Fed-batch strategies using butyrate for high cell density cultivation of Pseudomonas putida and its use as a biocatalyst

Abstract

A mathematically based fed-batch bioprocess demonstrated the suitability of using a relatively cheap and renewable substrate (butyric acid) for Pseudomonas putida CA-3 high cell density cultivation. Butyric acid fine-tuned addition is critical to extend the fermentation run and avoid oxygen consumption while maximising the biomass volumetric productivity. A conservative submaximal growth rate (μ of 0.25 h(-1)) achieved 71.3 g L(-1) of biomass after 42 h of fed-batch growth. When a more ambitious feed rate was supplied in order to match a μ of 0.35 h(-1), the volumetric productivity was increased to 2.0 g L(-1) h(-1), corresponding to a run of 25 h and 50 g L(-1) of biomass. Both results represent the highest biomass and the best biomass volumetric productivity with butyrate as a sole carbon source. However, medium chain length polyhydroxyalkanoate (mcl-PHA) accumulation with butyrate grown cells is low (4 %). To achieve a higher mcl-PHA volumetric productivity, decanoate was supplied to butyrate grown cells. This strategy resulted in a PHA volumetric productivity of 4.57 g L(-1) h(-1) in the PHA production phase and 1.63 g L(-1) h(-1)over the lifetime of the fermentation, with a maximum mcl-PHA accumulation of 65 % of the cell dry weight.

Bioreactor Operating Strategies for Improved Polyhydroxyalkanoate (PHA) Productivity

“…When nonanoic acid was co-fed with glucose (1:1 mass basis) at an exponential growth rate (μ = 0.25 h −1 ) followed by linear feeding, a very similar Q v was obtained, but the yield of PHA from nonanoic acid improved from 0.60 g g −1 to as much as 0.69 g g −1 [56]. Similar strategies have been applied by others [59,60,61,62,63].…”

“…These include the use of high-purity carbon substrates as well as using O 2 -enriched air for aeration. More recently, there appears to be somewhat of a shift toward PHA production from waste substrates such as crude glycerol [90,99], plant-based oils [77,79,94,95,102], and lignocellulose-based hydrolysates [98], and devising strategies to achieve HCD cultures without use of purified O 2 streams [61,62,103].…”

Rheological Behavior of High Cell Density Pseudomonas putida LS46 Cultures during Production of Medium Chain Length Polyhydroxyalkanoate (PHA) Polymers

“…Considering that other fed-batch strategies have achieved 100 g•L −1 CDM or more in PHA production [11,13,77,78], the reduction in K L a over time could be considerably more significant in those systems compared to that described in this work. This may often be neglected in bench-scale HCD PHA cultivations in which stirring and aeration are typically set as high as is realistically possible to maximize productivity.…”

High-level fed-batch fermentative expression of an engineered Staphylococcal protein A based ligand in E. coli: purification and characterization

“…Batch processes are suitable for small productions and the equipment is relatively simple compared to other processes. However, reaction conditions changes with time causing problems in precise fermentation processes, but on the other hand provide high production and a better quality product for continuous processes due to constant conditions (Shpigel et al 2000 ; Yee and Blanch 1992 ; Cerrone et al 2014 ; Ibrahim and Steinbuchel 2010 ). Batch processes are more useful for kinetic studies, and require flow control in order to maintain constant conditions (Shiloach and Fass 2005 ).…”