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1.
Background
The current study demonstrated the possibility of statistical design tools combination with computational tools for optimization of fermentation conditions for enhanced fibrinolytic protease production.Methods
The effects of using different carbon and nitrogen sources for protease production by Streptomyces radiopugnans_VITSD8 were examined by a full factorial design method. The incubation time, temperature, pH of the medium, and RPM were assessed by the predictable one factor at a time (OFAT) method. Optimization was carried out using starch and oat meal as carbon source, nitrogen source as peptic and malt extract using Fractional Factorial Design (FFD). The analysis was further continued for medium volume, temperature, initial medium pH, inoculum concentration, high determination co-efficient as (R’-0.965), and lower determination co-efficient of variation (CV-8.19%), which defines a reliable and accurate experimental value.Results
Analysis of variance by the fixed slope effect by temperature and starch; temperature and L-aspargine, temperature and oat meal, temperature and peptic extracts, temperature and pH, temperature and duration of incubation were more vital for protease production at an interactive level. Response surface plots revealed that temperature, starch, and peptic extracts affix critical concerning in temperature. Programming estimated a 28% increase in protease production. Incubation temperature and medium volume portrayed extreme impact among all factor. Starch, peptic and temperature play an important regulatory role in protease production. Optimium temperature for protease production was 33°C. The ratio of carbon and nitrogen sources and pH were the major regulatory factors in protease production by Streptomyces radiopugnans_VITSD8. It demonstrated a 4% noteworthy change in condition.Conclusion
Among all the selected parameters, temperature was the most intuitive factor, demonstrating a notable connection with the type of media and pH, while inoculum fixation had a direct impact on protein production.2.
Aim
This study aimed to develop a simplified chemically defined medium that could sustain the growth and bacteriocin (enterolysin A) production by Enterococcus faecalis B9510.Methods and Results
The nutritional requirements of E. faecalis B9510 in a chemically defined medium were determined by single omission experiments. It was observed that eight amino acids (arginine, glycine, histidine, isoleucine, leucine, methionine, tryptophan and valine), three B vitamins (nicotinic acid, Ca‐pantothenic acid and pyridoxal) and magnesium sulphate were essential for growth. Based on this information, a Simplified Defined Medium (SDM) was formed consisting of 26 components. Comparison of SDM with M‐17 showed that growth and bacteriocin production in SDM was similar to that in M‐17. The bacteriocin from SDM was then purified by ultrafiltration. The retentate of ultrafiltration step was analysed by SDS‐PAGE and the results showed a single active band in the gel, which was excised and analysed by mass spectrometry, which indicated that the active band was enterolysin A, a cell wall degrading bacteriocin.Conclusions
A simplified defined medium can be formulated for the growth and bacteriocin production by Enterococcus faecalis, whose efficiency is comparable with that of a complex commercial medium.Significance and Impact of the Study
The development of such a medium can be useful for bacteriocin production and subsequent purification in a simplified manner and, therefore, helpful in the identification of novel bacteriocins. 相似文献3.
Aims
This study aimed to examine heat curing effect (30–100°C) on antifungal activities of lime oil and its components (limonene, p‐cymene, β‐pinene and α‐pinene) at concentrations ranging from 100 to 300 μl ml?1 against Aspergillus niger in microbiological medium and to optimize heat curing of lime oil for efficient mould control on sedge (Lepironia articulata).Methods and Results
Broth dilution method was employed to determine lime oil minimum inhibitory concentration, which was at 90 μl ml?1 with heat curing at 70°C. Limonene, a main component of lime oil, was an agent responsible for temperature dependencies of lime oil activities observed. Response surface methodology was used to construct the mathematical model describing a time period of zero mould growth on sedge as functions of heat curing temperature and lime oil concentration. Heat curing of 90 μl ml?1 lime oil at 70°C extended a period of zero mould growth on sedge to 18 weeks under moist conditions.Conclusions
Heat curing at 70°C best enhanced antifungal activity of lime oil against A. niger both in medium and on sedge.Significance and Impact of the Study
Heat curing of lime oil has potential to be used to enhance the antifungal safety of sedge products. 相似文献4.
5.
Background
Xylose mother liquor has high concentrations of xylose (35%-40%) as well as other sugars such as L-arabinose (10%-15%), galactose (8%-10%), glucose (8%-10%), and other minor sugars. Due to the complexity of this mother liquor, further isolation of xylose by simple method is not possible. In China, more than 50,000 metric tons of xylose mother liquor was produced in 2009, and the management of sugars like xylose that present in the low-cost liquor is a problem. 相似文献6.
