Production of 3,4-dihydroxy L-phenylalanine by a newly isolated Aspergillus niger and parameter significance analysis by Plackett-Burman design

Table 1 Comparison of kinetic variables for propagation of A. niger GCBT-8 for L-dopa production

Kinetic variables	L-dopa production (mg/ml)
	Intact mycelia	Grinded mycelia
Product formation parameters
Q_p (mg/ml/min)	0.0029 ± 0.001^bc	0.0061 ± 0.003^a
Y_p/s (mg/mg)	0.875 ± 0.03^abc	0.905 ± 0.05^ab
q_p (mg/mg cells/min)	0.0012 ± 0.001^b	0.0024 ± 0.0003^a
Substrate consumption parameters
Q_s (mg/ml/min)	0.0033 ± 0.001^bcd	0.0067 ± 0.003^ab
q_s (mg/mg cells/min)	0.0002 ± 0.0001^bc	0.0003 ± 0.0001^ab
LSD	0.059	0.016
<p>	HS	S

Kinetic variables: Q_p (mg L-dopa produced/ml/min), Y_p/s (mg L-dopa produced/mg L-tyrosine consumed), q_p (mg L-dopa produced/mg cells used/min), Q_s (mg L-tyrosine consumed/ml/min), q_s (mg L-tyrosine consumed/mg cells used/min).
HS is for the 'highly significant' while S for 'significant' values. LSD is for least significant difference and <p> is for significance level in terms of probability. ± Indicates standard deviation among three parallel replicates. The values designated by different letters in each row differ significantly at p ≤ 0.05.

ISSN: 1472-6750