GENOMICS, TRANSCRIPTOMICS, PROTEOMICS Differential proteomic analysis of an engineered Streptomyces coelicolor strain reveals metabolic pathways supporting growth on n-hexadecane Giuseppe Gallo & Luca Lo Piccolo & Giovanni Renzone & Ruggero La Rosa & Andrea Scaloni & Paola Quatrini & Anna Maria Puglia Received: 18 January 2012 / Revised: 16 March 2012 / Accepted: 19 March 2012 / Published online: 13 April 2012 # Springer-Verlag 2012 Abstract The alkB gene, encoding an alkane monooxyge- nase in the actinomycete Gordonia sp. SoCg, was expressed in the non-alkane-degrading actinomycete Streptomyces coeli- color M145. The resulting engineered strain, M145-AH, can grow on n-hexadecane as sole carbon source. To unravel proteins associated with growth on n-alkanes, proteome of M145-AH after 6, 24, and 48 h of incubation in the Bushnell- Haas (BH) mineral medium containing n-hexadecane as sole carbon source (H condition) and in BH without any carbon source (0 condition) were compared using 2D-differential gel electrophoresis. Proteome analysis revealed significant changes only at 48 h, showing 48 differentially abundant proteins identified by mass spectrometry procedures. To asses if these proteins were specifically related to n-hexadecane metabolism, their expression was investigated, comparing H proteome with that of M145-AH incubated in BH with glucose as sole carbon source (G condition). Thus, protein expression profiles at 6, 24, and 48 h under H, 0, and G conditions were combined, revealing that M145-AH regulates in a temporally- and carbon source-dependent manner the expression of pro- teins involved in regulatory events, central carbon metabolism, respiration, β-oxidation, membrane transport, and amino acid and protein metabolism. Interestingly, 21 % of them, mostly involved in membrane transport and protein metabolism, showed a n-hexadecane-dependent regulation with regulatory proteins such as CRP likely to have a key role in M145-AH n- hexadecane growth. These results, expanding the knowledge on n-alkane utilization in Gram-positive bacteria, reveal genes to be targeted to develop an efficient S. coelicolor M145-AH- based bioremediation system. Keywords n-hexadecane utilization . n-alkane monoxygenase . Streptomyces . Engineered strain . 2D-DIGE analysis . Proteomics Introduction Natural n-alkanes are saturated linear hydrocarbons whose chain length varies from one (methane) to more than 50 carbon atoms. They constitute up to 50 % of the crude oil, but living organisms, such as bacteria, green algae, plants, and some animals, also produce them. Thus, n-alkanes are widespread at low concentrations in most soil and water environments. Many microorganisms can degrade n-alkanes, using them as a source of carbon and energy (van Beilen et al. 2002; Wentzel et al. 2007). Soil, ocean sediments, or sand contain a fair amount of hydrocarbon-degrading bacteria, whose num- ber increases in oil-polluted sites (Lu et al. 2011; Yakimov et al. 2007). Alkane-degrading bacteria generally have a versatile metabolism that allows them to use many other compounds as Giuseppe Gallo and Luca Lo Piccolo contributed equally to this work. Electronic supplementary material The online version of this article (doi:10.1007/s00253-012-4046-8) contains supplementary material, which is available to authorized users. G. Gallo (*) : L. Lo Piccolo (*) : R. La Rosa : P. Quatrini : A. M. Puglia Dipartimento di Scienze e Tecnologie Molecolari e Biomolecolari (STEMBIO), University of Palermo V.le delle Scienze, Ed. 16, 90128 Palermo, Italy e-mail: giuseppe.gallo@unipa.it e-mail: lucalopiccolo@gmail.com G. Renzone : A. Scaloni Proteomics & Mass Spectrometry Laboratory, ISPAAM, National Research Council, 80147 Naples, Italy Appl Microbiol Biotechnol (2012) 94:1289–1301 DOI 10.1007/s00253-012-4046-8