Data/hora: 12/06/2024 14:35:13

Provedor de dados: 	58	
País: 	Brazil	
Título: 	Structure of xanthan gum and cell ultrastructure at different times of alkali stress	
Autores: 	Luvielmo,Márcia de Mello; Borges,Caroline Dellinghausen; Toyama,Daniela de Oliveira; Vendruscolo,Claire Tondo; Scamparini,Adilma Regina Pippa.	
Data: 	2016-03-01	
Ano: 	2016	
Palavras-chave: 	Xanthomonas campestris; Xanthan production; Alkali stress; Transmission microscopy; Scanning electron microscopy.	
Resumo: 	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.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822016000100102	
Editor: 	Sociedade Brasileira de Microbiologia	
Relação: 	10.1016/j.bjm.2015.11.006	
Formato: 	text/html	
Fonte: 	Brazilian Journal of Microbiology  v.47 n.1 2016	
Fonte: 	info:eu-repo/semantics/openAccess