Characterization and identification of Lactobacillus fermentum 4,6-α-glucosyltransferase and its products / 生物工程学报

4,6-α-glucosyltransferases (4,6-α-GTs), which converts amylose into α(1-6) bonds-containing α-glucan, possesses great application potential in enzymatic synthesis of dietary fiber. Primers were designed according to the conserved motifs existing in the amino acid sequence of 4,6-α-GTs, and used to amplify a putative GTFB-Like 4,6-α-GTs gene (named as gtf16) from the genomic DNA of Lactobacillus. The gtf16 gene was cloned into the plasmid pET15b, expressed in Escherichia coli BL21(DE3), followed by purification and characterization. The optimum pH and the optimum temperature of the purified enzyme were 5.0 and 40 °C, respectively. The biotransformation product of this enzyme was systematically characterized by thin-layer chromatography, NMR spectroscopy, and hydrolysis reaction. The Gtf16-catalyzed product shows a similar structure to that of the isomalto/malto-polysaccharide (IMMP), which is the amylose-derived product catalyzed by GtfB from Lactobacillus reuteri 121. Moreover, The Gtf16-catalyzed product contains up to 75% of α(1-6) bonds and has an average molecular weight of 23 793 Da. Furthermore, the content of the anti-digestive components was 88.22% upon hydrolysis with digestive enzymes.

Streptococcus Colonial Growth of Dental Plaque Inhibition Using Flavonoid Extract of Ants Nest (Myrmecodia pendans): An in Vitro Study

Objective: To know the activity of resistance of flavonoid content in ant nest plant in decreasing the number of colonies S. mutans oral cavity of children as a medic herbal material. Material and Methods: The subjects were plaque sample of 20 children aged 7-12 years. Research begins by making toothpaste from ant nest extract. Samples of children's dental plaque were inserted into BHIB media, after which incubated for 24 hours, 1/10 dilution with BHIB media three times, followed by TYC media planting and incubation of anaerob with temperature 370C for 48 hours. After that then count the number of colonies of S. mutans. Results: On ethyl acetate extract of ant nest incubated at room temperature with concentration 20%, 40%, 60%, 80%, 100% obtained a decrease from each treatment amount of Streptococcus mutans colony on TYC media with median value of each treatment was 89, 67, 64, 61, 59 and 51 for the ethyl acetate fraction, and 62, 61, 60, 59, 49 at the ethanol fraction. There was no significant difference between the six concentration groups (p>0.05). Conclusion: Flavonoids extract of ant nest plants have growth barrier on Streptococcus mutans bacteria, the greater the concentration given the greater the number of S. mutans colony.

Effects of UDP glucuronosyltransferase 1A9 I399 C ＞ T single nucleotide polymorphism on postoperative analgesia with propofol in patients undergoing breast surgery / 中华麻醉学杂志

Objective To investigate the effects of UDP glucuronosyltransferase (UGT) 1A9 I399 C ＞ T single nucleotide polymorphism on postoperative sedation with propofol in patients undergoing breast surgery.Methods One hundred and fifty-two ASA Ⅰ or Ⅱ female patients,aged 20-50 yr,weighing 50-70 kg,scheduled for elective benign breast tumor excision under general anesthesia,were enrolled in this study.The polymorphic sites of the UGT1A9 I399 C ＞ T allele were analyzed by polymerase chain reaction-restriction fragment length polymorphism.The patients were assigned to one of 3 groups according to their genotypes:wild homozygote (C/C) group,mutation heterozygote (C/T) group and mutation homozygote (T/T) group.During induction and maintenance of anesthesia,propofol was given by target-controlled infusion with the plasma concentration (Cp) of 3μg/ml.Blood samples were taken at 60 min after target-controlled infusion of propofol was started for determination of the Cp of propofol using high-performance liquid chromatography.The time when OAAS was 4 after stopping the infusion of propofol was recorded and the BIS value and effect-site concentration of propofol were also recorded at this time.The time when BIS value was 80 was recorded and the effect-site concentration of propofol was also recorded at this time.Results Genotyping analysis revealed that genotype distribution of UGT1A9 I399 C ＞ T polymorphism was C/C 24 cases,C/T 96 cases and T/T 32 cases.The T allele frequency was 53％.The C allele frequency was 47.4％.There was no significant difference in the Cp of propofol,time when OAAS was 4,BIS value and effectsite concentration of propofol when OAAS was 4,time when BIS value was 80 and effect-site concentration of propofol when BIS value was 80 among the three groups (P ＞ 0.05).Conclusion UGT1 A9 I399C ＞ T single nucleotide polymorphism is not the genetic factor contributing to the individual variation in the patient' s response to postoperative analgesia with propofol in patients undergoing breast surgery.

Scanning Electron Microscopic study of Piper betle L. leaves extract effect against Streptococcus mutans ATCC 25175

INTRODUCTION: Previous studies have shown that Piper betle L. leaves extract inhibits the adherence of Streptococcus mutans to glass surface, suggesting its potential role in controlling dental plaque development. OBJECTIVES: In this study, the effect of the Piper betle L. extract towards S. mutans (with/without sucrose) using scanning electron microscopy (SEM) and on partially purifed cell-associated glucosyltransferase activity were determined. MATERIAL AND METHODS: S. mutans were allowed to adhere to glass beads suspended in 6 different Brain Heart Infusion broths [without sucrose; with sucrose; without sucrose containing the extract (2 mg mL-1 and 4 mg mL-1); with sucrose containing the extract (2 mg mL-1 and 4 mg mL-1)]. Positive control was 0.12 percent chlorhexidine. The glass beads were later processed for SEM viewing. Cell surface area and appearance and, cell population of S. mutans adhering to the glass beads were determined upon viewing using the SEM. The glucosyltransferase activity (with/without extract) was also determined. One- and two-way ANOVA were used accordingly. RESULTS: It was found that sucrose increased adherence and cell surface area of S. mutans (p<0.001). S. mutans adhering to 100 µm² glass surfaces (with/without sucrose) exhibited reduced cell surface area, fuffy extracellular appearance and cell population in the presence of the Piper betle L. leaves extract. It was also found that the extract inhibited glucosyltransferase activity and its inhibition at 2.5 mg mL-1 corresponded to that of 0.12 percent chlorhexidine. At 4 mg mL-1 of the extract, the glucosyltransferase activity was undetectable and despite that, bacterial cells still demonstrated adherence capacity. CONCLUSION: The SEM analysis confrmed the inhibitory effects of the Piper betle L. leaves extract towards cell adherence, cell growth and extracellular polysaccharide formation of S. mutans visually. In bacterial cell adherence, other factors besides glucosyltransferase are involved.

An experimental study of gene vaccines pcDNA3-pac and pcDNA3-gtfB of Strept ococcus mutans against dental caries in rats:the influence on weight / 实用口腔医学杂志

0.05);by the end of the experiment that was 24.5?1.05,28. 3?1.29,26.6?1.19,10.2?1.81, 26.3?1.54 and 27.3?1.38 respectively (D vs each of the other groups P0.05). Conclusion: Gene vaccines pcDNA3-pac and pcDNA3-gtfB have no unfavo rable influence on weight of gnotobiotic rats,while the inactive whole cell vac cine has.