Optimization of culture conditions for gamma-aminobutyric acid production in fermented adzuki bean milk

γ-Aminobutyric acid (GABA), a nonprotein amino acid, is widely distributed in nature and fulfills several physiological functions. In this study, various lactic acid strains commonly used to produce fermented milk products were inoculated into adzuki bean milk for producing GABA. The high GABA producing strain was selected in further experiment to improve the GABA production utilizing culture medium optimization. The results demonstrated that adzuki bean milk inoculated with Lactobacillus rhamnosus GG increased GABA content from 0.05 mg/mL to 0.44 mg/mL after 36 hours of fermentation, which showed the greatest elevation in this study. Furthermore, the optimal cultural condition to adzuki bean milk inoculated with L. rhamnosus GG to improve the GABA content was performed using response surface methodology. The results showed that GABA content was dependent on the addition of galactose, monosodium glutamate, and pyridoxine with which the increasing ratios of GABA were 23–38%, 24–68%, and 8–36%, respectively. The optimal culture condition for GABA production of adzuki bean milk was found at the content of 1.44% galactose, 2.27% monosodium glutamate, and 0.20% pyridoxine. Under the optimal cultural condition, the amount of GABA produced in the fermented adzuki bean milk was 1.12 mg/mL, which was 22.4-fold higher than that of the unfermented adzuki bean milk (0.05 mg/100 mL). The results suggested that the optimized cultural condition of adzuki bean milk inoculated with L. rhamnosus GG can increase GABA content for consumers as a daily supplement as suggested.     

Optimization of antifungal production from a novel strain Streptomyces sp. TKJ2 using response surface methodology

A newly filamentous bacteria was recovered from Tikjda forest soil (Algeria) for its high antifungal activity against various pathogenic and phytopathogenic fungi. The nucleotide sequence of the 16S rRNA gene (1454 pb) of Streptomyces sp. TKJ2 exhibited close similarity (99 %) with other Streptomyces 16S rRNA genes. Response surface methodology (RSM) was employed for optimizing this production. Three nutritional variables namely concentration of carbon source (starch), nitrogen source (casein), and NaCl were selected for the production of antifungal in submerged fermentation. Starch, casein, and NaCl were found to influence antifungal production significantly. These variables were selected for further optimization studies using a Box–Behnken design at three levels in 15 experiments using full factorial design. The statistical optimization by RSM to enhance the yield of antifungal production by Streptomyces sp. TKJ2 resulted that starch and NaCl increase, respectively, 13.05 g/l instead of 10 g/l and 2.54 g/l instead of 2 g/l. While casein decrease 0.2 g/l instead of 0.3 g/l. The present study has proved that RSM could be used as a valuable and dependable tool for the optimization of antifungal production from actinomycetes.     

响应面法优化必特螺旋霉素发酵培养基

目的利用响应面法对新一代必特螺旋霉素基因工程菌(Streptomyces spiramyceticus,WSJ-2),即含有整合型双拷贝4″位异戊酰基转移酶基因(4″-isovaleryltrasferase gene,ist)工程菌发酵培养基进行优化。方法以发酵效价和异戊酰螺旋霉素组分含量为指标,通过部分因子析因设计实验,筛选出影响较大的主要影响因子。其次,进行最陡爬坡实验,最后,通过中心组合设计,利用DX7trail 7.0软件进行回归分析,确定主要影响因子的最佳浓度,得到优化发酵培养基。结果综合培养基组成对发酵效价和组分含量的影响获得2个主要影响因子,即KH2PO4和NaCl,通过最陡爬坡实验和响应面法,确定了优化发酵培养基组成为(g.L-1):淀粉60、碳酸钙7.0、MgSO42.0、NH4NO36.0、酵母粉3.0、鱼粉15、MnCl20.10、NaCl 12.5、KH2PO40.645。验证实验表明在优化培养基中发酵相对效价为142%与预测值139%比较接近,效价比原配方提高了42%,而其总异戊酰基螺旋霉素组分的含量与原配方基本一致。结论对新构建的必特螺旋霉素基因工程菌采用响应面中心组合设计,可以较有效地进行发酵培养基的优化。     

