18 research outputs found

    Temporal force governs the microbial assembly associated with Ulva fasciata (Chlorophyta) from an integrated multi-trophic aquaculture system

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    Ulva spp., one of the most important providers of marine ecosystem services, has gained substantial attention lately in both ecological and applicational aspects. It is known that macroalgae and their associated microbial community form an inseparable unit whose intimate relationship can affect the wellbeing of both. Different cultivation systems, such as integrated multi-trophic aquaculture (IMTA), are assumed to impact Ulva bacterial community significantly in terms of compositional guilds. However, in such a highly dynamic environment, it is crucial to determine how the community dynamics change over time. In the current study, we characterized the microbiota associated with Ulva fasciata grown as a biofilter in an IMTA system in the Gulf of Aqaba (Eilat, Israel) over a developmental period of 5 weeks. The Ulva-associated microbial community was identified using the 16S rRNA gene amplicon sequencing technique, and ecological indices were further analyzed. The Ulva-associated microbiome revealed a swift change in composition along the temporal succession, with clusters of distinct communities for each timepoint. Proteobacteria, Bacteroidetes, Planctomycetes, and Deinococcus-Thermus, the most abundant phyla that accounted for up to 95% of all the amplicon sequence variants (ASVs) found, appeared in all weeks. Further analyses highlighted microbial biomarkers representing each timepoint and their characteristics. Finally, the presence of highly abundant species in Ulva microbiota yet underestimated in previous research (such as phyla Deinococcus-Thermus, families Saprospiraceae, Thiohalorhabdaceae, and Pirellulaceae) suggests that more attention should be paid to the temporal succession of the assembly of microbes inhabiting macroalgae in aquaculture, in general, and IMTA, in particular. Characterizing bacterial communities associated with Ulva fasciata from an IMTA system provided a better understanding of their associated microbial dynamics and revealed this macroalgae's adaptation to such a habitat

    Development of Polyculture and Integrated Multi -Trophic Aquaculture (IMTA) in Israel: A Review

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    Israeli aquaculture began in the 1920s, with common carp monoculture. This was followed by polyculture of carp with tilapias, grey mullet, and planktivorous carp. Scientific research on polyculture started in the 1950s and has since contributed to the global science and practice of green water aquaculture, especially with novel polyculture approaches and concepts. Today, the industry is characterized by intensive freshwater polyculture, implemented in earthen fish ponds and reservoirs. In the Mediterranean coastal plain, fresh, brackish, and marine water polyculture is carried out in semi-intensive fishponds. Polyculture in Israel is an entrepreneurial activity that combines ecological principles of Chinese polyculture with local technologies and objectives. The Biofloc approach (active suspension ponds, ASP), periphyton, and aquaponics, were developed in the 1980s in response to rising public and policymakers’ concerns and regulations on land use, pollution, use of chemicals, and organic manures. R&D on marine integrated multi-trophic aquaculture (IMTA) systems began in the early 1970s at the National Center for Mariculture (NCM) in Eilat. It started with sea bream and mullet in earthen seawater ponds, whose plankton-rich water recirculated through bivalve and macroalgae biofiltration modules. An advanced form of the concept was deployed in the early 1980s and was studied in detail using nutrient budgets. Several system models with fish, bivalves, and algae, on small and pilot scales, were studied and quantified. Abalone, sea urchins, shrimp, brine shrimp, Salicornia, and periphyton, were added to the Eilat marine IMTA models, beginning in the 1990s. Upon entering the third millennium, Israeli research further examined the relationship between the sustainability and economics of IMTA in world aquaculture

    Data_Sheet_1_Temporal force governs the microbial assembly associated with Ulva fasciata (Chlorophyta) from an integrated multi-trophic aquaculture system.docx

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    Ulva spp., one of the most important providers of marine ecosystem services, has gained substantial attention lately in both ecological and applicational aspects. It is known that macroalgae and their associated microbial community form an inseparable unit whose intimate relationship can affect the wellbeing of both. Different cultivation systems, such as integrated multi-trophic aquaculture (IMTA), are assumed to impact Ulva bacterial community significantly in terms of compositional guilds. However, in such a highly dynamic environment, it is crucial to determine how the community dynamics change over time. In the current study, we characterized the microbiota associated with Ulva fasciata grown as a biofilter in an IMTA system in the Gulf of Aqaba (Eilat, Israel) over a developmental period of 5 weeks. The Ulva-associated microbial community was identified using the 16S rRNA gene amplicon sequencing technique, and ecological indices were further analyzed. The Ulva-associated microbiome revealed a swift change in composition along the temporal succession, with clusters of distinct communities for each timepoint. Proteobacteria, Bacteroidetes, Planctomycetes, and Deinococcus-Thermus, the most abundant phyla that accounted for up to 95% of all the amplicon sequence variants (ASVs) found, appeared in all weeks. Further analyses highlighted microbial biomarkers representing each timepoint and their characteristics. Finally, the presence of highly abundant species in Ulva microbiota yet underestimated in previous research (such as phyla Deinococcus-Thermus, families Saprospiraceae, Thiohalorhabdaceae, and Pirellulaceae) suggests that more attention should be paid to the temporal succession of the assembly of microbes inhabiting macroalgae in aquaculture, in general, and IMTA, in particular. Characterizing bacterial communities associated with Ulva fasciata from an IMTA system provided a better understanding of their associated microbial dynamics and revealed this macroalgae's adaptation to such a habitat.</p

