Sporeforming bacteria in beer: Occurrence, diversity, presence of hop resistance genes and fate in alcohol-free and lager beers

Author(s)

Munford, Allan R. G. ; Alvarenga, Veronica O. ; do Prado-Silva, Leonardo ; Crucello, Aline ; Campagnollo, Fernanda B. ; Chaves, Rafael D. ; Oteiza, Juan M. ; Sant'Ana, Anderson S.

• Document type: Journal article
• Source: FOOD CONTROL; v. 81, p. 126-136, NOV 2017.
• Web of Science Citations: 2

Abstract

The aim of this study was to assess the occurrence of sporeforming bacteria in different types of beers (n = 163) and to assess the presence of hor genes in the isolates. Additionally, the study aimed to evaluate the fate of five representative sporeforming bacteria harboring horA and horC genes in alcohol-free and lager beers. Two hundred and sixty (n = 260) sporeforming bacteria belonging to eight different genera were isolated from beers, i.e., Bacillus (n = 118), Paenibacillus (n = 89) and Brevibacillus (n = 41), Lysinbacillus (n = 6), Cohnella (n = 3), Rummeliibacillus (n =1), Alicyclobacillus (n = 1), and Anoxybacillus (n = 1), respectively. A predominance of members within the Bacillus cereus sensu lato (n = 72; 27.1%), followed by B. megaterium (n = 18; 7%), P. validus (n = 16; 6.1%), P. humicus (n = 13; 5%), P. alginolyticus (n = 13; 5%) and Br. brevis (n = 13; 5%) was observed in beer samples analyzed. Only 5% (n =14) out of 260 sporeforming bacterial isolates recovered from beers harbored one or both horA and horC genes. Only one (0.3%) isolate, i.e., Bacillus cereus sensu lato (identified as B. thuringiensis LMQA 206) presented both horA and horC genes. None of the five bacterial sporeforming strains harboring horA or horC genes inoculated was able to grow in the beers throughout the storage period studied, and no spoilage was detected. The results of this study indicated a widespread occurrence of sporeforming bacteria in several types of beers from different brands, highlighting that measures should be taken to reduce the occurrence of sporeforming bacteria considering stability and safety concerns. (C) 2017 Elsevier Ltd. All rights reserved. (AU)

• FAPESP's process: 14/17387-8 - Identification and functional analysis of new genes and regulatory elements implicated in the survival and persistence of Salmonella enterica in low-water activity food
• Grantee: Aline Crucello
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 14/14891-7 - Modelling the inhibition of Listeria monocytogenes by lactic acid bacteria (LAB) in traditional Minas cheeses
• Grantee: Fernanda Bovo Campagnollo
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 14/03791-1 - Stochastic Single Cell Modeling of Biofilm Formation and Inactivation by Sanitizers of Salmonella and Listeria monocytogenes and their Impacts on Food Safety
• Grantee: Rafael Djalma Chaves
• Support Opportunities: Scholarships in Brazil - Post-Doctoral