Production and optimization of oxytetracycline by a new isolate Streptomyces rimosus using response surface methodology

A new microbial strain showing broad spectrum antibacterial and antifungal activity was isolate from soil of Chhattisgarh and characterized as Streptomyces rimosus MTCC 10792 (gene sequence similarity 99.52%). The antibacterial compound was produced by the isolate purified by silica gel chromatography and chemically characterized as oxytetracycline and production of the antibiotic was statistically optimized using response surface methodology. The three independent variables, namely concentrations of glucose (10?g/l), soybean meal (10?g/l), and calcium carbonate (1?g/l) were found to be the most important for production antibiotic by a one-factor-at-a-time study. For optimization, the individual and interaction effects of the studied variables were evaluated by response surface methodology (RSM) using central composite design (CCD). Antibiotic production was increased nearly ten times (470?mg/l) as compared with the normal unoptimized production medium (47?mg/l) by applying statistical design.     

Three-dimensional quantitative structure–activity relationship CoMFA/CoMSIA on pyrrolidine-based tartrate diamides as TACE inhibitors

A series of pyrrolidine-based tartrate diamides having selective tumor necrosis factor-α converting enzyme (TACE) inhibitory activity was selected for the three-dimensional quantitative structure–activity relationship (3D-QSAR) studies. Total 76 compounds were selected by considering a high deviation in the biological activity and structural variations. The quality and predictive power of 3D-QSAR, comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) models for the atom-based, centroid/atom-based, data-based alignments were performed. Various models were developed with the help of these alignments. The best model was developed with data-based alignment. The optimal predictive CoMFA model was obtained with cross-validated r ² = 0.53 with six component, non-cross-validated r ² = 0.94, standard error of estimates 0.23, F-value = 121.98 and optimal CoMSIA model was obtained with cross-validated r ² = 0.53 with five components, non-cross-validated r ² = 0.93, standard error of estimates = 0.24 and F-value = 138.83. These models also showed the best test set prediction with predictive r ² value of 0.65 and 0.73, respectively. Thus, on the basis of predictive power COMSIA model appeared to be the best one. The statistical parameters from these models indicate that the data are being well fitted and also have high predictive ability. Moreover, the resulting 3D-CoMFA/CoMSIA contour maps provide useful guidance for designing of highly active TACE inhibitors.     

QSAR studies on diclofenac analogues as potent cyclooxygenase inhibitors using CoMFA and CoMSIA

A series of 36 diclofenac analogues were analyzed for structure–activity relationship using CoMFA and CoMSIA. The CoMFA-based equation gave q ² = 0.625 and r ² = 0.973 compared to q ² = 0.773 and r ² = 0.959 for CoMSIA. The CoMSIA and CoMFA contours were analyzed and the structural features contributing to the enhancement of activity were identified. Based on the results obtained from these analysis two compounds were designed which show enhancement in activity compared to the parent compound. The new leads are predicted to be non-toxic through computational methods.     

A comprehensive structure–activity analysis 2,3,5-trisubstituted 4,5-dihydro-4-oxo-3H-imidazo [4,5-c] pyridine derivatives as angiotensin II receptor antagonists: using 2D- and 3D-QSAR approach

