THE ANAEROBIC DISSIMILATION OF D-RIBOSE-1-C14, D-XYLOSE-1-C14, D-XYLOSE-2-C14, AND D-XYLOSE-5-C14 BY AEROBACTER AEROGENES

1955 ◽  
Vol 33 (1) ◽  
pp. 615-621 ◽  
Author(s):  
H. A. Altermatt ◽  
F. J. Simpson ◽  
A. C. Neish

The lactic acid produced from D-ribose-1-C14 or D-xylose-1-C14 had only a trace of isotopic carbon in the carbinol group, while the methyl carbon had 40% and carboxyl carbon 20% of the specific activity of carbon-1 of the pentose. The lactic acid from D-xylose-2-C14 was labelled to a slight extent in the methyl group, while the carbinol carbon and the carboxyl carbon had 40% and 20% respectively of the C14 concentration of carbon-2 of the sugar. D-Xylose-5-C14 gave lactic acid labelled mainly in the methyl carbon, which had about 60% of the specific activity of carbon-5 of the pentose. The other fermentation products (2,3-butanediol, ethanol, acetic acid, formic acid, and carbon dioxide) were labelled as if they had been formed from pyruvate with the same labelling as the lactic acid. These results offer additional support to the hypothesis whereby complete conversion of pentose to triose occurs via a heptulose.

1955 ◽  
Vol 33 (4) ◽  
pp. 615-621 ◽  
Author(s):  
H. A. Altermatt ◽  
F. J. Simpson ◽  
A. C. Neish

The lactic acid produced from D-ribose-1-C14 or D-xylose-1-C14 had only a trace of isotopic carbon in the carbinol group, while the methyl carbon had 40% and carboxyl carbon 20% of the specific activity of carbon-1 of the pentose. The lactic acid from D-xylose-2-C14 was labelled to a slight extent in the methyl group, while the carbinol carbon and the carboxyl carbon had 40% and 20% respectively of the C14 concentration of carbon-2 of the sugar. D-Xylose-5-C14 gave lactic acid labelled mainly in the methyl carbon, which had about 60% of the specific activity of carbon-5 of the pentose. The other fermentation products (2,3-butanediol, ethanol, acetic acid, formic acid, and carbon dioxide) were labelled as if they had been formed from pyruvate with the same labelling as the lactic acid. These results offer additional support to the hypothesis whereby complete conversion of pentose to triose occurs via a heptulose.


1954 ◽  
Vol 32 (1) ◽  
pp. 147-153 ◽  
Author(s):  
A. C. Neish ◽  
F. J. Simpson

D-Glucose-1-C14, D-arabinose-1-C14, and L-arabinose-1-C14 were dissimilated anaerobically by Aerobacter aerogenes. The major products (2,3-butanediol, ethanol, acetic acid, lactic acid, formic acid, and carbon dioxide) were isolated and the location of C14 determined. The products from glucose were all labeled, mainly in the methyl groups, in agreement with the hypothesis that they were derived from methyl-labeled pyruvate formed by the reactions of the classical Embden–Meyerhof scheme for glycolysis. The products from both pentoses appeared to have been formed from pyruvate labeled in both the methyl and carboxyl groups with twice as much C14 in the methyl group as in the carboxyl group. This result may be explained quantitatively by a hypothesis assuming complete conversion of pentose to triose via a heptulose.


1954 ◽  
Vol 32 (3) ◽  
pp. 147-153 ◽  
Author(s):  
A. C. Neish ◽  
F. J. Simpson

D-Glucose-1-C14, D-arabinose-1-C14, and L-arabinose-1-C14 were dissimilated anaerobically by Aerobacter aerogenes. The major products (2,3-butanediol, ethanol, acetic acid, lactic acid, formic acid, and carbon dioxide) were isolated and the location of C14 determined. The products from glucose were all labeled, mainly in the methyl groups, in agreement with the hypothesis that they were derived from methyl-labeled pyruvate formed by the reactions of the classical Embden–Meyerhof scheme for glycolysis. The products from both pentoses appeared to have been formed from pyruvate labeled in both the methyl and carboxyl groups with twice as much C14 in the methyl group as in the carboxyl group. This result may be explained quantitatively by a hypothesis assuming complete conversion of pentose to triose via a heptulose.


