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PubMed1987

Effect of human faecal inoculum on in vitro fermentation variables.

1. Homogenized and diluted faeces (66.6 g/l) collected from one human source on three different months was incubated with four standard substrates (oat bran, wheat bran, red kidney beans (Phaseolus vulgaris) and guar gum) for 4, 8, 12 and 24 h. 2. Neutral-detergent fibre and organic matter (OM) digestibility measurements and gas production (ml gas/g OM) were influenced by substrate and incubation period but not by day of collection. 3. Production of short-chain fatty acids (SCFA) (mmol/g OM) was a function of substrate and incubation period but not day of collection at 4, 8 and 12 h. Rapidly fermentable substrates such as red kidney beans and guar gum did not ferment beyond 12 h and SCFA values were not different at 24 h. 4. Substrates differed in amount, rate and type of SCFA produced. 5. The results indicate that human faeces collected on different occasions were sufficiently uniform to yield similar in vitro fermentation findings among collections. Therefore, it is concluded that human faecal material is a practical source of micro-organisms to evaluate the fermentation properties of substrates.

Dietary Fiber↗
PubMed1993

Fermentation and subsequent disposition of 14C-labelled plant cell wall material in the rat.

A 14C-labelled plant cell wall preparation (14C-PCW) produced from spinach (Spinacia oleracea L.) cell culture exhibits uniform labelling of the major polysaccharide groups (%): pectins 53, hemicellulose 13, cellulose 21, starch 3. This 14C-PCW preparation has been used in rat studies as a marker for plant cell wall metabolism. Metabolism of the 14C-PCW occurred largely over the first 24 h. This was due to fermentation in the caecum. The pectic fraction of the plant cell walls was degraded completely in the rat gastrointestinal tract, but some [14C]cellulose was still detected after 24 h in the colon. Of the 14C, 22% was recovered in the host liver, adipose tissue and skin, 26% excreted as 14CO2 and up to 18% was excreted in the faeces. There was no urinary excretion of 14C. In vitro fermentation using a caecal inoculum showed reduced 14CO2 production, 12% compared with 26% in the intact rat. 14C-PCW is a useful marker to investigate the fate of plant cell wall materials in the gastrointestinal tract. These studies show both bacterial fermentation of the 14C-PCW and host metabolism of the 14C-labelled fermentation products.

Animals↗
PubMed1993

Assessment of fermentation in growing pigs given unmolassed sugar-beet pulp: a stoichiometric approach.

In four experiments growing pigs were given a cereal-based diet alone or supplemented with unmolassed sugar-beet pulp (SBP), used as a model substrate for fermentation. The rates of production of methane and gaseous hydrogen were measured and, together with the molar proportions of volatile fatty acids (VFA) in the digesta, used in stoichiometric calculations of fermentation. The resulting estimates were only one-sixth of the observed extent of digestion of SBP. Bacteriostatic levels of antibiotics reduced fermentation by more than half, as judged from the digestion of non-starch polysaccharides: allowing for the incomplete suppression of fermentation it was estimated that the production of methane and VFA could account completely for the digested SBP. The potential contribution of various routes of hydrogen disposal to the error of the stoichiometric calculations is discussed.

Animals↗
PubMed1993

Sugar composition of dietary fibre and short-chain fatty acid production during in vitro fermentation by human bacteria.

The aim of the present study was to assess the relationship between the disappearance of dietary fibre sugars and the production of individual short-chain fatty acids (SCFA). The bacterial degradation of five dietary fibres whose sugars were quantified was investigated in vitro using a human faecal inoculum. Involvement of the main fibre sugars in SCFA production was evaluated by a stepwise multiple linear regression. The results show first that the nature and chiefly the associations between the fibre sugars were key variables in the fermentability. Second, the nature and the amounts of SCFA produced were closely related to the in vitro fermentation of the main sugars available: uronic acids seemed to be principally involved in the production of acetic acid whereas the production of propionic acid could be promoted by the fermentation of glucose and, to a lesser extent, by that of xylose and arabinose. Xylose tended to have a greater impact than uronic acids and glucose on the production of butyric acid. Thus, it would be possible to predict which SCFA could be specifically produced during the fermentation of a fibre, as far as the chemical composition and structure of this fibre are known.

Acetates↗
PubMed1995

Taurocholic acid adsorption during non-starch polysaccharide fermentation: an in vitro study.

