The peptide antibiotics from the polymyxin–colistin–circulin family (Vogler & Studer, 1966) are active against Gram-negative bacteria; other peptides, such as polypeptins (Sogn, 1976), jolipeptin (Ito & Koyama, 1972), gavaserin and saltavalin

(Pichard et al., 1995), are active against both Gram-negative and Gram-positive bacteria. The second group includes antibiotics such as gatavalin (Nakajima et al., 1972), fusaricidins (Kajimura & Kaneda, 1996, 1997; Beatty & Jensen, 2002) and LI-F complex (Kurusu et al., 1987), which are active against fungi, actinomycetes and Gram-positive bacteria. Bacteriophage infection of starter cultures remains a significant problem in fermentation BTK inhibitor industries. Many bacteriophages are active against strains of the genus Paenibacillus. Most frequently reported are the bacteriophages infecting P. polymyxa and Paenibacillus larvae, and only a few bacteriophages from P. Torin 1 ic50 polymyxa strains have been described in detail thus far. Francis & Rippon (1949) were first to report isolation of four bacteriophages infecting the members of this species. They characterized the host specificity, particle

size, heat resistance, citrate sensitivity and serological reactions of these phages. Other bacteriophages active against P. polymyxa strains were isolated later (Seldin et al., 1984; Starosciak et al., 1985; Matseliukh & Burova, 2004). They were examined by electron microscopy and their lytic spectrum was specified. These double stranded DNA phages are members of the

Siphoviridae and Myoviridae families and, similar to the phages described by Francis & Rippon (1949), they were specific only to the strains of P. polymyxa. One of the bacteriophages – designated IPy1 (Seldin et al., 1984) – was recently used for evaluation of the genetic diversity within the species P. polymyxa (dos Santos et al., 2002). Phage IPy1 DNA served as a probe in hybridization studies. In this study, the bacteriophage ΦBP active against P. polymyxa CCM 7400 is described. We characterized its host spectrum, morphology, structural protein profile, genome size and Immune system presence of the phage sequences on the bacterial host genome, and identified a cassette of lytic genes in its genome. Bacteriophage ΦBP appears to be a virulent mutant of the temperate phage and is the first such phage of P. polymyxa described in detail. Paenibacillus polymyxa CCM 7400 (Czech Collection of Microorganisms, Brno, Czech Republic) was used as the primary host for the isolation, propagation and characterization of the bacteriophage ΦBP. The isolates of P. polymyxa CCM 7400 represented clones of the same strain picked from agar plates. The following strains of the genus Paenibacillus were tested for ΦBP sensitivity: P. polymyxa S292 and P. polymyxa N36 (both from DSMZ, Germany), P. polymyxa CCM 1460, P. polymyxa CCM 1465, P. polymyxa CCM 2000, P. polymyxa CCM 2001 (all from Czech Collection of Microorganisms, Brno, Czech Republic).