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The archaeal mevalonate pathway is a recently discovered modified version of the eukaryotic mevalonate pathway. This pathway is widely conserved in archaea, except for some archaeal lineages possessing the eukaryotic or other modified mevalonate pathways. Although the pathway seems almost exclusive to the domain Archaea, the whole set of homologous genes of the pathway is found in the metagenome-assembled genome sequence of an uncultivated bacterium, Candidatus Promineifilum breve, of the phylum Chloroflexota. To prove the existence of the archaea-specific pathway in the domain Bacteria, we confirmed the activities of the enzymes specific to the pathway, phosphomevalonate dehydratase and anhydromevalonate phosphate decarboxylase, because only these two enzymes are absent in closely related Chloroflexota bacteria that possess a different type of modified mevalonate pathway. The activity of anhydromevalonate phosphate decarboxylase was evaluated by carotenoid production via the archaeal mevalonate pathway reconstituted in Escherichia coli cells, whereas that of phosphomevalonate dehydratase was confirmed by an in vitro assay using the recombinant enzyme after purification and iron-sulfur cluster reconstruction. Phylogenetic analyses of some mevalonate pathway-related enzymes suggest an evolutionary route for the archaeal mevalonate pathway in Candidatus P. breve, which probably involves horizontal gene transfer events. [ABSTRACT FROM AUTHOR]

This study is the first to investigate the presence and movement of the novel Liberibacter species 'Candidatus Liberibacter brunswickensis' (CLbr) in eggplant, Solanum melongena. The psyllid, Acizzia solanicola can transmit CLbr to eggplant and CLbr can be acquired by CLbr-negative A. solanicola individuals from CLbr-positive eggplants. In planta, CLbr can replicate, move and persist. Investigation into the early development of eggplants showed that CLbr titres had increased at the inoculation site at 14 days post inoculation access period (DPIAP). CLbr had become systemic in the majority of plants tested by 28 DPIAP. The highest bacterial titres were recorded at 35 DPIAP in all samples of the inoculated leaf, the roots, stems and the midrib and petiole samples of the newest leaf (the top leaf). This finding strongly suggests that CLbr movement in planta follows the source to sink relationship as previously described for 'Ca. Liberibacter asiaticus' (CLas) and 'Ca. Liberibacter solanacearum' (CLso). No symptoms consistent with Liberibacter-associated diseases were noted for plants colonised by CLbr during this study, consistent with the hypothesis that CLbr does not cause disease of eggplant during the early stages of host colonisation. In addition, no significant differences in biomass were found between eggplant colonised with CLbr, compared to those that were exposed to CLbr-negative A. solanicola, and to control plants. [ABSTRACT FROM AUTHOR]

Phytoplasmic SAP11 effectors alter host plant architecture and flowering time. However, the exact mechanisms have yet to be elucidated. Two SAP11‐like effectors, SJP1 and SJP2, from 'Candidatus Phytoplasma ziziphi' induce shoot branching proliferation. Here, the transcription factor ZjTCP7 was identified as a central target of these two effectors to regulate floral transition and shoot branching. Ectopic expression of ZjTCP7 resulted in enhanced bolting and earlier flowering than did the control. Interaction and expression assays demonstrated that ZjTCP7 interacted with the ZjFT‐ZjFD module, thereby enhancing the ability of these genes to directly bind to the ZjAP1 promoter. The effectors SJP1 and SJP2 unravelled the florigen activation complex by specifically destabilising ZjTCP7 and ZjFD to delay floral initiation. Moreover, the shoot branching of the ZjTCP7‐SRDX transgenic Arabidopsis lines were comparable to those of the SJP1/2 lines, suggesting the involvement of ZjTCP7 in the regulation of shoot branching. ZjTCP7 interacted with the branching repressor ZjBRC1 to enhance suppression of the auxin efflux carrier ZjPIN3 expression. ZjTCP7 also directly bound to and upregulated the auxin biosynthesis gene ZjYUCCA2, thereby promoting auxin accumulation. Our findings confirm that ZjTCP7 serves as a bifunctional regulator destabilised by the effectors SJP1 and SJP2 to modulate plant development. Summary statement: Efectors SJP1 and SJP2 interact with and destabilise the bifunctional regulator ZjTCP7 to modulate flowering‐related ZjFT‐ZjFD pathway and branching signalling controlled by ZjBRC1 in jujube, suggesting a novel regulatory mechanism mediated by JWB phytoplasmas to modulate host plant development. [ABSTRACT FROM AUTHOR]

The high diversity and global distribution of heterotrophic bacterial diazotrophs (HBDs) in the ocean has recently become apparent. However, understanding the role these largely uncultured microorganisms play in marine N2 fixation poses a challenge due to their undefined growth requirements and the complex regulation of the nitrogenase enzyme. We isolated and characterized Candidatus Thalassolituus haligoni, a member of a widely distributed clade of HBD belonging to the Oceanospirillales. Analysis of its nifH gene via amplicon sequencing revealed the extensive distribution of Cand. T. haligoni across the Pacific, Atlantic, and Arctic Oceans. Pangenome analysis indicates that the isolate shares >99% identity with an uncultured metagenome-assembled genome called Arc-Gamma-03, recently recovered from the Arctic Ocean. Through combined genomic, proteomic, and physiological approaches, we confirmed that the isolate fixes N2 gas. However, the mechanisms governing nitrogenase regulation in Cand. T. haligoni remain unclear. We propose Cand. T. haligoni as a globally distributed, cultured HBD model species within this understudied clade of Oceanospirillales. [ABSTRACT FROM AUTHOR]

BACKGROUND: Citrus huanglongbing (HLB) is a devastating disease caused by Candidatus Liberibacter asiaticus (CLas) that affects the citrus industry. In nature, CLas relies primarily on Diaphorina citri Kuwayama as its vector for dissemination. After D. citri ingests CLas‐infected citrus, the pathogen infiltrates the insect's body, where it thrives, reproduces, and exerts regulatory control over the growth and metabolism of D. citri. Previous studies have shown that CLas alters the composition of proteins in the saliva of D. citri, but the functions of these proteins remain largely unknown. RESULTS: In this study, we detected two proteins (DcitSGP1 and DcitSGP3) with high expression levels in CLas‐infected D. citri. Quantitative PCR and Western blotting analysis showed that the two proteins were highly expressed in the salivary glands and delivered into the host plant during feeding. Silencing the two genes significantly decreased the survival rate for D. citri, reduced phloem nutrition sucking and promoted jasmonic acid (JA) defenses in citrus. By contrast, after overexpressing the two genes in citrus, the expression levels of JA pathway‐associated genes decreased. CONCLUSION: Our results suggest that CLas can indirectly suppress the defenses of citrus and support feeding by D. citri via increasing the levels of effectors in the insect's saliva. This discovery facilitates further research into the interaction between insect vectors and pathogens. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

A novel coupling process to replace the traditional multi-stage anammox process—sulfur autotrophic denitrification (SAD) coupled anaerobic ammonium oxidation (anammox) system was designed, which solved problems of nitrate produced in anammox process and low nitrate conversion rate caused by nitrite accumulation in SAD process. Different filter structures (SAD filter and anammox granular sludge) were investigated to further explore the excellent performance of the novel integrated reactor. The results of sequential batch experiments indicated that nitrite accumulation occurred during SAD, which inhibited the conversion of nitrate to dinitrogen gas. When SAD filter and anammox granular sludge were added to packed bed reactor simultaneously, the nitrate removal rate increased by 37.21% and effluent nitrite concentration decreased by 100% compared to that achieved using SAD. The stratified filter structure solved groove flow. Different proportion influence of SAD filter and anammox granular sludge on the stratified filter structure was evaluated. More suitable ratio of SAD filter to anammox granular sludge was 2:1. Proteobacteria (57.26%), Bacteroidetes (20.12%) and Chloroflexi (9.95%) were the main phyla. The dominant genera of denitrification functional bacteria were Thiobacillus (39.80%), Chlorobaculum (3.99%), norank_f_PHOs-HE36 (2.90%) and Ignavibacterium (2.64%). The dominant genus of anammox bacterium was Candidatus_Kuenenia (3.05%). [ABSTRACT FROM AUTHOR]

DPANN archaea are a diverse group of microorganisms characterised by small cells and reduced genomes. To date, all cultivated DPANN archaea are ectosymbionts that require direct cell contact with an archaeal host species for growth and survival. However, these interactions and their impact on the host species are poorly understood. Here, we show that a DPANN archaeon (Candidatus Nanohaloarchaeum antarcticus) engages in parasitic interactions with its host (Halorubrum lacusprofundi) that result in host cell lysis. During these interactions, the nanohaloarchaeon appears to enter, or be engulfed by, the host cell. Our results provide experimental evidence for a predatory-like lifestyle of an archaeon, suggesting that at least some DPANN archaea may have roles in controlling host populations and their ecology. DPANN archaea are a group of microorganisms that require direct cell contact with other archaeal host species for growth. Here, Hamm et al. show that a DPANN archaeon engages in parasitic interactions with its host leading to host cell lysis, thus providing experimental evidence of a predatory-like lifestyle for an archaeon. [ABSTRACT FROM AUTHOR]

