Phosphate Enrichment Research Articles

How do high phosphate concentrations affect soil microbial communities after a century of ecosystem self-reclamation?

The use of rock phosphate (RP) instead of soluble phosphate fertilizers is preferred for the development of more sustainable agriculture. However, the impact of high concentrations in RP on bacterial and fungal communities remains poorly documented. Thus, next-generation sequencing was used to characterize bacterial and fungal communities in the soils and roots of four plant species growing naturally in a self-restored ecosystem, on former open-pit phosphate mines where past exploitation generated locally a substantial phosphate enrichment of the soil. Our results show that bacterial communities are dominated by Actinobacteria and Proteobacteria phyla, while the Ascomycota and Basidiomycota phyla predominate in the fungal community. The alpha and beta diversities of both bacterial and fungal communities differ significantly between the root and soil compartments but are not significantly affected by RP inputs. However, Amplicon Sequence Variants (ASVs) indicative of RP-enriched soils have been identified; among them are bacteria representative of Streptomyces, Bacillus, Mycobacterium or Agromyces. Implications of these results open new ways of reflection to understand the microbial response following RP-inputs and long-term soil restoration, as well as to formulate microbial-based bioinoculants for sustainable agriculture applications based on microorganisms better adapted to high concentrations of RP.

Dolostone-barite-phosphorite sequence in the basal Doushantuo Formation: Origin and implications for post-Marinoan ocean chemistry and phosphogenesis

Barite (BaSO4) represents a major component of many post-Marinoan cap dolostones worldwide, recording important information on climate upheavals during the terminal Neoproterozoic. However, its origins and relations with other lithofacies remain to be explored. Here we report new occurrences of barite in the basal Ediacaran Doushantuo Formation at a major phosphate mine in Weng'an, South China, and present results of detailed petrographic and geochemical investigations on the barites and related phases. At the outcrop scale, barite is mainly present as a 1–2 cm-thick layer at the contact of the cap dolostones and overlying phosphorites. Detailed petrographic observations reveal a lithofacies transition from dolostone through a mixture of barite, dolomite and apatite to barite and finally to granular phosphorite. The barites can be categorized into three generations in stratigraphic order, which are present as loose, randomly-oriented blades (B1), dense aggregates (B2), and radially aligned crystal fans (B3), respectively. B1 is dispersed in a matrix of apatite and dolomite, which has an average δ13Ccarb of −0.61‰. This, along with the common presence of organic matter (OM) in this barite, point to a possible source of Ba from organic degradation. B3 forms a centimeter-scale layer of barite fans that laterally extends over the entire mining pit, whereas B2 is locally distributed between B1 and B3, and occurs as relatively unoriented aggregates. δ34S values of B3 show a narrow range between +25.9‰ and +30.9‰, which is similar to that of contemporaneous seawater and indicate a seawater source of sulfate in barite. Based on the present investigation and a compilation of published data, we propose that B1 is diagenetic barite with a main source of Ba from degradation of organic matter and possibly also from dissolution of previous pelagic barite, whereas B2 and B3 represent seafloor precipitates that resulted from interactions between deep, anoxic Ba-rich waters and oxic, sulfate-rich surface waters during the post-glacial transgression. This episode of barite precipitation was immediately followed by massive accumulations of phosphorites in Weng'an and many areas of South China. The consecutive deposition of cap dolostone, barite and phosphorite signifies the transition from an alkalinity-rich, stagnant anoxic ocean to a dynamic marine regime featuring oxygenated surface waters and upwelling currents. These pH and redox changes likely facilitated the cycling and enrichment of phosphate in the shallow waters that was necessitated by the unprecedented accumulation of Ediacaran phosphorites in South China.

