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Scientific Reports Jun 2024This study investigated the first-ever reported use of freshwater Nannochloropsis for the bioremediation of dairy processing side streams and co-generation of valuable...
This study investigated the first-ever reported use of freshwater Nannochloropsis for the bioremediation of dairy processing side streams and co-generation of valuable products, such as β-galactosidase enzyme. In this study, N. limnetica was found to grow rapidly on both autoclaved and non-autoclaved whey-powder media (referred to dairy processing by-product or DPBP) without the need of salinity adjustment or nutrient additions, achieving a biomass concentration of 1.05-1.36 g L after 8 days. The species secreted extracellular β-galactosidase (up to 40.84 ± 0.23 U L) in order to hydrolyse lactose in DPBP media into monosaccharides prior to absorption into biomass, demonstrating a mixotrophic pathway for lactose assimilation. The species was highly effective as a bioremediation agent, being able to remove > 80% of total nitrogen and phosphate in the DPBP medium within two days across all cultures. Population analysis using flow cytometry and multi-channel/multi-staining methods revealed that the culture grown on non-autoclaved medium contained a high initial bacterial load, comprising both contaminating bacteria in the medium and phycosphere bacteria associated with the microalgae. In both autoclaved and non-autoclaved DPBP media, Nannochloropsis cells were able to establish a stable microalgae-bacteria interaction, suppressing bacterial takeover and emerging as dominant population (53-80% of total cells) in the cultures. The extent of microalgal dominance, however, was less prominent in the non-autoclaved media. High initial bacterial loads in these cultures had mixed effects on microalgal performance, promoting β-galactosidase synthesis on the one hand while competing for nutrients and retarding microalgal growth on the other. These results alluded to the need of effective pre-treatment step to manage bacterial population in microalgal cultures on DPBP. Overall, N. limnetica cultures displayed competitive β-galactosidase productivity and propensity for efficient nutrient removal on DPBP medium, demonstrating their promising nature for use in the valorisation of dairy side streams.
Topics: beta-Galactosidase; Microalgae; Whey; Lactose; Stramenopiles; Fresh Water; Biodegradation, Environmental; Biomass; Nitrogen
PubMed: 38906947
DOI: 10.1038/s41598-024-65146-6 -
Communications Biology Jun 2024Dietary emulsifiers are linked to various diseases. The recent discovery of the role of gut microbiota-host interactions on health and disease warrants the safety...
Dietary emulsifiers are linked to various diseases. The recent discovery of the role of gut microbiota-host interactions on health and disease warrants the safety reassessment of dietary emulsifiers through the lens of gut microbiota. Lecithin, sucrose fatty acid esters, carboxymethylcellulose (CMC), and mono- and diglycerides (MDG) emulsifiers are common dietary emulsifiers with high exposure levels in the population. This study demonstrates that sucrose fatty acid esters and carboxymethylcellulose induce hyperglycemia and hyperinsulinemia in a mouse model. Lecithin, sucrose fatty acid esters, and CMC disrupt glucose homeostasis in the in vitro insulin-resistance model. MDG impairs circulating lipid and glucose metabolism. All emulsifiers change the intestinal microbiota diversity and induce gut microbiota dysbiosis. Lecithin, sucrose fatty acid esters, and CMC do not impact mucus-bacterial interactions, whereas MDG tends to cause bacterial encroachment into the inner mucus layer and enhance inflammation potential by raising circulating lipopolysaccharide. Our findings demonstrate the safety concerns associated with using dietary emulsifiers, suggesting that they could lead to metabolic syndromes.
Topics: Animals; Emulsifying Agents; Dysbiosis; Gastrointestinal Microbiome; Mice; Male; Metabolic Diseases; Mice, Inbred C57BL; Carboxymethylcellulose Sodium; Sucrose; Insulin Resistance; Lecithins
PubMed: 38902371
DOI: 10.1038/s42003-024-06224-3 -
Scientific Reports Jun 2024Feeding behavior, the most fundamental physiological activity, is controlled by two opposing groups of factors, orexigenic and anorexigenic factors. The sulfakinin...
