4/6/2023 0 Comments Spova a universal time![]() ![]() Notable differences have been observed with respect to the spore wet heat resistance properties of strains within the B. licheniformis, it is critical to control these spores in the food chain ( Madslien et al., 2013). Due to the pathogenic potential of strains of B. Lichenisyn is a non-ribosomally synthesized lipo-peptide that is heat-stable ( Konz et al., 1999). licheniformis can produce a toxin, lichenisyn A, that can cause foodborne illness ( Salkinoja-Salonen et al., 1999 Nieminen et al., 2007 Logan, 2012). amyloliquefaciens may spoil bread, resulting in ropy bread by degradation of starch and the formation of extracellular polysaccharides ( Sorokulova et al., 2003 Valerio et al., 2012, 2015). licheniformis may be present in milk and milk powders leading to spoilage of heat treated dairy products ( Gopal et al., 2015), and B. subtilis, for instance has been reported to be present in cocoa ( Lima et al., 2011) leading to spoiled chocolate drinks, B. licheniformis can result in spoiled food products. After spore survival, germination, and outgrowth, vegetative cells of B. These species are for instance well-known contaminants of raw materials used in bread making ( Rosenkvist and Hansen, 1995 Sorokulova et al., 2003), and the spores can potentially even survive the bread baking process ( Valerio et al., 2015). ![]() ![]() licheniformis are commonly found in various food ingredients and food products including cocoa, herbs, spices, bread, soups, milk, and milk powders ( te Giffel et al., 1996 Oomes et al., 2007 Lima et al., 2011 Lücking et al., 2013 Miller et al., 2015). These species can generally grow between temperatures of 30–50☌, with reported growth temperatures of B. sonorensis, which are phylogenetically close, yet distinguishable ( Logan and Vos, 2009). subtilis group encompasses the species B. ![]() subtilis group are commonly found in various food ingredients and food products. Spores of mesophilic species belonging to the B. Surviving spores may germinate upon exposure to certain environmental triggers, and can subsequently resume vegetative growth, potentially resulting in food pathogenicity or food spoilage, depending on the species ( Scheldeman et al., 2006 Wells-Bennik et al., 2016). Such treatments put selective pressure on the microflora that is present, allowing for survival of those strains that produce spores with high heat resistance ( Postollec et al., 2012). The intrinsic resistance properties of spores may result in survival during food processing, in which heating is one of the most commonly applied treatments to reduce bacterial loads. Bacterial spores can enter the food chain from many different sources, for example via soil, dust, and biofilms ( Heyndrickx, 2011). The ubiquitous presence of bacterial spore formers in nature can be largely attributed to their ability to produce endospores (spores) that can survive harsh environmental conditions ( Nicholson et al., 2000 Setlow, 2006). licheniformis strains that produce highly heat resistant spores in the food chain. The findings presented in this study allow for detection of B. licheniformis that contain the Tn 1546 elements (and produce high-level heat resistant spores) grew at temperatures similar to those of their Tn 1546-negative counterparts that produce low-level heat resistant spores. Assessment of growth of the nine strains of each species between 5.2☌ and 57.7☌ showed some differences between strains, especially at lower temperatures, but all strains were able to grow at 57.7☌. licheniformis are responsible for high level heat resistance of spores. subtilis 168 (producing spores that are not highly heat resistant) rendered mutant 168 strains that produced high-level heat resistant spores, demonstrating that these elements in B. Introduction of these spoVA 2mob operons into B. In this study, the locations and compositions of Tn 1546 transposons encompassing the spoVA 2mob operons in B. Such Tn 1546 transposon elements including the spoVA 2mob operon were also found in several strains of Bacillus amyloliquefaciens and Bacillus licheniformis, and these strains were shown to produce spores with significantly higher resistances to wet heat than their counterparts lacking this transposon. Recently, it was shown that a spoVA operon, designated spoVA 2mob, present on a Tn 1546 transposon in Bacillus subtilis, leads to profoundly increased wet heat resistance of B. Some spores may survive heating processes aimed at production of commercially sterile foods. 2Laboratory of Molecular Genetics, University of Groningen, Groningen, Netherlandsīacterial endospore formers can produce spores that are resistant to many food processing conditions, including heat.1Top Institute Food and Nutrition, Wageningen, Netherlands.Koning 1,3, Jos Boekhorst 1,3, Anne de Jong 1,2, Oscar P. ![]()
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