Contribution of environmental factors in the formation of biofilms by Alicyclobacillus acidoterrestris on surfaces of the orange juice industry

EnglishThe objective of this study was to evaluate the effect of the initial microbial load, temperature and contact time on the biofilm formation of Alicyclobacillus acidoterrestris on stainless steel and natural food-grade rubber using orange juice as culture medium. The low initial load of A. acidoterrestris (2 log CFU/mL) led to biofilm formation on the stainless steel surface after 48 h of contact at 28 oC and after 24 h at 45 oC, and on natural food-grade rubber surface after 48 h of contact at both temperatures. The high initial microbial load (5 log CFU/mL) led to biofilm formation on stainless steel after 4 h of contact at 28 °C and 45 °C, while biofilm was formed on natural food-grade rubber after 8 h of contact at 28 °C and 4 h at 45 °C. The microbial load also affected the presence of spores in biofilm, which was observed on both surfaces only at high initial loads of A. acidoterrestris portuguesO objetivo deste estudo foi avaliar o efeito da carga microbiana inicial, temperatura e tempo de contato na formacao de biofilme de Alicyclobacillus acidoterrestris em aco inoxidavel e borracha natural de qualidade alimentar utilizando suco de laranja como meio de cultura. A baixa carga inicial de A. acidoterrestris (2 log UFC/mL) levou a formacao de biofilme na superficie do aco inoxidavel apos 48 h de contato a 28 oC e apos 24 h a 45 oC, e na superficie natural de borracha de qualidade alimentar apos 48 h de contato nas duas temperaturas. A alta carga microbiana inicial (5 log UFC/mL) levou a formacao de biofilme em aco inoxidavel apos 4 h de contato a 28 °C e 45 °C, enquanto o biofilme foi formado em borracha natural de qualidade alimentar apos 8 h de contato a 28 °C e 4 h a 45 °C. A carga microbiana tambem afetou a presenca de esporos no biofilme, o que foi observado em ambas as superficies apenas com altas cargas iniciais de A. acidoterrestris