Correlation between changes in flavor compounds and microbial community ecological succession in the liquid fermentation of rice wine.

Microorganisms play an important role in regulating flavor compounds in rice wine, whereas we often don't understand how did they affect flavor compounds. Here, the relations between flavor compounds and microbial community ecological succession were investigated by monitoring flavor compounds and microbial community throughout the fermentation stage of rice wine. The composition of microbial community showed a dynamic change, but 13 dominant bacterial genera and 4 dominant fungal genera were detected throughout the fermentation stages. Saccharomyces presented a strong negative correlation with fungi genera but had positive associations with bacteria genera. Similarly, flavor compounds in rice wine were also showed the dynamic change, and 112 volatile compounds and 17 free amino acids were identified in the whole stages. The alcohol-ester ratio was decreased in the LTF stage, indicating that low temperature boosts ester formation. The potential correlation between flavor compounds and microbial community indicated that Delftia, Chryseobacterium, Rhizopus and Wickerhamomyces were the core functional microorganisms in rice wine. These findings clarified the correlation between changes in flavor compounds and in microbial community in the liquid fermentation of rice wine, and these results have some reference value for the quality improvement and technological optimization in liquid fermentation of rice wine.

An enzymatic colorimetric whole-cell biosensor for high-throughput identification of lysine overproducers.

L-lysine is a crucial nutrient for both humans and animals, and its main commercial use is as a supplement in animal feed to promote chicken and other animal growth. Fluorescence biosensors based on the transcriptional regulator have been developed for high-throughput screening of L-lysine producers. However, due to its inability to specifically detect lysine, this fluorescent biosensor cannot be employed to screen high-yielding strains. Here, we present a novel technique for observing L-lysine concentrations within individual Corynebacterium glutamicum cells. The transcriptional regulator LysG and its binding site, as well as the phytoene desaturase that catalyzes the synthesis of the red pigment, make up the functional core of the biosensor. The lysine-sensitive mutant LysG(E123Y, E125A), which improved the sensitivity of biosensors, was generated by site-directed saturation mutagenesis. In addition, we increased the lysine-induced chromogenic biosensor response to 320 mM by optimizing the L-lysine export mechanism and the pathway for the synthesis of lycopene precursors. The direct identification of producers with elevated L-lysine accumulation is thus made straightforward by colorimetric screening. Lys-8, a lysine producer with a maximum lysine titer of 316.2 mM, was sorted out based on the biosensor. The enzymatic colorimetric biosensor constructed here is a simple tool with great potential for the development of high-level lysine-producing C. glutamicum.

[Research progress of Rehmanniae Radix in prevention and treatment of osteoporosis].

Osteoporosis fracture with high disability and mortality is a difficult problem that seriously affects the life quality of individuals. At present, there is still a lack of anti-osteoporosis drugs with clear target and significant efficacy in the clinical practice. Rehmanniae Radix and its prescriptions have significant clinical effects. In this regard, more and more studies have reported the effects and mechanisms of Rehmanniae Radix and its active components, and the certain research outputs have been achieved. In this article, the PubMed, Web of science, China National Knowledge Infrastructure, and Wanfang database were searched to collect and organize the latest research progress of Rehmanniae Radix treatment of osteoporosis in the recent 10 years. We summarized the research dynamics as well as the function indexes and mechanisms of the raw and processed Rehmanniae Radix, active ingredients such as catalpol, aucubin, acteoside and Rehmanniae Radix polysaccharide, and their formulating prescriptions, and then excavated the potential active ingredients, targets and signaling pathways, including the effect on bone marrow mesenchymal stem cells, promoting the osteoblast proliferation and promoting osteogenesis differentiation(increasing alkaline phosphatase, typeⅠ collagen, osteoprotegerin, and osteocalcin and promoting calcium deposits), increasing the bone density, inhibiting the osteoclast quantity and differentiation, promoting the osteoclast apoptosis, and reducing tartrate resistant acid phosphatase and bone resorption pit area to provide the reference and develop new ideas for developing Rehmanniae Radix prescriptions for treatment of osteoporosis and exploring its mechanism.

Application of iron oxide nanoparticles in glioma imaging and therapy: from bench to bedside.

