Afd. Vasconcelos et al., Optimization of laccase production by Botryosphaeria sp in the presence ofveratryl alcohol by the response-surface method, PROCESS BIO, 35(10), 2000, pp. 1131-1138
Botryosphaeria sp. produced two laccases (PPO-I and PPO-II) constitutively,
whose titers were enhanced by veratryl alcohol. The effect of veratryl alc
ohol and yeast extract concentration, time of cultivation and agitation spe
ed were evaluated by factorial analysis to select variables for optimizing
the production of laccases. Maximal laccase production was determined using
a second-order central-composite design and analyzed by the response-surfa
ce method. Veratryl alcohol concentration and time of cultivation were the
main factors increasing laccase production, while yeast extract had no infl
uence within the range 0.2-2.0% w/v. Response-surface analysis showed that
30.4 mM veratryl alcohol, for 4.5 days at 28 degrees C and 180 rpm, were th
e optimal conditions to maximize PPO-I production, while conditions for max
imal PPO-II production occurred within a range of 28-35 mM veratryl alcohol
over a growth period of 4-5.5 days. The model predicted 5.6 U ml(-1) for P
PO-I, and 0.6-1.0 U ml(-1) for PPO-II, which agreed with the experimentally
observed results. (C) 2000 Elsevier Science Ltd. All rights reserved.