Effects of nutrient limitation on the anaerobic upflow sludge blanket reactor

Goodwin, J.A.S.; Wase, D. A. J.; Forster, C.F.

doi:10.1016/0141-0229(90)90026-m

Cited by 38 publications

(13 citation statements)

References 18 publications

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“…Therefore, by comparing the Fe concentration in pure methanogenic culture and in the granules, and the Fe status in the granules, it is suggested that the bacteria grown in the reactors without the Fe and Co supplementation may be Fe and/or Co deficient. When bacteria are under Fe and/or Co deficiency, their specific activities are lower than that of bacteria grown under normal conditions (Goodwin et al 1990). The low specific activity of bacteria grown in reactors deficient in Fe and/or Co may also support the conclusion that these bacteria were Fe and/or Co deficient.…”

Section: Discussionmentioning

confidence: 99%

Properties of anaerobic granular sludge as affected by yeast extract, cobalt and iron supplements

Shen

Kosaric

Błaszczyk

1993

Appl Microbiol Biotechnol

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The effect of yeast extract (YE), iron (Fe) and cobalt (Co) on anaerobic bacterial granules grown in eight laboratory-scale upflow anaerobic sludge blanket reactors was investigated using a factorial design. The experiment was performed in three periods in which different chemical oxygen demand (COD) loading rates were applied to the reactors. The COD digestion rate and the specific activity of the bacteria were positively affected by supplementation of Fe and Co in the feed under a high COD loading rate. YE had a strong positive effect on the bacterial growth rate, but no significant effect on the specific activity of the bacteria. With Fe supplementation, an excellent COD digestion rate was maintained in the reactors, and addition of YE in the feed was not necessary. Granules with better settling properties were developed under a relatively low bacterial growth rate. With the increase in COD loading rate, the percentage of calcium increased rapidly in the granules from the reactors without YE supplementation. The bacteria grown under high COD loading rate and without an Fe supplement could be Fe-deficient. Methanothrix-like rod-shaped bacteria were dominant in the granules from all reactors.

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Section: Discussionmentioning

confidence: 99%

Properties of anaerobic granular sludge as affected by yeast extract, cobalt and iron supplements

Shen

Kosaric

Błaszczyk

1993

Appl Microbiol Biotechnol

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“…Nevertheless, in the present in vitro study using Ca levels close to the lower level recommended, the increase in Ca content of the diet numerically enhanced (P < 0.1) NDF degradation rate. Calcium supplementation may stimulate methane production by methanogens as was shown in a pure culture study with Methanosarcina barkeri (Chattopadhyay et al 1993) and with methanogens present in anaerobic bioreactors (Goodwin et al 1990). This was also obvious as a weak trend (+10%) in the present study in the treatments without C 12:0 supply.…”

Section: Effects Of Calcium On Rumen Microbes and Ruminal Methanogenesismentioning

confidence: 99%

In vitro ruminal methane suppression by lauric acid as influenced by dietary calcium

Machmüller

Soliva²,

Kreuzer³

2002

Can. J. Anim. Sci.

