To improve the productivity of L-phenyllactic acid (L-PLA), L-LcLDH1(Q88A/I229A), a Lactobacillus casei L-lactate dehydrogenase mutant, was successfully expressed in Pichia pastoris GS115. An NADH regeneration system in vitro was then constructed by coupling the recombinant (re) LcLDH1(Q88A/I229A) with a glucose 1-dehydrogenase for the asymmetric reduction of phenylpyruvate (PPA) to L-PLA. SDS-PAGE analysis showed that the apparent molecular weight of reLcLDH1(Q88A/I229A) was 36.8 kDa. And its specific activity was 270.5 U/mg, 42.9-fold higher than that of LcLDH1 (6.3 U/mg). The asymmetric reduction of PPA (100 mmol/L) was performed at 40 °C and pH 5.0 in an optimal biocatalytic system, containing 10 U/mL reLcLDH1(Q88A/I229A), 1 U/mL SyGDH, 2 mmol/L NAD⁺ and 120 mmol/L D-glucose, producing L-PLA with 99.8% yield and over 99% enantiomeric excess (ee). In addition, the space-time yield (STY) and average turnover frequency (aTOF) were as high as 9.5 g/(L·h) and 257.0 g/(g·h), respectively. The high productivity of reLcLDH1(Q88A/I229A) in the asymmetric reduction of PPA makes it a promising biocatalyst in the preparation of L-PLA.
L-Lactate Dehydrogenase ; genetics ; Lactobacillus casei ; enzymology ; genetics ; Phenylpyruvic Acids ; metabolism ; Pichia ; genetics ; Recombinant Proteins ; genetics ; metabolism

To evaluate immune efficacy of the recombinant Lactobacillus casei, we constructed pLA-Newcastle disease virus (NDV)-F/L. casei and obtained the expression products. PCR amplified the NDV F gene carrying part of the major epitopes. The target gene was inserted to the shuttle plasmid pLA, and then transformed into Escherichia coli BL21 (DE3) in order to screen positive recombinant plasmid. The positive recombinant plasmid was transformed into L. casei by electroporation to construct pLA-NDV-F/L. casei. The positive strains were identified by PCR. The reactivity of the recombinant bacteria was identified by Western blotting and the protein expression was detected by indirect immunofluorescence, flow cytometry and laser confocal microscopy. The 14-day-old chickens in each group were vaccinated by oral plus nose drops. The pLA-NDV-F/L. casei twice immunization group and three times immunization group, the commercial vaccine group, the pLA/L. casei group, the unchallenge PBS and the challenge PBS group were established. IgG in serum and sIgA in the lavage fluid of intestinal, nasal and lung were detected by ELISA. The protection rate of chickens was evaluated. The results showed that 94.10% of the recombinant bacteria expressed the F protein. The recombinant protein was highly expressed on the surface of L. casei with a protein size of 62 kDa, which specifically bound to anti-NDV serum. The levels of anti-F IgG and sIgA antibodies in each test group were significantly higher than those in the control groups. The duration of antibody in the pLA-NDV-F/L. casei three-time immunization group lasted 28 days longer than that in the twice immunized group, and there was no significant difference between antibody peak values. The attack protection rates in each group of immunized pLA-NDV-F/L. casei three times, twice, attenuated vaccine, pLA/L. casei and PBS were 80%, 80%, 90%, 0% and 0%, respectively. Therefore, the antigenic protein of NDV F was successfully expressed by L. casei expression system, which has of reactogenicity and immunogenicity, and could induce protective immune responses in chickens.
Animals ; Antibodies, Viral ; Chickens ; Immunization ; Lactobacillus casei ; Newcastle disease virus ; Vaccines, Attenuated ; Viral Vaccines

BACKGROUND/AIMS: Probiotics are expected to confer benefits on patients with constipation, but how probiotics act on constipated patients with variable stool consistencies remains unclear. We investigated the effect of Lactobacillus casei strain Shirota (LcS) on constipation-related symptoms, especially stool consistency, of constipated patients. METHODS: Constipated patients meeting the Rome III criteria were divided into 3 groups according to the Bristol Stool Form Scale (BSFS): hard (hard stool [HS], BSFS < 3), normal (normal stool [NS], ≤ 3 BSFS ≤ 4), and soft (soft stool [SS], 4 < BSFS ≤ 5) stools. Subjects in each group consumed a probiotic beverage containing 1010 colony-forming units of LcS daily for 28 days. RESULTS: LcS intervention significantly alleviated constipation-related symptoms and increased defecation frequency in all subjects. Four weeks of LcS supplementation softened the hard stools in HS, hardened the soft stools in SS, and did not alter the ideal stool consistency in NS. The short-chain fatty acid (SCFA) concentrations were highest in SS, followed by NS and HS. LcS intervention increased the stool SCFA levels in HS but reduced or did not alter the levels in NS and SS. LcS intervention increased the Pseudobutyrivibrio and Roseburia abundances in HS and decreased the Pseudobutyrivibrio abundance in SS. CONCLUSIONS: LcS supplementation improved the constipation-related symptoms in constipated subjects. Differences in baseline stool consistency could result in different anti-constipation effects of LcS intervention. LcS balanced the stool consistency—softened the HS and hardened the SS. These effects could be associated with modulation of the gut microbiota and SCFA production.
Beverages ; China ; Constipation ; Defecation ; Fatty Acids, Volatile ; Gastrointestinal Microbiome ; Humans ; Lactobacillus casei ; Lactobacillus ; Probiotics ; Stem Cells

