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Table 1 End products from in vitro switchgrass fermentations by mixed ruminal microorganisms in the presence or absence of redox dyes

From: Redox mediators modify end product distribution in biomass fermentations by mixed ruminal microbes in vitro

Product

Net umol producta

SEDb

Model P > F

Methyl viologen (0.5 mM)

Neutral red (1.0 mM)

Safranin O (1.0 mM)

Control (no dye)

Methane

122.1 A

62.1 B

38.5 B

139.2 A

9.9

<0.0001

Acetate

269.8 A

182.0 B

142.9 B

305.6 A

13.7

<0.0001

Propionate

60.4 C

119.7 A

48.0 C

91.0 B

5.0

<0.0001

Butyrate

24.0 B

40.2 AB

48.8 A

38.8 AB

5.9

0.018

Isobutyrate

9.7 A

4.3 B

0.8 C

1.8 C

0.7

<0.0001

Valerate

6.8 B

35.9 A

1.5 C

5.3 BC

1.4

<0.0001

Isoval + 2 MBc

19.1 A

14.4 B

0.1 C

1.4 C

1.0

<0.0001

Caproate

6.7 A

8.1 A

0.3 B

2.1 B

1.6

0.003

Total VFA

399.1 A

404.1 A

242.3 B

441.5 A

15.4

<0.0001

Total VFA-C

1025.6 B

1201.3 A

629.6 C

1,092.0 AB

40.5

<0.0001

ACLd

2.58 B

2.97 A

2.61 B

2.42 C

0.04

<0.0001

Enthalpy of combustion, kJ

0.602 B

0.667 A

0.343 C

0.633 AB

0.009

<0.0001

  1. Vials contained 100 mg switchgrass and 3.0 mL of diluted mixed ruminal inoculum in a total liquid volume of 10 mL.
  2. aValues are least-square means from triplicate cultures after 72 h incubation, after correction for inoculated blank vials lacking switchgrass. Values within row having different letters (A, B, C) differ (P < 0.05).
  3. bPooled standard error of the difference.
  4. cIsovalerate plus 2-methylbutyrate (chromatographically co-eluting isomers).
  5. dAverage chain length of VFA.