Most cited article - PubMed ID 30744842
Cranberries versus lingonberries: A challenging authentication of similar Vaccinium fruit
Anammox bacteria wield an energy-efficient nitrogen metabolism enveloped in anammoxosome organelle composed of unique ladderane lipids. Thus, waste anammox biomass seems to be an attractive target for the isolation of ladderanes and subsequent production of artificial vesicles for drug delivery. This study proposed a novel method to isolate ladderane-rich anammoxosomes from aggregate mixed culture of Ca. Brocadia sapporoensis. Compared to conventional isolation protocols, the protocol was simplified by omitting the prepurification of anammox cells, replacing Percoll® with a sucrose gradient and prolonging the application of EDTA. This enhanced and simplified procedure efficiently removed EPS and other debris, thus yielding the layer of anammoxosomes as confirmed by control experiments and TEM. For the first time, the resulting ladderane isolates were used for the preparation of liposomes, both with and without the addition of pure dipalmitoylphosphatidylcholine (DPPC). Vesicles were successfully created, characterised by TEM and DLS, and anammox-based ladderanes were incorporated into their walls. These liposomes had interesting functional properties such as increased colloid stability at elevated concentrations, meaning a reduced tendency to form aggregates compared to model liposomes made solely of DPPC. Overall, this study offers insights into converting waste anammox biomass into a valuable resource for drug delivery.
- Keywords
- Ca. Brocadia sapporoensis, anammox bacteria, anammoxosomes, artificial liposomes, ladderanes,
- MeSH
- Liposomes * chemistry metabolism isolation & purification MeSH
- Planctomycetes * MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- Liposomes * MeSH
Daunomycin is a chemotherapeutic agent widely used for the treatment of leukemia, but its toxicity toward healthy dividing cells limits its clinical use and its production by fermentation. Herein, we describe the development of a specialized cultivation medium for daunomycin production, including a shift to oil rather than sugar as the primary carbon source. This achieved an almost threefold increase in daunomycin yields, reaching 5.5-6.0 g/L. Daunomycin produced in the oil-based medium was predominantly found in the solid sediment, whereas that produced in the sugar-based medium was mostly soluble. The oil-based medium thus induces an autonomous daunomycin-resistance mechanism involving biogenic nanoparticle formation. The characterization of the nanoparticles confirmed the incorporation of iron and daunomycin, indicating that this approach has the potential to mitigate cytotoxicity while improving yields. The presence of proteins associated with iron homeostasis and oxidative stress responses revealed the ability of the production strain to adapt to high iron concentrations. Our findings provide insight into the mechanisms of biogenic nanoparticle formation and the optimization of cultivation processes. Further investigation will help to refine microbial production systems for daunomycin and also broaden the application of similar strategies for the synthesis of other therapeutically important compounds.
- Keywords
- Streptomyces coeruleorubidus, anthracyclines, daunomycin-iron organic complex, iron chelators, medium optimization, production strain development, vivianite,
- Publication type
- Journal Article MeSH
INTRODUCTION: Impact of processing on product characteristics, sustainability, traceability, authenticity, and public health along the food chain becomes more and more important not only to the producer but also to the customer and the trust of a consumer toward a brand. In recent years, the number of juices and smoothies containing so called super foods or fruits, which have been "gently pasteurized," has increased significantly. However, the term "gentle pasteurization" related to the application of emerging preservation technologies such as pulsed electric fields (PEF), high pressure processing (HPP) or ohmic heating (OH) is not clearly defined. METHODS: Therefore, the presented study investigated the influence of PEF, HPP, OH, and thermal treatment on quality characteristics and microbial safety of sea buckthorn syrup. Syrups from two different varieties were investigated under the following conditions HPP (600 MPa 4-8 min), OH (83°C and 90°C), PEF (29.5 kV/cm, 6 μs, 100 Hz), and thermal (88°C, hot filling). Analyses to test the influence on quality parameters like ascorbic acid (AA), flavonoids, carotenoids, tocopherols, antioxidant activity; metabolomical/chemical profiling (fingerprinting) via U-HPLC-HRMS/MS (here especially flavonoids and fatty acids); sensory evaluation, as well as microbial stability including storage, were conducted. RESULTS AND DISCUSSION: Independent from the treatment, the samples were stable over 8 weeks of storage at 4°C. The influence on the nutrient content [Ascorbic acid (AA), total antioxidant activity (TAA), total phenolic compounds (TPC), tocopherols (Vit E)] was similar for all tested technologies. Employing statistical evaluation Principal Component Analysis (PCA) a clear clustering based on the processing technologies was observed. Flavonoids as well as fatty acids were significantly impacted by the type of used preservation technology. This was obvious during the storage time of PEF and HPP syrups, where enzyme activity was still active. The color as well as taste of the syrups were found to be more fresh-like for the HPP treated samples.