The QSAR studies were performed on a series of 2,3,5-trisubstituted 4,5-dihydro-4-oxo-3H-imidazo [4,5-c] pyridine derivatives as angiotensin II AT₁ receptor antagonists activity to find out the structural features requirements for the antihypertensive activity. The QSAR study was carried out on V-life Molecular Design Suite software and the derived best QSAR model by partial least square principal component regression and multiple linear regression method showed variation in biological activity. The statistically best significant model with high-correlation coefficient (r ² = 0.9425) was selected for further study and the resulted validation parameters of the model, cross-validated correlation coefficient (q ² = 0.7786 and pred_r ² = 0.8562) show the model has good predictive activities. The model showed that the parameters SdssCcount, SssNHcount, and SaaaCcount and H_Donor count are highly correlated with angiotensin II AT₁ receptor antagonists activity of 2,3,5-trisubstituted 4,5-dihydro-4-oxo-3H-imidazo [4,5-c] pyridine derivatives. Partial least square (PLS) methodology coupled with various feature selection methods viz. stepwise, simulated annealing and genetic algorithm were applied to derive 3D-QSAR models which were further validated for statistical significance and predictive ability by internal and external validation. Molecular field analysis was used to construct the best 3D-QSAR model-7 using k-nearest neighbor (kNN) method, showing good correlative and predictive capabilities in terms of q ² = 0.8316 and pred_r ² = 0.8152. Both 2D-and 3D-QSAR study of such derivatives provide guidance for further lead optimization and designing of potent anti-hypertensive agents.     

Screening a Strain of Aspergillus niger and Optimization of Fermentation Conditions for Degradation of Aflatoxin B1

Aflatoxin B₁, a type of highly toxic mycotoxin produced by some species belonging to the Aspergillus genus, such as Aspergillus flavus and Aspergillus parasiticus, is widely distributed in feed matrices. Here, coumarin was used as the sole carbon source to screen microorganism strains that were isolated from types of feed ingredients. Only one isolate (ND-1) was able to degrade aflatoxin B₁ after screening. ND-1 isolate, identified as a strain of Aspergillus niger using phylogenetic analysis on the basis of 18S rDNA, could remove 26.3% of aflatoxin B₁ after 48 h of fermentation in nutrient broth (NB). Optimization of fermentation conditions for aflatoxin B₁ degradation by selected Aspergillus niger was also performed. These results showed that 58.2% of aflatoxin B₁ was degraded after 24 h of culture under the optimal fermentation conditions. The aflatoxin B₁ degradation activity of Aspergillus niger supernatant was significantly stronger than cells and cell extracts. Furthermore, effects of temperature, heat treatment, pH, and metal ions on aflatoxin B₁ degradation by the supernatant were examined. Results indicated that aflatoxin B₁ degradation of Aspergillus niger is enzymatic and this process occurs in the extracellular environment.     

Experimental analysis on the main contents of Rhizoma gastrodiae extract and inter-transformation throughout the fermentation process of Grifola frondosa

Gastrodin (GA), p-hydroxylbenzaldehyde (HBA), p-hydroxybenzyl alcohol (gastrodigenin, HA) and parishin not only are the major active ingredients of Rhizoma gastrodiae, but exist transformed relations from each other throughout the fermentation process of Grifola frondosa in this work. We had found that parishin (non-free gastrodin) almost could completely transformed into gastrodin (GA, free gastrodin) after R. gastrodiae alcohol extract was sterilized by moist heat (121 °C, 30 min), but before was added into submerged cultivation of G. frondosa. However, interestingly and importantly, gastrodin re-synthesized of parishin after R. gastrodiae alcohol extract’s addition into submerged cultivation of G. frondosa. In addition, the reduction of p-hydroxylbenzaldehyde and p-hydroxybenzyl alcohol in G. frondosa fermentation process reconfirmed that the G. frondosa strain 51616 really could synthesize gastrodin into parishin by submerged fermentation. This paper firstly also reported G. frondosa’s effects on R. gastrodiae.     

Ionic liquid – microemulsions assisting in the transdermal delivery of Dencichine: Preparation,in-vitro and in-vivo evaluations,and investigation of the permeation mechanism

