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Harmful algal blooms, in particular recurrent blooms of the dinoflagellate Alexandrium catenella, associated with paralytic shellfish poisoning (PSP), frequently limit commercial shellfish harvests, resulting in serious socio-economic consequences. Although the PSP-inducing species that threaten the most vulnerable commercial species of shellfish are very patchy and spatially heterogeneous in their distribution, the spatial and temporal scales of their effects have largely been ignored in monitoring programs and by researchers. In this study, we examined the spatial and temporal dynamics of PSP toxicity in the clam (Ameghinomya antiqua) in two fishing grounds in southern Chile (Ovalada Island and Low Bay). During the summer of 2009, both were affected by an intense toxic bloom of A. catenella (up to 1.1 × 106 cells L−1). Generalized linear models were used to assess the potential influence of different environmental variables on the field detoxification rates of PSP toxins over a period of 12 months. This was achieved using a four parameter exponential decay model to fit and compare field detoxification rates per sampling site. The results show differences in the spatial variability and temporal dynamics of PSP toxicity, given that greater toxicities (+10-fold) and faster detoxification (20% faster) are observed at the Ovalada Island site, the less oceanic zone, and where higher amounts of clam are annually produced. Our observations support the relevance of considering different spatial and temporal scales to obtain more accurate assessments of PSP accumulation and detoxification dynamics and to improve the efficacy of fisheries management after toxic events.

The blooms of Alexandrium catenella, the main producer of paralytic shellfish toxins worldwide, have become the main threat to coastal activities in Southern Chile, such as artisanal fisheries, aquaculture and public health. Here, we explore retrospective data from an intense Paralytic Shellfish Poisoning outbreak in Southern Chile in Summer–Autumn 2016, identifying environmental drivers, spatiotemporal dynamics, and detoxification rates of the main filter-feeder shellfish resources during an intense A. catenella bloom, which led to the greatest socio-economic impacts in that area. Exponential detoxification models evidenced large differences in detoxification dynamics between the three filter-feeder species surf clam (Ensis macha), giant barnacle (Austromegabalanus psittacus), and red sea squirt (Pyura chilensis). Surf clam showed an initial toxicity (9054 µg STX-eq·100 g−1) around 10-fold higher than the other two species. It exhibited a relatively fast detoxification rate and approached the human safety limit of 80 µg STX-eq·100 g−1 towards the end of the 150 days. Ecological implications and future trends are also discussed. Based on the cell density evolution, data previously gathered on the area, and the biology of this species, we propose that the bloom originated in the coastal area, spreading offshore thanks to the resting cysts formed and transported in the water column.

Competition between microbes is extremely common, with many investing in mechanisms to harm other strains and species. Yet positive interactions between species have also been documented. What makes species help or harm each other is currently unclear. Here, we studied the interactions between 4 bacterial species capable of degrading metal working fluids (MWF), an industrial coolant and lubricant, which contains growth substrates as well as toxic biocides. We were surprised to find only positive or neutral interactions between the 4 species. Using mathematical modeling and further experiments, we show that positive interactions in this community were likely due to the toxicity of MWF, whereby each species’ detoxification benefited the others by facilitating their survival, such that they could grow and degrade MWF better when together. The addition of nutrients, the reduction of toxicity, or the addition of more species instead resulted in competitive behavior. Our work provides support to the stress gradient hypothesis by showing how harsh, toxic environments can strongly favor facilitation between microbial species and mask underlying competitive interactions.

Tropospheric ozone (O 3 ) is a secondary pollutant that causes oxidative stress in plants due to the generation of excess reactive oxygen species (ROS). Phenylpropanoid metabolism is induced as a usual response to stress in plants, and induction of key enzyme activities and accumulation of secondary metabolites occur, upon O 3 exposure to provide resistance or tolerance. The phenylpropanoid, isoprenoid, and alkaloid pathways are the major secondary metabolic pathways from which plant defense metabolites emerge. Chronic exposure to O 3 significantly accelerates the direction of carbon flows toward secondary metabolic pathways, resulting in a resource shift in favor of the synthesis of secondary products. Furthermore, since different cellular compartments have different levels of ROS sensitivity and metabolite sets, intracellular compartmentation of secondary antioxidative metabolites may play a role in O 3 -induced ROS detoxification. Plants’ responses to resource partitioning often result in a trade-off between growth and defense under O 3 stress. These metabolic adjustments help the plants to cope with the stress as well as for achieving new homeostasis. In this review, we discuss secondary metabolic pathways in response to O 3 in plant species including crops, trees, and medicinal plants; and how the presence of this stressor affects their role as ROS scavengers and structural defense. Furthermore, we discussed how O 3 affects key physiological traits in plants, foliar chemistry, and volatile emission, which affects plant–plant competition (allelopathy), and plant–insect interactions, along with an emphasis on soil dynamics, which affect the composition of soil communities via changing root exudation, litter decomposition, and other related processes.

