Engineering of Klebsiella oxytoca capable of simultaneous utilization of multiple sugars for the production of 2, 3- Butanediol

From various biomasses such as lignocellulose and microalgae, many kinds of monosaccharides including glucose, galactose, xylose, mannose, ribose, rhamnose, and fucose can be obtained. Among them, galactose and xylose are the major carbon sources except for glucose in nature, and both sugars can serve as additive for the production of desired chemicals in the glucose-based fermentation. However, in many microorganisms, the glucose hampers utilization of galactose and xylose until depletion of glucose owing to Carbon Catabolite Repression (CCR) mechanism, which has been a big hurdle for the development of bioprocess utilizing multiple carbon sugars. Here, we developed Klebsiella oxytoca capable of simultaneous utilization of three sugars including glucose, galactose and xylose for the fermentative production of 2,3-butanediol which is a vital platform compound, used as liquid fuel and chemical raw material. To eliminate CCR and utilize multiple sugars, the phosphotransferase system (PTS) which is the main transporter for glucose was disrupted, in which cells could uptake glucose through alternative pathway and the transport system for other sugars could be activated. To verify the removal of CCR by disruption of PTS, the engineered strain was cultivated with two or three sugars and, we found that the simultaneous consumption of galactose and xylose was achieved although glucose consumption rate was decreased a little. At the time point of complete consumption of glucose, most galactose was also consumed and, about 30 % of xylose was consumed before glucose depletion. Under the simultaneous utilization of galactose and xylose along with glucose, 2,3-butaneidol was also successfully produced as high as 0.3 g/g, which yield is similar as that in cultivation with glucose as a sole carbon source. To the best of our knowledge, this is the first example of CCR elimination in K. oxytoca and, we think that our strategy sheds new light on an engineering of K. oxytoca for commercial exploitation of biomass to produce value-added products

PREFACE

PREFAC

More on complexity of operators in quantum field theory

Recently it has been shown that the complexity of SU($n$) operator is determined by the geodesic length in a bi-invariant Finsler geometry, which is constrained by some symmetries of quantum field theory. It is based on three axioms and one assumption regarding the complexity in continuous systems. By relaxing one axiom and an assumption, we find that the complexity formula is naturally generalized to the Schatten $p$-norm type. We also clarify the relation between our complexity and other works. First, we show that our results in a bi-invariant geometry are consistent with the ones in a right-invariant geometry such as $k$-local geometry. Here, a careful analysis of the sectional curvature is crucial. Second, we show that our complexity can concretely realize the conjectured pattern of the time-evolution of the complexity: the linear growth up to saturation time. The saturation time can be estimated by the relation between the topology and curvature of SU($n$) groups.Comment: Modified the Sec. 4.1, where we offered a powerful proof: if (1) the ket vector and bra vector in quantum mechanics contain same physics, or (2) adding divergent terms to a Lagrangian will not change underlying physics, then complexity in quantum mechanics must be bi-invariant

CONFERENCE PROGRAM

Fluidization XIII: New Paradigm in Fluidization Engineering May 16-21, 2010 Hotel Hyundai, Gyeong-ju, Kore

Principles and symmetries of complexity in quantum field theory

Based on general and minimal properties of the {\it discrete} circuit complexity, we define the complexity in {\it continuous} systems in a geometrical way. We first show that the Finsler metric naturally emerges in the geometry of the complexity in continuous systems. Due to fundamental symmetries of quantum field theories, the Finsler metric is more constrained and consequently, the complexity of SU($n$) operators is uniquely determined as a length of a geodesic in the Finsler geometry. Our Finsler metric is bi-invariant contrary to the right-invariance of discrete qubit systems. We clarify why the bi-invariance is relevant in quantum field theoretic systems. After comparing our results with discrete qubit systems we show most results in $k$-local right-invariant metric can also appear in our framework. Based on the bi-invariance of our formalism, we propose a new interpretation for the Schr\"{o}dinger's equation in isolated systems - the quantum state evolves by the process of minimizing "computational cost."Comment: Published version; added a short introduction on Finsler geometr

Influence of HEMA content on the mechanical and bonding properties of experimental HEMA-added glass ionomer cements

The purpose of this study was to determine the influence of incrementally added uncured HEMA in experimental HEMA-added glass ionomer cement (HAGICs) on the mechanical and shear bond strength (SBS) of these materials. Increasing contents of uncured HEMA (10-50 wt.%) were added to a commercial glass ionomer cement liquid (Fuji II, GC, Japan), and the compressive and diametral tensile strengths of the resulting HAGICs were measured. The SBS to non-precious alloy, precious alloy, enamel and dentin was also determined after these surfaces were subjected to either airborne-particle abrasion (Aa) or SiC abrasive paper grinding (Sp). Both strength properties of the HAGICs first increased and then decreased as the HEMA content increased, with a maximum value obtained when the HEMA content was 20% for the compressive strength and 40% for the tensile strength. The SBS was influenced by the HEMA content, the surface treatment, and the type of bonding surface (