Feeding behavior, the most fundamental physiological activity, is controlled by two opposing groups of factors, orexigenic and anorexigenic factors. The sulfakinin family, an insect analogue of the mammalian satiety factor cholecystokinin (CCK), has been shown to suppress food intake in various insects. Nevertheless, the mechanisms through which sulfakinin regulates feeding behavior remain a biological question. This study aimed to elucidate the signaling pathway mediated by the anorexigenic peptide sulfakinin in Bombyx mori. We identified the Bombyx mori neuropeptide G protein-coupled receptor A9 (BNGR-A9) as the receptor for sulfakinin through functional assays. Stimulation with sulfakinin triggered a swift increase in intracellular IP3, Ca, and a notable enhancement of ERK1/2 phosphorylation, in a manner sensitive to a Gα-specific inhibitor. Treatment with synthetic sulfakinin resulted in decreased food consumption and average body weight. Additionally, administering synthetic sulfakinin to silkworms significantly elevated hemolymph trehalose levels, an effect markedly reduced by pre-treatment with BNGR-A9 dsRNA. Consequently, our findings establish the sulfakinin/BNGR-A9 signaling pathway as a critical regulator of feeding behavior and hemolymph trehalose homeostasis in Bombyx mori, highlighting its roles in the negative control of food intake and the positive regulation of energy balance.
Topics: Animals; Bombyx; Trehalose; Hemolymph; Feeding Behavior; Homeostasis; Insect Proteins; Receptors, G-Protein-Coupled; Neuropeptides; Signal Transduction
PubMed: 38902334
DOI: 10.1038/s41598-024-65177-z -
PLoS Genetics Jun 2024Lager yeasts are limited to a few strains worldwide, imposing restrictions on flavour and aroma diversity and hindering our understanding of the complex evolutionary...
Lager yeasts are limited to a few strains worldwide, imposing restrictions on flavour and aroma diversity and hindering our understanding of the complex evolutionary mechanisms during yeast domestication. The recent finding of diverse S. eubayanus lineages from Patagonia offers potential for generating new lager yeasts with different flavour profiles. Here, we leverage the natural genetic diversity of S. eubayanus and expand the lager yeast repertoire by including three distinct Patagonian S. eubayanus lineages. We used experimental evolution and selection on desirable traits to enhance the fermentation profiles of novel S. cerevisiae x S. eubayanus hybrids. Our analyses reveal an intricate interplay of pre-existing diversity, selection on species-specific mitochondria, de-novo mutations, and gene copy variations in sugar metabolism genes, resulting in high ethanol production and unique aroma profiles. Hybrids with S. eubayanus mitochondria exhibited greater evolutionary potential and superior fitness post-evolution, analogous to commercial lager hybrids. Using genome-wide screens of the parental subgenomes, we identified genetic changes in IRA2, IMA1, and MALX genes that influence maltose metabolism, and increase glycolytic flux and sugar consumption in the evolved hybrids. Functional validation and transcriptome analyses confirmed increased maltose-related gene expression, influencing greater maltotriose consumption in evolved hybrids. This study demonstrates the potential for generating industrially viable lager yeast hybrids from wild Patagonian strains. Our hybridization, evolution, and mitochondrial selection approach produced hybrids with high fermentation capacity and expands lager beer brewing options.
Topics: Beer; Fermentation; Saccharomyces cerevisiae; Hybridization, Genetic; Saccharomyces; Ethanol; Mitochondria; Genome, Fungal; Evolution, Molecular; Genetic Variation; Maltose; Mutation
PubMed: 38900713
DOI: 10.1371/journal.pgen.1011154 -
Foods (Basel, Switzerland) May 2024This study reports on the physicochemical and sensory attributes, total phenolic content, and antioxidant activity of 36 honey samples produced by two different...