In this study, a facile, ecological and economical green method is described for the fabrication of iron (Fe), copper (Cu) and silver (Ag) nanoparticles (NPs) from the extract of Syzygium cumini leaves. The obtained metal NPs were categorized using UV/Vis, SEM, TEM, FTIR and EDX-ray spectroscopy techniques. The Fe-, Cu- and Ag-NPs were crystalline, spherical and size ranged from 40-52, 28-35 and 11-19 nm, respectively. The Ag-NPs showed excellent antimicrobial activities against methicillin- and vancomycin-resistance Staphylococcus aureus bacterial strains and Aspergillus flavus and A. parasiticus fungal species. Furthermore, the aflatoxins (AFs) production was also significantly inhibited when compared with the Fe- and Cu-NPs. In contrast, the adsorption results of NPs with aflatoxin B1 (AFB1) were observed as following order Fe->Cu->Ag-NPs. The Langmuir isotherm model well described the equilibrium data by the sorption capacity of Fe-NPs (105.3 ng mg-1), Cu-NPs (88.5 ng mg-1) and Ag-NPs (81.7 ng mg-1). The adsorption was found feasible, endothermic and follow the pseudo-second order kinetic model as revealed by the thermodynamic and kinetic studies. The present findings suggests that the green synthesis of metal NPs is a simple, sustainable, non-toxic, economical and energy-effective as compared to the others conventional approaches. In addition, synthesized metal NPs might be a promising AFs adsorbent for the detoxification of AFB1 in human and animal food/feed.

Major environmental and genetic factors determining stress-related protein abundance are discussed.Major aspects of protein biological function including protein isoforms and PTMs, cellular localization and protein interactions are discussed.Functional diversity of protein isoforms and PTMs is discussed. Abiotic stresses reveal profound impacts on plant proteomes including alterations in protein relative abundance, cellular localization, post-transcriptional and post-translational modifications (PTMs), protein interactions with other protein partners, and, finally, protein biological functions. The main aim of the present review is to discuss the major factors determining stress-related protein accumulation and their final biological functions. A dynamics of stress response including stress acclimation to altered ambient conditions and recovery after the stress treatment is discussed. The results of proteomic studies aimed at a comparison of stress response in plant genotypes differing in stress adaptability reveal constitutively enhanced levels of several stress-related proteins (protective proteins, chaperones, ROS scavenging- and detoxification-related enzymes) in the tolerant genotypes with respect to the susceptible ones. Tolerant genotypes can efficiently adjust energy metabolism to enhanced needs during stress acclimation. Stress tolerance vs. stress susceptibility are relative terms which can reflect different stress-coping strategies depending on the given stress treatment. The role of differential protein isoforms and PTMs with respect to their biological functions in different physiological constraints (cellular compartments and interacting partners) is discussed. The importance of protein functional studies following high-throughput proteome analyses is presented in a broader context of plant biology. In summary, the manuscript tries to provide an overview of the major factors which have to be considered when interpreting data from proteomic studies on stress-treated plants.

Pesticide exposure, heavy metal pollution, and biological stressors drive a worldwide, ongoing, and rapid population decline of the crucial pollinator honeybee. Drastic colony loss of honeybees may well precipitate a food security crisis. Here a systematic review was conducted, examining reports on a global scale to propose a bench line for common pesticides and potentially toxic element (PTE) residue levels in plant rewards and honeybees and to assess the health risk of chemical residues via oral exposure to honeybees. Relevant articles were retrieved from Scopus, PubMed, ISI Web of Science, and Embase. Recent findings on how chemical and biological stressors cripple honeybee health, and conservation techniques were also summarized. We identified a number of chemical residues at lethal or sublethal risk to honeybees based on their average concentrations, as well as primary evidence pertaining to the bio-accumulative propensity of certain substances. Moreover, combinations of pesticide stressors (“pesticide cocktails”), which are frequently encountered in agricultural landscapes, often interact synergistically with honeybee health via detoxification suppression. Finally, we discuss and describe the relevance of novel, biotechnology-based, approaches to counteract agrochemical and PTE poisoning.

