Interspecies Communication Research Articles

Uncovering potential interspecies signaling factors in plant-derived mixed microbial culture

Microbes use signaling factors for intraspecies and interspecies communications. While many intraspecies signaling factors have been found and characterized, discovery of factors for interspecies communication is lagging behind. To facilitate the discovery of such factors, we explored the potential of a mixed microbial culture (MMC) derived from wheatgrass, in which heterogeneity of this microbial community might elicit signaling factors for interspecies communication. The stability of Wheatgrass MMC in terms of community structure and metabolic output was first characterized by 16S ribosomal RNA amplicon sequencing and liquid chromatography/mass spectrometry (LC/MS), respectively. In addition, detailed MS analyses led to the identification of 12-hydroxystearic acid (12-HSA) as one of the major metabolites produced by Wheatgrass MMC. Stereochemical analysis revealed that Wheatgrass MMC produces mostly the (R)-isomer, although a small amount of the (S)-isomer was also observed. Furthermore, 12-HSA was found to modulate planktonic growth and biofilm formation of various marine bacterial strains. The current study suggests that naturally derived MMCs could serve as a simple and reproducible platform to discover potential signaling factors for interspecies communication. In addition, the study indicates that hydroxylated long-chain fatty acids, such as 12-HSA, may constitute a new class of interspecies signaling factors.

Growing emergence of drug-resistant Pseudomonas aeruginosa and attenuation of its virulence using quorum sensing inhibitors: A critical review.

A perilous increase in the number of bacterial infections has led to developing throngs of antibiotics for increasing the quality and expectancy of life. Pseudomonas aeruginosa is becoming resistant to all known conventional antimicrobial agents thereby posing a deadly threat to the human population. Nowadays, targeting virulence traits of infectious agents is an alternative approach to antimicrobials that is gaining much popularity to fight antimicrobial resistance. Quorum sensing (QS) involves interspecies communication via a chemical signaling pathway. Under this mechanism, cells work in a concerted manner, communicate with each other with the help of signaling molecules called auto-inducers (AI). The virulence of these strains is driven by genes, whose expression is regulated by AI, which in turn acts as transcriptional activators. Moreover, the problem of antibiotic-resistance in case of infections caused by P. aeruginosa becomes more alarming among immune-compromised patients, where the infectious agents easily take over the cellular machinery of the host while hidden in the QS mediated biofilms. Inhibition of the QS circuit of P. aeruginosa by targeting various signaling pathways such as LasR, RhlR, Pqs, and QScR transcriptional proteins will help in blocking downstream signal transducers which could result in reducing the bacterial virulence. The anti-virulence agent does not pose an immediate selective pressure on growing bacterium and thus reduces the pathogenicity without harming the target species. Here, we review exclusively, the growing emergence of multi-drug resistant (MDR) P. aeruginosa and the critical literature survey of QS inhibitors with their potential application of blocking P. aeruginosa infections.

Joint effects of carbon nanotubes and copper oxide nanoparticles on fermentation metabolism towards Saccharofermentans acetigenes: Enhancing environmental adaptability and transcriptional expression

In this study, the joint effects of widely used copper oxide nanoparticles (CuO NPs) and multi-walled carbon nanotubes (MWCNTs) on the fermentation metabolism of a model acetogenic bacterium Saccharofermentans acetigenes were investigated and the underlying mechanisms were further explored. The presence of sole CuO NPs or MWCNTs severely inhibited the acetate generation, while their co-existences did not further decrease the acetate yield as expected. Further analysis indicated the joint effects facilitated the enhancement of bacterial stimulus response to the environment and interspecies communication, which improved adaptive capacity to the adverse environment involved in nanomaterials. Meanwhile, the co-existence reduced inhibitory effects of sole nanomaterial on the gene expressions and catalytic activities of key enzymes involved in glycolysis and pyruvate metabolism. Therefore, the joint effects could enhance environmental adaptation of S. acetigenes and transcriptional expressions of key enzymes for acetic acid production-related processes, alleviating the inhibition of CuO NPs to acetate production.