Gliomas are the most common primary brain tumors and have a very dismal prognosis. However, recent advancements in nanomedicine and nanotechnology provide opportunities for personalized treatment regimens to improve the poor prognosis of patients suffering from glioma. This comprehensive review starts with an outline of the current status facing glioma. It then provides an overview of the state-of-the-art applications of iron oxide nanoparticles (IONPs) to glioma diagnostics and therapeutics, including MR contrast enhancement, drug delivery, cell labeling and tracking, magnetic hyperthermia treatment and magnetic particle imaging. It also addresses current challenges associated with the biological barriers and IONP design with an emphasis on recent advances and innovative approaches for glioma targeting strategies. Opportunities for future development are highlighted.

Puerarin inhibits growth and induces apoptosis in SMMC-7721 hepatocellular carcinoma cells.

Puerarin, a predominant isoflavonoid compound extracted from the Chinese medicinal herb Radix Puerariae, is considered to exhibit an antitumor effect. In the present study, the effects of puerarin on SMMC-7721 human hepatocellular carcinoma cells were investigated. Cell viability was assessed by MTT assay. Apoptosis was detected by flow cytometry with Annexin V-fluorescein isothiocyante staining and morphological observation of nuclear changes by Hoechst staining. The mitochondrial membrane potential (MMP) was monitored using rhodamine 123. The generation of reactive oxygen species (ROS) was quantified using dichloro­dihydro­fluorescein diacetate. Polymerase chain reaction and western blot analysis were used to detect the expression levels of apoptosis­associated genes. The results revealed that high concentrations of puerarin (500, 1,000 and 1,500 µg/ml) significantly inhibited the proliferation of SMMC-7721 cells in a time- and dose-dependent manner. Simultaneously, apoptotic rates were increased and cell morphology was changed following puerarin treatment. Furthermore, puerarin­induced apoptosis of SMMC-7721 cells was associated with loss of MMP and generation of ROS. Puerarin treatment increased caspase­3,8,9 and apoptosis­inducing factor (AIF) mRNA expression levels in SMMC­7721 cells, while the phosphorylation levels of P38, extracellular signal­regulated kinase (ERK1) and c-Jun N­terminal kinase were also increased. Furthermore, caspase-9 and AIF protein expression was upregulated. In conclusion, puerarin inhibited proliferation and induced apoptosis in SMMC­7721 cells via the mitochondria­dependent pathway; however, the specific mechanisms require further investigation.

Vitamin D intake and risk of type 1 diabetes: a meta-analysis of observational studies.

Vitamin D is suggested to have protective effects against type 1 diabetes. However, the results from observational studies have been inconsistent. We aimed to examine their association by conducting a meta-analysis of observational studies. Multiple databases were searched in June 2013 to identify relevant studies including both case-control and cohort studies. Either a fixed- or random-effects model was used to calculate the pooled risk estimate. We identified eight studies (two cohort studies and six case-control studies) on vitamin D intake during early life and three studies (two cohort studies and one case-control study) on maternal vitamin D intake during pregnancy. The pooled odds ratio for type 1 diabetes comparing vitamin D supplementation with non-supplementation during early life was 0.71 (95% confidence interval [CI], 0.51-0.98). Similar results were observed in the case-control subgroup analysis but not in the cohort subgroup analysis. The pooled odds ratio with maternal intake of vitamin D during pregnancy was 0.95 (95% CI, 0.66-1.36). In conclusion, vitamin D intake during early life may be associated with a reduced risk of type 1 diabetes. However, there was not enough evidence for an association between maternal intake of vitamin D and risk of type 1 diabetes in the offspring.

[The effect of oral alpha-lipoic acid in overweight/obese individuals on brachial-ankle pulse wave velocity and supine blood pressure: a randomized, crossover, double-blind, placebo-controlled trial].

