BACKGROUND Although lovastatin production has been reported for different microorganism species, there is limited information about lovastatin production by basidiomycetes. AIMS The optimization of culture parameters that enhances lovastatin production by Omphalotus olearius OBCC 2002 was investigated, using statistically based experimental designs under solid state fermentation. METHODS Th...

A rapid and sensitive method has been proposed for the determination of chromium and cobalt in seafood samples by flame atomic absorption spectrometry combined with a dynamic ultrasound-assisted acid extraction and an on-line minicolumn preconcentration. The use of diluted nitric acid as extractant in a continuous mode at a flow rate of 3.5 mL min(-1) and room temperature was sufficient for qua...

In this article we investigate two-level split-plot designs where the sub-plots consist of only two mirror image trials. Assuming third and higher order interactions negligible, we show that these designs divide the estimated effects into two orthogonal sub-spaces, separating sub-plot main effects and sub-plot by whole-plot interactions from the rest. Further we show how to construct split-plot...

The aim of this study was to enhance the production of vitamin K2 by using N-methyl-N-nitro-N-nitroso-guanidine (NTG) and low energy ion beam implantation and optimizing the fermentation medium. Mutation resulted in 1.66fold higher production of vitamin K2 than that of the parentl strain. The production by the mutant BN-P15-11-1 was increased 55% and reached 3.593±0.107 mg/L by using the Placke...

An HS-SPME method was developed using multivariate experimental designs, which was conducted in two stages. The significance of each factor was estimated using the Plackett-Burman (P-B) design, for the identification of significant factors, followed by the optimization of the significant factors using central composite design (CCD). The multivariate experiment involved the use of Minitab® stati...

We study the problem of collaborative filtering where ranking information is available. Focusing on the core of the collaborative ranking process, the user and their community, we propose new models for representation of the underlying permutations and prediction of ranks. The first approach is based on the assumption that the user makes successive choice of items in a stage-wise manner. In par...

The bacterial strain producing thermostable, alklophilic alpha-amylase was identified as Bacillus amyloliquefaciens KCP2 using 16S rDNA gene sequencing data (NCBI Accession No: KF112071). Medium components were optimized through the statistical approach for the synthesis of alpha-amylase by the organism under solid-state fermentation using wheat bran as the substrate. The medium components infl...

Due to cost, time, and flexibility constraints, simulators are often used to explore the design space when developing new processor architectures, as well as when evaluating the performance of new processor enhancements. However, despite this dependence on simulators, statistically rigorous simulation methodologies are not typically used in computer architecture research. A formal methodology c...

In this study, an analytical methodology based on a combination of dispersive liquid–liquid microextraction with laser-induced breakdown spectrometry was evaluated for simultaneous pre-concentration, speciation and detection of Cr. The microextraction procedure was based on the injection of appropriated quantities of 1-undecanol and ethanol into a sample solution containing the complexes formed...

Response surface methodology was engaged for the optimization of diverse nutritional and physical parameters for laccase production by Streptomyces chartreusis strain NBRC 12753 in the submerged fermentation process. Screening of production parameters was executed using Plackett–Burman design and the variables with statistically momentous effects on laccase production were recognized. Variables...