Gunter Saunders

Integrating Technology into a Traditional Learning Environment Reasons for and Risks of Success

This article reports on an evaluation of student views and reactions to a changed approach to teaching and learning that was enabled by the extensive use of information and communication technology (ICT). Evaluation was carried out over two academic years and involved the use of questionnaires, one-to-one interviews with students and student-led discussions. In general, students were appreciative of the approach, welcoming classroom sessions that focused on real problem-solving rather than one-to-many discourse. The students perceived the module to be harder than other modules although overall student performance was actually better when compared with previous years. It was clear, however, that during the semester most students used the electronic materials provided only when they needed them to support coursework assignments. As a consequence one major aim of the approach, to increase the degree of student-led learning in class, was not achieved consistently.

Factors affecting faculty use of learning technologies: implications for models of technology adoption

This study examines factors associated with the use of learning technologies by higher education faculty. In an online survey in a UK university, 114 faculty respondents completed a measure of Internet self-efficacy, and reported on their use of learning technologies along with barriers to their adoption. Principal components analysis suggested two main barriers to adoption: structural constraints within the University and perceived usefulness of the tools. Regression analyses indicated both these variables, along with Internet self-efficacy, were associated with use of online learning technology. These findings are more consistent with models of technology engagement that recognize facilitating or inhibiting conditions (unified theory of acceptance and use of technology; decomposed theory of planned behavior) than the classic technology acceptance model (TAM). Practical implications for higher education institutions are that while faculty training and digital literacy initiatives may have roles to play, structural factors (e.g., provision of resources and technical support) must also be addressed for optimal uptake of learning technologies.

Heterologous gene expression in filamentous fungi

Abstract Filamentous fungi are central to a broad spectrum of activities in industrial microbiology. They have been used for decades in the elaboration of a wide range of compounds including antibiotics and organic acids. They are also prodigious producers of enzymes which are used, for example, in the production of soy sauce, in cheese ripening and in the biocatalytic conversion of starch to glucose. Two species of filamentous fungi, Aspergillus nidulans and Neurospora crassa , have been the subjects of sophisticated genetic and biochemical analyses for a number of years. In this article we discuss the recent progress made in the use of filamentous fungi as hosts for the expression of foreign genes, highlighting their established and potential advantages for the production of proteins of therapeutic and/or commercial significance.

High-performance liquid chromatographic determination of β-lactam antibiotics, using fluorescence detection following post-column derivatization

Abstract This paper describes a rapid, sensitive and specific technique for the determination in microbial fermentation broths of several naturally produced β-lactams. The method consists of reversed-phase, high-performance liquid chromatographic separation of the antibiotics on an octylsilane chemically bonded stationary phase. This is followed by reaction with o-phthaldialdehyde and quantitative spectrofluorimetric detection. Post-column reaction conditions including temperature, reagent pH, flowrates and reactor coil length are investigated. Accuracy, reproducibility and detection limits of the method are also examined. The technique is applied to the analysis of fermentation media following sample preparation by centrifugation and filtration.

Rapid and quantitative analysis of metabolites in fermentor broths using pyrolysis mass spectrometry with supervised learning : application to the screening of Penicillium chrysogenum fermentations for the overproduction of penicillins

