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Plant Communications Jun 2024
PubMed: 38909281
DOI: 10.1016/j.xplc.2024.101007 -
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 -
Environmental Research Jun 2024Urbanization of estuaries drastically changed existing shorelines and bathymetric contours, in turn modifying habitat for marine foundational species that host critical...
Urbanization of estuaries drastically changed existing shorelines and bathymetric contours, in turn modifying habitat for marine foundational species that host critical biodiversity. And yet we lack approaches to characterize a significant fraction of the biota that inhabit these ecosystems on time scales that align with rates of urbanization. Environmental DNA (or eDNA) metabarcoding that combines multiple assays targeting a broad range of taxonomic groups can provide a solution, but we need to determine whether the biological communities it detects ally with different habitats in these changing aquatic environments. In this study, we tested whether tree of life metabarcoding (ToL-metabarcoding) data extracted from filtered seawater samples correlated with four known geomorphic habitat zones across a heavily urbanized estuary (Sydney Harbour, Australia). Using this method, we substantially expanded our knowledge on the composition and spatial distribution of marine biodiversity across the tree of life in Sydney Harbour, particularly for organisms where existing records are sparse. Excluding terrestrial DNA inputs, we identified significant effects of both distance from the mouth of Sydney Harbour and geomorphic zone on biological community structure in the ToL-metabarcoding dataset (entire community), as well as in each of the taxonomic subgroups that we considered (fish, macroinvertebrates, algae and aquatic plants, bacteria). This effect appeared to be driven by taxa as a collective versus a few individual taxa, with each taxon explaining no more than 0.62% of the variation between geomorphic zones. Similarly, taxonomic richness was significantly higher within geomorphic zones with large sample sizes, but also decreased by 1% with each additional kilometer from the estuary mouth, a result consistent with a reduction in tidal inputs and available habitat in upper catchments. Based on these results, we suggest that ToL-metabarcoding can be used to benchmark biological monitoring in other urbanized estuaries globally, and in Sydney Harbour at future time points based on its detection of bioindicators across the tree of life. We also suggest that robust biotic snapshots can be archived following extensive curation of taxonomic assignments that incorporates their ecological affinities, supported by records from relevant and regional biodiversity repositories.
PubMed: 38906450
DOI: 10.1016/j.envres.2024.119454 -
Ecotoxicology and Environmental Safety Jun 2024Copper (Cu) is a necessary mineral nutrient for plant growth and development and is involved in several morphological, physiological, and biochemical processes; however,...
Integrated physiological, biochemical, and transcriptomic analyses of Bruguiera gymnorhiza leaves under long-term copper stress: Stomatal size, wax crystals and composition.
Copper (Cu) is a necessary mineral nutrient for plant growth and development and is involved in several morphological, physiological, and biochemical processes; however, high concentrations of Cu can negatively impact these processes. The role of stomata in responding to various biotic and abiotic stimuli has not been studied in Bruguiera gymnorhiza, particularly in terms of their coordinated interactions at the molecular, physiological, and biochemical levels. Moreover, numerous plants employ strategies such as the presence of thick waxy cuticles on their leaf epidermis and the closing of stomata to reduce water loss. Thus, this study investigates the accumulation of Cu in B. gymnorhiza and its effect on leaf morphology and the molecular response under different Cu treatments (0, 200, and 400 mg L⁻¹, Cu0, Cu200, and Cu400, respectively) during a two years stress period. The results show that Cu stress affected accumulation and transport, increased the activities of peroxidase and ascorbate peroxidase, concentrations of soluble sugar, proline, and HO, and decreased the activity of catalase and content of malondialdehyde. Also, Cu-induced stress decreased the uptake of phosphorus and nitrogen and inhibited plant photosynthesis, which consequently led to reduced plant growth. Scanning electron microscopy combined with gas chromatography-mass spectrometry showed that B. gymnorhiza leaves had higher wax crystals and compositions under increased Cu stress, which forced the leaf's stomata to be closed. Also, the contents of alkanes, alcohols, primary alcohol levels (C26:0, C28:0, C30:0, and C32:0), n-Alkanes (C29 and C30), and other wax loads were significantly higher, while fatty acid (C12, C16, and C18) was lower in Cu200 and Cu400 compared to Cu0. Furthermore, the transcriptomic analyses revealed 1240 (771 up- and 469 downregulated), 1000 (723 up- and 277 down-regulated), and 1476 (808 up- and 668 downregulated) differentially expressed genes in Cu0 vs Cu200, Cu0 vs Cu400, and Cu200 vs Cu400, respectively. RNA-seq analyses showed that Cu mainly affected eight pathways, including photosynthesis, cutin, suberin, and wax biosynthesis. This study provides a reference for understanding mangrove response to heavy metal stress and developing novel management practices.
