RESUMO
The objective of the present study was to evaluate the use of microbial inoculant on the chemical composition, in vitro gas production, pH, dry matter losses, aerobic stability and microbial population on silages of corn, sorghum and pearl millet in plastic bags silos (without vacuum). The experiment was carried out in a randomized block design, in a 2 × 3 factorial scheme, with and without (control) inoculant consisting of Lactobacillus plantarum and Propionibacterium acidipropionici and on three crops, corn, sorghum and pearl millet, with four replicates. The use of the inoculant did not affect the chemical composition of the silages, except the crude protein (P = 0.0062) and lignin (P = 0.0567) contents. Gas production was neither affected (P > 0.05) by the inoculant nor by the crop. Regarding aerobic stability, we observed that the inoculant affected the temperature of the sorghum silage (P = 0.0123). The inoculant decreased the N-NH3 (P =0.0095) content and increased (P = 0.0441) the lactic acid bacteria population in the silages. Thus, the microbial inoculant did not improve the fermentation profile or nutritional value of corn, pearl millet and sorghum silages in plastic bag silos (without vacuum).(AU)
O objetivo do presente estudo foi avaliar o uso de inoculante bacteriano na composição química, produção de gás in vitro, pH, perdas de matéria seca, estabilidade aeróbia e população microbiana de silagens de milho, sorgo e milheto em silos de sacos plásticos (sem vácuo). O experimento foi conduzido em delineamento de blocos casualizados, em esquema fatorial 2 × 3, [Controle] sem inoculante e Lactobacillus plantarum e Propionibacterium acidipropionici e três culturas, milho, sorgo e milheto, com quatro repetições. O uso do inoculante não afetou a composição química das silagens, exceto proteína bruta (P = 0,0062) e lignina (P = 0,0567). A produção de gás não foi afetada (P > 0,05) pelo inoculante e nem entre as culturas. Na estabilidade aeróbia, observou-se que o inoculante afetou a temperatura da silagem de sorgo (P = 0,0123). O inoculante diminuiu o conteúdo de N-NH3 (P = 0,0095). O inoculante aumentou (P = 0,0441) a população de bactérias ácido-láticas nas silagens. Assim, o inoculante microbiano não melhorou o perfil fermentativo e o valor nutricional das silagens de milho, sorgo e milheto em silos de sacos plásticos (sem vácuo).(AU)
Assuntos
Propionibacterium , Silagem , Zea mays , Pennisetum , Sorghum , Fermentação , Inoculantes Agrícolas , Milhetes , Valor Nutritivo , Técnicas In VitroRESUMO
Eight yeast isolates identified as Saccharomyces cerevisiae were recovered from molasses-using Cuban distilleries and discriminated by nucleotide sequence analysis of ITS locus. The isolates L/25-7-81 and L/25-7-86 showed the highest ethanol yield from sugarcane juice, while L/25-7-12 and L/25-7-79 showed high ethanol yield from sugarcane molasses. The isolate L/25-7-86 also displayed high fermentation capacity when molasses was diluted with vinasse. In addition, stress tolerance was evaluated on the basis of growth in the presence of inhibitors (acetic acid, lactic acid, 5-hydroxymethylfurfural and sulfuric acid) and the results indicated that L/25-7-77 and L/25-7-79 congregated the highest score for cross-tolerance and fermentation capacity. Hence, these isolates, especially L/25-7-77, could serve as potential biological platform for the arduous task of fermenting complex substrates that contain inhibitors. The use of these yeasts was discussed in the context of second-generation ethanol and the environmental and economic implications of the use of vinasse, saving the use of water for substrate dilution.