Int. J. Mol. Sci. 2013, 14, 1-x manuscripts; doi:10.3390/ijms140x000x International Journal of Molecular Sciences ISSN 1422-0067 www.mdpi.com/journal/ijms Type of the Paper (Article, Review, Communication, etc.) Mechanisms of Adaptation and Tolerance in Aspergillus niger UCP/WFCC 1261 by Copper-induced to Oxidative Response Marcos A. Cavalcanti Luna 1,3 , Cristiane Cidália S. Cordeiro 1,3 , Edson Rodrigues Vieira 1,3 , Maria Helena M. Estevam Alves 1,3 , José Henrique E. S. Freitas 2,3 , Kaoru Okada 3 , Galba Maria Campos Takaki 3 *, Aline Elesbão do Nascimento 3 1 Master Course in Development of Environmental Processes, Catholic University of Pernambuco, 50.050-900 Recife - PE, Brazil. E.mails: macluna@yahoo.com.br (M.A.C.L.); cidalia@hotmail.com (C.C.S.C.); edsonipubi@gmail.com (E.R.V.); maria@helena.bio.br (M.H.M.E.A.) 2 Biology student, Catholic University of Pernambuco, 50.050-900 Recife - PE, Brazil. E. mail: henrikky17@gmail.com (J.H.E.S.F.) 3 Nucleus of Research in Environmental Sciences, Catholic University of Pernambuco, 50.050-590 Recife - PE, Brazil. E.mails: kao@unicap.br (K.O.); galba_takaki@yahoo.com.br (G.M.C.T.); elesbao@unicap.br (A.E.N.) † These authors contributed equally to this work. * Author to whom correspondence should be addressed; E-Mail: galba_takaki@yahoo.com.br (G.M.C.T.); Tel.: +55-81-2119-4017 ; Fax: +55-81-2119-4043. Received: / Accepted: / Published: Abstract: The effects of copper exposure, during growth, on the biomass production, total protein, catalase, gluthation S transferase, gluthation peroxidase, peroxidase, polyphosphate, acid and alkaline phosphatases, ultrastructure and ability to remove the metal of Aspergillus niger, obtained from caatinga soil were evaluated. All parameters tested were influenced by the initial metal concentration in culture medium. The metal presence induced high levels of antioxidant enzymes, including lipid peroxidation, revealing the appearance of oxidative stress response. The variation in polyphosphate levels indicate the polymer participation in response to stress induced by copper. The activities of the phosphatases were positively influenced by growing in the presence of copper sulfate. Ultrastructural changes in cell surface, electron density, thickness, and septation were visualized in cells exposed in crescent metal concentrations. The isolate was able to remove the agent from the growth medium, maintaining its physiological functions. The results indicate that the isolate was able to grow in high concentrations of copper sulfate, activating mechanisms for adaptation and tolerance in presence of metal, and a high efficiency to remove the agent. Such data are fundamentals to understanding the OPEN ACCESS