This study reports on the physicochemical and sensory attributes, total phenolic content, and antioxidant activity of 36 honey samples produced by two different stingless bee species ( and ) from Australia. The findings reveal moisture content across all samples ranges from 24.9% to 30.8% (/), electrical conductivity from 1.02 to 2.15 mS/cm, pH levels between 3.57 and 6.54, soluble solids from 69.2 to 75.1 °Brix, trehalulose concentrations from 6.20 to 38.2 g/100 g, fructose levels from 7.79 to 33.4 g/100 g, and glucose content from 3.36 to 26.8 g/100 g. Sucrose was undetectable in all investigated samples. In a sensory analysis involving 30 participants, Australian stingless bee honey was perceived as having a more pronounced sourness compared with New Zealand Manuka honey. The study reveals considerable variability in the composition of Australian stingless bee honey, influenced by factors such as floral availability, geographical origin, and time of harvest. It also demonstrates the presence of phenolic compounds and antioxidant activity in stingless bee honey, underlining their potential as a natural source of antioxidants. All investigated samples contain trehalulose, which supports the findings of other recent studies that propose this unusual disaccharide as a marker compound of stingless bee honey.
PubMed: 38890884
DOI: 10.3390/foods13111657 -
Foods (Basel, Switzerland) May 2024The adsorption characteristics of β-glucooligosaccharides on activated carbon and the purification were systematically investigated. The maximum adsorption capacity of...
The adsorption characteristics of β-glucooligosaccharides on activated carbon and the purification were systematically investigated. The maximum adsorption capacity of activated carbon reached 0.419 g/g in the optimal conditions. The adsorption behavior was described to be monolayer, spontaneous, and exothermic based on several models' fitting results. Five fractions with different degrees of polymerization (DPs) and structures of β-glucooligosaccharides were obtained by gradient ethanol elution. 10E mainly contained disaccharides with dp2a (G1→6G) and dp2b (G1→3G). 20E possessed trisaccharides with dp3a (G1→6G1→3G) and dp3b (G1→3G1→3G). 30E mainly consisted of dp3a and dp4a (G1→3G1→3(G1→6)G), dp4b (G1→6G1→3G1→3G), and dp4c (G1→3G1→3G1→3G). In addition to tetrasaccharides, 40E and 50E also contained pentasaccharides and hexasaccharides with β-(1→3)-linked or β-(1→6)-linked glucose residues. All fractions could inhibit the accumulation of intracellular reactive oxygen species (ROS) in HO-induced Caco-2 cells, and they could improve oxidative stress damage by increasing the activity of superoxide dismutase (SOD) and reduced glutathione (GSH), which were related to their DPs and structures. 50E with high DPs showed better anti-oxidative stress activity.
PubMed: 38890863
DOI: 10.3390/foods13111634 -
BMC Plant Biology Jun 2024Sucrose accumulation in sugarcane is affected by several environmental and genetic factors, with plant moisture being of critical importance for its role in the...
BACKGROUND
Sucrose accumulation in sugarcane is affected by several environmental and genetic factors, with plant moisture being of critical importance for its role in the synthesis and transport of sugars within the cane stalks, affecting the sucrose concentration. In general, rainfall and high soil humidity during the ripening stage promote plant growth, increasing the fresh weight and decreasing the sucrose yield in the humid region of Colombia. Therefore, this study aimed to identify markers associated with sucrose accumulation or production in the humid environment of Colombia through a genome-wide association study (GWAS).
RESULTS
Sucrose concentration measurements were taken in 220 genotypes from the Cenicaña's diverse panel at 10 (early maturity) and 13 (normal maturity) months after planting. For early maturity data was collected during plant cane and first ratoon, while at normal maturity it was during plant cane, first, and second ratoon. A total of 137,890 SNPs were selected after sequencing the 220 genotypes through GBS, RADSeq, and whole-genome sequencing. After GWAS analysis, a total of 77 markers were significantly associated with sucrose concentration at both ages, but only 39 were close to candidate genes previously reported for sucrose accumulation and/or production. Among the candidate genes, 18 were highlighted because they were involved in sucrose hydrolysis (SUS6, CIN3, CINV1, CINV2), sugar transport (i.e., MST1, MST2, PLT5, SUT4, ERD6 like), phosphorylation processes (TPS genes), glycolysis (PFP-ALPHA, HXK3, PHI1), and transcription factors (ERF12, ERF112). Similarly, 64 genes were associated with glycosyltransferases, glycosidases, and hormones.
