Aims: Probiotics are living microorganism, when administrated in sufficient quantity can exert beneficial effect to the host. This study focused on the microencapsulation by co-extrusion to increase the viability of Lactobacillus plantarum 299v (Lp299v) in gastrointestinal conditions, and its storage stability in kuini juice at refrigerated (4 °C) and ambient temperature (25 °C). Methodology and results: Lp99v was encapsulated with 1.5% w/v sodium alginate and chitosan coating (0.1% w/v) and yielded a microencapsulation efficiency of 97.71%. The Lp299v microbeads produced were spherical in shape and exhibited a mean microbeads size of 618.75 ± 25.85 µm. Acid and bile tolerance of both free and encapsulated Lp299v were tested in simulated gastric juice (SGJ) for 2 h and in simulated intestinal juice (SIJ) for 4 h, respectively. The encapsulated Lp299v maintained above 108 CFU/mL after exposure to artificial gastrointestinal juice, whereas a significant loss of viability was observed in the free cells. The storage stability of encapsulated Lp299v in kuini juice was determined during 4 weeks of storage at 4 °C and 25 °C. Results showed that encapsulated Lp299v was capable to remain viable (107 CFU/mL) for at least 4 weeks in a refrigerated condition. However, free Lp299v did not survived under both refrigerated and ambient temperature as the storage period extended. Conclusion, significance and impact of study Lp299v entrapped in chitosan-coated alginate microbeads produced by co-extrusion method is able to enhance the viability of Lp299v above the minimum recommended level in harsh environment (gastrointestinal conditions and low pH of kuini juice).
Cell Encapsulation ; Lactobacillus plantarum

In order to enrich the library of domestic research about new red fluorescent marker in lactic acid bacteria (LAB), we described a new fusion expression system in Lactobacillus plantarum WCFS1 based on the pSIP vector. This system contained red fluorescent protein mCherry as a marker and bile salt hydrolase gene (bsh) as a reporter gene. Moreover, in this study, four different promoters (PsppA, PldhL, P32 and PslpA) were used to regulate the expression of the fusion protein mCherry-BSH, completing the inducible and constitutive expression in lactic acid bacteria. The recombinant protein mCherry-BSH presented activity of red fluorescence and bile salt hydrolase (BSH). The successful construction of the fusion expression system in LAB using a red fluorescent protein mCherry provides favorable conditions for the distribution, intestinal colonization and survival rate of lactic acid bacteria, so as to reveal the function mechanism of its probiotic characteristics; and the system also could lay the foundation for researches on protein expression, cellular localization and properties identification of active protein in lactic acid bacteria.
Lactobacillus plantarum ; Luminescent Proteins ; Probiotics

OBJECTIVETo investigate the probiotic characteristics of Lactobacillus plantarum (L. plantarum) HO-69 in oral cavity.

METHODSThe adhesion ratios to teeth and dentine surface were determined by in vitro models. Hydrophobicity and surface charges were measured by MATH method. Inhibitory activity was measured by agar well diffusion method.

RESULTSThe adhesion ratios to hard tissue were quite low. The hydrophobicity and surface charges were high, and it exhibited inhibitory activity against some pathogens.

CONCLUSIONThe probability is low for L. plantarum HO-69 to initiate or accelerate dental caries. It shows broad-spectrum inhibitory activity and is potential probiotics applied in oral cavity.

