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Todays Biochemical Engineer may contribute to advances in a wide range of technical areas. The recent Biochemical and Molecular Engineering XXI conference focused on The Next Generation of Biochemical and Molecular Engineering: The role of emerging technologies in tomorrows products and processes. On the basis of topical discussions at this conference, this perspective synthesizes one vision on where investment in research areas is needed for biotechnology to continue contributing to some of the worlds grand challenges.

The N-acylhomoserine lactone (AHL) receptor SpnR is a LuxR family protein that acts as a negative regulator of AHL-dependent quorum sensing (QS). SpnR binds to DNA in Serratia marcescens AS-1 via the spn box; however, the binding affinity of SpnR with the nucleotides on the spn box has not yet been investigated. In this study, we used an spn-box-modified sensor electrode, and quartz crystal microbalance analysis demonstrated a drastic reduction of the uptake of SpnR. The nucleotides G5 and C16 at the AHL-receptor complex-binding site are conserved in Gram-negative bacteria, including the lux box in Vibrio fischeri, the tra box in Agrobacterium tumefaciens, and the spn box in S. marcescens. Indeed, the affinity of SpnR to DNA was reduced to 8% by G5C substitution of the spn box. The affinity of SpnR tagged with maltose-binding protein to the immobilized gene promoter was reduced in the order of C16G and G5C substitutions, which corresponded with previous reports on the lux box. These results suggest that formation of hydrogen bonds at amino acid residues containing guanine at position 5 on a lux-box-like promoter universally contributes to the stability of the receptor complex, whose interaction initiates a sequential QS process in the LuxR family. Biotechnol. Bioeng. 2016;113: 2513-2517. © 2016 Wiley Periodicals, Inc., (© 2016 Wiley Periodicals, Inc.)

Modularization of a peptide antigen for presentation on a microbially synthesized murine polyomavirus (MuPyV) virus-like particle (VLP) offers a new alternative for rapid and low-cost vaccine delivery at a global scale. In this approach, heterologous modules containing peptide antigenic elements are fused to and displayed on the VLP carrier, allowing enhancement of peptide immunogenicity via ordered and densely repeated presentation of the modules. This study addresses two key engineering questions pertaining to this platform, exploring the effects of (i) pre-existing carrier-specific immunity on modular VLP vaccine effectiveness and (ii) increase in the antigenic element number per VLP on peptide-specific immune response. These effects were studied in a mouse model and with modular MuPyV VLPs presenting a group A streptococcus (GAS) peptide antigen, J8i. The data presented here demonstrate that immunization with a modular VLP could induce high levels of J8i-specific antibodies despite a strong pre-existing anti-carrier immune response. Doubling of the J8i antigenic element number per VLP did not enhance J8i immunogenicity at a constant peptide dose. However, the strategy, when used in conjunction with increased VLP dose, could effectively increase the peptide dose up to 10-fold, leading to a significantly higher J8i-specific antibody titer. This study further supports feasibility of the MuPyV modular VLP vaccine platform by showing that, in the absence of adjuvant, modularized GAS antigenic peptide at a dose as low as 150 ng was sufficient to raise a high level of peptide-specific IgGs indicative of bactericidal activity., (Copyright © 2013 Wiley Periodicals, Inc.)