Shayne Mason Karin Terburgh Roan Louw 《Metabolomics : Official journal of the Metabolomic Society》2018,14(6):74
Introduction
The analysis of limited-quantity samples remains a challenge associated with mouse models, especially for multi-platform metabolomics studies. Although inherently insensitive, the highly specific characteristics of nuclear magnetic resonance (NMR) spectroscopy make it an advantageous platform for global metabolite profiling, particularly in mitochondrial disease research.Objectives
Show method equivalency between a well-established standard operating protocol (SOP) and our novel miniaturized 1H-NMR method.Method
The miniaturized method was performed in a 2 mm NMR tube on a standard 500 MHz NMR spectrometer with a 5 mm triple-resonance inverse TXI probe at room temperature.Results
Firstly, using synthetic urine spiked with low (50 µM), medium (250 µM) and high (500 µM) levels (n?=?10) of nine standards, both the SOP and miniaturized method were shown to have acceptable precision (CV?<?15%), relative accuracy (80–120%), and linearity (R2?>?0.95), except for taurine. Furthermore, statistical equivalence was shown using the two one-sided test. Secondly, pooled mouse quadriceps muscle extract was used to further confirm method equivalence (n?=?3), as well as explore the analytical dynamics of this novel approach by analyzing more-concentrated versions of samples (up to 10× concentration) to expand identification of metabolites qualitatively, with quantitative linearity. Lastly, we demonstrate the new technique’s application in a pilot metabolomics study using minute soleus muscle tissue from a mouse model of Leigh syndrome using Ndufs4 KO mice.Conclusion
We demonstrate method equivalency, supporting our novel miniaturized 1H-NMR method as a financially feasible alternative to cryoprobe technology—for limited-quantity biological samples in metabolomics studies that requires a volume one-tenth of the SOP.7.
Ya-Nan Gong Wei-Wei Li Jiang-Ling Sun Fei Ren Lin He Hui Jiang Qun Wang 《BMC molecular biology》2010,11(1):71
Background
Fatty acid-binding proteins (FABPs), small cytosolic proteins that function in the uptake and utilization of fatty acids, have been extensively studied in higher vertebrates while invertebrates have received little attention despite similar nutritional requirements during periods of reproductive activity. 相似文献8.
Cinzia Comino Sergio Lanteri Ezio Portis Alberto Acquadro Annalisa Romani Alain Hehn Romain Larbat Frédéric Bourgaud 《BMC plant biology》2007,7(1):14
Background
Cynara cardunculus L. is an edible plant of pharmaceutical interest, in particular with respect to the polyphenolic content of its leaves. It includes three taxa: globe artichoke, cultivated cardoon, and wild cardoon. The dominating phenolics are the di-caffeoylquinic acids (such as cynarin), which are largely restricted to Cynara species, along with their precursor, chlorogenic acid (CGA). The scope of this study is to better understand CGA synthesis in this plant. 相似文献9.
10.
Background
Elevated non-esterified fatty acids (NEFA) concentrations in non-pregnant animals have been reported to decrease pancreatic responsiveness. As ovine gestation advances, maternal insulin concentrations fall and NEFA concentrations increase. Experiments were designed to examine if the pregnancy-associated rise in NEFA concentration is associated with a reduced pancreatic sensitivity to glucose in vivo. We investigated the possible relationship of NEFA concentrations in regulating maternal insulin concentrations during ovine pregnancy at three physiological states, non-pregnant, non-lactating (NPNL), 105 and 135 days gestational age (dGA, term 147+/- 3 days). 相似文献11.
A simple, high frequency, and reproducible method for plant regeneration through direct organogenesis from cotyledonary leaf
explants of Jatropha curcas was developed using Murashige and Skoog (MS) medium supplemented with different concentrations of thidiazuron (TDZ) or 6-benzyl
aminopurine (BAP). Medium containing TDZ has greater influence on regeneration as compared to BAP. The induced shoot buds
were transferred to MS medium containing 10 μM kinetin (Kn), 4.5 μM BAP, and 5.5 μM α-naphthaleneacetic acid (NAA) for shoot
proliferation. The proliferated shoots could be elongated on MS medium supplemented with different concentrations and combinations
of BAP, indole-3-acetic acid (IAA), NAA, and indole-3-butyric acid (IBA). MS medium with 2.25 μM BAP and 8.5 μM IAA was found
to be the best combination for shoot elongation. However, significant differences in plant regeneration and shoot elongation
were observed among the genotypes studied. Rooting was achieved when the basal cut end of elongated shoots were dipped in
half strength MS liquid medium containing different concentrations and combinations of IBA, IAA, and NAA for 4 days, followed
by transfer to growth regulators free half strength MS medium supplemented 0.25 mg l−1 activated charcoal. Elongated shoot treated with 15 μM IBA, 5.7 μM IAA, and 11 μM NAA resulted in highest percent rooting.
The rooted plants could be established in soil with more than 90% survival rate. The method developed may be useful in improvement
of J. curcas through genetic modification. 相似文献
12.