Haemotrophic mycoplasmas (haemoplasmas) are a group of highly specific and adapted bacteria. Three different haemoplasma species in pigs are known to date: Mycoplasma (M.) suis, M. parvum and 'Candidatus (Ca.) M. haemosuis'. Even though these bacteria have been known in pig farming for a long time, it is difficult to draw general conclusions about the relevance of their infections in pigs. This review summarizes the current knowledge on the three porcine haemoplasma species with regards to clinical and pathological descriptions, pathobiology, epidemiology and diagnostics as well as prevention and therapy. Overall, it is clear that considerably more data are available for M. suis than for the other two species, but generally, porcine haemoplasmas were found to be highly prevalent all over the world. Mycoplasma suis is the most virulent species, causing acute infectious anaemia in pigs (IAP), whereas M. parvum usually results in chronic and subclinical infections associated with performance losses. Little is known about the clinical significance of the recently discovered third porcine species 'Ca. M. haemosuis'. So far, the described pathogenic mechanisms mainly include direct destruction of erythrocytes via adhesion, invasion, eryptosis and nutrient scavenging, indirect erythrocyte lysis due to immune-mediated events and immune dysregulation processes. A review of published diagnostic data confirms PCR assays as the current standard method, with various cross-species and species-specific protocols. Overall, there is a need for further examination to obtain valuable insights for practical application, specifically regarding the importance of subclinical infections in naturally infected animals. An essential requirement for this will be to gain a more comprehensive understanding of the mechanisms operating between the host and the pathogen. [ABSTRACT FROM AUTHOR]

Phytoplasmas manipulate host plant development to benefit insect vector colonization and their own invasion. However, the virulence factors and mechanisms underlying small-leaf formation caused by jujube witches' broom (JWB) phytoplasmas remain largely unknown. Here, effectors SJP1 and SJP2 from JWB phytoplasmas were identified to induce small-leaf formation in jujube (Ziziphus jujuba). In vivo interaction and expression assays showed that SJP1 and SJP2 interacted with and stabilized the transcription factor ZjTCP2. Overexpression of SJP1 and SJP2 in jujube induced ZjTCP2 accumulation. In addition, the abundance of miRNA319f_1 was significantly reduced in leaves of SJP1 and SJP2 transgenic jujube plants and showed the opposite pattern to the expression of its target, ZjTCP2 , which was consistent with the pattern in diseased leaves. Overexpression of ZjTCP2 in Arabidopsis promoted ectopic leaves arising from the adaxial side of cotyledons and reduced leaf size. Constitutive expression of the miRNA319f_1 precursor in the 35S::ZjTCP2 background reduced the abundance of ZjTCP2 mRNA and reversed the cotyledon and leaf defects in Arabidopsis. Therefore, these observations suggest that effectors SJP1 and SJP2 induced small-leaf formation, at least partly, by interacting with and activating ZjTCP2 expression both at the transcriptional and the protein level, providing new insights into small-leaf formation caused by phytoplasmas in woody plants. [ABSTRACT FROM AUTHOR]

Background: 'Candidatus Phytoplasma mali', the causal agent of apple proliferation disease, exerts influence on its host plant through various effector proteins, including SAP11CaPm which interacts with different TEOSINTE BRANCHED1/ CYCLOIDEA/ PROLIFERATING CELL FACTOR 1 and 2 (TCP) transcription factors. This study examines the transcriptional response of the plant upon early expression of SAP11CaPm. For that purpose, leaves of Nicotiana occidentalis H.-M. Wheeler were Agrobacterium-infiltrated to induce transient expression of SAP11CaPm and changes in the transcriptome were recorded until 5 days post infiltration. Results: The RNA-seq analysis revealed that presence of SAP11CaPm in leaves leads to downregulation of genes involved in defense response and related to photosynthetic processes, while expression of genes involved in energy production was enhanced. Conclusions: The results indicate that early SAP11CaPm expression might be important for the colonization of the host plant since phytoplasmas lack many metabolic genes and are thus dependent on metabolites from their host plant. [ABSTRACT FROM AUTHOR]

• CCBS, HEPES, and PBS were investigated for improving the performance of anammox sludge. • Anammox activity and reactor start-up speed were improved with CO 2 /NaHCO 3 buffer. • Dominant anammox bacteria was Candidatus Kuenenia with the relative abundance of 71.8%. • Reactors could be started and enriched with anammox bacteria within microaerobic conditions. Anammox bacteria grow slowly and can be affected by large pH fluctuations. Using suitable buffers could make the start-up of anammox reactors easy and rapid. In this study, the effects of three kinds of buffers on the nitrogen removal and growth characteristics of anammox sludge were investigated. Reactors with CO 2 /NaHCO 3 buffer solution (CCBS) performed the best in nitrogen removal, while 4-(2-hydroxyerhyl)piperazine-1-ethanesulfonic acid (HEPES) and phosphate buffer solution (PBS) inhibited the anammox activity. Reactors with 50 mmol/L CCBS could start up in 20 days, showing the specific anammox activity and anammox activity of 1.01±0.10 gN/(gVSS·day) and 0.83±0.06 kgN/(m3·day), respectively. Candidatus Kuenenia was the dominant anammox bacteria, with a relative abundance of 71.8%. Notably, anammox reactors could also start quickly by using 50 mmol/L CCBS under non-strict anaerobic conditions. These findings are meaningful for the quick start-up of engineered anammox reactors and prompt enrichment of anammox bacteria. [Display omitted] [ABSTRACT FROM AUTHOR]

Coriariaceae are a small plant family of 14–17 species and subspecies that currently have a global but disjunct distribution. All species can form root nodules in symbiosis with diazotrophic Frankia cluster-2 strains, which form the earliest divergent symbiotic clade within this bacterial genus. Studies on Frankia cluster-2 mostly have focused on strains occurring in the northern hemisphere. Except for one strain from Papua New Guinea, namely Candidatus Frankia meridionalis Cppng1, no complete genome of Frankia associated with Coriaria occurring in the southern hemisphere has been published thus far, yet the majority of the Coriariaceae species occur here. We present field sampling data of novel Frankia cluster-2 strains, representing two novel species, which are associated with Coriaria arborea and Coriaria sarmentosa in New Zealand, and with Coriaria ruscifolia in Patagonia (Argentina), in addition to identifying Ca. F. meridionalis present in New Zealand. The novel Frankia species were found to be closely related to both Ca. F. meridionalis, and a Frankia species occurring in the Philippines, Taiwan, and Japan. Our data suggest that the different Frankia cluster-2 species diverged early after becoming symbiotic circa 100 million years ago. [ABSTRACT FROM AUTHOR]

In surveys conducted from 2020 to 2022, five leaf samples each from symptomatic Agele marmelos trees and seedlings, along with five samples from asymptomatic trees and seedlings, were collected in Ayodhya, Uttar Pradesh, India. The DNA extraction from all the samples was subjected to nested PCR assays, using the universal phytoplasma-specific primers set (P1/P7 followed by R16F2n/R16R2). The resulting 1.2 kb amplified products were observed in all the symptomatic samples but not in the asymptomatic samples. Bael phytoplasma strain sequences from the trees and seedlings were found 100% identical within themselves and only two representative sequences (one each from tree and seedling) were deposited in GenBank (NCBI) as PP415872 (AmA-1) and PP415873 (AmA-2). BLASTn searches revealed the maximum (100%) sequence identity with a phytoplasma strain from murraya little leaf strain of Faizabad (GenBank Acc.no. OP984129) and lowest (99.84%) with arecanut crown choking of Shimoga (GenBank Acc. no. OM417502) from Karnataka. Phylogenetic analysis clustered the bael phytoplasma isolates with peanut witches' broom group phytoplasma strains. Virtual RFLP analysis confirmed their identity as 'Ca. P. australasiaticum', a 16SrII-D subgroup strain. This study presents the first identification of a phytoplasma strain in A. marmelos, emphasizing its potential threat to fruit crops and the need for vigilance in nursery practices to prevent further dissemination. [ABSTRACT FROM AUTHOR]

Infections with phytoplasma present one of the most significant biotic stresses influencing plant health, growth, and production. The phytoplasma 'Candidatus Phytoplasma solani' infects a variety of plant species. This pathogen impacts the physiological and morphological characteristics of plants causing stunting, yellowing, leaf curling, and other symptoms that can lead to significant economic losses. The aim of this study was to determine biochemical changes in peony (Paeonia tenuifolia L.), mint (Mentha × piperita L.), and dill (Anethum graveolens L.) induced by 'Ca. Phytoplasma solani' in Serbia as well as to predict the impact of the biotic stress using artificial neural network (ANN) modeling. The phylogenetic position of the Serbian 'Ca. Phytoplasma solani' strains originated from the tested hosts using 16S rRNA (peony and carrot strains) and plsC (mint and dill strains) sequences indicated by their genetic homogeneity despite the host of origin. Biochemical parameters significantly differed in asymptomatic and symptomatic plants, except for total anthocyanidins contents in dill and the capacity of peony and mint extracts to neutralize superoxide anions and hydroxyl radicals, respectively. Principal Component Analysis (PCA) showed a correlation between different chemical parameters and revealed a clear separation among the samples. Based on the ANN performance, the optimal number of hidden neurons for the calculation of TS, RG, PAL, LP, NBT, •OH, TP, TT, Tflav, Tpro, Tant, DPPH, and Car was nine (using MLP 8-9-13), as it produced high r2 values (1.000 during the training period) and low SOS values. Developing an effective early warning system for the detection of plant diseases in different plant species is critical for improving crop yield and quality. [ABSTRACT FROM AUTHOR]

