- Email: [email protected]
Bioleaching as a method of zinc removal from copper-zinc sulfide concentrate
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Abstracts / Journal of Biotechnology 256S (2017) S44–S116
neu.edu.tr) for clinicians and researchers to trace the history of the Neanderthal allele and correlate with the persons’ phenotype. To conclude, our developed model will provide the better understanding for the origin of the genetic diseases or traits that are association with Neanderthal genome. Moreover, this precise medicine model will help the individuals and their belonged populations to receive the best treatment. Finally, it will be the strong answer of the question of why there are differences in disease phenotypes in modern humans. http://dx.doi.org/10.1016/j.jbiotec.2017.06.980 Bioprocess Engineering Bioleaching as a method of zinc removal from copper-zinc sulfide concentrate Maxim Muravyov ∗ , Natalya Fomchenko Laboratory of Chemolithotrophic Microorganisms, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russia E-mail address: [email protected] (M. Muravyov). Copper-zinc concentrates can be obtained from sulfide ores. Their production does not require expensive equipment but further separation of the concentrates to produce high-grade copper and zinc concentrates is associated with various difficulties and high costs. The development of methods for processing of collective sulfide concentrates by bioleaching is a relevant issue. The concentrate obtained at commercial concentrator contained 10.1% of copper, 7.36% of zinc, 36.1% of iron, and 34.5% of sulfur. Pyrrhotite, sphalerite, and chalcopyrite were the main sulfide minerals. Two consortia of acidophilic chemolithotrophic microorganisms, mesophilic (30 ◦ C) and moderately thermophilic (38 ◦ C), were developed to perform the experiments. Zinc was completely leached after 9 days of bioleaching by the moderately thermophilic consortium at pulp densities of 2 and 3%, whereas copper recovery was 18.2 and 20.3%, respectively. Bioleaching by the mesophilic consortium led to recovery of zinc equal to 94.6 and 83.8%, and copper of 13.4 and 11.4%, respectively. Selective leaching of zinc could be caused by galvanic interactions between minerals of the concentrate. The results on selective leaching of zinc made it possible to propose new approaches to copper-zinc sulfide concentrate processing. The study was supported by RFBR (15-08-03763 a) and by the Presidium of RAS (1.4P). http://dx.doi.org/10.1016/j.jbiotec.2017.06.981 Impact of immobilization techniques of brewing strain “Saccharomyces Cerevisiae” on fermentation kinetics Luljeta Pinguli 1,∗ , Ilirjan Malollari 1 , Rozana Troja 1 , Arjola Bacu 2 , Vilma Gurazi 1 , Terkida Vaso 1 1 Department of Industrial Chemistry, Faculty of Natural Sciences, University of Tirana, Tirana, Albania 2 Department of Biotechnology, Faculty of Natural Sciences, University of Tirana, Tirana, Albania
E-mail address: [email protected] (L. Pinguli). Our study was focused on comparing three different immobilized brewing yeast fermentation with traditional free cell fermentation in experimental scale. The immobilization techniques used were:
entrapment and encapsulation method in alginate and gel immobilization in gelatin support. Fermentation performances were analyzed based on fermentation rate parameters and yeast cell physiology. The kinetic fermentation parameters were studied by fitting the experimental data with four different kinetic models, Monod, Contois, modified Monod and Teisser. Encapsulated immobilized yeast fermentation was the closer one to the free cell fermentation. Due to the high diffusion inside the biocatalyst particles, inhibitory phenomena were avoided and the microbial activity was preserved. The vitality of the yeast cells, specific growth rate and the sugar uptake rate were directly related to the medium conditions and permeability of the immobilized capsule. Microscopic surveys of immobilized yeast cells, shows notable differences in cell growth performance of gelatin immobilization technique compared to free and two other immobilization techniques. Budding, pseudomycelium formation, vitality and contamination was better in entrapment and encapsulated immobilized yeast, compared to free cell suspension. http://dx.doi.org/10.1016/j.jbiotec.2017.06.982 Evaluation of hydrodynamic parameters and rheological behaviours for Haematococcus pluvialis production in stirred tank photobioreactor Bahar Aslanbay ∗ , Irem Deniz, Zeliha Demirel, Suphi Oncel, Esra Imamoglu Department of Bioengineering, Ege University, I˙ zmir, Turkey E-mail address: [email protected] (B. Aslanbay). Microalgae cultivation requires some specific conditions including temperature, light intensity, mixing, etc. They can be grown in an open system or in different type of closed photobioreactors depend on these conditions. Stirred tank photobioreactor is one of these systems and has common applications. The aim of this study was to cultivate a green microalga, Haematococcus pluvialis, in a stirred tank photobioreactor and to evaluate different hydrodynamic parameters. Firstly, microalgae were cultivated in BG11 culture medium with the mixing rate of 120 rpm in a 2 L stirred tank photobioreactor. Then, hydrodynamic parameters and rheological behaviors of culture medium were evaluated. The density and kinematic viscosity of the culture medium were 1018 kg/m3 and 5.89 × 10−6 m2 /s, respectively. The flow was in the turbulence region where the impeller Reynolds number was 9108.88 corresponding to the impeller tip speed of 1.99 m/s. Also, the specific growth rate of 0.22 day−1 was obtained at the end of the study. It was estimated that the reason of these slow cell growth was shear stress due to the mechanically stirring. The experiments on the evaluation of hydrodynamic parameters in stirred tank photobioreactor have given valuable information for the cultivation of H. pluvialis microalga and photobioreactor systems. http://dx.doi.org/10.1016/j.jbiotec.2017.06.983