Extreme iron cycling in a coastal lake-lagoon system driven by interactions between climate and entrance management

Intermittently closed and open coastal lakes and lagoons (ICOLLs) are ecologically important and hydrologically sensitive estuarine systems. We explore how extreme drought and ICOLL entrance management intersect to influence the geochemical cycling of iron. Opening the ICOLL entrance just prior to an extreme drought in 2019 led to prolonged extremely low water levels, thereby exposing intertidal/subtidal sulfidic sediments and causing oxidation of sedimentary pyrite. Subsequent reflooding of exposed sediments for ∼4 months led to extremely elevated Fe2+(aq) (>10 mM) in intertidal hyporheic porewaters, consistent with Fe2+(aq) release via pyrite oxidation and via reductive dissolution of newly-formed Fe(III) phases. Re-opening the ICOLL entrance caused a rapid fall in water levels (∼1.5 m over 7 d), driving the development of effluent groundwater gradients in the intertidal zone, thereby transporting Fe2+-rich porewater into surface sediments and surface waters. This was accompanied by co-mobilisation of some trace metals and nutrients. On contact with oxic, circumneutral-pH estuarine water, the abundant Fe2+(aq) oxidised, forming a spatially extensive accumulation of poorly crystalline Fe(III) oxyhydroxide floc (up to 25 % Fe dry weight) in shallow intertidal zone benthic sediments throughout the ICOLL. Modelling estimates ∼4050 × 103 kg of poorly-crystalline Fe was translocated into surficial sediments. The newly formed Fe(III)-oxyhydroxides serve as a metastable sink encouraging enrichment of both phosphate and various trace metal(loid)s in near-surface sediments, which may have consequences for future cycling of nutrients, metals and ICOLL ecological function. The additional Fe also may enhance ICOLL sensitivity to similar future drought events by encouraging pyrite formation in shallow (<5 cm) benthic sediments. This system-wide translocation of Fe from deeper sediments into surficial benthic sediments represents a form of geochemical hysteresis with an uncertain recovery trajectory. This study demonstrates how climate extremes can interact with anthropogenic management to amplify ICOLL hydrological oscillations and influence biogeochemistry in complex ways.

Influence of operation sequences on phosphorus recovery by polyphosphate-accumulating organisms biofilm: Performance, kinetics and metabolic response

Two biofilm sequencing batch reactors (BSBRs) were conducted under alternating aerobic/anaerobic (Ae/An) sequence and alternating anaerobic/aerobic (An/Ae) sequence to investigate the effects of operation sequences on phosphorus removal and recovery performance. The Ae/An BSBR had advantages in phosphate enrichment, phosphorus concentration of enrichment solution can reach 99.08 mg/L. While An/Ae BSBR exhibited a higher kinetic rate for phosphate uptake and release up to 0.48 mmol/gVSS. In An/Ae BSBR, the remarkable increase of phosphate concentration in aerobic stage put a great strain on the phosphate uptake of biofilms that led to an increase of phosphorus accumulation in the biofilm (Pbiofilm). However, the poly-P proportion in TPbiofilm decreased which triggered the metabolisim of polyphosphate accumulating organisms (PAOs) shifting from polyphosphate accumulating metabolism (PAM) to glycogen accumulating metabolism (GAM) and suppressed the phosphorus enrichment performance of the An/Ae BSBR. The phosphate uptake rate (PUR) of biofilms was in alignment with the bulk phosphate concentration. PAOs were dominated by Rhodoplanes and Saprospiraceae in the Ae/An BSBR, whereas Thiothrix was predominant in the An/Ae BSBR. Notably, the Candidatus Competibacter, considered as a denitrifying glycogen accumulating organisms (DGAOs), showed a dominant proportion in the microbial community of both BSBRs. The higher expression of actP in the An/Ae system indicated a greater capacity for the uptake of acetate, while the Ae/An system was is more adept for degrading acetate represented by the higher relative abundance of ackA, pta and acsA genes The high phosphorus loading in the An/Ae system suppressed the ppk expression but enhanced the ppx expression.

Enrichment and Bioavailability of Phosphate in a Highly Urbanized Zone of Cochin Estuary, South India

ABSTRACT Sequential extraction (SEDEX method) was employed to explore the distribution of sediment-bound phosphorus (P) fractions and the bioavailability of P in Cochin estuary. Concentration of P fractions in surface sediments of the study area ranged as follows: Detrital P > Organic P > Authigenic P > Exchangeable P > Iron-bound P. Generally increasing trend was displayed by all the phosphate fractions toward the downstream sites due to effluent discharges from industrial, domestic, municipal, agricultural sectors and destruction of mangrove forests. The elevated levels of inorganic phosphorus (133.55–918.73 mg/kg) reflected the large-scale delivery of sediment loads associated with great floods during 2018 & 2019. Significant correlations of fine-grained sediment particles with all phosphate fractions indicated surface adsorption as a dominant distribution mechanism. Concentration of iron-bound phosphorus was controlled by adsorption on iron oxy-hydroxides. The buildup of bioavailable phosphate (range: 23.76 to 49.97%) indicate the fact that the estuarine sediments function as a sink for the nutrient. The upper and middle part of the study area recorded more severe contamination and eutrophication risk as indicated by phosphorous pollution index (range: 0.31 to 2.56).

