Transcriptomic Analysis Followed by the Isolation of Extracellular Bacteriolytic Proteases from Lysobacter capsici VKM B-2533T

Abstract

The aim of the study was to search for, isolate and characterize new bacteriolytic enzymes that show promising potential for their use in medicine, agriculture and veterinary. Using a transcriptomic analysis, we annotated in Lysobacter capsici VKM B-2533T the genes of known bacteriolytic and antifungal enzymes, as well as of antibiotics, whose expression levels increased when cultivated on media conducive to the production of antimicrobial agents. The genes of the secreted putative bacteriolytic proteases were also annotated. Two new bacteriolytic proteases, Serp and Serp3, were isolated and characterized. The maximum bacteriolytic activities of Serp and Serp3 were exhibited at low ionic strength of 10 mM Tris-HCl, and high temperatures of, respectively, 80 °C and 70 °C. The pH optimum for Serp was 8.0; for Serp3, it was slightly acidic, at 6.0. Both enzymes hydrolyzed autoclaved cells of Micrococcus luteus Ac-2230T, Proteus vulgaris H-19, Pseudomonas aeruginosa and Staphylococcus aureus 209P. Serp also digested cells of Bacillus cereus 217. Both enzymes hydrolyzed casein and azofibrin. The newly discovered enzymes are promising for developing proteolytic antimicrobial drugs on their basis.

Lysobacter gummosus 10.1.1, a Producer of Antimicrobial Agents

“…As a result of the transcriptomic analysis, almost all (eight) genes of the known bacteriolytic enzymes of Lysobacter were identified in the genome of strain 10.1.1, with the exception of the gene of bacteriolytic protease L5. These data were also compared with the earlier results of the transcriptomic analysis of L. capsici VKM B-2533 T [7] (Supplementary File S1 Table S2).…”

“…Proteases UNP29878.1 and UNP28310.1 were also identified in the culture fluid of type strain L. gummosus DSMZ 6980 [18]. Recently, we have isolated serine protease Serp (UOF16681.1) of L. capsici VKM B-2533 T , which also belongs to the S1D family, and it has been shown for the first time to be capable of hydrolyzing, in addition to protein substrates, autoclaved bacterial cells [7].…”

“…Lytic activities, however, have been shown for only five species of the genus: the species L. capsici has been added to the first four. These lytically active Lysobacter species have been shown to be capable of producing various antimicrobial compounds: antibiotics, short peptides, and bacteriolytic enzymes [2][3][4][5][6][7]. The most investigated are L. capsici and L. enzymogenes.…”

“…Isolated and characterized to varying degrees to date are bacteriolytic proteases Blp and L1 homologous to αand β-lytic proteases of L. enzymogenes; proteases L4, L5, Serp, Serp3, Serp6, and Serp7; amidase L2; and Nacetylglucosaminidase [6,7,16,17]. Our transcriptomic study of L. capsici VKM B-2533 T has revealed the significant antimicrobial potential of this species and has allowed us to find and isolate new bacteriolytic enzymes [7]. This approach has met our expectations in the search for the genes of antimicrobial agents.…”