Elevation of volatile fatty acid levels and adjustment of acetate/propionate ratios during ruminal fermentation of various feedstuffs with the high strength yeast culture, Yea-Sacc1026

1991 ◽  
Vol 19 (1) ◽  
pp. 72S-72S
Author(s):  
J. PHILIP RYAN ◽  
WILLIAM R. GRAY
Keyword(s):  
Fatty Acid ◽  
Volatile Fatty Acid ◽  
High Strength ◽  
Yeast Culture ◽  
Ruminal Fermentation

Microbial electrochemical sensors for volatile fatty acid measurement in high strength wastewaters: A review

2020 ◽  
Vol 165 ◽  
pp. 112409 ◽  
Author(s):  
Andrew Hill ◽  
Stephan Tait ◽  
Craig Baillie ◽  
Bernardino Virdis ◽  
Bernadette McCabe
Keyword(s):  
Fatty Acid ◽  
Volatile Fatty Acid ◽  
Electrochemical Sensors ◽  
High Strength

Influence of zeolite (clinoptilolite) supplementation on characteristics of digestion and ruminal fermentation of steers fed a steam-flaked corn-based finishing diet

2018 ◽  
Vol 58 (7) ◽  
pp. 1239
Author(s):  
J. D. Urías-Estrada ◽  
M. A. López-Soto ◽  
A. Barreras ◽  
J. A. Aguilar-Hernández ◽  
V. M. González-Vizcarra ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Volatile Fatty Acid ◽  
Positive Impact ◽  
Latin Square ◽  
Basal Diet ◽  
Ruminal Fermentation ◽  
Faecal Excretion ◽  
Linear Effect ◽  
Molar Proportion ◽  
Volatile Fatty Acid Concentration

Four Holstein steers (328 ± 14 kg) with ruminal and duodenal cannulas were used in a 4 × 4 Latin square design to examine the effect of level of zeolite supplementation (0, 10, 20 or 30 g clinoptilolite-Ca/kg of diet) in a steam-flaked corn-based finishing diet on the characteristics of ruminal fermentation and nutrient digestion. Zeolite was top-dressed with the basal diet at time of feeding; therefore, intake of organic matter (OM), neutral detergent fibre (NDF), starch and N was equal in all treatments. Zeolite supplementation did not affect site and extent of digestion of N or NDF. Zeolite linearly decreased (P < 0.01) NH3-N flow to duodenum, but did not affect duodenal flow of microbial N, feed N, or microbial efficiency. Inclusion of zeolite linearly increased (P = 0.02) ruminal OM digestion and tended (linear, P = 0.08) to increase ruminal digestion of starch. Zeolite supplementation increased (linear effect, P < 0.01) faecal excretion of ash, resulting in decreased total tract DM digestion (linear effect, P = 0.04). However, total tract digestion of OM tended to increase (P = 0.06) with increasing zeolite supplementation. Thus, dilution of the diet with zeolite did not depress dietary digestible energy. There were no treatment effects on ruminal pH. Total ruminal volatile fatty acid concentration tended (P = 0.08) to increase as zeolite increased. Zeolite supplementation decreased ruminal molar proportion of acetate and increased molar proportion of propionate (linear effect, P < 0.01), resulting in decreased (linear effect, P < 0.01) of acetate: propionate ratio. Supplementation with zeolite at levels of up to 30 g of zeolite/kg of diet may enhance ruminal OM digestion, largely due to the tendency of increased ruminal starch digestion. Zeolite supplementation altered ruminal volatile fatty acid molar proportions (decreased acetate : propionate ratio), and therefore may have an positive impact on energy efficiency.

pH-adjustment strategy for volatile fatty acid production from high-strength wastewater for biological nutrient removal

2014 ◽  
Vol 69 (10) ◽  
pp. 2043-2051 ◽  
Author(s):  
Li Xie ◽  
Hui Liu ◽  
Yin-guang Chen ◽  
Qi Zhou
Keyword(s):  
Fatty Acid ◽  
Chemical Oxygen Demand ◽  
Sodium Acetate ◽  
Volatile Fatty Acid ◽  
Oxygen Demand ◽  
High Strength ◽  
Thin Stillage ◽  
Ph Adjustment ◽  
Adjustment Strategy ◽  
Initial Ph

Volatile fatty acid (VFA) production from three types of high-strength organic wastewater (cassava thin stillage, starch wastewater and yellow-wine processing wastewater) were compared. The results showed that cassava thin stillage was the most suitable substrate, based on its high specific VFA production (0.68 g chemical oxygen demand (COD)/g initial soluble chemical oxygen demand (SCOD)) and yield (0.72 g COD/g SCOD) as well as low nutrient content in the substrate and fermented liquid. The acid fermented cassava thin stillage was evaluated and compared with sodium acetate in a sequencing batch reactor system. Total nitrogen removal efficiency was higher with fermented cassava thin stillage than with the sodium acetate. The effects of pH and a pH-adjustment strategy on VFA production and composition were determined using cassava thin stillage. At an initial pH range of 7–11, a relatively high VFA concentration of about 9 g COD/L was obtained. The specific VFA production (g COD/g initial SCOD) increased from 0.27 to 0.47 to 0.67 at pH 8 and from 0.26 to 0.68 to 0.81 at pH 9 (initial pH, interval pH, and constant pH adjustment, respectively). The dominant VFA species changed significantly with the increasing frequency of the pH adjustment. Further studies will examine the metabolic pathways responsible for VFA composition.

scholarly journals Establishment and Development of Ruminal Hydrogenotrophs in Methanogen-Free Lambs

2007 ◽  
Vol 73 (20) ◽  
pp. 6391-6403 ◽  
Author(s):  
Gérard Fonty ◽  
Keith Joblin ◽  
Michel Chavarot ◽  
Remy Roux ◽  
Graham Naylor ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Volatile Fatty Acid ◽  
Animal Studies ◽  
Age Effect ◽  
High Population Density ◽  
Ruminal Fermentation ◽  
Population Densities ◽  
Age Dependent ◽  
Fibrous Diet ◽  
Reducing Bacteria

ABSTRACT The aim of this work was to determine whether reductive acetogenesis can provide an alternative to methanogenesis in the rumen. Gnotobiotic lambs were inoculated with a functional rumen microbiota lacking methanogens and reared to maturity on a fibrous diet. Lambs with a methanogen-free rumen grew well, and the feed intake and ruminal volatile fatty acid concentrations for lambs lacking ruminal methanogens were lower but not markedly dissimilar from those for conventional lambs reared on the same diet. A high population density (107 to 108 cells g−1) of ruminal acetogens slowly developed in methanogen-free lambs. Sulfate- and fumarate-reducing bacteria were present, but their population densities were highly variable. In methanogen-free lambs, the hydrogen capture from fermentation was low (28 to 46%) in comparison with that in lambs containing ruminal methanogens (>90%). Reductive acetogenesis was not a significant part of ruminal fermentation in conventional lambs but contributed 21 to 25% to the fermentation in methanogen-free meroxenic animals. Ruminal H2 utilization was lower in lambs lacking ruminal methanogens, but when a methanogen-free lamb was inoculated with a methanogen, the ruminal H2 utilization was similar to that in conventional lambs. H2 utilization in lambs containing a normal ruminal microflora was age dependent and increased with the animal age. The animal age effect was less marked in lambs lacking ruminal methanogens. Addition of fumarate to rumen contents from methanogen-free lambs increased H2 utilization. These findings provide the first evidence from animal studies that reductive acetogens can sustain a functional rumen and replace methanogens as a sink for H2 in the rumen.

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