Short-chain fatty acids production by Bifidobacterium species in the presence of salep

BACKGROUND: Salep is obtained by grinding dried orchid tubers and used as a valuable ingredient in the food industry. Because of the glucomannan content of salep, it is thought to have prebiotic potential. However, there is little information in studies concerning the fermentation characteristics and potential prebiotic properties of salep. The objective of this study was to investigate the effect of salep on bifidobacterial growth by measuring the highest optical density (OD), calculating the specific growth rates, and determining the production of lactic acid and short-chain fatty acids (acetic, propionic, and butyric acid) as a result of bacterial fermentation. RESULT: The OD and pH values obtained in this study showed that salep was utilized as a source of assimilable carbon and energy by the Bifidobacterium species (BS). All Bifidobacterium strains produced lactic, acetic, propionic, and butyric acid, indicating that salep is readily fermented by these bacteria. Salep at 1% (w/v) showed a similar effect on bifidobacterial growth as that promoted by 1% (w/v) glucose used as a traditional carbon source. CONCLUSIONS: Bifidobacterium species can develop in media containing salep as well as in glucose and exhibit the potential to be used as new sources of prebiotics.

Production of Propionic Acid by Propionibacterium acidipropionici from Agroindustrial Effluents

Abstract The purpose of this paper was to evaluate the production of propionic acid from the fermentation of agroindustrial effluents using a Propionibacterium acidipropionici culture. The composition of the substrates was determined by using an experimental design of mixtures, resulting in 10 trials. The substrates were fermented in batch borosilicate glass reactors at a temperature of 35°C, initial pH of 6.5, and 20 mL.L-1 of inoculum suspension. The highest yield of propionic acid production, 0.79 g of product per g of substrate, was obtained with a substrate composed only of corn steep liquor, which showed a productivity of 5.20 mg.L-1h-1 and production of 0.40mL.L-1. These results showed that the corn steep liquor positively influenced performance and productivity. Although the production of acid did not reach high values, the results indicate that it is possible to produce propionic acid by a biotechnological route; however, further studies are required to adapt and optimise these results.

Effects of volatile fatty acids in biohydrogen effluent on biohythane production from palm oil mill effluent under thermophilic condition

Background: Biohydrogen effluent contains a high concentration of volatile fatty acid (VFA) mainly as butyric, acetic, lactic and propionic acids. The presence of various VFAs (mixture VFAs) and their cooperative effects on two-stage biohythane production need to be further studied. The effect of VFA concentrations in biohydrogen effluent of palm oil mill effluent (POME) on methane yield in methane stage of biohythane production was investigated. Results: The methane yield obtained in low VFA loading (0.9 and 1.8 g/L) was 15­20% times greater than that of high VFA loading (3.6 and 4.7 g/L). Butyric acid at high concentrations (8 g/L) has the individual significantly negative effect the methane production process (P b 0.05). Lactic, acetic and butyric acid mixed with propionic acid at a concentration higher than 0.5 g/L has an interaction significantly negative effect on the methanogenesis process (P b 0.05). Inhibition condition had a negative effect on both bacteria and archaea with inhibited on Geobacillus sp., Thermoanaerobacterium thermosaccharolyticum, Methanoculleus thermophilus and Methanothermobacter delfuvii resulting in low methane yield. Conclusion: Preventing the high concentration of butyric acid, and propionic acid in the hydrogenic effluent could enhance methane production in two-stage anaerobic digestion for biohythane production.

Sintese de novos derivados do acido 3-fosfonopropionico / Synthesis of new derivatives of 3-phosphonopropionic acid

Foram sintetizadas tres series de derivados do acido 3-fosfonopropionico, compreendendo 22 substancias, das quais 16 ainda nao descritas na literatura. Todas as substancias foram caracterizadas por analise elementar, espectroscopia no infravermelho e espetrometria de ressonacia magnetica protonica. Os compostos obtidos foram encaminhados para ensaios experimentais na doenca de Chagas