Solid-state fermentation of lignocellulosic plant residues from Brassica napus by Pleurotus ostreatus

Solid-state fermentation (SSF) of inedible parts of rapeseed was carried out using a white-rot fungus, Pleurotus ostreatus, to degrade lignocellulosic material for mycelial-single cell protein (SCP) production. This SSF system has the potential to be adapted to a controlled ecological life support system in space travel owing to the lack of storage space. The system for converting lignocellulosic material to SCP by P. ostreatus is simple; it can be carried out in a compact reactor. The fungal vegetative growth was better with a particle size of plant material ranging from 0.42 to 10 mm, whereas lignin degradation of the lignocellulose was the highest with particle sizes ranging from 0.42 to 0.84 mm. The addition of veratry alcohol (3,4-dimethoxybenzyl alcohol), hydrogen peroxide, and glycerol promotes lignocellulose degradation by P. ostreatus. The enhancement of bioconversion was also observed when a gas-flow bioreactor was used to supply oxygen and to maintain the constant moisture of the reactor. With this reactor, approx 85% of the material was converted to fungal and other types of biomass after 60 d of incubation.     

On the Bessel Heat Equation Related to the Bessel Diamond Operator

In this article, we study the equation

$\frac{\partial }{\partial t}u(x,t)=c^{2}\Diamond _{B}^{k}u(x,t)$

with the initial condition u(x,0)=f(x) for x∈? _n ⁺ . The operator ? _B ^k is named to be Bessel diamond operator iterated k-times and is defined by

$\Diamond _{B}^{k}=\bigl[(B_{x_{1}}+B_{x_{2}}+\cdots +B_{x_{p}})^{2}-(B_{x_{p+1}}+\cdots +B_{x_{p+q}})^{2}\bigr]^{k},$

where k is a positive integer, p+q=n, \(B_{x_{i}}=\frac{\partial ^{2}}{\partial x_{i}^{2}}+\frac{2v_{i}}{x_{i}}\frac{\partial }{\partial x_{i}},\) 2v _i =2α _i +1,\(\;\alpha _{i}>-\frac{1}{2}\), x _i >0, i=1,2,…,n, and n is the dimension of the ? _n ⁺ , u(x,t) is an unknown function of the form (x,t)=(x ₁,…,x _n ,t)∈? _n ⁺ ×(0,∞), f(x) is a given generalized function and c is a positive constant (see Levitan, Usp. Mat. 6(2(42)):102–143, 1951; Y?ld?r?m, Ph.D. Thesis, 1995; Y?ld?r?m and Sar?kaya, J. Inst. Math. Comput. Sci. 14(3):217–224, 2001; Y?ld?r?m, et al., Proc. Indian Acad. Sci. (Math. Sci.) 114(4):375–387, 2004; Sar?kaya, Ph.D. Thesis, 2007; Sar?kaya and Y?ld?r?m, Nonlinear Anal. 68:430–442, 2008, and Appl. Math. Comput. 189:910–917, 2007). We obtain the solution of such equation, which is related to the spectrum and the kernel, which is so called Bessel diamond heat kernel. Moreover, such Bessel diamond heat kernel has interesting properties and also related to the kernel of an extension of the heat equation.

     

Rigid biological composite materials: Structural examples for biomimetic design

Biological hard tissues are composites of inorganics and biopolymers, and, therefore, represent hybrid systems. The inorganic components may be oxides (e.g., SiO₂, Fe₃O₄), carbonates (e.g., CaCO₃) sulfides (e.g., FeS, CdS), or others, mostly in crystalline forms but also occasionally in glassy forms. The biopolymer is often proteinaceous, but can also involve lipids and especially polysaccharides (e.g., chitin). These hybrid materials can be found in single celled organisms (such as bacteria and protozoa), invertebrates (such as mollusks), insects (such as beetles), and vertebrates (such as mammals). A common denominator of all hard tissues is that they are hierarchically structured from the nanometer scale to the microscale and the macroscale. It is these controlled structures that give biological hard tissues their unique and highly evolved functional properties. The engineering properties include mechanical, piezoelectric, optical, and magnetic. The hard tissues can be in the form of nanoparticles, spines, spicules, skeletons, and shells. The objective of this paper is to demonstrate mechanical aspects of some of these hard tissues, to discuss their structure-function relationships (with examples from the literature as well as from our research), and to reveal their potential utility in materials science and engineering applications.     