Phytoplasmas are linked to diseases in hundreds of economically important crops, including carrots. In carrots, phytoplasmosis is associated with leaf chlorosis and necrosis, coupled with inhibited root system development, ultimately leading to significant economic losses. During a field study conducted in Baden-Württemberg (Germany), two strains of the provisional taxon 'Candidatus Phytoplasma asteris' were identified within a carrot plot. For further analysis, strains M8 and M33 underwent shotgun sequencing, utilising single-molecule-real-time (SMRT) long-read sequencing and sequencing-by-synthesis (SBS) paired-end short-read sequencing techniques. Hybrid assemblies resulted in complete de novo assemblies of two genomes harboring circular chromosomes and two plasmids. Analyses, including average nucleotide identity and sequence comparisons of established marker genes, confirmed the phylogenetic divergence of 'Ca. P. asteris' and a different assignment of strains to the 16S rRNA subgroup I-A for M33 and I-B for M8. These groups exhibited unique features, encompassing virulence factors and genes, associated with the mobilome. In contrast, pan-genome analysis revealed a highly conserved gene set related to metabolism across these strains. This analysis of the Aster Yellows (AY) group reaffirms the perception of phytoplasmas as bacteria that have undergone extensive genome reduction during their co-evolution with the host and an increase of genome size by mobilome. [ABSTRACT FROM AUTHOR]

The Candidate Phyla Radiation (CPR) encompasses widespread uncultivated bacteria with reduced genomes and limited metabolic capacities. Most CPR bacteria lack the minimal set of enzymes required for peptidoglycan (PG) synthesis, leaving it unclear how these bacteria produce this essential envelope component. In this study, we analysed the distribution of d‐amino acid racemases that produce the universal PG components d‐glutamate (d‐Glu) or d‐alanine (d‐Ala). We also examined moonlighting enzymes that synthesize d‐Glu or d‐Ala. Unlike other phyla in the domain Bacteria, CPR bacteria do not exhibit these moonlighting activities and have, at most, one gene encoding either a Glu or Ala racemase. One of these 'orphan' racemases is a predicted Glu racemase (MurICPR) from the CPR bacterium Candidatus Saccharimonas aalborgenesis. The expression of MurICPR restores the growth of a Salmonellad‐Glu auxotroph lacking its endogenous racemase and results in the substitution of l‐Ala by serine as the first residue in a fraction of the PG stem peptides. In vitro, MurICPR exclusively racemizes Glu as a substrate. Therefore, Ca. Saccharimonas aalborgensis may couple Glu racemization to serine and d‐Glu incorporation into the stem peptide. Our findings provide the first insights into the synthesis of PG by an uncultivated environmental bacterium and illustrate how to experimentally test enzymatic activities from CPR bacteria related to PG metabolism. [ABSTRACT FROM AUTHOR]

Phytophthora gummosis, foot rot, and root rot are considered major challenges to the citrus industry worldwide. Little is known about the Phytophthora–microbiome interaction, despite several studies demonstrating changes in the microbial composition of the rhizosphere following challenges by a pathogen. In the present study, we studied the microbial diversity and community structure in healthy rhizospheres and Phytophthora-infected rhizospheres of Khasi mandarin (Citrus reticulata Blanco), a commercial cultivar extensively grown in the northeast of India. An exploratory study was conducted to identify Phytophthora-infected orchards of Khasi mandarin, and the isolated pathogen was confirmed as P. nicotianae based on its morpho-cultural and molecular characteristics coupled with pathogenicity tests. This study on culturable microbes established the dominance of Trichoderma spp. in the healthy rhizosphere, while the diseased rhizosphere showed the presence of Fusarium spp. A metagenomic study further revealed that the rhizospheres of Phytophthora-infected plants were dominated by species such as Bacteroidia spp., Patescibacteria spp., and Pythium spp., while the healthy Khasi mandarin rhizospheres had a more diverse community predominantly represented by Trichoderma, Penicillium, Linnemannia, Mortierella, Talaromyces, Saitozyma, Bacteroidetes, Pseudomonas, Cytophagia, Cyanobacteria, Bacteroidia, Sphingobacteriia, Burkholderia, Bacillus, and Bradyrhizobium. Terrabacteria and FCB (Fibrobacterota, Chlorobiota, and Bacteroidota groups) were found to exist in higher relative abundance in disease-free soils than in Phytophthora-infected soils, while phylum Proteobacteria showed identical relative abundance in all soil types. The phyla represented by Pseudomonas, Flavobacteriia, Candidatus, Mycobacterium, Rhizobium, Mesorhizobium, Sphingomonas, and Cytophagia were the most common bacterial phyla in all soil samples, but healthy soil exhibited a greater abundance of Bacteroidetes, Pseudomonas, Cytophagia, Cyanobacteria, Bacteroidia, Sphingobacteriia, Burkholderia, Bacillus, and Bradyrhizobium. Our study suggests that the presence of Phytophthora spp. in the rhizosphere alters microbial community structure, having potentially strong implications for plant health and productivity. These rhizosphere microbiome-derived citrus responses shed light on exploring effective management strategies for Phytophthora gummosis disease ailing Khasi mandarin. [ABSTRACT FROM AUTHOR]

Ciliates are unicellular eukaryotes, regularly involved in symbiotic associations. Symbionts may colonize the inside of their cells as well as their surface as ectosymbionts. Here, we report on a new ciliate species, designated as Zoothamnium mariella sp. nov. (Peritrichia, Sessilida), discovered in the northern Adriatic Sea (Mediterranean Sea) in 2021. We found this ciliate species to be monospecifically associated with a new genus of ectosymbiotic bacteria, here proposed as Candidatus Fusimicrobium zoothamnicola gen. nov., sp. nov. To formally describe the new ciliate species, we investigated its morphology and sequenced its 18S rRNA gene. To demonstrate its association with a single species of bacterial ectosymbiont, we performed 16S rRNA gene sequencing, fluorescence in situ hybridization, and scanning electron microscopy. Additionally, we explored the two partners' cultivation requirements and ecology. Z. mariella sp. nov. was characterized by a colony length of up to 1 mm. A consistent number of either seven or eight long branches alternated on the stalk in close distance to each other. The colony developed three different types of zooids: microzooids ("trophic stage"), macrozooids ("telotroch stage"), and terminal zooids ("dividing stage"). Viewed from inside the cell, the microzooids' oral ciliature ran in 1 ¼ turns in a clockwise direction around the peristomial disc before entering the infundibulum, where it performed another ¾ turn. Phylogenetic analyses assigned Z. mariella sp. nov. to clade II of the family Zoothamnidae. The ectosymbiont formed a monophyletic clade within the Gammaproteobacteria along with two other ectosymbionts of peritrichous ciliates and a free-living vent bacterium. It colonized the entire surface of its ciliate host, except for the most basal stalk of large colonies, and exhibited a single, spindle-shaped morphotype. Furthermore, the two partners together appear to be generalists of temperate, oxic, marine shallow-water environments and were collectively cultivable in steady flow-through systems. [ABSTRACT FROM AUTHOR]

Simple Summary: The planthopper Pentastiridius leporinus is the main vector of two bacterial pathogens (Arsenophonus and stolbur phytoplasma) that cause a disease known as syndrome basses richesses (SBR) in sugar beet, reducing the yield and sugar content. In 2022, P. leporinus nymphs were also found to transmit Arsenophonus in potato fields, causing symptoms like wilting, yellow leaves, and rubbery tubers. We monitored both pathogens in Southwest Germany in 2022 and 2023, revealing that P. leporinus adults can transmit Arsenophonus and stolbur to potatoes. The broad prevalence of Arsenophonus was maintained, whereas the prevalence of stolbur increased in most regions in 2023. Neither of the pathogens influenced the germination rate of potato tubers, and no abnormal growth was observed after germination. Arsenophonus was not detected in germinated shoots, but stolbur was present, emphasizing the need for plant material testing to prevent outbreaks of disease. The planthopper Pentastiridius leporinus (Hempiptera: Cixiidae) is the main vector of two bacterial pathogens: the γ-proteobacterium 'Candidatus Arsenophonus phytopathogenicus' and the stolbur phytoplasma 'Candidatus Phytoplasma solani'. These pathogens cause the disease syndrome basses richesses (SBR) in sugar beet (Beta vulgaris), which reduces the yields and sugar content. In 2022, potato (Solanum tuberosum) fields were found to be colonized by P. leporinus, and the transmission of Arsenophonus was confirmed, resulting in symptoms like wilting, yellow leaves, and rubbery tubers. We monitored both pathogens in Southwest Germany in 2022 and 2023. This revealed their widespread presence in potato tubers, although there were differences in regional prevalence. The broad prevalence of Arsenophonus was maintained in 2023, whereas the prevalence of stolbur increased in most locations. We confirmed that P. leporinus adults can transmit both pathogens to potatoes, but neither pathogen reduced the germination rate of tubers, and no plants showed abnormal growth after germination. Arsenophonus was not detected in germinated shoots, but 5.4% contained stolbur, emphasizing the need for plant material testing to maintain phytosanitary conditions. [ABSTRACT FROM AUTHOR]

