The comparative plastisphere microbial community profile at Kung Wiman beach unveils potential plastic-specific degrading microorganisms.

Background: Plastic waste is a global environmental issue that impacts the well-being of humans, animals, plants, and microorganisms. Microplastic contamination has been previously reported at Kung Wiman Beach, located in Chanthaburi province along with the Eastern Gulf of Thailand. Our research aimed to study the microbial population of the sand and plastisphere and isolate microorganisms with potential plastic degradation activity. Methods: Plastic and sand samples were collected from Kung Wiman Beach for microbial isolation on agar plates. The plastic samples were identified by Fourier-transform infrared spectroscopy. Plastic degradation properties were evaluated by observing the halo zone on mineral salts medium (MSM) supplemented with emulsified plastics, including polystyrene (PS), polylactic acid (PLA), polyvinyl chloride (PVC), and bis (2-hydroxyethyl) terephthalate (BHET). Bacteria and fungi were identified by analyzing nucleotide sequence analysis of the 16S rRNA and internal transcribed spacer (ITS) regions, respectively. 16S and ITS microbiomes analysis was conducted on the total DNA extracted from each sample to assess the microbial communities. Results: Of 16 plastic samples, five were identified as polypropylene (PP), four as polystyrene (PS), four as polyethylene terephthalate (PET), two as high-density polyethylene (HDPE), and one sample remained unidentified. Only 27 bacterial and 38 fungal isolates were found to have the ability to degrade PLA or BHET on MSM agar. However, none showed degradation capabilities for PS or PVC on MSM agar. Notably, Planococcus sp. PP5 showed the highest hydrolysis capacity of 1.64 ± 0.12. The 16S rRNA analysis revealed 13 bacterial genera, with seven showing plastic degradation abilities: Salipiger, Planococcus, Psychrobacter, Shewanella, Jonesia, Bacillus, and Kocuria. This study reports, for the first time of the BHET-degrading properties of the genera Planococcus and Jonesia. Additionally, The ITS analysis identified nine fungal genera, five of which demonstrated plastic degradation abilities: Aspergillus, Penicillium, Peacilomyces, Absidia, and Cochliobolus. Microbial community composition analysis and linear discriminant analysis effect size revealed certain dominant microbial groups in the plastic and sand samples that were absent under culture-dependent conditions. Furthermore, 16S and ITS amplicon microbiome analysis revealed microbial groups were significantly different in the plastic and sand samples collected. Conclusions: We reported on the microbial communities found on the plastisphere at Kung Wiman Beach and isolated and identified microbes with the capacity to degrade PLA and BHET.

Simultaneous decarbonization and phosphorus removal by Tetrasphaera elongata with glucose as carbon source under aerobic conditions.

Previous researches have recognized the vital role of Tetrasphaera elongata in enhanced biological phosphorus removal systems, but the underlying mechanisms remain under-investigated. To address this issue, this study investigated the metabolic characteristics of Tetrasphaera elongata when utilizing glucose as the sole carbon source. Results showed under aerobic conditions, Tetrasphaera elongata exhibited a glucose uptake rate of 136.6 mg/(L·h) and a corresponding phosphorus removal rate of 8.6 mg P/(L·h). Upregulations of genes associated with the glycolytic pathway and oxidative phosphorylation were observed. Noteworthily, the genes encoding the two-component sensor histidine kinase and response regulator transcription factor exhibited a remarkable 28.3 and 27.4-fold increase compared with the group without glucose. Since these genes play a pivotal role in phosphate-specific transport systems, collectively, these findings shed light on a potential mechanism for simultaneous decarbonization and phosphorus removal by Tetrasphaera elongata under aerobic conditions, providing fresh insights into phosphorus removal from wastewaters.

Cultivar-specific dynamics: unravelling rhizosphere microbiome responses to water deficit stress in potato cultivars.

