Lytic Peptidase L5 of <b><i>Lysobacter </i></b>sp. XL1 with Broad Antimicrobial Spectrum

Abstract

The Gram-negative bacterium Lysobacter sp. XL1 secretes lytic enzymes (L1-L5) into the culture medium. Enzyme L5 is the most recently found extracellular lytic enzyme of this bacterium. The paper presents the results of the isolation and characterization of some properties of this enzyme. Thus, enzyme L5 of Lysobacter sp. XL1 is a lytic serine protease. Earlier, the enzyme was shown to be secreted into the culture medium by means of outer membrane vesicles, which possess a lytic effect towards living cells of Erwinia caratovora B15 [Vasilyeva et al., FEBS J 2008;15:3827-3835]. This work shows the action of enzyme L5 either as a vesicle component or the homogeneous enzyme L5 on a broad range of Gram-positive and Gram-negative microorganisms. Moreover, the vesicles containing this enzyme were shown to lyze the selected test cultures more efficiently than the soluble enzyme L5. It appears to be one of the first precedents of a bacteriolytic effect mediated by the action of outer membrane vesicles filled with extracellular lytic enzymes. The results suggest that the enzyme L5 of Lysobacter sp. XL1 and the vesicles containing this enzyme can be used as an antimicrobial drug.

The impact of the omics era on the knowledge and use ofLysobacterspecies to control phytopathogenic micro-organisms

“…As regards the control of phytopathogenic micro‐organisms, these enzymes may be exploited for the control of phytopathogenic bacteria such as Erwinia carotovora (Vasilyeva et al . ), and nematodes such as a nematicidal enzyme belonging to the group of metallopeptidases produced by L. capsici YS1215, which is active against the second‐stage juveniles of M. incognita (Table ; Lee et al . ).…”

“…Proteolytic activity is one of the characteristics shared by Lysobacter members that has received most attention, because of its possible application to research and industrial processes (G€ okc ßen et al 2014). As regards the control of phytopathogenic micro-organisms, these enzymes may be exploited for the control of phytopathogenic bacteria such as Erwinia carotovora (Vasilyeva et al 2014), and nematodes such as a nematicidal enzyme belonging to the group of metallopeptidases produced by L. capsici YS1215, which is active against the second-stage juveniles of M. incognita (Table 2; Lee et al 2013).…”

Gene Expression of Lytic Endopeptidases AlpA and AlpB from <b><i>Lysobacter </i></b>sp. XL1 in Pseudomonads

“…The biochemical properties of the produced recombinant proteins AlpA and AlpВ, such as temperature and pH optima, half-inactivation temperature and effect of inhibitors, were similar to the corresponding proteins from Lysobacter sp. XL1 [Stepnaya et al, 1996a;Vasilyeva et al, 2014]. The optimal conditions for hydrolysis of autoclaved S. aureus 209P cells by the recombinant enzymes AlpA and AlpB were, respectively: a pH value of 7-11 and 7.5, Tris-HCl 50 and 10 m M , and an optimum reaction temperature of 70 and 80°С.…”

“…XL1 secretes five lytic enzymes into the culture liquid, namely three endopeptidases L1, L4 and L5, muramyl-alanine amidase L2 and muramidase L3 [Stepnaya et al, 1986[Stepnaya et al, , 1996a[Stepnaya et al, , b, 2005Vasilyeva et al, 2008Vasilyeva et al, , 2014. The medicinal agent lysoamidase based on the culture liquid of this bacterium possesses a broad range of antimicrobial action with respect to Gram-positive and Gram-negative bacteria, yeasts, fungi and protozoa.…”

“…The antimicrobial range of AlpB expands significantly for its vesicular form. Thus, for instance, in contrast to its soluble form, vesicular AlpB destroys native cells of Peptostreptococcus carotovorum and S. aureus [Vasilyeva et al, 2008[Vasilyeva et al, , 2014.…”