Background: The rising public health threat brought about by antibiotic resistance, such as of Staphylococcus aureus, opened doors of opportunities for natural products research to explore novel antimicrobial agents. Objective: This study aimed to determine the antimicrobial activity of cell-free supernatants from Lactobacillus plantarum BS25 and Pediococcus acidilactici S3 against Staphylococcus aureus (ATCC# 25923) and methicillin-resistant S. aureus (ATCC# 33591). Methodology: Cell-free supernatants (CFS) of Lactobacillus plantarum BS25 and Pediococcus acidilactici S3, isolated from fermented rice-fish mixture balao-balao and fermented spicy sausage longganisa, respectively, were tested against methicillin-susceptible (MSSA, ATCC 25923) and methicillin-resistant (MRSA, ATCC 33591) Staphylococcus aureus strains for antibacterial activity using the resazurin assay. Results: Both BS25 and S3 CFS showed high activities against MSSA and partial inhibition against MRSA. Proteinaceous components of the CFS were extracted using ammonium sulfate precipitation with BS25 and S3 exhibited low activities against MSSA but partial inhibition was observed against MRSA. Other small molecules were extracted from the CFS through liquid-liquid extraction using ethyl acetate and tested in 100, 250, 500, 750, and 1000 ppm concentrations. The 1000-ppm concentrations of the BS25 and S3 ethyl acetate extracts achieved the highest antibacterial activity against MSSA and MRSA. Conclusion This study showed that the crude cell-free supernatants, ammonium sulfate precipitates, and ethyl acetate extracts of BS25 and S3 CFS exhibited potential in inhibiting Gram-positive MSSA and MRSA. However, the partially-purified samples require relatively high concentrations in order to produce significant inhibition activities and therefore require further purification.
Lactobacillus plantarum ; Pediococcus acidilactici ; Methicillin-Resistant Staphylococcus aureus

The objective of this study was to develop fermented vegetable juices that possess antidiabetic and antioxidant activities. Lactobacillus plantarum MKHA15 (MKHA15) and Leuconostoc mesenteroides MKSR (MKSR) were applied to ferment onion, cabbage, and tomato juices at 37℃ and 30℃ for 72 h, respectively, and their functionality was tested using the 12 h hour-fermented juice by MKHA15, and 48 h hour-fermented juice by MKSR. Inhibition of α-glucosidase activity was observed in all fermented juices. The onion juice fermented by MKHA15 showed significantly higher α-glucosidase inhibition activity compared to other juices. All juices showed more than 70% inhibition of α-amylase activity. The DPPH radical scavenging activity of onion juice fermented by MKSR showed significantly lower activity than cabbage and tomato juices; however, no difference was observed between the types of starter cultures. The SOD-like activity of cabbage juice fermented by MKSR was the highest among the fermented juices. The juices fermented by MKHA15 showed higher reducing power than those by MKSR. Therefore, we believe that cabbage, onion and tomato juice fermented by MKHA15 and MKSR would be useful in probiotic juices, as they possess antidiabetic and antioxidant activities.
Brassica ; Fruit and Vegetable Juices ; Lactobacillus plantarum ; Lactobacillus ; Leuconostoc ; Lycopersicon esculentum ; Onions ; Probiotics ; Vegetables

This study investigated the effects of LactoPlanta(R) (Lactobacillus plantarum (L. plantarum), 2.0 x 10(9) colony forming units (CFU)/kg) on reduction of noxious gas emission in pig houses as well as improvement of carcass weight and quality in finishing pigs. A total of 850 finishing pigs were assigned to four treatment groups: control (CON, basal diet) (n=190), LP-0.1, 0.1% LactoPlanta(R) (n=210), LP-0.2, 0.2% LactoPlanta(R) (n=230), and LP-0.4, 0.4% LactoPlanta(R) (n=220). Ammonia and hydrogen sulfide concentrations were significantly reduced in all treatment groups compared to CON. Mercaptan contents and carcass weights of LP-0.2 and LP-0.4 were significantly decreased compared to CON, whereas there were no significant differences between LP-0.1 and CON. Carcass weight of LP-0.1 was slightly higher than that of CON, but there was no significant difference. However, carcass weights of LP-0.2 and LP-0.4 were significantly higher than that of CON (P<0.05). The prevalence of grade A carcasses in groups administered with L. plantarum (46.7~63.3%) was higher than that in CON (43.3%) and increased in a dose-dependent manner. Based on the results of this study, L. plantarum could be an effective candidate to reduce noxious gas emissions in finishing pig houses as well as improve carcass weight and quality in finishing pigs.
Ammonia ; Hydrogen Sulfide ; Lactobacillus plantarum* ; Prevalence ; Stem Cells ; Swine* ; Weights and Measures