BACKGROUND: Growing evidence suggests that soil microbes can improve plant fitness under drought. However, in potato, the world's most important non-cereal crop, the role of the rhizosphere microbiome under drought has been poorly studied. Using a cultivation independent metabarcoding approach, we examined the rhizosphere microbiome of two potato cultivars with different drought tolerance as a function of water regime (continuous versus reduced watering) and manipulation of soil microbial diversity (i.e., natural (NSM), vs. disturbed (DSM) soil microbiome). RESULTS: Water regime and soil pre-treatment showed a significant interaction with bacterial community composition of the sensitive (HERBST) but not the resistant cultivar (MONI). Overall, MONI had a moderate response to the treatments and its rhizosphere selected Rhizobiales under reduced watering in NSM soil, whereas Bradyrhizobium, Ammoniphilus, Symbiobacterium and unclassified Hydrogenedensaceae in DSM soil. In contrast, HERBST response to the treatments was more pronounced. Notably, in NSM soil treated with reduced watering, the root endophytic fungus Falciphora and many Actinobacteriota members (Streptomyces, Glycomyces, Marmoricola, Aeromicrobium, Mycobacterium and others) were largely represented. However, DSM soil treatment resulted in no fungal taxa and fewer enrichment of these Actinobacteriota under reduced watering. Moreover, the number of bacterial core amplicon sequence variants (core ASVs) was more consistent in MONI regardless of soil pre-treatment and water regimes as opposed to HERBST, in which a marked reduction of core ASVs was observed in DSM soil. CONCLUSIONS: Besides the influence of soil conditions, our results indicate a strong cultivar-dependent relationship between the rhizosphere microbiome of potato cultivars and their capacity to respond to perturbations such as reduced soil moisture. Our study highlights the importance of integrating soil conditions and plant genetic variability as key factors in future breeding programs aiming to develop drought resistance in a major food crop like potato. Elucidating the molecular mechanisms how plants recruit microbes from soil which help to mitigate plant stress and to identify key microbial taxa, which harbour the respective traits might therefore be an important topic for future research.

Streptomyces biostimulants: an effective sustainable approach to reduce inorganic N input and maintain high yield of wheat crop in different soil types.

AIMS: This study aimed to isolate and characterize endophytic plant growth-promoting (PGP) actinomycetes from the wild medicinal plant Zygophyllum album. METHODS AND RESULTS: Eight actinomycetes were isolated, identified, and screened for their PGP activities to improve the growth and production of wheat plants under low N-inputs. Based on 16S rRNA analysis, the isolated actinobacteria showed high diversity and had multiple in vitro PGP attributes. In pot experiments, Streptomyces sp. NGB-Act4 and NGB-Act6 demonstrated the highest significant PGP activities to enhance the growth of wheat plants under reduced N-inputs. Under various field conditions (high-fertility clay soils and low-fertility sandy soils), in combination with 50% N-dose, the two streptomycetes showed significant increases in grain N% and grain yield of the wheat crop compared with the 50% N-fertilized treatment. Irrespective of soil type, wheat plants inoculated with strain NGB-Act4 produced grain yield and grain N% significantly greater than or comparable to the full N-dose treatment. CONCLUSIONS: This is the first field report on the successful use of endophytic streptomycetes as an effective strategy to improve wheat yield and reduce the use of synthetic N fertilizers.

Microbiome assembly mechanism and functional potential in enhanced biological phosphorus removal system enriched with Tetrasphaera-related polyphosphate accumulating organisms.

Tetrasphaera-related polyphosphate accumulating organisms (PAOs) are the key functional guilds for enhanced biological phosphorus removal (EBPR) systems. Their biomass enrichment can be enhanced by the nitrification inhibitor allylthiourea (ATU). However, the underlying assembly mechanism and the functional potential of the EBPR microbiome regulated by ATU are unclear. This study investigates the effect of ATU on microbiome assembly and functional potential by closely following the microbiota dynamics in an EBPR system enriched with Tetrasphaera-related PAOs for 288-days before, during and after ATU addition. The results showed that ATU addition increased microbiota structural similarity and compositional convergence, and enhanced determinism in the assembly of EBPR microbiome. During exposure to ATU, Tetrasphaera-related PAOs were governed by homogeneous selection and the dominant species revealed by 16S rRNA gene-based phylogenetic analysis shifted from clade III to clade I. Meanwhile, ATU supply promoted significant enrichment of functional genes involved in phosphate transport (pit) and polyphosphate synthesis and degradation (ppk1 and ppk2), whereas both Nitrosomonas and ammonia monooxygenase-encoding genes (amoA/B/C) assignable to this group of nitrifying bacteria decreased. Moreover, ATU addition relieved the significant abundance correlation between filamentous bacteria Ca. Promineofilum and denitrifying Brevundimonas (FDR-adjusted P < 0.01), damaging their potential synergic or cooperative interactions, thus weakening their competitiveness against Tetrasphaera-related PAOs. Notably, ATU withdrawn created opportunistic conditions for the unexpected explosive growth and predominance of Thiothrix filaments, leading to a serious bulking event. Our study provides new insights into the microbial ecology of Tetrasphaera-related PAOs in EBPR system, which could guide the establishment of an efficient microbiota for EBPR.

