Enzymatic activity of Lactobacillus reuteri grown in a sweet potato based medium with the addition of metal ions

Bigel Matrix Loaded with Probiotic Bacteria and Prebiotic Dietary Fibers from Berry Pomace Suitable for the Development of Probiotic Butter Spread Product

This study presents a novel approach to developing a probiotic butter spread product. We evaluated the prebiotic activity of soluble dietary fibers extracted from cranberry and sea buckthorn berry pomace with different probiotic strains (Limosilactobacillus reuteri, Lacticaseibacillus paracasei, and Lactiplantibacillus plantarum), uploaded selected compatible combination in the bigel matrix, and applied it in the probiotic butter spread formulation. Bigels and products were characterized by physical stability, rheological, textural properties, and viability of probiotics during storage at different conditions. The highest prebiotic activity score was observed in soluble cranberry (1.214 ± 0.029) and sea buckthorn (1.035 ± 0.009) fibers when cultivated with L. reuteri. The bigels loaded with probiotics and prebiotic fiber exhibited a significant increase in viscosity (higher consistency coefficient 40-45 Pa·sn) and better probiotic viability (>6 log CFU/g) during long-term storage at +4 °C temperature, surpassing the bigels loaded with probiotics alone. Bigels stored at a lower temperature (-18 °C) maintained high bacterial viability (above 8.5 log CFU/g). The butter spread enriched with the bigel matrix was softer (7.6-14.2 N), indicating improved spreadability. The butter spread product consistently met the required 6 log CFU/g for a functional probiotic food product until 60 days of storage at +4 °C temperature. The butter stored at -18 °C remained probiotic throughout the entire storage period, confirming the protective effect of the bigel matrix. The study's results showed the potential of the bigel to co-encapsulate, protect, and deliver probiotics during prolonged storage under different conditions.

Conversion of Phenolic Acids in Canola Fermentation: Impact on Antimicrobial Activity against Salmonella enterica and Campylobacter jejuni

Canola meal (CM) is commonly used in poultry feeds. CM has a high protein content but also contains high levels of antimicrobial phenolic acids. Lactic acid bacteria can alter CM phenolic composition during fermentation and influence its antimicrobial activity against pathogens. Fermented CM was analyzed for phenolic composition using tandem mass spectrometry (LC-MS/MS) and high-performance liquid chromatography (HPLC). Sinapic acid and derivatives were the major phenolic acids in CM. Growth of lactobacilli in CM was attenuated when compared to cereal substrates. Glucosides and esters of sinapic acid were extensively hydrolyzed during fermentation with Lactiplantibacillus plantarum and Furfurilactobacillus milii. Lp. plantarum transformed hydroxycinnamic acids to dihydro, 4-vinyl, and 4-ethyl derivatives, Ff. milii reduced hydroxycinnamic acids to dihydroderivatives, but Limosilactobacillus reuteri did not convert hydroxycinnamic acids. The minimum inhibitory concentration of phenolic extracts was assessed with lactobacilli, Salmonella, and Campylobacter jejuni as indicator strains. Fermentation of CM with Lp. plantarum or Ff. milii increased the antimicrobial activity of phenolic extracts against Salmonella enterica and Campylobacter jejuni. Fermentation with Lm. reuteri TMW1.656 but not fermentation with Lm. reuteri TMW1.656ΔrtcN increased the antimicrobial activity of extracts owing to the production of reutericyclin. This study demonstrates that fermentation of CM with lactobacilli converts hydroxycinammic esters and may increase the antimicrobial activity of phenolic compounds in CM against pathogens.

Effects of calcium level and source, formic acid, and phytase on phytate degradation and the microbiota in the digestive tract of broiler chickens

BACKGROUND

Diet acidification, dietary calcium (Ca) level, and phytase supplementation are known influences on the microbial community in the digestive tract and on phosphorus (P) utilization of broiler chickens. Effects of dietary factors and microbiota on P utilization may be linked because microorganisms produce enzymes that release P from phytate (InsP6), the main source of P in plant feedstuffs. This study aimed to detect linkages between microbiota and InsP6 degradation by acidifying diets (i.e., replacing Ca carbonate (CaCO3) by Ca formate or adding formic acid to CaCO3-containing diets), varying Ca levels, and supplementing phytase in a three-factorial design. We investigated i) the microbial community and pH in the digestive tract, ii) prececal (pc) P and Ca digestibility, and iii) InsP6 degradation.

