Microbial and Hybrid Sensors for Determination of α-Amylase Activity

The Microbial Cell Based Biosensors

“…The results obtained supposed the possibility of selectivity improving using differential measurement principle (Makarenko et al, 1999). The hybrid biosensor creation is also related to a number of methods of selectivity improving (Renneberg et al, 1984). In this case only one of simultaneously immobilized biocatalysts carries out the reaction registered by a transducer; actually, it's selectivity determines the total selectivity of a system.…”

“…Maybe this explains the small amount of hybrid microbial sensors described to date. The hybrid sensor containing Bacillus subtilis cells in combination with the glucoamylase for the evaluation of -amylase activity was reported in (Renneberg et al, 1984). The hybrid biosensor analyzer using the combination of the enzymes and bacterial cells and the column-type reactor with the membrane receptor was presented in publication (Reiss et al, 1998).…”

“…The effect can be used for selective determination of the substances in a mixed sample. One of the most common ways of the microbial sensor selectivity improving consists in the cultivation of the biomass at a later stage used in a bioreceptor with the expected analyte as a sole source of carbon and energy or as a co-substrate (Simonian et al, 1992;Renneberg et al, 1984). The approach does not eliminate the ability of a sensor to respond to a wide spectrum of substances.…”

“…The approach does not eliminate the ability of a sensor to respond to a wide spectrum of substances. It only allows to selectively increase (Renneberg et al, 1984) the sensor sensitivity to the analyte as a result of the induction and expression of the enzymes responsible for its conversion. The popular modification of the approach is the case when the biosensor or biomass after cultivation has been incubated with the analyte (Racek & Musil, 1987a;Riedel et al, 1990b).…”

“…Two hybride carbohydrate sensors were mentioned above (Svitel et al, 1998); besides them the hybrid sensors for sucrose determination based on invertase and Z. mobilis cells (Park et al, 1991) and for detection of lactose in dairy products based on glucose oxidase and E. coli cells (Svorc et al, 1990) have also been reported. The same approach was used for determination of -amylase activity using co-immobilized B. subtilis and glucoamylase (Renneberg et al, 1984). Another manuscript describes an automated system based on a reactor containing the immobilized cells of Rhodococcus erythropolis and Isaatchenkia orientalis and screen printed oxygen electrodes (Heim et al, 1999).…”