Evaluation of different growth media for the recovery of the species of Alicyclobacillus.
OBJECTIVE
Five different isolation media, namely potato dextrose agar (PDA), orange serum agar (OSA), K agar, yeast-starch-glucose agar and Bacillus acidocaldarius medium were evaluated for the recovery of Alicyclobacillus spp. from inoculated diluted and undiluted fruit-juice concentrates.


RESULTS
Plates of PDA (pH 3.7), spread with vegetative cells (3.9 x 10(6) CFU ml(-1)) of Alicyclobacillus acidoterrestris from single-strength pear juice, recovered 2.9 x 10(6 )CFU ml(-1) after 5 days at 50 degrees C (74% recovery). The recovery of endospores from single-strength pear juice, after a heat treatment at 80 degrees C for 10 min, was higher on spread plates of OSA (pH 5.5) at 50 degrees C for 5 days (97% recovery).


CONCLUSIONS
PDA (pH 3.7) and OSA (pH 5.5) at 50 degrees C for 3-5 days recovered the highest numbers of vegative cells and endospores of Alicyclobacillus spp. from sterilized fruit juices and concentrates.


CONCLUSIONS
The most appropriate synthetic media for the recovery of Alicyclobacillus species from inoculated fruit juices and concentrates are shown.
Witthuhn
R C
RC
Department of Food Science, Stellenbosch University, Stellenbosch, Matieland, 7602, South Africa. rcwit@sun.ac.za
Duvenage
W
W
Gouws
P A
PA
D000362:Agar; D001431:Bacteriological Techniques; D001628:Beverages / Q000382:microbiology*; D003470:Culture Media; D016936:Gram-Positive Endospore-Forming Bacteria / Q000145:classification* / Q000254:growth & development / Q000302:isolation & purification*; D006863:Hydrogen-Ion Concentration; D013045:Species Specificity; D013696:Temperature; D027843:Vitis / Q000382:microbiology*
D003470:Culture Media; D000362:Agar