Newsletter | October 15, 2026

10.15.26 -- Strain Engineering For Protein Production

Improving Scale-Up Starts With Expression Strategy

Identifying expression challenges early in recombinant protein development, before scale-up begins, reduces wasted resources and supports more confident go/no-go decisions. Microbial screening and strain-engineering strategies can surface yield, solubility, and scalability risks at a stage when they are still manageable.

 

Fab Antibody Fragment Titer Improvement

A systematic strain screening approach across 800 candidates and 160 expression plasmid combinations resolved a low-titer Fab fragment challenge, producing over 4 g/L of active, assembled Fab at 2L fermentation scale.

 

Overcoming ncAA Production Bottlenecks: High-Titer Antibody Expression With 100% pAzF Incorporation At Scale And Minimal Host Toxicity

Learn how rational design and optimized feed strategies achieve high-titer protein expression and full non-canonical amino acid incorporation at scale, overcoming common toxicity and production yield bottlenecks.

 

Extracellular Protein Secretion: A Lever In Microbial Expression

Extracellular secretion into culture media eliminates lysis and its associated impurity burden. Examine proof-of-principle data showing engineered hosts localizing diverse proteins—antibody derivatives, enzymes, toxins—into cell-free broth with confirmed molecular integrity across 96-well screens.

 

Rapid Assessment Of Fab-VHH Expression: Application Of The Pfast™ Program For Early-Stage Titer And Activity Screening

Using a pooled expression screening approach across 40 vector configurations, researchers identified light chain-first gene orientation as optimal for a bi-specific antibody fragment fusion, yielding up to 570 µg/mL soluble, active construct within 10 days.

 

SOLUTIONS

What Our Partners Achieve With Pfenex Expression Technology

When E. coli, CHO, and yeast fall short on titer, protein quality, or scalability, a P. fluorescens-based expression platform built on 25 years of strain engineering offers a different path.