Aims: To characterize the plantaricin IIA-1A5 crude extract that biosynthesized by Lactobacillus plantarum IIA-1A5 using corn steep liquor (CSL) based medium. Methodology and results: Lactobacillus plantarum IIA-1A5 was grown in several media containing different components including corn steep liquor (CSL), molasses and MRS (de Man Rogosa Sharpe) as control medium for 24 h at 37 °C. Antibacterial activities of the cell-free supernatant were expressed as diameter of inhibition zones observed by paper disc method. The results showed that CSL medium produced cell-free supernatant of L. plantarum IIA-1A5 with significantly higher antibacterial activity againts Staphylococcus aureus ATCC 25923 (9.81 mm), Lactobacillus monocytogenes ATCC 7644 (9.61 mm), Bacillus cereus (8.97 mm) and Escherichia coli ATCC 25922 (9.23 mm) were not significantly different compared to control MRS broth media (9.59 mm). CSL medium added only with 3% yeast extract and Tween 80 produced supernatant which showed similar antibacterial activity either to 10% molasses or control medium (Medium K and B). The CSL medium was considered more efficient and low cost, therefore this medium was selected for production and characterization of plantaricin IIA-1A5 crude extract. Further characterization performed by SDS PAGE analysis showed that crude plantaricin had molecular weight of approximately 9.9 kDa, higher than that produced in control medium (8.0 kDa). However, both plantaricins were categorized under the same class for small bacteriocin (class II). This study also revealed the plantaricin IIA-1A5 produced in CSL medium was stable to heat and pH and not significantly different compared to control MRS broth media. The antibacterial activity of plantaricin IIA-1A5 crude extract against S. aureus ATCC 25923 (10.09 mm) was not significantly different with 1000 ppm sodium benzoate (9.70 mm) and 300 ppm sodium nitrite (9.82 mm). Conclusion, significance and impact of study The CSL medium produced cell-free supernatant of L. plantarum IIA 1A5 had significant antibacterial activity characterization againts S. aureus ATCC 25923, L. monocytogenes ATCC 7644, B. cereus and E. coli ATCC 25922. Comparison of the inhibition activity of plantaricin IIA-1A5 crude extract against pathogen with synthetic preservatives indicated that plantaricin IIA-1A5 crude extract have the potency to replace synthetic preservatives. CSL based medium is potential to be used for low-cost plantaricin IIA-1A5 production.
Anti-Bacterial Agents--metabolism ; Bacteriocins--metabolism ; Lactobacillus plantarum ; Microbial Viability--drug effects ; Staphylococcus aureus

