fulltext.study @t Gmail

Effective stimulating factors for microbial levan production by Halomonas smyrnensis AAD6T

Paper ID Volume ID Publish Year Pages File Format Full-Text
20235 43164 2015 9 PDF Available
Title
Effective stimulating factors for microbial levan production by Halomonas smyrnensis AAD6T
Abstract

Levan is a bioactive fructan polymer that is mainly associated with high-value applications where exceptionally high purity requirements call for well-defined cultivation conditions. In this study, microbial levan production by the halophilic extremophile Halomonas smyrnensis AAD6T was investigated systematically. For this, different feeding strategies in fed-batch cultures were employed and fermentation profiles of both shaking and bioreactor cultures were analyzed. Initial carbon and nitrogen source concentrations, production pH, NaCl and nitrogen pulses, nitrogen and phosphorous limitations, trace elements and thiamine contents of the basal production medium were found to affect the levan yields at different extends. Boric acid was found to be the most effective stimulator of levan production by increasing the sucrose utilization three-fold and levan production up to five-fold. This significant improvement implied the important role of quorum sensing phenomenon and its regulatory impact on levan production mechanism. Levan produced by bioreactor cultures under conditions optimized within this study was found to retain its chemical structure. Moreover, its biocompatibility was assessed for a broad concentration range. Hence H. smyrnensis AAD6T has been firmly established as an industrially important resource microorganism for high-quality levan production.

Keywords
Levan; Fructan; Halomonas smyrnensis; Exopolysaccharides; Boric acid; Quorum sensing
First Page Preview
Effective stimulating factors for microbial levan production by Halomonas smyrnensis AAD6T
Publisher
Database: Elsevier - ScienceDirect
Journal: Journal of Bioscience and Bioengineering - Volume 119, Issue 4, April 2015, Pages 455–463
Authors
, , , , ,
Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering