Effects of Dietary Cereal and Protein Source on Fiber Digestibility, Composition, and Metabolic Activity of the Intestinal Microbiota in Weaner Piglets

This study aimed to investigate the effect of fiber-rich rye and rapeseed meal (RSM) compared to wheat and soybean meal (SBM) on fiber digestibility and the composition and metabolic activity of intestinal microbiota. At weaning, 88 piglets were allocated to four feeding groups: wheat/SBM, wheat/RSM, rye/SBM, and rye/RSM. Dietary inclusion level was 48% for rye and wheat, 25% for SBM, and 30% for RSM. Piglets were euthanized after 33 days for collection of digesta and feces. Samples were analyzed for dry matter and non-starch-polysaccharide (NSP) digestibility, bacterial metabolites, and relative abundance of microbiota. Rye-based diets had higher concentrations of soluble NSP than wheat-based diets. RSM-diets were higher in insoluble NSP compared to SBM. Rye-fed piglets showed a higher colonic and fecal digestibility of NSP (p < 0.001, p = 0.001, respectively). RSM-fed piglets showed a lower colonic and fecal digestibility of NSP than SBM-fed piglets (p < 0.001). Rye increased jejunal and colonic concentration of short-chain fatty acids (SCFA) compared to wheat (p < 0.001, p = 0.016, respectively). RSM-fed pigs showed a lower jejunal concentration of SCFA (p = 0.001) than SBM-fed pigs. Relative abundance of Firmicutes was higher (p = 0.039) and of Proteobacteria lower (p = 0.002) in rye-fed pigs compared to wheat. RSM reduced Firmicutes and increased Actinobacteria (jejunum, colon, feces: p < 0.050), jejunal Proteobacteria (p = 0.019) and colonic Bacteroidetes (p = 0.014). Despite a similar composition of the colonic microbiota, the higher amount and solubility of NSP from rye resulted in an increased fermentative activity compared to wheat. The high amount of insoluble dietary fiber in RSM-based diets reduced bacterial metabolic activity and caused a shift toward insoluble fiber degrading bacteria. Further research should focus on host–microbiota interaction to improve feeding concepts with a targeted use of dietary fiber.

The Enrichment And Characterization Of Compost And Wastewater-Derived Microbial Cellulolytic Consortia For Biofuel Production

Over the last decade, a rise in energy demand and diminishing fuel resources have created a challenge for finding an alternative solution that could supplement our current energy sources. This study demonstrated that ethanol and other useful end-products can be produced from the fermentative activity of microbial consortia derived from cellulose-rich waste environments. Compost and wastewater were used as inoculum sources to enrich cellulolytic cultures at incubation temperatures 50 ºC and 60ºC. A chemically defined medium was used without complex nutrients such as yeast extract. Four cellulolytic cultures were obtained and their end-products were monitored over an active cellulose degrading period. The compost culture incubated at 50ºC produced the highest concentration of butyrate while the wastewater-derived culture incubated at 60ºC produced the highest ethanol concentration. Optimization of DNA extraction and purification from complex environmental samples such as the compost and wastewater cultures used in this study was also discussed.

The Enrichment And Characterization Of Compost And Wastewater-Derived Microbial Cellulolytic Consortia For Biofuel Production

Over the last decade, a rise in energy demand and diminishing fuel resources have created a challenge for finding an alternative solution that could supplement our current energy sources. This study demonstrated that ethanol and other useful end-products can be produced from the fermentative activity of microbial consortia derived from cellulose-rich waste environments. Compost and wastewater were used as inoculum sources to enrich cellulolytic cultures at incubation temperatures 50 ºC and 60ºC. A chemically defined medium was used without complex nutrients such as yeast extract. Four cellulolytic cultures were obtained and their end-products were monitored over an active cellulose degrading period. The compost culture incubated at 50ºC produced the highest concentration of butyrate while the wastewater-derived culture incubated at 60ºC produced the highest ethanol concentration. Optimization of DNA extraction and purification from complex environmental samples such as the compost and wastewater cultures used in this study was also discussed.

Dry biocleaning of artwork: an innovative methodology for Cultural Heritage recovery?

An innovative methodology is proposed, based on applied biotechnology to the recovery of altered stonework: the “dry biocleaning“, which envisages the use of dehydrated microbial cells without the use of free water or gel-based matrices. This methodology can be particularly useful for the recovery of highly-ornamented stoneworks, which cannot be treated using the conventional cleaning techniques. The experimental plan included initial laboratory tests on Carrara marble samples, inoculated with dehydrated Saccharomyces cerevisiae yeast cells, followed by on-site tests performed on “Quattro Fontane” (The Four Fountains), a travertine monumental complex in Rome (Italy), on altered highly ornamented areas of about 1,000 cm2. The mechanism is based on the spontaneous re-hydration process due to the environmental humidity and on the metabolic fermentative activity of the yeast cells. Evaluation by physical-chemical analyses, after 18 hours of the biocleaning, confirmed a better removal of salts and pollutants, compared to both nebulization treatment and control tests (without cells). The new proposed on-site dry biocleaning technique, adopting viable yeast cells, represents a promising method that can be further investigated and optimized for recovering specific altered Cultural Heritage stoneworks.