Cultivation of phosphate-accumulating biofilm: Study of the effects of acyl-homoserine lactones (AHLs) and cyclic dimeric guanosine monophosphate (c-di-GMP) on the formation of biofilm and the enhancement of phosphate metabolism capacity

This study investigated the mechanisms of microbial growth and metabolism during biofilm cultivation in the biofilm sequencing batch reactor (BSBR) process for phosphate (P) enrichment. The results showed that the sludge discharge was key to biofilm growth, as it terminated the competition for carbon (C) source between the nascent biofilm and the activated sludge. For the tested reactor, after the sludge discharge on 18 d, P metabolism and C source utilization improved significantly, and the biofilm grew rapidly. The P concentration of the recovery liquid reached up to 157.08 mg/L, which was sufficient for further P recovery via mineralization. Meta-omics methods were used to analyze metabolic pathways and functional genes in microbial growth during biofilm cultivation. It appeared that the sludge discharge activated the key genes of P metabolism and inhibited the key genes of C metabolism, which strengthened the polyphosphate-accumulating metabolism (PAM) as a result. The sludge discharge not only changed the types of polyphosphate-accumulating organisms (PAOs) but also promoted the growth of dominant PAOs. Before the sludge discharge, the necessary metabolic abilities that were spread among different microorganisms gradually concentrated into a small number of PAOs, and after the sludge discharge, they further concentrated into Candidatus_Contendobacter (P3) and Candidatus_Accumulibacter (P17). The messenger molecule C-di-GMP, produced mostly by P3 and P17, facilitated P enrichment by regulating cellular P and C metabolism. The glycogen-accumulating organism (GAO) Candidatus_Competibacter secreted N-Acyl homoserine lactones (AHLs), which stimulated the secretion of protein in extracellular polymeric substances (EPS), thus promoting the adhesion of microorganisms to biofilm and improving P metabolism via EPS-based P adsorption. Under the combined action of the dominant GAOs and PAOs, AHLs and C-di-GMP mediated QS to promote biofilm development and P enrichment. The research provides theoretical support for the cultivation of biofilm and its wider application.

Variability of the trophic state in a coastal reef system associated with submarine groundwater discharge in the Mexican Caribbean.

Submarine groundwater discharges (SGD) have been associated with important sources of nutrients between the land and oceans that can generate eutrophication conditions. This study aims to analyze the behavior of nitrogen and phosphorus using the mixing curve method, to examine the variation of the trophic state using the Karydis Index, and to evaluate the δ15N in benthic organisms to trace the origin of nitrogen in neap tide (November) and spring tide (January) in the Manatí Cenote, and Nohoch-Teek reef lagoon in the Mexican Caribbean. Nitrogen and phosphate enrichment was in the Manatí Cenote during neap and spring tides. This enrichment was particularly noticeable in the reef lagoon during low tides in the areas influenced by SGD. In the Cenote, differences in the nitrate trophic state were observed, indicating an eu-mesotrophic condition during neap tide and a mesotrophic condition during spring tide. However, no significant differences were observed for ammonium (oligo-mesotrophic), nitrites, or phosphate compounds (oligotrophic). The trophic state reef lagoon exhibited a similar pattern but with different spatial variations. In both systems, phosphorus was a limiting nutrient, while δ15N suggested anthropogenic nitrogen uptake by several benthic organisms.