Gisele André Baptista Canuto Fabiane Dörr João Henrique Ghilardi Lago André Gustavo Tempone Ernani Pinto Daniel Carvalho Pimenta João Pedro Simon Farah Maria Júlia Manso Alves Marina Franco Maggi Tavares 《Metabolomics : Official journal of the Metabolomic Society》2017,13(5):56
Introduction
Leishmaniasis is a parasitic neglected disease affecting millions of people worldwide. Clinical practice resorts to long and costly treatments with a therapeutic arsenal limited to highly toxic drugs, often associated to adverse side effects. Additionally, resistant strains are reported to be increasing.Aim
In this work, the mechanistic action of a drug candidate (methydehydrodieugenol B), isolated from twigs of Nectandra leucantha, towards Leishmania infantum was studied by a global metabolomics approach using GC-MS and RPLC-MS platforms.Method
L. infantum promastigotes were grown in culture medium for 72 h and treated with methydehydrodieugenol B at 58.18 μg.mL-1 concentration; after 48 h treatment, enzyme activity was quenched, cells washed and frozen until analysis. For GC-MS analysis (Fiehn’s method), 1:1 methanol:water extracts were prepared and derivatized with O-methoxyamine in pyridine at room temperature for 90 min, followed by silylation with BSTFA/1% TMCS at 40 °C for 30 min. Pure methanolic extracts were also prepared and analyzed directly by RPLC-MS with a acetonitrile/water mobile phase acidulated with formic acid and gradient elution.Result
Several amino acids, fatty acids, carbohydrates, and glycerolipids were found as discriminant metabolites, mostly decreased in treated samples. Due to the complexity of the parasite metabolism and the great diversity of altered metabolites, a multi-target mechanism was assigned to the drug candidate, where changes in the cell energy sources and in the lipid composition of the parasite plasma membrane were prominent.Conclusion
These results contributed to elucidate the broad action of methyldehydrodieugenol B against Leishmania, paving the way in the search of novel alternative therapies.13.
A. Cadiere B. Couturaud J. Boismard P. Le Cann A. Gérard A. Mas C. Faye L. Garrelly B. Roig 《Journal of applied microbiology》2013,115(1):290-297
Aims
Virus detection has often been difficult due to a low concentration in water. In this study, we developed a new procedure based on concentration of virus particles on an innovative support: poly‐l ‐lysine dendrigrafts (DGL), coupled with directed nucleic acid extraction and real‐time PCR quantification.Methods and Results
This method was evaluated using the bacteriophage MS2 as a model virus. This virus exhibited the size and structural properties of human pathogenic enteric viruses and has often been used to assess new supports of concentration. Moreover, this bacteriophage is also a faecal contamination indicator. In this study, many water filtration conditions were tested (volume of water, concentration, etc.), and more than 80% of bacteriophage were recovered after filtration on polymer, in most conditions. We demonstrated that the method was linear (slope = 0·99 ± 0·04 and Y intercept when x = ?0·02 ± 0·28), valid (as manipulators, tested concentrations, volumes of sample and batch of polymer did not have any influence on concentration) and sensitive (allowing to concentrate up to 16 600‐fold 1 l of sample and to detect and quantify down to 750 GC l?1 and 7500 GC l?1, respectively).Conclusions
To conclude, this support exhibits high interest to retain viruses and to allow to detect low concentration of virus in water.Significance and Impact of the Study
This study gives valuable advance in the methods of concentration and diagnosis of virus in water. 相似文献14.
Aims
To evaluate the interaction between selected yeasts and bacteria and associate their metabolic activity with secondary cucumber fermentation.Methods and Results
Selected yeast and bacteria, isolated from cucumber secondary fermentations, were inoculated as single and mixed cultures in a cucumber juice model system. Our results confirmed that during storage of fermented cucumbers and in the presence of oxygen, spoilage yeasts are able to grow and utilize the lactic and acetic acids present in the medium, which results in increased brine pH and the chemical reduction in the environment. These conditions favour opportunistic bacteria that continue the degradation of lactic acid. Lactobacillus buchneri, Clostridium bifermentans and Enterobacter cloacae were able to produce acetic, butyric and propionic acids, respectively, when inoculated in the experimental medium at pH 4·6. Yeast and bacteria interactions favoured the survival of Cl. bifermentans and E. cloacae at the acidic pH typical of fermented cucumbers (3·2), but only E. cloacae was able to produce a secondary product.Conclusions
The methodology used in this study confirmed that a complex microbiota is responsible for the changes observed during fermented cucumber secondary fermentation and that certain microbial interactions may be essential for the production of propionic and butyric acids.Significance and Impact of the Study
Understanding the dynamics of the development of secondary cucumber fermentation aids in the identification of strategies to prevent its occurrence and economic losses for the pickling industry. 相似文献15.