OBJECTIVE: To investigate the effect of oral alpha-lipoic acid (ALA) supplement on brachial-ankle pulse wave velocity (baPWV), supine systolic blood pressure (SBP) and diastolic blood pressure (DBP) in overweight/obese individuals. An 8-week double-blind, randomized, placebo-controlled and cross-over trial with a 4-week washout between cross-over periods. METHODS: Sixty-three males and 40 females aged 22 - 57 years old who met the inclusion criteria as (1) Han ethnicity; (2) 20 - 60 years old; (3) BMI ≥ 25 kg/m(2) and having at least one of the following risk factors: borderline hypertension (130 mm Hg ≤ SBP < 140 mm Hg and/or 85 mm Hg ≤ supine DBP< 90 mm Hg), dyslipidemia (fasting total cholesterol ≥ 5.2 mmol/L or HDL-C < 1.04 mmol/L), or impaired fasting glucose (6.1 mmol/L ≤ fasting glucose < 7.0 mmol/L); (4) Not on any antioxidant vitamin supplement. They were randomly assigned to Group 1 or Group 2 in a 1:1 ratio balanced for gender. Group 1 received 8 weeks ALA (1200 mg/day) followed by 4-week washout period and followed by another 8 weeks placebo; while Group 2 received 8 weeks placebo (1200 mg/day) followed by 4-week washout period, and followed by ALA treatment for 8 weeks. BaPWV and supine blood pressure were measured at the beginning of 1(st) phase and 2(nd) phase and at the endpoint of the whole trial. Mixed effect linear regression model was performed to compare the change of baPWV and supine blood pressure between ALA group and placebo group. RESULTS: BaPWV decreased -33.03 cm/s ± 130.70 cm/s for ALA group and increased 5.66 cm/s ± 139.89 cm/s for placebo group, supine systolic blood pressure decreased -4.09 mm Hg ± 9.18 mm Hg for ALA group and -2.32 mm Hg ± 8.16 mm Hg for placebo group. Supine diastolic blood pressure decreased -1.29 mm Hg ± 6.55 mm Hg for ALA group and -0.48 mm Hg ± 6.63 mm Hg for placebo group. These three mix-effect models did not show significant effect of ALA treatment after adjustment on baseline values, sex, age, treatment sequence or period. CONCLUSION: The current trial did not provide evidence that oral intake of ALA for 8 weeks had significant effects on lowering baPWV, supine systolic blood pressure or supine diastolic blood pressure.

Improvement of L-lactic acid production by osmotic-tolerant mutant of Lactobacillus casei at high temperature.

L-Lactic acid production by Lactobacillus casei was used as a model to study the mechanism of substrate inhibition and the strategy for enhancing L-lactic acid production. It was found that the concentration of cell growth and L-lactate decreased with the increase of glucose concentration and fermentation temperature. To enhance the osmotic stress resistance of the strain at high temperature, a mutant G-03 was screened and selected with 360 g/L glucose at 45°C as the selective criterion. To further increase the cell growth for lactic acid production, 3 g/L of biotin was supplemented to the medium. As a result, L: -lactate concentration by the mutant G-03 reached 198.2 g/L (productivity of 5.5 g L(-1) h(-1)) at 41°C in a 7-L fermentor with 210 g/L glucose as carbon source. L: -Lactate concentration and productivity of mutant G-03 were 115.2% and 97.8% higher than those of the parent strain, respectively. The strategy for enhancing L: -lactic acid production by increasing osmotic stress resistance at high temperature may provide an alternative approach to enhance organic acid production with other strains.

[Study on stability of curcumine, demethoxycurcumin and bisdemethoxycurcumin].

OBJECTIVE: To investigate the stability of curcumin, demethoxycurcumin and bisdemethoxycurcumin in different buffer solution. METHOD: To determine concentration of curcumin by HPLC when added curcumin, demethoxycurcumin and bisdemethoxycurcumin into the buffer solution the equation of degradation was established. RESULT: The sequence of stability are bisdemethoxycurcumin > or = demethoxycurcumin > or =curcumin at the same condition. CONCLUSION: The demethoxycurcumin can stabilize curcumin more strong than the others. The demethoxycurcumin is a nature stabilizing agent for curcumin.

[Study on recovery of ethyl acetate after extracting tripterygium wifordii extractum with ethyl acetate].

OBJECTIVE: To increase the recovery rate of ethyl acetate after extracting tripterygium wifordii extractum and to decrease product cost. METHOD: After extracting tripterygium wifordii extractum with ethyl acetate, 3 times saturated salt water was added in it so as to recovery ethyl acetate distilled under normal atmospheric pressure. Ethyl acetate containing salt water was purified through Na2SO4 column. RESULT: Ethyl acetate purified could be used repeatedly and the recovery rate was up to 85%. CONCLUSION: This method is completely adapted for mass production.