BACKGROUND: Factors affecting oral function include tooth number, oral muscle strength, and oral diseases. This study aimed to investigate the relationship among oral environment, muscle, and microbiology. METHODS: Fifty-six elderly individuals in a day care center were included in the study. The survey regarding tongue and lip muscle strength and oral microorganisms was conducted from November to December 2018. RESULTS: Tongue and lip muscle strength were greater in men than women (p>0.05). Tongue muscle strength was greater in the ≤80-year-old group (34.94±9.85) than the ≥90-year-old group (25.57±7.54) (p<0.05). Tongue muscle strength and lip muscle strength were greater in the ≥15 functional teeth group (34.08±9.31 and 9.25±1.63, respectively) than in the <15 functional teeth group (28.08±7.53 and 7.76±1.51, respectively) (p<0.05). Age was significantly correlated with functional tooth number, denture use, and tongue muscle strength. The number of functional teeth was positively correlated with tongue muscle strength, lip muscle strength, and oral microorganisms. Denture use was negatively correlated with tongue and lip muscle strength. Tongue muscle strength was significantly correlated with lip muscle strength. The number of Eubacterium nodatum was higher in men than women. The number of Parvimonas micra and Enterococcus faecalis was higher in the groups with ≥15 functional teeth, denture use, and greater tongue and lip muscle strength. The number of Lactobacillus casei was higher in the group that uses dentures and with greater tongue strength. CONCLUSION: Oral microbiology is more important in oral environment and management than oral muscle function. The correlation between oral muscle and oral microorganism requires further study. Therefore, oral care training should be conducted to improve the oral care practice of elderly individuals, maintain oral health through oral care, and prevent the decrease in saliva secretion by aging.
Aged ; Aging ; Day Care, Medical ; Dentures ; Enterococcus faecalis ; Eubacterium ; Female ; Humans ; Lactobacillus casei ; Lip ; Male ; Muscle Strength ; Oral Health ; Oral Hygiene ; Saliva ; Tongue ; Tooth

OBJECTIVE: Persistent infection of HPV increases the chance of carcinoma in situ of cervix through stages of cervical intraepithelial neoplasia (CIN) 1, 2, and 3, and finally progresses into cervical cancer. We aimed to explore the safety and efficacy of BLS-M07 which is orally administered agent expressing human papillomavirus (HPV) 16 E7 antigen on the surface of Lactobacillus casei in patients with CIN 3. METHODS: Patients with CIN 3 were recruited in our clinical trial. Reid Colposcopic Index (RCI) grading and serum HPV16 E7 specific antibody production were used to evaluate efficacy of BLS-M07. In phase 1, BLS-M07 was administered orally, 5 times a week, on weeks 1, 2, 4, and 8 with dosages of 500 mg, 1,000 mg, and 1,500 mg. In phase 2a, patients were treated with 1,000 mg. The primary endpoints were the safety and the pathologic regression on colposcopic biopsy. RESULTS: Nineteen patients were enrolled in the CIN 3 cohort. In phase 1, no patients experienced dose limiting toxicity. No grade 3 or 4 treatment-related adverse events or deaths were observed. At 16 weeks after treatment, RCI grading was improved and serum HPV16 E7 specific antibody production increased (p<0.05). Six of 8 (75%) patients with CIN 3 were cured in phase 2a. CONCLUSIONS: Oral immunization with BLS-M07 increases production of serum HPV16 E7 specific antibody which induces protective humoral immunity. The safety of this oral vaccine was proved and could be a competitive non-surgical therapeutic agent of CIN 3. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02195089
Antibody Formation ; Biopsy ; Carcinoma in Situ ; Cervical Intraepithelial Neoplasia ; Cervix Uteri ; Cohort Studies ; Female ; Humans ; Immunity, Humoral ; Immunization ; Lactobacillus casei ; Papillomavirus E7 Proteins ; Papillomavirus Vaccines ; Uterine Cervical Neoplasms

