Report

Teaser, summary, work performed and final results

Periodic Reporting for period 1 - PREMIUM (Preservation of microorganisms by understanding the protective mechanisms of oligosaccharides)

Teaser

Lactic acid bacteria (LAB), are a family of microorganisms widely used for producing a wide diversity of fermented foods. The market of concentrated cultures (starters) is continuously growing due to the development of health products, to the use of plant proteins as...

Summary

Lactic acid bacteria (LAB), are a family of microorganisms widely used for producing a wide diversity of fermented foods. The market of concentrated cultures (starters) is continuously growing due to the development of health products, to the use of plant proteins as fermentation substrate (instead of milk proteins) and also to LAB’s ability to convert by-products for green chemistry applications. The manufacturing of starters requires successive operations that generate stress, potential cellular damage and loss of functionality, in particular following the stabilisation processes: freezing, freeze-drying, or spray drying. Furthermore, the involved operations are usually energy-intensive and result in some negative impacts on the environment.
The aim of PREMIUM is to completely revisit LAB preservation processes to offer original and innovative alternatives benefitting companies and Society, by reviewing all productions steps in light of three main dimensions: product quality, process efficiency and environmental impact.
PREMIUM activities target the understanding of microorganism preservation mechanisms by oligosaccharides, as a promising way for proposing different and more sustainable stabilisation processes relevant for industry and more generally for biodiversity preservation.

Work performed

During the first two years, partners exchanged information, experience and skills, both internationally and across sectors, thus leading to the expansion and enrichment of knowledge on the different topics and methods covered by PREMIUM. This was done through secondments, three face-to-face meetings as well as through the co-supervision of 10 PhD students and collaborative disseminations of results (8 published articles, 2 book chapters and 16 conference participations by way of 6 poster presentations, 8 oral presentations and 2 invited lectures).

Concerning communication, networking and outreach activities (WP6), the visual identity of PREMIUM was created with the design of a logo, a flyer, a website, and various social media accounts (Facebook, Twitter, Instagram). A functional handy workplace was designed also regular videoconferences were held and WP progress reports were delivered every 3 months. Different networking activities were organized by PREMIUM partners: 2 workshops, 14 training sessions and 1 winter school involving around 210 people in total.

The Management and coordination (WP1) activities included: the organization of 3 general meetings and 6 steering committee meetings, a GA amendment, a consortium agreement signature and two amendments, the supervision of secondments and implementation activities, the set up and monitoring of both data and quality management plans, communication with all the WP leaders and intermediation and communication with EC Project Officer.
Work performed from the beginning of the project and main results obtained in the frame of each scientific WP (WP2-5) are:

WP2 (Production and characterization of oligosaccharides and protected LAB):
- set-up of protocols for FOS and GOS enzymatic synthesis;
- finding natural sources to obtain FOS and GOS by hydrolysis and protocol set-ups;
- screening and selection of oligosaccharides for the development of WP3-4-5, by considering their ability to preserve LAB during freezing and freeze-drying, their physical properties (glass transition temperature, water mobility and sorption isotherms) and their production process environmental impact;
- development of specific methods for i) improving production process monitoring and control to obtain oligosaccharides with a defined sugar composition (by vibrational spectroscopy and multivariate analysis) and ii) for fastening the screening of the protective properties of oligosaccharides.

WP3 (Development and optimization of LAB production system):
- set-up of pilot scale production conditions for the three LAB strains studied in PREMIUM;
- set-up of pilot scale freeze-drying and spray drying protocols;
- development of a laboratory scale layer-by-layer encapsulation protocol and initiate pilot scale up;
- sensor installation to collect the necessary data for environmental impact assessments (Life Cycle Assessment);
- development of a sensor supervision system and gathering of complementary data through a questionnaire outline to be filled in by experimenters.

WP4 (Elucidation of mechanisms of LAB degradation/protection):
- measurement of the intracellular glass transition temperature and lipid membrane phase transition temperature of the mammalian cells under study;
- characterization of the physical events occurring within oligosaccharide aqueous solutions and reference components;
- set-up of protocols for RAMAN and FTIR micro-spectroscopy as well as confocal fluorescence microscopy measurements to find LAB markers of cryo-resistance;
- development of experimental and computational approaches to study lipid extracts or the main lipids of the LAB membranes and their interactions with oligosaccharides.

WP5 (Transfer of technology to industry):
- scale-up of FOS produced by enzymatic synthesis to the pilot scale;
- installation of sensors at industrial scale for evaluating of the environmental impact of the LAB production systems;
- first studies on other LAB of commercial interest, and on the protecti

Final results

Progress beyond state of the art and expected results until end of project:
- improvement of knowledge on cell preservation mechanisms (bacteria and mammalian cells);
- expansion of protective molecules sources compliant with clinical applications standards;
- development of novel preservation processes and environmental impact evaluation of the whole microorganism production system, from laboratory to industrial scale;
- development of high-throughput tools for the characterization and screening of protective molecules, and oligosaccharides in particular;
- development of methods for characterizing oligosaccharides production processes by vibrational spectroscopy;
- determination of relevant indicators and elaboration of a robust methodology for comparing stabilisation process alternatives (multicriteria analysis) from laboratory to industrial scale.

Potential impacts:
- improve unicellular organism preservation (biodiversity preservation);
- increase availability and exploitation of promising bacteria for Society (increased diversity and nutritional value of fermented foods and health products, improved preservation of raw food material and reduced food spoilage, green chemistry application);
- future commercial exploitation of obtained results (new mixtures of oligosaccharides as protective compounds, better LAB stabilisation conditions, innovative analytical tools, highlight of energy consumption concerns);
- raise the awareness among starters producers, stakeholders and Society at large to include sustainability approaches in the design and/or improvement of process lines;
- improve the public information and education on topics related to PREMIUM scientific domains (e.g. health and biopreservation benefits of LAB, sustainability, biodiversity preservation);
- enhance skills of partners and researcher interaction with industry;
- boost career prospects of researchers, particularly of early-stage-stage researchers, through knowledge sharing and networking skills during inter-sectoral and international mobility between complementary partners.

Website & more info

More info: http://www.inrae.fr/premium.