Bodies Underwater

Abstract This article engages with French filmmaker Jean Painlevé’s experimental shorts on the physiognomy and behavior of marine animals. The article argues that Painlevé’s films establish a corporeal and nonlinguistic mode of interspecies communication that draws upon the spectators’ immediate emphatic and empathetic reactions to the animal creatures on-screen. By evoking affective responses below the visible and audible registers, the films place the human animal body both in proximity to and at a distance from the nonhuman animal, revealing ontological ties as well as uncanny encounters with other ways of living. In doing so, the films inspire a plurality of ethico-political perspectives on species entanglement that all propose distinct responsibilities without making any organism the center of agentic events. To illuminate those perspectives, the article brings Painlevé’s films into conversation with Massumi’s animal politics, Deleuze and Guattari’s idea of becoming-animal, and neuroscientific research. It thus shows how the cinematic medium can make palpable debates in environmental studies and political theory and installs communication as an interspecies phenomenon that involves human and nonhuman bodies in a shared affective space. Last, the article reclaims Painlevé for contemporary concerns, linking aesthetics to ethics and politics and bodily movement to care for the world.

Histological and Immunohistochemical Characterization of Vomeronasal Organ Aging in Mice.

Simple SummaryChemical communication has been intensely studied and the importance of its role in animal life has been ascertained. Located in the nasal cavity, the vomeronasal organ is one of the main actors in charge of chemical reception. Alterations of this organ have proven to modify behavioral responses to semiochemical expositions. For all the other organs, a well-known origin of alteration is aging. The objective of this study was to analyze this effect on the vomeronasal organ condition and to determine the nature of these potential changes. This study demonstrates that this organ is significantly impacted by aging. In particular, old mice present strong signs of neuronal degeneration compared to adults.The vomeronasal organ (VNO) plays a crucial role in animal behavior since it is responsible for semiochemical detection and, thus, for intra- and interspecific chemical communication, through the vomeronasal sensory epithelium (VNSE), composed of bipolar sensory neurons. This study aimed to explore a well-recognized cause of neuronal degeneration, only rarely explored in this organ: aging. Murine VNOs were evaluated according to 3 age groups (3, 10, and 24 months) by histology to assess VNSE changes such as cellular degeneration or glycogen accumulation and by immunohistochemistry to explore nervous configuration, proliferation capability, and apoptosis with the expression of olfactory marker protein (OMP), Gαi2, Gαo, Ki-67, and cleaved caspase-3 proteins. These markers were quantified as percentages of positive signal in the VNSE and statistical analyses were performed. Cellular degeneration increased with age (p < 0.0001) as well as glycogen accumulation (p < 0.0001), Gαo expression (p < 0.0001), and the number of cleaved-caspase3 positive cells (p = 0.0425), while OMP and Gαi2 expressions decreased with age (p = 0.0436 and p < 0.0001, respectively). Ki67-positive cells were reduced, even if this difference was not statistically significant (p = 0.9105). Due to the crucial role of VNO in animal life, this study opens the door to interesting perspectives about chemical communication efficiency in aging animals.

Modulation of Arabidopsis thaliana growth by volatile substances emitted by Pseudomonas and Serratia strains.

Many volatile compounds secreted by bacteria play an important role in the interactions of microorganisms, can inhibit the growth of phytopathogenic bacteria and fungi, can suppress or stimulate plant growth and serve as infochemicals presenting a new type of interspecies communication. In this work, we investigated the effect of total pools of volatile substances and individual volatile organic compounds (VOCs) synthesized by the rhizosphere bacteria Pseudomonas chlororaphis 449 and Serratia plymuthica IC1270, the soil-borne strain P. fluorescens B-4117 and the spoiled meat isolate S. proteamaculans 94 on Arabidopsis thaliana plants. We showed that total gas mixtures secreted by these strains during their growth on Luria-Bertani agar inhibited A. thaliana growth. Hydrogen cyanide synthesis was unnecessary for the growth suppression. A decrease in the inhibition level was observed for the strain P. chlororaphis 449 with a mutation in the gacS gene, while inactivation of the rpoS gene had no effect. Individual VOCs synthesized by these bacteria (1-indecene, ketones 2-nonanone, 2-heptanone, 2-undecanone, and dimethyl disulfide) inhibited the growth of plants or killed them. Older A. thaliana seedlings were more resistant to VOCs than younger seedlings. The results indicated that the ability of some volatiles emitted by the rhizosphere and soil bacteria to inhibit plant growth should be considered when assessing the potential of such bacteria for the biocontrol of plant diseases.

