A rheological approach to identify efficient biopolymer producing bacteria.

This study investigates the relationship between collective motion and propulsion of bacterial consortia and their biopolymer production efficiency. Rheological tests were conducted for suspensions of two different methanotrophic bacterial consortia obtained after enrichment of sediment samples from mangrove sites in Brazil. We considered the linear viscoelasticity region and analyzed the values of storage and loss moduli as functions of days of cultivation, for different values of the volume fraction. The suspensions' rheological behaviors reflected the bacterial growth stage. We found that the formation of structures over time in some types of consortia can hinder the movement of bacteria in the search for nutrients. The change in complex viscosity of the two consortia followed a different and rich behavior that appears to be closely related to their capacity to capture methane. Our analysis showed a possible correlation between collective motion, viscosity reduction, and biopolymer production. The pieces of evidence from this study suggest that the efficiency of bacterial motion is directly related to biopolymer production, and this could facilitate the process of identifying the best consortium of biopolymer producing bacteria.

MALDI-Biotyper as a tool to identify polymer producer bacteria.

The methylotrophs bacteria can use methane and methanol as carbon sources to produce biopolymers including the polyhydroxybutyrate (PHB) a very promised substitute for the environment contaminant oil-derived polypropylene. This kind of bacteria can be very effective to help to decrease PHB price production and promote its use in substitution of several environment contaminant plastics. The search for methylotroph bacteria able to produce PHB is a very arduous job being necessary to grow all isolates and submit all of them to extraction processes and product characterization. Looking for time reducing and optimization of resources, we tested the Matrix Assisted Laser Desorption/Ionization technique (MALDI-Biotyper) to identify polymer producer bacteria based on a single isolated colony with success. The results showed here will contribute to speed-up and increase the discoveries of new bacteria strains able to produce PHB and other biopolymers.