Phytase Activity from Lactobacillus spp. in Calcium-Fortified Soymilk

Functional relevance and health benefits of soymilk fermented by lactic acid bacteria

The growing interest of consumers towards nutritionally enriched, and health promoting foods, provoke interest in the eventual development of fermented functional foods. Soymilk is a growing trend that can serve as a low-cost non-dairy alternative with improved functional and nutritional properties. Soymilk acts as a good nutrition media for the growth and proliferation of the micro-organism as well as for their bioactivities. The bioactive compounds produced by fermentation of soymilk with lactic acid bacteria (LAB) exhibit enhanced nutritional values, and several improved health benefits including antihypertensive, antioxidant, antidiabetic, anticancer and hypocholesterolaemic effects. The fermented soymilk is acquiring a significant position in the functional food industry due to its increased techno-functional qualities as well as ensuring the survivability of probiotic bacteria producing diverse metabolites. This review covers the important benefits conferred by the consumption of soymilk fermented by LAB producing bioactive compounds. It provides a holistic approach to obtain existing knowledge on the biofunctional attributes of fermented soymilk, with a focus on the functionality of soymilk fermented by LAB.

Design and Characterization of a Novel Fermented Beverage from Lentil Grains

The experimental activities carried out in this study aimed at designing a lentil-based beverage rich in soluble and digestible proteins. In order to extract soluble proteins, lentil grains were soaked in water overnight, blended, treated with proteolytic enzymes and fermented with Lactobacillus strains. Protein enzymatic hydrolysis, carried out with four commercial food grade enzyme preparations, showed that bromelin, at the enzyme to substrate ratio of 10%, was the best solution to produce this novel beverage. Even though the seven Lactobacillus strains were all able to ferment aqueous extract within 24 h, L. acidophilus ATCC 4356, L. fermentum DSM 20052 and L. paracasei subsp. paracasei DSM 20312 showed the highest growth rate and the lowest pH values. In fermented lentil-based beverages, the antinutritional factor phytic acid decreased up to 30%, similarly, the highest reduction in raffinose oligosaccharides content reached about 12% the initial concentration. It is worthy of note that the viable density of all strains remained higher than 7 log cfu/mL after 28 days of cold storage. The results here reported show for the first time the possibility to obtain a probiotic lentil-based beverage rich in soluble proteins, peptides and amino acids with low content in main antinutritional factors.

The functional and organoleptic characterization of a dairy-free dessert containing a novel probiotic food ingredient

New eating habits and diversification of tastes in consumers have led to the scientific community and the food industry expanding the range of probiotic foods and novel probiotic ingredients.

Expression of bifidobacterial phytases in Lactobacillus casei and their application in a food model of whole-grain sourdough bread

Phytases are enzymes capable of sequentially dephosphorylating phytic acid to products of lower chelating capacity and higher solubility, abolishing its inhibitory effect on intestinal mineral absorption. Genetic constructions were made for expressing two phytases from bifidobacteria in Lactobacillus casei under the control of a nisin-inducible promoter. L. casei was able of producing, exporting and anchoring to the cell wall the phytase of Bifidobacterium pseudocatenulatum. The phytase from Bifidobacterium longum spp. infantis was also produced, although at low levels. L. casei expressing any of these phytases completely degraded phytic acid (2mM) to lower myo-inositol phosphates when grown in MRS medium. Owing to the general absence of phytase activity in lactobacilli and to the high phytate content of whole grains, the constructed L. casei strains were applied as starter in a bread making process using whole-grain flour. L. casei developed in sourdoughs by fermenting the existing carbohydrates giving place to an acidification. In this food model system the contribution of L. casei strains expressing phytases to phytate hydrolysis was low, and the phytate degradation was mainly produced by activation of the cereal endogenous phytase as a consequence of the drop in pH. This work shows the capacity of lactobacilli to be modified in order to produce enzymes with relevance in food technology processes. The ability of these strains in reducing the phytate content in fermented food products must be evaluated in further models.