Tooth loss and its relationship with protein intake by elderly Brazilians—A structural equation modelling approach 下载免费PDF全文
Objective
This study aimed at assessing the relationship between self‐perceived tooth loss and wearing dentures, on the one hand, and the consumption of protein, on the other hand, among the elderly population of Botucatu, SP. Food consumption tends to decrease with ageing, especially protein intake, and one of the causes could be the precariousness of oral health. Several risk factors associated with deficient dietary protein intake have been identified, namely greater physical dependence, reduced caloric intake and food insecurity, but no studies have analysed whether tooth loss and prostheses interfere with protein intake.Methods
An interview was conducted among 365 elderly individuals, in which we examined oral health‐related quality of life (OHRQoL) as the only latent variable, in a 24‐hour nutritional assessment dietary recall repeated 3 times, conducted in person by a trained nutritionist and also performed an analysis of nutritional needs using the Nutrition Data System Research (NDSR) Program.Results
The structural equation model, performed using Stata v.14, showed that lack of teeth (standardised coefficient [SC] = 0.21, P < .001), and prosthesis use (SC = ?0.21, P < .001) was associated with OHRQoL. Lack of teeth had a direct effect on the consumption of animal protein (SC = 0.08, P = .02), a strong total effect on animal protein intake (SC = 0.51, P = .04) and a medium effect on total protein intake (SC = 0.20, P = .03), adjusted for confounders (depression and medical problems).Conclusion
Tooth loss had a strong and significant total effect on animal protein intake and a medium effect on total protein intake among elderly Brazilians. 相似文献16.
Background
Polyamines such as spermine and spermidine are required for growth ofEscherichia coli; they interact with nucleic acids, and they bind to ribosomes. Polyamines block porins and decrease membrane permeability, activities that may protect cells in acid. At high concentrations, however, polyamines impair growth. They impair growth more severely at high pH, probably due to their increased uptake as membrane-permeant weak bases. The role of pH is critical in understanding polyamine stress. 相似文献17.
Renato S. Gonçalves Patrícia V. Abdelnur Vanessa G. Santos Rosineide C. Simas Marcos N. Eberlin Alviclér Magalhães Eduardo R. Pérez González 《Amino acids》2011,40(1):197-204
Abstract
Potentially bioactive N-(aminoalkyl)lactamic amino acids and esters were synthesized in satisfactory to good yields by SNAr reactions of aromatic acids with N-(3-aminopropyl)lactams followed by esterification with tertiary amino alcohols. The addition–elimination SNAr mechanism was confirmed by NMR and MS measurements. 相似文献18.
Telomere length determined by the fluorescence in situ hybridisation distinguishes malignant and benign cells in cytological specimens 下载免费PDF全文
Y. Matsuda A. Suzuki S. Esaka Y. Hamashima M. Imaizumi M. Kinoshita H. Shirahata Y. Kiso H. Kojima M. Matsukawa Y. Fujii N. Ishikawa J. Aida K. Takubo T. Ishiwata M. Nishimura T. Arai 《Cytopathology》2018,29(3):262-266
Background
Telomeres are tandem repeats of TTAGGG at the end of eukaryotic chromosomes that play a key role in preventing chromosomal instability. The aim of the present study is to determine telomere length using fluorescence in situ hybridisation (FISH) on cytological specimens.Methods
Aspiration samples (n = 41) were smeared on glass slides and used for FISH.Results
Telomere signal intensity was significantly lower in positive cases (cases with malignancy, n = 25) as compared to negative cases (cases without malignancy, n = 16), and the same was observed for centromere intensity. The difference in DAPI intensity was not statistically significant. The ratio of telomere to centromere intensity did not show a significant difference between positive and negative cases. There was no statistical difference in the signal intensities of aspiration samples from ascites or pleural effusion (n = 23) and endoscopic ultrasound‐guided FNA samples from the pancreas (n = 18).Conclusions
The present study revealed that telomere length can be used as an indicator to distinguish malignant and benign cells in cytological specimens. This novel approach may help improve diagnosis for cancer patients. 相似文献19.
Background
Exopolysaccharides (EPSs) produced by lactic acid bacteria are important for the texture of fermented foods and have received a great deal of interest recently. However, the low production levels of EPSs in combination with the complex media used for growth of the bacteria have caused problems in the accurate analysis of the EPS. The purpose of this study was to find a growth medium for physiological studies of the lactic acid bacterium Streptococcus thermophilus, and to develop a simple method for qualitative and quantitative analysis of EPSs produced in this medium. 相似文献20.
Jessica C Zweers Imrich Barák Dörte Becher Arnold JM Driessen Michael Hecker Vesa P Kontinen Manfred J Saller L'udmila Vavrová Jan Maarten van Dijl 《Microbial cell factories》2008,7(1):10