Approaching Nonhuman Ontologies: Trees, Communication, and Qualitative Inquiry

Consideration of trees has historically been confined to disciplinary, quantitative perspectives embedded in botany, earth sciences, resource management, environmental sustainability, and sustainable development wherein trees are largely viewed as senseless, bio-mechanical matter to be controlled and used for human consumption and economic gain. In this article, I reflect selectively on methodologies and methods I used in a broader, interdisciplinary project to study the sentient, intelligent relationality of trees as agentic, conscious, innovative entities embedded in unique, community-based lifeways. My research framework integrated Indigenous research methodologies, public ethnography, ontological emergence theory, plant science, philosophies of plant and nonhuman knowing, interspecies communication, and filmmaking. Herein, I focus on how perspectives and approaches based on qualitative, ethnographic inquiry and Indigenous epistemologies support and broaden research, (re)presentation, and engagement with trees and other nonhumans. Methods I discuss include the practices of cultivating tree/human communication and fostering human sensitivity and embodied knowing.

Saccharomyces cerevisiae Requires CFF1 To Produce 4-Hydroxy-5-Methylfuran-3(2H)-One, a Mimic of the Bacterial Quorum-Sensing Autoinducer AI-2.

Quorum sensing is a process of cell-to-cell communication that bacteria use to orchestrate collective behaviors. Quorum sensing depends on the production, release, and detection of extracellular signal molecules called autoinducers (AIs) that accumulate with increasing cell density. While most AIs are species specific, the AI called AI-2 is produced and detected by diverse bacterial species, and it mediates interspecies communication. We recently reported that mammalian cells produce an AI-2 mimic that can be detected by bacteria through the AI-2 receptor LuxP, potentially expanding the role of the AI-2 system to interdomain communication. Here, we describe a second molecule capable of interdomain signaling through LuxP, 4-hydroxy-5-methylfuran-3(2H)-one (MHF), that is produced by the yeast Saccharomyces cerevisiae Screening the S. cerevisiae deletion collection revealed Cff1p, a protein with no known role, to be required for MHF production. Cff1p is proposed to be an enzyme, with structural similarity to sugar isomerases and epimerases, and substitution at the putative catalytic residue eliminated MHF production in S. cerevisiae Sequence analysis uncovered Cff1p homologs in many species, primarily bacterial and fungal, but also viral, archaeal, and higher eukaryotic. Cff1p homologs from organisms from all domains can complement a cff1ΔS. cerevisiae mutant and restore MHF production. In all cases tested, the identified catalytic residue is conserved and required for MHF to be produced. These findings increase the scope of possibilities for interdomain interactions via AI-2 and AI-2 mimics, highlighting the breadth of molecules and organisms that could participate in quorum sensing.IMPORTANCE Quorum sensing is a cell-to-cell communication process that bacteria use to monitor local population density. Quorum sensing relies on extracellular signal molecules called autoinducers (AIs). One AI called AI-2 is broadly made by bacteria and used for interspecies communication. Here, we describe a eukaryotic AI-2 mimic, 4-hydroxy-5-methylfuran-3(2H)-one, (MHF), that is made by the yeast Saccharomyces cerevisiae, and we identify the Cff1p protein as essential for MHF production. Hundreds of viral, archaeal, bacterial, and eukaryotic organisms possess Cff1p homologs. This finding, combined with our results showing that homologs from all domains can replace S. cerevisiae Cff1p, suggests that like AI-2, MHF is widely produced. Our results expand the breadth of organisms that may participate in quorum-sensing-mediated interactions.

