A consortium-based approach to adaptive laboratory evolution of Acinetobacter baylyi ADP1 reveals novel genetic targets for lignin valorization

Journal of Applied Microbiology, vol. 136

Abstract

AIM: This study focuses on a novel process for the adaptive laboratory evolution (ALE) of Acinetobacter baylyi ADP1 to enable simultaneous utilization of multiple lignin-related aromatics (LRAs). The genomes of the evolved strains were sequenced and compared with the wild type for identification of genetic targets for reverse engineering. METHODS AND RESULTS: In the first step of the two-step ALE process, different A. baylyi ADP1 strains were evolved to grow on high concentrations of individual LRAs. In the second step, a consortium of these single-LRA evolved strains were grown and further evolved on a mixture of LRAs, which resulted in a unique strain (A. baylyi SAG_185). Whole-genome sequence (WGS) analysis of all the evolved strains revealed large-scale mutations involving insertion sequences. CONCLUSION: Acinetobacter baylyi SAG_185 could simultaneously utilize multiple LRAs at higher concentrations (85 mmol l-1) as well as grow on depolymerized lignin. WGS analysis of the evolved strains obtained from ALE revealed potential genetic targets for reverse engineering of A. baylyi ADP1 for lignin valorization. In particular, A. baylyi SAG_185 revealed a critical mutation in the vanR repressor gene, resulting in the up-regulation of vanAB genes which are required to convert vanillate to the key intermediate, protocatechuate.

Authors 6

1. Suchismita Maiti Aachen Institute of Applied Microbiology

   Indian Institute of Technology Madras · RWTH Aachen University

   Affiliation as printed

   Indian Institute of Technology Madras Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, , Chennai, Tamil Nadu 600036 ,

   Institute of Applied Microbiology, RWTH Aachen University , Worringerweg 1, 52074 Aachen ,

   Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, Tamil Nadu 600036, India

   Institute of Applied Microbiology, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany

2. Prashant Singh

   Indian Institute of Technology Madras

   Affiliation as printed

   Indian Institute of Technology Madras Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, , Chennai, Tamil Nadu 600036 ,

   Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, Tamil Nadu 600036, India

3. Vishnu Prasad J.

   Indian Institute of Technology Madras

   Affiliation as printed

   Indian Institute of Technology Madras Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, , Chennai, Tamil Nadu 600036 ,

   Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, Tamil Nadu 600036, India

4. Anantha-Barathi Muthukrishnan corresponding

   Indian Institute of Technology Madras

   Affiliation as printed

   Indian Institute of Technology Madras Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, , Chennai, Tamil Nadu 600036 ,

   Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, Tamil Nadu 600036, India

5. Lars M. Blank corresponding Aachen Institute of Applied Microbiology

   RWTH Aachen University

   Affiliation as printed

   Institute of Applied Microbiology, RWTH Aachen University , Worringerweg 1, 52074 Aachen ,

   Institute of Applied Microbiology, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany

6. Guhan Jayaraman corresponding

   Indian Institute of Technology Madras

   Affiliation as printed

   Indian Institute of Technology Madras Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, , Chennai, Tamil Nadu 600036 ,

   Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, Tamil Nadu 600036, India