medium optimization
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Kolonie Arcanobacterium haemolyticum na běžném krevním agaru mohou být snadno přehlédnuty.Proto byla vyvinuta diagnostická půda, na níž kolonie A. haemolyticum vytvářejí nápadnou zónuúplné hemolýzy. Jde o krevní agar připravený z Columbia Blood Agar Base (Oxoid) a 5 % pranýchovčích erytrocytů senzibilizovaných equi-faktorem (EF) Rhodococcus equi. Jako optimální se uká-zalo použití 10 jednotek aktivity (JA) EF/ml. EF byl titrován na neživném médiu skládajícím sez Agar Purified (Difco) a 5 % praných ovčích erytrocytů senzibilizovaných b-hemolyzinem (BL)Staphylococcus aureus v množství 10 JA/ml. Na stejné půdě se titroval stafylokokový b-hemolyzinna základě svého přímého hemolytického efektu. Přes velmi zřetelné hemolytické reakce kontrol-ních kmenů na diagnostické půdě s EF se během dvou let cíleného vyšetřování klinických vzorkůnepodařilo vykultivovat A. haemolyticum ani v jednom případu z 2 597 výtěrů z krku; A. haemolyti-cum však bylo na této půdě vypěstováno ve dvou případech z 223 stěrů z ran a z kožních afekcí.Navržená půda umožňuje na základě hemolytického synergismu rovněž rychlou diagnostiku druhůCorynebacterium ulcerans, Dermatophilus congolensis a Listeria monocytogenes.
Colonies of Arcanobacterium haemolyticum on common blood agar can be easily overlooked.Therefore a diagnostic medium was developed, on which A. haemolyticum colonies produce a con-spicuous zone of complete hemolysis. The medium under question is blood agar prepared from theColumbia Blood Agar Base and 5% washed sheep erythrocytes sensitised with equi factor (EF) ofRhodococcus equi. Optimally, 10 activity units (AU) of EF per 1 ml were used. EF was titrated ona non-nutrient medium consisting of agar Purified (Difco) and 5% washed sheep erythrocytessensitized with b-haemolysin (BL) of Staphylococcus aureus, 10 AU/ml. On the same medium,staphylococcal BL was titrated on the basis of its direct haemolytic effect. Despite the very distincthaemolytic reaction of the control strains evident on the diagnostic medium with EF, A. haemolyti-cum failed to grow from 2.597 throat swabs examined especially for the particular microbe duringthe a period of two years. However, A. haemolyticum was isolated on this medium twice from 223swabs from wounds and skin lesions. The proposed medium makes also the rapid diagnosis of speciesCorynebacterium ulcerans, Dermatophilus congolensis and Listeria monocytogenes on the basis ofhaemolytic synergism possible.
- MeSH
- biomedicínský výzkum MeSH
- Corynebacterium izolace a purifikace MeSH
- dítě MeSH
- dospělí MeSH
- grampozitivní nesporulující tyčinky izolace a purifikace MeSH
- hemolýza MeSH
- hemolyzinové faktory diagnostické užití izolace a purifikace MeSH
- kultivační média speciální diagnostické užití MeSH
- lidé MeSH
- Rhodococcus equi MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- lidé MeSH
Lipases are among the most significant biocatalysts that constitute the third most important group of enzymes due to their vast range of applications. The present research represents the first attempt to optimize the growth medium constituents to increase the production of recombinant lipase in Pseudomonas aeruginosa SDK-6. One factor at a time (OFAT) revealed castor oil, yeast extract, and ammonium nitrate as the most significant medium components affecting the recombinant lipase production. Further optimization via response surface methodology (RSM) resulted in lipase production of 115.50 U/mL with 0.5% (v/v) castor oil, 0.2% (w/v) yeast extract, and 0.1% (w/v) ammonium nitrate at pH 7. Statistical validation of the observed value via ANOVA revealed an F value of 117.02 at p < 0.01, with an R2 of 0.9909. An overall 3.58-fold lipase production was achieved after optimization via OFAT and RSM. The purified lipase exhibited a specific activity of 102.73 U/mg, and the molecular mass was deduced to ~ 19.5 kDa via sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The optimum temperature and pH for the recombinant lipase activity were 40 °C and 10, respectively. The enzyme retained most of its initial activity up to 32 h when incubated at an elevated temperature of 40 °C. The purified enzyme also exhibited stability over alkaline pH, with remarkable stability at pH 12. The enzyme activity was enhanced in the presence of CaCl2, MgCl2, FeCl2, NaCl, methanol, dichloromethane, and Triton X-100. The enzyme also retained most of its initial activity in the presence of all other screened organic solvents.
