Emulsifying Activities of Purified Alasan Proteins from Acinetobacter radioresistens KA53
- 1 March 2001
- journal article
- Published by American Society for Microbiology in Applied and Environmental Microbiology
- Vol. 67 (3), 1102-1106
- https://doi.org/10.1128/aem.67.3.1102-1106.2001
Abstract
The bioemulsifier of Acinetobacter radioresistens KA53, referred to as alasan, is a high-molecular-weight complex of polysaccharide and protein. The emulsifying activity of the purified polysaccharide (apo-alasan) is very low. Three of the alasan proteins were purified by preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis and had apparent molecular masses of 16, 31, and 45 kDa. Emulsification assays using the isolated alasan proteins demonstrated that the active components of the alasan complex are the proteins. The 45-kDa protein had the highest specific emulsifying activity, 11% higher than the intact alasan complex. The 16- and 31-kDa proteins gave relatively low emulsifying activities, but they were significantly higher than that of apo-alasan. The addition of the purified 16- and 31-kDa proteins to the 45-kDa protein resulted in a 1.8-fold increase in the specific emulsifying activity and increased stability of the oil-in-water emulsion. Fast-performance liquid chromatography analysis indicated that the 45-kDa protein forms a dimer in nondenaturing conditions and interacts with the 16- and 31-kDa proteins to form a high-molecular-mass complex. The 45-kDa protein and the three-protein complex had substrate specificities for emulsification and a range of pH activities similar to that of alasan. The fact that the purified proteins are active emulsifiers should simplify structure-function studies and advance our understanding of their biological roles.Keywords
This publication has 23 references indexed in Scilit:
- An OmpA-Like Protein fromAcinetobacterspp. Stimulates Gastrin and Interleukin-8 PromotersInfection and Immunity, 2000
- Surface Active Polymers from the Genus AcinetobacterPublished by Springer Science and Business Media LLC ,1998
- Emulsifier production and microscopical study of emulsions and biofilms formed by the hydrocarbon-utilizing bacteria Acinetobacter calcoaceticus MM5Applied Microbiology and Biotechnology, 1996
- Biosurfactants production and possible uses in microbial enhanced oil recovery and oil pollution remediation: A reviewBioresource Technology, 1995
- Novel bioemulsifiers from microorganisms for use in foodsJournal of Biotechnology, 1995
- EFFECT OF PROTEIN ON THE EMULSIFYING ACTIVITY OF EMULSANJournal of Dispersion Science and Technology, 1989
- The surface activity of Acinetobacter calcoaceticus sp. 2CA2Biotechnology & Bioengineering, 1984
- Emulsifier production byAcinetobacter calcoaceticus strainsCurrent Microbiology, 1983
- Emulsifier of Arthrobacter RAG‐1: determination of emulsifier‐bound fatty acidsFEBS Letters, 1979
- Cleavage of Structural Proteins during the Assembly of the Head of Bacteriophage T4Nature, 1970