Abstracts / Journal of Biotechnology 256S (2017) S44–S116
neu.edu.tr) for clinicians and researchers to trace the history of the Neanderthal allele and correlate with the persons’ phenotype. To conclude, our developed model will provide the better understanding for the origin of the genetic diseases or traits that are association with Neanderthal genome. Moreover, this precise medicine model will help the individuals and their belonged populations to receive the best treatment. Finally, it will be the strong answer of the question of why there are differences in disease phenotypes in modern humans. http://dx.doi.org/10.1016/j.jbiotec.2017.06.980 Bioprocess Engineering Bioleaching as a method of zinc removal from copper-zinc sulfide concentrate Maxim Muravyov ∗ , Natalya Fomchenko Laboratory of Chemolithotrophic Microorganisms, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russia E-mail address: [email protected] (M. Muravyov). Copper-zinc concentrates can be obtained from sulfide ores. Their production does not require expensive equipment but further separation of the concentrates to produce high-grade copper and zinc concentrates is associated with various difficulties and high costs. The development of methods for processing of collective sulfide concentrates by bioleaching is a relevant issue. The concentrate obtained at commercial concentrator contained 10.1% of copper, 7.36% of zinc, 36.1% of iron, and 34.5% of sulfur. Pyrrhotite, sphalerite, and chalcopyrite were the main sulfide minerals. Two consortia of acidophilic chemolithotrophic microorganisms, mesophilic (30 ◦ C) and moderately thermophilic (38 ◦ C), were developed to perform the experiments. Zinc was completely leached after 9 days of bioleaching by the moderately thermophilic consortium at pulp densities of 2 and 3%, whereas copper recovery was 18.2 and 20.3%, respectively. Bioleaching by the mesophilic consortium led to recovery of zinc equal to 94.6 and 83.8%, and copper of 13.4 and 11.4%, respectively. Selective leaching of zinc could be caused by galvanic interactions between minerals of the concentrate. The results on selective leaching of zinc made it possible to propose new approaches to copper-zinc sulfide concentrate processing. The study was supported by RFBR (15-08-03763 a) and by the Presidium of RAS (1.4P). http://dx.doi.org/10.1016/j.jbiotec.2017.06.981 Impact of immobilization techniques of brewing strain “Saccharomyces Cerevisiae” on fermentation kinetics Luljeta Pinguli 1,∗ , Ilirjan Malollari 1 , Rozana Troja 1 , Arjola Bacu 2 , Vilma Gurazi 1 , Terkida Vaso 1 1 Department of Industrial Chemistry, Faculty of Natural Sciences, University of Tirana, Tirana, Albania 2 Department of Biotechnology, Faculty of Natural Sciences, University of Tirana, Tirana, Albania
E-mail address: [email protected] (L. Pinguli). Our study was focused on comparing three different immobilized brewing yeast fermentation with traditional free cell fermentation in experimental scale. The immobilization techniques used were:
entrapment and encapsulation method in alginate and gel immobilization in gelatin support. Fermentation performances were analyzed based on fermentation rate parameters and yeast cell physiology. The kinetic fermentation parameters were studied by fitting the experimental data with four different kinetic models, Monod, Contois, modified Monod and Teisser. Encapsulated immobilized yeast fermentation was the closer one to the free cell fermentation. Due to the high diffusion inside the biocatalyst particles, inhibitory phenomena were avoided and the microbial activity was preserved. The vitality of the yeast cells, specific growth rate and the sugar uptake rate were directly related to the medium conditions and permeability of the immobilized capsule. Microscopic surveys of immobilized yeast cells, shows notable differences in cell growth performance of gelatin immobilization technique compared to free and two other immobilization techniques. Budding, pseudomycelium formation, vitality and contamination was better in entrapment and encapsulated immobilized yeast, compared to free cell suspension. http://dx.doi.org/10.1016/j.jbiotec.2017.06.982 Evaluation of hydrodynamic parameters and rheological behaviours for Haematococcus pluvialis production in stirred tank photobioreactor Bahar Aslanbay ∗ , Irem Deniz, Zeliha Demirel, Suphi Oncel, Esra Imamoglu Department of Bioengineering, Ege University, I˙ zmir, Turkey E-mail address: [email protected] (B. Aslanbay). Microalgae cultivation requires some specific conditions including temperature, light intensity, mixing, etc. They can be grown in an open system or in different type of closed photobioreactors depend on these conditions. Stirred tank photobioreactor is one of these systems and has common applications. The aim of this study was to cultivate a green microalga, Haematococcus pluvialis, in a stirred tank photobioreactor and to evaluate different hydrodynamic parameters. Firstly, microalgae were cultivated in BG11 culture medium with the mixing rate of 120 rpm in a 2 L stirred tank photobioreactor. Then, hydrodynamic parameters and rheological behaviors of culture medium were evaluated. The density and kinematic viscosity of the culture medium were 1018 kg/m3 and 5.89 × 10−6 m2 /s, respectively. The flow was in the turbulence region where the impeller Reynolds number was 9108.88 corresponding to the impeller tip speed of 1.99 m/s. Also, the specific growth rate of 0.22 day−1 was obtained at the end of the study. It was estimated that the reason of these slow cell growth was shear stress due to the mechanically stirring. The experiments on the evaluation of hydrodynamic parameters in stirred tank photobioreactor have given valuable information for the cultivation of H. pluvialis microalga and photobioreactor systems. http://dx.doi.org/10.1016/j.jbiotec.2017.06.983