Biodiversity of the Surface Microbial Consortia from Limburger, Reblochon, Livarot, Tilsit, and Gubbeen Cheeses
Authors: Cogan Timothy M. , Goerges Stefanie , Gelsomino Roberto , Larpin Sandra , Hohenegger Markus , Bora Nagamani , Jamet Emmanuel , Rea Mary C. , Mounier Jérôme , Vancanneyt Marc , Guéguen Micheline , Desmasures Nathalie , Swings Jean , Goodfellow Mike , Ward Alan C. , Sebastiani Hans , Irlinger Françoise , Chamba Jean-Francois , Beduhn Ruediger , Scherer Siegfried 
Published: April 2014

ABSTRACT

Comprehensive collaborative studies from our laboratories reveal the extensive biodiversity of the microflora of the surfaces of smear-ripened cheeses. Two thousand five hundred ninety-seven strains of bacteria and 2,446 strains of yeasts from the surface of the smear-ripened cheeses Limburger, Reblochon, Livarot, Tilsit, and Gubbeen, isolated at three or four times during ripening, were identified; 55 species of bacteria and 30 species of yeast were found. The microfloras of the five cheeses showed many similarities but also many differences and interbatch variation. Very few of the commercial smear microorganisms, deliberately inoculated onto the cheese surface, were reisolated and then mainly from the initial stages of ripening, implying that smear cheese production units must have an adventitious “house” flora. Limburger cheese had the simplest microflora, containing two yeasts,
Debaryomyces hansenii
and
Geotrichum candidum
, and two bacteria,
Arthrobacter arilaitensis
and
Brevibacterium aurantiacum
. The microflora of Livarot was the most complicated, comprising 10 yeasts and 38 bacteria, including many gram-negative organisms. Reblochon also had a very diverse microflora containing 8 yeasts and 13 bacteria (excluding gram-negative organisms which were not identified), while Gubbeen had 7 yeasts and 18 bacteria and Tilsit had 5 yeasts and 9 bacteria.
D. hansenii
was by far the dominant yeast, followed in order by
G. candidum
,
Candida catenulata
, and
Kluyveromyces lactis
.
B. aurantiacum
was the dominant bacterium and was found in every batch of the 5 cheeses. The next most common bacteria, in order, were
Staphylococcus saprophyticus
,
A. arilaitensis
,
Corynebacterium casei
,
Corynebacterium variabile
, and
Microbacterium gubbeenense
.
S. saprophyticus
was mainly found in Gubbeen, and
A. arilaitensis
was found in all cheeses but not in every batch.
C. casei
was found in most batches of Reblochon, Livarot, Tilsit, and Gubbeen.
C. variabile
was found in all batches of Gubbeen and Reblochon but in only one batch of Tilsit and in no batch of Limburger or Livarot. Other bacteria were isolated in low numbers from each of the cheeses, suggesting that each of the 5 cheeses has a unique microflora. In Gubbeen cheese, several different strains of the dominant bacteria were present, as determined by pulsed-field gel electrophoresis, and many of the less common bacteria were present as single clones. The culture-independent method, denaturing gradient gel electrophoresis, resulted in identification of several bacteria which were not found by the culture-dependent (isolation and
rep
-PCR identification) method. It was thus a useful complementary technique to identify other bacteria in the cheeses. The gross composition, the rate of increase in pH, and the indices of proteolysis were different in most of the cheeses.