A Biosemiotic and Ecoacoustic History of Bird-Scaring

Timo Maran has defined “biosemiotic criticism” as the study of human culture with an emphasis on the recognition that all forms of life are organized by sign processes. That approach guides this investigation of the sonic devices and practices that have been used in encounters between birds and humans in agricultural spaces. “Bird-scaring” has been a long-standing component of the semiotic relationship between humans and birds in what I am calling the agricultural semiosphere. The struggle between humans and “pest” species over the control of agricultural resources has spurred technological development, and an examination of the sonic tools that have been involved in bird-scaring practices, from wooden rattles to digital sound recordings, intersects with scholarship on sound technology and media studies. The field of ecoacoustics provides a conceptual framework for the sonic dynamics of the interspecies communication under examination. To the extent that the essay also explores the sign relations between humans and birds it has a place in the growing corpus of biosemiotic criticism. The historical account of bird-scaring practices is presented in three sections, demarcated by changes in technology as well as shifts in the mode of semiotic reference. Across the analysis, a historical approach to bird-scaring is interwoven with a discussion of biosemiotic and ecoacoustic themes and concepts.

Interspecies bacterial communication produces a delicate balance between Vibrio cholerae and the chironomid egg mass microbiome.

The evolution of antimicrobial resistance in bacterial pathogens is considered by the World Health Organization to be one of the ten most concerning public health threats facing humanity (World Health Organization, 2020). Bacterial diseases previously controllable by antibiotics are resurging and treatment options are dwindling. Cholera is one such disease. Human pathogenic strains of Vibrio cholerae cause as many as 4 million cases of disease resulting in over 100,000 deaths each year (Ali et al. 2015) and multidrug-resistant V. cholerae is now established where pandemic cholera persists. Vibrio cholerae is fundamentally an aquatic species thriving in brackish and estuarial waters. Its environmental prevalence, together with both extracellular and intracellular infection of alternative arthropod and mollusc hosts, produces a highly complex ecological milieu that is not well understood. With the absence of reliable antibiotic-based treatment options, it is necessary to build a better understanding of V. cholerae biology and ecology in order to develop alternative methods for risk modelling and disease control. In this issue of Molecular Ecology, authors Sela, Hammer, and Halpern experimentally investigated a mechanism by which V. cholerae pathogenicity is affected by interspecies quorum sensing involving an array of bacterial species from the microbiome of an alternative arthropod host, the egg mass of a chironomid midge (Diptera:Chironomidae) (Sela et al. 2020). Quorum sensing is a mechanism whereby bacteria communicate with each other using autoinducers and is known to be important, for example, in shaping virulence in a variety of pathogenic bacteria. The innovative methodologies they used, both in molecular and protein biology and reductive investigative microbiomics, are helping to develop the tools needed for understanding this understudied ecological system and fighting cholera in a post-antibiotic world.

Panax ginseng-Derived Extracellular Vesicles Facilitate Anti-Senescence Effects in Human Skin Cells: An Eco-Friendly and Sustainable Way to Use Ginseng Substances.

Ginseng is a traditional herbal medicine in eastern Asian countries. Most active constituents in ginseng are prepared via fermentation or organic acid pretreatment. Extracellular vesicles (EVs) are released by most organisms from prokaryotes to eukaryotes and play central roles in intra- and inter-species communications. Plants produce EVs upon exposure to microbes; however, their direct functions and utility for human health are barely known, except for being proposed as delivery vehicles. In this study, we isolated EVs from ginseng roots (GrEVs) or the culture supernatants of ginseng cells (GcEVs) derived from Panax ginseng C.A. Meyer and investigated their biological effects on human skin cells. GrEV or GcEV treatments improved the replicative senescent or senescence-associated pigmented phenotypes of human dermal fibroblasts or ultraviolet B radiation-treated human melanocytes, respectively, by downregulating senescence-associated molecules and/or melanogenesis-related proteins. Based on comprehensive lipidomic analysis using liquid chromatography mass spectrometry, the lipidomic profile of GrEVs differed from that of the parental root extracts, showing significant increases in 70 of 188 identified lipid species and prominent increases in diacylglycerols, some phospholipids (phosphatidylcholine, phosphatidylethanolamine, lysophosphatidylcholine), and sphingomyelin, revealing their unique vesicular properties. Therefore, our results imply that GEVs represent a novel type of bioactive and sustainable nanomaterials that can be applied to human tissues for improving tissue conditions and targeted delivery of active constituents.