The association of radiolabelled taurocholic acid with the solid fraction of a faecal fermentation mixture was measured. A human faecal inoculum was incubated with [24-14C]taurocholic acid and several non-starch polysaccharide sources (pectin, wheat bran, ispaghula (Plantago ovata) husk and seed), glucose or a substrate-free control. Portions of fermentation mixture were taken at 0, 3, 6, 21 and 24 h and centrifuged to acquire a supernatant fraction and a pellet containing the fermentation residue. 14C was measured in supernatant fractions and pellets at all time points. Volatile fatty acids (VFA) were measured at 0 and 24 h to confirm bacterial growth. Radioactivity in the pellet increased over time for all substrates. Glucose resulted in the greatest incorporation of taurocholic acid into the pellet, followed by pectin. At 24 h the proportion of the total radioactivity found in the pellet was 92% for glucose, 79% for pectin, 60% for wheat bran, 59% for ispaghula seed, 53% for ispaghula husk and 26% for the control (mean of duplicates). Glucose and pectin produced the greatest quantity of VFA at 24 h. VFA production was highly correlated with radioactivity in the pellet (r0.976, P < 0.005). These results suggest that the bile acid binding capacity of a faecal culture mixture may be strongly influenced by the fermentability of the available substrate and hence related to bacterial metabolic activity.

Adsorption↗
PubMed1995

Estimation of the fermentability of dietary fibre in vitro: a European interlaboratory study.

Five European laboratories tested a simple in vitro batch system for dietary fibre fermentation studies. The inoculum was composed of fresh human faeces mixed with a carbonate-phosphate buffer complex supplemented with trace elements and urea. Five dietary fibre sources (cellulose, sugarbeet fibre, soyabean fibre, maize bran and pectin) were used by each laboratory on three occasions to determine pH, residual non-starch polysaccharides (NSP) and short-chain fatty acid production during fermentation. Cellulose and maize bran degradabilities were very low (7.2(SE 10.8) and 6.2 (SE 9.1)% respectively after 24 h), whereas pectin and soyabean fibre were highly degraded (97.4 (SE 4.4) and 91.1 (SE 3.4)% respectively after 24 h). Sugarbeet fibre exhibited an intermediate level of degradability (59.5 (SE 14.9)%). Short-chain fatty acid production was closely related to NSP degradation (r 0.99). Although each variable was ranked similarly by all laboratories, some differences occurred with respect to absolute values. However, the adaptation of donors to the experimental substrates was not an influential factor. Interlaboratory differences could be reduced either by adding less substrate during incubations or using less-diluted inocula. In vitro fermentations with inocula made from human faeces and from rat caecal contents gave similar results. There was a close correspondence between the data obtained in the present experiment and those previously published in in vivo studies in the rat using the same fibres. The in vitro batch system tested during the present study provides a rapid means of obtaining quantitative estimates of the fermentation and the estimation of the energy content of new sources of dietary fibre.

Animals↗
PubMed1996

Acidic fermentation in the caecum increases absorption of calcium and magnesium in the large intestine of the rat.

The effect of fermentation on colonic absorption of Ca and Mg was investigated in 8-week-old rats adapted to diets containing either digestible wheat starch (DS diets) or including resistant starch, i.e. 350 g raw potato starch/kg (RS diets). The dietary Ca level of the DS and RS diets was 2.5 or 7.5 g/kg. RS diets resulted in enlargements of the caecum together with hypertrophy of the caecal wall. Acidification of the caecal contents by microbial fermentation of RS was influenced by the dietary Ca level. Very acidic pH conditions and relatively low concentrations of short-chain fatty acids, in the presence of lactic acid fermentation, were observed with the 2.5 g Ca/kg level. Rats fed on RS diets had a higher percentage of soluble Ca (and inorganic phosphate) in the caecum, particularly of rats adapted to the high Ca level. As a result of the hypertrophy of the caecal wall and of an elevated concentration of soluble Ca, the caecal absorption of Ca was 5-6-fold higher in the RS groups than in the DS groups. The difference between dietary intake and faecal excretion (DI-FE) of Ca was higher in rats fed on RS diets than in those fed on DS diets, when the dietary Ca level was 2.5 g/kg. With the higher Ca intake the elevated rate of Ca absorption from the caecum in RS-fed rats was not paralleled by an enhanced DI-EE difference: this suggests a shift of the Ca absorption towards the large intestine. Feeding RS diets also enhanced Mg caecal absorption, resulting in a substantially higher DI-FE difference for Mg, especially with the 2.5 g Ca/kg diets, because a high Ca intake tends to inhibit Mg absorption. The present findings support the view that the large intestine may represent a major site of Ca (and Mg) absorption when acidic fermentations take place. This process could improve the digestive Ca balance when the dietary Ca supply is low; when the Ca supply is affluent, it rather shifts Ca absorption towards a more distal site of the digestive tract.

