http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Effect of pH on Successive Foam and Sonic Droplet Fractionation of a Bromelain-invertase Mixture
Robert D. Tanner,Samuel Ko,Ales Prokop 한국생물공학회 2002 Biotechnology and Bioprocess Engineering Vol.7 No.1
A droplet fractionation method was previously developed to concentrate a dilute non-foaming protein solution. In that earlier study with invertase, it was demonstrated that droplets created by ultrasonic energy waves could be enriched up to 8 times that of the initial dilute invertase solution. In this study, a mixture of bromelain (a foaming protein) and invertase (a non-foaming protein) is investigated as a preliminary step to determine if droplet fractionation can also be used to separate a non-foaming protein from foaming proteins. The foaming mixture containing bromelain is first removed by bubbling the binary mixture with air. After the foam is removed, the protein rich air-water interfacial layer is skimmed off (prior to droplet fractionation) so as not to interfere with the subsequent droplet production from the remaining bulk liquid, rich in non-foaming protein. Finally, sonic energy waves are then applied to this residual bulk liquid to recover droplets containing the non-foaming protein, presumed to be invertase. The primary control variable used in this droplet fractionation process is the pH, which ranged for separate experiments between 2 and 9. It was observed that the maximum overall protein partition coefficients of 5 and 4 were achieved at pH 2 and 4, respectively, for the initial foaming experiment followed by the post foaming droplet fractionation experiment.
Effect of pH on Successive Foam and Sonic Droplet Fractionation of a Bromelain-invertase Mixture
Ko Samuel,Prokop Ales,Tanner Robert D. The Korean Society for Biotechnology and Bioengine 2002 Biotechnology and Bioprocess Engineering Vol.7 No.1
A droplet fractionation method was previously developed to concentrate a dilute nonfoaming protein solution. In that earlier study with invertase, it was demonstrated that droplets created by ultrasonic energy waves could be enriched up to 8 times that of the initial dilute invertase solution. In this study, a mixture of bromelain (a foaming protein) and invertase (a nonfoaming protein) is investigated as a preliminary step to determine if droplet fractionation can also be used to separate a non-foaming protein from foaming proteins. The foaming mixture containing bromelain is first removed by bubbling the binary mixture with air. After the foam is removed, the protein rich air-water interfacial layer is skimmed off (prior to droplet fractionation) so as not to interfere with the subsequent droplet production from the remaining bulk liquid, rich in non-foaming protein. Finally, sonic energy waves are then applied to this residual bulk liquid to recover droplets containing the non-foaming protein, presumed to be invertase. The primary control variable used in this droplet fractionation process is the pH, which ranged for separate experiments between 2 and 9. It was observed that the maximum overall protein partition coefficients of 5 and 4 were achieved at pH 2 and 4, respectively, for the initial foaming experiment followed by the post foaming droplet fractionation experiment.