1957 ◽  
Vol 35 (1) ◽  
pp. 357-363 ◽  
Author(s):  
E. Bilinski ◽  
W. B. McConnell

Sixteen amino acids were isolated from the gluten of wheat plants, the stems of which had been injected with acetate-1-C14 or -2-C14. With both tracers the C14 labelled amino acids varied markedly from each other in specific activity. Glutamic acid, proline, and arginine were most active, followed by the four-carbon amino acids aspartic acid and threonine, while the short-chain amino acids glycine, alanine, serine, and methionine possessed medium activity. Branched-chain and aromatic amino acids, and the two basic amino acids lysine and histidine were weakly labelled, but showed marked differences from each other not only in specific activity but in the relative amounts of carboxyl and methyl groups of acetate incorporated. Acetate-2-C14 generally gave amino acids of highest activity, but acetate-1-C14 was most effective for labelling glycine, histidine, and serine. Partial degradation by ninhydrin decarboxylation clearly showed that the carboxyl group of acetate tended, in general, to appear to a greater extent in the carboxyl group of amino acids than did the methyl group. Direct incorporation of the carboxyl carbon of acetate in C1 of leucine was observed.


1953 ◽  
Vol 31 (3) ◽  
pp. 265-276 ◽  
Author(s):  
A. C. Neish

Bacillus subtilis (Ford's type) was able to fix only 3% of the NaHC14O3 added during anaerobic dissimilation of glucose, under conditions where Serratia marcescens and Aerobacter aerogenes fixed 38% and 54% respectively. The carbon-14 was found mainly in succinic acid, lactic acid carboxyl, and formic acid, in decreasing order of specific activity. Similar experiments with labelled formate showed it to be relatively inert, most of it being recovered unchanged. Acetate was readily metabolized by B. subtilis during the fermentation of glucose with a marked increase in the amount of 2,3-butanediol and ethanol formed, while the amount of glycerol was decreased to less than one-tenth of the normal value. Experiments with CH3C14OONa proved that the acetate was reduced to ethanol, only traces of acetate carbon being found in 2,3-butanediol or lactic acid. Fermentation of glucose-1-C14 gave 2,3-butanediol and lactic acid labelled in the methyl groups and glycerol labelled mainly in the primary alcohol groups; only a small part of the carbon-14 being found in carbon dioxide.


1957 ◽  
Vol 35 (6) ◽  
pp. 357-363 ◽  
Author(s):  
E. Bilinski ◽  
W. B. McConnell

Sixteen amino acids were isolated from the gluten of wheat plants, the stems of which had been injected with acetate-1-C14 or -2-C14. With both tracers the C14 labelled amino acids varied markedly from each other in specific activity. Glutamic acid, proline, and arginine were most active, followed by the four-carbon amino acids aspartic acid and threonine, while the short-chain amino acids glycine, alanine, serine, and methionine possessed medium activity. Branched-chain and aromatic amino acids, and the two basic amino acids lysine and histidine were weakly labelled, but showed marked differences from each other not only in specific activity but in the relative amounts of carboxyl and methyl groups of acetate incorporated. Acetate-2-C14 generally gave amino acids of highest activity, but acetate-1-C14 was most effective for labelling glycine, histidine, and serine. Partial degradation by ninhydrin decarboxylation clearly showed that the carboxyl group of acetate tended, in general, to appear to a greater extent in the carboxyl group of amino acids than did the methyl group. Direct incorporation of the carboxyl carbon of acetate in C1 of leucine was observed.


Fermentation ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 59
Author(s):  
Timothy J. Tse ◽  
Daniel J. Wiens ◽  
Jianheng Shen ◽  
Aaron D. Beattie ◽  
Martin J. T. Reaney

As barley and oat production have recently increased in Canada, it has become prudent to investigate these cereal crops as potential feedstocks for alcoholic fermentation. Ethanol and other coproduct yields can vary substantially among fermented feedstocks, which currently consist primarily of wheat and corn. In this study, the liquified mash of milled grains from 28 barley (hulled and hull-less) and 12 oat cultivars were fermented with Saccharomyces cerevisiae to determine concentrations of fermentation products (ethanol, isopropanol, acetic acid, lactic acid, succinic acid, α-glycerylphosphorylcholine (α-GPC), and glycerol). On average, the fermentation of barley produced significantly higher amounts of ethanol, isopropanol, acetic acid, succinic acid, α-GPC, and glycerol than that of oats. The best performing barley cultivars were able to produce up to 78.48 g/L (CDC Clear) ethanol and 1.81 g/L α-GPC (CDC Cowboy). Furthermore, the presence of milled hulls did not impact ethanol yield amongst barley cultivars. Due to its superior ethanol yield compared to oats, barley is a suitable feedstock for ethanol production. In addition, the accumulation of α-GPC could add considerable value to the fermentation of these cereal crops.


Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 894
Author(s):  
Johannes Pitsch ◽  
Georg Sandner ◽  
Jakob Huemer ◽  
Maximilian Huemer ◽  
Stefan Huemer ◽  
...  