Preliminary evidence of fluorescence in Mediterranean heterobranchs

ABSTRACTBiofluorescence, the ability to exploit light with short wavelengths, such as ultraviolet (UV) and blue, and re-emit it with lower energy and longer wavelengths, is considered a widespread phenomenon among marine animals and has many ecological roles in intra- and interspecific communication. Heterobranch sea slugs are believed to rely almost exclusively on their colour patterns for survival, with coloration serving as camouflage or as a warning to predators of heterobranch toxicity (aposematic coloration). Since solar light is progressively absorbed by seawater with a constant loss of longer wavelengths, it is unclear how heterobranch coloration can maintain its ecological role below the water surface. The present study investigates, for the first time, in situ biofluorescence in 53 species of Mediterranean Heterobranchia to determine whether these animals rely on light emission to enhance the visibility of their colour patterns. The ability to fluoresce when illuminated by UV and blue light (wavelengths &amp;lt;470 nm) appeared to be quite widespread among nudibranchs (i.e. found in c. one-third of the encountered species), while no evidence of light emission was found in non-nudibranch heterobranchs. The majority of fluorescent species were Cladobranchia belonging to the superfamilies Fionoidea and Aeolidioidea. Nudibranchs fluoresced in four different colours, with green being the most common. Light emission was often restricted to particular body regions, such as the cerata of Cladobranchia. These preliminary data might indicate that fluorescence plays an essential role in the enhancement of nudibranch aposematic coloration.

Legionella spp. All Ears? The Broad Occurrence of Quorum Sensing Elements outside Legionella pneumophila.

Legionella spp. are ubiquitous bacteria principally found in water networks and ∼20 species are implicated in Legionnaire’s disease. Among them, Legionella pneumophila is an intracellular pathogen of environmental protozoa, responsible for ∼90% of cases in the world. Legionella pneumophila regulates in part its virulence by a quorum sensing system named “Legionella quorum sensing,” composed of a signal synthase LqsA, two histidine kinase membrane receptors LqsS and LqsT and a cytoplasmic receptor LqsR. To date, this communication system was only found in L. pneumophila. Here, we investigated 58 Legionella genomes to determine the presence of a lqs cluster or homologous receptors using TBlastN. This analysis revealed three categories of species: 19 harbored a complete lqs cluster, 20 did not possess lqsA but maintained the receptor lqsR and/or lqsS, and 19 did not have any of the lqs genes. No correlation was observed between pathogenicity and the presence of a quorum sensing system. We determined by RT-qPCR that the lqsA gene was expressed at least in four strains among different species available in our laboratory. Furthermore, we showed that the lqs genomic region was conserved even in species possessing only the receptors of the quorum sensing system, indicating an ancestral acquisition and various loss dynamics during evolution. This system could therefore function in interspecific communication as well.

Fungal G-Protein-Coupled Receptors: A Promising Mediator of the Impact of Extracellular Signals on Biosynthesis of Ochratoxin A.