Reduction of Phytate in Soy Drink by Fermentation with Lactobacillus casei Expressing Phytases From Bifidobacteria

Plant-based food products can be modified by fermentation to improve flavour and the concentration of some biologically active compounds, but also to increase the mineral availability by eliminating anti-nutrient substances such as phytates. The objective of this study was to develop a fermented soybean drink with improved nutritional quality and source of probiotic bacteria by including as starter for fermentation Lactobacillus casei strains modified to produce phytase enzymes from bifidobacteria. The L. casei strains showed a good adaptation to develop in the soy drink but they needed the addition of external carbohydrates to give rise to an efficient acidification. The strain expressing the Bifidobacterium pseudocatenulatum phytase was able to degrade more than 90 % phytate during product fermentation, whereas expression of Bifidobacterium longum spp. infantis phytase only led to 65 % hydrolysis. In both cases, accumulation of myo-inositol triphosphates was observed. In addition, the hydrolysis of phytate in soy drink fermented with the L. casei strain expressing the B. pseudocatenulatum phytase resulted in phytate/mineral ratios for Fe (0.35) and Zn (2.4), which were below the critical values for reduced mineral bioavailability in humans. This investigation showed the ability of modified L. casei to produce enzymes with technological relevance in the design of new functional foods.

Effect of sequential bio-processing conditions on the content and composition of vitamin K2 and isoflavones in fermented soy food

In the present research, effect of sequential addition of Bifidobacterium bifidum, Bacillus subtilis and Rhizopus oligosporus on content and composition of vitamin K2 and isoflavones in fermented soy foods have been investigated. Initially, soybeans were fermented with B. bifidum; then this fermented mass was re-fermented with co-culture of B. subtilis and R. oligosporus. The evolved sequence of microbes inoculation tended towards significantly (p < 0.5) higher enzymes levels (126.16 ± 2.23 IU/mg lipase, 36.52 ± 1.25 IU/mg phytase and 8.52 ± 1.12 IU/mg β-glucosidase); maximum menaquinone-7 production (9.3 ± 1.27 μg/g); and isoflavone content (84.64 ± 1.97 % daidzein, 99.29 ± 0.86 % genistein, 96.42 ± 1.32 % glycitein) after 72 h of solid-state fermentation. The study showed that co-fermentation of soybean with different microbes in a particular sequence can enhance nutritional value batter than the mono-culture fermentation due to the positive correlation between enzymes (lipase, phytase, β-glucosidase) levels, menaquinone-7 and soy isoflavones content.

Evaluation of phytate-degrading Lactobacillus culture administration to broiler chickens

Probiotics have been demonstrated to promote growth, stimulate immune responses, and improve food safety of poultry. While widely used, their effectiveness is mixed, and the mechanisms through which they contribute to poultry production are not well understood. Microbial phytases are increasingly supplemented in feed to improve digestibility and reduce antinutritive effects of phytate. The microbial origin of these exogenous enzymes suggests a potentially important mechanism of probiotic functionality. We investigated phytate degradation as a novel probiotic mechanism using recombinant Lactobacillus cultures expressing Bacillus subtilis phytase. B. subtilis phyA was codon optimized for expression in Lactobacillus and cloned into the expression vector pTRK882. The resulting plasmid, pTD003, was transformed into Lactobacillus acidophilus, Lactobacillus gallinarum, and Lactobacillus gasseri. SDS-PAGE revealed a protein in the culture supernatants of Lactobacillus pTD003 transformants with a molecular weight similar to that of the B. subtilis phytase. Expression of B. subtilis phytase increased phytate degradation of L. acidophilus, L. gasseri, and L. gallinarum approximately 4-, 10-, and 18-fold over the background activity of empty-vector transformants, respectively. Phytase-expressing L. gallinarum and L. gasseri were administered to broiler chicks fed a phosphorus-deficient diet. Phytase-expressing L. gasseri improved weight gain of broiler chickens to a level comparable to that for chickens fed a control diet adequate in phosphorus, demonstrating proof of principle that administration of phytate-degrading probiotic cultures can improve performance of livestock animals. This will inform future studies investigating whether probiotic cultures are able to provide both the performance benefits of feed enzymes and the animal health and food safety benefits traditionally associated with probiotics.

