RESUMO
Lactobacillus reuteri LPB P01-001 was isolated from the gastrointestinal tract of wild swine and was characterised by biochemical testing and sequencing of gene 16S rRNA. A simple and low-cost culture medium based on cane sugar (2.5% p/v) and yeast extract (1% p/v) was used in the production of this probiotic. The fermentative conditions were a) pH control at 6.5 and b) no pH control; both were set at 37°C in a 12 L slightly stirred tank bioreactor. Fermentation parameters such as the specific growth rate, productivity and yield of biomass, lactic and acetic acid levels were determined. L. reuteri LPB P01-001 behaves as an aciduric bacteria because it grows better in a low pH medium without pH control. However, the lactic acid production yield was practically half (9.22 g.L-1) of that obtained under a constant pH of 6.5, which reached 30.5 g.L-1 after 28 hours of fermentation. The acetic acid production was also higher under pH-controlled fermentation, reaching 10.09 g.L-1 after 28 hours of fermentation. These parameters may raise the interest of those committed to the efficient production of a probiotic agent for swine.
Assuntos
Ácido Láctico/análise , Ácido Láctico/metabolismo , Crescimento Bacteriano , Biomassa , Reatores Biológicos , Trato Gastrointestinal , Limosilactobacillus reuteri/isolamento & purificação , Limosilactobacillus reuteri/metabolismo , Probióticos , Métodos , Padrões de Referência , Suínos , MétodosRESUMO
Lactobacillus reuteri LPB P01-001 was isolated from the gastrointestinal tract of wild swine and was characterised by biochemical testing and sequencing of gene 16S rRNA. A simple and low-cost culture medium based on cane sugar (2.5% p/v) and yeast extract (1% p/v) was used in the production of this probiotic. The fermentative conditions were a) pH control at 6.5 and b) no pH control; both were set at 37°C in a 12 L slightly stirred tank bioreactor. Fermentation parameters such as the specific growth rate, productivity and yield of biomass, lactic and acetic acid levels were determined. L. reuteri LPB P01-001 behaves as an aciduric bacteria because it grows better in a low pH medium without pH control. However, the lactic acid production yield was practically half (9.22 g.L(-1)) of that obtained under a constant pH of 6.5, which reached 30.5 g.L(-1) after 28 hours of fermentation. The acetic acid production was also higher under pH-controlled fermentation, reaching 10.09 g.L(-1)after 28 hours of fermentation. These parameters may raise the interest of those committed to the efficient production of a probiotic agent for swine.
RESUMO
The aim of this work was to develop an economical bioprocess to produce the bio-ethanol from soybean molasses at laboratory, pilot and industrial scales. A strain of Saccharomyces cerevisiae (LPB-SC) was selected and fermentation conditions were defined at the laboratory scale, which included the medium with soluble solids concentration of 30% (w/v), without pH adjustment or supplementation with the mineral sources. The kinetic parameters - ethanol productivity of 8.08g/Lh, YP/S 45.4%, YX/S 0.815%, m 0.27h(-1) and microX 0.0189h(-1) - were determined in a bench scale bioreactor. Ethanol production yields after the scale-up were satisfactory, with small decreases from 169.8L at the laboratory scale to 163.6 and 162.7L of absolute ethanol per ton of dry molasses, obtained at pilot and industrial scales, respectively.
Assuntos
Etanol/metabolismo , Glycine max/metabolismo , Microbiologia Industrial , Laboratórios , Melaço , Saccharomyces cerevisiae/metabolismo , Antiespumantes/farmacologia , Biomassa , Reatores Biológicos , Carboidratos , Meios de Cultura , Fermentação/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Cinética , Projetos Piloto , Saccharomyces cerevisiae/efeitos dos fármacos , Solubilidade/efeitos dos fármacos , Glycine max/efeitos dos fármacosRESUMO
Studies were carried out in a packed-bed column fermentor using coffee husk as substrate in order to verify a relationship between caffeine degradation and the respiration of Aspergillus sp. LPBx. Fermentation conditions were optimized by using factorial design experiments. The kinetic study showed that the caffeine degradation was related to the development of mold and its respiration and also with the consumption of reducing sugars present in coffee husk. From the values obtained experimentally for oxygen uptake rate and CO2 evolved, we determined a biomass yield of 3.811 g of biomass/g of consumed O2 and a maintenance coefficient of 0.0031 g of consumed O2/(g of biomass x h). The maximum caffeine degradation achieved was 90%.