A new disease syndrome of zucchini squash was observed in Southern Italy, in 2018 and again in 2020. Affected plants were severely stunted and leaves were bent downwards, small, stiff, thick, leathery, and had interveinal chloroses. In addition, flowers were virescent and fruits were deformed and often cracked. Disease incidence was 20 and 30% in two different zucchini cultivations in Campania region (Southern Italy). Tomato yellow leaf curl New Delhi virus (ToLCNDV) was detected in eight samples, by loop-mediated isothermal amplification-based (LAMP) kit and by PCR and Sanger sequencing of the AV1 gene. Phytoplasmas were detected in the same samples using nested PCR assays with primer pairs P1/P7 and R16F2n/R16R2. Phytoplasma associations in plant samples were confirmed using specific primers for the multilocus genes SecY, tuf and rp. Sequence comparison of multilocus genes and phylogenetic analyses of the 16S rDNA gene confirmed the association of a phytoplasma strain closely related to 'Candidiatus Phytoplamsa asteris'. This is the first report of mixed infections of ToLCNDV and a putative 'Ca. Phytoplamsa asteris' strain in zucchini, associated with a new Squash-Phytoplasma-Begomovirus (SqPB) disease syndrome. [ABSTRACT FROM AUTHOR]

The hypersensitivity of anammox bacteria toward fluctuating temperature (seasonal) conditions significantly limits its real-world application. Biomass immobilization alleviates the impact of environmental shocks on the anammox process. In this study (291 d), a sequencing batch reactor engaging dishwashing scrubbers as model waste biocarriers and an amalgamation of activated, anaerobic, and anammox sludge (1:1:0.5 ratio) as inoculum (at influent pH 8.0) were deployed for the startup of the anammox process. Intriguingly, the SBR was run at ambient temperature (6–37 °C) at varying nitrogen loading rates (g N m−3 d−1) of 20, 30, 40, 46.4, 58, 60, 81.2, 92.8, and 116. Notably, anammox activation took place at ⁓247 d wherein the reactor performance improved and exhibited stable nitrogen removal (NH4+–N, NO2−–N and total nitrogen removals were 100, 99, and 72.04%, respectively). Additionally, post 279 days of reactor operation (280 – 291 d), the reactor demonstrated an average total nitrogen removal rate (g N m−3 d−1) of 88.2 at a maximum nitrogen loading rate (g N m−3 d−1) of 116. The 16S rRNA gene sequencing results revealed that Anammox bacteria predominated in the reactor, highlighting the fact that the reported increase in the percentage abundance of Candidatus Kuenenia at 266 d was exorbitantly higher (41.69%) than inoculum sludge (0.18%). Nitrospira (23.9%) and Nitrosomonas (4.32%), in addition to anammox, were found in high concentrations, suggesting presence of dissolved oxygen in the system. [ABSTRACT FROM AUTHOR]

Background: Hemotropic mycoplasmas or hemoplasmas are bacteria that attach to the erythrocyte surface and cause bovine hemoplasmosis. Two species, Mycoplasma wenyonii and Candidatus Mycoplasma haemobos, have been identified and shown to be distributed worldwide. However, there is currently no information available on hemoplasmas in cattle in the Republic of Korea. The aim of this study was to investigate the presence of hemoplasmas in Korean native cattle and to evaluate the association between hemoplasma infection and anemia. Methods: One farm was selected, at which blood samples were collected from 104 Korean native cattle [grazing cattle (n = 89) and housed cattle (n = 15)]. Hemoplasmas were detected via polymerase chain reaction analysis and complete blood counts were also performed. Results: The overall prevalence of hemoplasmas was 34% (35/104); 20.2% (21/104) for M. wenyonii, 3.8% (4/104) for C. M. haemobos, and 9.6% (10/104) for co-infection. Candidatus Mycoplasma haemobos was detected only in grazing cattle. Of red blood cell (RBC) parameters, C. M. haemobos-infected cattle had lower RBC and hematocrit, and higher mean cell volume than hemoplasma-negative cattle, although none of these differences were statistically significant. This is the first study to report the occurrence of M. wenyonii and C. M. haemobos. Mycoplasma wenyonii is more prevalent than C. M. haemobos in Korean native cattle. The results did not show an association between hemoplasma infection and anemia. Conclusions: Considering the infection rate of hemoplasmas shown in this study, further studies, such as on the pathogenicity and clinical significance of hemoplasmas are necessary. [ABSTRACT FROM AUTHOR]

Trachyspermum ammi is a traditional medicinal plant and is widely used for curing various diseases in humans. During a 2022 survey, yellowing symptoms associated with phytoplasma disease were observed in Bhopal. The disease was detected by direct and nested PCR using phytoplasma-specific primers in symptomatic plant leaf samples. The suspected ~ 1.2 kb amplified amplicons were sequenced and submitted in GenBank under accession number OQ216747. The phytoplasma isolate showed the highest 99.42% sequence identity and phylogenetic relationships with the 16 S ribosomal RNA gene of an isolate of aster yellows phytoplasma ('Candidatus Phytoplasma asteris'; 16SrI group). This is the first report of 'Ca. P. asteris' (16SrI) associated with the yellows disease of T. ammi. [ABSTRACT FROM AUTHOR]

The sandal spike disease (SSD), related to 'Ca. Phytoplasma asteris' (Aster Yellows group), poses a significant threat to Indian sandalwood (Santalum album L.), making it the second most expensive wood globally due to declining population density. The epidemiology of SSD and the nature of the pathogen remain poorly understood. The SW86 isolate, collected from the Marayoor Sandalwood Reserve, was chosen for genome sequencing subsequent to confirming its titer and enriching phytoplasma DNA. Genome sequencing, utilizing Illumina and Oxford Nanopore Technology platforms, enabled a targeted hybrid metagenomic assembly resulting in 20 scaffolds totaling 554,025 bp, housing 436 protein-coding genes, 27 tRNA, and 1 rRNA operon. The genome analysis highlighted specific gene distributions, emphasizing translation, ribosomal structure, and biogenesis, with 352 genes assigned to 18 functional categories. Additionally, 322 proteins received functional assignments in the KEGG database, emphasizing 'Genetic Information Processing' and 'Environmental Information Processing'. Key potential pathogenicity factors, including signal peptide proteins and virulence proteins, were identified. Noteworthy findings include homologs of effectors genes like SAP11 and SAP05 and pathogenesis-related proteins, such as hemolysin III and SodA genes, in the SW86 genome. The duplicated cation-transporting P-type ATPase in the SW86 genome suggests a role in enhancing adaptability and contributing to the severity of SSD symptoms. This genome analysis provides crucial insights into the genomic features and potential virulence factors of 'Ca. Phytoplasma asteris' strain SW86, advancing our understanding of pathogenicity mechanisms and offering avenues for future disease management strategies in Indian sandalwood. [ABSTRACT FROM AUTHOR]

Zinnia peruviana (Asteraceae) is an annual flowering plant cultivated in various gardens of Mysore, the south of Karnataka state, India. During 2021, phytoplasma‐like symptoms such as virescence and phyllody were observed on Zinnia in Mysore local gardens. A total of 10 symptomatic and five asymptomatic samples were collected, and the DNA was amplified by PCR using primers specific to 16S RNA and secA genes. The nucleotide sequence analysis showed that the 16S RNA and SecA gene sequences were most similar to those of 'Ca. P. aurantifolia', with identities greater than 99%. The phytoplasma sequence from this study shared a common clade with 'Ca. P. aurantifolia' when phylogenetic analysis was done. Similarly, the reference sequences for the 16S rRNA and SecA region confirmed the identity of the phytoplasma associated with the leaves of Zinnia. This is the new host record for 'Ca. P. aurantifolia' (16SrII‐D) phytoplasma associated with Z. peruviana from India. [ABSTRACT FROM AUTHOR]

