium organophilum and Streptomyces hirsutus. Along with their resistance to gastric acidity (pH 3.5) and bile salts (0.3%), exopolysaccharide production, antioxidant activity and antibiotic susceptibilities of these strains were also analyzed. Strains of Lactobacillus pentosus MK7, Lactobacillus curvatus MK13, Lactobacillus plantarum MK16, and Enterococcus faecium MK41, MK49, MK72 had pH and bile tolerance. In addition, these strains also showed exopolysaccharide production capability, as revealed by qualitative methods. Antioxidant activities, examined by DPPH method, were 64,4%, 71,2%, 62,1%,
Ozone causes protein–protein cross-linking and a range of amino acid side chain modifications. These structural modifications may result in change in functional properties of proteins such as solubility, foaming and emulsification. The present study investigates some functional and structural properties of ozone oxidized whey protein isolate and egg white proteins which have been extensively used in food products to improve textural, functional and sensory attributes. Ozone treatment of proteins was performed either in aqueous solutions or as gas ozonation of pure protein powders. A significant change was observed in the optical activity and in HPLC chromatograms of proteins. The solubility and emulsifying ability were influenced negatively. However, the foaming ability was enhanced extensively. Denaturation of proteins due to ozonation was also investigated by DSC, FTIR and SEM. The results of the present work might be useful to understand the behaviour of functional ingredients ranging from the situation where ozone is used for cold sterilisation of complex food systems to the case where ozone is used to improve the protein functionality. http://dx.doi.org/10.1016/j.jbiotec.2017.06.637