BIOTECHNOLOGICALLY RELEVANT ENZYMES AND PROTEINS Comparison of transplastomic Chlamydomonas reinhardtii and Nicotiana tabacum expression system for the production of a bacterial endoglucanase Matteo Faè 1 & Sonia Accossato 1,2 & Rino Cella 1 & Fabrizia Fontana 3 & Michel Goldschmidt-Clermont 3 & Sadhu Leelavathi 4 & Vanga Siva Reddy 4 & Paolo Longoni 3 Received: 6 December 2016 /Revised: 23 January 2017 /Accepted: 27 January 2017 # Springer-Verlag Berlin Heidelberg 2017 Abstract The bulk production of recombinant enzymes by either prokaryotic or eukaryotic organisms might contribute to replace environmentally non-friendly chemistry-based in- dustrial processes with enzyme-based biocatalysis, provided the cost of enzyme production is low. In this context, it is worth noting that the production of recombinant proteins by photosynthetic organisms offer both eukaryotic (nuclear) and prokaryotic (chloroplast) alternatives, along with the advan- tage of an autotrophic nutrition. Compared to nuclear trans- formation, chloroplast transformation generally allows a higher level of accumulation of the recombinant protein of interest. Furthermore, among the photosynthetic organisms, there is a choice of using either multicellular or unicellular ones. Tobacco, being a non-food and non-feed plant, has been considered as a good choice for producing enzymes with ap- plications in technical industry, using a transplastomic ap- proach. Also, unicellular green algae, in particular Chlamydomonas reinhardtii, have been proposed as candidate organisms for the production of recombinant proteins. In the light of the different features of these two transplastomic sys- tems, we decided to make a direct comparison of the efficien- cy of production of a bacterial endoglucanase. With respect to the amount obtained, 14 mg g -1 of biomass fresh weight equivalent to 8–10% of the total protein content and estimated production cost, 1.5–2€ kg -1 , tobacco proved to be far more favorable for bulk enzyme production when compared to C. reinhardtii which accumulated this endoglucanase at 0.003% of the total protein. Keywords Chlamydomonas reinhardtii . Tobacco . Chloroplast . Cellulase . Molecular farming Introduction Recombinant DNA technology offers a unique opportunity to produce proteins of commercial interest that can meet the needs of the industrial, medical, and pharmaceutical sectors. For many years, the production of recombinant proteins by either prokaryotic or eukaryotic organisms has been a reality, and advantages and disadvantages of both systems has been evalu- ated in depth (Houdebine 2009; Demain and Vaishnav 2009; Surzycki et al. 2009; Hacker et al. 2009; Fernández-Robledo and Vasta 2010; Potvin and Zhang 2010). Remarkably, plant organisms offer both eukaryotic (nuclear) and prokaryotic (chloroplast) expression systems and have been proven to be suitable for the production of antibodies, enzymes, and vac- cines (Leelavathi et al. 2003; Daniell et al. 2009; Verma et al. 2010; Scotti et al. 2012; Pantaleoni et al. 2014; Longoni et al. 2015; Jin and Daniell 2015). Compared to nuclear transforma- tion, chloroplast transformation typically allows a higher accu- mulation of the protein of interest, which, for certain Electronic supplementary material The online version of this article (doi:10.1007/s00253-017-8164-1) contains supplementary material, which is available to authorized users. * Paolo Longoni paolo.longoni@unige.ch 1 Department of Biology and Biotechnology, University of Pavia, Via Ferrata 9, 27100 Pavia, Italy 2 Present address: Laboratory of Plant Physiology, University of Neuchâtel, Rue Emilie-Argand 11, CH-2000 Neuchâtel, Switzerland 3 Department of Botany and Plant Biology, University of Geneva, 30 Quai Ernest Ansermet, Sciences III, CH-1211 Genève, Switzerland 4 Plant Transformation Group, International Center for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India Appl Microbiol Biotechnol DOI 10.1007/s00253-017-8164-1