Animals↗
PubMed1996

The influence of dietary fibre and environmental temperature on the development of the gastrointestinal tract, digestibility, degree of fermentation in the hind-gut and energy metabolism in pigs.

The present study was undertaken to provide detailed information about the effect of dietary fibre (DF) level on the development of the digestive tract, on nutrient digestibility and on energy and protein metabolism of pigs housed in low (13 degrees) or high (23 degrees) thermal environments. Low- and high-fibre diets (59 v. 268 g DF/kg DM) were studied in three balance periods with fistulated pigs in the weight range 45-120 kg. Heat production was measured using open-circuit respiration chambers. Pea fibre and pectin were used to adjust the DF level in the high-fibre diet. Per kg empty body weight the stomach, caecum and colon and the length of colon were significantly greater in pigs consuming the high-fibre diet than in those on the low-fibre diet. Pigs kept at low temperature had significantly heavier caecums than those kept at the high temperature. Digestibilities of protein, DM and energy were lowest for the high-fibre diet. Only minor amounts of NSP and its constituent sugars were degraded anterior to the ileum, whereas in the hind-gut the fermentation of the total NSP fraction was high, being 0.77 for the high-fibre diet and 0.59 for the low-fibre diet. Feeding the high-fibre diet increased the flow of digesta through the terminal ileum 5-6-fold and an extra 460 g organic matter was fermented daily in the hind-gut compared with pigs fed on the low-fibre diet. The amount of retained energy as a proportion of metabolizable energy decreased in relation to the amount of energy fermented in the hind-gut. Based on the present data it was estimated that the relative value of energy derived from hind-gut fermentation was 0.73 in comparison with energy enzymically digested in the small intestine. There was negligible effect of the temperature--fibre interaction on energy metabolism. However, it could be calculated that the decrease in temperature from 23 degrees to 13 degrees was associated with an increase in heat production by 2.9 MJ/pig per d.

Animals↗
PubMed2001

Effects of two fermentable carbohydrates (inulin and resistant starch) and their combination on calcium and magnesium balance in rats.

Resistant starch and inulin are complex carbohydrates that are fermented by the microflora and known to increase colonic absorption of minerals in animals. The fermentation of these substrates in the large bowel to short-chain fatty acids is the main reason for this increase in mineral absorption. The purpose of the present study was to examine the potential synergistic effect of a combination of these two fermentable carbohydrates. For this purpose, thirty-two adult male Wistar rats weighing 200 g were used in the present study. The rats were distributed into four groups, and fed for 21 d a fibre-free basal purified diet or diet containing 100 g inulin, or 150 g resistant starch (raw potato starch)/kg diet or a blend of 50 g inulin and 75 g resistant starch/kg diet. After an adaptation period of 14 d, the rats were then transferred to metabolic cages and dietary intake, faeces and urine were monitored for 5 d. The animals were then anaesthetized and caecal Ca and Mg absorption were measured. Finally, the rats were killed and blood, caecum and tissues were sampled. Ca and Mg levels were assessed in diets, faeces, urine, caecum and plasma by atomic absorption spectrometry. Our results confirmed that inulin and resistant starch ingestion led to considerable caecal fermentation in the three experimental groups compared with the control group diet. Moreover, both carbohydrates significantly increased the intestinal absorption and balance of Ca and Mg, without altering the plasma level of these two minerals. Interestingly, the combination of the studied carbohydrates increased significantly the caecal soluble Ca and Mg concentrations, the apparent intestinal absorption and balance of Ca, and non-significantly the plasma Mg level. In conclusion, a combination of different carbohydrates showed synergistic effects on intestinal Ca absorption and balance in rats. Further studies with other types of carbohydrate combinations should be carried out to extend these findings.

Animals↗
PubMed2000

Persistence of Lactobacillus plantarum DSM 9843 on human tonsillar surface after oral administration in fermented oatmeal gruel. A pilot study.

