Dissemination Content

Purple Bubbles

PurpleGain COST Action

First Purple Bubbles: Amsterdam, Netherlands 05/06/2024

The first Purple Bubble was hosted by LGem in Amsterdam, bringing together 14 participants, including 6 academic institutes and 4 companies from the nutraceutics and food sectors. A technical tour showcased LGem’s facilities, followed by a round-table discussion addressing key bottlenecks in biomass valorisation and PPB industrialisation.

Second Purple Bubble: Linares, Spain 26/06/2024

The second Purple Bubble took place in Linares, Spain, bringing together 7 participants, including 2 academic institutes and 3 companies from wastewater and paper sectors. Participants visited Aqualia’s demo-scale Purple Bacteria reactor, the first of its kind.
The technical tour highlighted the operational setup, system performance and practical deployment challenges of PPB-based wastewater treatment.

Third Purple Bubble: Skopje, North Macedonia 20/09/2024

The third Purple Bubble in Skopje gathered 20 participants from sectors including waste, coffee and pharmaceuticals. Attendees were introduced to Purple Bubbles and joined a thematic lecture on PPB applications. The event also featured a PurpleGain showcase, highlighting advances in resource recovery and novel bioproduct opportunities.

Fourth Purple Bubble: Novi Sad, Serbia 12/06/2025

The fourth Purple Bubble in Novi Sad focused on carotenoid extraction techniques, addressing conventional vs. ultrasound-assisted methods, DES/NADES solvents, etc. Participants explored regulatory aspects for carotenoid use in food and dietary supplements and viewed modelling demonstrations for predicting carotenoid bioactivity. The event welcomed 14 participants from the cosmetic sector and included a PurpleGain showcase.

Fifth Purple Bubble: Venice, Italy 18/06/2025

The fifth Purple Bubble in Venice addressed PPB applications for energy and
resource recovery. The event gathered 14 participants, including 6 companies from
sectors such as spirulina production, oil & gas, ultrasound technology and engineering.
Discussions focused on sustainable valorisation processes and industrial integration
pathways.

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First Purple Bubbles: Amsterdam, Netherlands

05/06/2024

The first Purple Bubble event marked the launch of a stakeholder- engagement series dedicated to Purple Phototrophic Bacteria technologies. Hosted by LGem in Amsterdam, the workshop gathered participants from academia, biotechnology and food-related industries. After introductory presentations, attendees joined a comprehensive technical tour of LGem’s cultivation systems. A round table enabled deep discussion on biomass valorisation challenges: production costs, quality requirements, regulatory differences among countries, contamination risks, and constraints of microalgae and PPB technologies. The debate highlighted light demand
as the primary economic bottleneck, with up to 60% of total costs linked to electricity, and 99% of this due to illumination.
Additional topics included PPB application in microbial anaerobic reactors, scaling strategies, and potential markets in food and feed applications.

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Second Purple Bubble: Linares, Spain 

26/06/2024

The second Purple Bubble focused on industrial-scale demonstration of PPBtechnology. Hosted by Aqualia, the visit featured an in-depth technical tour of the first PPB demo-scale reactor, offering participants a unique look at full-scale operational conditions.
Discussions revolved around wastewater-sector applications, reactor performance, and integration potential with existing treatment infrastructures. The event strengthened collaboration between academia, wastewater companies, and industrial partners interested in circular water processes.

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Third Purple Bubble: Skopje, North Macedonia

20/09/2024

Held in Skopje, this Purple Bubble expanded the network of stakeholders
exploring PPB opportunities across multiple industries. The event attracted participants
from waste management, coffee production and pharmaceutical sectors. The programme
included a presentation on the Purple Bubbles initiative, a lecture on PPB capacities, and
a showcase of PurpleGain innovations, providing insights into real-world industrial and
environmental applications.

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Fourth Purple Bubble: Novi Sad, Serbia

12/06/2025

This edition of Purple Bubbles centred on microbial carotenoids, their structure, extraction and industrial application potential. Sessions covered a wide spectrum of extractionstrategies—from conventional and ultrasound-assisted techniques to DES/NADES methodologies and supramolecular solvent systems.
Regulatory considerations regarding food and supplement markets were discussed, along with an in-silico modelling demonstration predicting carotenoid bioactivity. The workshop gathered professionals from the cosmetics industry and concluded with a PurpleGain showcase, emphasising technological transfer opportunities.

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Fifth Purple Bubble: Venice, Italy

18/06/2025

This edition focused on innovative PPB-based strategies for energy generation and resource recovery. Experts from multiple industries explored practical implementation scenarios, cost structures and environmental benefits of PPB technologies. The event highlighted industrial case studies, market needs and future opportunities to incorporate PPB into circular economy solutions.

COST (European Cooperation in Science and Technology) is a funding agency for research and innovation networks. Our Actions help connect research initiatives across Europe and enable scientists to grow their ideas by sharing them with their peers. This boosts their research, career and innovation.
www.cost.eu