Predicting microbial growth in pulp using an electronic tongue

• This paper describes how an electronic tongue based on pulsed voltammetry over noble metal electrodes can be used as an instrument to predict the amount of microorganisms in pulp during their growth cycle. The electronic tongue consists of a sensor body and a PC, which is used to control a potentiostat which applies the voltammetric large amplitude pulsed voltammetry (LAPV)-waveform across the sensor electrodes, and to collect the data of the resulting current. The sensor body is constructed of four noble metal electrodes, a stainless steel electrode as counterelectrode, and an Ag/AgCl reference electrode. This arrangement works as a standard three-electrode voltammetry system. Principal component analysis (PCA) and partial least squares (PLS) multivariate prediction methods are used to extract information from the data and to aid interpretation. It is shown that PLS-models of the voltammetric signals from this sensor array predicts the reference methods, viable count using Petrifilm(TM) aerobic total counts, with good accuracy (root mean square error of prediction (RMSEP) 9% of maximum value or 20% in a lower region corresponding to 500-1000 colony forming units) and adenosine triphosphate (ATP)-measurements with lower accuracy (10% of maximum value or 55% in a lower region). Since the precision of this method of detection is on a level with the viable count method, this method can be considered superior where short response times or the possibility of on-line measurement are of value.

Keyword

pulp

microbiology

electronic tongue

voltammetry

multivariate data analysis

TECHNOLOGY

TEKNIKVETENSKAP

Publication and Content Type

ref (subject category)

art (subject category)