Isolation and identification of Alicyclobacillus acidocaldarius by 16S rDNA from mango juice and concentrate

• Published in: International journal of food science & technology Vol. 40; no. 7; pp. 789 - 792
• Main Authors: Gouws, P.A, Gie, L, Pretorius, A, Dhansay, N
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Ltd 01.08.2005; Blackwell Science
• Subjects: 16S rDNA; Alicyclobacillus; Alicyclobacillus acidocaldarius; aseptic packaging; bacterial contamination; Biological and medical sciences; carbonated beverages; food contamination; Food industries; food pathogens; food spoilage; Fruit and vegetable industries; fruit juices; Fundamental and applied biological sciences. Psychology; juice concentrates; mango juice; mangoes; molecular sequence data; nucleotide sequences; pasteurization; pathogen identification; polymerase chain reaction; ribosomal DNA; spoilage; UHT treatment; Fruit; Mangifera indica; Mango; Identification; mango juice; spoilage; Alicyclobacillus; 16S rDNA; Dicotyledones; Angiospermae; Isolation; Spermatophyta; Concentrate; Anacardiaceae
• ISSN: 0950-5423; 1365-2621
• DOI: 10.1111/j.1365-2621.2005.01006.x

In this study we investigate the spoilage of ultra high temperature UHT mango juice as well as a carbonated fruit juice blend to identify organisms contributing to the spoilage. The mango concentrate, the final product, as well as the other ingredients used during manufacturing, were tested for the presence of Alicyclobacillus by polymerase chain reaction (PCR) and sequencing analyses. Microbiological examination of the mango pureé and spoiled fruit juices, using YSG agar [yeast extract 2 g, glucose 1 g, soluble starch 2 g, pH 3.7 (adjust with 2N H2SO4), H2O 1000 mL, bacto agar 15 g] incubated at 55 °C, detected sporeforming, acid dependent and thermotolerant bacteria. The hyper variable region of the 16S rDNA was amplified. The nucleotide sequence of the PCR fragments was determined using the ABI Prism 310 automated DNA sequencer and the collected sequencing data were analysed and compared with the non-redundant database using NCBI-BLAST. Alicyclobacillus acidocaldarius were isolated and identified by 16S rDNA gene sequences analyses. The results indicated that the mango purèe, as well as the final product of mango juice and the fruit juice blend, were positive for Alicyclobacillus. The preventative measures of low pH, pasteurization of mango juice and the subsequent use of aseptic packaging were not regarded as sufficient to prevent the outgrowth of Alicyclobacillus spoilage organisms.