Biology subjects

Goosens, V. J.

Publications and source records attributed to Goosens, V. J..

4 recordsLinked to original sources

bioRxiv2023

Self-dyeing textiles grown from cellulose-producing bacteria with engineered tyrosinase expression

Environmental concerns are driving interests in post-petroleum synthetic textiles produced from microbial and fungal sources. Bacterial cellulose is a promising sustainable leather alternative, on account of its material properties, low infrastructure needs and biodegradability. However, for alternative textiles like bacterial cellulose to be fully sustainable, alternative ways to dye textiles need to be developed alongside alternative production methods. To address this, we here use genetic engineering of Komagataeibacter rhaeticus to create a bacterial strain that grows self-dyeing bacterial cellulose. Dark black pigmentation robust to material use is achieved through melanin biosynthesis in the bacteria from recombinant tyrosinase expression. Melanated bacterial cellulose production can be scaled up for the construction of prototype fashion products, and we illustrate the potential of combining engineered self-dyeing with tools from synthetic biology, via the optogenetic patterning of gene expression in cellulose-producing bacteria. With this work, we demonstrate that combining genetic engineering with current and future methods of textile biofabrication has the potential to create a new class of textiles.

synthetic biology↗

bioRxiv2021

Komagataeibacter tool kit (KTK): a modular cloning system for multigene constructs and programmed protein secretion from cellulose producing bacteria

Bacteria proficient at producing cellulose are an attractive synthetic biology host for the emerging field of Engineered Living Materials (ELMs). Species from the Komagataeibacter genus produce high yields of pure cellulose materials in a short time with minimal resources, and pioneering work has shown that genetic engineering in these strains is possible and can be used to modify the material and its production. To accelerate synthetic biology progress in these bacteria, we introduce here the Komagataeibacter tool kit (KTK), a standardised modular cloning system based on Golden Gate DNA assembly that allows DNA parts to be combined to build complex multigene constructs expressed in bacteria from plasmids. Working in Komagataeibacter rhaeticus, we describe basic parts for this system, including promoters, fusion tags and reporter proteins, before showcasing how the assembly system enables more complex designs. Specifically, we use KTK cloning to reformat the Escherichia coli curli amyloid fibre system for functional expression in K. rhaeticus, and go on to modify it as a system for programming protein secretion from the cellulose producing bacteria. With this toolkit, we aim to accelerate modular synthetic biology in these bacteria, and enable more rapid progress in the emerging ELMs community.

synthetic biology↗

bioRxiv2018

In depth biochemical and structural analysis of a Gram-positive type IV pilus

Type IV pili (Tfp) are functionally versatile filaments, widespread in prokaryotes, that belong to a large class of filamentous nanomachines known as type IV filaments (Tff). Although Tfp have been extensively studied in several Gram-negative pathogens where they function as key virulence factors, many aspects of their biology remain poorly understood. Here, we performed a global biochemical and structural analysis of Tfp in a recently emerged Gram-positive model, Streptococcus sanguinis. In particular, we focused on the five pilins and pilin-like proteins involved in Tfp biology in S. sanguinis. We found that the two major pilins, PilE1 and PilE2, (i) follow widely conserved principles for processing by the prepilin peptidase PilD and for assembly into filaments; (ii) display only one of the post-translational modifications frequently found in pilins, i.e. a methylated N-terminus; (iii) are found in the same hetero-polymeric filaments; and (iv) are not functionally equivalent. The 3D structure of PilE1, solved by NMR, revealed a classical pilin fold with a highly unusual flexible C-terminus. Intriguingly, PilE1 more closely resembles pseudopilins forming shorter Tff than bona fide Tfp-forming major pilins, underlining the evolutionary relatedness among different Tff. Finally, we show that S. sanguinis Tfp contain a low abundance of three additional proteins processed by PilD, the minor pilins PilA, PilB, and PilC. These findings provide the first global biochemical and structural picture of a Gram-positive Tfp and have fundamental implications for our understanding of a widespread class of filamentous nanomachines.

microbiology↗

bioRxiv2018

Engineered cell-to-cell signalling within growing bacterial cellulose pellicles

Bacterial cellulose is a strong and flexible biomaterial produced at high yields by Acetobacter species and has applications in healthcare, biotechnology and electronics. Naturally, bacterial cellulose grows as a large unstructured polymer network around the bacteria that produce it, and tools to enable these bacteria to respond to different locations are required to grow more complex structured materials. Here, we introduce engineered cell-to-cell communication into a bacterial cellulose-producing strain of Komagataeibacter rhaeticus to enable different cells to detect their proximity within growing material and trigger differential gene expression in response. Using synthetic biology tools, we engineer Sender and Receiver strains of K. rhaeticus to produce and respond to the diffusible signalling molecule, acyl-homoserine lactone (AHL). We demonstrate that communication can occur both within and between growing pellicles and use this in a boundary detection experiment, where spliced and joined pellicles sense and reveal their original boundary. This work sets the basis for synthetic cell-to-cell communication within bacterial cellulose and is an important step forward for pattern formation within engineered living materials.

synthetic biology↗