G-protein-coupled receptors (GPCRs) are transmembrane receptors involved in transducing signals from the external environment inside the cell, which enables fungi to coordinate cell transport, metabolism, and growth to promote their survival, reproduction, and virulence. There are 14 classes of GPCRs in fungi involved in sensing various ligands. In this paper, the synthesis of mycotoxins that are GPCR-mediated is discussed with respect to ligands, environmental stimuli, and intra-/interspecific communication. Despite their apparent importance in fungal biology, very little is known about the role of ochratoxin A (OTA) biosynthesis by Aspergillus ochraceus and the ligands that are involved. Fortunately, increasing evidence shows that the GPCR that involves the AF/ST (sterigmatocystin) pathway in fungi belongs to the same genus. Therefore, we speculate that GPCRs play an important role in a variety of environmental signals and downstream pathways in OTA biosynthesis. The verification of this inference will result in a more controllable GPCR target for control of fungal contamination in the future.

Transport pathways of hydrocarbon and free fatty acids to the cuticle in arthropods and hypothetical models in spiders.

Cuticular lipids in terrestrial arthropods are not only essential for desiccation resistance; they also play an important role as chemical signals for intra- and interspecific communication (pheromones and kairomones, respectively). Most of the studies on cuticular lipid research was dedicated to one class of arthropods, the insects. This type of research on the class arachnids is poorly developed, and the majority of studies has listed the compounds present in cuticular extracts, and, in some cases, compared the lipid profiles of different life stages (juveniles, adults). Consequently, we reviewed in relation to lipids description, biosynthesis, and transport of spiders. To illustrate a novel concept of lipid transportation, a scheme is now presented to show the hypothetical transport pathways of hydrocarbon and free fatty acids to cuticle in spiders. These concepts are taken from the knowledge of different arachnids to obtain a general illustration on the biosynthesis and transport of hemolymphatic lipids to the cuticle in spider.

Homo Sapiens, Mnesitardigrada Class and Umwelt: A Dialogue on Interspecies Organic Data Flow

This article presents artistic research based on existing knowledge about interspecific communication and hypothesis about the spread of interplanetary civilizations. It is expressed as an imagined communication flow between a human earthling scientist and a Kquaanian–human hybrid who is an artist by earthly occupation. While these two species’ sensoria are too different to allow discussion, this consideration supports the poetic approach to interspecies understanding, through immersive interactive installations and a willingness to share thoughts and feelings, in answering questions about the world and our place in it. The organs, molecules and protein expression of tardigrades provide a point of departure.

We Are One: Multispecies Metabolism of a Biofilm Consortium and Their Treatment Strategies.

The ecological and medical significance of bacterial biofilms have been well recognized. Biofilms are harder to control than their planktonic free-living counterparts and quite recently, the focus of the study has shifted to the multispecies consortia, which represent the vast majority of real-case infection scenarios. Studies have begun to explore the complex interspecies interactions within these biofilms. However, only little attention is currently given to the role of cellular metabolites in the cell-to-cell communication. The concentration gradients of metabolic substrates and products affect the spatial growth of bacteria in multispecies biofilm. This, if looked into more deeply, can lead to identification of potential therapies targeting the specific metabolites and hence the coordinated protection in the bacterial community. Herein, we review the interspecies communications, including their metabolic cross-talking, in multispecies biofilm, to signify the importance of such interactions on the initial formation and subsequent growth of these biofilms. Multispecies biofilms with their species heterogeneity are more resilient to antimicrobial agents than their single species biofilm counterparts and this characteristic is of particular interest when dealing with pathogenic bacteria. In this Review, we also discuss the treatment options available, to include current and emerging avenues to combat pathogenic multispecies biofilms in the clinical, environmental, as well as industrial settings.

Chemoreceptor Diversity in Apoid Wasps and Its Reduction during the Evolution of the Pollen-Collecting Lifestyle of Bees (Hymenoptera: Apoidea)