Leucobacter allii sp. nov. and Leucobacter rhizosphaerae sp. nov., isolated from rhizospheres of onion and garlic, respectively.

Three bacterial strains, H21R-40T and H21R-36 from garlic (Allium sativum) and H25R-14T from onion (Allium cepa), were isolated from plant rhizospheres sampled in the Republic of Korea. Results of 16S rRNA gene sequence analysis revealed the highest sequence similarity of strain H21R-40T to Leucobacter celer subsp. astrifaciens CBX151T (97.3 %) and Leucobacter triazinivorans JW-1T (97.2 %), and strain H25R-14T to Leucobacter insecticola HDW9BT (98.8 %) and Leucobacter humi Re6T (98.4 %), while the sequence similarity between strains H21R-40T and H21R-36 was 99.8 %. According to the phylogenomic tree, strains H21R-40T with H21R-36 formed an independent clade separable from other Leucobacter species within the genus Leucobacter and strain H25R-14T clustered with Leucobacter insecticola HDW9BT, Leucobacter coleopterorum HDW9AT and Leucobacter viscericola HDW9CT. Strains H21R-40T and H21R-36 had orthologous average nucleotide identity (OrthoANI) and digital DNA-DNA hybridization (dDDH) values (98.1 % and 86.9 %, respectively) higher than the threshold ranges for species delineation (95-96 % and 70 %, respectively). The OrthoANI and dDDH values between two strains (H21R-40T and H25R-14T) and the type strains of species of the genus Leucobacter were lower than 81 and 24 %, respectively. The peptidoglycan type of three strains was type B1. The major menaquinones and major polar lipids of the strains were MK-11 and MK-10, and diphosphatidylglycerol, phatidylglycerol and an unidentified glycolipid, respectively. The major fatty acids (more than 10 % of the total fatty acids) of strains H21R-40T and H21R-36 were anteiso-C15 : 0, anteiso-C17 : 0 and iso-C16 : 0, and those of strain H25R-14T were anteiso-C15 : 0 and iso-C16 : 0. The phenotypic, chemotaxonomic and genotypic data obtained in this study showed that the strains represent two novel species of the genus Leucobacter, named Leucobacter allii sp. nov. (H21R-40T and H21R-36) and Leucobacter rhizosphaerae sp. nov. (H25R-14T). The respective type strains are H21R-40T (=DSM 114348T=JCM 35241T=KACC 21839T=NBRC 115481T) and H25R-14T (=DSM 114346T=JCM 35239T=KACC 21837T=NBRC 115479T).

Rathayibacter rubneri sp. nov. isolated from Allium cepa var. Rijnsburger, an onion landrace.

The novel, aerobic, Gram-stain-positive, rod-shaped bacterial strain, ZW T2_19T, was isolated from an onion sample (Allium cepa var. Rijnsburger). Analyses of the 16S rRNA gene sequence revealed that ZW T2_19T represented a member of the genus Rathayibacter but may represent a novel species of this genus. Analyses of the whole draft genome sequences, i.e. digital DNA-DNA hybridisation (dDDH) and average nucleotide identity (ANI) of ZW T2_19T and all type strains of species of the genus Rathayibacter confirmed that ZW T2_19T represents a novel species of the genus Rathayibacter. The genome size of ZW T2_19T is 4.01 Mbp and the DNA G+C content is 71.8 mol%. Glucose, mannose, rhamnose and ribose were detected as whole-cell sugars of ZW T2_19T. The major respiratory quinone of ZW T2_19T is menaquinone MK-10, at 78.9 %. The detected peptidoglycan type in ZW T2_19T is a variant of type B2γ with {Gly} [l-diaminobutyric acid (l-DAB)/l-homoserine (l-Hse)] d-Glu-l-DAB. Polar lipids in ZW T2_19T consisted of one diphosphatidylglycerol, one phosphatidylglycerol, seven glycolipids, one phospholipid and one lipid. The fatty acid profile of ZW T2_19T predominantly consisted of anteiso-C15 : 0 (53 %), iso-C16 : 0 (21 %) and anteiso-C17 : 0 (18 %). In addition, API 20NE, API 50CH, API Coryne, API ZYM, antibiotic susceptibility, haemolysis and growth at different temperatures and with different supplements was investigated. On the basis of the results obtained using this polyphasic approach, including molecular, phenotypic and biochemical analyses, we propose the novel species Rathayibacter rubneri with the type and only strain ZW T2_19T (= DSM 114294T = LMG 32700T).