Input Resistance Calculation for Circular Microstrip Antennas Using Adaptive Neuro-Fuzzy Inference System

This paper presents a new method based on adaptive neuro-fuzzy inference system (ANFIS) to calculate the input resistance of circular microstrip patch antennas. The ANFIS is a fuzzy inference system (FIS) implemented in the framework of an adaptive fuzzy neural network. It combines the explicit knowledge representation of FIS with learning power of neural networks. A hybrid learning algorithm based on the least square approach and the backpropagation algorithm is used to optimize the parameters of ANFIS. The input resistance results predicted by ANFIS are in excellent agreement with the experimental results reported elsewhere.     

Adsorption behavior of linear and cyclic genetically engineered platinum binding peptides

Recently, phage and cell-surface display libraries have been adapted for genetically selecting short peptides for a variety of inorganic materials. Despite the enormous number of inorganic-binding peptides reported and their bionanotechnological utility as synthesizers and molecular linkers, there is still a limited understanding of molecular mechanisms of peptide recognition of and binding to solid materials. As part of our goal of genetically designing these peptides, understanding the binding kinetics and thermodynamics, and using the peptides as molecular erectors, in this report we discuss molecular structural constraints imposed upon the quantitative binding characteristics of peptides with an affinity for inorganics. Specifically, we use a high-affinity seven amino acid Pt-binding sequence, PTSTGQA, as we reported in earlier studies and build two constructs: one is a Cys-Cys constrained "loop" sequence (CPTSTGQAC) that mimics the domain used in the pIII tail sequence of the phage library construction, and the second is the linear form, a septapeptide, without the loop. Both sequences were analyzed for their adsorption behavior on Pt thin films by surface plasmon resonance (SPR) spectroscopy and for their conformational properties by circular dichroism (CD). We find that the cyclic peptide of the integral Pt-binding sequence possesses single or 1:1 Langmuir adsorption behavior and displays equilibrium and adsorption rate constants that are significantly larger than those obtained for the linear form. Conversely, the linear form exhibits biexponential Langmuir isotherm behavior with slower and weaker binding. Furthermore, the structure of the cyclic version was found to adopt a random coil molecular conformation, whereas the linear version adopts a polyproline type II conformation in equilibrium with the random coil. The 2,2,2-trifluoroethanol titration experiments indicate that TFE has a different effect on the secondary structures of the linear and cyclic versions of the Pt binding sequence. We conclude that the presence of the Cys-Cys restraint affects both the conformation and binding behavior of the integral Pt-binding septapeptide sequence and that the presence or absence of constraints could be used to tune the adsorption and structural features of inorganic binding peptide sequences.     

Stability of S-layer proteins for electrochemical nanofabrication

Crystalline cell surface layer proteins (S-layers) can be used in electrochemical fabrication to create nanoscale arrays of metals and oxides on surfaces so long as the proteins maintain their long-range order during processing. We have explored the stability of the HPI layer protein (the S-layer protein from the microorganism Deinococcus radiodurans) adsorbed onto platinum surfaces after immersion in sulfuric acid or sodium hydroxide electrolytes ranging in pH from 0 to 14 over time periods ranging from 1 to 1000 s. Topographic data obtained by atomic force microscopy (AFM) was used to characterize the protein stability, judged by its retention of long-range order after immersion. The compiled data revealed that, under these solution conditions and in this environment, the HPI layer protein has a dose-dependent structural stability “envelope” in the acidic range from 1 < pH < 4. The protein retains its long-range order up to 1000 s from pH 4 to 11, and has a sharp stability edge between pH 12 and 13. Interestingly, the more stringent requirement of stability (i.e., retention of long-range order) defined in the context of electrochemical fabrication for this protein narrowed the window of stability in pH and time when compared to previous stability studies reported for this protein.     

Antibacterial, Antiurease, and Antioxidant Activities of Some Arylidene Barbiturates

Some series of arylidene barbiturates and thiobarbiturates were evaluated for their antibacterial, antioxidant, and urease inhibition activities. The arylidene barbiturates and thiobarbiturates were tested for antimicrobial activity using the agar well diffusion technique against 13 bacteria. The synthesized compounds (1a–g) were screened for antiurease and antioxidant activities. The results showed that the synthesized compounds (1a–g) had effective antiurease, antioxidant, and antibacterial activities.