Influence of yeast extract enrichment on fermentative activity of Saccharomyces cerevisiae and technological properties of spelt bread

Considerable interest in the consumption of bread from ancient spelt wheat with superior nutritional properties, easy digestibility and pleasant taste and aroma, has arisen recently. Yeast extract (YE) is nowadays frequently used as natural flavor enhancer for improving organoleptic properties such as meaty, cheesy and savory attributes of different food products. YE is a natural product from baker?s yeast industry with high nutritional richness containing amino acids, peptides, nucleotides, vitamins and minerals. In this work the effect of YE, table salt and white sugar content on fermentative activity of yeast and technological properties of spelt bread was investigated by response surface methodology (RSM) aiming to define the optimal conditions for obtaining a new functional product. The addition of YE, salt and white sugar slightly decreased yeast fermentative activity, while CO2 retention in dough was found to depend more on its chemical composition. YE addition (up to 5%) was found to increase volume and decrease firmness of bread prepared from dough with sugar content up to 5%, while the opposite effect was established in bread with higher sugar content. Maximal bread elasticity was obtained for YE content of 1.57%, table salt content of 2.01% and sugar content of 7.15%.

157 The effect of sample handling methodology on ruminal redox potential measured in vivo and in vitro

Anaerobic metabolism in a biological system, such as the rumen, depends largely on the reducing power of the bacterial population present. For that reason, it is crucial to understand the relationship between redox potential (Eh) and fermentative activity. The diverse microbial profile is characterized by enzyme systems capable of maintaining a constant, yet ever-evolving rumen environment. Variation in Eh is a result of intrinsic and extrinsic factors, including measurement procedure, diet, temperature, and animal. Because Eh is sensitive to oxygen contamination, the objective of this study was to assess different procedures for post-collection rumen inoculum to determine Eh. Four hours after feeding, ten rumen fistulated steers (267.9 ± 8.4 kg), receiving a grower diet, had rumen inoculum (600 mL per animal) extracted using a vacuum suction device and Eh was measured in vivo simultaneously. One subset of samples was incubated in a 39°C water bath (Procedure 1), while the second subset of samples was placed in an ice bath (Procedure 2). Redox potential and temperature were measured at 5, 15, 30, 60, 120, and 240 minutes for both Procedures. For Procedures 1 and 2, Eh values ranged from -235.4 to -313.1 mV and -198.0 to -293.4 mV, respectively. Data were analyzed using orthogonal contrasts with animal within-day and day as random effects in the statistical model. There was no effect for Procedure × Time (P = 0.273) or Time (P = 0.396), but there were differences between Procedures (P &lt; 0.001). Polynomial contrasts indicated quadratic tendencies for Procedure 1 and the interaction of Procedure x Time (P = 0.051 and P = 0.0776, respectively). This study concluded that Procedure 2 more accurately represents in vivo Eh values, likely due to the reduced rate of fermentation associated with samples preserved on ice.

The Fermentation Process Improves the Nutritional Value of Rapeseed Cake for Turkeys—Effects on Performance, Gut Bacterial Population and Its Fermentative Activity

This experiment investigated the potential inclusion of fermented rapeseed cake (FRC) in turkey diets. The turkeys received diets either not supplemented (C) or supplemented with raw rapeseed cake (RRC) or FRC at 150 g/kg diet. In comparison with RRC, turkeys receiving FRC achieved significantly higher final BW comparable with that noted in the control group. The dietary inclusion of FRC increased the concentrations of propionic and valeric acid in the cecal digesta compared with the control group, and increased the proportion of butyric acid in SCFA profile compared with RRC group. The activities of glycolytic bacterial enzymes in the cecal digesta, were lowest in turkeys fed FRC. Experimental diets did not cause a shift in the relative abundances of the main bacterial phyla or orders in the cecal digesta. FRC increased the abundance of Bacteroidaceae at the family level, but decreased the abundance of Lactobacillus at the genus level compared with birds fed RRC. In conclusion, the dietary inclusion of FRC at 150 g/kg did not compromise bird performance, did not excessively stimulate bacterial activity, and did not cause shifts in the bacterial composition in the cecum. Actually, FCR exerted several beneficial effects that contributed to maintaining gut health in turkeys, which points to its advantage over RRC.

Assessment of Cashew Apple Juice on Fermentative Activity of Two Lactic Bacteria in Production of Yoghurt

Cashew apple is not practically used such as cashew nut which is one of most traded agricultural export products from Northern Ivory Coast. This work focus on the use of cashew apple juice as food additive in production of yoghurt. The aim of this study is to evaluate physicochemical parameters of cashew apple juice and its effect on fermentative activity of two lactic bacteria (Lactobacillus delbrueckii subsp bulgaricus and Streptococcus salivarius subsp thermophilus). Various types of yoghurt were formulated with incorporation of different proportions (0%, 5%, 10%, 15%, 25%, 35% and 40%) of cashew apple juice in milk (v/v). Each formulation was fermented with lactic ferment containing the above two lactic bacteria. Effect of juice on fermentative activity of the two bacteria was carried out by pH, titratable acidity with duration of fermentation to obtain 80 Dornic degrees. Results of phytochemical analysis (p<0.05) showed that cashew apple juice have an acid pH with value of 3.96 ± 0.03 and titratable acidity of 0.41 ± 0.01%. This juice contains a high level of moisture (77.48 ± 0.09%) and vitamin C (124.74 ± 1.17 mg/100ml) but a low concentration of reducing sugars (1.46 ± 0.03 g/100ml). The study of effect of cashew apple juice incorporated into milk, showed that the formulations with 5% and 10% improved fermentative activity of lactic bacteria tested. These two formulations (5% and 10%) reduced fermentation time (180 min) compared to control (220 min). This study suggests that cashew apple juice could be a food additive in production of yoghurts as a source of vitamin C and catalyst for fermentation. In perspective, we plan to assess toxicity and shelf of yoghurt with cashew apple juice.