Characterization of Streptomyces sp. KB1 and its cultural optimization for bioactive compounds production.

Background: Bioactive compounds (BCs) from natural resources have been extensively studied because of their use as models in the development of novel and important medical and biopreservative agents. One important source of BCs is microorganisms, particularly terrestrial bacteria of the order Actinomycetales. Methods: We characterized Streptomyces sp. KB1 by observing its morphology, physiology, and growth on different media using biochemical tests, optimizing cultural conditions by changing one independent variable at a time. Results: Streptomyces sp. KB1 (TISTR 2304) is a gram-positive and long filamentous bacteria that forms straight to flexuous (rectiflexibile) chains of globose-shaped and smooth-surfaced spores. It can grow under aerobic condition s only at a temperature range of 25-37 °C and initial pH range of 5-10 in the presence of sodium chloride 4% (w/v). Therefore, it is considered an obligate aerobe, mesophilic, neutralophilic, and moderately halophilic bacteria. The isolate grew well on peptone-yeast extract iron, Luria Bertani (LB), and a half-formula of LB (LB/2), but could not grow on MacConkey agar. It utilized fructose, mannose, glucose, and lactose as its carbon source along with acid production and showed positive reactions to casein hydrolysis, gelatin liquefaction, nitrate reduction, urease, and catalase production. Streptomyces sp. KB1 (TISTR 2304) could produce the maximum number of BCs when 1% of its starter was cultivated in a 1,000 ml baffled flask containing 200 ml of LB/2 broth with its initial pH adjusted to 7 with no supplemental carbon source, nitrogen source, NaCl, or trace element at 30 °C, shaken at 200 rpm in an incubator for 4 days.

Solicola gregarius gen. nov., sp. nov., a soil actinobacterium isolated after enhanced cultivation with Micrococcus luteus culture supernatant.

An actinobacterial strain, designated A5X3R13T, was isolated from a compost soil suspension supplemented with extracellular material from a Micrococcus luteus-culture supernatant. The strain was cultured on tenfold-diluted reasoner's 2A agar. The cells were ovoid-to-rod shaped, non-motile, Gram-stain-positive, oxidase-negative, catalase-positive and had a width of 0.5 µm and a length of 0.8-1.2 µm. The results of both 16S rRNA-based phylogenetic and whole-genome analyses indicate that A5X3R13T forms a distinct lineage within the family Nocardioidaceae (order Propionibacteriales). On the basis of the 16S rRNA gene sequence, A5X3R13T was closely related to Aeromicrobium terrae CC-CFT486T (96.2 %), Nocardioides iriomotensis IR27-S3T (96.2 %), Nocardioides guangzhouensis 130T (95.6 %), Marmoricola caldifontis YIM 730233T (95.5 %), Aeromicrobium alkaliterrae KSL-107T (95.4 %), Aeromicrobium choanae 9H-4T (95.4 %), Aeromicrobium panaciterrae Gsoil 161T (95.3 %), and Nocardioides jensenii NBRC 14755T (95.2 %). The genome had a length of 4 915 757 bp, and its DNA G+C content was 68.5 mol %. The main fatty acids were 10-methyl C17 : 0, C16 : 0, C15 : 0, C18 : 0, C17 : 0 and iso-C16 : 0. The main polar lipids were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylinositol and two unidentified phospholipids. MK-9(H4) was the predominant respiratory quinone. The peptidoglycan type was A3γ (A41.1) and contained alanine, glycine, glutamic acid and ll-diaminopimelic acid in a molar ratio of 1.2 : 0.9 : 1.0 : 0.8. On the basis of the results of the phylogenetic and phenotypic analyses and comparisons with other members of the family Nocardioidaceae, strain A5X3R13T is proposed to represent a novel species within a novel genus, for which the name Solicola gregarius gen. nov., sp. nov. is proposed. The type strain is A5X3R13T (=DSM 112953T=NCCB 100840T).