Lack of information for wild plant hosts of Bactericera cockerelli limits understanding of ecology and phenology of the insect and actual role of wild host plants in disease dynamics. Because of vectoring the plant pathogenic bacterium Candidatus Liberibacter solanacearum (Lso), B. cockerelli is one of the most important pests of solanaceus crops. Herein, B. cockerelli is reported to be associated with a previously unrecognized wild plant host, Margaranthus solanaceus Schltdl. (netted globe-cherry) on lowland plains of northeastern Mexico. In total, 37 Margaranthus plant samples were collected at Cadereyta, State of Nuevo Leon, Mexico. From these, 761 eggs and 129 nymphs were obtained (mean of 20.56 ± 1.04 eggs and 3.48 ± 0.4 nymphs per plant). The insect completed its lifecycle on the plant. PCR indicated that three of 35 Margaranthus plants examined (8.6%) were positive for Lso infection; because of methodological difficulties, the percentage was probably underestimated. All adult psyllids (100%) in a sample (n = 21) that emerged from nymphs on Margaranthus and were analyzed by PCR were infected by Lso. This is the first report of M. solanaceous as host of B. cockerelli, Lso and Lso-infected B. cockerelli. With other wild hosts, the plant might contribute to population dynamics of B. cockerelli and Lso in North America. La falta de información sobre plantas hospedantes silvestres de Bactericera cockerelli ha limitado la comprensión de la ecología y fenología del insecto y el papel real de estas plantas en la dinámica de la enfermedad. Debido a la vectorización de la bacteria fitopatógena Candidatus Liberibacter solanacearum (Lso), B. cockerelli es una de las plagas más importantes de cultivos de solanáceas. En este documento, se reporta que B. cockerelli está asociada con una planta huésped silvestre no enlistada, Margaranthus solanaceus Schltdl., en las llanuras bajas del noreste de México. Se recolectaron un total de 37 muestras de plantas Margaranthus en Cadereyta, estado de Nuevo León, México. De éstas se obtuvieron 761 huevos y 129 ninfas (medias de 20.6 ± 1.04 huevos y 3.48 ± 0.4 ninfas por planta). El insecto completó su desarrollo hasta adulto en esta planta. La PCR indicó que tres de 35 plantas examinadas (8,6%) fueron positivas a la infección por Lso; debido a dificultades metodológicas, este porcentaje probablemente esté subestimado. Todos los psílidos adultos (100%) en una muestra (n = 21) que emergieron de Margaranthus y fueron analizados por PCR también fueron positivos a Lso. Este es el primer informe de M. solanaceous como huésped de B. cockerelli, de Lso y de B. cockerelli infectado con Lso. Junto con otros huéspedes silvestres, esta planta puede contribuir a la dinámica poblacional de B. cockerelli y Lso en América del Norte. [ABSTRACT FROM AUTHOR]

Simple Summary: In Germany, the planthopper Pentastiridius leporinus currently represents the most important vector for the spread of two pathogens, 'Candidatus Arsenophonus phytopathogenicus' and 'Candidatus Phytoplasma solani', which are associated with the syndrome "Basses Richesses" in sugar beets. In 2022, this planthopper was also found in potato fields in Germany along with symptoms of yellowing, wilting and rubbery tubers. In this study, greenhouse experiments with adult P. leporinus were conducted showing that it is able to transmit both pathogens to potatoes. Furthermore, it was confirmed that this vector can complete its entire lifecycle on both crops. To enable an accurate assessment of the phytoplasma titer in the vector and host plant, real-time PCR assays were performed using a synthetic DNA standard. Our study results highlight that P. leporinus may play an increasingly important role in agricultural cropping systems being a vector for two bacterial pathogens in two crops. In Germany, the phloem-sucking planthopper Pentastiridius leporinus (Hemiptera: Cixiidae) currently represents the epidemiological driver for the spread of the syndrome "Basses Richesses" in sugar beets, which results in a reduced sugar content and an economic loss for the farmers. This disease is associated with the γ-proteobacterium 'Candidatus Arsenophonus phytopathogenicus' and the Stolbur phytoplasma 'Candidatus Phytoplasma solani'. Recently, P. leporinus was found in potato fields in Germany and is associated with Stolbur-like symptoms in this crop. In this study, we confirmed that the vector completes its lifecycle on sugar beets as well as on potatoes when reared under controlled conditions. Transmission experiments with adults of this vector combined with molecular analyses showed, for the first time, that both pathogens are transmitted by this vector to potatoes. For an accurate assessment of the Ca. P. solani and Ca. A. phytopathogenicus titers in the vector and host plants, gBlocks derived from the hsp20- and 16S rRNA genes were employed, respectively. For Ca. P. solani, the limit of detection was determined in potato and sugar beet material. The results of this study will further the research on the epidemiology of the syndrome "Basses Richesses" and "Stolbur" diseases and the response of host plants and vector insects to both pathogens. [ABSTRACT FROM AUTHOR]

Simple Summary: Camel anaplasmosis is a recent emerging disease with potential zoonotic concerns. There is poor understanding of the epidemiology of anaplasmosis in camels and, in particular of Candidatus Anaplasma camelii, which is detected in several countries including Saudi Arabia, Iran, Kenya, and Morocco. Most studies of anaplasmosis in camels relied on microscopy and serology for diagnosis, and few used molecular approaches. The present work characterizes Anaplasmataceae strains circulating in the Camelus dromedarius reservoir in the United Arab Emirates (UAE) using PCR, sequencing, and phylogenetic analysis for the first time to provide information about the largely neglected disease they cause. Between 2019 to 2023, thirty-five whole-blood samples (35/287 = 12.2%) tested positive for Anaplasmataceae spp. by PCR assay targeting the groEL gene. Of these, only nine positive samples (9/35 = 25.7%) were sequenced using groEL gene primers. A GenBank BLAST analysis revealed that all strains were 100% identical to the Candidatus Anaplasma camelii reference sequence available in the GenBank nucleotide database. The recent emergence of anaplasmosis in camels has raised global interest in the pathogenicity and zoonotic potential of the pathogen causing it and the role of camels as reservoir hosts. In the United Arab Emirates (UAE), molecular studies and genetic characterization of camel-associated Anaplasma species are limited. This study aimed to characterize molecularly Anaplasmataceae strains circulating in dromedary camels in the UAE. Two hundred eighty-seven whole-blood samples collected from dromedary camels across regions of the Abu Dhabi Emirate were received between 2019 and 2023 at the Abu Dhabi Agriculture and Food Safety Authority (ADAFSA) veterinary laboratories for routine diagnosis of anaplasmosis. The animals were sampled based on field clinical observation by veterinarians and their tentative suspicion of blood parasite infection on the basis of similar clinical symptoms as those caused by blood parasites in ruminants. The samples were screened for Anaplasmataceae by PCR assay targeting the groEL gene. Anaplasmataceae strains were further characterized by sequencing and phylogenetic analysis of the groEL gene. Thirty-five samples (35/287 = 12.2%) tested positive for Anaplasmataceae spp. by PCR assay. Nine positive samples (9/35 = 25.7%) were sequenced using groEL gene primers. GenBank BLAST analysis revealed that all strains were 100% identical to the Candidatus A. camelii reference sequence available in the GenBank nucleotide database. Phylogenetic analysis further indicated that the sequences were close to each other and were located in one cluster with Candidatus A. camelii sequences detected in Saudi Arabia, Morocco, and the UAE. Pairwise alignment showed that the UAE sequences detected in this study were completely identical and shared 100% identity with Candidatus A. camelii from Morocco and Saudi Arabia and 99.5% identity with Candidatus A. camelii from the UAE. This study demonstrates the presence of Candidatus A. camelii in UAE dromedary camels. Further critical investigation of the clinical and economical significance of this pathogen in camels needs to be carried out. [ABSTRACT FROM AUTHOR]

Introduction: Candidatus Liberibacter solanacearum (CLso) is a regulated plant pathogen in European and some Asian countries, associated with severe diseases in economically important Apiaceous and Solanaceous crops, including potato, tomato, and carrot. Eleven haplotypes of CLso have been identified based on the difference in rRNA and conserved genes and host and pathogenicity. Although it is pathogenic to a wide range of plants, the mechanisms of plant response and functional decline of host plants are not well defined. This study aims to describe the underlying mechanism of the functional decline of tomato plants infected by CLso by analyzing the transcriptomic response of tomato plants to CLso haplotypes A and B. Methods: Next-generation sequencing (NGS) data were generated from total RNA of tomato plants infected by CLso haplotypes A and B, and uninfected tomato plants, while qPCR analysis was used to validate the in-silico expression analysis. Gene Ontology and KEGG pathways were enriched using differentially expressed genes. Results: Plants infected with CLso haplotype B saw 229 genes upregulated when compared to uninfected plants, while 1,135 were downregulated. Healthy tomato plants and plants infected by haplotype A had similar expression levels, which is consistent with the fact that CLso haplotype A does not show apparent symptoms in tomato plants. Photosynthesis and starch biosynthesis were impaired while starch amylolysis was promoted in plants infected by CLso haplotype B compared with uninfected plants. The changes in pathway gene expression suggest that carbohydrate consumption in infected plants was more extensive than accumulation. In addition, cell-wall-related genes, including steroid biosynthesis pathways, were downregulated in plants infected with CLso haplotype B suggesting a reduction in membrane fluidity, cell signaling, and defense against bacteria. In addition, genes in phenylpropanoid metabolism and DNA replication were generally suppressed by CLso infection, affecting plant growth and defense. Discussion: This study provides insights into plants' defense and functional decline due to pathogenic CLso using whole transcriptome sequencing and qPCR validation. Our results show how tomato plants react in metabolic pathways during the deterioration caused by pathogenic CLso. Understanding the underlying mechanisms can enhance disease control and create opportunities for breeding resistant or tolerant varieties. [ABSTRACT FROM AUTHOR]

