Disruption of microbial biofilms by an extracellular protein isolated from epibiotic tropical marine strain of Bacillus licheniformis

• Published in: PloS one Vol. 8; no. 5; p. e64501
• Main Authors: Dusane, Devendra H, Damare, Samir R, Nancharaiah, Yarlagadda V, Ramaiah, N, Venugopalan, Vayalam P, Kumar, Ameeta Ravi, Zinjarde, Smita S
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 15.05.2013; Public Library of Science (PLoS)
• Subjects: Analysis; Antibiotics; Antiinfectives and antibacterials; Antimicrobial activity; Antimicrobial agents; Bacillus; Bacillus - metabolism; Bacillus - pathogenicity; Bacillus licheniformis; Bacillus pumilus; Bacteria; Bacterial Proteins - isolation & purification; Bacterial Proteins - physiology; Bioactive compounds; Biofilms; Biofouling; Bioinformatics; Biology; Biotechnology; Candida albicans; Chromatography; Chromatography, Gel; Earth Sciences; Electrophoresis, Polyacrylamide Gel; Endopeptidase K; Food processing industry; Gel electrophoresis; Genomes; Homology; Ionization; Laboratories; Laboratory equipment; Marine Biology; Microbial Sensitivity Tests; Microorganisms; Microscopy, Electron, Scanning; Minimum inhibitory concentration; Natural products; Nucleotide sequence; Oceanography; Peptides; pH effects; Polystyrene; Polystyrene resins; Proteinase; Proteins; Pseudomonas aeruginosa; Sodium; Sodium dodecyl sulfate; Sodium lauryl sulfate; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Sulfates; Surface active agents; Trypsin; Ultrafiltration; United States > US
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0064501

Marine epibiotic bacteria produce bioactive compounds effective against microbial biofilms. The study examines antibiofilm ability of a protein obtained from a tropical marine strain of Bacillus licheniformis D1. B. licheniformis strain D1 isolated from the surface of green mussel, Perna viridis showed antimicrobial activity against pathogenic Candida albicans BH, Pseudomonas aeruginosa PAO1 and biofouling Bacillus pumilus TiO1 cultures. The antimicrobial activity was lost after treatment with trypsin and proteinase K. The protein was purified by ultrafiltration and size-exclusion chromatography. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and matrix assisted laser desorption/ionization-time of flight (MALDI-TOF) analysis revealed the antimicrobial agent to be a 14 kDa protein designated as BL-DZ1. The protein was stable at 75°C for 30 min and over a pH range of 3.0 to 11.0. The sequence alignment of the MALDI-fingerprint showed homology with the NCBI entry for a hypothetical protein (BL00275) derived from B. licheniformis ATCC 14580 with the accession number gi52082584. The protein showed minimum inhibitory concentration (MIC) value of 1.6 µg/ml against C. albicans. Against both P. aeruginosa and B. pumilus the MIC was 3.12 µg/ml. The protein inhibited microbial growth, decreased biofilm formation and dispersed pre-formed biofilms of the representative cultures in polystyrene microtiter plates and on glass surfaces. We isolated a protein from a tropical marine strain of B. licheniformis, assigned a function to the hypothetical protein entry in the NCBI database and described its application as a potential antibiofilm agent.