The occurrence of Lactobacillus plantarum DSM 9843 on tonsillar scrapings was studied after single-dose administration. Six healthy volunteers gargled 100 ml of fermented oatmeal gruel containing 2 x 10(11) colony forming units (cfu) of Lb. plantarum DSM 9843 for 2 min and then swallowed it. Two healthy volunteers drank 50 ml fermented oatmeal gruel (containing 1 x 10(11) cfu of Lb. plantarum DSM 9843) mixed with 50 ml fruit juice, and in another experiment, 5 ml fermented oatmeal gruel (containing 1 x 10(10) cfu of Lb. plantarum DSM 9843) mixed with 95 ml fruit juice. Lb. plantarum DSM 9843 were found in tonsillar scrapings 4-8 h after intake of 2 x 10(11) cfu, for 5-8 h after intake of 1 x 10(11) cfu, and finally up to 4 h after intake of 1 x 10(10) cfu. On electron microscopy micrographs, short rod-shaped bacteria were visible 1 h after intake of the fermented oatmeal gruel, but not 2 h after intake. The results suggest that Lb. plantarum DSM 9843 possess an ability to adhere to tonsillar cells.

Administration, Oral↗
PubMed1996

Increased small intestinal fermentation is partly responsible for the anti-nutritive activity of non-starch polysaccharides in chickens.

1. The mechanism of the anti-nutritive activities of soluble non-starch polysaccharides (NSPs) in broiler diets was investigated with emphasis on the inter-relationship between viscosity and fermentation along the gut. Isolated soluble NSP were added to a control diet to effect high gut viscosity, and in vivo depolymerisation of the NSP was achieved using a commercial glycanase. 2. Addition of soluble NSPs significantly (P < 0.01) increased gut viscosity, reduced the AME of the diet and depressed the growth and FCE of the birds. Enzyme supplementation of the NSP-enriched diet reversed the adverse effects, increasing (P < 0.01) weight gain, FCE and AME. Comparisons of the viscosities (mPa) in birds fed on the NSP-enriched diet and the same diet supplemented with enzyme were respectively: 11.9 v. 2.3 in the duodenum; 78.3 v. 4.4 in the jejunum and 409.3 v. 10.8 in the ileum. 3. Caecal volatile fatty acid concentration was markedly (P < 0.01) elevated by enzyme supplementation, whereas ileal fermentation was inhibited. 4. Microscopic examination revealed that, among birds fed on the NSP-enriched diet, there had been extensive small intestinal fermentation, which was eliminated by the enzyme supplementation. 5. Addition of a synthetic antibiotic (Amoxil) had no beneficial effects. 6. The current study demonstrated that increased fermentation occurs in the small intestine when a large amount of viscous NSPs is present in the diet and this is detrimental to the performance and well-being of poultry.

Animal Feed↗
PubMed1993

Microbial and nutritional aspects of feeding fermented feed (poultry by-products) to pigs.

Broiler by-products (heads, feet, and viscera) mixed with 4% dextrose were pasteurized for 4 min at 90 degrees C core temperature, cooled to 20 degrees C, and fermented with Lactobacillus plantarum as starter culture. These fermented poultry by-products were fed to 12 individually housed fattening pigs as part (17.6% of the dry matter) of their fattening ration, the remainder composed of compound pig feed. Control pigs received a compound pig feed only. Both groups of pigs were fed restrictively on the basis of body weight. The technical results of the pigs fed the experimental diet showed a significantly improved feed:gain ratio (2.46 vs 2.57), a significantly higher carcass weight (86.1 vs 81.8 kg), a lower meat percentage (50.9 vs 52.5%) and an increased backfat thickness (21.5 vs 18.7%). The bacterial flora in the intestinal tract of the pigs fed the experimental diet differed significantly from the control animals. Decreased colony counts of mesophilic aerobic bacteria, Enterobacteriaceae, enterococci and lactobacilli were found in the rectal content and the prevalence of salmonella was lower. It is suggested that the improved feed:gain ratio and the reduced bacterial activity of the measured groups of bacteria is a result of 1) the higher energy content of the diet, and(or) 2) an assumed enhanced digestibility of nutritional components in the diet, and(or) 3) the lower incidence of diarrhea in the pigs fed with fermented poultry by-products. This resulted in a lower contamination level of enteropathogenic bacteria like, salmonella and Escherichia coli, in the gastro-intestinal tract of the pigs fed fermented poultry by-products.