PubMed: 38905937
DOI: 10.1016/j.ecoenv.2024.116609 -
Journal of Environmental Management Jun 2024In many industrial processes a large amount of water with high salinity is co-produced whose treatment poses considerable challenges to the available technologies. The...
In many industrial processes a large amount of water with high salinity is co-produced whose treatment poses considerable challenges to the available technologies. The produced water (PW) from offshore operations is currently being discharged to sea without treatment for dissolved pollutants due to space limitations. A biofilter on the seabed adjacent to a production platform would negate all size restrictions, thus reducing the environmental impact of oil and gas production offshore. The moving bed biofilm reactor (MBBR) was investigated for PW treatment from different oilfields in the North Sea at 10 °C and 40 °C, corresponding to the sea and PW temperature, respectively. The six PW samples in study were characterized by high salinity and chemical oxygen demand with ecotoxic effects on marine algae S. pseudocostatum (0.4%
PubMed: 38905793
DOI: 10.1016/j.jenvman.2024.121391 -
Frontiers in Microbiology 2024Nature exhibits an enormous diversity of organisms that thrive in extreme environments. From snow algae that reproduce at sub-zero temperatures to radiotrophic fungi... (Review)
Review
Nature exhibits an enormous diversity of organisms that thrive in extreme environments. From snow algae that reproduce at sub-zero temperatures to radiotrophic fungi that thrive in nuclear radiation at Chernobyl, extreme organisms raise many questions about the limits of life. Is there environment where life could not "find a way"? Although many individual extremophilic organisms have been identified and studied, there remain outstanding questions about the limits of life and the extent to which extreme properties can be enhanced, combined or transferred to new organisms. In this review, we compile the current knowledge on the bioengineering of extremophile microbes. We summarize what is known about the basic mechanisms of extreme adaptations, compile synthetic biology's efforts to engineer extremophile organisms beyond what is found in nature, and highlight which adaptations can be combined. The basic science of extremophiles can be applied to engineered organisms tailored to specific biomanufacturing needs, such as growth in high temperatures or in the presence of unusual solvents.
PubMed: 38903795
DOI: 10.3389/fmicb.2024.1341701 -
Journal of Advanced Pharmaceutical... 2024Millions of bacteria present in the mouth cavity contribute to the challenging management of oral mucosa injury. On the other hand, spp. (red algae) is one of the...
Millions of bacteria present in the mouth cavity contribute to the challenging management of oral mucosa injury. On the other hand, spp. (red algae) is one of the widely cultivated algae that have a strong potential as a wound-healing agent for oral mucosa injury. This study aimed to investigate the wound-healing property of the red algae by observing its effect on polymorphonuclear (PMN), a neutrophil that is usually recruited during the initial wound healing. The extract was obtained through maceration and used as bioactive ingredient in gel preparation. with incision wounds in the oral mucosa was used as the animal model. Our results revealed that rats treated with the red algae gel had significantly lower PMN on the injury site ( < 0.01) as observed on days 1, 3, and 5. Identification using gas chromatography-mass spectrometry showed that the extract was rich in hexadecenoic acid and glycerol. The brine shrimp lethality test suggested low cytotoxicity of this extract with LC = 10694.93 mg/mL. In conclusion, the extract could be potentially used as bioactive ingredient in gel formulation for topical management of oral mucosa wounds. Further, research to confirm these findings is warranted.
PubMed: 38903551
DOI: 10.4103/JAPTR.JAPTR_451_23 -
RSC Advances Jun 2024Marine endosymbionts have gained remarkable interest in the last three decades in terms of natural products (NPs) isolated thereof, emphasizing the chemical correlations...