Rhodanese, the primary cyanide-detoxifying enzyme, plays a crucial role in mitigating the harmful effects of cyanide present in various industrial waste materials, such as battery manufacturing effluents. The bioremediation of cyanide-contaminated environments relies on efficient detoxification mechanisms, making rhodanese a valuable enzyme for biotechnological applications. This research aimed to investigate the biochemical properties of purified rhodanese produced by Aspergillus welwitschiae LOT1, a fungal strain with promising cyanide detoxification capabilities. The purified rhodanese was obtained through fermentation, precipitation, and chromatographic separations, resulting in a homogeneous band of approximately 58 kDa with a specific activity of 374 RU/mg, 28-fold purification, and 14% recovery. The enzyme exhibited optimal cyanide detoxification at pH 7 and 60 °C, with stability observed between 30 and 50 °C and pH 8–10. All metal ions examined except for Cu 2+ enhanced the cyanide-degrading ability of rhodanese. Notably, the enzyme demonstrated a high substrate preference for Na 2 S 2 O 3 and followed a first-order kinetic model and free energy, ΔG of 61.3 kJ/mol, making it a promising candidate for biotechnological applications. Overall, this study provides valuable insights into the biochemical properties of rhodanese from A. welwitschiae LOT1, highlighting its potential for efficient cyanide detoxification and bioremediation.

Among numerous soil problems, metals or trace elements (TEs) accumulation is one of the significant agronomic tasks which have extremely threatened food safety. Due to these, soil agronomists in recent times have also raised concerns over metal pollution, which indeed are obnoxious, disturbing the agricultural ecosystems and agricultural crops. Because metals are not biodegradable, they can survive in the environment, enter the food chain via crop plants, and accumulate in the human body through bio- magnification. Once harmful metals have accumulated over specifically permitted thresholds, they negatively impact microbiota density, composition, physiological activity, soil dynamics, and fertility, leading ultimately to a decrease in wheat production via the food chain, human and animal health. Overall wheat growth and yield decrease with an increasing quantity of TES. So, land contamination must be remedied as soon as possible. Phytoremediation is an environmentally benign strategy that could be a cost-effective solution to revegetate trace metal-polluted soil. Certain microorganisms, particularly those belonging to the plant growth-promoting rhizobacteria (PGPR) group, have been identified as having the unique property of metal tolerance and exhibiting unique plant growth-promoting potentials in order to reduce the magnitude of metal-induced changes. By delivering macro and micronutrients and secreting active biomolecules such as extracellular polymorphic substances (EPS), melanin, and metallothionein (MTs), such metal-tolerant PGPR have shown varying favorable impacts on wheat productivity in soils even contaminated with TEs. In this review, we explore the mechanisms by which metals are taken up, and their effect on plant growth, translocation, and detoxification in plants. We concentrate on the ways used to improve phytostabilization and phytoextraction efficiencies, such as genetic engineering, microbe-assisted, and chelate-assisted procedures.

The postantibiotic effect (PAE) refers to the temporary suppression of bacterial growth following transient antibiotic treatment. This effect has been observed for decades for a wide variety of antibiotics and microbial species. However, despite empirical observations, a mechanistic understanding of this phenomenon is lacking. Using a combination of modeling and quantitative experiments, we show that the PAE can be explained by the temporal dynamics of drug detoxification in individual cells after an antibiotic is removed from the extracellular environment. These dynamics are dictated by both the export of the antibiotic and the intracellular titration of the antibiotic by its target. This mechanism is generally applicable for antibiotics with different modes of action. We further show that efflux inhibition is effective against certain antibiotic motifs, which may help explain mixed cotreatment success. Synopsis The postantibiotic effect (PAE) refers to the temporary inhibition of bacterial growth following transient antibiotic treatment. This study indicates an underlying mechanism for this phenomenon, based on minimal binding and efflux dynamics. The PAE is a widely observed phenomenon whereby bacterial populations transiently exhibit minimal growth after temporary antibiotic treatment. In this study, mathematical modeling and experimental studies demonstrate that PAE can be explained by drug binding and efflux dynamics, and that these processes are applicable to many diverse antibiotics. Modeling analyses show that the efficacy of efflux pump inhibitors, widely thought to be effective antibiotic adjuvants, is modulated by mechanism‐dependent dynamics. Graphical Abstract The postantibiotic effect (PAE) refers to the temporary inhibition of bacterial growth following transient antibiotic treatment. This study indicates an underlying mechanism for this phenomenon, based on minimal binding and efflux dynamics.