Table 2 Microbial reaction rates per volume of porewater for the different grain size fractions.

From: The effect of sediment grain properties and porewater flow on microbial abundance and respiration in permeable sediments

Fraction

Total Organic Carbon

Median Grain Size

Cell Counts

Oxygen Respiration

Denitrification

NOX Production

wt.%

(µm)

(cells cm−3)

(µmol l−1 h−1)

(µmol l−1 h−1)

(µmol l−1 h−1)

1 (mixed)

0.13

496

5.4(0.2)·108

62(2)

65* (3)

8.4(0.8)

5.8(0.8)

2 (<355 µm)

0.19

277

4.4(0.2)·108

42(2)

43* (2)

6.1(0.2)

4.4(0.8)

3 (355 µm – 500 µm)

0.18

481

2.9(0.1)·108

27(2)

26* (1)

3.7(0.3)

3.3(0.5)

4 (500 µm − 710 µm)

0.17

621

2.7(0.2)·108

27(3)

27* (2)

3.8(0.1)

2.3(0.5)

5 (710 µm – 1000 µm)

0.15

882

3.5(0.3)·108

32(4)

32* (3)

4.1(0.4)

2.4(0.4)

  1. The cell numbers are presented in cell counts per cubic centimeter of wet sediment. The oxygen respiration rates are shown as averages and those marked by (*) were measured at the porewater velocity of the denitrification experiments. The numbers in brackets denote the range for denitrification experiments (2 technical replicates), standard deviation of residuals for oxygen respiration, standard error for cell counts and standard deviation for nitrate- nitrate production.
Back to article page