Marine endosymbionts have gained remarkable interest in the last three decades in terms of natural products (NPs) isolated thereof, emphasizing the chemical correlations with those isolated from the host marine organism. The current study aimed to conduct comparative metabolic profiling of the marine red algae , and three fungal endosymbionts isolated from its inner tissues namely, , and . The ethyl acetate (EtOAc) extracts of the host organism as well as the isolated endosymbionts were analyzed using ultra-high performance liquid chromatography coupled to high resolution tandem mass spectrometry (UHPLC-MS/MS)in both positive and negative ion modes, applying both full scan (FS) and all ion fragmentation (AIF) modes. Extensive interpretation of the LC-MS/MS spectra had led to the identification of 76 metabolites belonging to different phytochemical classes including alkaloids, polyketides, sesquiterpenes, butyrolactones, peptides, fatty acids, isocoumarins, quinones, among others. Metabolites were tentatively identified by comparing the accurate mass and fragmentation pattern with metabolites previously reported in the literature, as well as bioinformatics analysis using GNPS. A relationship between the host and its endophytes (, , and ) was discovered. shares common metabolites with at least one of the three endosymbiotic fungi. Some metabolites have been identified in endophytes and do not exist in their host. Multivariate analysis (MVA) revealed discrimination of from and other associated endophytic fungi ( and ).
PubMed: 38903055
DOI: 10.1039/d4ra01055h -
Environmental Research Jun 2024Increasing amounts of wastewater is the most pervasive and challenging environmental problem globally. Conventional treatment methods are costly and entail huge energy... (Review)
Review
Increasing amounts of wastewater is the most pervasive and challenging environmental problem globally. Conventional treatment methods are costly and entail huge energy and carbon consumption and greenhouse gas emissions. Owing to their unique ability of carbon capturing and resource recovery, microalgae-microbiome based treatment is a potential approach and is widely used for carbon-neutral wastewater treatment. Microalgae-bacteria synergy (i.e., the functionally beneficial microbial synthetic communities) performs better and enhances carbon-sequestration and nutrient recovery from wastewater treatment plants. This review presents a comprehensive information regarding the potential of microalgae-microbiome as a sustainable agent for wastewater and discusses synergistic approaches for effective nutrient removal. Moreover, this review discusses, the role of omics-biology and Insilco approaches in unravelling and understanding the algae-microbe synergism and their response toward wastewater treatment. Finally, it discusses various microbiome engineering approaches for developing the effective microalgae-bacteria partners for carbon sequestration and nutrient recovery from wastewater, and summarizes future research perspectives on microalgae-microbiome based bioremediation.
PubMed: 38901811
DOI: 10.1016/j.envres.2024.119439 -
The Science of the Total Environment Jun 2024This study exposed a microalgal consortium formed by Auxenochlorella protothecoides, Tetradesmus obliquus, and Chlamydomonas reinhardtii to six mixed wastewater media...
This study exposed a microalgal consortium formed by Auxenochlorella protothecoides, Tetradesmus obliquus, and Chlamydomonas reinhardtii to six mixed wastewater media containing different proportions of primary (P) or secondary (S) effluents diluted in centrate (C). Algae could grow at centrate concentrations up to 50 %, showing no significant differences between effluents. After acclimation, microalgae cultivated in 50%P-50%C and 50%S-50%C grew at a rate similar to that of control cultures (0.59-0.66 d). These results suggest that the consortium acclimated to both sewage streams by modulating the proportion of the species and their metabolism. Acclimation also altered the photosynthetic activity of wastewater-grown samples compared to the control, probably due to partial photoinhibition, changes in consortium composition, and changes in metabolic activity. No major differences were observed between the two streams with respect to biochemical composition, biomass yield, or bioremediation capacity of the cultivated algae but algae grown in the secondary effluent showed qualitatively higher exopolysaccharides (EPS) production than algae grown in primary. Regarding wastewater remediation, microalgae grown in both WW media showed proficient nutrient removal efficiencies (close to 100 %); however, the final pH value (close to 11) would be controversial if the system were upscaled as it is over the legal limit and would cause phosphorus precipitation, so that CO addition would be required. The theoretical scale-up of the microalgae system could achieve water treatment costs of 0.109 €·m, which was significantly lower than the costs of typical activated sludge systems.
PubMed: 38901581
DOI: 10.1016/j.scitotenv.2024.174056