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VOCs biodegradation in multiphase systems
New Biotechnology · Volume 25S · September 2009
ABSTRACTS
2.4.40
2.4.42
Relationship between the properties of nonionic surfactants and their effects on asymmetric reduction of 2-octanone with Saccharomyces cerevisiae
VOCs biodegradation in multiphase systems
X.A. Shi ∗ , Y.H. Guo College of Biological Science and Technology, Fuzhou University, Fuzhou, China
Experiments showed some nonionic surfactants added to aqueous buffer system could improve the asymmetric reduction of 2-octanone with Saccharomyces cerevisiae. Moreover, it was manifested that a shorter of carbon chain length of hydrophilic moiety or hydrophobic moiety in surfactants would result in a higher yield of (S)-2-octanol. With respect to the product e.e., the alkylphenol ethoxylate surfactants had a much less influence than polyoxyethylenesorbitan trialiphatic surfactants, which showed that the product e.e. resulted from the change of carbon chain length of the hydrophobic moiety would be varied markedly than that resulted from the change of carbon chain length of the hydrophilic moiety. Especially, among the surfactants assayed, Emulsifier OP10 and Tween 20 could markedly improve the yield and product e.e. at the concentration of 0.4 mmol L−1 with the yield of 73.3% and 93.2%, and the product e.e. of 99.2% and 99.3%, respectively, at a reaction time of 96 hours. doi:10.1016/j.nbt.2009.06.527
2.4.41 The solvent effect of ethanol and n-hexane on the hydrolysis of triolein and tributyrin by Candida cylindracea lipase A. Koc ¸ 1,∗ , D. Özer 2 , H.I. Ekiz 3 1 Department of Chemical Engineering, Faculty of Engineering, University of ˙Inönü, Malatya, Turkey 2 Department of Chemical Engineering, Faculty of Engineering, University of ˘ Turkey Fırat, Elazıg, 3 Department of Food Engineering, Faculty of Engineering, University of Mersin, Mersin, Turkey
In this study, triolein and tributyrin were used as substrates and ethanol and n-hexane were used as solvents in enzyme catalytic hydrolysis of triglycerides. The initial reaction rate of triolein hydrolysis, increased up to 0.00516 mol L−1 of triolein concentration then it decreased. The maximum initial reaction rate of triolein hydrolysis was found 17.850 and 9.425 without ethanol and presence ethanol media 2% (v/v), respectively. Thus ethanol was effected mixed type inhibitor of initial reaction rate on triolein hydrolysis. The hydrolysis reaction rate of tributyrin increased up to 0.0513 mol L−1 of tributyrin concentration then it decreased slightly. The maximum initial reaction rate of tributyrin hydrolysis found 180.52 and 103.09 without n-hexane and at presence n-hexane media 2% (v/v), respectively. Thus n-hexane effected uncompetitive inhibitor of initial reaction rate on tributyrin hydrolysis. doi:10.1016/j.nbt.2009.06.528
S166
www.elsevier.com/locate/nbt
A. Trusek-Holownia ∗ , A. Noworyta Wroclaw University of Technology, Department of Chemistry, Wroclaw, Poland
Emission and removal of VOCs is a subject of constant legislative and research interest. An appropriate approach to this topic is no longer the matter of a ‘factory-polluter’, but an international problem. Classic methods for removal of VOCs from outlet gases include first of all adsorption and absorption methods which are used to transfer an organic compound from the gas to solid phase or liquid phase, at its significant concentration. A problem is still its further treatment after the sorbent regeneration. When only one dominating component is released during desorption, it is most reasonable to use it again. In an opposite case, either catalytic burning or chemical or biological degradation can be applied. In carried experiments, the strains of Acinetobacter baumanii and Acinetobacter lwoffi isolated from polluted soil were used and a broad spectrum of VOCs as the only source of carbon and energy was tested. A. baumanii is able to degrade alcohols, benzene and higher alkanes (more than eight carbons) while A. lwoffi alcohols and alkanes: hexane and higher. As it was checked the biodegradation processes of analyzing compounds have ran at very low specific growth rate, thus they should be intensify on some way. A good solution is process running in a membrane bioreactor. Taking into account solubility of particular compounds (generally low in water), the following treatment by the biological method was proposed: Compounds very well soluble in water (e.g. alcohols) are transferred from gas to a solid carrier. The adsorbent is regenerated with overheated steam and as a result a concentrated solution of the component is obtained. In carried experiments the solution was supplied to the stirred flow membrane bioreactor at a different rate. A UF-membrane separated microbial cells was applied. Compounds with limited, like benzene, can be supplied to the bioreactor owing to direct extraction from the absorber phase (like HMN, silicone oil). This process was carried out in a membrane phase contactor supplied with polypropylene membrane. Strongly hydrophobic compounds, for example alkanes, after desorption from a solid carrier and after phase separation, were supplied as an oil phase to a multiphase bioreactor and the biodegradation process takes place first of all on the boundary of emulsified droplets. Unconverted oil phase simultaneous with microbial cells were separated by the applied UF-ceramic membrane. Even at very low VOCs water-solubility it is possible to carry out their effective biodegradation when a membrane bioreactor is applied. doi:10.1016/j.nbt.2009.06.529
