title: Microbiota of Minas cheese as influenced by the nisin producer Lactococcus lactis subsp. lactis GLc05.
abstract: Minas cheese is a popular dairy product in Brazil that is traditionally produced using raw or pasteurized cow milk. This study proposed an alternative production of Minas cheese using raw goat milk added of a nisin producer Lactococcus lactis subsp. lactis GLc05. An in situ investigation was carried on to evaluate the interactions between the L. lactis subsp. lactis GLc05 and the autochthonous microbiota of a Minas cheese during the ripening; production of biogenic amines (BAs) was assessed as a safety aspect. Minas cheese was produced in two treatments (A, by adding L. lactis subsp. lactis GLc05, and B, without adding this strain), in three independent repetitions (R1, R2, and R3). Culture dependent (direct plating) and independent (rep-PCR and PCR-DGGE) methods were employed to characterize the microbiota and to assess the possible interferences caused by L. lactis subsp. lactis GLc05. BA amounts were measured using HPLC. A significant decrease in coagulase-positive cocci was observed in the cheeses produced by adding L. lactis subsp. lactis GLc05 (cheese A). The rep-PCR and PCR-DGGE highlighted the differences in the microbiota of both cheeses, separating them into two different clusters. Lactococcus sp. was found as the main microorganism in both cheeses, and the microbiota of cheese A presented a higher number of species. High concentrations of tyramine were found in both cheeses and, at specific ripening times, the BA amounts in cheese B were significantly higher than in cheese A (p<0.05). The interaction of nisin producer L. lactis subsp. lactis GLc05 was demonstrated in situ, by demonstration of its influence in the complex microbiota naturally present in a raw goat milk cheese and by controlling the growth of coagulase-positive cocci. L. lactis subsp. lactis GLc05 influenced also the production of BA determining that their amounts in the cheeses were maintained at acceptable levels for human consumption.
authors: Departamento de Veterinária, Universidade Federal de Viçosa, Campus Universitário, Centro, 36570-900 Viçosa, MG, Brazil; Department of Agricultural, Forest and Food Sciences Microbiology and Food Technology Area, University of Turin, Grugliasco, Italy.
authors: Luana Martins
authors: LM
authors: Perin
authors: Department of Agricultural, Forest and Food Sciences Microbiology and Food Technology Area, University of Turin, Grugliasco, Italy.
authors: Barbara
authors: B
authors: Dal Bello
authors: Department of Agricultural, Forest and Food Sciences Microbiology and Food Technology Area, University of Turin, Grugliasco, Italy.
authors: Simona
authors: S
authors: Belviso
authors: Department of Agricultural, Forest and Food Sciences Microbiology and Food Technology Area, University of Turin, Grugliasco, Italy.
authors: Giuseppe
authors: G
authors: Zeppa
authors: Departamento de Tecnologia de Alimentos, Universidade Federal de Viçosa, Campus Universitário, Centro, 36570-900 Viçosa, MG, Brazil.
authors: Antônio Fernandes de
authors: AF
authors: Carvalho
authors: Department of Agricultural, Forest and Food Sciences Microbiology and Food Technology Area, University of Turin, Grugliasco, Italy. Electronic address: lucasimone.cocolin@unito.it.
authors: Luca
authors: L
authors: Cocolin
authors: Departamento de Veterinária, Universidade Federal de Viçosa, Campus Universitário, Centro, 36570-900 Viçosa, MG, Brazil. Electronic address: nero@ufv.br.
authors: Luís Augusto
authors: LA
authors: Nero
mesh_terms: D000818:Animals; D001679:Biogenic Amines / Q000032:analysis* / Q000096:biosynthesis; D001938:Brazil; D002417:Cattle; D002611:Cheese / Q000032:analysis / Q000382:microbiology*; D003030:Coagulase / Q000378:metabolism; D005260:Female; D005516:Food Microbiology; D006041:Goats; D013294:Lactococcus lactis / Q000254:growth & development*; D064307:Microbiota; D009561:Nisin / Q000096:biosynthesis*
chemical_list: D001679:Biogenic Amines; D003030:Coagulase; D009561:Nisin; C102526:nisin A
keywords: Biogenic amines; Microbial ecology; Minas cheese; PCR-DGGE; Raw goat milk; Rep-PCR