Bagasse is the solid residue left after the beer fermentation process, which is considered a production waste, or is sometimes used as livestock feed.
The main objective of the BIOVALORA project was to obtain materials and substances with added value for other sectors, such as biotechnology to obtain functional ingredients, nutrients, probiotics and prebiotics, and plant fibers that were also used as a filler or additive in the transformation of plastics, from the processing of bagasse waste from beer manufacturing.
In this cooperation project financed by the AVI and the European Union through the ERDF, three entities participate: the Polytechnic University of Valencia, AIJU and BIOITHAS.
Because bagasse undergoes a fermentation process during beer production, BIOITHAS established the hypothesis that some microorganisms with probiotic potential, such as bacteria or yeasts, could be present in this waste.
MICROBIOLOGICAL CHARACTERIZATION
First, the microbiological characterization of the bagasse residue was carried out with two different objectives: (1) determine the possible presence of contaminating microorganisms dangerous to human health, and (2) isolate and identify microorganisms with potential use as probiotics, especially bacteria ( lactobacillus and bifidobacteria) and yeasts.
To do this, bagasse samples were requested from two different types of breweries: industrial and artisanal, in order to identify possible microbiological differences depending on the beer production method, and sowing was carried out in different selective culture media.
More than 70 microorganisms were isolated in the different bagasse samples, and they were identified to determine what species they were through 16S rRNA gene sequencing and analysis. Finally, approximately 35 different species were identified, although the vast majority of the species identified were microorganisms considered pathogenic, so they cannot be proposed for use as probiotics.
Legislatively, one of the fundamental points for a microorganism to be included as a probiotic in foods or food supplements is that they have the QPS ( Qualified Presumption of Safety ) qualification by the EFSA ( European Food Safety Authority ). Therefore, it was decided to continue further studies with the identified strain of the lactic acid bacteria Pediococcus acidilactici .
Although the P. acidilactici species has the QPS qualification and can be used in the food industry, many characteristics of probiotics are dependent on the specific strain, which is why the strain was studied in depth, including carrying out the complete sequencing of its genome and in vitro analysis to study other probiotic characteristics.
IN VITRO STUDIES OF THE ISOLATED PROBIOTIC STRAIN
First, the complete genome sequencing of the isolated Pediococcus acidilactici strain was carried out, with the aim of identifying differences with other strains of that same species, also analyzing the possible presence of virulence factors and antibiotic resistance. The results showed that the strain did not have genetic elements that compromise its safety, so the isolated P. acidilactici strain can be used as a probiotic in food.
Subsequently, and to begin with the characterization of the probiotic properties of the isolated P. acidilactici strain, tests were carried out to analyze its ability to stimulate the release of intestinal hormones and the immune response in vitro (pro- and anti-cytokines). inflammatory). The results showed that incubation with Pediococcus induces an increase in the secretion of the YY peptide in STC-1 cells, as well as that they seem to show the anti-inflammatory potential of P. acidilactici in view of the lower induction of TNF-production. α.
CLINICAL TRIALS APPROACH
Following the results obtained in the in vitro analyzes with the P. acidilactici strain, the probiotic potential of this lactic acid bacteria in patients with obesity was considered, since it increases the production of the peptide YY (PYY), which participates in the regulation appetite and satiety, influencing body weight and energy expenditure.
After a bibliographic search of the published evidence involving this species, as well as the methodological design of other clinical trials with probiotics in patients with obesity, the clinical trial protocol was developed and all the necessary documentation to be able to be evaluated by a Ethics Committee.
Likewise, work was done on the formulation of the product to be used in the clinical trial, both the probiotic product and the placebo that will be used as a comparator.