- MeSH
- bakteriální proteiny genetika chemie metabolismus izolace a purifikace MeSH
- koncentrace vodíkových iontů MeSH
- kultivační média * chemie metabolismus MeSH
- lipasa * genetika izolace a purifikace chemie metabolismus biosyntéza MeSH
- molekulová hmotnost MeSH
- Pseudomonas aeruginosa * genetika enzymologie metabolismus růst a vývoj MeSH
- rekombinantní proteiny genetika izolace a purifikace metabolismus chemie MeSH
- stabilita enzymů MeSH
- teplota MeSH
- Publikační typ
- časopisecké články MeSH
Response surface methodology was used to evaluate the effect of main variables such as concentration of galactose, yeast extract and wheat bran on alpha-galactosidase production from Aspergillus parasiticus MTCC-2796 under submerged fermentation conditions. A full factorial Central Composite Design was applied to study these main factors that affected alpha-galactosidase production. The experimental results showed that the optimum concentration of galactose, yeast extract and wheat bran were 1.5 %, 0.06 % and 1.5 %, respectively. This method was efficient as only 20 experiments were necessary to asses these conditions, and model adequacy was very satisfactory as the coefficient of determination was 0.9921.
The aim of the study was to identify the optimum cultivation conditions for the microalgal growth and lipid production of the oleaginous microalga Chlorella pyrenoidosa Chick (IPPAS C2). Moreover, an appropriate NO3- concentration in the cultivation medium for maximized lipid accumulation was determined. The experimental design involved a biphasic cultivation strategy with an initial biomass accumulating phase under optimized light (400 μmol/m2 per s), temperature (25 °C), and elevated CO2 concentration in the air mixture (3%), followed by a mid-elevated CO2 concentration (0.5%) for lipid induction. The highest lipid yields of 172.47 ± 18.1 and 179.65 ± 25.4 mg/L per day were detected for NO3- concentrations of 100 and 150 mg/L. The optimization approach presented here led not only to the maximization of lipid yield but also to the development of a biphasic cultivation strategy easily applicable to the cultivation process without the necessity for algal cell harvesting between the first and second cultivation phases.
- MeSH
- biomasa MeSH
- Chlorella růst a vývoj metabolismus MeSH
- dusičnany metabolismus MeSH
- fotobioreaktory MeSH
- kultivační média metabolismus MeSH
- lipidy biosyntéza MeSH
- mikrořasy růst a vývoj metabolismus MeSH
- oxid uhličitý metabolismus MeSH
- techniky vsádkové kultivace MeSH
- teplota MeSH
- Publikační typ
- časopisecké články MeSH
Protozoan hemoflagellates Leishmania are causative agents of leishmaniases and an important biological model for study of host-pathogen interaction. A wide range of methods of Leishmania cultivation on both biphasic and liquid media is available. Biphasic media are considered to be superior for initial isolation of the parasites and obtaining high promastigote infectivity; however, liquid media are more suitable for large-scale experiments. The aim of the present study was the adaptation and optimization of the cultivation of Leishmania promastigotes on a biphasic SNB-9 (saline-neopeptone-blood 9) medium that was originally developed for Trypanosoma cultivation and combines the advantages of biphasic and liquid media. SNB-9 medium is characterized with a large volume of the liquid phase, which facilitates the manipulation with the culture and provides parasite yields comparable to parasite yields on such liquid medium as Schneider's Insect Medium. We demonstrate that SNB-9 very considerably surpasses Schneider's Insect Medium in in vitro infectivity of the parasites. Additionally, we show that the ratio of apoptotic parasites, which are important for the infectivity of the inoculum, in Leishmania culture in SNB-9 is higher than in Leishmania culture in Schneider's Insect Medium. Thus, we demonstrate that the cultivation of Leishmania on SNB-9 reliably yields highly infective promastigotes suitable for experimental infection.
