| Institution: | 1. Key Laboratory of Industrial Fermentation Microbiology, Tianjin University of Science & Technology, Ministry of Education, Tianjin 300457, China;2. Key Laboratory of Shandong Microbial Engineering, QILU University of Technology, Jinan 250353, Shandong, China;1. Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India;2. Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, UK;3. DBT-Pan IIT Center for Bioenergy, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India;4. Wadhwani Research Center for Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India;1. Molecular Microbial Physiology Group, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands;2. Photanol BV, Amsterdam, The Netherlands;1. Department of Chemistry, United Arab Emirates University, Al-Ain, United Arab Emirates;2. Genetics and Experimental Bioinformatics, Institute of Biology 3, Faculty of Biology, University of Freiburg, Germany;3. Freiburg Institute for Advanced Studies, University of Freiburg, Germany;1. Key Laboratory of Biofuels, No. 189 Songling Road, Qingdao, 266101, China;2. Shandong Provincial Key Laboratory of Energy Genetics, No. 189 Songling Road, Qingdao, 266101, China;3. Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, No. 189 Songling Road, Qingdao, 266101, China;4. Dalian National Laboratory for Clean Energy, Dalian, China;5. Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China |
| Abstract: | Trehalose is a non-reducing disaccharide with a wide range of applications in food, cosmetic, and pharmaceutical industries. Cyanobacteria are promising cell factories to produce biochemicals by using solar energy and CO2. Trehalose is biosynthesized at low intracellular concentrations as a salt-inducible compatible solute in some cyanobacteria. In the current study, we demonstrated the efficient trehalose production without salt induction in cyanobacteria by metabolic engineering. The trehalose transporter 1 (TRET1) from an anhydrobiotic insect (Polypedilum vanderplanki) was successfully expressed in the engineered strains and the intracellular trehalose was efficiently secreted to the medium. As the results, the engineered strain co-expressing maltooligosyl trehalose synthase (MTS), maltooligosyl trehalose trehalohydrolase (MTH) and TRET1 secreted 97% of trehalose to the medium, and the titer was up to 2.7 g/L in 15 days. In addition, 5.7 g/L trehalose was produced by semi-continuous cultivation in 34 days. Taken together, this work demonstrates cyanobacteria can be applied as cell factories for direct sunlight-driven conversion of CO2 into excreted trehalose. |
