The main entrance point of highly toxic organic Hg forms, including methylmercury (MeHg), into the aquatic food web is phytoplankton, which is greatly represented by various natural microalgal species. Processes associated with MeHg fate in microalgae cells such as uptake, effects on cells and toxicity, Hg biotransformation, and intracellular stability are detrimental to the process of further biomagnification and, as a consequence, have great importance for human health. The study of MeHg uptake and distribution in cultures of marine halophile Dunaliella salina and freshwater acidophilic alga Coccomyxa onubensis demonstrated that most of the MeHg is imported inside the cell, while cell surface adhesion is insignificant. Almost all MeHg is removed from the culture medium after 72 h. Significant processes in rapid MeHg removal from liquid medium are its abiotic photodegradation and volatilization associated with algal enzymatic activity. The maximum intracellular accumulation for both species was in 80 nM MeHg-exposed cultures after 24 h of exposure for D. salina (from 27 to 34 µg/gDW) and at 48 h for C. onubensis (up to 138 µg/gDW). The different Hg intakes in these two strains could be explained by the lack of a rigid cell wall in D. salina and the higher chemical ability of MeHg to pass through complex cell wall structures in C. onubensis. Electron microscopy studies on the ultrastructure of both strains demonstrated obvious microvacuolization in the form of many very small vacuoles and partial cell membrane disruption in 80 nM MeHg-exposed cultures. Results further showed that Coccomyxa onubensis is a good candidate for MeHg-contaminated water reclamation due to its great robustness at nanomolar concentrations of MeHg coupled with its very high intake and almost complete Hg removal from liquid medium at the MeHg levels tested.
- Klíčová slova
- mercury contamination, mercury toxicity, methylmercury, microalgae,
- Publikační typ
- časopisecké články MeSH
Microalgae are mostly phototrophic microorganisms present worldwide, showcasing great adaptability to their environment. They are known for producing essential metabolites such as carotenoids, chlorophylls, sterols, lipids, and many more. This study discusses the possibility of the mixotrophic abilities of microalgae in the presence of food waste oils. The utilization of food waste materials is becoming more popular as a research subject as its production grows every year, increasing the environmental burden. In this work, waste frying oil and coffee oil were tested for the first time as a nutrition source for microalgae cultivation. Waste frying oil is produced in large amounts all over the world and its simple purification is one of its greatest advantages as it only needs to be filtered from leftover food pieces. Coffee oil is extracted from waste spent coffee grounds as a by-product. The waste frying oil and coffee oil were added to the basic algal media as an alternative source of carbon. As a pilot study for further experimentation, the effect of oil in the medium, algal adaptability, and capability to survive were tested within these experiments. The growth and production characteristics of four algae and cyanobacteria strains were tested, of which the strain Desmodesmus armatus achieved exceptional results of chlorophyll (8.171 ± 0.475 mg/g) and ubiquinone (5.708 ± 0.138 mg/g) production. The strain Chlamydomonas reindhartii showed exceptional lipid accumulation in the range of 30-46% in most of the samples.
- Klíčová slova
- coffee oil, cyanobacteria, lipids, metabolites, microalgae, waste frying oil,
- Publikační typ
- časopisecké články MeSH
The consequence of the massive increase in population in recent years is the enormous production of mainly industrial waste. The effort to minimize these waste products is, therefore, no longer sufficient. Biotechnologists, therefore, started looking for ways to not only reuse these waste products, but also to valorise them. This work focuses on the biotechnological use and processing of waste oils/fats and waste glycerol by carotenogenic yeasts of the genus Rhodotorula and Sporidiobolus. The results of this work show that the selected yeast strains are able to process waste glycerol as well as some oils and fats in a circular economy model and, moreover, are resistant to potential antimicrobial compounds present in the medium. The best-growing strains, Rhodotorula toruloides CCY 062-002-004 and Rhodotorula kratochvilovae CCY 020-002-026, were selected for fed-batch cultivation in a laboratory bioreactor in a medium containing a mixture of coffee oil and waste glycerol. The results show that both strains were able to produce more than 18 g of biomass per litre of media with a high content of carotenoids (10.757 ± 1.007 mg/g of CDW in R. kratochvilovae and 10.514 ± 1.520 mg/g of CDW in R. toruloides, respectively). The overall results prove that combining different waste substrates is a promising option for producing yeast biomass enriched with carotenoids, lipids, and beta-glucans.