CONCLUSIONS
These results provide new insights into the molecular mechanisms involved in sucrose accumulation in sugarcane and contribute with important genomic resources for future research in the humid environments of Colombia. Similarly, the markers identified will be validated for their potential application within Cenicaña's breeding program to assist the development of breeding populations.
Topics: Saccharum; Colombia; Sucrose; Genome-Wide Association Study; Humidity; Polymorphism, Single Nucleotide; Genotype
PubMed: 38886648
DOI: 10.1186/s12870-024-05233-y -
BMC Nephrology Jun 2024Hyperphosphatemia is associated with increased morbidity and mortality in patients with end-stage kidney disease (ESKD). Whereas clinical and observational studies have...
Management of serum phosphorus over a 1-year follow-up in patients on peritoneal dialysis prescribed sucroferric oxyhydroxide as part of routine care: a retrospective analysis.
BACKGROUND
Hyperphosphatemia is associated with increased morbidity and mortality in patients with end-stage kidney disease (ESKD). Whereas clinical and observational studies have demonstrated the effectiveness of sucroferric oxyhydroxide (SO) in controlling serum phosphorus (sP) in ESKD, data on the real-world impact of switching to SO in patients on peritoneal dialysis (PD) are limited. In this retrospective database analysis, we examine the impact of SO on sP management over a 1-year period among PD patients prescribed SO as part of routine clinical care.
METHODS
We analyzed de-identified data from adults on PD in Fresenius Kidney Care clinics who were prescribed SO monotherapy between May 2018 and December 2019 as part of routine clinical management. Changes from baseline in sP levels, phosphate binder (PB) pill burden, and laboratory parameters were evaluated during the four consecutive 91-day intervals of SO treatment.
RESULTS
The mean age of the 402 patients who completed 1 year of SO was 55.2 years at baseline, and they had been on PD for an average of 19.9 months. SO was initiated with no baseline PB recorded in 36.1% of patients, whereas the remaining 257 patients were switched to SO from sevelamer (39.7%), calcium acetate (30.4%), lanthanum (1.2%), ferric citrate (14.0%), or more than one PB (14.8%). Mean sP at baseline was 6.26 mg/dL. After being prescribed SO, the percentage of patients achieving sP ≤ 5.5 mg/dL increased from 32.1% (baseline) to 46.5-54.0% during the 1-year follow-up, whereas the mean number of PB pills taken per day decreased from 7.7 at baseline (among patients on a baseline PB) to 4.6 to 5.4. Serum phosphorus and PB pill burden decreased regardless of changes in residual kidney function over the 12-month period. Similar results were observed for the full cohort (976 patients who either completed or discontinued SO during the 1-year follow-up).
CONCLUSIONS
Patients on PD who were prescribed SO as part of routine care for phosphorus management experienced significant reductions in SP and PB pills per day and improvements in sP target achievement, suggesting the effectiveness of SO on SP management with a concurrent reduction in pill burden.
Topics: Humans; Middle Aged; Male; Retrospective Studies; Female; Ferric Compounds; Phosphorus; Peritoneal Dialysis; Hyperphosphatemia; Kidney Failure, Chronic; Follow-Up Studies; Sucrose; Drug Combinations; Aged; Adult
PubMed: 38886636
DOI: 10.1186/s12882-024-03633-8 -
Scientific Reports Jun 2024Floral nectar sugar composition is assumed to reflect the nutritional demands and foraging behaviour of pollinators, but the relative contributions of evolutionary and...