Apple proliferation (AP) is an economically important disease in many apple-growing regions caused by 'Candidatus Phytoplasma mali' which is spread by migrating psyllid vectors on a regional scale. As infected trees in orchards are the only inoculum source, the early eradication of those trees is one of the most efficient strategies to prevent further spread of AP. Remote sensing is a promising rapid and cost-effective tool to identify infected trees on a regional scale. AP-induced premature leaf reddening was evaluated as a reliable symptom for remote sensing by monitoring more than 20,000 trees in 68 different orchards with 20 representative cultivars from 2019 to 2022 in a highly AP-affected region in Southwest Germany. Specific AP symptoms were almost 100% correlated with molecular detection of 'Ca. P. mali' and these specific symptoms were almost 100% correlated with leaf reddening. 'Ca. P. mali' was detected in 71–97% of trees which showed partial or entire reddening without any other AP symptom. Experimental and field data showed that reddening was induced by cold night and warm day temperatures (about 5 °C vs. 20 °C) in September. Quantification of the phytoplasma by real-time PCR showed no correlation with the intensity of reddening in the leaf. PCR-RFLP subtyping revealed no influence of different 'Ca. P. mali' strains on the symptom expression. In conclusion, leaf reddening in late September/early October was a reliable symptom useful for remote sensing of AP. [ABSTRACT FROM AUTHOR]

Ticks are important vectors of zoonotic diseases and play a major role in the circulation and transmission of many rickettsial species. The aim of this study was to investigate the carriage of Candidatus Rickettsia tarasevichiae (CRT) in a total of 1168 ticks collected in Inner Mongolia to elucidate the potential public health risk of this pathogen, provide a basis for infectious disease prevention, control and prediction and contribute diagnostic ideas for clinical diseases that present with fever in populations exposed to ticks. A total of four tick species, Haemaphysalis concinna (n = 21), Dermacentor nuttalli (n = 122), Hyalomma marginatum (n = 148), and Ixodes persulcatus (n = 877), were collected at nine sampling sites in Inner Mongolia, China, and identified by morphological and molecular biological methods. Reverse transcription PCR targeting the 16S ribosomal RNA (rrs), gltA, groEL, ompB and Sca4 genes was used to detect CRT DNA. Sequencing was used for pathogen species confirmation. The molecular epidemiological analysis showed that three species of ticks were infected with CRT, and the overall positive rate was as high as 42%. The positive rate of I. persulcatus collected in Hinggan League city was up to 96%, and that of I. persulcatus collected in Hulun Buir city was 50%. The pool positive rates of D. nuttalli and H. marginatum collected in Bayan Nur city and H. concinna collected in Hulun Buir city were 0%, 28% and 40%, respectively. This study revealed the high prevalence of CRT infection in ticks from Inner Mongolia and the first confirmation of CRT detected in H. marginatum in China. The wide host range and high infection rate in Inner Mongolia may dramatically increase the exposure of CRT to humans and other vertebrates. The role of H. marginatum in the transmission of rickettsiosis and its potential risk to public health should be further considered. [ABSTRACT FROM AUTHOR]

As belonging to one of the most isolated continents on our planet, the microbial composition of different environments in Antarctica could hold a plethora of undiscovered species with the potential for biotechnological applications. This manuscript delineates our discoveries after an expedition to the Bulgarian Antarctic Base "St. Kliment Ohridski" situated on Livingston Island, Antarctica. Amplicon-based metagenomics targeting the 16S rRNA genes and ITS2 region were employed to assess the metagenomes of the bacterial, fungal, and archaeal communities across diverse sites within and proximal to the research station. The predominant bacterial assemblages identified included Oxyphotobacteria, Bacteroidia, Gammaprotobacteria, and Alphaprotobacteria. A substantial proportion of cyanobacteria reads were attributed to a singular uncultured taxon within the family Leptolyngbyaceae. The bacterial profile of a lagoon near the base exhibited indications of penguin activity, characterized by a higher abundance of Clostridia, similar to lithotelm samples from Hannah Pt. Although most fungal reads in the samples could not be identified at the species level, noteworthy genera, namely Betamyces and Tetracladium, were identified. Archaeal abundance was negligible, with prevalent groups including Woesearchaeales, Nitrosarchaeum, Candidatus Nitrosopumilus, and Marine Group II. [ABSTRACT FROM AUTHOR]

The unicellular cyanobacterium Candidatus Atelocyanobacterium thalassa (UCYN‐A) is a key diazotroph in the global ocean owing to its high N2 fixation rates and wide distribution in marine environments. Nevertheless, little is known about UCYN‐A in oxygen‐deficient zones (ODZs), which may be optimal environments for marine diazotrophy. Therefore, the distribution and diversity of UCYN‐A were studied in two consecutive years under contrasting phases (La Niña vs. El Niño) of El Niño Southern Oscillation (ENSO) along a transect in the ODZ of the Mexican Pacific upwelling system. Of the three UCYN‐A sublineages found, UCYN‐A1 and UCYN‐A3 were barely detected, whereas UCYN‐A2 was dominant in all the stations and showed a wide distribution in both ENSO phases. The presence of UCYN‐A was associated with well‐oxygenated waters, but it was also found for the first time under suboxic conditions (<20 μM) at the bottom of a shallow coastal station, within the oxygen‐poor and nutrient‐rich Subsurface Subtropical water mass. This study contributes to the understanding of UCYN‐A distribution under different oceanographic conditions associated with ENSO phases in upwelling systems, especially because of the current climate change and increasing deoxygenation in many areas of the world's oceans. [ABSTRACT FROM AUTHOR]

Simple Summary: Psyllids are insects that represent a potential threat to the cultivation of several crops, mainly as vectors of the 'Candidatus Liberibacter' bacteria species. Surveys on the presence and abundance of insect vectors of pathogens can provide important information on the presence of related pathogens in a certain area, even before the appearance of disease symptoms in plants. The occurrence of psyllid vectors was investigated on carrot crops in the "Altopiano del Fucino" area (Abruzzo region), where the highest Italian carrot production occurs. This survey revealed, for the first time in Italy, the presence of psyllid Bactericera trigonica adults associated with 'Candidatus Liberibacter solanacearum' (Lso). This finding provided important evidence of the risks for Lso outbreaks and prompted further research to assess the spread and the incidence of the bacterium in crop cultivations in Italy. Psyllids, members of the family Triozidae, represent a potential threat to the cultivation of solanaceous and apiaceous crops worldwide, mainly as vectors of the phloem-restricted bacterium 'Candidatus Liberibacter solanacearum' (Lso). The Lso haplotypes C, D and E are known to affect apiaceous crops, such as carrot and celery, in several European countries. In Italy, data on the incidence and natural spread of both Lso and psyllids have not been reported so far. In this study, the presence of the vectors was investigated in a main Italian district for carrot production, the "Altopiano del Fucino" area (Central Italy). Both occasional and regular surveys were carried out on a total of five carrot fields and one potato field in 2021 and 2022. Bactericera trigonica (Hodkinson), which is known to efficiently transmit Lso to carrots, was found to be well-established in the area. High levels of population density were recorded in the summer period (more than 100 adult specimens per trap caught every two weeks) and then sharply decreased after the carrot harvest, confirming the strict association of this psyllid species with crop availability. In 2022, 27.5% of the total tested psyllid samples resulted in being positive for Lso haplotypes D and E, the latter being prevalent. This survey revealed, for the first time in Italy, the presence of B. trigonica adults associated with Lso in carrot crops. Although this study was limited to a few fields located in one area, it provided important evidence of the risks for Lso outbreaks and prompted further research to assess the spread and incidence of the disease in apiaceous cultivations in Italy. [ABSTRACT FROM AUTHOR]

'Candidatus Phytoplasma prunorum' is one of the most destructive pathogens of Prunus species, where susceptible species render unproductive several years after infection. In epidemiology, the molecular characterization of phytoplasmas is based on sequence analysis of variable nonribosomal genes. In this study aceF, pnp, imp and secY genes were used for characterization of the 'Ca. P. prunorum' genotypes present in the Czech Republic. In total, 56 plant and 33 vector (Cacopsylla pruni) samples positive to 'Ca. P. prunorum' collected in seven localities were used in the study. Based on sequence analysis, four aceF, two pnp, six imp, and three secY genotypes were identified in analyzed samples. The most abundant in both plant and insect samples were the A6, P2, I4, and S2 genotypes. Most of the Czech 'Ca. P. prunorum' haplotypes clustered together in the haplotype network analysis. Next, two isolates representing the two most abundant Czech haplotypes (A6-P2-I4-S2 and A5-P2-I4-S2) were used in the susceptibility test of three apricot rootstock types (St. Julien A, M-VA-1, GF-305). Susceptibility was analyzed by phytoplasma quantification using quantitative real-time PCR and evaluation of symptom manifestation. Based on the results, the influence of the rootstock type on the phytoplasma titer and symptom manifestation was greater than of the phytoplasma isolate, while the year of analysis had no influence on the results. The results also showed that the phytoplasma titer is increasing in plant tissues during the vegetation period. [ABSTRACT FROM AUTHOR]

A novel strain of Gram-negative, rod-shaped aerobic bacteria, identified as IY22, was isolated from the root nodules of Astragalus flavescens. The analysis of the 16S rDNA and recA (recombinase A) gene sequences indicated that the strain belongs to the genus Phyllobacterium. During the phylogenetic analysis, it was found that strain IY22 is closely related to P. trifolii strain PETP02T and P. bourgognense strain STM 201T. The genome of IY22 was determined to be 6,010,116 base pairs long with a DNA G+C ratio of 56.37 mol%. The average nucleotide identity (ANI) values showed a range from 91.7% to 93.6% when compared to its close relatives. Moreover, IY22 and related strains had digital DNA-DNA hybridization (dDDH) values ranging from 16.9% to 54.70%. Multiple genes (including nodACDSNZ, nifH/frxC, nifUS, fixABCJ, and sufABCDES) associated with symbiotic nitrogen fixation have been detected in strain IY22. Furthermore, this strain features genes that contribute to improving plant growth in various demanding environments. This study reports the first evidence of an association between A. flavescens and a rhizobial species. Native high-altitude legumes are a potential source of new rhizobia, and we believe that they act as a form of insurance for biodiversity against the threats of desertification and drought. [ABSTRACT FROM AUTHOR]