- Klíčová slova
- carotenogenic yeasts, carotenoids, lipids, waste animal fat, waste coffee oil, waste frying oil, waste glycerol, β-glucans,
- Publikační typ
- časopisecké články MeSH
Carotenogenic yeasts are a group of microorganisms producing valuable metabolites such as carotenoids, ergosterol, ubiquinone or fatty acids. Their exceptional adaptability allows them to grow in diverse conditions. Owing to their extracellular lipase activity, they are capable of processing many lipid-type waste substrates. This study discusses the processing of poultry waste, specifically fat and feathers by using carotenogenic yeasts. Poultry fat does not require any pre-treatment to be utilized by yeast, but hydrolytic pre-treatment is required for the utilization of the nitrogen contained in feathers. Glycerol was used as a supplementary substrate to support the culture in the early stages of growth. Seven yeast strains were used for the experiments, of which the strain Rhodotorula mucilaginosa CCY19-4-25 achieved exceptional results of biomass production: 29.5 g/L on poultry fat + 10% glycerol at C/N ratio 25 and 28.3 g/L on media containing poultry fat + 25% glycerol at C/N 50. The bioreactor cultivation of the Rhodosporidium toruloides strain in media containing glycerol and feather hydrolysate as a nitrogen substrate achieved a biomass yield of 34.92 g/L after 144 h of cultivation. The produced enriched yeast biomass can be used as a component for poultry feeding; thus, the study is performed under the biorefinery concept.
- Klíčová slova
- biorefinery, carotenogenic yeasts, carotenoids, enriched biomass, lipids, poultry feather, poultry waste fat,
- Publikační typ
- časopisecké články MeSH
One of the most addressed topics today is the transfer from a linear model of economics to a model of circular economics. It is a discipline that seeks to eliminate waste produced by various industries. The food industry generates huge amounts of waste worldwide, particularly the coffee industry, and related industries produce millions of tons of waste a year. These wastes have potential utility in biotechnology, and in the production of energy, fuels, fertilizers and nutrients, using green techniques such as anaerobic digestion, co-digestion, composting, enzymatic action, and ultrasonic and hydrothermal carbonization. This work is focused on the biotechnological use of processed spent coffee grounds (SCG) and waste fat/oil materials by some Sporidiobolus sp. carotenogenic yeasts in the model of circular economics. The results show that selected yeast strains are able to grow on SCG hydrolysate and are resistant to antimicrobial compounds present in media. The most productive strain Sporidiobolus pararoseus CCY19-9-6 was chosen for bioreactor cultivation in media with a mixture of coffee lignocellulose fraction and some fat wastes. Sporidiobolus pararoseus CCY19-9-6 was able to produce more than 22 g/L of biomass in mixture of SCG hydrolysate and both coffee oil and frying oil. The combined waste substrates induced the production of lipidic metabolites, whereby the production of carotenoids exceeded 5 mg/g of dry biomass. On media with coffee oil, this strain produced high amounts of ubiquinone (8.265 ± 1.648 mg/g) and ergosterol (13.485 ± 1.275 mg/g). Overall, the results prove that a combination of waste substrates is a promising option for the production of carotenoid- and lipid-enriched yeast biomass.
