Cutting wedge: bacterial community diversity and structure associated with the cheese rind and curd of seven natural rind cheeses

Abstract

The microorganisms that inhabit cheese contribute greatly to the flavor and development of the final product. While the rind and curd microbiota have been characterized separately, there is limited information on how the structure and function of microbial communities in rinds and curds vary within and amongst cheeses. To better understand the differences in community structure and function between communities of cheese rinds and curds, we combined culture-based methods with culture-independent community profiling of curds and rinds. Rinds contained greater taxonomic diversity than curds. Lactobacillales dominated curd communities while members from the order Actinomycetales were found in high abundance in rind communities. Communities varied more between rinds and curds than among cheeses produced from different milk types. To better understand microbial community functions, we cultured and assayed isolates for antibiotic susceptibility and carbon source utilization. Among European and U.S. cheeses, 70% of all susceptible isolates were cultured from U.S. cheeses. Overall, our study explored the differences within and between rind and curd microbial communities of natural rind cheeses, provided insights into the environmental factors that shape microbial communities, and demonstrated that at the community and isolate level the cheese microbiome was diverse and metabolically complex.

Study of the microbial diversity of a panel of Belgian artisanal cheeses associated with challenge studies for Listeria monocytogenes

“…Kamimura et al (2020) suggested that Lactococcus and Streptococcus are the most adapted genera regarding physicochemical conditions met during cheese production, ripening and storage. In Gruyere and Comte, a co-dominance of Streptococcus with Lactobacillus was already observed (Wei et al, 2016), but Lactobacillus was never in dominant position in our samples. During a study on Rushan cheese, Xue et al (2018) identified Acetobacter and Acinetobacter as (co-)dominant genera but, in the present study, these genera were either not detected or had a really low relative abundance (< 0.1%), respectively.…”

“…Brevibacterium had an important relative abundance (> 10% at day-0 and end of shelf-life) in SRSC. Bacteria from these genera are rind colonizers, especially Brevibacterium linens, which is responsible for the red-orange color of SRSC rinds and was used as ripening starter in SRSC manufacture (Fox et al, 2017;Wei et al, 2016).…”

“…As already mentioned, Staphylococcus was observed in SRSC samples during this study, but it was not the case of Micrococcus. As alkalophiles, the presence of the genera Corynebacterium and Brachybacterium on the surface of washed rind cheeses is common, provided that this environment is de-acidified due to the metabolic activities of yeasts and moulds (Wei et al, 2016). In this study, relative abundance of Corynebacterium was relatively low, especially at day-0 (0.1 ± 0.4% in SPSHC and 0.2 ± 0.4% in SRSC), but was increased in SRSC at the end of shelf-life (1.2 ± 2.2%).…”