Bacillus spp. cause ropy bread spoilage of bread, which is characterized by a rotten fruity odor, followed by discoloration and degradation of the crumb. Bacillus spp. are wheat grain endophytes and form heat resistant endospores, therefore, process hygiene and heating during baking do not prevent ropy spoilage. This study used 8 strains of Bacillus subtilis and Bacillus amyloliquefaciens to determine whether the presence and the copy number of spoVA^2mob operon influences survival after baking; in addition, the spoilage phenotype was correlated with the presence of amylolytic enzymes in genomes of Bacillus spp.. The presence and copy number of the spoVA^2mob operon had only a minor effect on survival of Bacillus endospores. Strains of B. amyloliquefaciens caused ropy spoilage faster than strains of B. subtilis, this difference correlated to the number and type of extracellular amylases encoded in the genomes of the strains of B. amyloliquefaciens and B. subtilis. The inhibitory effect of sourdough on ropy spoilage was determined by addition of 3–24% sourdough fermented with L. reuteri TMW1.656. Addition of 12% and 24% sourdough, corresponding to a bread pH of 5.93 ± 0.041 and 5.53 ± 0.040, respectively, delayed ropy spoilage for 2 and more than 5 d, respectively. The comparison of addition of 12% sourdough fermented with the reutericyclin producing L. reuteri TMW1.656 and the isogenic reutericyclin-negative strain L. reuteri TMW1.656ΔgtfAΔrtcN demonstrated that reutericyclin produced in sourdough inhibits growth of Bacillus in bread. In conclusion, sourdough inhibits germination of Bacillus spores in bread and the effect of sourdough is enhanced by reutericyclin.

芽孢杆菌属。导致面包的面包变质，其特征是腐烂的果味，随后面包屑变色和降解。芽孢杆菌属。属于小麦籽粒内生菌，可形成耐热的内生孢子，因此，烘烤过程中的过程卫生和加热不能防止腐烂。本研究中使用8个菌株的枯草芽孢杆菌和地衣芽孢杆菌，以确定是否存在和拷贝数spoVA ^2mob烘焙后操纵子的影响存活; 此外，腐败表型与芽孢杆菌属基因组中淀粉分解酶的存在有关。spoVA ^2mob的存在和拷贝数操纵子对芽孢杆菌内生芽孢杆菌的存活只有很小的影响。的菌株解淀粉芽孢杆菌引起的粘稠变质的速度比的菌株B.小号ubtilis，这种差异相关的在菌株的基因组编码的胞外淀粉酶的数量和类型解淀粉芽孢杆菌和B.小号ubtilis。通过添加3–24％的路氏乳杆菌发酵酵母来确定面团对腐烂变质的抑制作用TMW1.656。添加12％和24％的酵母粉，分别对应于面包的pH为5.93±0.041和5.53±0.040，分别使ropy变质延迟了2天和5天以上。另外12％的酵母与reutericyclin生产发酵的的对比罗伊氏乳杆菌TMW1.656和同基因reutericyclin阴性菌株罗伊氏TMW1.656Δ GTFA Δ RTCN证明的酵母抑制生长产生的reutericyclin芽孢杆菌中的面包。总之，面团抑制面包中芽孢杆菌孢子的萌发，而路透环素可增强面团的作用。