Simplification of the pretreatment method for phosphate oxygen isotope measurement in phosphogypsum leachate

The stacking of phosphogypsum has caused considerable phosphorus pollution in water bodies near phosphogypsum yards through surface runoff and underground infiltration. The phosphate oxygen isotope (δ18Op) tracing method has served as a valuable tool for tracing phosphorus pollution in water. However, the existing δ18Op enrichment and purification methods are complex, costly, and inefficient for phosphate recovery, particularly for phosphogypsum leachate with complex compositions. Herein, a simplified and optimized pretreatment method for δ18Op measurement in phosphogypsum leachate was developed. Zirconium/polyvinyl alcohol (Zr/PVA) gel beads showed good selectivity for phosphate enrichment from water at different initial phosphate concentrations with appropriate Zr/PVA dosage. The optimal enrichment pH value was <7, and the concentrated phosphate on the Zr/PVA gel beads could be effectively eluted in an alkaline environment. Compared with the traditional Fe or Mg coprecipitation enrichment methods, impurities in the solution showed no obvious adverse effects on the phosphate enrichment process. Further, the phosphate solution eluted from the Zr/PVA gel beads was purified by a simple adjustment of the pH instead of cation exchange in the traditional purification process. Magnesium ions in the solution could be completely removed when the pH ranged from 3.17 to 6.15, and the phosphate recovery rate could reach 98.66% when the eluent pH was 5.02. Fourier-transform infrared spectroscopy, X-ray diffraction, and energy-dispersive X-ray spectroscopy revealed that similar to traditional pretreatment method, the proposed method can obtain high-purity Ag3PO4 solids for δ18OP measurement and no isotope fractionation of δ18OP was observed. Therefore, this study provides a promising and reliable pretreatment method for δ18OP measurement, especially in complex phosphogypsum leachate.

Volcanism-driven lacustrine redox fluctuations were responsible for the formation of the Jehol Lagerstätte: Evidence from a high-resolution Aptian sedimentary core, Northeast China

While a “volcanic Pompeii” model is well accepted as the cause of mass mortality and exceptional preservation of the Jehol Biota, no consensus has been reached thus far regarding the cause of mass mortality of fossils found in interbedded finely laminated sediments. We propose that volcanically driven, lacustrine redox fluctuations were responsible for the formation of the Jehol Lagerstätte, based on data obtained from a new drill core of Lower Cretaceous sedimentary rocks in the Chaoyang Basin, Northeast China. We found manganese-rich carbonates are interbedded with molybdenum-rich black mudstones and tuffs, and phosphatized fossils in the drill core. The elemental enrichment factors for molybdenum are much higher than for uranium in the black mudstones, suggesting the role of the manganese particulate-shuttle in deposition of this element. The manganese-rich carbonates are formed by the reaction of manganese oxides with organic matter, indicating an oxidized water column. This process accelerates the enrichment of molybdenum under anoxic non-sulfidic conditions. The interbedded manganese carbonates and molybdenum-rich mudstones thus record redox fluctuations in the lacustrine depositional environment. Given the numerous tephra in the black mudstones and soft-sediment deformation structures ostensibly associated with seismicity, we propose that the redox fluctuations were caused by lake eutrophication and turnover driven by volcanism that was ultimately related to the destruction of the North China Craton. These volcanically induced redox fluctuations, along with the toxicity of the volcanic gases, may have caused the simultaneous mass mortality of aquatic, terrestrial, and avian fauna. Micro-X-ray fluorescence, energy dispersive X-ray spectroscopy, and Raman mapping show that the preservation of fossils was mainly due to phosphatization. Fluctuating redox conditions facilitated phosphate enrichment in sediments. Both the oxic and anoxic non-sulfidic conditions were conducive to the preservation of organisms by phosphatization, and oxidation was favorable for phosphate mineralization, both contributing to the exceptional preservation of the Jehol Biota fossils.

Metagenomics, metatranscriptomics, and proteomics reveal the metabolic mechanism of biofilm sequencing batch reactor with higher phosphate enrichment capacity under low phosphorus load

