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. Author manuscript; available in PMC: 2006 May 2.
Published in final edited form as: Environ Toxicol Chem. 2006 Apr;25(4):973–984. doi: 10.1897/05-334r.1

Table 3.

Efficacy of lyophilized esterase on removal of bifenthrin-associated toxicity to Ceriodaphnia dubiaa

48-h Mortality (%)
Esterasec
 Bovine serum albumind
Bifenthrin (ng/L)b 0xe 10x 50x 100x 250x 10x 50x 100x 250x
0 0 0 0 0 0 5 ± 10 0 0 0
300 100 0 0 0 0 100 100 100 30 ± 20
450 100 100 0 0 0 100 100 100 100
600 100 100 0 0 0 100 100 100 100
a

Data are the average of four replicates with five neonates ± standard deviation. Studies were performed in laboratory water amended to U.S. Environmental Protection Agency moderately hard specifications.

b

Bifenthrin concentrations are nominal water concentrations.

c

Esterase was prepared as described in Materials and Methods using lyophilized esterase (lot 039H7005; Sigma Chemical, St. Louis, MO, USA).

d

Bovine serum albumin (BSA) was added at protein concentrations equivalent to those used in the esterase preparations (250x BSA = 3.125 mg protein/ml).

e

1x dilution = 2.3 × 10−3 U/ml. A unit of activity is the amount of enzyme that hydrolyzes 1.0 μmol of butyrate to butyric acid and ethanol per minute at pH 8.0 at 25°C (as defined by Sigma Chemical).