Characterisation of two novel cyclodextrinases using on-line microdialysis sampling with high-performance anion exchange chromatography

Recent discoveries and applications of Anoxybacillus

The Bacillaceae family members are a good source of bacteria for bioprocessing and biotransformation involving whole cells or enzymes. In contrast to Bacillus and Geobacillus, Anoxybacillus is a relatively new genus that was proposed in the year 2000. Because these bacteria are alkali-tolerant thermophiles, they are suitable for many industrial applications. More than a decade after the first report of Anoxybacillus, knowledge accumulated from fundamental and applied studies suggests that this genus can serve as a good alternative in many applications related to starch and lignocellulosic biomasses, environmental waste treatment, enzyme technology, and possibly bioenergy production. This current review provides the first summary of past and recent discoveries regarding the isolation of Anoxybacillus, its medium requirements, its proteins that have been characterized and cloned, bioremediation applications, metabolic studies, and genomic analysis. Comparisons to some other members of Bacillaceae and possible future applications of Anoxybacillus are also discussed.

Detection of in vivo matrix metalloproteinase activity using microdialysis sampling and liquid chromatography/mass spectrometry

Matrix metalloproteinases (MMPs) are a family of endoproteases that break down extracellular matrix and whose upregulation contributes to several diseases. A liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was developed to quantify MMP-1 and MMP-9 substrates and their N-terminal peptide products in samples obtained from implanted microdialysis sampling probes. In vitro studies with purified human MMP-1 and MMP-9 were used to optimize the assay and determine the effectiveness of the local delivery of a broad-spectrum MMP inhibitor, GM 6001. Localized delivery of GM 6001 at 10 microM was sufficient to completely inhibit product formation in vitro. In vivo studies in male Sprague-Dawley rats were performed with microdialysis probes implanted into the subcutaneous tissue. Directly after microdialysis probe implantation, infusions of the MMP-1 and MMP-9 substrates (50 microM each) resulted in recovered product concentrations of approximately 2 microM. During a 50 microM GM 6001 coinfusion with the substrates, a 30% and 25% reduction in product formation for the MMP-1 and MMP-9 substrates was obtained, respectively. Blank dialysates were negative for enzymatic activity that could cleave the MMP substrates. This method allowed for the activity of different MMPs surrounding the microdialysis probe to be observed during in vivo sampling.

Current separation and detection methods in microdialysis the drive towards sensitivity and speed

This review outlines some of the analytical challenges associated with the analysis of microdialysis (MD) samples, in particular, the minute complex sample volumes that are often encountered. In MD sampling many different low-molecular-weight molecules can be collected, but the research findings are often limited by the sensitivity, specificity, and reliability of the analytical technique that is coupled to the dialysis probe. Therefore it is critical that a lot of consideration is given in selecting the most suitable analytical method including the most appropriate detector. This review aims to highlight the strengths and weaknesses of a range of commonly used analytical methods employed in MD. In Section 1, a brief overview of the MD technique is described, followed by a discussion on some of the advantages and drawbacks of this sampling technique. Sections 2 and 3 examine analytical and other technical considerations regarding analysis, with special emphasis on the factors that specifically influence analytical detection. Section 4 outlines the most commonly employed analytical techniques used in MD, including HPLC coupled with various detectors. Detail is given regarding the LOD and LOQ for many applications using each detector. As MS is of such high importance in MD, a special sub-section has been devoted to it. The importance of CE is also highlighted, with specific applications described. In addition, analytical techniques that do not appear to have found routine use in MD are discussed. Section 5 is concerned with recent innovations in chemical separation techniques, in particular MCE and ultra-performance liquid chromatography. Specific applications of the coupling of these techniques with MD are highlighted, along with technical challenges associated with miniaturization. In the Section 6, the future outlook of MD is discussed. Techniques other than electrophoretic- and chromatographic based separation methods are outside the scope of this review.