The biofilm sequencing batch reactor (BSBR) process has higher phosphate recovery efficiency and enrichment multiple when the phosphorus load is lower, but the mechanism of phosphate enrichment at low phosphorus load remains unclear. In this study, we operated two BSBR operating under low and high phosphorus load (0.012 and 0.032 kg/(m3·d)) respectively, and used metagenomic, metatranscriptomic, and proteomics methods to analyze the community structure of the phosphorus accumulating organisms (PAOs) in the biofilm, the transcription and protein expression of key functional genes and enzymes, and the metabolism of intracellular polymers. Compared with at high phosphorus load, the BSBR at low phosphorus load have different PAOs and fewer types of PAOs, but in both cases the PAOs must have the PHA, PPX, Pst, and acs genes to become dominant. Some key differences in the metabolism of PAOs from the BSBR with different phosphorus load can be identified as follows. When the phosphorus load is low, the adenosine triphosphoric acid (ATP) and NAD(P)H in the anaerobic stage come from the TCA cycle and the second half of the EMP pathway. The key genes that are upregulated include GAPDH, PGK, ENO, ppdk in the EMP pathway, actP in acetate metabolism, phnB in polyhydroxybutyrate (PHB) synthesis, and aceA, mdh, sdhA, and IDH1 in the TCA cycle. In the meantime, the ccr gene in the PHV pathway is inhibited. As a result, the metabolism of the PAOs features low glycogen with high PHB, Pupt, Prel, and low PHV. That is, more ATP and NAD(P)H flow to phosphorus enrichment metabolism, thus allowing the highly efficient enrichment of phosphorus from low concentration phosphate thanks to the higher abundance of PAOs. The current results provide theoretical support and a new technical option for the enrichment and recovery of low concentrations of phosphate from wastewater by the BSBR process.

Spectroscopic and Surface Complexation Modeling of Phosphate Enrichment on Porous Iron-Carbon Composites

Spectroscopic and Surface Complexation Modeling of Phosphate Enrichment on Porous Iron-Carbon Composites

Organic waste recycling by vermicomposting amended with rock phosphate impacts the stability and maturity indices of vermicompost

ABSTRACT Recycling organic waste can help the land be nourished, properly disposed of, and protected from the negative impacts of chemical fertilizers. Organic additions like vermicompost can help restore and preserve the quality of the soil, however, producing vermicompost of a high enough standard is difficult. This study was planned to prepare vermicompost by utilizing two different organic wastes viz. household waste and organic residue amended with rock phosphate and further evaluate their stability and maturity indices during vermicomposting for quality of produce. For this study, the organic wastes were collected and vermicompost was prepared by using earthworm (Eisenia fetida) and with or without enriching with rock phosphate. Results showed that pH, bulk density, and biodegradability index were decreased and water holding capacity and cation exchange capacity was increased with the gradual progress of composting starting from 30 to 120 days of sampling/composting (DAS). Initially (upto 30 DAS) water-soluble carbon and water-soluble carbohydrate increased with rock phosphate enrichment. The population of the earthworms and enzymatic activities (CO2 evolution, dehydrogenase, and alkaline phosphatase) were also increased on enriching with rock phosphate and with the progression of the composting period. Rock phosphate addition (enrichment) also reflected the higher content of phosphorus (106% and 120% for household waste and organic residue, respectively) in the final product of vermicompost. The vermicompost prepared from household waste and enriched with rock phosphate showed greater maturity and stability indices. Overall, this can be concluded that the maturity and stability of vermicompost depend on the substrate used and improves on enriching with rock phosphate. Implications: Our study concludes that the quality of vermicompost depends on different substrates, composting period, and enrichment with rock phosphate. The qualities of vermicompost were best found under household waste-based vermicompost enriched with rock phosphate. The efficiency of vermicomposting process using earthworms was found maximum for enriched and without enriched household-based vermicompost. The study also indicated that several stability and maturity indices are influenced by different parameters and hence cannot be determined by a single parameter. The addition of rock phosphate increased the cation exchange capacity, phosphorus content, and alkaline phosphatase. Nitrogen, zinc, manganese, dehydrogenase, and alkaline phosphatase were found higher under household waste-based vermicompost relative to organic residue-based vermicompost. All four substrates promoted earthworm growth and reproduction in vermicompost.

