Soy milk-based microspheres as potential carriers for the protection of Enterococcus faecalis HZNU P2

Consortium of selected yeasts to produce healthy soy fermented beverage: Evaluation of microbial evolution, analytical, sensorial, and functional features

Currently, an increasing number of intolerant and vegan consumers are driving the market towards plant-based milk alternatives. Here, selected probiotic yeasts, belonging to the Candida zeylanoides, Kluyveromyces lactis and Debaryomyces hansenii species, previously characterized for their aptitude to ferment animal milk, were tested in soy milk. Trials at different fermentation times with the developed yeast consortium (Yc) coinoculated with a lactic bacterium commercial strain were carried out. Yc showed good fermentation performance, conferring distinctive analytical and aromatic properties to the resulted soy fermented beverage, a product similar to an industrial kefir. Analytical determinations did not show significant variations between the end of fermentation and cold storage (4 weeks at 4 °C), indicating full stability. Phenol amounts and antioxidant activity were significantly increased in soy fermented beverage fermented by Yc. All yeasts remained viable until the end of storage with a final concentration of approximately 8 Log CFU/ml, a value suitable for a probiotic commercial claim. Overall, the results suggest that Yc is a promising multistarter candidate for functional soy products.

Effects of Lactobacillus reuteri and Streptomyces coelicolor on Growth Performance of Broiler Chickens

There are well documented complications associated with the continuous use of antibiotics in the poultry industry. Over the past few decades, probiotics have emerged as viable alternatives to antibiotics; however, most of these candidate probiotic microorganisms have not been fully evaluated for their effectiveness as potential probiotics for poultry. Recent evaluation of a metagenome of broiler chickens in our laboratory revealed a prevalence of Lactobacillus reuteri (L. reuteri) and Actinobacteria class of bacteria in their gastrointestinal tract. In this study Lactobacillus reuteri and Streptomyces coelicolor (S. coelicolor) were selected as probiotic bacteria, encapsulated, and added into broiler feed at a concentration of 100 mg/kg of feed. In an 8-week study, 240 one day-old chicks were randomly assigned to four dietary treatments. Three dietary treatments contained two probiotic bacteria in three different proportions (L. reuteri and S. coelicolor individually at 100 ppm, and mixture of L. reuteri and S. coelicolor at 50 ppm each). The fourth treatment had no probiotic bacteria and it functioned as the control diet. L. reuteri and S. coelicolor were added to the feed by using wheat middlings as a carrier at a concentration of 100 ppm (100 mg/kg). Chickens fed diets containing L. reuteri and S. coelicolor mixture showed 2% improvement in body weight gain, 7% decrease in feed consumption, and 6–7% decrease in feed conversion ratios. This research suggests that L. reuteri and S. coelicolor have the potential to constitute probiotics in chickens combined or separately, depending on the desired selection of performance index.

Encapsulating Viability of Multi-strain Lactobacilli as Potential Probiotic in Pigs

Important aspects of the selection of probiotics to be used for mixing in animal feed include host species specificity and probiotic cell survival during production and storage of their products. The research was to screen and investigate some probiotic properties of lactic acid bacteria (LAB) isolated from pig fecal samples. One hundred and thirty-eight representative LAB isolates, which were isolated from 51 pig fecal samples, were tested for acid and bile tolerance, antimicrobial susceptibility, antibacterial activity, potential adhesion to the cell surface, and survival rates when stored in varied microencapsulation forms: freeze-dried, spray-dried, and micro-beads. The antibacterial activity results of the ten LAB isolates, which were acid- (pH 2, 3 h) and bile- (50% (v/v) fresh pig bile, 8 h) tolerant and suitable for resisting the five antibiotics commonly used for treating pig infections with pathogenic indicator strains, showed that three isolates (L21, L80, L103) had strong inhibition to Escherichia coli, Salmonella group B, and Salmonella group D using co-culturing and agar spot assays. The three isolates had high hydrophobicity (65-73%) and did not show antagonistic growth against each other. All three selected isolates had greater than 80% survival in freeze-dried and micro-bead forms at 25-30 °C after 2 days of storage (80.4-86.75%, 7.31-7.89 log CFU/ml). Sequence analysis of the 16S rRNA genes demonstrated that the three isolates belong to Lactobacillus plantarum (strain L21 and strain L80) and L. paraplantarum (strain L103). The single and multiple strains of these bacteria may have potential use as probiotics in pig diets.