- Keywords
- food quality, indicator compound, innovative food technologies, sea buckthorn, untargeted chemical fingerprinting,
- Publication type
- Journal Article MeSH
The adaptation of bacteria involved in anaerobic ammonium oxidation (anammox) to low temperatures will enable more efficient removal of nitrogen from sewage across seasons. At lower temperatures, bacteria typically tune the synthesis of their membrane lipids to promote membrane fluidity. However, such adaptation of anammox bacteria lipids, including unique ladderane phospholipids and especially shorter ladderanes with absent phosphatidyl headgroup, is yet to be described in detail. We investigated the membrane lipids composition (UPLC-HRMS/MS) and dominant anammox populations (16S rRNA gene amplicon sequencing, Fluorescence in situ hybridization) in 14 anammox enrichments cultivated at 10-37 °C. "Candidatus Brocadia" appeared to be the dominant organism in all but two laboratory enrichments of "Ca. Scalindua" and "Ca. Kuenenia". At lower temperatures, the membranes of all anammox populations were composed of shorter [5]-ladderane ester (reduced chain length demonstrated by decreased fraction of C20/(C18 + C20)). This confirmed the previous preliminary evidence on the prominent role of this ladderane fatty acid in low-temperature adaptation. "Ca. Scalindua" and "Ca. Kuenenia" had distinct profile of ladderane lipids compared to "Ca. Brocadia" biomasses with potential implications for adaptability to low temperatures. "Ca. Brocadia" membranes contained a much lower amount of C18 [5]-ladderane esters than reported in the literature for "Ca. Scalindua" at similar temperature and measured here, suggesting that this could be one of the reasons for the dominance of "Ca. Scalindua" in cold marine environments. Furthermore, we propose additional and yet unreported mechanisms for low-temperature adaptation of anammox bacteria, one of which involves ladderanes with absent phosphatidyl headgroup. In sum, we deepen the understanding of cold anammox physiology by providing for the first time a consistent comparison of anammox-based communities across multiple environments.
- Keywords
- Anaerobic ammonium oxidation, Candidatus Brocadia, Candidatus Scalindua, Effect of temperature, Ladderane phospholipids,
- MeSH
- Anaerobiosis MeSH
- Anaerobic Ammonia Oxidation * MeSH
- Bacteria * MeSH
- In Situ Hybridization, Fluorescence MeSH
- Membrane Lipids MeSH
- Oxidation-Reduction MeSH
- RNA, Ribosomal, 16S genetics MeSH
- Temperature MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- Membrane Lipids MeSH
- RNA, Ribosomal, 16S MeSH
Two alternative, complementary analytical strategies were successfully used to identify the most common meat species-beef, pork and chicken-in meat products. The first innovative high-throughput approach was based on triacylglycerols fingerprinting by direct analysis in real time coupled with high-resolution mass spectrometry (DART-HRMS). The second was the classic commonly used DNA analysis based on the use of nuclear or mitochondrial DNA in multiplex polymerase chain reaction (mPCR). The DART-HRMS method represents a rapid, high throughput screening method and was shown to have a good potential for the authentication of meat products. Nevertheless, it should be noted that due to a limited number of samples in this pilot study, we present here a proof of concept. More samples must be analyzed by DART-HRMS to build a robust classification model applicable for reliable authentication. To verify the DART-HRMS results, all samples were analyzed by PCRs. Good compliance in samples classification was documented. In routine practice under these conditions, screening based on DART-HRMS could be used for identification of suspect samples, which could be then examined and validated by accurate PCRs. In this way, saving of both labor and cost could be achieved. In the final phase, commercially available meat products from the Czech market were tested using this new strategy. Canned meats-typical Czech sausages and luncheon meats, all with declared content of beef, pork and chicken meat-were used. Compliance with the label declaration was confirmed and no adulteration was found.
- Keywords
- DNA, PCR, ambient mass spectrometry, authentication, meat, triacylglycerols,
- Publication type
- Journal Article MeSH