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Machmüller, A., Soliva, C. R. and Kreuzer, M. 2002. In vitro ruminal methane suppression by lauric acid as influenced by dietary calcium. Can. J. Anim. Sci. 82: 233-239. The effect of Ca supplementation on the methane-suppressing effect of lauric acid was investigated in an experiment based on a 2 × 2-factorial arrangement using the in vitro system Rusitec. Additional Ca was supplemented at 1 g kg -1 diet in the form of compounds of relatively low solubility in rumen fluid. Lauric acid (C 12:0 ), the predominant effective medium-chain fatty acid in coconut oil, was added at a level of 50 g kg -1 . Adding C 12:0 did not affect bacterial count, but eliminated ciliate protozoa from fermenters. Ammonia concentration in fermentation mixture declined and volatile fatty acid pattern changed with C 12:0 . The apparent degradation rate of total organic matter was not altered by C 12:0 , but fiber fermentation was depressed (P < 0.001). Effects of Ca on microbial counts and fermentation characteristics remained low. Without additional Ca, C 12:0 reduced the average daily methane release (mmol g -1 organic matter degraded) by 76%. In comparison, C 12:0 only reduced methane production by 47% when additional Ca was included in the diet (interaction of C 12:0 and Ca, P < 0.05). The present results suggest that the dietary content of soap-forming Ca has to be kept low in order to achieve a high methane-suppressing effect of lauric acid.Key words: Methane, lauric acid, lipids, calcium, Rusitec, ruminants Machmüller, A., Soliva, C. R. et Kreuzer, M. 2002. Effets du calcium alimentaire sur la suppression in vitro du méthane par de l'acide laurique dans le rumen. Can. J. Anim. Sci. 82: 233-239. L'influence d'une supplémentation de calcium sur l'effet inhibiteur de l'acide laurique sur la méthanogenèse a été examiné dans un essai à 2 × 2-facteurs employant un système in vitro Rusitec. Le calcium a été rajouté à la ration à raison de 1 g kg -1 sous forme de composantes relativement peu solubles dans le liquide ruménal. De l'acide laurique (C 12:0 ), l'acide gras à chaînes moyennes prédominant et le plus efficace dans l'huile de coco, a été rajouté à raison de 50 g kg -1 . L'adjonction de C 12:0 n'a pas affecté le nombre de bactéries, mais a éliminé les protozoaires ciliés du fermenteurs. La concentration d'ammoniac dans le liquide de fermentation a diminué et le profil des acides gras volatils a été modifié par le C 12:0 . La dégradabilité apparente de la matière organique totale n'a pas été altérée par le C 12:0 , mais la fermentation des fibres a baissé (P < 0.001). Les effets du Ca sur le nombre de microorganismes et sur les caractéristiques de fermentation sont restés moindres. Le C 12:0 seul, sans adjonction de Ca, a réduit la production journalière moyenne de méthane (mmol g -1 de matière organique dégradée) de 76%. En comparaison, la réduction n'a été que de 47% en rajoutant le Ca à la ration (interaction entre C 12:0 et Ca, P < 0.05). Ces résultats suggèrent que la teneur de la ration en Ca actif dans la saponification doit ...

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“…Besides macronutrients, micronutrients are also required [1,2], e.g. Besides macronutrients, micronutrients are also required [1,2], e.g.…”

Section: Introductionmentioning

confidence: 99%

Bonding Form Analysis of Metals and Sulfur Fractionation in Methanol‐Grown Anaerobic Granular Sludge

Veen

Fermoso

Lens

2007

Engineering in Life Sciences

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This study investigates the metal and sulfur bonding form distribution in mesophilic (30 °C, pH 7) methanol‐grown anaerobic granular sludge from upflow anaerobic sludge bed reactors operating at an organic loading rate of 3.8 g CH3OH‐COD/L d. This was achieved by applying a modified Tessier sequential extraction scheme to investigate the metal bonding forms and a sequential extraction scheme for sulfur and simultaneously extracted metals to granular sludge samples of the reactors after 0, 22, 35 and 43 days of operation. Metals were also determined in the sulfur extracts. Co and Ni predominated in their oxidizable bonding forms, which increased together with the pseudo‐total content during reactor operation. An omission of Co and Ni from the influent led to only a minor decline of the pseudo‐total content in the sludge, mainly from the acid‐soluble fraction. The ratio of simultaneously extracted metals (Co, Fe, Mn, Ni) to acid‐volatile sulfides was lower than 1, indicating that the sludge contained sufficient sulfide to bind the metals as metal monosulfides. The bioavailability of metals in the methanol‐grown anaerobic granular sludge investigated is therefore mainly controlled by sulfide formation/dissolution.

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Effects of nutrient limitation on the anaerobic upflow sludge blanket reactor

Cited by 38 publications

References 18 publications

Properties of anaerobic granular sludge as affected by yeast extract, cobalt and iron supplements

Properties of anaerobic granular sludge as affected by yeast extract, cobalt and iron supplements

In vitro ruminal methane suppression by lauric acid as influenced by dietary calcium

Bonding Form Analysis of Metals and Sulfur Fractionation in Methanol‐Grown Anaerobic Granular Sludge

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