OBJECTIVES: Dental plaque emits red fluorescence under a visible blue light near the ultra-violet end of the light spectrum. The fluorescence characteristics of each microorganism have been reported in several studies. The aim of this study was to evaluate changes in red fluorescence of oral microorganisms that is affected by blood in the culture media. METHODS: The gram-positive Actinomyces naeslundii (AN, KCTC 5525) and Lactobacillus casei (LC, KCTC 3109) and gram negative Prevotella intermedia (PI, KCTC 3692) that are known to emit red fluorescence were used in this study. Each bacterium was activated in broth and cultivated in different agar media at 37℃ for 7 days. Tryptic soy agar with hemin and vitamin K3 (TSA), TSA with sheep blood (TSAB), basal medium mucin (BMM) medium, and BMM with sheep blood (BMMB) were used in this study. Fluorescence due to bacterial growth was observed under 405-nm wavelength blue light using the quantitative light-induced fluorescence-digital (QLF-D) device. The red, green, and blue fluorescence values of colonies were obtained using image-analysis software and the red to green ratio (R/G value) and red to total RGB ratio (R/RGB value) were calculated for quantitative comparison. RESULTS: The QLF-D images of the AN, LC, and PI colonies showed red fluorescence in all media, but the fluorescence of all bacteria was reduced in TSA and BMM media, compared with in TSAB and BMMB media. Both the R/G and the R/RGB values of all bacteria were significantly reduced in growth media without blood (P<0.001). CONCLUSIONS: Based on this in vitro study, it can be concluded that red fluorescence of oral bacteria can be affected by growth components, especially blood. Blood-containing medium could be a significant factor influencing red fluorescence of oral bacteria. It can be further hypothesized that bleeding in the oral cavity can increase the red fluorescence of dental plaque.
Actinomyces ; Agar ; Bacteria* ; Culture Media ; Dental Plaque ; Fluorescence* ; Hemin ; Hemorrhage ; In Vitro Techniques ; Lactobacillus casei ; Mouth ; Mucins ; Prevotella intermedia ; Sheep ; Vitamin K 3

OBJECTIVES: Dental plaque is composed of 700 bacterial species. It is known that some oral microorganisms produce porphyrin, and thus, they emit red fluorescence when illuminated with blue light at a specific wavelength of <410 nm. Porphyromonas gingivalis belongs to the genus Porphyromonas, which is characterized by the production of porphyrin. The aim of this study was to evaluate red fluorescence emission of some oral microorganisms interacting with P. gingivalis. METHODS: Five bacterial strains (P. gingivalis, Streptococcus mutans, Lactobacillus casei, Actinomyces naeslundii, and Fusobacterium nucleatum) were used for this study. Tryptic soy agar medium supplemented with hemin, vitamin K3, and sheep blood was used as a growth medium. The fluorescence emission of bacterial colonies was evaluated under 405 nm-wavelength blue light using a Quantitative Light-induced Fluorescence Digital (QLF-D) camera system. Each bacterium was cultured alone and co-cultured in close proximity with P. gingivalis. The red/green (R/G) ratio of fluorescence image was calculated and the differences of R/G ratio according to each growth condition were compared using the Mann-Whitney test (P<0.05). RESULTS: Single cultured S. mutans, L. casei and A. naeslundii colonies emitted red fluorescence (R/G ratio=2.15±0.06, 4.31±0.17, 5.52±1.29, respectively). Fusobacterium nucleatum colonies emitted green fluorescence (R/G ratio=1.36±0.06). The R/G ratios of A. naeslundii and F. nucleatum were increased when P. gingivalis was co-cultured with each bacterium (P<0.05). In contrast, the R/G ratios of S. mutans and L. casei were decreased when P. gingivalis was co-cultured with each bacterium (P=0.002, 0.003). CONCLUSIONS: This study confirmed that P. gingivalis could affect the red fluorescence of other oral bacteria under 405 nm-wavelength blue light. Our findings concluded that P. gingivalis has an important role for red fluorescence emission of dental biofilm.
Actinomyces ; Agar ; Bacteria* ; Biofilms ; Dental Plaque ; Fluorescence* ; Fusobacterium ; Fusobacterium nucleatum ; Hemin ; Lactobacillus casei ; Porphyromonas gingivalis* ; Porphyromonas* ; Sheep ; Streptococcus mutans ; Vitamin K 3