Bioaugmentation with Tetrasphaera to improve biological phosphorus removal from anaerobic digestate of swine wastewater.

Tetrasphaera-enhanced biological phosphorus removal (T-EBPR) was developed by augmenting conventional EBPR (C-EBPR) with Tetrasphaera to improve phosphorus removal from anaerobic digestate of swine wastewater. At influent total phosphorus (TP) concentrations of 45-55 mg/L, T-EBPR achieved effluent TP concentration of 4.17 ± 1.02 mg/L, 54 % lower than that in C-EBPR (8.98 ± 0.76 mg/L). The enhanced phosphorous removal was presumably due to the synergistic effect of Candidatus Accumulibacter and Tetrasphaera occupying different ecological niches. Bioaugmentation with Tetrasphaera promoted the polyphosphate accumulation metabolism depending more on the glycolysis pathway, as evidenced by an increase in intracellular storage compounds of glycogen and polyhydroxyalkanoates by 0.87 and 0.34 mmol C/L, respectively. The enhanced intracellular storage capacity was coincidentally linked to the increase in phosphorus release and uptake rates by 1.23 and 1.01 times, respectively. These results suggest bioaugmentation with Tetrasphaera could be an efficient way for improved phosphorus removal from high-strength wastewater.

Curtobacterium allii sp. nov., the actinobacterial pathogen causing onion bulb rot.

A Gram-stain-positive, aerobic, and non-spore-forming bacterial strain, 20TX0166T, was isolated from a diseased onion bulb in Texas, USA. Upon testing its pathogenicity on onion bulb, it produced pathogenic response which makes it first species of pathogen belonging to the phylum actinobacteria detected in onion. Phylogenetic analysis of the 16S rRNA gene sequence revealed that the strain belonged to the genus Curtobacterium and was most similar to Curtobacterium flaccumfaciens LMG 3645T (100%), C. pusillum DSM 20527T (99.5%), and C. oceanosedimentum ATCC 31317T (99.5%). The estimated genome size of the novel species was 4.0 Mbp with a G + C content of 70.8%. The orthologous ANI (orthoANIu), ANI based on blast (ANIb), and dDDH values between the novel strain and the closest relative, C. flaccumfaciens LMG 3645T, were 95.7%, 95.4%, and 63.3%, respectively. These values were below the recommended species cut-off threshold of 96% (ANI) and 70% (dDDH), suggesting the strain may be a novel species. Physiologic and phenotypic characters of this novel strain were also unique when compared with the closely related species. The major cellular fatty acids of this strain were anteiso-C15:0 and anteiso-C17:0. Using a polyphasic approach based on phenotypic and genotypic analyses, strain 20TX0166T represents a novel species of the genus Curtobacterium, and the name Curtobacterium allii sp. nov. is proposed. The type strain is 20TX0166T (= LMG 32517T = CIP112023T = NCIMB 15427T).

Cyclopeptide Alkaloids from Discaria chacaye (Rhamnaceae) as Result of Symbiosis with Frankia (Actinomycetales).

Cyclopeptide alkaloids with different biological activities are present in plants of the family Rhamnaceae. Plants of this family grow in a symbiotic relationship with aerobic Gram-positive actinomycetes belonging to the genus Frankia. This goal of this research was a study of the comparative profile of alkaloids present in Discaria chacaye and to establish a connection between the presence or absence of Frankia sp. and the alkaloids. In addition, insecticidal activities of the alkaloidal extract were examined. A total of 24 alkaloids were identified, of which 12 have a benzylisoquinoline skeleton, 9 were cyclopeptides, 2 isoquinolines, and 1 aporphine. The presence of cyclopeptide alkaloids is associated with Frankia nodules in the plant root. The alkaloid extracts showed insecticidal activity with mortality dose-dependence and LD50 values between 44 to 71 µg/mL.