Abstract The combination of pyrolysis mass spectrometry (PyMS) and artificial neural networks (ANNs) can be used to quantify levels of penicillins in strains of Penicillium chrysogenum and ampicillin in spiked samples of Escherichia coli. Four P. chrysogenum strains (NRRL 1951, Wis Q176, P1, and P2) were grown in submerged culture to produce penicillins, and fermentation samples were taken aseptically and subjected to PyMS. To deconvolute the pyrolysis mass spectra so as to obtain quantitative information on the titre of penicillins, fully-interconnected feedforward artificial neural networks (ANNs) were studied; the weights were modified using the standard back-propagation algorithm, and the nodes used a sigmoidal squashing function. In addition the multivariate linear regression techniques of partial least squares regression (PLS), principal components regression (PCR) and multiple linear regression (MLR) were applied. The ANNs could be trained to give excellent estimates for the penicillin titre, not only from the spectra that had been used to train the ANN but more importantly from previously unseen pyrolysis mass spectra. All the linear regression methods failed to give accurate predictions, because of the very variable biological backgrounds (the four different strains) in which penicillin was produced and also of the inability of models using linear regression accurately to map non-linearities. Comparisons of squashing functions on the output nodes of identical 150-8-1 neural networks revealed that networks employing linear functions gave more accurate estimates of ampicillin in E. coli near the edges of the concentration range than did those using sigmoidal functions. It was also shown that these neural networks could be successfully used to extrapolate beyond the concentration range on which they had been trained. PyMS with the multivariate clustering technique of principal components analysis was able to differentiate between four strains of P. chrysogenum studied, and was also able to detect phenotypic differences at five, seven, nine or 11 days growth. A crude smapling procedure consisting of homogenised agar plugs proved applicable for rapid analysis of a large number of samples.

Derivatization techniques for high-performance liquid chromatographic analysis of β-lactams

Abstract High-performance liquid chromatographic techniques are described for the determination of β-lactam antibiotics. Reversed-phase chromatography is performed on a chemically bonded silica support, often employing a mobile phase containing an organic modifier and ion-pairing reagent. Novel derivatization procedures are described, including pre-column reaction with an imidazole—metal salt reagent and post-column, fluorescent labelling with o-phthaldialdehyde. Each method is investigated and discussed in terms of sensitivity and chromatographic efficiency, with application to natural and semi-synthetic β-lactams.

Production of fructooligosaccharides byFusarium oxysporum

SummaryProduction of ß-fructosidases during growht of several fungi has been studied.F. oxysporum was found to produce fructosyltransferase and invertase in sufficient quantities to allow further studies of the differences in specificity of the two enzymes.

Development of a gene transfer system for Penicillium chrysogenum

SummaryWe report here the development of an endogenous gene transfer system for the industrially-important Deuteromycete Penicillium chrysogenum, utilising a recombinant plasmid designated pPC-31 to complement a tryptophan — auxotrophic strain. Transformation frequencies in the order of 300–1800 transformants per μg DNA have been obtained, and Southern hybridisation analysis has demonstrated that in the majority of cases, integration is mediated by homologous recombination between pPC-31 and the host genome at the site of the resident mutant allele.

Detection of a protein which binds specifically to the upstream region of the pcbAB gene in Penicillium chrysogenum

The upstream region of the pcbAB gene from Penicillium chrysogenum was screened for protein-binding sites using an electromobility shift assay. A specific protein/DNA interaction was detected within a fragment covering the region-387 to-242 relative to the pcbAB translational start codon. The appearance of this protein and pcbAB mRNA in culture extracts occurred at the same time point in fermentations, suggesting that the protein might be a transcription activator. The putative upstream activating sequence was located more precisely using cross-competition assays. These indicated the involvement of the 7-bp motif TGCCAAG in the binding of the protein.

N-Deglycosylation of fructosyltransferase and invertase from Fusarium oxysporum decreases stability but has little effect on kinetics and synthetic specificity

Most of the carbohydrate moiety of invertase and fructosyltransferase (FTF) from F. oxysporum IMI 172464 was removed by peptide-N-glycosidase F. The molecular weights of native invertase and FTF were 260 kDa and 210 kDa respectively. Deglycosylation lowered the molecular sizes by 42% and 23%, respectively. The K values for sucrose remained unchanged by deglycosylation. However the stability of both enzymes at their optimum pH (4.0 for invertase, 5.0 for FTF) and optimum temperature (45°C for invertase, 35°C for FTF) was decreased: their sensitivity to protease digestion was increased by 36% and 41%, respectively. The synthetic specificity of deglycosylated FTF remained unchanged. The carbohydrate moiety of invertase and FTF contributes to the stability of the enzymes but is not essential in their catalytic function and plays no part in determining their specificity.