Biosynthesis of Polyhydroxyalkanoates From Sucrose by Recombinant Pseudomonas putida KT2440

Abstract A sucrose‐utilization pathway was developed in Pseudomonas putida using sacC from Mannheimia succiniciproducens , which encodes a β‐fructofuranosidase that hydrolyzes sucrose into glucose and fructose. Excretion of β‐fructofuranosidase into the culture medium was confirmed via western blot analysis. In nitrogen‐limited cultivation, P. putida expressing SacC produced 10.52 wt % medium‐chain‐length polyhydroxyalkanoate (MCL‐PHA), while P. putida expressing SacC along with poly(3‐hydroxybutyrate) [P(3HB)] biosynthesis genes produced 9.16 wt % P(3HB) from sucrose. Batch and fed‐batch cultures of recombinant P. putida suggested that the glucose and fructose derived from sucrose can be completely utilized for cell growth and P(3HB) production. In fed‐batch cultures, sucrose supplied into the fermentor to maintain its concentration around 20 g/L was rapidly hydrolyzed into glucose and fructose supporting the production of 30.2 g/L P(3HB) with 38.1 wt %. The engineered P. putida reported herein can facilitate the production of PHAs from sucrose, an abundant and inexpensive carbon source.