- Klíčová slova
- carotenogenic yeasts, carotenoids, coffee oil, lipids, spent coffee grounds hydrolysate, waste animal fat, waste frying oil,
- Publikační typ
- časopisecké články MeSH
The co-cultivation of red yeasts and microalgae works with the idea of the natural transport of gases. The microalgae produce oxygen, which stimulates yeast growth, while CO2 produced by yeast is beneficial for algae growth. Both microorganisms can then produce lipids. The present pilot study aimed to evaluate the ability of selected microalgae and carotenogenic yeast strains to grow and metabolize in co-culture. The effect of media composition on growth and metabolic activity of red yeast strains was assessed simultaneously with microalgae mixotrophy. Cultivation was transferred from small-scale co-cultivation in Erlenmeyer flasks to aerated bottles with different inoculation ratios and, finally, to a 3L bioreactor. Among red yeasts, the strain R. kratochvilovae CCY 20-2-26 was selected because of the highest biomass production on BBM medium. Glycerol is a more suitable carbon source in the BBM medium and urea was proposed as a compromise. From the tested microalgae, Desmodesmus sp. were found as the most suitable for co-cultivations with R. kratochvilovae. In all co-cultures, linear biomass growth was found (144 h), and the yield was in the range of 8.78-11.12 g/L of dry biomass. Lipids increased to a final value of 29.62-31.61%. The FA profile was quite stable with the UFA portion at about 80%. Around 1.98-2.49 mg/g CDW of carotenoids with torularhodine as the major pigment were produced, ubiquinone production reached 5.41-6.09 mg/g, and ergosterol yield was 6.69 mg/g. Chlorophyll production was very low at 2.11 mg/g. Pilot experiments have confirmed that carotenogenic yeasts and microalgae are capable of symbiotic co-existence with a positive impact om biomass growth and lipid metabolites yields.
- Klíčová slova
- Desmodesmus sp, Rhodotorula kratochvilovae, carotenogenic yeasts, carotenoids, co-cultivation, lipids, microalgae,
- Publikační typ
- časopisecké články MeSH
Beta (β)-glucans are polysaccharides composed of D-glucose monomers. Nowadays, β-glucans are gaining attention due to their attractive immunomodulatory biological activities, which can be utilized in pharmaceutical or food supplementation industries. Some carotenogenic Basidiomycetes yeasts, previously explored for lipid and carotenoid coproduction, could potentially coproduce a significant amount of β-glucans. In the present study, we screened eleven Basidiomycetes for the coproduction of lipids and β-glucans. We examined the effect of four different C/N ratios and eight different osmolarity conditions on the coproduction of lipids and β-glucans. A high-throughput screening approach employing microcultivation in microtiter plates, Fourier Transform Infrared (FTIR) spectroscopy and reference analysis was utilized in the study. Yeast strains C. infirmominiatum CCY 17-18-4 and R. kratochvilovae CCY 20-2-26 were identified as the best coproducers of lipids and β-glucans. In addition, C. infirmominiatum CCY 17-18-4, R. kratochvilovae CCY 20-2-26 and P. rhodozyma CCY 77-1-1 were identified as the best alternative producers of β-glucans. Increased C/N ratio led to increased biomass, lipid and β-glucans production for several yeast strains. Increased osmolarity had a negative effect on biomass and lipid production while the β-glucan production was positively affected.
- Klíčová slova
- carbon:nitrogen ratio, high-throughput screening, lipids, osmotic stress, red yeast, β-glucans,
- Publikační typ
- časopisecké články MeSH
BACKGROUND: Coronary heart disease (CHD) mortality has declined substantially in the Czech Republic over the last two decades. DESIGN: The purpose of this study was to determine what proportion of this CHD mortality decline could be associated with temporal trends in major CHD risk factors and what proportion with advances in medical and surgical treatments. METHODS: The validated IMPACT mortality model was used to combine and analyse data on uptake and effectiveness of CHD management and risk factor trends in the Czech Republic in adults aged 25-74 years between 1985 and 2007. The main sources were official statistics, national quality of care registries, published trials and meta-analyses, and the Czech MONICA and Czech post-MONICA studies. RESULTS: Between 1985 and 2007, age-adjusted CHD mortality rates in the Czech Republic decreased by 66.2% in men and 65.4% in women in the age group 25-74 years, representing 12,080 fewer CHD deaths in 2007. Changes in CHD risk factors explained approximately 52% of the total mortality decrease, and improvements in medical treatments approximately 43%. Increases in body mass index and in diabetes prevalence had a negative impact, increasing CHD mortality by approximately 1% and 5%, respectively. CONCLUSIONS: More than half of the very substantial fall in CHD mortality in the Czech Republic between 1985 and 2007 was attributable to reduction in major cardiovascular risk factors. Improvement in treatments accounted for approximately 43% of the total mortality decrease. These findings emphasize the value of primary prevention and evidence-based medical treatment.
