Data/hora: 07/06/2024 09:24:12

Biblioteca(s): | Embrapa Agrobiologia.
Data corrente: | 01/12/1997
Data da última atualização: | 01/12/1997
Autoria: | RIBEIRO, J. R. A.; OLIVEIRA, A. L. B.; RUMJANEK, V.; RUMJANEK, N. G.
Título: | Polysaccharides production by Bradyrhizobium japonicum.
Ano de publicação: | 1996
Fonte/Imprenta: | In: REUNIAO ANUAL DA SOCIEDADE BRASILEIRA DE BIOQUIMICA E BIOLOGIA MOLECULAR, 25., maio 1996, Caxambu. Resumos... Caxambu: Sociedade Brasileira de Bioquimica e Biologia Molecular, 1996. p.115. Resumo L-54.
Idioma: | Inglês
Conteúdo: | Rhizobia are symbiotic nitrogen fixing bacteria which infect the roots of leguminous plants. Bacterial competition, infection of the plant by the bacteria, nodule formation and fixation efficiency are processes that dependent heavily on the intense exchange of molecular signals between symbionts. Rhizobia are gram-negative bacteria which have, no their surface, a high amount of polysaccharides believed to play a major part on the above processes. The more important sugars are the exopolysaccharides (EPS), capsular polysaccharides (CPS) and lipopolysaccharides (LPS). Many studies have been carried out to determine the functions of these polysaccharides in the rhizobium-legume symbiosis. Although these investigations employ structural determination and gene mapping, there has been no attempt to correlate polysaccharide production with culture growth time in cultures of B. japonicum BR-23. EPS were isolated from the cultures from the 2nd to the 3th day of growth and purified. They were submitted to SDS-Page and stained with silver nitrate. The gels were also stained with Coomassive blue and showed no protein present. The electrophoresis profiles of the EPS at each day of bacterial growth are markedly different, especially the ones relative to the last 2 days as compared to the first days of growth. At the beginning bands at 60, 43, 40, 28, 25, 19 and 15 kDe are present whereas at the end of the 8 day period, the gel shows bands at 55, 40, 38, 24 and 19 kDe. Furthermore, there is a tendency of the early extracts to contain EPS with lower molecular weights than the ones found in the extracts at the end of culture growth.
Palavras-Chave: | Production.
Thesagro: | Polissacarídeo; Produção; Rhizobium Japonicum.
Thesaurus Nal: | polysaccharides.
Categoria do assunto: | --
Registro original: | Embrapa Agrobiologia (CNPAB)
Exemplares: | CNPAB - (24349-1) - UPC - PL - -- -  -  - 22190 - DIS