PRODUCTION AND HANDLING OF DEHALOCOCCOIDES BIOAUGMENTATION CULTURES - Bioaugmentation for Groundwater Remediation - page 108

2000 30

Load (kg)
Temperature (°C)

25

1500

20

1000 15

10

500

5

0 0

0 5 9 18 41 73 87 131 154 165 186 228 239

Time (min)

Figure 3.11. Membrane concentration of a 3,500-L SDC-9 TM culture using a ceramic membrane cell
concentration system. Cell concentration is monitored by using load cells to measure changes in
the weight of the reactor as water is removed. The culture is chilled during concentration to ensure
its viability.

Table 3.3. Effect of Storage Temperature on PCE Degradation Activity of SDC-9 TM

PCE Dechlorination Rate (mg/L h) a

4 C 13 C 22 C 28 C Time (days)

0 6.45 0.29 6.45 0.29 6.45 0.29 6.45 0.29

7 ND ND 1.20 0.11 0.33 0.10

14 7.30 0.13 4.10 0.57 ND ND

35 8.20 0.70 2.28 0.10 0.70 0.03 0.23 0.05

82 4.20 0.19 0.57 0.38 ND ND

a Values represent mean

SE of triplicate samples; ND - not determined

large volumes and high Dhc concentrations obtained during large-scale production, this loss
generally is insignificant relative to the benefits of cell concentration.

3.5.2 Culture Stability and Storage

Storage of bacterial cultures is critical for allowing timely delivery of cultures to con-
taminated sites, to coordinate culture injection with the availability of field personnel and
equipment (e.g., drilling rigs), and also to allow cultures to be injected over several days of
field-scale injection. To evaluate storage longevity, 10X-concentrated SDC-9 TM cultures were
incubated for up to 82 days at either 4 C, 13 Cor28 C in stainless steel containers. Periodically,
samples of the stored cultures were removed and assayed for their ability to degrade PCE
and cis -DCE. Activity of the culture decreased rapidly if stored at 13 or 28 C, but SDC-9 TM
could be stored at 4 C for > 35 days without loss of activity (Table 3.3 ). Cultures stored in this