Tolerance of arsenate-induced stress in Aspergillus niger, a possible candidate for bioremediation.
The arsenate tolerance limit in wild-type Aspergillus niger was determined. Because of its high tolerance, toxic effects of arsenate concentrations ranging from 25 to 100mg/L were investigated in regard to growth, intracellular thiols, proline and malondialdehyde (MDA) contents of wild-type A. niger. Cellular arsenate uptake was analyzed. Activities of catalase (CAT), superoxide dismutase (SOD), glutathione reductase (GR) and succinate dehydrogenase (SDH) were assayed. Growth of A. niger increased at 25mg/L arsenate, and it survived up to 100mg/L. MDA, intracellular thiol and proline contents increased up to a certain level. Activities of GR, SOD and CAT declined following a rise at low concentration(s); SDH activity decreased gradually with increased arsenate stress. Results indicated that A. niger had high arsenate uptake potential and could tolerate oxidative stress by manipulating its anti-oxidative defense mechanism, a property that may be exploited for removal of arsenate from contaminated aqua-environment.
Mukherjee
Abhishek
A
Department of Biochemistry and Biophysics, University of Kalyani, Kalyani 741235, India.
Das
Durba
D
Kumar Mondal
Sushil
S
Biswas
Raktim
R
Kumar Das
Tapan
T
Boujedaini
Naoual
N
Khuda-Bukhsh
Anisur R
AR
D001149:Arsenates / Q000633:toxicity*; D001234:Aspergillus niger / Q000187:drug effects* / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism; D001673:Biodegradation, Environmental; D002374:Catalase / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005980:Glutathione Reductase / Q000378:metabolism; D008315:Malondialdehyde / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects*; D011392:Proline / Q000378:metabolism; D012989:Soil Pollutants / Q000633:toxicity*; D013385:Succinate Dehydrogenase / Q000378:metabolism; D013438:Sulfhydryl Compounds / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000633:toxicity*
D001149:Arsenates; D012989:Soil Pollutants; D013438:Sulfhydryl Compounds; D014874:Water Pollutants, Chemical; D008315:Malondialdehyde; D011392:Proline; D002374:Catalase; D013482:Superoxide Dismutase; D013385:Succinate Dehydrogenase; D005980:Glutathione Reductase; C025657:arsenic acid