OBJECTIVES: The purpose of this study was to evaluate the growth inhibitory effects of some vegetable oils on Streptococcus mutans (S. mutans) and Lactobacillus casei (L. casei). METHODS: Two bacterial strains and 5 kinds of test solutions (3 experimental groups: orange essential oil, olive oil, soybean oil; 1 positive control group: chlorhexidine solution; 1 negative control group: broth medium) were used in this study. S. mutans and L. casei pellets were exposed to 1 ml of one of the test solutions for 1 minute. Then, the treated bacterial cells were incubated in fresh broth medium for 0, 4, 8, 16, and 24 hours. The optical density of the broth medium was measured using an ELISA reader at 620 nm. A nonparametric Kruskal-Wallis test (with Mann-Whitney U tests) was performed to compare the change in optical density between different groups at different time points. RESULTS: Bacterial growth was significantly inhibited in all experimental groups compared to the negative control group. The growth of L. casei was less affected by experimental oils than that of S. mutans. Orange essential oil had the maximum growth inhibitory effect on S. mutans up to 8 hours, similar to that in the positive control group (P<0.01). Experimental oils had greater growth inhibitory effect on L. casei than chlorhexidine solution. CONCLUSIONS: This in vitro study confirmed the growth inhibitory effect of some vegetable oils on S. mutans and L. casei. Rising of the mouth using these vegetable oils is expected to have an anti-plaque effect, but additional clinical studies are needed to confirm this.
Chlorhexidine ; Citrus sinensis ; Enzyme-Linked Immunosorbent Assay ; Lactobacillus casei* ; Lactobacillus* ; Mouth ; Oils ; Olea ; Plant Oils* ; Soybean Oil ; Streptococcus mutans* ; Streptococcus* ; Vegetables* ; Olive Oil

Hypertension can be caused by various factors while the predominant causes include increase in body fluid volume and resistance in the circulatory system that elevate the blood pressure. Consumption of probiotics has been proven to attenuate hypertension; however, the effect is much strain-dependent. In this study, a newly isolated Lactobacillus casei (Lb. casei) strain C1 was investigated for its antihypertensive properties in spontaneously hypertensive rats (SHR). Lactic acid bacteria (LAB) suspension of 11 log colony-forming unit (CFU) was given to SHR (SHR+LAB, n=8), and phosphate buffer saline (PBS) was given as a control in SHR (SHR, n=8) and in Wistar rats as sham (WIS, n=8). The treatment was given via oral gavage for 8 weeks. The results showed that the weekly systolic blood pressure (SBP), mean arterial pressure (MAP), diastolic blood pressure (DBP) and aortic reactivity function were remarkably improved after 8 weeks of bacterial administration in SHR+LAB. These effects were mostly attributed by restoration of wall tension and tensile stress following the bacterial treatment. Although not statistically significant, the level of malondialdehye (MDA) in SHR+LAB serum was found declining. Increased levels of glutathione (GSH) and nitric oxide (NO) in SHR+LAB serum suggested that the bacterium exerted vascular protection through antioxidative functions and relatively high NO level that induced vasodilation. Collectively, Lb. casei strain C1 is a promising alternative for hypertension improvement.
Arterial Pressure ; Bacteria ; Blood Pressure ; Body Fluids ; Glutathione ; Hypertension ; Lactic Acid ; Lactobacillus casei* ; Lactobacillus* ; Nitric Oxide ; Probiotics ; Rats, Inbred SHR* ; Rats, Wistar ; Stem Cells ; Vasodilation

Halitosis is caused by consumption of certain foods or drinks and production of volatile sulfur compounds (VSCs) by periodontopathogens. VSCs-related halitosis is not easily removed using mechanical or chemical therapies such as dental floss, plaque control and mouth rinse. Lactobacillus are known to be probiotics and stimulate immune systems of human. Furthermore, L. casei ATCC 334 and L. rhamnosus GG have an effect on protection of dental caries in vitro studies. The aim of this study was to investigate effect of Lactobacillus on halitosis by Fusobacterium nucleatum- and Porphyromonas gingivalis- producing VSCs and to analyze inhibitory mechanism. The periodontopathogens were cultivated in the presence or the absence Lactobacillus, and the level of VSCs was measured by gas chromatograph. For analysis of inhibitory mechanisms, the susceptibility assay of the spent culture medium of Lactobacillus against F. nucleatum and P. gingivalis was investigated. Also, the spent culture medium of Lactobacillus and periodontopathogens were mixed, and the emission of VSCs from the spent culture medium was measured by gas chromatograph. L. casei and L. rhamnosus significantly reduced production of VSCs. L. casei and L. rhamnosus exhibited strong antibacterial activity against F. nucleatum and P. gingivalis. The spent culture medium of L. casei inhibited to emit gaseous hydrogen sulfide, methyl mercaptan and dimethyl sulfide from the spent culture medium of periodontopathogens. However, the spent medium of L. rhamnosus repressed only dimethyl sulfide. L. casei ATCC 334 may improve halitosis by growth inhibition of periodontopathogens and reduction of VSCs emission.
Dental Caries ; Dental Devices, Home Care ; Fusobacterium ; Halitosis* ; Humans ; Hydrogen Sulfide ; Immune System ; Lactobacillus ; Lactobacillus casei* ; Mouth ; Porphyromonas ; Probiotics ; Sulfur Compounds