A novel microemulsion was developed and characterized for topical delivery of Dencichine (Den). Two imidazaolium ionic liquid, 1-hydroxyethyl-3-methylimidazolium chloride ([HOEIM]Cl) and 1-butyl-3-methylimidazolium dodecanesulfate ([BMIM]C₁₂SO₃) were incorporated into the aqueous and surfactant phases respectively for the remarkable enhancement on skin permeation. The nano-carrier was developed and optimized based on a pseudo-ternary phase diagram. The optimized formulation was composed of 50% water/[HOEIM]Cl mix (1:1) as water phase, 20% Tween 80/[BMIM]C₁₂SO₃ mix (1:1) as surfactant, 10% propylene glycol as co-surfactant and 20% IPM as oil phase. The o/w microemulsion was then characterized for droplets sizes (47.7 ± 1.5 nm), zeta potential (?14.83 ± 3.64 mV), viscosity (31 ± 4 mPa) and pH (6.71 ± 0.04). In-vitro skin permeation assay suggested the strong enhancement of ILs formulation on the topical delivery of Den, which was approximately 10-fold that of the drug aqueous solution. It was found that the nano-carrier can reduce the skin barrier properties by disrupting the regular and compact arrangements of corneocytes, and moderating the surface properties of the stratum corneum, as evidenced by Transdermal Water Loss Evaluation (TEWL), Differential Scanning Calorimetery (DSC) and attenuated total Reflectance Fourier Transform Infrared spectroscopy (ATR-FTIR). Furthermore, the in-vivo pharmacodynamic evaluation indicated the significant hemostatic activity of Den by the topical application of the vehicle. Additionally, the formulation showed minor cell toxicity and skin irritation. Therefore, our work suggested that the ionic liquid microemulsion can be a promising nano-scale vehicle for the topical application of Den to produce desirable pharmacological effects.     

Improving shared decision-making in adolescents through antibiotic education

Background Shared decision-making is vital in achieving desired drug therapy goals, especially with antibiotics, in view of the potential long-term reduction in drug resistance. However, shared decision-making is rarely practiced with adolescent patients. Objectives The aim of the study was to identify the effect antibiotic education has on willingness to engage in shared decision-making among adolescents in Malaysia. Setting Participants from secondary schools in Malaysia were enrolled with ethical approval. Method The adolescents answered a validated questionnaire, which included demographics, antibiotic knowledge, attitude towards antibiotic use, and the Control Preference Scale, which measures willingness to engage in shared decision-making. Afterwards, antibiotic education was delivered to participating students. Main outcome measure Knowledge about and attitude toward antibiotics were investigated. Results A total of 510 adolescents participated in the study. Knowledge of antibiotics significantly increased post education (pre 3.2 ± 1.8 vs. post 6.8 ± 2.1, p < 0.001), as did attitude score (pre 3.3 ± 1.7 vs. post 5.4 ± 1.9, p = 0.003). Interestingly, adolescents were less likely to be passively involved in shared decision-making post education (χ = 36.9, df = 2, p < 0.001). Adolescents who were more collaborative in shared decision-making had a significantly higher total antibiotics knowledge and attitude scores compared to those who were not collaborative (p = 0.003). Conclusion The present work demonstrates that antibiotic education improves knowledge, attitude, and willingness to engage in shared decision-making among adolescents. Antibiotic education can therefore be introduced as a strategy to reduce inappropriate antibiotic use.     

Utilization of surgical antibiotic prophylaxis for obstetrics and gynaecology surgeries in Northern Nigeria

Background Audit of antibiotic prophylaxis is an important strategy used to identify areas where stewardship interventions are required. Objectives To evaluate compliance with surgical antibiotic prophylaxis in obstetrics and gynaecology surgeries and determine the Defined Daily Dose (DDD) of antibiotic. Settings Three public tertiary hospitals located in Northern Nigeria. Methods This prospective study included women who had obstetrics and gynaecology surgeries with no infection at the time of incision. Appropriateness of antibiotic prophylaxis was determined by a clinical pharmacist. DDD of antibiotics was determined using ATC/DDD index 2017 from the World Health Organization Collaborating Centre for Drugs Statistics Methodology. Main outcome measure Compliance with antibiotic prophylaxis and DDD of antibiotic per procedure. Results A total of 248 procedures were included (mean age: 31.7?±?7.9 years). Nitroimidazole in combination with either beta-lactam/beta-lactamase inhibitor or third generation cephalosporin were the most prescribed antibiotics. Redundant anaerobic antibiotic combination was detected in 71.4% of the procedures. Timing of antibiotic prophylaxis was optimal in 16.5% while duration of prophylaxis was prolonged in all the procedures (mean duration was 8.7?±?1.0 days). The DDD of antibiotics prophylaxis was 16.75 DDD/procedure. Antibiotic utilisation was higher in caesarean section and myomectomy (17.9 DDD/procedure) than hysterectomy (14.5 DDD/procedure); P?<?0.001. Redundant metronidazole represents one-third of total DDD and 87% of the DDD for metronidazole. Conclusion Excessive and inappropriate use of antibiotic prophylaxis was observed in women who had obstetrics and gynaecology surgeries. These observations underline the need for antimicrobial stewardship interventions to improve antibiotic use.     