Research advances of the phosphorus-accumulating organisms of Candidatus Accumulibacter, Dechloromonas and Tetrasphaera: Metabolic mechanisms, applications and influencing factors.

Phosphorus-accumulating organisms (PAOs), which harbor metabolic mechanisms for phosphorus removal, are widely applied in wastewater treatment. Recently, novel PAOs and phosphorus removal metabolic pathways have been identified and studied. Specifically, Dechloromonas and Tetrasphaera can remove phosphorus via the denitrifying phosphorus removal and fermentation phosphorus removal pathways, respectively. As the main PAOs in biological phosphorus removal systems, the conventional PAO Candidatus Accumulibacter and the novel PAOs Dechloromonas and Tetrasphaera are thoroughly discussed in this paper, with a specific focus on their phosphorus removal metabolic mechanisms, process applications, community abundance and influencing factors. Dechloromonas can achieve simultaneous nitrogen and phosphorus removal in an anoxic environment through the denitrifying phosphorus removal metabolic pathway, which can further reduce carbon source requirements and aeration energy consumption. The metabolic pathways of Tetrasphaera are diverse, with phosphorus removal occurring in conjunction with macromolecular organics degradation through anaerobic fermentation. A collaborative oxic phosphorus removal pathway between Tetrasphaera and Ca. Accumulibacter, or a collaborative anoxic denitrifying phosphorus removal pathway between Tetrasphaera and Dechloromonas are future development directions for biological phosphorus removal technologies, which can further reduce carbon source and energy consumption while achieving enhanced phosphorus removal.

Nocardioides panacis sp. nov., isolated from soil of a ginseng field.

A bacterial strain designated as G188T was isolated from ginseng field soil in the Republic of Korea. Phylogenetic analysis of 16S rRNA gene sequences showed that strain G188T formed a distinct lineage within the genus Nocardioides, family Nocardioidaceae, order Propionibacteriales. Sequence similarity revealed that strain G188T was most closely related to Nocardioides iriomotensis IR27-S3T (97.7 % 16S rRNA similarity). The genome size of strain G188T was 4 901 775 bp, and the genomic DNA G+C content was 72.3 mol%. The average nucleotide identity and DNA-DNA hybridization values with other Nocardioides species were less than 75.6 and 20.1 %, respectively. The main fatty acids of strain G188T were C17 : 0, C17 : 1 ω8c and iso-C16 : 0. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylinositol, and the major respiratory quinone was menaquinone 8, supporting that strain G188T was affiliated with the genus Nocardioides. Based on biochemical, chemotaxonomic and phylogenetic analyses, the novel species Nocardioides panacis G188T (KACC 21695T=LMG 31733T) is proposed.

Effect of thermotherapy, Leifsonia xyli subsp. xyli titres, sugarcane genotype and diagnostic techniques on ratoon stunt control in Brazil.

AIMS: To examine the interaction of diagnostic techniques, initial titres of Leifsonia xyli subsp. xyli (Lxx), sugarcane genotype and thermotherapy on ratoon stunt (RSD) control. METHODS AND RESULTS: Single buds of RB867515, RB92579 and RB966928 were submitted to 50°C/2 h or 52°C/30 min under factorial block design and five replications; results were checked 9 months later by serological (DBI) and molecular (PCR) techniques. A 10,000 bootstrapping simulations were performed to infer the best plot size based on the experimental coefficient of variation. Analysis of variance showed significance only on initial Lxx titres and RSD control. Despite the absence of significance in the overall analysis, minor differences in control success with different methods and cultivars are predicted to have a major epidemiological impact on RSD, considering successive harvests and vegetative increase. According to an epidemiological interpretation, the 50°C/2 h treatment was more effective, cultivar RB966928 was the most susceptible and the PCR-based method was the most sensitive for pathogen detection. The minimum required plants per plot was 15, indicating high precision of our experiment CONCLUSIONS: Data interpretation considered both the statistical analysis and the epidemiology aspect of RSD in order to improve RSD management. The Brazilian sugarcane industry will benefit from this approach since it is not using it. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first study that examined multiple factors that affect RSD control. Our work pinpointed the importance of the thermotherapy, its best combination as well as the diagnostic test. Also, the effect of the cultivar to respond to management strategies. Because the epidemiological aspect of RSD was taken into consideration, results of our work can have an impact on RSD control in the field.

