TY - JOUR
T1 - Stress response of Chlorella pyrenoidosa to nitro-aromatic compounds
AU - Xu, Chang
AU - Wang, Ruihua
AU - Zhang, Y. F.
AU - Cheng, P.
AU - Choi, Martin M.F.
AU - Poon, Karen
N1 - Publisher Copyright:
© 2014, Springer-Verlag Berlin Heidelberg.
PY - 2015/3
Y1 - 2015/3
N2 - Handling of two nitro-aromatic compounds, 4-nitroaniline (4NA) and 4-nitrophenol (4NP), simultaneously by Chlorella pyrenoidosa was investigated. Algae would secrete or degrade nitro-aromatic compounds depending on different environmental conditions, in which the mode of handling was determined by the relative formation and degradation rate of the compound. Repeated intermittent trigger with externally added 4NA would induce the continuous secretion of 4NA by algae. Simultaneous exposure of both 4NA and 4NP to algae at normal condition would induce the algae to secrete both compounds. An increase in 4NA exposure concentration would elevate both 4NA and 4NP secretion, and that would be inhibited by the stress conditions of starving or lack of oxygen. Increased 4NA degradation per production rate induced by starving or lack of oxygen might explain the subsequent decrease in 4NA secretion in the presence of 4NP in algae. For 4NP in the presence of 4NA, secretion at normal condition was completely stopped and turned to degradation mode in stress conditions. The decreased formation and increased degradation of 4NP during starving for replenishing energy would explain the net degradation of 4NP in starving condition. The condition of lack of oxygen would inhibit the 4NP formation from 4NA via oxidative deamination, while the degradation of 4NP might not be significantly affected because alternative pathway of degradation via nitro-reduction was available. It may lead to the degradation rate exceeding the formation and explain the net degradation of 4NP in the condition of lack of oxygen.
AB - Handling of two nitro-aromatic compounds, 4-nitroaniline (4NA) and 4-nitrophenol (4NP), simultaneously by Chlorella pyrenoidosa was investigated. Algae would secrete or degrade nitro-aromatic compounds depending on different environmental conditions, in which the mode of handling was determined by the relative formation and degradation rate of the compound. Repeated intermittent trigger with externally added 4NA would induce the continuous secretion of 4NA by algae. Simultaneous exposure of both 4NA and 4NP to algae at normal condition would induce the algae to secrete both compounds. An increase in 4NA exposure concentration would elevate both 4NA and 4NP secretion, and that would be inhibited by the stress conditions of starving or lack of oxygen. Increased 4NA degradation per production rate induced by starving or lack of oxygen might explain the subsequent decrease in 4NA secretion in the presence of 4NP in algae. For 4NP in the presence of 4NA, secretion at normal condition was completely stopped and turned to degradation mode in stress conditions. The decreased formation and increased degradation of 4NP during starving for replenishing energy would explain the net degradation of 4NP in starving condition. The condition of lack of oxygen would inhibit the 4NP formation from 4NA via oxidative deamination, while the degradation of 4NP might not be significantly affected because alternative pathway of degradation via nitro-reduction was available. It may lead to the degradation rate exceeding the formation and explain the net degradation of 4NP in the condition of lack of oxygen.
KW - 4-Nitroaniline
KW - 4-Nitrophenol
KW - Chlorella pyrenoidosa
KW - Secondary metabolites
KW - Stress response
UR - http://www.scopus.com/inward/record.url?scp=84925487892&partnerID=8YFLogxK
U2 - 10.1007/s11356-014-3582-4
DO - 10.1007/s11356-014-3582-4
M3 - Journal article
C2 - 25266057
AN - SCOPUS:84925487892
SN - 0944-1344
VL - 22
SP - 3784
EP - 3793
JO - Environmental Science and Pollution Research
JF - Environmental Science and Pollution Research
IS - 5
ER -