Identification of lactic acid bacteria with anti-listeria activity. Characterization and application of a bacteriocinogenic strain in the control of in cheese.

The purpose of the research paper was firstly to identify bacteriocin-producing lactic acid bacteria characterizing strains with anti-listeria activity and, secondly, to characterize bacteriocin evaluating its in vitro efficiency as a natural preservative and, thirdly, to evaluate the anti-listeria effect of the bacteriocinogenic strain of in cheeses and produce an edible film with anti-listerial effect. Of 355 lactic acid bacteria strains tested, two were able to produce bacteriocin against and were identified as and . A bactericidal effect of strain QS494 () was observed in the first 8 h, with a reduction of 1.

X-ray diffraction has limited applicability in investigation of milk tampering.

The aim of this work was to use X-ray diffraction to identify substances used for adulteration of raw milk and to determine if crystallographic analysis can detect extraneous substances in milk. Two unknown substances were sent anonymously by employers linked to the dairy chain, who claimed that they were added directly in milk prior to water addition by truck drivers. The samples were analyzed by X-ray diffraction and submitted to physicochemical analysis.

Short communication: Effect of bactofugation of raw milk on counts and microbial diversity of psychrotrophs.

Bactofugation is a centrifugal process for removing spores of microorganisms from milk, especially when it is destined for cheese making. Other microorganisms may be removed in bactofugation. This study aimed to verify the effect of milk bactofugation on the counts and microbial diversity of psychrotrophs.

Selection of Leuconostoc strains isolated from artisanal Serrano Catarinense cheese for use as adjuncts in cheese manufacture.

Background: Serrano Catarinense cheese is a raw bovine milk cheese produced in the region of Santa Catarina, Brazil. Twelve representative strains of Leuconostoc isolated from 20 samples of this artisanal cheese were selected and submitted for evaluation of the acidifying, proteolytic, autolytic, aminopeptidase and lipolytic activities, NaCl and acid resistance, production of dextran and biogenic amines and antimicrobial activity. The aim was to genetically and technologically characterize the Leuconostoc strains in order to use them in mixed starter cultures for cheese manufacture.

Complete Genome Sequence of Streptococcus agalactiae Strain S25 Isolated from Peritoneal Liquid of Nile Tilapia.

Streptococcus agalactiae (Lancefield group B; GBS) is one of the major pathogens in fish production, especially in Nile tilapia (Oreochromis niloticus). The genomic characteristics of GBS isolated from fish must be more explored. Thus, we present here the genome of GBS S25, isolated from Nile tilapia from Brazil.

Screening and enumeration of lactic acid bacteria in milk using three different culture media in Petrifilm Aerobic Count plates and conventional pour plate methodology.

This study aimed to compare Petrifilm Aerobic Count (AC) plates and the conventional pour plate methodology using de Mann-Rogosa-Sharpe (MRS), Kang-Fung (KF) and Kang-Fung-Sol (KFS) culture media for screening and enumeration of lactic acid bacteria (LAB) in milk. Suspensions of 10 LAB species in reconstituted powder skim milk and 30 raw milk samples, without experimental inoculation, were tested. For selective enumeration, all samples were previously diluted in MRS, KF and KFS broths and then plated in Petrifilm AC and conventional pour plate methodology, using the same culture media with added agar.

Interference of raw milk autochthonous microbiota on the performance of conventional methodologies for Listeria monocytogenes and Salmonella spp. detection.

Pathogen detection in foods by reliable methodologies is very important to guarantee microbiological safety. However, peculiar characteristics of certain foods, such as autochthonous microbiota, can directly influence pathogen development and detection. With the objective of verifying the performance of the official analytical methodologies for the isolation of Listeria monocytogenes and Salmonella in milk, different concentrations of these pathogens were inoculated in raw milk treatments with different levels of mesophilic aerobes, and then submitted to the traditional isolation procedures for the inoculated pathogens.

Listeria monocytogenes: Occurrence in beef and identification of the main contamination points in processing plants.

This study aimed to establish the occurrence of Listeria spp., especially L. monocytogenes and its main serotypes, in beef and processing plants.