Structure of xanthan gum and cell ultrastructure at different times of alkali stress
Braz. j. microbiol
; Braz. j. microbiol;47(1): 102-109, Jan.-Mar. 2016. graf
Article
em En
| LILACS
| ID: lil-775115
Biblioteca responsável:
BR1.1
ABSTRACT
Abstract The effect of alkali stress on the yield, viscosity, gum structure, and cell ultrastructure of xanthan gum was evaluated at the end of fermentation process of xanthan production by Xanthomonas campestris pv. manihotis 280-95. Although greater xanthan production was observed after a 24 h-alkali stress process, a lower viscosity was observed when compared to the alkali stress-free gum, regardless of the alkali stress time. However, this outcome is not conclusive as further studies on gum purification are required to remove excess sodium, verify the efficiency loss and the consequent increase in the polymer viscosity. Alkali stress altered the structure of xanthan gum from a polygon-like shape to a star-like form. At the end of the fermentation, early structural changes in the bacterium were observed. After alkali stress, marked structural differences were observed in the cells. A more vacuolated cytoplasm and discontinuities in the membrane cells evidenced the cell lysis. Xanthan was observed in the form of concentric circles instead of agglomerates as observed prior to the alkali stress.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
LILACS
Assunto principal:
Polissacarídeos Bacterianos
/
Estresse Fisiológico
/
Xanthomonas campestris
/
Álcalis
Idioma:
En
Revista:
Braz. j. microbiol
Assunto da revista:
MICROBIOLOGIA
Ano de publicação:
2016
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Brasil