ABSTRACTS
2.4.40
2.4.42
Relationship between the properties of nonionic surfactants and their effects on asymmetric reduction of 2-octanone with Saccharomyces cerevisiae
VOCs biodegradation in multiphase systems
X.A. Shi ∗ , Y.H. Guo College of Biological Science and Technology, Fuzhou University, Fuzhou, China
Experiments showed some nonionic surfactants added to aqueous buffer system could improve the asymmetric reduction of 2-octanone with Saccharomyces cerevisiae. Moreover, it was manifested that a shorter of carbon chain length of hydrophilic moiety or hydrophobic moiety in surfactants would result in a higher yield of (S)-2-octanol. With respect to the product e.e., the alkylphenol ethoxylate surfactants had a much less influence than polyoxyethylenesorbitan trialiphatic surfactants, which showed that the product e.e. resulted from the change of carbon chain length of the hydrophobic moiety would be varied markedly than that resulted from the change of carbon chain length of the hydrophilic moiety. Especially, among the surfactants assayed, Emulsifier OP10 and Tween 20 could markedly improve the yield and product e.e. at the concentration of 0.4 mmol L−1 with the yield of 73.3% and 93.2%, and the product e.e. of 99.2% and 99.3%, respectively, at a reaction time of 96 hours. doi:10.1016/j.nbt.2009.06.527
2.4.41 The solvent effect of ethanol and n-hexane on the hydrolysis of triolein and tributyrin by Candida cylindracea lipase A. Koc ¸ 1,∗ , D. Özer 2 , H.I. Ekiz 3 1 Department of Chemical Engineering, Faculty of Engineering, University of ˙Inönü, Malatya, Turkey 2 Department of Chemical Engineering, Faculty of Engineering, University of ˘ Turkey Fırat, Elazıg, 3 Department of Food Engineering, Faculty of Engineering, University of Mersin, Mersin, Turkey
In this study, triolein and tributyrin were used as substrates and ethanol and n-hexane were used as solvents in enzyme catalytic hydrolysis of triglycerides. The initial reaction rate of triolein hydrolysis, increased up to 0.00516 mol L−1 of triolein concentration then it decreased. The maximum initial reaction rate of triolein hydrolysis was found 17.850 and 9.425 without ethanol and presence ethanol media 2% (v/v), respectively. Thus ethanol was effected mixed type inhibitor of initial reaction rate on triolein hydrolysis. The hydrolysis reaction rate of tributyrin increased up to 0.0513 mol L−1 of tributyrin concentration then it decreased slightly. The maximum initial reaction rate of tributyrin hydrolysis found 180.52 and 103.09 without n-hexane and at presence n-hexane media 2% (v/v), respectively. Thus n-hexane effected uncompetitive inhibitor of initial reaction rate on tributyrin hydrolysis. doi:10.1016/j.nbt.2009.06.528
S166
www.elsevier.com/locate/nbt
A. Trusek-Holownia ∗ , A. Noworyta Wroclaw University of Technology, Department of Chemistry, Wroclaw, Poland
Emission and removal of VOCs is a subject of constant legislative and research interest. An appropriate approach to this topic is no longer the matter of a ‘factory-polluter’, but an international problem. Classic methods for removal of VOCs from outlet gases include first of all adsorption and absorption methods which are used to transfer an organic compound from the gas to solid phase or liquid phase, at its significant concentration. A problem is still its further treatment after the sorbent regeneration. When only one dominating component is released during desorption, it is most reasonable to use it again. In an opposite case, either catalytic burning or chemical or biological degradation can be applied. In carried experiments, the strains of Acinetobacter baumanii and Acinetobacter lwoffi isolated from polluted soil were used and a broad spectrum of VOCs as the only source of carbon and energy was tested. A. baumanii is able to degrade alcohols, benzene and higher alkanes (more than eight carbons) while A. lwoffi alcohols and alkanes: hexane and higher. As it was checked the biodegradation processes of analyzing compounds have ran at very low specific growth rate, thus they should be intensify on some way. A good solution is process running in a membrane bioreactor. Taking into account solubility of particular compounds (generally low in water), the following treatment by the biological method was proposed: Compounds very well soluble in water (e.g. alcohols) are transferred from gas to a solid carrier. The adsorbent is regenerated with overheated steam and as a result a concentrated solution of the component is obtained. In carried experiments the solution was supplied to the stirred flow membrane bioreactor at a different rate. A UF-membrane separated microbial cells was applied. Compounds with limited, like benzene, can be supplied to the bioreactor owing to direct extraction from the absorber phase (like HMN, silicone oil). This process was carried out in a membrane phase contactor supplied with polypropylene membrane. Strongly hydrophobic compounds, for example alkanes, after desorption from a solid carrier and after phase separation, were supplied as an oil phase to a multiphase bioreactor and the biodegradation process takes place first of all on the boundary of emulsified droplets. Unconverted oil phase simultaneous with microbial cells were separated by the applied UF-ceramic membrane. Even at very low VOCs water-solubility it is possible to carry out their effective biodegradation when a membrane bioreactor is applied. doi:10.1016/j.nbt.2009.06.529