Abstract The serrano artisanal cheese (SAC) is a traditional raw milk dairy produced in southern Brazil. The maturation temperature plays a crucial role regarding the cheeses’ microbiological and physicochemical features and has been underexplored when it comes to unpasteurized milk dairy in Brazil. The objective of the present work is to evaluate the effect of ripening temperature on foodborne bacteria (total and thermotolerant coliforms, positive coagulase Staphylococcus and the production of its enterotoxin, Listeria monocytogenes, Escherichia coli and Salmonella spp.) and physicochemical attributes (moisture, water activity, pH, acidity and sodium chloride concentration) of SAC during maturation at 5ºC-20ºC for up to 60 days. Metagenomic analysis was also evaluated through the rDNA 16S method at ripening time of 0-60 days. The samples were safe for L.monocytogenes, E.coli, Salmonella spp. and staphylococcal toxin. The physicochemical parameters reached legal boundaries as follows: moisture, after 30 days at 5ºC; fat, after 30 days at 12.5ºC and 20ºC; fat at dry extract, after 30 days at 12.5ºC or 15 days at 5ºC. The microbiological features indicate that positive coagulase Staphylococcus reached legal conditions after 30 days when cheeses were ripped at 12.5ºC and 20ºC; thermotolerant coliforms after 30 days at 12.5ºC and 20ºC; and total coliforms after 15 days at 20ºC. Lower temperatures lead to lower inactivation rates, and Staphylococcus did not reach legal parameters at 5ºC positive coagulase regarding moisture, water activity and pH reduction. Meanwhile, sodium chloride concentration and enhanced acidity played important role regarding foodborne pathogen inactivation. The main lactic acid bacteria within the cheeses during ripening were Enterococcus sp. and Lactococcus sp.

P34 is an antimicrobial peptide produced by a Bacillus sp. strain isolated from the intestinal contents of a fish in the Brazilian Amazon basin with reported antibacterial activity. The aim of this work was to evaluate the peptide P34 for its in vitro antiviral properties against canine adenovirus type 2 (CAV-2), canine coronavirus (CCoV), canine distemper virus (CDV), canine parvovirus type 2 (CPV-2), equine arteritis virus (EAV), equine influenza virus (EIV), feline calicivirus (FCV) and feline herpesvirus type 1 (FHV-1). The results showed that the peptide P34 exhibited antiviral activity against EAV and FHV-1. The peptide P34 inhibited the replication of EAV by 99.9% and FHV-1 by 94.4%. Virucidal activity was detected only against EAV. When P34 and EAV were incubated for 6 h at 37 °C the viral titer reduced from 10(4.5) TCID50 to 10(2.75) TCID50, showing a percent of inhibition of 98.6%. In conclusion, our results demonstrated that P34 inhibited EAV and FHV-1 replication in infected cell cultures and it showed virucidal activity against EAV. Since there is documented resistance to the current drugs used against herpesviruses and there is no treatment for equine viral arteritis, it is advisable to search for new antiviral compounds to overcome these infections.

The antimicrobial activity of the bacteriocin-like substance (BLS) P34 against Listeria monocytogenes was investigated in chicken sausage. The BLS was applied to chicken sausages (256 AU g-1) previously inoculated with a suspension of 10² cfu g-1 of L. monocytogenes. BLS P34 inhibited the indicator microorganism in situ in all incubation times for up to 10 days at 5 °C. The effectiveness of BLS P34 was increased when it was added in combination with nisin. The bacteriocin was also tested in natural eatable natural bovine wrapping (salty semi-dried tripe) against the same indicator microorganism, also showing inhibitory capability in vitro. BLS P34 showed potential to control L. monocytogenes in refrigerated meat products.