重组人SOD工程菌发酵表达条件的优化

采用正交试验优化重组人超氧化物歧化酶工程菌的LB培养基,得到培养基最佳配比(g/L):蛋白胨12,酵母膏5,葡萄糖1和氯化钠10.以此为基础优化基因工程菌发酵条件,确定培养基初始pH 6.5～7.5,装液量20％,菌体密度(D600) 0.55～1.4,42℃诱导表达2～3h,目的蛋白相对表达量由优化前的25％提高至4...     

Optimization of ultrasonic-assisted extraction of continentalic acid from the root of Aralia continentalis by using the response surface methodology

In order to optimize the extraction conditions of continentalic acid, the main compound from Aralia continentalis root, we developed a model using the response surface methodology. The continentalic acid yield was analyzed and quantified by high-performance liquid chromatography coupled with UV detection. The extraction solvent, temperature, and time the three main factors for ultrasound-assisted extraction were optimized using the central composite design. Analysis of variance showed a good model fit (R ² = 0.9323). The maximum extraction of continentalic acid obtained experimentally was 1.0138 % under an extraction temperature of 33 °C and extraction time of 28 min when 100 % ethanol was used as the solvent. The experimental value was in good agreement (the yield 1.0103 %) with those predicted values. The results clearly showed that quality by statistical design could be effectively applied to optimize extraction of continentalic acid.     

Pharmacodynamic model for β-lactam regimens used in surgical prophylaxis: model-based evaluation of standard dosing regimens

Background Continual evolution of resistance among bacteria against methods of surgical prophylaxis may make currently used beta-lactam regimens inadequate. Objective To re-evaluate beta-lactam regimens in surgical prophylaxis. Setting A pharmacodynamic Monte Carlo simulation (MCS) model based on a number of patients in China. Methods Pharmacodynamic profiling using Monte Carlo simulation up to 4 hours postinfusion was conducted for standard-dose, short-term (0.5 h) and prolonged (2 to 4 h) infusions of ampicillin, cefazolin, cefotaxime, cefoxitin, cefuroxime, ertapenem, and piperacillin/tazobactam in adult patients with normal renal function. Microbiological data were incorporated. Cumulative fraction of response (CFR) was determined for each regimen against populations of S. aureus, coagulase-negative staphylococci and E. coli. The optimal CFR was defined as?≥?90% response. Main Outcome Measure Cumulative fractions of response of pharmacodynamic target attainment. Results During the first 2 hours postinfusion, piperacillin/tazobactam 3.375 g exhibited consistently optimal cumulative fractions against S. aureus, CoNS and E. coli. Ampicillin 2 g (2 h) also displayed optimal CFRs for S. aureus and E. coli but not for coagulase-negative staphylococci. Cefoxitin 2 g didnot achieve any optimal CFRs, even via 2-h prolonged infusion (maximum 72.8% CFR for S. aureus and 64.5% CFR for E. coli). Cefazolin 2 g (4 h) and cefuroxime 1.5 g (4 h) provided desired CFRs across 4 h postinfusion for S. aureus but provided poor CFRs for coagulase-negative staphylococci and E. coli. Only ertapenem 1 g for E. coli and S. aureus and cefotaxime 1 g for E. coli consistently yielded?≥?90% CFRs for 4 hour postinfusion. Conclusions Certain dosing regimens may warrant adjustment for improved prevention efficiency and enhanced empirical antibiotic regimens for surgical prophylaxis.