Tropical Journal of Pharmaceutical Research

Original Research Article | OPEN ACCESS

Determination of levan from Bacillus licheniformis by ultraviolet spectrophotometry

Wenbo Zhang¹ , Xiuhua Zhang¹, Lulu Cai¹, Ruifeng Chen¹, Qilai Zhang², Xiang Wang³

¹School of Life Sciences and Technology, Xinxiang Medical University, Xinxiang 453003, Henan; ²Environmental Protection Bureau of Wuqing District; ³College of Environmental and Chemical Engineering, Tianjin Polytech University, Tianjin 300387, China.

For correspondence:- Wenbo Zhang Email: zhangwenbo@xxmu.edu.cn Tel:+86373383192

Received: 18 December 2014 Accepted: 22 March 2015 Published: 26 April 2015

Citation: Zhang W, Zhang X, Cai L, Chen R, Zhang Q, Wang X. Determination of levan from Bacillus licheniformis by ultraviolet spectrophotometry. Trop J Pharm Res 2015; 14(4):679-685 doi: 10.4314/tjpr.v14i4.17

© 2015 The authors.
This is an Open Access article that uses a funding model which does not charge readers or their institutions for access and distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0) and the Budapest Open Access Initiative (http://www.budapestopenaccessinitiative.org/read), which permit unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited..

Abstract

Purpose: To establish a first-order derivative ultraviolet spectrophotometric (FODUS) method with good reproducibility for the determination of levan, a D-fructofuranosyl polymer with a β-(2-6) backbone and β-(2-1) branching.

Methods: Levan was isolated from fermentation broth by alcohol precipitation and ultrafiltration. Factors influencing the determination of the ultraviolet (UV) spectrophotometric method was compared with a single-factor analysis. The UV spectra of levan reaction solutions in the absorbance range of 200 - 400 nm were obtained. An orthogonal experimental design was applied to optimize the sulfuric acid hydrolysis conditions in the spectrophotometric determination. FODUS method was validated by analyzing its linearity, reproducibility, stability and recovery.

Results: Factors influencing absorbance for the determination were confirmed and two regression equations were established. UV absorbance at 320 nm of sulfuric acid-hydrolyzed sample was stable for 5 h. The FODUS method developed had a good reproducibility (RSD = 2.1 %, n = 5), linearity (ranging from 1.6 μg/mL to 12.8 μg/mL), R² = 0.9996) and recovery (95.90 %, RSD = 1.7 %, n = 3).

Conclusion: The developed FODUS method is convenient, efficient and robust for the determination of microbial levan. The method provides a valuable approach for the determination of polysaccharides.

Keywords: Derivative spectrophotometry, Bacillus licheniformis, Levan, Total carbohydrate determination