Encapsulation of Lactobacillus plantarum ATCC 8014 and Pediococcus acidilactici ATCC 8042 in a freeze-dried alginate-gum arabic system and its in vitro testing under gastrointestinal conditions.

The aim of this study was to investigate the viability of Pediococcus acidilactici ATCC 8042 and Lactobacillus plantarum ATCC 8014 in a freeze-dried capsules system prepared with sodium alginate and gum arabic using the extrusion technique. The capsules made with alginate 2% (w/v)/gum arabic 2% (w/v) showed higher hardness (7.12 ± 0.71 N), with highly cohesive (0.81 ± 0.02) and elastic (0.99 ± 0.00) features on the Texture Profile Analysis (TPA), as well as higher sphericity with 1.75 ± 0.12 mm y 1.73 ± 0.13 mm diameter axes and regularity in their surface by Scanning Electron Microscopy (SEM). The use of skimmed milk at 10% as a cryoprotector in the freeze-drying process allowed the obtention of high viability percentages (88% a 96%) for both strains. Best results of viability for P. acidilactici encapsulated was with the use of alginate 2% (w/v)/gum arabic 2% (w/v) (92%±2.65), and L. plantarum with the use of alginate 2% (w/v) (84.71%±10.33) during the gastrointestinal environment challenge.

A novel endo-ß-1,4-xylanase from Pediococcus acidilactici GC25; purification, characterization and application in clarification of fruit juices.

A novel extracellular xylanase was purified and characterized from Pediococcus acidilactici GC25 (GenBank number: MF289522). The purification was 4.6-fold with a yield of 43.61% through acetone precipitation, Q-Sepharose, and CM-Sepharose ion change chromatography. The molecular weight of the enzyme was 48.15 kDa, and the optimum pH and temperature were 7.0 and 40 °C, respectively. The maximum activity was observed between 20 and 50 °C. Although it was active within a wide pH range (pH 2.0-9.0), it retained over 85% of its activity after 24 h incubation; and over 70% of its activity after 168 h incubation in neutral and alkaline pH. It was observed that the enzyme showed high stability with K+, Ba2+, Cd2+, Co2+, Sr2+, Mg2+, Ca2+, Al3+, Zn2+, and Ni2+ ions. The Km and Vmax for the xylanase were 3.10 mg mL-1 and 4.66 U/mg protein, respectively. It was determined that treatment of different fruit juices with P. acidilactici GC25 xylanase improved the clarification. The highest increase in the reducing sugar amount and decrease in the turbidity was 24.47 ±â€¯1.08 and 21.22 ±â€¯0.58 for peach juice at 0.15 U/mL enzyme concentration. These results showed that the xylanase purified from P. acidilactici GC25 may have a wide potential in biotechnological processes of the food and baking industry.

Pediococcus acidilactici strains as silage inoculants for improving the fermentation quality, nutritive value and in vitro ruminal digestibility in different forages.

AIMS: To examine the characteristics of three isolated Pediococcus acidilactici strains (LTG7, LOG9 and LH9) and evaluate their effects on silage quality, nutritive value and in vitro ruminal digestibility in a variety of forages. METHODS AND RESULTS: One commercial inoculant Lactobacillus plantarum MTD-1 (G) and three isolated lactic acid bacteria (LAB) strains were measured by morphological, physiological and biochemical tests. All the LAB strains were added to Italian ryegrass (Lolium multiflorum Lam.), tall fescue (Festuca arundinacea Schred.) and oat (Avena sativa L.) for ensiling 30 days in laboratory silos (1 l) respectively. Isolated strains could grow normally at 5-20°C, pH 3·5-7·0 and NaCl (3·0, 6·5%), and were identified as P. acidilactici by sequencing 16S rDNA. In Italian ryegrass and oat silages, all inoculants obviously (P < 0·05) increased lactic acid (LA) contents, LAB numbers and in vitro dry matter digestibility (IVDMD), and decreased pH, undesirable micro-organism numbers, butyric acid and ammonia nitrogen (NH3 -N) contents compared with the corresponding controls. LTG7, LOG9 and G silages in Italian ryegrass and oat had markedly (P < 0·05) higher LA content and IVDMD, and lower pH and NH3 -N contents than LH9 silages. In tall fescue silage, LAB inoculants had no obvious (P > 0·05) effect on fermentation quality, while markedly (P < 0·05) enhanced IVDMD. CONCLUSIONS: Based on our results, strains LTG7 and LOG9 had similar potential with the commercial inoculant G in silage making. SIGNIFICANCE AND IMPACT OF THE STUDY: Few studies involved inoculation of silage with P. acidilactici in different forage types. Analysis of effects of LAB strains with their physiological and biochemical characteristics help understand how LAB inoculants affect the digestibility.