Ma. Nasr et al., Effects of culture conditions on enhancement of 2,4-dinitrotoluene degradation by Burkholderia engineered with the Vitreoscilla hemoglobin gene, BIOTECH PR, 17(2), 2001, pp. 359-361
Growth and degradation of 2,4-dinitrotoluene (2,4-DNT) were compared in liq
uid cultures in shake flasks for Burkholderia sp. strain DNT and strain DNT
engineered to produce Vitreoscilla (bacterial) hemoglobin (strain Wi). Par
ameters varied included aeration rate, initial 2,4-DNT concentration (50 an
d 200 ppm!, and concentration and type of cosubstrate (yeast extract, succi
nate, casamino acids, and tryptic soy broth). 2,4-DNT degradation increased
with increasing cosubstrate concentration and was greater for strain WI th
an strain DNT under most conditions tested; the greatest advantages of YV1
(up to 3.5-fold) occurred under limited aeration. A third strain (YV1m), de
rived from YV1 by repeated growth on 2,4-DNT-containing medium, demonstrate
d increased 2,4-DNT degradation (up to 1.3-fold compared to YV1) at 200 ppm
2,4-DNT. The growth profiles of the three strains with respect to each oth
er were in general similar to those of the degradation patterns of 2,4-DNT.