Philaenus spumarius (Linnaeus, 1758) (Hemiptera, Aphrophoridae) was recently classified as a pest due to its ability to act as a vector of the phytopathogen Xylella fastidiosa. This insect has been reported to harbour several symbiotic bacteria that play essential roles in P. spumarius health and fitness. However, the factors driving bacterial assemblages remain largely unexplored. Here, the bacteriome associated with different organs (head, abdomen, and genitalia) of males and females of P. spumarius was characterized using culturally dependent and independent methods and compared in terms of diversity and composition. The bacteriome of P. spumarius is enriched in Proteobacteria, Bacteroidota, and Actinobacteria phyla, as well as in Candidatus Sulcia and Cutibacterium genera. The most frequent isolates were Curtobacterium, Pseudomonas, and Rhizobiaceae sp.1. Males display a more diverse bacterial community than females, but no differences in diversity were found in distinct organs. However, the organ shapes the bacteriome structure more than sex, with the Microbacteriaceae family revealing a high level of organ specificity and the Blattabacteriaceae family showing a high level of sex specificity. Several symbiotic bacterial genera were identified in P. spumarius for the first time, including Rhodococcus, Citrobacter, Halomonas, Streptomyces, and Providencia. Differences in the bacterial composition within P. spumarius organs and sexes suggest an adaptation of bacteria to particular insect tissues, potentially shaped by their significance in the life and overall fitness of P. spumarius. Although more research on the bacteria of P. spumarius interactions is needed, such knowledge could help to develop specific bacterial-based insect management strategies. [ABSTRACT FROM AUTHOR]

Introduction: The potato psyllid Bactericera cockerelli is the insect vector of the fastidious bacterium 'Candidatus Liberibacter solanacearum'. The bacterium infects both B. cockerelli and plant species, causing zebra chip (ZC) disease of potato and vein-greening disease of tomato. Temperatures are known to influence the initiation and progression of disease symptom in the host plant, and seasonal transitions from moderate to high temperatures trigger psyllid dispersal migration to facilitate survival. Methods: 'Ca. L. solanacearum' -infected and uninfected psyllids were reared at previously established 'permissible', optimal, and'non-permissible' and temperatures of 18°C, 24°C, and 30°C, respectively. Gene expression profiles for 'Ca. L. solanacearum'-infected and -uninfected adult psyllids reared at different temperatures were characterized by Illumina RNA-Seq analysis. Bacterial genome copy number was quantified by real-time quantitative-PCR (qPCR) amplification. Results: Relative gene expression profiles varied in psyllids reared at the three experimental temperatures. Psyllids reared at 18°C and 30°C exhibited greater fold-change increased expression of stress- and 'Ca. L. solanacearum' invasionrelated proteins. Quantification by qPCR of bacterial genome copy number revealed that 'Ca. L. solanacearum' accumulation was significantly lower in psyllids reared at 18°C and 30°C, compared to 24°C. Discussion: Temperature is a key factor in the life history of potato psyllid and multiplication/accumulation of 'Ca. L. solanacearum' in both the plant and psyllid host, influences the expression of genes associated with thermal stress tolerance, among others, and may have been instrumental in driving the coevolution of the pathosystem. [ABSTRACT FROM AUTHOR]

The Gemmatimonadota phylum has been widely detected in diverse natural environments, yet their specific ecological roles in many habitats remain poorly investigated. Similarly, the Candidatus ARS69 phylum has been identified only in a few habitats, and literature on their metabolic functions is relatively scarce. In the present study, we investigated the ecological significance of phyla Ca. ARS69 and Gemmatimonadota in the Arctic glacier foreland (GF) ecosystems through genome-resolved metagenomics. We have reconstructed the first high-quality metagenome-assembled genome (MAG) belonging to Ca. ARS69 and 12 other MAGs belonging to phylum Gemmatimonadota from the three different Arctic GF samples. We further elucidated these two groups phylogenetic lineage and their metabolic function through phylogenomic and pangenomic analysis. The analysis showed that all the reconstructed MAGs potentially belonged to novel species. The MAGs belonged to Ca. ARS69 consist about 8296 gene clusters, of which only about 8% of single-copy core genes (n = 980) were shared among them. The study also revealed the potential ecological role of Ca. ARS69 is associated with carbon fixation, denitrification, sulfite oxidation, and reduction biochemical processes in the GF ecosystems. Similarly, the study demonstrates the widespread distribution of different classes of Gemmatimonadota across wide ranges of ecosystems and their metabolic functions, including in the polar region. Key points: • Glacier foreland ecosystems act as a natural laboratory to study microbial community structure. • We have reconstructed 13 metagenome-assembled genomes from the soil samples. • All the reconstructed MAGs belonged to novel species with different metabolic processes. • Ca. ARS69 and Gemmatimonadota MAGs were found to participate in carbon fixation and denitrification processes. [ABSTRACT FROM AUTHOR]

Candidatus Methylomirabilis-related bacteria conduct anaerobic oxidation of methane (AOM) coupling with NO2− reduction, and Candidatus Methanoperedens-related archaea perform AOM coupling with reduction of diverse electron acceptors, including NO3−, Fe (III), Mn (IV) and SO42−. Application of nitrogen fertilization favors the growth of these methanotrophs in agricultural fields. Here, we explored the vertical variations in community structure and abundance of the two groups of methanotrophs in a nitrogen-rich vegetable field via using illumina MiSeq sequencing and quantitative PCR. The retrieved Methylomirabilis-related sequences had 91.12%-97.32% identity to the genomes of known Methylomirabilis species, and Methanoperedens-related sequences showed 85.49%-97.48% identity to the genomes of known Methanoperedens species which are capable of conducting AOM coupling with reduction of NO3− or Fe (III). The Methanoperedens-related archaeal diversity was significantly higher than Methylomirabilis-related bacteria, with totally 74 and 16 operational taxonomic units, respectively. In contrast, no significant difference in abundance between the bacteria (9.19 × 103–3.83 × 105 copies g−1 dry soil) and the archaea (1.55 × 104–3.24 × 105 copies g−1 dry soil) was observed. Furthermore, the abundance of both groups of methanotrophs exhibited a strong vertical variation, which peaked at 30–40 and 20–30 cm layers, respectively. Soil water content and pH were the key factors influencing Methylomirabilis-related bacterial diversity and abundance, respectively. For the Methanoperedens-related archaea, both soil pH and ammonium content contributed significantly to the changes of these archaeal diversity and abundance. Overall, we provide the first insights into the vertical distribution and regulation of Methylomirabilis-related bacteria and Methanoperedens-related archaea in vegetable soils. Key points: • The archaeal diversity was significantly higher than bacterial. • There was no significant difference in the abundance between bacteria and archaea. • The abundance of bacteria and archaea peaked at 30–40 and 20–30 cm, respectively. [ABSTRACT FROM AUTHOR]

In terms of productivity, potential for spread, and area covered, citrus is regarded as one of the major fruit crops. Citrus fruits account for around 37% of all fruit produced, with mandarins and oranges making up nearly 21% of this total. These days, citrus greening disease (CGD) is a major concern. Citrus decline is a complicated issue that causes orchard output to gradually drop until it eventually results in unproductive orchards. Citrus greening, tristeza, and gradual decline are the most prevalent illnesses that cause citrus decline. This study's goal was to determine how common citrus greening illnesses are across Sargodha's citrus-growing tehsils and kinds. Data on prevalence, incidence, and severity were collected in Sargodha's several tehsils, including Shahpur, Bhalwal, Kot-Momin, and Sargodha. Using particular primer sets A2/J5 and OI1/OI2C, the pathogen was characterized from representative citrus greening disease samples. According to the results of the Citrus Greening Disease, Bhalwal had the highest incidence rate (53.33%). Shahpur had 50% of the highest disease severity, whereas Bhalwal had 25% of the lowest disease severity. Twenty symptomatic grape fruit samples, ten fruiter samples, fifteen kinnow samples, five musambi samples, and ten sweet orange samples had their DNA isolated using the CTAB method. The pathogen DNA was recovered from a sweet orange sample that exhibits definite signs of greening and kinnow. Musambi samples were also amplified, and the amplified PCR product was sequenced to examine genetic heterogeneity in several citrus cultivars. To check for variations that would be useful for managing diseases in the future, a phylogenetic tree was generated as part of the phylogenetic analysis process. [ABSTRACT FROM AUTHOR]