RESULTS

All factors under investigation influenced digesta pH and the microbiota composition. Predicted functionality and relative abundance of microorganisms indicated that diets influenced the potential contribution of the microbiota on InsP degradation. Values of InsP6 degradation and relative abundance of the strains Lactobacillus johnsonii and Lactobacillus reuteri were correlated. Phytase supplementation increased pc InsP6 disappearance, with differences between Ca levels, and influenced concentrations of lower inositol phosphate isomers in the digestive tract. Formic acid supplementation increased pc InsP6 degradation to myo-inositol. Replacing CaCO3 by Ca-formate and the high level of these Ca sources reduced pc InsP6 disappearance, except when the combination of CaCO3 + formic acid was used. Supplementing phytase to CaCO3 + formic acid led to the highest InsP6 disappearance (52%) in the crop and increased myo-inositol concentration in the ileum digesta. Supplementing phytase leveled the effect of high Ca content on pc InsP6 disappearance.

CONCLUSIONS

The results point towards a contribution of changing microbial community on InsP6 degradation in the crop and up to the terminal ileum. This is indicated by relationships between InsP6 degradation and relative abundance of phosphatase-producing strains. Functional predictions supported influences of microbiota on InsP6 degradation. The extent of such effects remains to be clarified. InsP6 degradation may also be influenced by variation of pH caused by dietary concentration and solubility of the Ca in the feed.

Hydrolysis of sweet potato (Ipomoea batatas (L.) Lam.) flour by Candida homilentoma strains: effects of pH and temperature using Central Composite Rotatable Design

The current study focuses on the evaluation of culture parameters on the enzymatic hydrolysis of Ipomoea batatas (L.) Lam flour by Candida homilentoma strains. A 2-factor-5-level CCRD was used to evaluate the effect of pH and temperature on the hydrolysis process. For the S-47 strain, pH and both studied parameters were significant at 48 h and 96 h, respectively. Regarding S-81 strain, temperature was the only factor affecting the process, at 96 hours. The regression models were significant, and no lack of fit was observed for them.

Effect of carvacrol essential oils on growth performance and intestinal barrier function in broilers with lipopolysaccharide challenge

The purpose of this study was to evaluate the effects of orally administrated carvacrol essential oils (CEOs) on the function of the intestinal barrier in broilers challenged by lipopolysaccharide (LPS). Eighty 28-day-old Ross 308 broilers were assigned to a 2 × 2 factorial arrangement of treatments (20 pens of 1 chick/treatment). Factors were CEOs (with or without orally administered) and LPS (challenged or non-challenged). Individually housed broilers were randomly assigned to four treatments (n = 20 broilers per treatment: 10 males and 10 females): no CEOs and no LPS challenge (NCEOs + NLPS); CEOs and no LPS challenge (CEOs + NLPS); no CEOs and LPS challenge (NCEOs + LPS); CEOs and LPS challenge (CEOs + LPS); all birds were fed the same diet. The broilers were administered 200 μL CEOs daily for 15 days. Orally administered CEOs significantly (P < 0.05) increased the gene expressions of occludin, claudin-1, claudin-5, zonula occludens-1 (ZO-1) and ZO-2 in the small intestinal mucosa, and increased (P < 0.05) the counts of goblet cell in the small intestinal epithelium; LPS-challenge damaged the intestinal barrier, and significantly (P < 0.05) reduced the gene expression of the aforementioned genes and increased the Escherichia coli (P < 0.05) and Salmonella enumeration (P < 0.05) in the intestine of broilers compared with the NCEOs + NLPS group. Injecting LPS reduced (P < 0.05) the gene expression of sIgA compared with the NCEOs + NLPS group. In summary, the CEOs improved the development of the intestinal barrier, to a certain extent, and repaired the intestinal damage caused by LPS.

In vitro assessment of metabolic profile of Enterococcus strains of human origin

Background

In the present study, previously isolated, safe, and avirulent enterococci strains were exploited for their metabolic profile (Bhagwat et al., Asian J Pharm Clin Res 12: 2019).