Phosphorus removal performance, intracellular metabolites and clade-level community structure of Tetrasphaera-dominated polyphosphate accumulating organisms at different temperatures.

Tetrasphaera are polyphosphate accumulating organisms (PAOs) that play an important role in enhanced biological phosphorus removal (EBPR) from wastewater. The effect of a wide range of temperature changes (1-30 °C) on phosphorus removal, metabolism and clade-level community structure of Tetrasphaera-dominated PAOs was investigated. At 10 °C, the bioactivities of Tetrasphaera-dominated communities were obviously inhibited and the EBPR efficiency was only 73 %. Yet at 20-30 °C, EBPR efficiency reached 99 % and the relative abundance of Tetrasphaera was up to 90 %. The temperature variation changed the community distribution of Tetrasphaera clades, which was possibly a main reason for EBPR performance. Amino acids and PHA with different contents were intracellular metabolite of Tetrasphaera-dominated communities during phosphorus release and uptake at different temperatures. Moreover, Tetrasphaera fermented protein and amino acids and released VFAs. The outcomes suggested the great potential of Tetrasphaera-PAOs in the treatment of wastewater with varying temperatures and limited carbon sources.

Nocardioides carbamazepini sp. nov., an ibuprofen degrader isolated from a biofilm bacterial community enriched on carbamazepine.

From the metagenome of a carbamazepine amended selective enrichment culture the genome of a new to science bacterial species affiliating with the genus Nocardioides was reconstructed. From the same enrichment an aerobic actinobacterium, strain CBZ_1T, sharing 99.4% whole-genome sequence similarity with the reconstructed Nocardioides sp. bin genome was isolated. On the basis of 16S rRNA gene sequence similarity the novel isolate affiliated to the genus Nocardioides, with the closest relatives Nocardioides kongjuensis DSM19082T (98.4%), Nocardioides daeguensis JCM17460T (98.4%) and Nocardioides nitrophenolicus DSM15529T (98.2%). Using a polyphasic approach it was confirmed that the isolate CBZ_1T represents a new phyletic lineage within the genus Nocardioides. According to metagenomic, metatranscriptomic studies and metabolic analyses strain CZB_1T was abundant in both carbamazepine and ibuprofen enrichments, and harbors biodegradative genes involved in the biodegradation of pharmaceutical compounds. Biodegradation studies supported that the new species was capable of ibuprofen biodegradation. After 7 weeks of incubation, in mineral salts solution supplemented with glucose (3 g l-1) as co-substrate, 70% of ibuprofen was eliminated by strain CBZ_1T at an initial conc. of 1.5 mg l-1. The phylogenetic, phenotypic and chemotaxonomic data supported the classification of strain CBZ_1T to the genus Nocardioides, for which the name Nocardioides carbamazepini sp. nov. (CBZ_1T = NCAIM B.0.2663 = LMG 32395) is proposed. To the best of our knowledge, this is the first study that reports simultaneous genome reconstruction of a new to science bacterial species using metagenome binning and at the same time the isolation of the same novel bacterial species.

Histopathology of the Shoot Apex of Sugarcane Colonized by Leifsonia xyli subsp. xyli.

Colonization of the xylem of sugarcane by Leifsonia xyli subsp. xyli results in the occlusion of the vessels by a gum-like compound and compromises the elongation of the stalk leading to stunted plants. However, no study has been performed in the apical tissue where the elongation of the stalks initiates at the intercalary meristem (IM). Microscopic and histochemical analyses were performed in plants with lower and higher bacterial titers and revealed that in both cases L. xyli subsp. xyli is present in this tissue and colonizes the forming xylem vessels in a similar way as observed in developed internodes. In both cases, it was observed adhering to the secondary walls, but only in plants with higher titers were a mild degradation of the walls and a granular material filling the vessels observed. The mixed composition of lipids, proteins, and pectin indicates that the filling is not a bacterial extracellular polymeric substance. Plants with higher bacterial populations also presented lower starch content in the ground parenchyma at the node elements, possibly resulting from the reported downregulation of photosynthesis and increased accumulation of phenolics. Their second and third IMs presented fewer cells and reduced expression of genes related to the cell cycle and to the synthesis of ABA in the apical tissue. These results indicate that increased L. xyli subsp. xyli colonization affects the development of the IM, which ultimately would reduce the length of the internodes, resulting in the main symptom of the disease.

