Data/hora: 12/06/2024 04:44:55

Biblioteca(s): | Embrapa Pecuária Sudeste.
Data corrente: | 15/03/2010
Data da última atualização: | 20/07/2011
Autoria: | ADESOGAN, A. T.; PEDROSO, A. de F.; QUEIROZ, O. C. M.; WILLIAMS, S. K.
Afiliação: | A. T. ADESOGAN, UNIVERSITY OF FLORIDA/GAINSVILLE; ANDRE DE FARIA PEDROSO, CPPSE; O. C. M. QUEIROZ, UNIVERSITY OF FLORIDA/GAINSVILLE; S. K. WILLIAMS, UNIVERSITY OF FLORIDA/GAINSVILLE.
Título: | Using bacterial inoculants to control the growth of E. coli O157:H7 in maize silages under anaerobic and aerobic conditions.
Ano de publicação: | 2009
Fonte/Imprenta: | In: FAO/IAEA SYMPOSIUM ON SUSTAINABLE IMPROVEMENT OF ANIMAL PRODUCTION AND HEALTH, 2009, Vienna. Proceedings... Vienna: FAO/IAEA, 2009.
Idioma: | Português
Conteúdo: | The aim was to determine if bacterial inoculants could eliminate E. coli O157:H7 (ECOL) in contaminated corn silages and if inoculants transferred antibacterial activity to silages. Chopped corn forage was ensiled in triplicate after treatment with:1) distilled water (control); 2) 5 x 105 cfu/g of ECOL (EC); 3) EC and 1 x 106 cfu/g of Pediococcus pentosaceus and Propionibacterium freudenreichii (EC+BII); 4) EC and 1 x 106 cfu/g of Lactobacillus buchneri (LB; EC+LB); 5) EC and 1 x 106 cfu/g of LB and P. pentosaceus (EC+B500). Silos were opened after 3, 7, 31, and 82 d and analyzed for pH and ECOL counts as well as VFA, lactate, and aerobic stability on d 82. By d 3, all silages had pH was <4 (SE=0.33; p=1) and pH did not increase subsequently; therefore ECOL was not detected in any silage. The Kirby-Bauer disc diffusion test showed that all pure cultures of inoculants had pH-independent antibacterial activity against ECOL but inoculated silages did not, suggesting that ECOL elimination was mediated by pH reduction. Inoculation with LB resulted in less lactate (SE=0.31; p<0.05), more acetate (SE=0.35; p<0.05), and greater aerobic stability (SE=7.1; p<0.05) versus control. Day-82 silages were reinoculated with EC at silo opening (immediate) or after 144 h of exposure (delay) and ECOL were enumerated 24 h later. All immediately reinoculated silages had low pH values (<4) and no ECOL 24 h later. Control, EC, and EC+BII silages reinoculated after the delay had relatively high pH values (4.71, 5.67, and 6.03) (SE=0.74; p<0.05) and ECOL counts (2.87, 6.73, and 6.87 log cfu/g) (SE=1.4; p<0.05), whereas those treated with LB had low pH values (<4) and undetectable (EC+B500) or low ECOL counts (1.96, cfu/g; EC+LB). Inoculants did not enhance elimination of ECOL during ensiling, but L. buchneri inoculants increased stability and eliminated or inhibited ECOL in aerobically exposed silages.
Palavras-Chave: | Antibacterial activity; E. coli; Inoculant; Maize silage.
Categoria do assunto: | --
URL: | http://ainfo.cnptia.embrapa.br/digital/bitstream/item/38056/1/PROCI-2009.00383.pdf
Registro original: | Embrapa Pecuária Sudeste (CPPSE)
Exemplares: | CPPSE - (19109-1) - UPC - RA - PP - PROCI-2009.00383 - ADE - 2009.00383 - DIS