1. Rapid and solitary production of mono-rhamnolipid biosurfactant and biofilm inhibiting pyocyanin by a taxonomic outlier Pseudomonas aeruginosa strain CR1
- Author
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Utkarsh Sood, Princy Hira, Mallikarjun Shakarad, Rup Lal, Vipin Chandra Kalia, Jung-Kul Lee, and Durgesh Narain Singh
- Subjects
0106 biological sciences ,0301 basic medicine ,Virulence ,Bioengineering ,Bacillus subtilis ,medicine.disease_cause ,01 natural sciences ,Applied Microbiology and Biotechnology ,Microbiology ,Surface-Active Agents ,03 medical and health sciences ,chemistry.chemical_compound ,Pyocyanin ,010608 biotechnology ,mental disorders ,medicine ,Rhizosphere ,biology ,Strain (chemistry) ,Chemistry ,Pseudomonas aeruginosa ,Biofilm ,Rhamnolipid ,General Medicine ,biology.organism_classification ,Carbon ,030104 developmental biology ,Biofilms ,Pyocyanine ,Glycolipids ,Genome, Bacterial ,Biotechnology - Abstract
Biosurfactant - Rhamnolipids (RLs) and antibacterial toxin - pyocyanin (PYO) produced by Pseudomonas aeruginosa strains have great potential for biotechnological applications. Generally, RLs are produced as a mixture of di-rhamnolipids (di-RLs) and mono-rhamnolipids (mono-RLs). Mono-RLs possess superior emulsification and antimicrobial properties and are costlier than di-RLs. In this study, a taxonomic outlier P. aeruginosa strain CR1 isolated from rhizosphere soil was explored for mono-RLs and PYO production. Phylogenetically strain CR1 resembles avirulent outlier P. aeruginosa strain ATCC9027, lacks archetypical virulence genes and harbors unique pathways for the synthesis of solely mono-RLs and PYO. Strain CR1 produced RL biosurfactant which efficiently emulsified hydrocarbons, showed hemolysis and inhibited Bacillus subtilis. At 37 °C, strain CR1 exclusively produced 21.77 g L−1 and 19.22 g L−1 rhamnolipid in glycerol amended Luria Bertani (LB) medium and basal medium amended with rice bran oil, respectively after 54 h growth. Besides RL production was unaffected under varying nitrogen sources. Structural characterization using FTIR, TLC, and LC–MS confirmed that strain CR1 exclusively produced mono-RLs, majorly dominated by Rha-C10-C10, Rha-C10-C8, and CH3-Rha-C12:2-C10:1. The compound was stable over a wide pH range (4–12), salinity (25%) and 100 °C indicating its applicability under harsh environmental conditions. In addition, strain CR1 produced 4.5 μg mL−1 PYO, which could efficiently inhibit biofilm formation by Bacillus species. The environmental outlier strain CR1 can be used for the industrial production of biotechnologically important mono-RLs and PYO.
- Published
- 2020