Data/hora: 06/06/2024 00:23:38

Provedor de dados: | 45
País: | Brazil
Título: | In vitro effect of pH on resistance of ruminal bacteria to intracellular potassium depletion, and effect of pH and ionophores on ammonia and microbial protein production
Autores: | Leopoldino,W.M.; Lana,R.P.; Borges,A.C.; Mantovani,H.C.; Teixeira,R.M.A.; Oliveira,J.S.; Jaremtchuk,A.R.; Eifert,E.C.; Martins,R.G.R.
Data: | 2005-12-01
Ano: | 2005
Palavras-chave: | Bacteria; Lasalocid; Monensin; PH; Rumen.
Resumo: | Ruminal fluid from steers fed on pasture was incubated with artificial media at pH 5.5 and 7.0 in two experiments. In the first, the effect of monensin level on resistance of ruminal bacteria to potassium depletion was evaluated; in the second, effects of the ionophores monensin and lasalocid on ammonia and protein production were quantified. In experiment 1, culture media affected potassium level. The monensin concentration needed to cause half maximal potassium depletion was 2.77µM at pH 5.5 but was 0.056µM at pH 7.0, showing that bacteria incubated at pH 5.5 were more tolerant to monensin than those incubated at pH 7.0. Both ionophores as well as increased acidity caused decreased ammonia production. Both ionophores inhibited ammonia production by 56%, independently of pH. In cultures incubated at pH 5.5 compared to pH 7.0, ammonia production was decreased by 50.5%, independently of the ionophores. Therefore, effects of ionophores and acidity were additive, and the maximum inhibition occurred in the presence of an ionophore at low pH (75.2%). Microbial protein production was lowest when lasalocid was present in a low pH culture medium, causing inhibition of microbial growth.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-09352005000600012
Editor: | Universidade Federal de Minas Gerais, Escola de Veterinária
Relação: | 10.1590/S0102-09352005000600012
Formato: | text/html
Fonte: | Arquivo Brasileiro de Medicina Veterinária e Zootecnia  v.57 n.6 2005
Fonte: | info:eu-repo/semantics/openAccess