AMB Express This Provisional PDF corresponds to the article as it appeared upon acceptance Fully formatted PDF and full text (HTML) versions will be made available soon Recombinant bromelain production in Escherichia coli: Process optimization in shake flask culture by Response Surface Methodology AMB Express 2012, 2:12 doi:10.1186/2191-0855-2-12 Bala Muntari (balamukhtar@yahoo.com) Azura Amid (azuraamid@iium.edu.my) Maizirwan Mel (maizirwan@iium.edu.my) Mohammed S Jami (saedi@iium.edu.my) Hamzah M Salleh (hamzah@iium.edu.my) ISSN Article type 2191-0855 Original Submission date 21 November 2011 Acceptance date 15 February 2012 Publication date 15 February 2012 Article URL http://www.amb-express.com/content/2/1/12 This peer-reviewed article was published immediately upon acceptance It can be downloaded, printed and distributed freely for any purposes (see copyright notice below) Articles in AMB Express are listed in PubMed and archived at PubMed Central For information about publishing your research in AMB Express go to http://www.amb-express.com/authors/instructions/ For information about other SpringerOpen publications go to http://www.springeropen.com © 2012 Muntari et al ; licensee Springer This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited Recombinant bromelain production in Escherichia coli: Process optimization in shake flask culture by Response Surface Methodology Bala Muntaria,b , Azura Amida, Maizirwan Mela, Mohammed S Jamia and Hamzah M Salleha* a Bioprocess and Molecular Engineering Research Unit, Department of Biotechnology Engineering, Faculty of Engineering, International Islamic University Malaysia, P.O Box 10, 50728, Kuala Lumpur, Malaysia b Department of Biochemistry, Faculty of Science, Bayero University, Kano P.M.B 3011, Kano, Nigeria BM: balamukhtar@yahoo.com AA: azuraamid@iium.edu.my MM: maizirwan@iium.edu.my MSJ: saedi@iium.edu.my HMS: hamzah@iium.edu.my ∗ Corresponding author: Tel.: +60361964426, Fax: + 60361964442 Email address: hamzah@iium.edu.my Abstract Bromelain, a cysteine protease with various therapeutic and industrial applications, was expressed in Escherichia coli, BL21-AI clone, under different cultivation conditions (post-induction temperature, L-arabinose concentration and post-induction period) The optimized conditions by response surface methodology using face centered central composite design were 0.2 % (w/v) L-arabinose, hr and 25 ºC The analysis of variance coupled with larger value of R2 (0.989) showed that the quadratic model used for the prediction was highly significant (p