Does Smearing Inoculum Reflect the Bacterial Composition of the Smear at the End of the Ripening of a French Soft, Red-Smear Cheese?

Abstract

The microbial community composition and dynamics during the production of a French soft, red-smear cheese were investigated. The colonization efficiency of the smearing inoculum was followed, and the parts played by the inoculum used and the resident microflora were tentatively estimated. Single-strand conformation polymorphism analysis (SSCP) was applied to 2 productions of a soft, red-smear cheese produced by the same dairy plant at 4-mo intervals. Microbial composition of the different cheese samples analyzed was found to be reproducible from one production to another. However, the composition of the surface flora of both cheeses at the end of the ripening did not reflect the composition of the smearing inoculum used, qualitatively as well as quantitatively. These results were confirmed by those obtained when assessing the microbial composition of the culturable flora by the spread plate technique. The inoculum used by the industry had low resiliency potentialities against colonization of cheeses by resident organisms. Therefore, fitness and colonization potential of smearing inocula should be carefully assessed by the industry before use. The use of Arthrobacter strains as part of the smearing inoculum should be evaluated.

Application of PCR-Based Methods to Dairy Products and to Non-Dairy Probiotic Products

“…Bacterial diversity may also be assessed by sequencing clones libraries generated from 16S rRNA gene amplification of DNA extracted from dairy products (Feurer et al, 2004a;Feurer et al, 2004b;Delbes et al, 2007;Rasolofo et al, 2010;Carraro et al, 2011). The main advantage of this technique is that no dedicated database is needed, as the sequences are already available in public genomic databases.…”

“…Single-strand conformation polymorphism-PCR (SSCP-PCR) is another PCR-based method for microbial diversity investigation that has been applied to dairy products (Duthoit et al, 2003;Feurer et al, 2004a;Feurer et al, 2004b;Delbes and Montel, 2005;Duthoit et al, 2005;Callon et al, 2006;Delbes et al, 2007;Saubusse et al, 2007;Mounier et al, 2009). This technique is based on the sequence-dependent differential intra-molecular folding of single strand DNA, which alters the migration speed of the molecules under non-denaturing conditions.…”

“…The hypervariable regions are flanked by conserved sequences, which can serve for amplification with "universal" primers (Baker et al, 2003). The variable V1 Bonetta et al, 2008), V3 Ercolini et al, 2001;Ogier et al, 2002;Duthoit et al, 2003;Ercolini et al, 2003;Mauriello et al, 2003;Andrighetto et al, 2004;Ercolini et al, 2004;Feurer et al, 2004a;Feurer et al, 2004b;Lafarge et al, 2004;Ogier et al, 2004;Duthoit et al, 2005;Flórez and Mayo, 2006;Delbes et al, 2007;El-Baradei et al, 2007;Parayre et al, 2007;Abriouel et al, 2008;Ercolini et al, 2008;Gala et al, 2008;Van Hoorde et al, 2008;Alegría et al, 2009;Casalta et al, 2009;Dolci et al, 2009;Giannino et al, 2009;Mounier et al, 2009;Serhan et al, 2009;Dolci et al, 2010;Fontana et al, 2010;Van Hoorde et al, 2010;Masoud et al, 2011), V2 (Duthoit et al, 2003;Delbes and Montel, 2005;Saubusse et al, 2007), V4-V5 , V1-V3 (Randazzo et al, 2002), V4-V8 (Randazzo et al, 2006), V5-V6 (Le Bourhis et al, 2005;Le Bourhis et al, 2007) and V6-V8 …”

“…The ITS2 region has been chosen as target for the study of the fungal biodiversity of smear-ripened cheeses , and the ITS1 region for the study of the fungal diversity in cow, goat and ewe milk (Delavenne et al, 2011). Primers targeting regions of the 26S rRNA (Feurer et al, 2004b;Flórez and Mayo, 2006;Bonetta et al, 2008;Alegría et al, 2009;Dolci et al, 2009;Mounier et al, 2009) and the 18S rRNA (Callon et al, 2006;Arteau et al, 2010) were chosen to investigate the dominant yeast microflora of several types of cheeses.…”

“…In direct DNA extraction procedures (McKillip et al, 2000;Duthoit et al, 2003;Feurer et al, 2004a;Feurer et al, 2004b;Callon et al, 2006;Monnet et al, 2006;Delbes et al, 2007;Masoud et al, 2011), the cheese samples are first homogenised in a liquid solution by a method involving bead-beating, a mortar and pestle or other mechanical treatments. Efficient treatments of casein degradation and cell lysis, followed by phenol/chloroform extractions, are then needed to remove most contaminating compounds.…”