Bactereature

Fourteen ceramic sculptures grown in collaboration with Serratia marcescens, a pigment-producing bacterium that colonises 3D-printed surfaces. Colour and form emerge from bacterial growth rather than being applied, the organism acting as co-author rather than material.

Concept

Serratia marcescens is a bacterium commonly found on and in the human body — known clinically as an opportunistic pathogen, and domestically as the pink residue that collects in damp grout and shower grime. Cultured under controlled conditions, it secretes prodigiosin, a red pigment historically mistaken for blood and once read as a religious portent before its microbial origin was identified.

Bactereature asks what happens when this same organism is invited onto a ceramic surface not as contamination to be eliminated, but as a collaborator in the making of an object — where responsibility for the resulting form and colour comes to rest between the artist, the print and the bacterium.

A single Petri dish on a white ground, streaked with red Serratia marcescens colonies across pale nutrient agar. — Growth of Serratia marcescens after 72 h

Pigmentation

Serratia marcescens produces prodigiosin, an intense red secondary metabolite. It grows readily on standard nutrient media and develops visible pigmentation under moderate conditions. In contrast to the violet associated with the more commonly used Janthinobacterium lividum, its red pigment introduces a different chromatic range, allowing the bacterium to act as an active contributor to material experimentation.

The strain was first activated on nutrient agar for 72 hours at 28°C and 80% relative humidity under light-protected conditions. Pigmented colonies were then resuspended in nutrient broth to form a liquid staining medium. Materials were placed semi-immersed in the suspension, drawing the pigment-bearing liquid upward through capillary action. Colouration emerged through absorption, diffusion and deposition, rather than being applied as a fixed surface finish.

Gloved hands holding an open Petri dish of red Serratia marcescens colonies beside a dropper bottle and an inoculation loop. — Serratia marcescens activation before staining

Twenty-seven Petri dishes on a white ground, each holding a different material sample stained across a range of reds and oranges by Serratia marcescens. — Material screening across different substrates

A six-frame grid: three porcelain cups standing in red medium under bell jars, and the three resulting cups stained from a soft gradient to near-solid pink. — Porcelain staining under three exposure conditions

Screening

A range of materials was tested under the same staining conditions, including textiles, plant fibres, animal surfaces and shells, clay, wood, and metal. The comparison focused on how readily each material absorbed the pigment-bearing liquid and how clearly the colour remained visible at the surface.

Bisque-fired, unglazed porous ceramic was selected as the carrier. While many textiles produced broad, even saturation, ceramic drew liquid upward through capillary action and retained pigment close to the surface, creating diffusion gradients, tide lines and sediment-like traces.

Layer-by-layer extrusion of porcelain clay

The open-source clay printer in operation

Forming the substrate

The textured forms were printed in high-white porcelain clay using an open-source clay 3D printer and Cura for slicing. Printing parameters, support structures and internal configurations were adjusted for each geometry to maintain stability while preserving the intended surface textures. The layer-by-layer traces were deliberately retained as readable surface features that later participate in liquid absorption and pigment deposition.

The green bodies were air-dried before being bisque-fired at 800°C without glaze. Firing hardened and stabilised the forms while retaining the microporous ceramic structure, preparing the surface for the wet staining and microbial processes that followed, where absorption and diffusion remained active.

Close view of a glass tube of nutrient medium lit from below, an orange-red prodigiosin film webbed across the surface where the liquid meets the air. — The pigment film where the medium meets air

Glass-cube vitrines on wire incubator shelves, each holding a textured ceramic piece standing in shallow red pigment medium, the pieces coloured from white at the base to pink at the top. — Base absorption and surface inoculation combined during incubation

A gloved hand uses a dropper to inoculate bacteria onto a textured pink and white ceramic piece inside a glass tank, a second piece alongside. — Localised inoculation into selected grooves

Two colouration pathways on one sample

Colour pathways

Two complementary colouration pathways were combined on the same ceramic sample. Capillary absorption drew pigment-bearing liquid upward through the porous body, leaving soft gradients and tide-like marks along the printed layers, while localised inoculation concentrated pigmentation within selected grooves and cavities.

Together, the two produced distinct but overlapping colour distributions. Pigment developed most strongly where liquid meets air, since oxygen is critical to its production. Rather than functioning as a one-time coating, colouration developed through absorption, microbial activity and time, leaving material traces shaped by the ceramic surface and its environment.

A grid of fourteen unglazed textured ceramic pieces on a white ground, each front-on, ranging from near-white to deep pink where bacterial pigment has stained the printed layers. — Unglazed, textured ceramics stained with pigment-producing bacteria

A stained ceramic piece on a white block on an aluminium-frame plinth, a glass reservoir of pigment medium suspended on the shelf below, connected by tubing. — Installation view

Close view of one piece on its plinth: thick printed coils running white to deep pink, the layered surface catching the pigment unevenly. — Installation view

A two-tier aluminium-frame plinth: a piece in a glass vitrine standing in red medium above, a bare piece below, and a feed bottle at the base. — Installation view

The full Bactereature series in a white gallery: a row of slender metal-frame plinths, each carrying a pale ceramic sculpture on top, a pink-stained piece mid-shelf and an orange feed bottle below, a lit column at the centre and a visitor walking past. — Installation view of Bactereature

Fourteen sculptures

Fourteen unglazed, textured ceramic pieces make up Bactereature. Produced through the same material and microbial system, each developed a distinct pattern of pigment migration, accumulation and boundary formation.

Rather than aiming for an even colour, the series foregrounds variation itself, with each form registering a different interaction between printed geometry, porous ceramic and microbial activity.

Credits

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