title: Pseudomonas sp. BUP6, a novel isolate from Malabari goat produces an efficient rhamnolipid type biosurfactant.
abstract: This study describes the characteristics of a biosurfactant produced by Pseudomonas sp. BUP6, a rumen bacterium, and optimization of parameters required for its production. Initial screening of five parameters (pH, temperature, agitation, incubation, and substrate concentration) was carried out employing Plackett-Burman design, which reduced the number of parameters to 3 (pH, temperature, and incubation) according to their significance on the yield of biosurfactant. A suitable statistical model for the production of biosurfactant by Pseudomonas sp. BUP6 was established according to Box-Behnken design, which resulted in 11% increase (at pH 7, 35 °C, incubation 75 h) in the yield (2070 mg L-1) of biosurfactant. The biosurfactant was found stable at a wide range of pH (3-9) with 48 mg L-1critical micelle concentration; and maintained over 90% of its emulsification ability even after boiling and in presence of sodium chloride (0.5%). The highest cell hydrophobicity (37%) and emulsification (69%) indices were determined with groundnut oil and kerosene, respectively. The biosurfactant was found to inhibit the growth and adhesion of E. coli and S. aureus significantly. From the phytotoxicity studies, the biosurfactant did not show any adverse effect on the germinating seeds of rice and green gram. The structural characterization of biosurfactant employing orcinol method, thin layer chromatography and FT-IR indicated that it is a rhamnolipid (glycolipid). Thus, Pseudomonas sp. BUP6, a novel isolate from Malabari goat is demonstrated as a producer of an efficient rhamnolipid type biosurfactant suitable for application in various industries.
authors.affiliation: Enzyme Technology Laboratory, Biotechnology Division, Department of Botany, University of Calicut, Kerala, India.
authors.forename: Prakasan
authors.initials: P
authors.lastname: Priji
authors.affiliation: Enzyme Technology Laboratory, Biotechnology Division, Department of Botany, University of Calicut, Kerala, India.
authors.forename: Sreedharan
authors.initials: S
authors.lastname: Sajith
authors.affiliation: Enzyme Technology Laboratory, Biotechnology Division, Department of Botany, University of Calicut, Kerala, India.
authors.forename: Kizhakkepowathial Nair
authors.initials: KN
authors.lastname: Unni
authors.affiliation: United States Department of Agriculture, Agricultural Research Service, College Station, TX 77845, USA.
authors.forename: Robin C
authors.initials: RC
authors.lastname: Anderson
authors.affiliation: Enzyme Technology Laboratory, Biotechnology Division, Department of Botany, University of Calicut, Kerala, India.
authors.forename: Sailas
authors.initials: S
authors.lastname: Benjamin
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000302:isolation & purification / Q000494:pharmacology; D001422:Bacterial Adhesion / Q000187:drug effects; D045703:Emulsifying Agents / Q000378:metabolism; D004926:Escherichia coli / Q000187:drug effects; D006017:Glycolipids / Q000096:biosynthesis* / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D006041:Goats / Q000382:microbiology*; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D007648:Kerosene; D015233:Models, Statistical; D012275:Oryza / Q000187:drug effects / Q000254:growth & development; D000074241:Peanut Oil; D010938:Plant Oils / Q000737:chemistry; D011549:Pseudomonas / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism*; D012417:Rumen / Q000382:microbiology; D012639:Seeds / Q000187:drug effects / Q000254:growth & development; D013211:Staphylococcus aureus / Q000187:drug effects; D013501:Surface-Active Agents / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology; D013696:Temperature
chemical_list: D000900:Anti-Bacterial Agents; D045703:Emulsifying Agents; D006017:Glycolipids; D007648:Kerosene; D000074241:Peanut Oil; D010938:Plant Oils; D013501:Surface-Active Agents; C418382:rhamnolipid
keywords: Biosurfactant; Box-Behnken design; Malabari goat; Pseudomonas sp.BUP6; Rhamnolipid