Floral nectar sugar composition is assumed to reflect the nutritional demands and foraging behaviour of pollinators, but the relative contributions of evolutionary and abiotic factors to nectar sugar composition remain largely unknown across the angiosperms. We compiled a comprehensive dataset on nectar sugar composition for 414 insect-pollinated plant species across central Europe, along with phylogeny, paleoclimate, flower morphology, and pollinator dietary demands, to disentangle their relative effects. We found that phylogeny was strongly related with nectar sucrose content, which increased with the phylogenetic age of plant families, but even more strongly with historic global surface temperature. Nectar sugar composition was also defined by floral morphology, though it was not related to our functional measure of pollinator dietary demands. However, specialist pollinators of current plant-pollinator networks predominantly visited plant species with sucrose-rich nectar. Our results suggest that both physiological mechanisms related to plant water balance and evolutionary effects related to paleoclimatic changes have shaped floral nectar sugar composition during the radiation and specialisation of plants and pollinators. As a consequence, the high velocity of current climate change may affect plant-pollinator interaction networks due to a conflicting combination of immediate physiological responses and phylogenetic conservatism.
Topics: Plant Nectar; Pollination; Biological Evolution; Phylogeny; Flowers; Sugars; Animals; Insecta; Sucrose; Europe; Magnoliopsida; Climate Change
PubMed: 38879632
DOI: 10.1038/s41598-024-64755-5 -
Food Research International (Ottawa,... Aug 2024Listeria monocytogenes, a widespread food-borne pathogen, utilizes diverse growth substrates including mono- and di-saccharides via PEP-phosphotransferase (PTS) systems....
Listeria monocytogenes, a widespread food-borne pathogen, utilizes diverse growth substrates including mono- and di-saccharides via PEP-phosphotransferase (PTS) systems. We evaluated a collection of L. monocytogenes isolates of different origins for their ability to utilize lactose, a disaccharide composed of galactose and glucose and the main carbon source in milk and dairy products. Notably, the dairy-associated outbreak strain F2365 could not utilize lactose efficiently, conceivably due to a frameshift mutation (lacR) resulting in a truncated LacR. Transcriptional activator LacR is involved in the expression of two PTS systems, encoded by the lpo operon lmo1718-1720 in combination with lmo2708 and the lmo2683-2685 operon, and linked to lactose and/or cellobiose metabolism in L. monocytogenes. Via experimental evolution of the ancestral strain F2365, an evolved isolate F2365 EV was obtained which showed enhanced growth and metabolism of lactose. Using the lactose-positive model strain L. monocytogenes EGDe as a control, HPLC experiments showed that EGDe and F2365 EV could consume lactose and utilize the glucose moiety, while the galactose moiety was exported from the cells. Genome sequencing of F2365 EV found the original lacR mutation was still present but an additional point mutation lmo2766 had occurred, resulting in an amino acid substitution in the putative regulator Lmo2766. The lmo2766 gene is located next to operon lmo2761-2765 with putative PTS genes in the genome. Notably, comparative RNAseq analysis confirmed that the lmo2761-2765 operon was strongly upregulated in F2365 EV in the presence of lactose but not in EGDe and F2365. Conversely, the LacR-regulated lpo operon, lmo2708, and lmo2683-2685 operon were only upregulated in EGDe. Additional growth and HPLC experiments, using mutants constructed in lactose-positive L. monocytogenes EGDe, showed reduced growth of the EGDe lacR mutant with no utilization of lactose, while the double mutant EGDe lacRlmo2766 showed enhanced growth and lactose utilization. Hence, these results demonstrate that an amino acid substitution in the Lmo2766 regulator activates a previously silent lactose utilization pathway encoded by PTS operon lmo2761-2765, facilitating the growth and metabolism of L. monocytogenes with lactose as a substrate. This finding enhances our understanding of the metabolic capabilities and adaptability of L. monocytogenes, offering a broader view of the lactose utilization capacity of this pathogen.
Topics: Listeria monocytogenes; Lactose; Operon; Bacterial Proteins; Disease Outbreaks; Gene Expression Regulation, Bacterial; Food Microbiology; Milk; Animals; Dairy Products
PubMed: 38876592
DOI: 10.1016/j.foodres.2024.114554