    Context-Specific and Immune Cell-Dependent Antitumor Activities of α1-Antitrypsin

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    α1-antitrypsin (AAT), a circulating glycoprotein that rises during acute phase responses and healthy pregnancies, exhibits immunomodulatory properties in several T-cell–dependent immune pathologies. However, AAT does not interfere with isolated T-cell responses; instead, it facilitates polarization of macrophages and dendritic cells towards M2-like and tolerogenic cells, respectively. AAT also allows NK cell responses against tumor cells, while attenuating DC-dependent NK cell activities. Since AAT-treated macrophages bear resemblance to cancer-promoting tumor-associated macrophages (TAMs), it became imperative to examine the possible induction of tumor permissive conditions by AAT. Here, AAT treatment is examined for its effect on tumor development, metastatic spread and selected aspects of tumor immunology. Systemic AAT treatment of mice inoculated with B16-F10 melanoma cells resulted in significant inhibition of tumor growth and metastatic spread. Using NK cell–resistant RMA cells, we show that AAT interferes with tumor development in a CD8+ T-cell–dependent manner. Unexpectedly, upon analysis of tumor cellular composition we identified overly active tumor-infiltrating CD8+ T-cells alongside M1-like TAMs in AAT-treated mice. Based on the ability of AAT to undergo chemical modifications, we emulated conditions of elevated reactive nitrogen and oxygen species. Indeed, macrophages were stimulated by treatment with nitrosylated AAT, and IFN transcripts were significantly elevated in tumors extracted soon after ischemia-reperfusion challenge. These context-specific changes may explain the differential effects of AAT on immune responses towards tumor cells versus benign antigenic targets. These data suggest that systemically elevated levels of AAT may accommodate its physiological function in inflammatory resolution, without compromising tumor-targeting immune responses

    Point Mutation of a Non-Elastase-Binding Site in Human α1-Antitrypsin Alters Its Anti-Inflammatory Properties

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    IntroductionHuman α1-antitrypsin (hAAT) is a 394-amino acid long anti-inflammatory, neutrophil elastase inhibitor, which binds elastase via a sequence-specific molecular protrusion (reactive center loop, RCL; positions 357–366). hAAT formulations that lack protease inhibition were shown to maintain their anti-inflammatory activities, suggesting that some attributes of the molecule may reside in extra-RCL segments. Here, we compare the protease-inhibitory and anti-inflammatory profiles of an extra-RCL mutation (cys232pro) and two intra-RCL mutations (pro357cys, pro357ala), to naïve [wild-type (WT)] recombinant hAAT, in vitro, and in vivo.MethodsHis-tag recombinant point-mutated hAAT constructs were expressed in HEK-293F cells. Purified proteins were evaluated for elastase inhibition, and their anti-inflammatory activities were assessed using several cell-types: RAW264.7 cells, mouse bone marrow-derived macrophages, and primary peritoneal macrophages. The pharmacokinetics of the recombinant variants and their effect on LPS-induced peritonitis were determined in vivo.ResultsCompared to WT and to RCL-mutated hAAT variants, cys232pro exhibited superior anti-inflammatory activities, as well as a longer circulating half-life, despite all three mutated forms of hAAT lacking anti-elastase activity. TNFα expression and its proteolytic membranal shedding were differently affected by the variants; specifically, cys232pro and pro357cys altered supernatant and serum TNFα dynamics without suppressing transcription or shedding.ConclusionOur data suggest that the anti-inflammatory profile of hAAT extends beyond direct RCL regions. Such regions might be relevant for the elaboration of hAAT formulations, as well as hAAT-based drugs, with enhanced anti-inflammatory attributes

    Isolation of Bacteria Capable of Growth with 2-Methylisoborneol and Geosmin as the Sole Carbon and Energy Sources

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    Using a relatively simple enrichment technique, geosmin and 2-methylisoborneol (MIB)-biodegrading bacteria were isolated from a digestion basin in an aquaculture unit. Comparison of 16S rRNA gene sequences affiliated one of the three isolates with the Gram-positive genus Rhodococcus, while the other two isolates were found to be closely related to the Gram-negative family Comamonadaceae (Variovorax and Comamonas). Growth rates and geosmin and MIB removal rates by the isolates were determined under aerated and nonaerated conditions in mineral medium containing either of the two compounds as the sole carbon and energy source. All isolates exhibited their fastest growth under aerobic conditions, with generation times ranging from 3.1 to 5.7 h, compared to generation times of up to 19.1 h in the nonaerated flasks. Incubation of the isolates with additional carbon sources caused a significant increase in their growth rates, while removal rates of geosmin and MIB were significantly lower than those for incubation with only geosmin or MIB. By fluorescence in situ hybridization, members of the genera Rhodococcus and Comamonas were detected in geosmin- and MIB-enriched sludge from the digestion basin
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