LIBS-MLIF Method: Stromatolite Phosphorite Determination

The search for biominerals is one of the core targets in the deep space exploration mission. Stromatolite phosphorite is a typical biomineral that preserves early life on Earth. The enrichment of phosphate is closely related to microorganisms and their secretions. Laser-induced breakdown spectroscopy (LIBS) has become an essential payload in deep space exploration with the ability to analyze chemical elements remotely, rapidly, and in situ. This paper aims to evaluate the rapid identification of biological and non-biological minerals through a remote LIBS payload. LIBS is used for element analysis and mineral classification determination, and molecular laser-induced fluorescence (MLIF) is used to detect halogenated element F to support the existence of fluorapatite. This paper analyzes the LIBS-MLIF spectral characteristics of stromatolites and preliminarily evaluates the feasibility of P element quantification. The results show that LIBS technology can recognize biological and non-biological signals. This discovery is significant because it is not limited to detecting and analyzing element composition. It can also realize the detection of molecular spectrum based on selective extraction of CaF molecule. Therefore, the LIBS payload still has the potential to search for biomineral under the condition of adjusting the detection strategy.

A new insight in enhancing phosphate enrichment in biofilm process: Comparison of the key metabolic pathways in highly-efficient and dominant PAOs based on metagenomics

The formation of dominant phosphate-accumulating organisms (PAOs) is essential for the high enrichment of phosphate in biofilm sequencing batch reactors (BSBR) for phosphorus recovery. The dominant PAOs in the biofilm process have not been isolated and purified, and the key metabolic pathways that promote the formation of dominant PAOs are still unclear. In this study, four strains of highly-efficient PAOs were obtained by an innovative isolation procedure. The relationship between the abundance of highly-efficient and dominant PAOs and the phosphate removal ability was compared. We found that the abundance of PAOs was positively correlated with the phosphate removal efficiency in vitro pure culture and complex biofilm process. Metagenomics analysis revealed that compared with highly-efficient PAOs cultured in vitro, dominant PAOs in biofilms had unique key metabolic pathways, F-ATPases and N-Acyl homoserine lactones (AHLs). F-ATPases are important for maintaining the proton motive force (PMF) required for the uptake of carbon sources by PAOs, and AHLs are participating in phosphate metabolism through quorum sensing (QS) mediated secretion of extracellular polymeric substance (EPS). The formation of dominant PAOs was promoted by optimizing carbon source uptake and phosphate metabolism. This study revealed that the difficult isolation of dominant PAOs was due to the AHLs-mediated QS, and we identified the key pathways regulating the formation of dominant PAOs in biofilms through genomics analysis. Our findings provide insights in enhancing phosphate enrichment in BSBR by modulating the components of microbial community under the low concentration of carbon source consumption.

Isolation, Identification, and Characterization of Phosphate-Solubilizing Bacteria from Tunisian Soils

Soil microorganisms play an important role in maintaining natural ecological balance through active participation in carbon, nitrogen, sulfur, and phosphorous cycles. Phosphate-solubilizing bacteria (PSB) are of high importance in the rhizosphere, enhancing the solubilization of inorganic phosphorus complexes into soluble forms available for plant nutrition. The investigation of this species of bacteria is of major interest in agriculture, as they can be used as biofertilizers for crops. In the present study, 28 isolates of PSB were obtained after the phosphate enrichment of soil samples from five Tunisian regions. Five PSB species were identified by 16S rRNA gene sequencing including Pseudomonas fluorescens, P. putida, and P. taiwanensis, Stenotrophomonas maltophilia, and Pantoea agglomerans. Solid and liquid Pikovskaya's (PVK) and National Botanical Research Institute's (NBRIP) media containing insoluble tricalcium phosphate were used for the evaluation of the phosphate solubilization ability of the bacterial isolates by two methods: visual evaluation of the solubilization zone around colonies (halo) and determination of solubilized phosphates in liquid medium by the colorimetric method of the vanado-molybdate yellow. Based on the results of the halo method, the isolate of each species that showed the higher phosphate solubilization index was selected for evaluation of phosphate solubilization by the colorimetric method. In the liquid media, the bacterial isolates showed phosphate solubilization ranging from 535.70 to 618.57 µg mL-1 in the NBRIP medium, and 374.20 to 544.28 µg mL-1 in the PVK medium, with the highest values produced by P. fluorescens. The best phosphate solubilization ability and higher reduction in broth pH, which indicates higher organic acid production, were achieved in NBRIP broth for most of the PSB. Strong correlations were observed between the average capability of PSB to solubilize phosphates and both the pH and total phosphorous content in the soil. The production of the hormone indole acetic acid (IAA), which can promote plant growth, was observed for all five PSB species. Among them, P. fluorescens obtained from the forest soil of northern Tunisia showed the highest production of IAA (50.4 ± 0.9 µg mL-1).

