Phage contamination is one of the significant problems in the food fermentation industry, which eventually causes economic losses to the industry. Here, we investigated the viability of Lactobacillus plantarum phage P1 and P2 using various biocides treatments (ethanol, isopropanol, sodium hypochlorite and peracetic acid). Results indicated that phage P1 and P2 could be completely inactivated by treatment with 75% ethanol for 5 min, followed by 400 ppm of sodium hypochlorite treatment for 5 min. Phage P2 could be completely inactivated in the reverse sequence, while 800 ppm of sodium hypochlorite was required to achieve a similar effect for phage P1. Moreover, 100% isopropanol could increase the inactivating effect of 75% ethanol. This study may provide basic information on using multiple antimicrobials for phage control in laboratories and food plants.

Bacillus species have been widely used as probiotics in a number of food products. However, these are vulnerable to bacteriophage infections which poses fermentation failure and eventually result in economic losses. Given this, we designed this study in which bacteriophage of lysogenic Bacillus methylotrophicus, Phage BM-P, was induced successfully, and its biological characteristics and genome information were researched. The obtained results showed that Bacillus species phage belonged to Myoviridae family. The maximum number of infections (MOI) for this phage was 10, with a burst size of 104.48 ± 2.70 counts expressed per milliliter per infective center. Additionally, this phage was temperature and pH sensitive and divalent ions (Ca 2+, Mg 2+) and chloramphenicol did not express significant influence on its adsorption capacity. Genomic analysis revealed that the genome size of Phage BM-P1 was 153,087 bp having 41.94% GC content, including 258 coding sequences (CDs). Further, 52 bacteriophages of Bacillus were classified into two clades by using phylogenetic analysis. Among them, phage BM-P1 with phage VB_BsuM-Goe3 and vB_BveM-Goe7 had highest ANI values, 95.23% and 95.28%, respectively. However, synteny analysis unraveled transpose, deletion and insertion in the genome of BM-P1. Considering this, it could be extrapolated that this phage is a new lysogenic phage. In conclusion, this study furthers the knowledge on the properties of Bacillus methylotrophicus phages and provides seminal insights for designing effective antiphage strategies for fermentation industry.