Rangées de graines.. © INRA, Elena Schweitzer © Fotolia

Our results

Contents
  1. Introduction
  2. Human milk digestion in the preterm infant: impact of technological treatments
  3. The way in which proteins aggregate when heated may change their sensitising potency
  4. Enhancing the viability of spray-dried probiotic bacteria by stimulating their stress tolerance
  5. To stick or not to stick? Pulling pili sheds new light on biofilm formation
  6. When biopolymers selfassemble: a balance between energy and entropy.
  7. Mimicking the gastrointestinal digestion in a lab-on-a-chip:the microdigester
  8. How a milk droplet becomes a powder grain
  9. Research & Innovation 2016 - For Food and Bioproducts
  10. A new process for the biorefining of plants
  11. Under the UV light : the bacterial membrane
  12. Reverse engineering or how to rebuild ... bread!
  13. Green Chemistry: a step towards lipid production in yeast
  14. Individually designed neo-enzymes for antibacterial vaccines
  15. Multi-scale mechanical modelling: from the nanometric scale to the macroscopic properties of bread crumb
  16. Minimill: 500 g to assess the milling value of soft wheats
  17. Microbial production of lipids for energy or chemical purposes
  18. The discrete role of ferulic acid in the assembly of lignified cell wall
  19. Eco-design of composites made from wood co-products
  20. Analysis of volatile compounds enables the authentication of a poultry production system
  21. Nanoparticles as capping agents for biopolymers microscopy
  22. Pasteurisation, UHT, microfiltration...All the processes don't affect the nutritional quality of milk in the same way
  23. Integration of expert knowledge applied to cheese ripening
  24. Controlling cheese mass loss during ripening
  25. The shape memory of starch
  26. Research & Innovation 2015 - For Food & Biobased Products
  27. Behaviour of casein micelles during milk filtering operations
  28. Overaccumulation of lipids by the yeast S. cerevisiae for the production of biokerosine
  29. Sequential ventilation in cheese ripening rooms: 50% electrical energy savings
  30. An innovative process to extract bioactive compounds from wheat
  31. Diffusion weighted MRI: a generic tool for the microimaging of lipids in food matrices
  32. Characterization of a major gene of anthocyanin biosynthesis in grape berry
  33. New enzyme activity detectors made from semi-reflective biopolymer nanolayers
  34. Improving our knowledge about the structure of the casein micelle
  35. Heating milk seems to favour the development of allergy in infants
  36. Fun with Shape
  37. Using volatile metabolites in meat products to detect livestock contamination by environmental micropollutants
  38. SensinMouth, when taste makes sense
  39. A decision support system for the fresh fruit and vegetable chain based on a knowledge engineering approach
  40. SOLEIL casts light on the 3D structure of proteins responsible for the stabilisation of storage lipids in oilseed plants
  41. A close-up view of the multi-scale protein assembly process
  42. Controlling the drying of infant dairy products by taking water-constituent interactions into account
  43. Polysccharide nanocrystals to stabilise pickering emulsions
  44. Discovery of new degradative enzymes of plant polysaccharides in the human intestinal microbiome
  45. A durum wheat flour adapted for the production of traditional baguettes
  46. Virtual modelling to guide the construction of « tailored-made » enzymes
  47. How far can we reduce the salt content of cooked meat products?
  48. Diffusion of organic substances in polymer materials: beyond existing scaling laws
  49. Smart Foams : various ways to destroy foams on demand !
  50. Dates, rich in tannins and yet neither bitter nor astringent
  51. Sodium content reduction in food
  52. Research & Innovation 2014

To stick or not to stick? Pulling pili sheds new light on biofilm formation

A pilus is an appendage on the cell surface of the majority of Gram-positive bacteria. Pili biogenesis is a machinery that involves a sortase (srtC), an enzyme that covalently assembles protein subunits (pilins) and head-to-tail series to form the backbone (PilB) inL. lactis IL1403 with a tip pilin (PilA) at the distal end of the pilus. This assembly is firmly anchored to the peptidoglycan wall by a PilC anchor pilin.

Updated on 03/29/2017
Published on 03/29/2017
Keywords:

From PlosOne (http://dx.doi.org/10.1371/journal.pone.0152053.g003). © PlosOne, Figure reproduite de la revue scientifique Pl
From PlosOne (http://dx.doi.org/10.1371/journal.pone.0152053.g003) © PlosOne, Figure reproduite de la revue scientifique Pl

It has been demonstrated that under static conditions, pili are involved in self-aggregation and modify the architecture of a growing biofilm. To provide a deeper understanding of the role played by pili in biofilm formation, we focused on the influence of different pilins and sortase C on (i) the adhesion of cells to surfaces under dynamic conditions, and (ii) the nanomechanical properties of pili using single-molecule force spectroscopy.

We have reported that the presence of pili drastically increased the adhesion properties of L. lactison polymeric surfaces and that sortase C was mandatory for cells to sustain shear flow. Force spectroscopy experiments confirmed these requirements and provided data showing extreme flexibility of the pili, much more than DNA strands.This discovery opens up new prospects about homotypic interactions between two cells, in particular, and about self-assembly, in general. This research is ongoing.

A better understanding of the conditions that determine the bacterial colonisation of biotic (e.g., intestinal tract) or abiotic (e.g., milking machine) surfaces remains a major socio-economic issue. Deciphering the nanomechanics of pili and their importance in the adhesion oflactococcimakes it possible to provide the elements necessary to understand the possible role that they play in the formation and structuring of biofilms on relevant sites in the food-processing industry such as milking machines or wood ageing boards for cheese. Eventually, this type of biofilm would make it possible to combat pathogens (e.g.,Listeria) as well as spoilage flora, in order to propose newin finesolutions for food biopreservation.

Mickaël Castelain displays a sample to calibrate the optical the optical tweezers by a interface for control and acquisitio. © Christophe Maître, Christophe Maître
Mickaël Castelain displays a sample to calibrate the optical the optical tweezers by a interface for control and acquisitio © Christophe Maître, Christophe Maître

Contact:

Laboratoire d’Ingénierie des Systèmes Biologiques et des Procédés (LISBP) is a mixed research unit (UMR) attached to INRA (UMR 792), CNRS (UMR 5504) and INSA Toulouse. http://www.lisbp.fr/en/presentation_of_lisbp.html

Partnership:

References:

  • Castelain M, Duviau MP, Canette A, Schmitz P, Loubiere P, Cocaign-Bousquet M, et al. (2016) The Nanomechanical Properties of Lactococcus lactis Pili Are Conditioned by the Polymerized Backbone Pilin. PLoS One 11 (3): e0152053. http://dx.doi.org/10.1371/journal.pone.0152053
  • Castelain M, Duviau MP, Oxaran V, Schmitz P, Cocaign-Bousquet M, Loubiere P, et al. (2016) Oligomerized backbone pilin helps piliatedLactococcus lactisto withstand shear flow. Biofouling 32 (8): 911-923. doi: 10.1080/08927014.2016.1213817

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