- Klíčová slova
- Coronary heart disease, Czech MONICA and Czech post-MONICA, coronary heart disease management, coronary heart disease mortality, coronary heart disease risk factors,
- MeSH
- dospělí MeSH
- koronární nemoc mortalita MeSH
- lidé středního věku MeSH
- lidé MeSH
- rizikové faktory MeSH
- senioři MeSH
- senzitivita a specificita MeSH
- statistické modely MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika epidemiologie MeSH
BACKGROUND: The number of notified tuberculosis cases in the Czech Republic in 2009 was lower than in 2008. 710 new tuberculosis cases and relapses were reported. MATERIAL AND METHODS: 598 cases were pulmonary tuberculosis and from them 439 were proved pulmonary tuberculosis cases. In 2009 235 smear-positive cases of pulmonary tuberculosis were diagnosed. RESULTS: The incidence of tuberculosis was 6.8/100000 inhabitants in 2009. The percentage of tuberculosis cases diagnosed in foreign-born persons living in the Czech Republic increased from 14.2% in 2003 to 19.2% in 2009. CONCLUSIONS: Next targets of tuberculosis control in the Czech Republic must be an active case-finding in the high-risk groups and monitoring of latent tuberculosis infection.
- MeSH
- dítě MeSH
- dospělí MeSH
- incidence MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- plicní tuberkulóza epidemiologie MeSH
- předškolní dítě MeSH
- senioři MeSH
- tuberkulóza epidemiologie MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- předškolní dítě MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- anglický abstrakt MeSH
- časopisecké články MeSH
- Geografické názvy
- Česká republika epidemiologie MeSH
OBJECTIVES: To assess longitudinal trends in cardiovascular mortality and population mean blood pressure, prevalence, awareness, treatment, and control of hypertension in a representative Czech population sample from 1985 to 2007/2008. METHODS: Source data on mortality rates were provided by the Czech Statistical Office and further processed by the Institute for Health Information and Statistics of the Czech Republic. Six independent cross-sectional population surveys were conducted in 1985, 1988, 1992, 1997/1998, 2000/2001, and 2007/2008 with randomly selected men and women aged 25-64 years and resident in six districts of the Czech Republic (Praha-východ, Benešov, Pardubice, Chrudim, Cheb, and Jindřichův Hradec). The total number of participants was 13 972. RESULTS: Since 1985, there has been a significant continuous, almost linear decline in standardized total, cardiovascular disease, ischemic heart disease, and stroke mortality (P < 0.001).There was a significant downward trend in the population mean SBP (from 133.6 ± 20.2 to 129.5 ± 18.5 mmHg; P < 0.001) and DBP (from 84.1 ± 11.3 to 82.5 ± 10.0 mmHg; P < 0.001) from 1985 to 2007/2008. This was associated with a significant decrease in the prevalence of hypertension only in women (from 42.5 to 37.2%; P < 0.001). Awareness of hypertension increased in both sexes (men, from 41.4 to 68.4%; women, from 58.9 to 71.4%; both P < 0.001) as did the number of individuals on antihypertensive medication (men, from 21.1 to 58.2%, women: from 38.9 to 58.9%; both P < 0.001). Control of hypertension improved significantly (from 3.9 to 24.6%) over the same period. CONCLUSION: The reduction in population blood pressure and improved hypertension control may have contributed substantially to the decrease in cardiovascular disease mortality in the Czech Republic.
- MeSH
- dospělí MeSH
- hypertenze farmakoterapie epidemiologie mortalita patofyziologie MeSH
- kardiologie MeSH
- kardiovaskulární nemoci farmakoterapie epidemiologie mortalita patofyziologie MeSH
- krevní tlak MeSH
- lidé středního věku MeSH
- lidé MeSH
- longitudinální studie MeSH
- průřezové studie MeSH
- regresní analýza MeSH
- rizikové faktory MeSH
- senioři MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
