title: Biofilm inhibition and antimicrobial action of lipopeptide biosurfactant produced by heavy metal tolerant strain Bacillus cereus NK1.
abstract: Biosurfactants are worthful microbial amphiphilic molecules with efficient surface-active and biological properties applicable to several industries and processes. Among them lipopeptides represent a class of microbial surfactants with increasing scientific, therapeutic and biotechnological interests. A heavy metal tolerant Bacillus strain has been isolated and the biofilm inhibition and antimicrobial activity of biosurfactant produced by the strain have been studied. Biosurfactant production was confirmed by the conventional screening methods including hemolytic activity, drop collapsing test, oil displacement test, emulsification and lipase production assays. The biosurfactant produced by this strain was a lipopeptide and exhibited strong surface activity. The biosurfactant has been characterized using FTIR, TLC and HPLC. The minimum active dose of this biosurfactant when compared with the other chemical surfactants was found as 0.150±0.06 μg. The critical micelle concentration was found to be 45 mg/l. The biosurfactant was found to be stable and active over a wide range of pH, temperature and NaCl concentration. It was also able to emulsify a wide range of hydrocarbons and oils thereby extending its application for the bioremediation of oil contaminated sites. The biosurfactant exhibited significant reduction in biofilm formation by pathogens and showed potent antimicrobial activity against various gram positive, gram negative bacteria and fungi. Agar diffusion assay for heavy metal resistance showed that the isolate was resistant to ferrous, lead and zinc. Considering the biofilm inhibition and antimicrobial property of biosurfactant, it can be utilized as a potential therapeutic molecule for numerous microbial infections. The heavy metal resistance of the strain can also be harnessed as an invaluable biological tool for in situ bioremediation.
authors: Department of Biotechnology & Chemical Engineering, Division of Molecular and Cellular Biology, Kalasalingam University (Kalasalingam Academy of Research and Education), Anand Nagar, Krishnankoil 626126, Tamilnadu, India.
authors: Muthu Irulappan
authors: MI
authors: Sriram
authors: Kalimuthu
authors: K
authors: Kalishwaralal
authors: Venkataraman
authors: V
authors: Deepak
authors: Raja
authors: R
authors: Gracerosepat
authors: Kandasamy
authors: K
authors: Srisakthi
authors: Sangiliyandi
authors: S
authors: Gurunathan
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects; D000890:Anti-Infective Agents / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D001409:Bacillus cereus / Q000254:growth & development / Q000378:metabolism*; D001673:Biodegradation, Environmental; D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development; D002855:Chromatography, Thin Layer; D003460:Crystallization; D024881:Drug Resistance, Bacterial; D005658:Fungi / Q000187:drug effects / Q000254:growth & development; D006090:Gram-Negative Bacteria / Q000187:drug effects / Q000254:growth & development; D006094:Gram-Positive Bacteria / Q000187:drug effects / Q000254:growth & development; D006461:Hemolysis / Q000187:drug effects; D006801:Humans; D006863:Hydrogen-Ion Concentration; D055666:Lipopeptides / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D019216:Metals, Heavy / Q000378:metabolism / Q000494:pharmacology; D012965:Sodium Chloride / Q000494:pharmacology; D017550:Spectroscopy, Fourier Transform Infrared; D013501:Surface-Active Agents / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D013696:Temperature
chemical_list: D000890:Anti-Infective Agents; D055666:Lipopeptides; D019216:Metals, Heavy; D013501:Surface-Active Agents; D012965:Sodium Chloride