Investigating the influence of Food Safety Management Systems (FSMS) on microbial diversity of Canastra cheeses and their processing environments.

Canastra Cheese is one of the most commercialized artisanal cheeses in Brazil and intrinsic characteristics of its production, such as the use of raw milk and natural whey starter cultures as well short ripening time on wooden shelves, offer risk of contamination by a plethora of microorganisms. Here, we used 16 S rRNA gene amplicon sequencing approach to characterize the bacterial communities from Canastra cheese processing environments and final products, accessing cheesemaking facilities with distinct profiles of Food Safety Management Systems (FSMS), in order to estimate whether differences in microbial composition and diversity could also be observed between the two sampled groups of facilities. Our results revealed that the diversity of bacterial communities in the processing environments was much higher than that observed for cheeses, with greater discrepancy for facilities with inadequate FSMS. Additionally, in facilities with inadequate FSMS the bacterial communities from environments, especially hand surfaces and ripening wooden shelves, were similar to those during processing and finished cheese. These evidences highlight the importance of implementing and maintaining FSMS in the facilities, in order to assure quality and safety of Canastra cheese, but also the stability and economic viability of the Canastra cheese production chain.

Dynamics of microbial contaminants is driven by selection during ethanol production.

Brazil is the second largest ethanol producer in the world and largest using sugarcane feedstock. Bacteria contamination is one of the most important issues faced by ethanol producers that seek to increase production efficiency. Each step of production is a selection event due to the environmental and biological changes that occur. Therefore, we evaluated the influence of the selection arising from the ethanol production process on diversity and composition of bacteria. Our objectives were to test two hypotheses, (1) that species richness will decrease during the production process and (2) that lactic acid bacteria will become dominant with the advance of ethanol production. Bacterial community assemblage was accessed using 16S rRNA gene sequencing from 19 sequential samples. Temperature is of great importance in shaping microbial communities. Species richness increased between the decanter and must steps of the process. Low Simpson index values were recorded at the fermentation step, indicating a high dominance of Lactobacillus. Interactions between Lactobacillus and yeast may be impairing the efficiency of industrial ethanol production.