Development of a recombinant brewing yeast to produce beer from hemp extract (\u3cem\u3eCannabis Sativa L.\u3c/em\u3e)

The Cannabis industry is a rapidly-growing market in Canada. With the legalization of edible products in 2019, many cannabis-derived candies, baked goods, beverages appeared on shelves. Cannabis beer can be brewed by replacing barley with pretreated cannabis plant. However, using a traditional brewing yeast to brew cannabis beer will result in incomplete fermentation which will affect the beer’s composition and flavour because traditional brewing yeasts are not able to utilize xylose which is an abundant carbohydrate in lignocellulosic extracts. Using a recombinant strain of a brewing yeast and a xylose-fermenting yeast can overcome this issue. The work presented in this thesis compares the fermentation performance of two native xylose-fermenting yeast strains, Pichia stipitis and Spathaspora passalidarum, and performs the transformation with a brewing yeast via electroporation. Fermentation performance of the xylose-fermenting yeasts were evaluated in mixed carbohydrate medium, containing cellobiose, glucose and xylose. Under aerobic conditions, carbohydrate consumption rates of both strains were faster than the rates under anaerobic conditions, but aerobic conditions led to ethanol respiration by P. stipitis and S. passalidarum. Under anaerobic conditions and at high glucose concentrations, S. passalidarum sequentially utilized glucose and xylose, while glucose decreased xylose utilization ability of P. stipitis. S. passalidarum also exhibited higher ethanol tolerance compared to P. stipitis. Transformation of brewing yeast strains and S. passalidarum were conducted using electroporation-based transformation. Genomic DNA of the donor strain, S. passalidarum, was extracted using phenol-chloroform extraction and transferred into host strains, an ale and a lager strain, using an electric pulse. Putative recombinants were selected on plates containing xylose as the sole carbon source, however, obtained recombinants strains were deemed to be unstable due to the aneuploid nature of the host strains

Simulations of the infrared, Raman, and 2D-IR photon echo spectra of water in nanoscale silica pores

Vibrational spectroscopy is frequently used to characterize nanoconfined liquids and probe the effect of the confining framework on the liquid structure and dynamics relative to the corresponding bulk fluid. However, it is still unclear what molecular-level information can be obtained from such measurements. In this paper, we address this question by using molecular dynamics (MD) simulations to reproduce the linear infrared (IR), Raman, and two-dimensional IR (2D-IR) photon echo spectra for water confined within hydrophilic (hydroxyl-terminated) silica mesopores. To simplify the spectra the OH stretching region of isotopically dilute HOD in D2O is considered. An empirical mapping approach is used to obtain the OH vibrational frequencies, transition dipoles, and transition polarizabilities from the MD simulations. The simulated linear IR and Raman spectra are in good general agreement with measured spectra of water in mesoporous silica reported in the literature. The key effect of confinement on the water spectrum is a vibrational blueshift for OH groups that are closest to the pore interface. The blueshift can be attributed to the weaker hydrogen bonds (H-bonds) formed between the OH groups and silica oxygen acceptors. Non-Condon effects greatly diminish the contribution of these OH moieties to the linear IR spectrum, but these weaker H-bonds are readily apparent in the Raman spectrum. The 2D-IR spectra have not yet been measured and thus the present results represent a prediction. The simulated spectra indicates that it should be possible to probe the slower spectral diffusion of confined water compared to the bulk liquid by analysis of the 2D-IR spectra

Origins of the non-exponential reorientation dynamics of nanoconfined water

This is the published version. Copyright 2014 American Institute of PhysicsThe dynamics of water are dramatically modified upon confinement in nanoscale hydrophilic silica pores. In particular, the OH reorientation dynamics of the interfacial water are non-exponential and dramatically slowed relative to the bulk liquid. A detailed analysis of molecular dynamics simulations is carried out to elucidate the microscopic origins of this behavior. The results are analyzed in the context of the extended jump model for water that describes the reorientation as a combination of hydrogen-bond exchanges, or jumps, and rotation of intact hydrogen bonds, with the former representing the dominant contribution. Within this model, the roles of surface and dynamical heterogeneities are considered by spatially resolving the hydrogen-bond jump dynamics into individual sites on the silica pore surface. For each site the dynamics is nearly mono-exponential, indicating that dynamical heterogeneity is at most a minor influence, while the distribution of these individual site jump times is broad. The non-exponential dynamics can also not be attributed to enthalpic contributions to the barriers to hydrogen-bond exchanges. Two entropic effects related to the surface roughness are found to explain the retarded and diverse dynamics: those associated with the approach of a new hydrogen-bond acceptor and with the breaking of the initial hydrogen-bond

Aqueous electrolytes confined within functionalized silica nanopores

Molecular dynamics simulations have been carried out to investigate structural and dynamical characteristics of NaCl aqueous solutions confined within silica nanopores in contact with a “bulk-like” reservoir. Two types of pores, with diameters intermediate between 20 Å and 37.5 Å, were investigated: The first one corresponded to hydrophobic cavities, in which the prevailing wall-solution interactions were of the Lennard-Jones type. In addition, we also examined the behavior of solutions trapped within hydrophilic cavities, in which a set of unsaturated O-sites at the wall were transformed in polar silanol Si–OH groups. In all cases, the overall concentrations of the trapped electrolytes exhibited important reductions that, in the case of the narrowest pores, attained 50% of the bulk value. Local concentrations within the pores also showed important fluctuations. In hydrophobic cavities, the close vicinity of the pore wall was coated exclusively by the solvent, whereas in hydrophilic pores, selective adsorption of Na+ ions was also observed. Mass and charge transport were also investigated. Individual diffusion coefficients did not present large codifications from what is perceived in the bulk; contrasting, the electrical conductivity exhibited important reductions. The qualitative differences are rationalized in terms of simple geometrical considerations.Peer ReviewedPostprint (published version

Forensic Medicine and Sciences in Turkey

This chapter provides readers with a better understanding of Turkish Forensic Sciences and the Turkish Legal Medicine and Judicial System as well as its expertise and development. We discuss the historical aspect of the forensic sciences in the country and the developmental process with all the criticism on the subjects. We try to evaluate the international relations of the state and the changing attitudes towards the medicolegal system. The state is working very intensively on the quality assurance and standardization issues in forensic sciences. The effects of relations between the European Union are discussed and serious changes to be made in Criminal and Civil Laws and also Criminal and Civil Code Laws with reflections on forensic expertise. The chapter summarizes the new developments and the future of forensic sciences in the country in accordance with the State Supervisory Board report. © 2015 John Wiley & Sons Ltd

KR Cygni: A near-contact eclipsing binary?

WOS: 000224437000004In this study we present photometric observations of the eclipsing binary KR Cyg made in 1999 and 2000. The observations of the eclipsing binary KR Cyg have been carried out in B, V and R colours at the Ege University Observatory. A new seasonal light curves are presented. New times of minima and ephemerides are given. Based on a statistical analysis of the times of minima obtained by photoelectric photometry, the orbital period of the system is found to be constant. The photometric mass ratio of the system is well determined. The corresponding light curves were analyzed by the Wilson-Devinney code