Inativação de Alicyclobacillus acidoterrestris por saponinas e detecção por reação em cadeia da polimerase por transcrição reversa (RT-PCR) / Inativation of Alicyclobacillus acidoterrestris by saponins and detection by reverse transcriptase polymerase chain reaction (RT-PCR)

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

Alicyclobacillus acidoterrestris are termoacidophilic sporeforming nonpathogenic bacteria who are commonly present in acidic fruit juices and can deteriorate them. In view of the importance of agricultural activities in the country and its derivatives, such as industrialized orange juice the interest in the development of bioanalitycal techniques that provide early, sensitive, and reliable detection, as well as alternatives to inactivate the microorganism is elevated. This study tested the use of saponins as an inhibitor of spores and vegetative cells of A. acidoterrestris in both concentrate and reconstituted orange juices. At room temperature, however, the inhibition is slow, especially for spores (about 10 days for a total inhibition), preventing its use in the citrus industry. The combination of heat treatment and saponins potentiated the inhibition of bacteria, which makes possible their industrial application. Optimizing the temperature reached 20% for spores in juice concentrate, 28.5% for spores in reconstituted juice and 45.1% for vegetative cells in reconstituted juices. Detection of cell viability was performed by reverse transcription polymerase chain reaction (RT-PCR), which showed to be a fast, sensitive, and quantitative equivalent to the traditional plating technique, and the correlation coefficient (r) between the techniques were 0.9977 and 0.9987 for spores and vegetative cells, respectively. The quantification of the products of RT-PCR was performed by capillary electrophoresis on microchip with Bioanalyzer 2100 equipment. The equipment provided reliable and reproducible results for the diagnosis of DNA transcript of A. acidoterrestris. Besides of high sensitivity, the equipment allowed minimal consumption of sample (1 μL) and provided convenience and speed of analysis.

ASSUNTO(S)

alicyclobacillus acidoterrestris alicyclobacillus acidoterrestris rt-pcr saponins saponinas rt-pcr

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