Selection of autolytic lactic acid bacteria as potential adjunct cultures to accelerate ripening of white-brined cheeses

Abstract

The aim of this study was to select lactic acid bacteria (LAB) having autolytic activity on the basis of the technological aspects to accelerate the ripening of white-brined cheeses. For this purpose, mesophilic (n=526) and thermophilic (n=413) LAB isolates were collected from 34 raw milk and 16 cheese samples. 27 LAB isolates with a high autolytic activity ranging from 34 to 54 % were identified by (GTG) 5 fingerprint and 16S rDNA sequence analyses, which showed that Lactococcus lactis and Enterococcus faecium were abundant among the autolytic isolates in raw milk while E. faecium and Lactobacillus casei were in white-brined cheese. The autolysis rate of LAB strains increased by raising the temperature and pH; however, decreased somewhat at high NaCl concentrations. Additionally, the highest autolysis was observed in the presence of glucose for most of the strains. On the other hand, Lb. plantarum PFC231 was autolyzed differently, being the highest in the presence of lactose. E. durans PFC235, E. faecium PFC232 and Lb. plantarum PFC231 were autolyzed more than other LAB strains, when exposed to low pH, high NaCI concentration at 10 °C simultaneously. However, only Lb. plantarum PFC231, Leuconostoc mesenteroides PFC234, Lc. lactis subsp. cremoris PFC233, Pediococcus acidilactici PFC237 and Lb. rhamnosus PFC238 were able to show intracellular caseinolytic activity. In conclusion, Lb. plantarum PFC231 has the potential to be used as an adjunct starter culture in the production of white-brined cheeses because of its autolysis at low temperature, pH and high salt concentrations, as well as intracellular caseinolytic activity.

Is Acrylamide as Harmful as We Think? A New Look at the Impact of Acrylamide on the Viability of Beneficial Intestinal Bacteria of the Genus Lactobacillus

“…Moreover, some dead cells underwent autolysis, and the cell content released in the medium was utilized by survivors. Lactic acid bacteria are characterized by differentiated autolytic activity, but the process allows them to eliminate weak or impaired cells from the population [56]. In the mentioned study, L. plantarum strains were autolyzed more than other LAB strains; however, the authors did not test the autolytic activity of L. brevis or L. acidophilus [56].…”

“…In the mentioned study, L. plantarum strains were autolyzed more than other LAB strains; however, the authors did not test the autolytic activity of L. brevis or L. acidophilus [56]. It is well known that some lactic acid bacteria can undergo enzymatic cleavage of cell wall peptidoglycans by peptidoglycan hydrolases present in the bacterial cells and that the autolysis depends on factors, such as carbon source, temperature, osmotic concentration, and pH [56]. It has also been demonstrated that N-acetylmuramidase has a critical function in Lactobacillus bulgaricus autolysis [57] as one of the major degraders of the cell wall.…”

“…Lactic acid bacteria are characterized by differentiated autolytic activity, but the process allows them to eliminate weak or impaired cells from the population [56]. In the mentioned study, L. plantarum strains were autolyzed more than other LAB strains; however, the authors did not test the autolytic activity of L. brevis or L. acidophilus [56]. It is well known that some lactic acid bacteria can undergo enzymatic cleavage of cell wall peptidoglycans by peptidoglycan hydrolases present in the bacterial cells and that the autolysis depends on factors, such as carbon source, temperature, osmotic concentration, and pH [56].…”

Analysis of the kefir and koumiss microbiota with the focus on certain functional properties of selected lactic acid bacteria

“…It is one of the main desirable characteristics of lactic acid bacteria, especially used as starter cultures, to produce lactic acid and maintain their viability in acidic environment (Leboš Pavunc et al, 2013;Hazır Dalca et al, 2018). Lactic acid bacteria are able to survive in high-acid foods without significant losses in the number of viable microorganisms (Liu et al, 2011).…”