Probiotic bacteria survive in Cheddar cheese and modify populations of other lactic acid bacteria

Abstract

Aims: Starter lactic acid bacteria in Cheddar cheese face physico-chemical stresses during manufacture and ageing that alter their abilities to survive and to interact with other bacterial populations. Nonstarter bacteria are derived from milk handling, cheese equipment and human contact during manufacture. Probiotic bacteria are added to foods for human health benefits that also encounter physiological stresses and microbial competition that may mitigate their survival during ageing. We added probiotic Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus paracasei and Bifidobacterium animalis subsp. lactis to full-fat, reduced-fat and low-fat Cheddar cheeses, aiming to study their survival over 270 days of ageing and to determine the role of the cheese matrix in their survival. Methods and Results: Probiotic and other lactic acid bacterial populations were enumerated by quantitative PCR using primers specifically targeting the different bacterial genera or species of interest. Bifidobacteria were initially added at 10 6 CFU g À1 cheese and survived variably in the different cheeses over the 270-day ageing process. Probiotic lactobacilli that were added at 10 7 CFU g À1 cheese and incident nonstarter lactobacilli (initially at 10 8 CFU g À1 cheese) increased by 10-to 100-fold over 270 days. Viable bacterial populations were differentiated using propidium monoazide followed by species-specific qPCR assays, which demonstrated that the starter and probiotic microbes survived over ageing, independent of cheese type. Addition of probiotic bacteria, at levels 100-fold below that of starter bacteria, modified starter and nonstarter bacterial levels. Conclusions: We demonstrated that starter lactococci, nonstarter lactobacilli and probiotic bacteria are capable of surviving throughout the cheesemaking and ageing process, indicating that delivery via hard cheeses is possible. Probiotic addition at lower levels may also alter starter and nonstarter bacterial survival. Significance and Impact of the Study: We applied qPCR to study multispecies survival and viability and distinctly enumerated bacterial species in commercial-scale Cheddar cheese manufacture.

Survival of potential probiotic lactobacilli used as adjunct cultures on Pecorino Siciliano cheese ripening and passage through the gastrointestinal tract of healthy volunteers

“…Although numerous studies have already been published on different cheese types containing probiotic strains (Ganesan et al, 2014;Gobbetti et al, 1997) no information on…”

Physicochemical, microbiological and spoilage analysis of probiotic processed cheese analogues with reduced emulsifying salts during refrigerated storage

“…Probiotics or living micro-organisms which upon ingestion in certain numbers exert health benefits beyond inherent basic nutrition have numerous health benefits such as enhanced immune response, alleviation of symptoms of lactose intolerance, treatment of diarrhea, reduction of serum cholesterol, vitamin synthesis and anti-carcinogenic and anti-microbial activities (Shah 2007;Ganesan et al 2014b;Salari et al 2015;Shokoohi et al 2015;Torkamani et al 2015). Meanwhile, probiotic bacteria such as Bifidobacterium longum, Bif.…”

The potential use of probiotic strains Lactobacillus acidophilus NRRL B 4495, Bifidobacterium bifidum NRRL B41410 in “Lor Whey Cheese” and the effects on sensory properties

“…Ganesan et al (2014) reported that starter lactococci, nonstarter lactobacilli and probiotic bacteria are capable of surviving the Cheddar cheese making and ageing process. Miocinovic et al (2014) found low-fat UF cheese represents a good vehicle for probiotic bacteria, which maintains satisfactory viability throughout the ripening process.…”

“…animalis numbers in whey cheese increased to 8.59 from 7.97 log cfu/g after 21 days of storage. Ganesan et al (2014) explained that survival of bifidobacterial species in even one cheese type may change. The variations in fat levels and physico-chemical conditions inside the cheese matrices can alter the viability of a given strain of bacteria.…”

“…bifidum of 10 6 -10 7 cfu/g, which is the optimum level recommended to provide therapeutic benefits (Phillips et al, 2006). Ganesan et al (2014) explained that, when adjunct or probiotic bacteria are included in the cheese matrix, the balance of LAB populations can be altered because of the competition for nutritional components between the microorganisms. Madureira et al (2011) determined that the use of probiotic strains like Bf.…”