Increasing incidences of phytoplasma infestations in Almond trees warrants the better management approach to prevent yield losses. Disease management rely on identification of the pathogen based on molecular profiling. The present study aimed, to identify the phytoplasma agent in almond trees and to measure the biochemical responses it causes in the host. Direct and Nested PCRs performed using phytoplasma specific primer pairs 16S rRNA, detected the presence of phytoplasma agent in symptomatic trees but not in symptomless trees. Phylogeny based on the sequence analysis revealed that the infecting agent was closely related to 'Candidatus Phytoplasma phoenicium' (16SrIX‐B subgroup). Then the study was carried out to determine the responses of physiological and biochemical mechanisms in almond trees infected with phytoplasma. Total chlorophyll and protein contents of infected almond trees were lower compared to healthy control, on the other hand, the levels of catalase and peroxidase activity increased in infected trees. Higher levels of stress‐related metabolites such as proline (20.53–39.23 μmol/g), phenol (3.00–4.44 mg GAE/g), salicylic (94.96–138.22 ng SA/mg protein) and jasmonic acid (965.86–1465.10 ng JA/mg protein) were observed in infected trees compared to asymptomatic trees, respectively in healthy and infected trees. The results showed that the Ca. P. phoenicium, which was detected for the first time in Türkiye, was able to change the physiological and biochemical mechanisms. The pathogenic agent could possess a potential danger in almond production areas. It is crucially important that this agent should be considered in certification programs. [ABSTRACT FROM AUTHOR]

In this study, two lab-scale reactors were operated to evaluate the impact of exogenous folate on the start-up process of single-stage partial nitritation-anammox (SPNA). Folate at a dose of 0.5, 1.0, and 1.5 mg/L was continuously added into the experimental reactor (RI) at different operation stages. The highest nitrogen removal rate was 0.26 kg N/(m3•d) in RI with a nitrogen loading rate of 0.45 kg N/(m3•d), which was higher than that in the control reactor (RII) of 0.20 kg N/(m3•d). Moreover, the extracellular polymeric substances production in RI with 1.5 mg/L folate dosage was 264.24 ± 6.74 mg/gVSS, enhancing by 0.5-fold that of the RII, and the activity of hydrazine oxidase increased to the highest level of 0.37 ± 0.01 μmol cyt- c /(gVSS•s). Meanwhile, the activity of dehydrogenase in RI was enhanced from 796.39 ± 2.19 μg/(gVSS•min) to 819.17 ± 24.47 μg/(min•gVSS). The relative abundance of Candidatus Brocadia was 0.64 % at the end of phase 5 in RI whereas it remained at 0.25 % in RII. Function prediction showed that the nitrogen-related genes highly increased with the folate addition. [Display omitted] [ABSTRACT FROM AUTHOR]

'Candidatus Phytoplasma meliae' is a pathogen associated with chinaberry yellowing disease, which has become a major phytosanitary problem for chinaberry forestry production in Argentina. Despite its economic impact, no genome information of this phytoplasma has been published, which has hindered its characterization at the genomic level. In this study, we used a metagenomics approach to analyze the draft genome of the 'Ca. P. meliae' strain ChTYXIII. The draft assembly consisted of twenty-one contigs with a total length of 751.949 bp, and annotation revealed 669 CDSs, 34 tRNAs, and 1 set of rRNA operons. The metabolic pathways analysis showed that ChTYXIII contains the complete core genes for glycolysis and a functional Sec system for protein translocation. Our phylogenomic analysis based on 133 single-copy genes and genome-to-genome metrics supports the classification as unique 'Ca. P. species' within the MPV clade. We also identified 31 putative effectors, including a homolog to SAP11 and others that have only been described in this pathogen. Our ortholog analysis revealed 37 PMU core genes in the genome of 'Ca. P. meliae' ChTYXIII, leading to the identification of 2 intact PMUs. Our work provides important genomic information for 'Ca. P. meliae' and others phytoplasmas for the 16SrXIII (MPV) group. [ABSTRACT FROM AUTHOR]

A survey was conducted to determine the human tick-borne bacterial infections in the nymphs which were collected from Western Ghats' fringe forest areas. Tick nymphs were collected using the flagging method from the villages where cases Kyasanur Forest Disease (KFD) were previously reported in the states of Goa, Karnataka and Maharashtra. A total of 200 tick pools consisting of 4587 nymphs were tested by PCR for the detection of bacteria of public health importance, such as Coxiella burnetii and Rickettsia spp. Of these, four pools (4.8%) in Karnataka and three pools (4.4%) in Maharashtra were positive for Coxiella burnetii, while none of the samples from Goa state were positive. Rickettsia spp. were positively obtained from Maharashtra (51.5%), Goa (35.42%) and Karnataka (26.19%). The sequence results of Rickettsia spp. showed similarity to the spotted fever group Candidatus Rickettsia shennongii, Rickettsia conorii subsp. heilongjiangensis and Rickettsia spp. strain koreansis. Individuals are entering into the forest areas for various reasons are more likely to infect with Coxiella burnetii. and Rickettsia spp. [ABSTRACT FROM AUTHOR]

Objective To understand the community composition of tick - borne pathogens carried by Ixodes persulcatus and the co - infection of Candidatus Rickettsia tarasevichiae (CRT) and Beiji nairovirus (BJNV) in ticks in the Arshan area of the Inner Mongolia Autonomous Region. Methods Free ticks were collected from BaiLang Town, Arshan City, China, and identified by morphological and molecular biology. Total RNA was extracted from tick samples containing unknown pathogens, and cDNA was synthesized and analyzed by metagenomic next generation sequencing (mNGS). The emerging disease - causing pathogens with high abundance at the level of viral and bacterial genera were selected for the analysis of infections and co - infections. The infection of CRT and BJNV in ticks was detected by reverse transcription - polymerase chain reaction (RT - PCR). Sequencing results were analyzed for homology and phylogenetic relationships. Results A total of 617 ticks were collected in this study, all of which were I. persulcatus. High - throughput sequencing results showed that the bacterial composition at the genus level, Rickettsia had the highest abundance of about 77%, and at the species level, Rickettsia canadensis had the highest abundance of about 25%, CRT 1%. Viral composition was highest at the genus level for Orthonairovirus at approximately 60% abundance and at the species level for BJNV at approximately 45 % abundance. CRT and BJNV infections were detected in the samples with a pool positivity rate (PPR) of 96. 15% and 88. 46%, respectively, and there was a compound infection, with a minimum infection rate (MIR) of 3. 72% for the compound infection. Conclusion This study reveals the composition of active species in the microbial community of free - ranging I. persulcatus in Arshan area through mNGS, and find for the first time that CRT andBJNV co - infections exist in I. persulcatus in this area. Therefore, the potential public health risk of CRT and BJNV in this region should be assessed to prevent the occurrence of zoonotic diseases, and the outbreak surveillance of CRT and BJNV - induced diseases should be strengthened. [ABSTRACT FROM AUTHOR]

The effect of microplastics (MPs) retained in waste activated sludge (WAS) on anaerobic digestion (AD) performance has attracted more and more attention. However, their effect on thermophilic AD remains unclear. Here, the influence of polyvinyl chloride (PVC) MPs on methanogenesis and active microbial communities in mesophilic (37 °C) and thermophilic (55 °C) AD was investigated. The results showed that 1, 5, and 10 mg/L PVC MPs significantly promoted the cumulative methane yield in mesophilic AD by 5.62%, 7.36%, and 8.87%, respectively, while PVC MPs reduced that in thermophilic AD by 13.30%, 18.82%, and 19.99%, respectively. Moreover, propionate accumulation was only detected at the end of thermophilic AD with PVC MPs. Microbial community analysis indicated that PVC MPs in mesophilic AD enriched hydrolytic and acidifying bacteria (Candidatus Competibacter, Lentimicrobium, Romboutsia, etc.) together with acetoclastic methanogens (Methanosarcina, Methanosaeta). By contrast, most carbohydrate-hydrolyzing bacteria, propionate-oxidizing bacterium (Pelotomaculum), and Methanosarcina were inhibited by PVC MPs in thermophilic AD. Network analysis further suggested that PVC MPs significantly changed the relationship of key microorganisms in the AD process. A stronger correlation among the above genera occurred in mesophilic AD, which may promote the methanogenic performance. These results suggested that PVC MPs affected mesophilic and thermophilic AD of WAS via changing microbial activities and interaction. [ABSTRACT FROM AUTHOR]

As a result of metagenomic analysis of feces of farm animals, 5 genomes of alpha-proteobacteria of the candidate genus Enterousia of the order Rs-D84 were assembled. The genomes ranged in size from 850 to 984 kb and contained from 835 to 961 protein-coding genes. Analysis of the genomes showed that these bacteria have fermentative metabolism and could produce lactate and acetate. Most of the genes for the Embden−Meyerhof glycolytic pathway and the non-oxidative phase of the pentose phosphate pathway are present, but the genes for glucokinase, glucose-6-phosphate isomerase and transaldolase were not found. Enterousia lack aerobic and anaerobic respiratory pathways, complete pathways for the amino acid, lipid and nucleotide biosynthesis, as well as secreted glycoside hydrolases and conventional transporters for the import of sugars and amino acids. Enterousia appear to have adopted the lifestyle of a symbiont/parasite or a scavenger obtaining metabolites from other cells or lysed biomass. Comparative genome analysis revealed that genome reduction is a common trait of the vast majority of other members of the candidate order Rs-D84. [ABSTRACT FROM AUTHOR]