Table 2 The effect of cell densities upon conversion values in ammonia elimination reactions.

From: The production of l- and d-phenylalanines using engineered phenylalanine ammonia lyases from Petroselinum crispum

Substrate (2 mM)

Cell density (OD600)/biocatalyst: substrate ratio (OD600:mM)

c (%)

eeD-1 (%)

eetheorD-1 (%)

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1/1:2

38.1a

63.3

61.7

2/1:1

39.9a

66.3

66.5

4/2:1

~50a

94.1

>99

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1/1:2

27.3b

37.5

37.5

2/1:1

45.6b

88.8

84.0

4/2:1

~50b

>99

>99

  1. aafter 24 h; bafter 5 h; eetheor – theoretical enantiomeric excess, calculated by the formula: \(\frac{c}{100-c}\times 100\); where c represents the experimentally determined conversion (%); Reaction conditions: assays were performed in 1.5 mL polypropylene tubes at 30 °C, 200 rpm, in 500 µL reaction volume, using 2 mM substrate concentration, different ratio of cell density (OD600)/substrate concentration (mM) and Tris buffer, pH 8.8 as reaction medium.
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