γ-aminobutyric acid can be produced by a one-step enzymatic reaction catalyzed by glutamic acid decarboxylase. The reaction system is simple and environmentally friendly. However, the majority of GAD enzymes catalyze the reaction under acidic pH at a relatively narrow range. Thus, inorganic salts are usually needed to maintain the optimal catalytic environment, which adds additional components to the reaction system. In addition, the pH of solution will gradually rise along with the production of γ-aminobutyric acid, which is not conducive for GAD to function continuously. In this study, we cloned the glutamate decarboxylase LpGAD from a Lactobacillus plantarum capable of efficiently producing γ-aminobutyric acid, and rationally engineered the catalytic pH range of LpGAD based on surface charge. A triple point mutant LpGAD^{S24R/D88R/Y309K} was obtained from different combinations of 9 point mutations. The enzyme activity at pH 6.0 was 1.68 times of that of the wild type, suggesting the catalytic pH range of the mutant was widened, and the possible mechanism underpinning this increase was discussed through kinetic simulation. Furthermore, we overexpressed the Lpgad and Lpgad^{S24R/D88R/Y309K} genes in Corynebacterium glutamicum E01 and optimized the transformation conditions. An optimized whole cell transformation process was conducted under 40 ℃, cell mass (OD₆₀₀) 20, 100 g/L l-glutamic acid substrate and 100 μmol/L pyridoxal 5-phosphate. The γ-aminobutyric acid titer of the recombinant strain reached 402.8 g/L in a fed-batch reaction carried out in a 5 L fermenter without adjusting pH, which was 1.63 times higher than that of the control. This study expanded the catalytic pH range of and increased the enzyme activity of LpGAD. The improved production efficiency of γ-aminobutyric acid may facilitate its large-scale production.
Glutamate Decarboxylase/genetics* ; Lactobacillus plantarum/genetics* ; Catalysis ; gamma-Aminobutyric Acid ; Hydrogen-Ion Concentration ; Glutamic Acid

Lactic acid bacteria (LAB), including L. plantarum isolated from Kimchi, are beneficial and safe microorganisms that improve disturbances of the indigenous microflora and the host's immune system. The adhesion abilities of Kimchi-derived L. plantarum PM008 and yogurt-derived L. casei were measured in vitro and in vivo. When L. plantarum or L. casei was incubated with Caco-2 cells, these Lactobacillus strains were potently attached. When these strains were orally administered to mice, the LABs were attached on the large intestine of mice. The attachment of L. plantarum on murine intestine or Caco-2 intestinal epithelial cell lines was more potent than that of L. casei, although numbers of LAB between their feces were not different. Treatment with either L. plantarum or L. casei for 14 days suppressed fecal beta-glucuronidase activity, although treatment for one day did not affect it. L. plantarum showed more potent inhibition than L. casei. In addition, L. plantarum and L. casei were stable to artificial gastric and intestinal juice. L. plantarum was more stable than L. casei. Based on these findings, the survival and adhesion effects of orally administered LAB strains in the intestine may increase numbers of LAB in intestine and express their biological activities.
Animals ; Bacteria ; Caco-2 Cells ; Epithelial Cells ; Feces ; Glucuronidase ; Humans ; Immune System ; Intestine, Large ; Intestines ; Lactic Acid ; Lactobacillus ; Lactobacillus casei ; Lactobacillus plantarum ; Mice ; Pyridines ; Thiazoles

Probiotics that are able to provide beneficial effects on animal health have become important ingredients of dog foods. This study was conducted to characterize the probiotic potentials of two strains, Lactobacillus reuteri BCLR-42 and Lactobacillus plantarum BCLP-51, that were derived from feces of healthy dogs and evaluated based on tolerance to low pH and bile acid, antimicrobial activities, enzyme profiles, sensitivity to antibiotics, and innate immune enhancing potentials. Both strains showed survival of more than 90% at pH 3 and 0.2% bile acid and exhibited broad antimicrobial activities against indicator bacteria. Moreover, both strains showed high sensitivity to antibiotics, except vancomycin, metronidazole, and gentamicin. The alkaline phosphatase was negligible (score 0), whereas they showed strong beta galactosidase activity (score range 5 or 3, respectively). The phagocytosis and oxidative burst activities of canine granulocytes were significantly enhanced in response to both strains. These results show that both strains have the capability to act as probiotics and the potential for application as ingredients in dog foods.
Alkaline Phosphatase ; Animals ; Anti-Bacterial Agents ; Bacteria ; beta-Galactosidase ; Bile ; Dogs* ; Feces ; Gentamicins ; Granulocytes ; Hydrogen-Ion Concentration ; Lactobacillus plantarum* ; Lactobacillus reuteri* ; Lactobacillus* ; Metronidazole ; Phagocytosis ; Probiotics* ; Respiratory Burst ; Vancomycin