Technological characterization of vaginal probiotic lactobacilli: resistance to osmotic stress and strains compatibility

Abstract

Aims The aim was to evaluate the osmotic stress resistance of vaginal beneficial probiotic strains, their growth kinetics and parameters when growing in salt‐added culture media, and their compatibility to go further in the design of a probiotic formula for reconstitution of vaginal microbiome in women. Methods and Results The resistance to osmotic stress of the lactobacilli was evaluated by determining their growth in MRS (as control) added with NaCl (2–8%). The most resistant strains were Lactobacillus gasseri CRL1509, L. rhamnosus CRL1332 and L. reuteri CRL1327 selected by statistical approaches and growth parameters. Electron microscopy was applied to determine changes. They maintain probiotic properties and viability. Some strains showed incompatibility, then they cannot be included in multistrain formulas. Conclusions The resistance to different salt concentrations in vaginal lactobacilli is strain‐specific, because the behaviour is different in strains identified into the same species. The resistance is not related to the metabolic groups. Significance and Impact of the Study The resistance and survival to extreme osmotic resistance is one of the specific requirements of beneficial bacteria after the technological processes for their inclusion in probiotic formulas, in a way to express their beneficial characteristics and exert the effect on the host.

Effect of simulated acidic and salty fermentation conditions on kinetic growth parameters and probiotic potential of Lactobacillus acidipiscis and Lactobacillus pentosus

“…1). Moreover, the biomass production (Figs 1 and 2) was declined by the presence of medium or high combined initial stress similarly to other studies (Silva et al, 2019). The initial low pH during the fermentation negatively affected the final production of biomass during the fermentation.…”

“…Technological stress increases the duration of the initial (lag) phase since bacteria must adapt to stressful conditions that affect the final time of fermentation, the biomass obtained, and the production of diverse metabolites (Yates & Smotzer, 2007). The accurate prediction of the lag phase duration is only possible through sigmoidal functions like the modified Gompertz equation and the Baranyi model (Silva et al, 2019). LAB with industrial potential should resist, survive, and grow under the conditions met during the processes in the shortest time possible.…”

Identification, Biochemical Characterization, and Safety Attributes of Locally Isolated Lactobacillus fermentum from Bubalus bubalis (buffalo) Milk as a Probiotic

“…were tested and are utilized to improve food quality and human nutrition [ 10 ]. However, Lactobacillus is the most common beneficial class of probiotics for various organisms [ 11 ] and is present in fermented dairy products such as yogurt, kefir, and buttermilk [ 12 , 13 ]. Due to the wide use of probiotics in fermentation, Lactobacillus is also added to other foods such as pickled vegetables, kimchi, pao cai, miso, and soy sauce [ 14 , 15 , 16 ].…”

Insight into phenotypic and genotypic differences between vaginal Lactobacillus crispatus BC5 and Lactobacillus gasseri BC12 to unravel nutritional and stress factors influencing their metabolic activity

“…Besides antibiotics and detergents, the research interest in the resistance/tolerance of vaginal Lactobacillus spp. strains to osmolytes and other toxic compounds such as metal(loid)s, can be associated to their possible therapeutical application as probiotics [64, 65, 73, 74]. In the PM assay, both BC12 and BC5 strains showed the capacity to resist/tolerate some of these toxic compounds and chemical stressors, despite the general higher performance of the L.…”