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The coding sequence of a peroxidase from the secretome of Pleurotus sapidus was cloned from a cDNA library. Bioinformatic analyses revealed an open reading frame of 1551 bp corresponding to a primary translation product of 516 amino acids. The DyP-type peroxidase was heterologously produced in Trichoderma reesei with an activity of 55,000 U L−1. The enzyme was purified from the culture supernatant, biochemically characterized and the kinetic parameters were determined. The enzyme has an N-terminal signal peptide composed of 62 amino acids. Analysis by Blue Native PAGE and activity staining with ABTS, as well as gel filtration chromatography showed the native dimeric state of the enzyme (115 kDa). Analysis of the substrate range revealed that the recombinant enzyme catalyzes, in addition to the conversion of some classic peroxidase substrates such as 2,2′-azino-bis(3-ethylthiazoline-6-sulfonate) and substituted phenols like 2,6–dimethoxyphenol, also the decolorization of the anthraquinonic dye Reactive Blue 5. The enzyme also catalyzes bleaching of natural colorants such as β-carotene and annatto. Surprisingly, β-carotene was transformed in the presence and absence of H2O2 by rPsaDyP, however enzyme activity was increased by the addition of H2O2. This indicates that the rPsaDyP has an oxidase function in addition to a peroxidase activity. As a consequence of the high affinity to the characteristic substrate Reactive Blue 5 the rPsaDyP belongs functionally to the dyp-type peroxidase family.

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Material distribution topology optimization methods aim to place optimally material within a given domain or space. These methos use a socalled material indicator function ρ to determine for each point within the design domain whether it contains material (ρ " 1) or void (ρ " 0). Eventually, I also thank to my friends and many people have been a part of my study in Sweden and I greatly appreciate to all of them. Quoc Khanh Nguyen Contents 1 Introduction 2 The finite elements methods for the linear elastostatics 2.1 Variational form 2.2 Existence and Uniqueness of the Solution 2.3 Finite Element Approximation 3 Topology optimization by isotropic material distribution 3.1 The minimization of the compliance for the cantilever beam 3.2 Numerical solution and implementation 3.2.1 Discretization 3.3 Condition of optimality 4 Nonlinear filters in topology optimization 4.1 Conditions of filters and their implications 4.2 The class of fW-mean filters 4.3 Octagonal neighbourhood 4.4 Sensitivity evaluation 4.5 Cascaded fW-mean filters 5 Preconditioning of the linear system 6 Numerical experiments and results 7 Conclusions References List of Figures 1 Demonstration of linear elastrostatics problem of body Ω deforming under a internal force b and boundary force t. The solid line illustrates the initial state and the dashed line shows the deformed state of configuration [1]. 2 Geometry for the cantilever beam problem. 3 The physical density after relaxing as ρpxq P r0, 1s. 4 The physical density with mesh-dependency problem. The left figure is solution for 96ˆ64 elements discretization and the right figure is solution for 384ˆ256 elements discretization. 5 The physical density after using mean filter. 6 Octagonal shaped neighbourhood with filter radius r " 10 elements and parameter q " 4 elements. 7 One-dimension geometry of the minimization of compliance for a bar. 8 The surface plot for the variation of condition number of stiffness matrix with preconditioning as the function of r ρ 2 and r ρ 3. 9 Geometry of the minimization of compliance for a 1D bar when r ρ 2 " , r ρ 3 " 1 and Ñ 0. 10 Geometry of the minimization of compliance for a 1D bar when r ρ 2 " r ρ 3 " , Ñ 0. 11 Cantilever beams optimized using 384ˆ256 (top) and 768ˆ512 (bottom) elements and different harmonic open-close filter. The octagonal neighbourhoods are indicated in the upper-right corner of each sub-figure. The relative ratio between the filter radius used in the open and close step is 1. 12 Cantilever beam optimized using 768ˆ512 elements and different harmonic open-close filter. The octagonal neighbourhoods are indicated in the upper-right corner of each sub-figure. The relative ratio between the filter radius used in the open and close step of two top and bottom sub-figures and is 4 and 1/4 respectively. 13 The variation of condition number of stiffness matrix with and without preconditioning during topology optimization iterations.

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