Fermentable oligo-, di-, and monosaccharides and polyols (FODMAPs) are associated with digestive disorders and with diseases such as irritable bowel syndrome. In this study, we determined the FODMAP contents of bread, bakery products, and flour and assessed the effectiveness of sourdough fermentation for FODMAP reduction. The fermentation products were analyzed to determine the DP 2–7 and DP >7 fructooligosaccharide (FOS) content of rye and wheat sourdoughs. FOSs were reduced by Acetobacter cerevisiae, Acetobacter okinawensis, Fructilactobacillus sanfranciscensis, and Leuconostoc citreum to levels below those in rye (−81%; −97%) and wheat (−90%; −76%) flours. The fermentation temperature influenced the sourdough acetic acid to lactic acid ratios (4:1 at 4 °C; 1:1 at 10 °C). The rye sourdough contained high levels of beneficial arabinose (28.92 g/kg) and mannitol (20.82 g/kg). Our study contributes in-depth knowledge of low-temperature sourdough fermentation in terms of effective FODMAP reduction and concurrent production of desirable fermentation byproducts.


2000 ◽  
Vol 66 (9) ◽  
pp. 3664-3673 ◽  
Author(s):  
Nabil ben Omar ◽  
Fr�d�ric Ampe

ABSTRACT The dynamics of the microbial community responsible for the traditional fermentation of maize in the production of Mexican pozol was investigated by using a polyphasic approach combining (i) microbial enumerations with culture media, (ii) denaturing gradient gel electrophoresis (DGGE) fingerprinting of total community DNA with bacterial and eukaryotic primers and sequencing of partial 16S ribosomal DNA (rDNA) genes, (iii) quantification of rRNAs from dominant microbial taxa by using phylogenetic oligonucleotide probes, and (iv) analysis of sugars and fermentation products. AStreptococcus species dominated the fermentation and accounted for between 25 and 75% of the total flora throughout the process. Results also showed that the initial epiphytic aerobic microflora was replaced in the first 2 days by heterofermentative lactic acid bacteria (LAB), including a close relative ofLactobacillus fermentum, producing lactic acid and ethanol; this heterolactic flora was then progressively replaced by homofermentative LAB (mainly close relatives of L. plantarum, L. casei, and L. delbrueckii) which continued acidification of the maize dough. At the same time, a very diverse community of yeasts and fungi developed, mainly at the periphery of the dough. The analysis of the DGGE patterns obtained with bacterial and eukaryotic primers targeting the 16S and 18S rDNA genes clearly demonstrated that there was a major shift in the community structure after 24 h and that high biodiversity—according to the Shannon-Weaver index—was maintained throughout the process. These results proved that a relatively high number of species, at least six to eight, are needed to perform this traditional lactic acid fermentation. The presence ofBifidobacterium, Enterococcus, and enterobacteria suggests a fecal origin of some important pozol microorganisms. Overall, the results obtained with different culture-dependent or -independent techniques clearly confirmed the importance of developing a polyphasic approach to study the ecology of fermented foods.


2020 ◽  
Vol 8 (12) ◽  
pp. 1916
Author(s):  
Mariana P. Perini ◽  
Mariana F. Rentas ◽  
Raquel Pedreira ◽  
Andressa R. Amaral ◽  
Rafael V. A. Zafalon ◽  
...  

Prebiotics promote health benefits, however, there is no consensus on the minimal intake period required in order to obtain good results. This study evaluated the effect of the time of ingestion of prebiotics on fecal fermentation products and immunological features in dogs. Twenty-four adult dogs were randomly distributed in a block design with six groups and four treatments. Diet and intake period were variation factors. Diets were either a control diet without the addition of prebiotic (CO) or with the inclusion of 1% of a commercial product containing a minimum of 0.38% galactooligosaccharides (GOS), 0.5% (B1) or 1% (B2) of a prebiotic blend. Time variable was set at 30 and 60 days for evaluation of immunity and gut health. Results were analyzed in the Statistical Analysis System software (SAS), version 9.4, considering the repeated measures over time design, and means were compared by the Tukey test and p < 0.05 was significant. Propionic acid was the only variable that had an interaction effect, with reduction of this metabolite in treatment B2 in the period of 60 days. At T60, concentrations of immunoglobulin A, lactic acid, and pH in the feces increased (p < 0.05) in all treatments regardless of prebiotic inclusion or not. GOS increased fecal score and lactic acid concentrations. Therefore, a 60-day intake period of a prebiotic blend was not sufficient to modulate fecal and immune variables and higher concentrations of a single prebiotic would be more relevant for results.


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