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

The effect of metal ions on the enzymatic activity of Lactobacillus reuteri was studied. The enzymatic activity was determined spectrophotometrically using the corresponding substrate. In the control group, L. reuteri MF14-C, MM2-3, SD2112, and DSM20016 produced the highest α-glucosidase (40.06 ± 2.80 Glu U/mL), β-glucosidase (17.82 ± 1.45 Glu U/mL), acid phosphatase (20.55 ± 0.74 Ph U/mL), and phytase (0.90 ± 0.05 Ph U/mL) respectively. The addition of Mg(2+) and Mn(2+) led to enhance α-glucosidase produced by L. reuteri MM2-3 by 113.6% and 100.6% respectively. α-Glucosidase produced by MF14-C and CF2-7F was decrease in the presence of K(+) by 65.8 and 69.4% respectively. β-Glucosidase activity of MM7 and SD2112 increased in the presence of Ca(2+) (by 121.8 and 129.8%) and Fe(2+) (by 143.9 and 126.7%) respectively. Acid phosphatase produced by L. reuteri CF2-7F and MM2-3 was enhanced in the presence of Mg(2+), Ca(2+) or Mn(2+) by (94.7, 43.2, and 70.1%) and (63.1, 67.8, and 45.6%) respectively. On the other hand, Fe(2+), K(+), and Na(+) caused only slight increase or decrease in acid phosphatase activity. Phytase produced by L. reuteri MM2-3 was increase in the presence of Mg(2+) and Mn(2+) by 51.0 and 74.5% respectively. Ca(2+) enhanced phytase activity of MM2-3 and DSM20016 by 27.5 and 28.9% respectively. The addition of Na(+) or Fe(2+) decreased phytase activity of L. reuteri. On average, Mg(2+) and Mn(2+) followed by Ca(2+) led to the highest enhancement of the tested enzymes. However, the effect of each metal ion on the enzymatic activity of L. reuteri was found to be a strain dependent. Therefore, a maximized level of a target enzyme could be achieved by selecting a combination of specific strain and specific metal ion.

Characterization and application of calcium-dependent β-propeller phytase from Bacillus amyloliquefaciens DS11

The enzyme phytase has broad biotechnological applications, especially in the reduction of phytate, antinutritional factors that chelate essential minerals, in human and animal food. We investigated the enzymatic properties of β-propeller phytase (BPP) from Bacillus amyloliquefaciens DS11. Thermal refolding analysis demonstrated that BPP can remarkably restore its enzymatic activity in the presence of 5 mM Ca(2+) to 87% of its original activity after heating to 100 °C and subsequent cooling, indicating that the enzyme requires Ca(2+) for appropriate refolding. Furthermore, pH-dependent kinetic studies showed that BPP required excess Ca(2+) for its enzymatic activity as the pH decreased, suggesting that the optimal Ca(2+)-phytate ratio for enzymatic catalysis depends on the pH value of the environment. Finally, we verified the practical application of BPP at two different pH's using soybean meal as a natural source of phytate. As compared to a commercial phytase, BPP efficiently hydrolyzed food phytate over neutral pH ranges.

Effect of dietary inulin and phytase on mineral digestibility and tissue retention in weanling and growing swine

The effect of dietary phytase and the prebiotic inulin on apparent mineral digestibility, bone mineralization, and tissue mineral contents was evaluated in weanling and growing pigs. In Exp. 1, inulin and phytase were incorporated in a 2 × 3 factorial arrangement of treatments with 8 replicate pens per treatment in a randomized complete block design. There were 2 levels of phytase [0 and 1000 phytase units (FTU)/kg] and 3 levels of chicory inulin (0, 3, and 6%). Weanling pigs (17 d of age; 5 or 4 pigs per pen) with an initial BW of 6.0 ± 0.6 kg were evaluated for 35 d postweaning. Macromineral digestibility was calculated using chromic oxide as an index in fecal samples collected during the final week of the experiment in replicates 1 through 4. On d 36, 1 pig per pen was killed and the heart, liver, kidney, and left tibia were excised and weighed. Inulin did not have any effect on growth performance measurements. Phytase increased (P < 0.05) BW on d 35 and ADG and ADFI during the 21-to-35-d and 0-to-35-d periods. Inulin did not result in increased tissue mineral concentrations on a per unit (mg/kg) or total tissue basis. Phytase increased (P < 0.05) the concentration of Zn in the liver, Mn and Zn in the heart, and Mg and Mn in the kidney. Phytase also increased (P < 0.05) total P, Mg, S, Mn, Se, and Zn in the liver as well as tibia ash. Phytase increased the digestibility of Ca (P < 0.01) and P (P < 0.05). Experiment 2 was conducted with growing pigs (initial BW, 41 ± 5 kg) to evaluate 2 levels of inulin (0 or 6%) and 2 levels of phytase (0 or 1000 FTU/kg) in a 2 × 2 factorial with 6 replicates in a randomized complete block design. Total urine and feces were collected for 10 d from each of 24 barrows after a 21-d acclimation period. Inulin inclusion resulted in reduced Ca digestibility (P < 0.05). Phytase increased (P < 0.05) the digestibility of both Ca and P. These results indicate that dietary inulin does not affect the overall mineral status or growth performance of pigs, whereas phytase increases the utilization of Ca and several microminerals, in addition to P, and also increases growth performance. Inulin and phytase do not appear to interact to affect pig growth or mineral status.