Advancing Protein Display on Bacterial Spores through an Extensive Survey of Coat Components

The profound stability of bacterial spores makes them a promising platform for biotechnological applications like biocatalysis, bioremediation, drug delivery, etc. However, though the Bacillus subtilis spore is composed of >40 types of proteins, only ∼12 have been explored as fusion carriers for protein display. Here, we assessed the suitability of 33 spore proteins (SPs) as enzyme display carriers by direct allele tagging at native genomic loci. Of the 33 SPs investigated, 26 formed functional fusions with β-glucuronidase (GUS)─a ∼272 kDa homotetramer. This almost triples the number of SPs assessed for enzyme display and doubles the number of functional fusions documented in the literature. We quantitatively assessed 1) SP promoter activation dynamics, 2) GUS activity on spores, 3) surface availability, and 4) protection from thermal and proteolytic degradation. Multicopy expression and pairwise coexpression of the most promising SP-GUS fusions highlighted the complexity of spore structure/assembly and the difficulty in predicting compatibility between different SP fusions. We also assessed the suitability of engineered spores to degrade PET (polyethylene terephthalate) films and found that surface-exposed SPs were most effective. Beyond the broad survey, a key outcome of our work was the identification of SscA (small spore coat assembly protein A) as an effective spore display carrier. SscA supported enzyme activity at least 4-fold higher than any other SP, including the well-established anchor, CotY. We attribute this to its promoter, which demonstrated early and sustained activation relative to other SPs and its small size (∼3 kDa), which likely minimally interferes with enzyme folding, oligomerization, and activity. Labeling and genetic studies, its hydrophobic nature, and low surface availability suggest that SscA assembles within the inner spore coat, which makes it stabilizing and suitable for many biocatalytic applications. Overall, this work serves as a knowledge base to advance the biotechnological utility of B. subtilis spores.

pubs.acs.org

biorxiv.org

doi.org

Engineered antimicrobial-derived peptides to manipulate mixed microbial systems | Microbiology Spectrum

We demonstrate a novel approach for top-down manipulation of microbial co-cultures by leveraging the narrow-spectrum activity of a class IIa bacteriocin (bacterial-derived antimicrobial peptide). We e...

doi.org

Reversal of the Leloir pathway to promote galactose and tagatose synthesis from glucose

Love and Toomey et al. demonstrate a whole-cell process that converts glucose directly to the rare sugar D-tagatose by reversing the Leloir pathway. Structural and biochemical analyses reveal how a sp...

cell.com

Nikhil Nair - Tufts Rising Innovator of the Year

1 min 43 sec video

tuftsu.wistia.com

Meet Caravel: Pioneering a New Era of Biotechnology with the First Unified Platform for Protein Discovery and Delivery

/PRNewswire/ -- Caravel Bio, the first joint platform for protein discovery and delivery that enables new applications of synthetic biology, today announces...

prnewswire.com

Engineered antimicrobial-derived peptides to manipulate mixed microbial systems

Due to complexity of microbial communities and coarseness of currently available manipulation techniques (e.g. transplantation, antibiotic-treatment), it is often difficult to fully elucidate the inte...

biorxiv.org

High throughput screening of eukaryotic release factor 1 variants to enhance noncanonical amino acid incorporation

Noncanonical amino acids (ncAAs) enable diversification of protein functions, but the efficiency of genetic code expansion (GCE) in eukaryotes is hindered by competition between suppressor tRNAs and r...

biorxiv.org

Tufts Will Be Tuition-Free for U.S. Families Earning Less Than $150,000

Tufts University announces that U.S. students from families earning less than $150,000 will not have to pay undergraduate tuition.

now.tufts.edu

Working Toward Reducing Chemical Industry Dependence on Petroleum

Tufts researchers receive up to $4.5 million from DARPA to create robust, flexible biosynthetic manufacturing

now.tufts.edu

A Novel Phosphatase Reverses the Leloir Pathway to Promote Tagatose Synthesis from Glucose

D-Tagatose is a natural, low-calorie, rare monosaccharide that has gained substantial interest as an alternative sweetener. It offers numerous benefits, including a low glycemic index, prebiotic prope...

biorxiv.org

Here are the nearly 2,500 medical research grants canceled or delayed by Trump

Some cuts have been starkly visible, but the country’s medical grant-making machinery has also radically transformed outside the public eye.

nytimes.com

Tufts says federal authorities detained graduate student

The university received reports that an international graduate student was taken into custody from an off-campus apartment Tuesday night, President Sunil Kumar wrote in a letter to the school communit...

wbur.org

Design, Construction, and Validation of a Yeast-Displayed Chemically Expanded Antibody Library

In vitro display technologies, exemplified by phage and yeast display, have emerged as powerful platforms for antibody discovery and engineering. However, the identification of antibodies that disrupt...

pubs.acs.org

Five Tufts Faculty Named Senior Members of National Academy of Inventors

Tufts faculty newly named to the National Academy of Inventors have led to innovations in healing wounds, assessing health, treating rare disorders, and more

now.tufts.edu

Microbial lysates as low-cost serum replacements in cellular agriculture media formulation

Cultivated meat, the process of generating meat in vitro without sacrificing animals, is a promising alternative to the traditional practice of livest…

sciencedirect.com

biorxiv.org

biorxiv.org