Animal Feed↗
PubMed2004

Effect and stability of gliotoxin, an Aspergillus fumigatus toxin, on in vitro rumen fermentation.

Aspergillus fumigatus is a toxicogenic fungus usually found in contaminated animal feeds, especially in conserved forages where it can produce several mycotoxins. Gliotoxin, one of the most important toxic metabolites produced by this fungus, has antibacterial, immunosuppressive and apoptotic effects. Ruminants due to the high proportion of forages they receive in the ration would be particularly exposed to gliotoxin. The objective of this work was (1) to assess the effect of gliotoxin on in vitro rumen fermentation and (2) to determine the effect of fermentation on gliotoxin stability. Gliotoxin did not affect rumen fermentation at concentrations found in naturally contaminated feeds. No effects were observed up to a concentration of 20 microg toxin ml(-1) and an extremely high toxin concentration (80 microg ml(-1)) was necessary to affect dry matter degradation, gas and total volatile fatty acids production by 24, 37 and 18%, respectively (p < 0.01). In addition, the toxin was unstable in the rumen environment with 90% disappearance at 6 h of incubation (p < 0.05). In contrast, extracts of A. fumigatus cultures containing gliotoxin at concentrations several times lower than that used for experiments with pure toxin had a negative effect on fermentations indicating the toxicity and possible synergism of other metabolites produced by this fungus. Extracts containing 8.8 microg gliotoxin ml(-1) decreased dry matter degradation, gas and volatile fatty acids production by 28, 46 and 35%, respectively (p < 0.01). Identification of these toxic metabolites and assessment of the rate of passage of gliotoxin to the lower intestinal tract is necessary to evaluate the potential risk of these toxins to ruminants.

Animal Feed↗
PubMed1995

Clinical trial of fermented maize-based oral rehydration solution in the management of acute diarrhoea in children.

In an effort to identify appropriate fluids available in the home for oral rehydration therapy in Ghana, a study was designed to investigate the efficacy of fermented maize gruel, a popular Ghanaian traditional food, in the management of acute diarrhoea. Altogether 108 children aged between 4 and 27 months presenting with acute diarrhoea at the Princess Marie Louise Children's Hospital in Accra, with mild to moderately severe dehydration, were randomly assigned to treatment with either WHO/UNICEF oral rehydration solution (ORS) or fermented and unfermented maize solutions. About 35 children were admitted to each of the three treatment groups. Treatment with the rehydration fluid was maintained for 24 h. Efficacy of the various treatments, assessed in terms of fluid intake, stool output, stool frequency, weight gain and duration of diarrhoea, showed no significant variation among the three groups. The results indicate that the maize solutions were as effective as WHO/UNICEF ORS for oral rehydration therapy. However, the fermented maize was more readily accepted by the children than the unfermented solution. Because fermented maize gruel is widely consumed, inexpensive, readily available, and culturally acceptable to most communities in Ghana, it may be recommended as an appropriate home-available fluid for the management of acute diarrhoea in children at the community level.

Acute Disease↗
PubMed2003

Passage of Salmonella through the crop and gizzard of broiler chickens fed with fermented liquid feed.

In vivo experiments were conducted in order to investigate the passage and bacterial reduction of Salmonella in the crop and gizzard of chickens when fed two different feeds. The chickens were fed dry conventional feed and fermented liquid feed. The fermented feed contains a relatively high concentration of lactic and acetic acid and lactobacilli. One and three week old broiler chickens were necropsied at short intervals after inoculation with Salmonella Enteritidis. Counts of Salmonella from the crop, gizzard, duodenum, caecum and colon/rectum were obtained. This revealed a sharper decrease of Salmonella in the anterior parts of the gastro-intestinal tract in chickens fed with fermented feed than in chickens fed dry feed. It is therefore concluded that fermented feed improves the barrier formed by the crop and gizzard. The reduction of Salmonella is fully realised in the crop and gizzard. The lower intestinal compartment did not show a substantial effect on the reduction of Salmonella. The performed in vivo method appeared to be an appropriate way to study intervention strategies that aim to control Salmonella by improving the barrier function of the upper gastro-intestinal tract.

Animal Feed↗
PubMed1997

Balancing phosphine in manure fermentation.