In January 2019, the ERA-EDTA surveyed nephrologists with questions on kidney care and kidney research designed to explore comprehension of the impact of alterations to organization of renal care and of advancements in technology and knowledge of kidney disease. Eight hundred and twenty-five ERA-EDTA members, ∼13% of the whole ERA-EDTA membership, replied to an ad hoc questionnaire. More than half of the respondents argued that kidney centres will be increasingly owned by large dialysis providers, nearly a quarter of respondents felt that many medical aspects of dialysis will be increasingly overseen by non-nephrologists and a quarter (24%) also believed that the care and long-term follow-up of kidney transplant patients will be increasingly under the responsibility of transplant physicians caring for patients with any organ transplant. Nearly half of the participants (45%, n = 367) use fully electronic clinical files integrating the clinical ward, the outpatient clinics, the haemodialysis and peritoneal dialysis units, as well as transplantation. Smartphone-based self-management programmes for the care of chronic kidney disease (CKD) patients are scarcely applied (only 11% of surveyed nephrologists), but a substantial proportion of respondents (74%) are eager to know more about the potential usefulness of these apps. Finally, European nephrologists expressed a cautious optimism about the application of omic sciences to nephrology and on wearable and implantable kidneys, but their expectations for the medium term are limited.
Various culture media have been proposed for the isolation and selective enumeration of bifidobacteria. Mupirocin is widely used as a selective factor along with glacial acetic acid. TOS (transgalactosylated oligosaccharides) medium supplemented with mupirocin is recommended by the International Dairy Federation for the detection of bifidobacteria in fermented milk products. Mupirocin media with acetic acid are also reliable for intestinal samples in which bifidobacteria predominate. However, for complex samples containing more diverse microbiota, the selectivity of mupirocin media is limited. Resistance to mupirocin has been demonstrated by many anaerobic bacteria, especially clostridia. The objective was to identify an antibiotic that inhibits the growth of clostridia and allows the growth of bifidobacteria, and to use the identified substance to develop a selective cultivation medium for bifidobacteria. The susceptibility of bifidobacteria and clostridia to 12 antibiotics was tested on agar using the disk diffusion method. Only norfloxacin inhibited the growth of clostridia and did not affect the growth of bifidobacteria. Using both pure cultures and faecal samples from infants, adults, calves, lambs, and piglets, the optimal concentration of norfloxacin in solid cultivation media was determined to be 200 mg/L. Our results showed that solid medium containing norfloxacin (200 mg/L) in combination with mupirocin (100 mg/L) and glacial acetic acid (1 mL/L) is suitable for the enumeration and isolation of bifidobacteria from faecal samples of different origins.
- MeSH
- bakteriologické techniky metody MeSH
- Bifidobacterium růst a vývoj izolace a purifikace MeSH
- dospělí MeSH
- kojenec MeSH
- kultivační média chemie MeSH
- kyselina octová metabolismus MeSH
- lidé středního věku MeSH
- lidé MeSH
- lodě MeSH
- mikrobiální testy citlivosti MeSH
- mupirocin metabolismus MeSH
- norfloxacin metabolismus MeSH
- prasata MeSH
- skot MeSH
- zvířata MeSH
- Check Tag
- dospělí MeSH
- kojenec MeSH
- lidé středního věku MeSH
- lidé MeSH
- skot MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
- práce podpořená grantem MeSH