Chemoreceptors help insects to interact with their environment, to detect and assess food sources and oviposition sites, and to aid in intra- and interspecific communication. In Hymenoptera, species of eusocial lineages possess large chemoreceptor gene repertoires compared with solitary species, possibly because of their additional need to recognize nest-mates and caste. However, a critical piece of information missing so far has been the size of chemoreceptor gene repertoires of solitary apoid wasps. Apoid wasps are a paraphyletic group of almost exclusively solitary Hymenoptera phylogenetically positioned between ant and bee, both of which include eusocial species. We report the chemosensory-related gene repertoire sizes of three apoid wasps: Ampulex compressa, Cerceris arenaria, and Psenulus fuscipennis. We annotated genes encoding odorant (ORs), gustatory, and ionotropic receptors and chemosensory soluble proteins and odorant-binding proteins in transcriptomes of chemosensory tissues of the above three species and in early draft genomes of two species, A. compressa and C. arenaria. Our analyses revealed that apoid wasps possess larger OR repertoires than any bee lineage, that the last common ancestor of Apoidea possessed a considerably larger OR repertoire (∼160) than previously estimated (73), and that the expansion of OR genes in eusocial bees was less extensive than previously assumed. Intriguingly, the evolution of pollen-collecting behavior in the stem lineage of bees was associated with a notable loss of OR gene diversity. Thus, our results support the view that herbivorous Hymenoptera tend to possess smaller OR repertoires than carnivorous, parasitoid, or kleptoparasitic species.

Multiple ant colony optimization using both novel LSTM network and adaptive Tanimoto communication strategy

Ant Colony Optimization (ACO) tends to fall into local optima and has insufficient convergence when solving the Traveling Salesman Problem (TSP). To overcome this problem, this paper proposes a multiple ant colony optimization (LDTACO) based on novel Long Short-Term Memory network and adaptive Tanimoto communication strategy. Firstly, we introduce an Artificial Bee Colony-based Ant Colony System (ABC-ACS), which along with the classic Ant Colony System (ACS) and Max-Min Ant System (MMAS), form the final proposed algorithm. These three types of subpopulations complement each other to improve overall optimization performance. Secondly, the evaluation reward mechanism is proposed to enhance the guiding role of the Recommended paths, which can effectively accelerate convergence speed. Besides, an adaptive Tanimoto communication strategy is put forward for interspecific communication. When the algorithm is stagnant, the homogenized information communication method is activated to help the algorithm jump out of the local optima, thus improving solution accuracy. Finally, the experimental results show that the proposed algorithm can lead to more accurate solution accuracy and faster convergence speed.

Effect of calcinated pyrite on simultaneous ammonia, nitrate and phosphorus removal in the BAF system and the Fe2+ regulatory mechanisms: Electron transfer and biofilm properties

To efficiently remove nitrogen and phosphorus from secondary effluent with low values of COD/TN, a novel biological aerated filter (BAF) utilizing calcined pyrite with a large specific surface area (SSA) and pore diameter (PD) was designed to address this challenge. From the perspective of nutrients removal performance, and the corresponding effluent total nitrogen (TN) and PO43--P in the calcined pyrite autotrophic denitrification (CPAD) process decreased from 40.21 to 1.07 mg/L to 1.22 and 0.14 mg/L, respectively. Furthermore, the nutrients removal kinetics analysis showed that the CPAD and pyrite autotrophic denitrification (PAD) processes could be fitted with Half-order and Zero-order reactions via kinetics analysis, respectively, indicating that the TN removal performance of CPAD processes was better than that of the PAD process. Moreover, CPAD combined with sulfur autotrophic denitrification (SAD) processes was fitted by First-order reaction, and the TN removal performance was further enhanced over the CPAD process. From the perspective of microregulation, Fe2+ production in the PAD and CPAD processes could accelerate the electron transfer rate by increasing electron transport system activity (ETSA) and reducing electrochemical impedance spectroscopy (EIS). Moreover, Fe2+ stimulated microbes to produce more proteins (PN) and C10-HSL, which improved biofilm stability and interspecific communication processes. Notably, nitrifiers and autotrophic denitrifiers were simultaneously enriched via detection of high-throughput sequencing of 16 S rRNA genes, which verified the feasibility of simultaneous nitrification and autotrophic denitrification. Therefore, BAF with calcined pyrite and sulfur as composite fillers have a considerable advantage in nutrients removal.