Use ofK L a as a criterion for scaling up the inulinase fermentation process

Applied Biochemistry and Biotechnology - The scale-up of inulinase production in aerated cultures ofCandida kefyr DSM 70106 was studied, taking into account the criterion of maintainingK L a...     

On differential equations characterized by their Lie point symmetries

We study the geometry of differential equations determined uniquely by their point symmetries, that we call Lie remarkable. We determine necessary and sufficient conditions for a differential equation to be Lie remarkable. Furthermore, we see how, in some cases, Lie remarkability is related to the existence of invariant solutions. We apply our results to minimal submanifold equations and to Monge-Ampère equations in two independent variables of various orders.     

A question about basic algebras

We answer in the affirmative a question raised in a recent paper by Chajda, Halaš and Kühr, about characterizing lattice effect algebras among basic algebras.     

Systems of conservation laws with third-order Hamiltonian structures

We investigate n-component systems of conservation laws that possess third-order Hamiltonian structures of differential-geometric type. The classification of such systems is reduced to the projective classification of linear congruences of lines in \(\mathbb {P}^{n+2}\) satisfying additional geometric constraints. Algebraically, the problem can be reformulated as follows: for a vector space W of dimension \(n+2\), classify n-tuples of skew-symmetric 2-forms \(A^{\alpha } \in \varLambda ^2(W)\) such that

$$\begin{aligned} \phi _{\beta \gamma }A^{\beta }\wedge A^{\gamma }=0, \end{aligned}$$

for some non-degenerate symmetric \(\phi \).

     

Quantum Structures in Einstein General Relativity

We introduce the notion of a quantum structure on an Einstein general relativistic classical spacetime M. It consists of a line bundle over M equipped with a connection fulfilling certain conditions. We give a necessary and sufficient condition for the existence of quantum structures and classify them. The existence and classification results are analogous to those of geometric quantisation (Kostant and Souriau), but they involve the topology of spacetime, rather than the topology of the configuration space. We provide physically relevant examples, such as the Dirac monopole, the Aharonov–Bohm effect and the Kerr–Newman spacetime. Our formulation is carried out by analogy with the geometric approach to quantum mechanics on a spacetime with absolute time, given by Jadczyk and Modugno.     

Effect of k L a on the production of glucose 6-phosphate dehydrogenase from Saccharomyces cerevisiae grown by fermentation process

Applied Biochemistry and Biotechnology - In a 5-L fermentor (NBS-MF 105), Saccharomyces cerevisiae (0.7 g/L) was inoculated into a liquid medium (pH 4.0) containing 17 g/L of glucose, 2.55 g/L of...     

Partition behavior and partial purification of hexokinase in aqueous two-phase polyethylene glycol/citrate systems

This study dealt with the partition behavior and partial purification of hexokinase (HK) from baker’s yeast by liquid-liquid extraction using aqueous two-phase polyethylene glycol (PEG)/citrate systems. First, we investigated the effect of agitation type (vortex and 8 rpm rotation) on the stability of the system, and then the effects of sodium citrate concentration, PEG concentration, and molar mass of PEG on the partition coefficient of this enzyme by using a 2⁵ factorial experimental design. The results of this factorial experiment showed the possibility of a partial purification of HK by using two extraction steps, since the enzyme preferentially migrated to the top phase and the total proteins (mainly contaminants) remained in the bottom phase. The purification factor (Pur _TOP) of the enzyme in the top phase was 1.87, and the partition coefficient of the total proteins (K _Prot ) was 0.47.     

Stability estimates in time-backwards problem for the rod equation

In this paper we consider the equationu _tt +u _xxxx =0 for a vibrating rod supported at its end-points. We study the problem of determining the shape of the rod,u(·,0), knowingu(·,T). We see that the solution is unique ifT belongs to a certain dense subsetS of (0,+∞). IfT belongs toS, u(·,0) does not depend continuously onu(·,T). In this case, with the assumption of a bounded initial energy of the rod, we get stability estimates foru(·,0).     

Blocks and compatibility in $${{\rm d}_0}$$-algebras

The structure of \({{\rm d}_0}\)-algebra is a generalization of a D-lattice. We extend to this structure the definitions of compatible elements and blocks, and investigate their properties.     

Oxidation of glucose to gluconic acid by glucose oxidase in a membrane bioreactor

Glucose oxidase (GO) (EC 1.1.3.4) was used as catalyst for oxidizing glucose into gluconic acid utilizing a 10-mL Bioengineering Enzyme Membrane Reactor® or a 400-mL Millipore Stirred Ultrafiltration Cell (MSUC) coupled with a Millipore UF membrane (cutoff of 100 kDa) and operated for 12 h under an agitation of 100 rpm, pH 5.5, and 30°C. The effect of feeding rate (0.10, 0.15, or 0.20 min^?1), glucose (2.5 or 5.0 mM), and GO (1.0 or 2.0 mg/mL) concentrations on the catalysis were studied. A yield of about 75% was attained when the MSUC filled with 1.0 mg/mL of GO was fed with 2.5 mM glucose solution at a rate of 0.15 min^?1.