Characterization of Autoinducer and Exopolysaccharide in Thermus spp. Biofilms
Date Issued
2005
Date
2005
Author(s)
Lin, Miao-Hsia
DOI
zh-TW
Abstract
In previous studies, bacterial species of genus Thermus living in natural hot springs are firmly attached to rocks and sands by a complex structure called biofilm. The crude biofilm exopolysaccharides (EPS) are obtained from Thermus aquaticusYT-1 plated on sterile cellophane membrane on Thermus agar plate incubation at 60 ℃ for 48 h. The crude EPS passes through TSK HW-65 gel for progressive purification and four major fractions called 231-1, 231-2, 231-3 and 231-4 with molecular weight range from 10 kDa to 500 kDa are collected. After acidic hydrolysis and derivative, the monosaccharide compositions of these four fractions are analyzed by GC-MS and HPAEC-PAD system. The results indicated that the major components of T. aquaticus YT-1 biofilm are galactose and N-acetyl galactosamine with the molar ratio of 1：1. The main glycosidic linkages are also characterized by GC-MS, showing that there are 1,3-linked Gal, 1,4-linked Gal, 1,3-linked GalNAc in 231-1, 1,4-linked Gal in 231-2, 1,4-linked Gal in 231-3 and 1,4-linked Gal, 1,3-linked GalNAc in 231-4. However, the detail structure should be further investigated.
The cultural medium of T. thermophilus HB-8 can induce to form biofilm and show to contain the autoinducer. The cultural medium is incubated overnight and collected by filtering through 10 kDa centricon. Then the filtered cultural medium is subjected to TSK-50F gel filtration chromatography for fractionation. Seven fractions are collected for bioassay. Two fractions with the smaller MW possess bioactivities to promote NTU407 biofilm formation. More studies are under preparation to elucidate their detailed structures.
Subjects
嗜熱菌
生物膜
Biofilm
Exopolysaccharide
Type
other