Aspergillus Species Discrimination Using a Gas Sensor Array

Abstract

The efficiency of electronic noses in detecting and identifying microorganisms has been proven by several studies. Since volatile compounds change with the growth of colonies, the identification of strains is highly dependent on the growing conditions. In this paper, the effects of growth were investigated with different species of Aspergillus, which is one of the most studied microorganisms because of its implications in environmental and food safety. For this purpose, we used an electronic nose previously utilized for volatilome detection applications and based on eight porphyrins-functionalized quartz microbalances. The volatile organic compounds (VOCs) released by cultured fungi were measured at 3, 5, and 10 days after the incubation. The signals from the sensors showed that the pattern of VOCs evolve with time. In particular, the separation between the three studied strains progressively decreases with time. The three strains could still be identified despite the influence of culture time. Linear Discriminant Analysis (LDA) showed an overall accuracy of 88% and 71% in the training and test sets, respectively. These results indicate that the presence of microorganisms is detectable with respect to background, however, the difference between the strains changes with the incubation time.

Application of a Low-Cost Electronic Nose for Differentiation between Pathogenic Oomycetes Pythium intermedium and Phytophthora plurivora

“…Some other research in similar fields of fungal odors detection should be acknowledged. Recently Guo and coworkers [ 19 ] reported studies of Penicillium expansum spoilage of apples, Capuano et al [ 20 ] studied Aspergillus species discrimination using a gas sensor array, Loulier et al [ 21 ] studied various fungi species using gas chromatography and a differential electronic nose device. Wang et al [ 22 ] studied volatile organic compound emitted by Phytophthora cactorum infected strawberries by a newly constructed bioelectronic nose based on single-stranded DNA and a single-walled carbon nanotube.…”

Light-Activated Porphyrinoid-Capped Nanoparticles for Gas Sensing

“…40 This property is well known, and has been fully exploited in quartz microbalance sensors, where arrays made of porphyrinoids with different molecular structures show a selectivity pattern sufficient for electronic nose applications in varied fields, such as medical diagnosis 7 41 and microbial contamination. 42 .…”

A Potentiometric Electronic Tongue as a Discrimination Tool of Water-Food Indicator/Contamination Bacteria

“…However, the industrial use of such instruments in detecting food spoilage or the presence of pathogenic microorganisms is still at the early stages and some technical drawbacks still need to be addressed, as reviewed by Ghasemi-Varnamkhasti et al [19]. As recently pointed out, electrochemical sensor devices, such as electronic noses (E-noses) [20,21] and electronic tongues (E-tongues) [22], are the basis of a wide number of low-cost and fast response analytical strategies for the analysis of gas and liquid matrices, respectively. E-tongues based on different sensing technologies (e.g., potentiometric, voltammetric), comprising sets of multisensors with low selectivity and cross-sensitivity, together with multivariate qualitative and quantitative chemometric tools (e.g., principal component analysis (PCA); soft independent modelling of class analogy (SIMCA); linear discriminant analysis (LDA); partial least-squares regression (PLS); support vector machines (SVMs); artificial neural networks (ANNs)) have been successfully applied to directly or indirectly identify several microorganisms.…”