Results

Thirteen enterococci strains of human origin produced important enzymes like amylase (0.5–0.7 mg ml⁻¹), protease (192–264 mg ml⁻¹), lipase (8–10 mg ml⁻¹), bile salt hydrolase, conjugated linoleic acid (CLA), and lactic acid (highest 12 mg ml⁻¹), thus implicating potential attributes of starter cultures in food and dairy industry. Biogenic amines like arginine and tryptamine were produced after 4 days above 25 °C. Castor oil (highest yield 60 μg ml⁻¹) and sunflower oil (highest yield 48 μg ml⁻¹) both proved to be excellent sources of CLA production. Reduction assays using FRAP, ABTS (above 83%), and DPPH (30–50%) revealed excellent radical scavenging properties of cell-free supernatants of Enterococcus strains.

Conclusion

The results implicate the future potential of application enterococci for therapeutic purpose as well as the food industry.

Effects of oral administration of different dosages of carvacrol essential oils on intestinal barrier function in broilers

Essential oils are widely used in the pharmaceutical, food and cosmetic industries, and many plant essential oils have shown that they have positive effects on broilers nutrition. This experiment was conducted to study the effects of orally administered different dosages of carvacrol essential oils on intestinal barrier function in broiler chickens. A total of eighty 28-day-old (1.28 ± 0.15 kg) ROSS 308 broilers were randomly allocated to four groups of 20 replicates each, with one chicken per replicate per cage, and all were fed with the same diet. Four experimental groups were orally administered 0, 200, 300 or 400 μl carvacrol essential oils at 18:00 hr every day during the 2-week experimental period. As a result of which, the gene expression of the occludin, claudin-1, claudin-5, ZO-1 and ZO-2 in intestinal mucosa of small intestine (p < 0.05) and the goblet cell content in small intestine epithelium (p < 0.05) were significantly increased; test subjects with 300 or 400 μl carvacrol essential oils reduced the microbial counts of Salmonella spp. and Escherichia coli in the intestines (p < 0.05); Essential oils administration also significantly increased activity of the sucrase (p < 0.05) and lactase (p < 0.05) in intestinal mucosa. In conclusion, the carvacrol essential oils have positive effects on growth performance and intestinal barriers function of broilers; those effects may be related to the dosage, as administration of 300 or 400 μl was more effective than that of 200 μl.

Purification and characterization of a novel cold-adapted phytase from Rhodotorula mucilaginosa strain JMUY14 isolated from Antarctic

A yeast producing a cold-adapted phytase was isolated from Antarctic deep-sea sediment and identified as a Rhodotorula mucilaginosa strain JMUY14 of basidiomycetous yeasts. It was cultured in fermentation optimized by a response surface methodology based on the Box-Behnken design. The maximum activity of phytase reached 205.447 U ml(-1), which was close to the predicted value of 201.948 U ml(-1) and approximately 3.4 times higher than its initial activity. The extracellular phytase was purified by 15.2-fold to homogeneity with a specific activity of 31,635 U mg(-1) by (NH4 )2 SO4 precipitation, and a combination of DEAE Sepharose Fast Flow, SP Sepharose Fast Flow, and Sephadex G-100. The molecular weight of the purified enzyme was estimated to be 63 kDa and its pI was 4.33. Its optimal temperature and pH were 50 °C and 5.0, respectively. Its activity was 85% at 37 °C, and showed good stability at pH 3.0 ∼ 7.0. When compared with mesophilic counterparts, the phytase not only exhibited a higher activity during 20 ∼ 30 °C but also had a low Km (247 µM) and high kcat (1394 s(-1)). The phytase activity was slightly stimulated in the presence of Mg(2+), Fe(2+), Fe(3+), K(+), Na(+), Ca(2+), EDTA, and EGTA and moderately inhibited by Cu(2+), Zn(2+), Mn(2+), Ag(+), PMSF, SDS, and phenylgloxal hydrate. It was resistant to both pepsin and trypsin. Since the phytase produced by the R. mucilaginosa JMUY14 showed a high specific activity, good pH stability, strong protease resistance, and high activity at low temperature, it has great potential for feed applications, especially in aquaculture.