Association of brain heptachlor epoxide and other organochlorine compounds with lewy pathology
Ross, G. Webster,Abbott, Robert D.,Petrovitch, Helen,Duda, John E.,Tanner, Caroline M.,Zarow, Chris,Uyehara‐,Lock, Jane H.,Masaki, Kamal H.,Launer, Lenore J.,Studabaker, William B.,White, Lon R. John Wiley Sons, Inc. 2019 Movement disorders Vol.34 No.2
<P><B>ABSTRACT</B></P><P><B>Background</B></P><P>Organochlorine pesticides are associated with an increased risk of Parkinson's disease. A preliminary analysis from the Honolulu‐Asia Aging Study suggested that heptachlor epoxide, a metabolite from an organochlorine pesticide extensively used in Hawaii, may be especially important. This was a cross sectional analysis to evaluate the association of heptachlor epoxide and other organochlorine compounds with Lewy pathology in an expanded survey of brain organochlorine residues from the longitudinal Honolulu‐Asia Aging Study.</P><P><B>Methods</B></P><P>Organochlorines were measured in frozen occipital or temporal lobes in 705 brains using gas chromatography with mass spectrometry. Lewy pathology was identified using hematoxylin and eosin‐ and α‐synuclein immunochemistry‐stained sections from multiple brain regions.</P><P><B>Results</B></P><P>The prevalence of Lewy pathology was nearly doubled in the presence versus the absence of heptachlor epoxide (30.1% versus 16.3%, <I>P</I> < 0.001). Although associations with other compounds were weaker, hexachlorobenzene (<I>P</I> = 0.003) and α‐chlordane (<I>P</I> = 0.007) were also related to Lewy pathology. Most of the latter associations, however, were a result of confounding from heptachlor epoxide. Neither compound was significantly related to Lewy pathology after adjustment for heptachlor epoxide. In contrast, the association of heptachlor epoxide with Lewy pathology remained significant after adjustments for hexachlorobenzene (<I>P</I> = 0.013) or α‐chlordane (<I>P</I> = 0.005). Findings were unchanged after removal of cases of PD and adjustment for age and other characteristics.</P><P><B>Conclusions</B></P><P>Organochlorine pesticides are associated with the presence of Lewy pathology in the brain, even after exclusion of PD cases. Although most of the association is through heptachlor epoxide, the role of other organochlorine compounds is in need of clarification. © 2018 International Parkinson and Movement Disorder Society</P>
Light Mediated Yeast Cell Growth and Metabolism
Dowd Jr, Christopher J.,Tanner, Robert D. The Korean Society for Biotechnology and Bioengine 1991 KSBB Journal Vol.6 No.3
In this paper the effect of light on non-aerated Baker's Yeast(Saccharomyces cereuisiae) production and the protein excretion to the extracellular fluid is studied. Previous results in our laboratory indicate that at pH=5 and T-32$^{\circ}C$ yeast may be affected by light, but those differences seem to be within statistical variation of the data. In this paper, cell and extracellular protein concentrations along with redox potential are monitored for batch fermentations in the presence and absence of light at pH levels of 3 and 5 and at 31$^{\circ}C$, in order to explore whether possible light effects can be more readily discerned at lower pH values. Yeast particle size distributions are also determined over the course of fermentation using a particle counter in order to add one more measuring tool to our usual cell and total protein measurements. An apparently noticeable difference in the redox potential is observed between the light and the dark runs for early times for the pH=3 runs. The particle size distributions show differences in the particle diameters between light and dark runs at pH=3, but those differences fall within one standard deviation of the mean particle diameters.
Modeling the Catalytic Activity and Kinetics of Lipase(Glycerol-Ester Hydrolase)
Demirer, Goksel N.,Duran, Metin,Tanner, Robert D. The Korean Society for Biotechnology and Bioengine 1996 Biotechnology and Bioprocess Engineering Vol.1 No.1
In order to design industrial scale reactors and proceises for multi-phase biocatalytic reactions, it is essential to understand the mechanisms by which such systems operate. To il-lustrate how such mechanisms can be modeled, the hydrolysis of the primary ester groups of triglycerides to produce fatty acids and monoglycerides by lipased (glycerol-ester hydrolase) catalysis has been selected as an example of multiphase biocatalysis. Lipase is specific in its behavior such that it can act only on the hydrolyzed (or emulsified) part of the substrate. This follows because the active center of the enzyme is catalytically active only when the substrate contacts it in its hydrolyzed form. In other words, lipase acts only when it can shuttleback and forth between the emulsion phase and the water phase, presumably within an interphase or boundary layer between these two phases. In industrial applications lipase is employed as a fat splitting enzyme to remove fat stains from fabrics, in making cheese, to flavor milk products, and to degrade fats in waste products. Effective use of lipase in these processes requires a fundamental understanding of its kinetic behavior and interactions with substrates under various environmental conditions. Therefore, this study focuses on modeling and simulating the enzymatic activity of the lipase as a step towards the basic understanding of multi-phase biocatalysis processes.