Paleoenvironmental Study of the Late Cretaceous–Eocene Tethyan Sea Associated with Phosphorite Deposits in Jordan

Petrological, geochemical, and biostratigraphical investigations have been conducted on seventy-nine samples from four selected sections in Jordan to understand the factors that influenced the enrichment and deposition of massive phosphorite deposits. The calcareous nannofossil marker species Broisonia parca constrica and Reticulofenestra bisecta, from the assigned sections 1 and 2 (Hawar and Al Dhahikiyya), were indicative of the Campanian and Eocene periods, respectively. The enrichment of some ecological marker species such as Kamptnerius magnificus indicates that there were cold periods during phosphate precipitation. All thin sections of the phosphate samples are of grainstone and packstone textures and are composed of skeletal fragments and peloids. Skeletal fragments appeared to be the main component of Hawar phosphates with the existence of peloids, while peloids were the component in sections 2 and 3 (section 3: Al Hisa). At least three intervals of high phosphorous values appeared in the Hawar section, showing variations in the Ca and Nd isotopes and in the terrigenous inputs. Four periods of phosphate enrichment are observed in Sections 2 and 3. These are deep water circulation periods of the early and late Campanian period, interrupted by two periods of submarine and continental weathering. Deep water circulation was initiated during cooling in the Campanian period and indicated by high phosphorous and Ca isotope components and a decline in terrigenous indicators (Al, Si, Ti, and Fe). Submarine weathering during warmer deep-sea periods is indicated by a rising Nd isotope ratio when many of the igneous provinces were subjected to weathering. Continental weathering took place in the warmer periods, with the hydrologic cycle and enhancement of terrigenous indicators (Al, Si, Ti, and Fe) being observed. The effect of the hydrologic cycle was at its highest in the south during the Campanian period and in the Eocene, as both represented shallower settings.

The Effect of Combination of Nitrogen and Phosphate Enrichment on the Development of Seaweed Spores (Kappaphycus alvarezii)

Seaweed (Kappaphycus alvarezii) is one of the aquatic commodities that has the potential to be developed due to demand reaching the international market (Ari, SP and Risna Yusuf, 2018). Provision of seeds is still carried out by vegetative means (cuttings) (Runtuboy N and Slamet Abadi, 2018). However, there are problems, especially the provision of quality seeds, large scale, and does not depend on the season. Provision of seeds can also be done generatively. K. alvarezii can be developed by exploiting the nature of sexual reproduction through the development of spores which are characterized by the presence of cystocarp on the surface of the thallus (Juniarta I, 2016). However, the cystocarp in its growth really needs nutrition in order to produce spores of good quality and quantity. The nutrients needed are nitrogen and phosphate. This is due to the role of nitrogen as a constituent of protein and phosphate as a provider of energy (Pauwah A, et al., 2020). The purpose of this study was to determine the dose ratio of nitrogen and phosphate enrichment on cystocarp development. The research was carried out from November 2018 to February 2019, at the Seaweed Laboratory of the Takalar Brackish Water Aquaculture Fishery Center (BPBAPT). The study contained 6 treatments with 3 repetitions, namely Treatment A = Without enrichment (SW), Treatment B = 0.5 ppm N: 0.5 ppm P, Treatment C = 1 ppm N: 0.5 ppm P, Treatment D = 1.5 ppm N : 0.5 ppm P, Treatment E = 0.5 ppm N : 1 ppm P, and Treatment F = 0.5 ppm N : 1.5 ppm P. The results showed that the highest germination was in treatment D with an average of 56.95%. However, the research was not significantly different between treatments (p&gt;0.05).