The evolution of phosphine gas during the anaerobic batch fermentation of fresh swine manure was detected and correlated to the production of methane and hydrogen sulphide. A close temporal relationship between phosphine liberation and methane formation was found. However, the gaseous phosphine released from manure during fermentation only represents a tiny fraction of the overall phosphine balance. The majority of phosphine is captured in solid manure constituents. This matrix-bound phosphine is eliminated by more than 50% during anaerobic batch-fermentation. Seasonally determined phosphine concentrations in biogas and manure from two large-scale manure treatment plants also revealed net losses of phosphine in fermentation. Consequently, manure has to be considered more as a sink of phosphine rather than a phosphine-generating medium. Furthermore, a close relationship between phosphine in the feed of swine and manure of these swine was observed, implying that phosphine residues in the feed (possibly as a result of grain fumigation) represent an important source of phosphine in manure technologies that is relevant before the faecals of swine enter manure treatment plants.

Air Pollutants↗
PubMed2005

Effect of powdered fermented milk with Lactobacillus helveticus on subjects with high-normal blood pressure or mild hypertension.

OBJECTIVE: Two tripeptides (Val-Pro-Pro and Ile-Pro-Pro) that have inhibitory activities for angiotensin I-converting enzyme are produced in milk fermented with Lactobacillus helveticus. In this study we evaluated the effect and safety of powdered fermented milk with L. helveticus CM4 on subjects with high-normal blood pressure or mild hypertension. METHODS: A randomized, placebo-controlled, double-blind study was conducted using 40 subjects with high-normal blood pressure (HN group) and 40 subjects with mild hypertension (MH group). Each subject ingested 6 test tablets (12 g) containing powdered fermented milk with L. helveticus CM4 daily for 4 weeks (test group) or the same amount of placebo tablets for 4 weeks (placebo group). RESULTS: During treatment, the decrease in systolic blood pressure (SBP) and diastolic blood pressure (DBP) in the test group tended to be greater than in the placebo group for both blood pressure groups. At the end of treatment (week 4), a significant decrease in DBP in the HN group was observed (i.e. 5.0 mm Hg (0.1, 9.9; p = 0.04) compared with the placebo group). There was no significant change in SBP (3.2 mm Hg (95% CI -2.6, 8.9; p = 0.27). In the MH group, SBP decreased by 11.2 mm Hg (4.0, 18.4; p = 0.003) and there was a statistically non-significant decrease in DBP of 6.5 mm Hg (-0.1, 13.0; p = 0.055) compared with the placebo group. No marked changes were observed in other indexes, including pulse rate, body weight and blood serum variables, and no adverse effects attributed to the treatment was found in each group. CONCLUSIONS: Daily ingestion of the tablets containing powdered fermented milk with L. helveticus CM4 in subjects with high-normal blood pressure or mild hypertension reduces elevated blood pressure without any adverse effects.

Animals↗
PubMed2002

Acidogenic fermentation: utilization of wasted sludge as a carbon source in the denitrification process.

Laboratory scale batch experiments were conducted at 20 degrees C to investigate the acidogenic fermentation for the conversion of wasted sludge into short chain fatty acids (SCFA) to be utilized as a carbon source in the denitrification process. Hydraulic retention time (HRT), volatile solid (VS) loading rate and pH were studied as these are the important parameters governing the production of volatile fatty acids (VFA). Four different phases were investigated by varying these parameters. HRT was varied from 2.7 to 8.2 days whereas VS loading rate was varied from 1.2 to 3.6 g d(-1). VFA production decreased with the increase in HRT above 2.7 days. 538.37+/-19.39 mg VFA(produced) x d(-1) (0.176+/-0.010 mg VFA(produced) mg(-1) VS(feed) was found as the maximum value of VFA at 2.7 days. The present results based on wasted sludge showed that almost 0.0483+/-0.0016 mg VFA (as COD mg(-1) initial COD) and about 5% of soluble COD production were achieved, which are slightly less than the results reported for primary sludges. The rates of VFA production increased with the increase in VS, however, opposite results were obtained when pH was increased in the reactor. SCFA/FA ratios during fermentation were found in the range of 67-73%. The specific denitrification rates (SDNR) of methanol (2.20+/-0.44 mg NO3-N g(-1) MLVSS x h(-1)) and the fermenter supernatant (2.00+/-0.45 mg NO3-N g(-1) MLVSS x h(-1)) were found to be comparable. Fermenter supernatant, therefore, has the potential to be utilized as a carbon source. However, the results need to be investigated further on a larger scale to ascertain their validity.

Biodegradation, Environmental↗