The widely distributed soft coral Xenia umbellata exhibits high resistance against phosphate enrichment and temperature increase

Both global and local factors affect coral reefs worldwide, sometimes simultaneously. An interplay of these factors can lead to phase shifts from hard coral dominance to algae or other invertebrates, particularly soft corals. However, most studies have targeted the effects of single factors, leaving pronounced knowledge gaps regarding the effects of combined factors on soft corals. Here, we investigated the single and combined effects of phosphate enrichment (1, 2, and 8 μM) and seawater temperature increase (26 to 32 °C) on the soft coral Xenia umbellata by quantifying oxygen fluxes, protein content, and stable isotope signatures in a 5-week laboratory experiment. Findings revealed no significant effects of temperature increase, phosphate enrichment, and the combination of both factors on oxygen fluxes. However, regardless of the phosphate treatment, total protein content and carbon stable isotope ratios decreased significantly by 62% and 7% under temperature increase, respectively, suggesting an increased assimilation of their energy reserves. Therefore, we hypothesize that heterotrophic feeding may be important for X. umbellata to sustain their energy reserves under temperature increase, highlighting the advantages of a mixotrophic strategy. Overall, X. umbellata shows a high tolerance towards changes in global and local factors, which may explain their competitive advantage observed at many Indo-Pacific reef locations.

Phosphate enrichment increases the resilience of the pulsating soft coral Xenia umbellata to warming

Hard corals are in decline as a result of the simultaneous occurrence of global (e.g., ocean warming) and local (e.g., inorganic eutrophication) factors, facilitating phase shifts towards soft coral dominated reefs. Yet, related knowledge about soft coral responses to anthropogenic factors remains scarce. We thus investigated the ecophysiological response of the pulsating soft coral Xenia umbellata to individual and combined effects of phosphate enrichment (1, 2, and 8 μM) and ocean warming (26 to 32°C) over 35 days. Throughout the experiment, we assessed pulsation, mortality, Symbiodiniaceae density, and cellular chlorophyll a content. Simulated ocean warming up to 30°C led to a significant increase in polyp pulsation and by the end of the experiment to a significant increase in Symbiodiniaceae density, whereas cellular chlorophyll a content significantly decreased with warming, regardless of the phosphate treatment. The combination of phosphate enrichment and simulated ocean warming increased pulsation significantly by 41 – 44%. Warming alone and phosphate enrichment alone did not affect any of the investigated response parameters. Overall, X. umbellata displayed a high resilience towards ocean warming with no mortality in all treatments. Phosphate enrichment enabled soft corals to significantly increase their pulsation under increasing temperatures which may enhance their resilience towards ocean warming. This, in turn, could further facilitate their dominance over hard corals on future reefs.

Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging: Diagnostic Pathways and Metabolites for Renal Tumor Entities

Background: Correct tumor subtyping of primary renal tumors is essential for treatment decision in daily routine. Most of the tumors can be classified based on morphology alone. Nevertheless, some diagnoses are difficult, and further investigations are needed for correct tumor subtyping. Besides histochemical investigations, high-mass-resolution matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) can detect new diagnostic biomarkers and hence improve the diagnostic. Patients and Methods: Formalin-fixed paraffin embedded tissue specimens from clear cell renal cell carcinoma (ccRCC, n = 552), papillary renal cell carcinoma (pRCC, n = 122), chromophobe renal cell carcinoma (chRCC, n = 108), and renal oncocytoma (rO, n = 71) were analyzed by high-mass-resolution MALDI fourier-transform ion cyclotron resonance (FT-ICR) MSI. The SPACiAL pipeline was executed for automated co-registration of histological and molecular features. Pathway enrichment and pathway topology analysis were performed to determine significant differences between RCC subtypes. Results: We discriminated the four histological subtypes (ccRCC, pRCC, chRCC, and rO) and established the subtype-specific pathways and metabolic profiles. rO showed an enrichment of pentose phosphate, taurine and hypotaurine, glycerophospholipid, amino sugar and nucleotide sugar, fructose and mannose, glycine, serine, and threonine pathways. ChRCC is defined by enriched pathways including the amino sugar and nucleotide sugar, fructose and mannose, glycerophospholipid, taurine and hypotaurine, glycine, serine, and threonine pathways. Pyrimidine, amino sugar and nucleotide sugar, glycerophospholipids, and glutathione pathways are enriched in ccRCC. Furthermore, we detected enriched phosphatidylinositol and glycerophospholipid pathways in pRCC. Conclusion: In summary, we performed a classification system with a mean accuracy in tumor discrimination of 85.13%. Furthermore, we detected tumor-specific biomarkers for the four most common primary renal tumors by MALDI-MSI. This method is a useful tool in differential diagnosis and biomarker detection.