Carbon uptake bioenergetics of PAOs and GAOs in full-scale enhanced biological phosphorus removal systems.

This work analyzed, for the first time, the bioenergetics of PAOs and GAOs in full-scale wastewater treatment plants (WWTPs) for the uptake of different carbon sources. Fifteen samples were collected from five full-scale WWTPs. Predominance of different PAOs, i.e., Ca. Accumulibacter (0.00-0.49%), Tetrasphaera (0.37-3.94%), Microlunatus phosphovorus (0.01-0.18%), etc., and GAOs, i.e., Ca. Competibacter (0.08-5.39%), Defluviicoccus (0.05-5.34%), Micropruina (0.17-1.87%), etc., were shown by 16S rRNA gene amplicon sequencing. Despite the distinct PAO/GAO community compositions in different samples, proton motive force (PMF) was found as the key driving force (up to 90.1%) for the uptake of volatile fatty acids (VFAs, acetate and propionate) and amino acids (glutamate and aspartate) by both GAOs and PAOs at the community level, contrasting the previous understanding that Defluviicoccus have a low demand of PMF for acetate uptake. For the uptake of acetate or propionate, PAOs rarely activated F1, F0- ATPase (< 11.7%) or fumarate reductase (< 5.3%) for PMF generation; whereas, intensive involvements of these two pathways (up to 49.2% and 61.0%, respectively) were observed for GAOs, highlighting a major and community-level difference in their VFA uptake biogenetics in full-scale systems. However, different from VFAs, the uptake of glutamate and aspartate by both PAOs and GAOs commonly involved fumarate reductase and F1, F0-ATPase activities. Apart from these major and community-level differences, high level fine-scale micro-diversity in carbon uptake bioenergetics was observed within PAO and GAO lineages, probably resulting from their versatilities in employing different pathways for reducing power generation. Ca. Accumulibacter and Halomonas seemed to show higher dependency on the reverse operation of F1, F0-ATPase than other PAOs, likely due to the low involvement of glyoxylate shunt pathway. Unlike Tetrasphaera, but similar to Ca. Accumulibacter, Microlunatus phosphovorus took up glutamate and aspartate via the proton/glutamate-aspartate symporter driven by PMF. This feature was testified using a pure culture of Microlunatus phosphovorus stain NM-1. The major difference between PAOs and GAOs highlights the potential to selectively suppress GAOs for community regulation in EBPR systems. The finer-scale carbon uptake bioenergetics of PAOs or GAOs from different lineages benefits in understanding their interactions in community assembly in complex environment.

The novel genus, 'Candidatus Phosphoribacter', previously identified as Tetrasphaera, is the dominant polyphosphate accumulating lineage in EBPR wastewater treatment plants worldwide.

The bacterial genus Tetrasphaera encompasses abundant polyphosphate accumulating organisms (PAOs) that are responsible for enhanced biological phosphorus removal (EBPR) in wastewater treatment plants. Recent analyses of genomes from pure cultures revealed that 16S rRNA genes cannot resolve the lineage, and that Tetrasphaera spp. are from several different genera within the Dermatophilaceae. Here, we examine 14 recently recovered high-quality metagenome-assembled genomes from wastewater treatment plants containing full-length 16S rRNA genes identified as Tetrasphaera, 11 of which belong to the uncultured Tetrasphaera clade 3. We find that this clade represents two distinct genera, named here Ca. Phosphoribacter and Ca. Lutibacillus, and reveal that the widely used model organism Tetrasphaera elongata is less relevant for physiological predictions of this uncultured group. Ca. Phosphoribacter incorporates species diversity unresolved at the 16S rRNA gene level, with the two most abundant and often co-occurring species encoding identical V1-V3 16S rRNA gene amplicon sequence variants but different metabolic capabilities, and possibly, niches. Both Ca. P. hodrii and Ca. P. baldrii were visualised using fluorescence in situ hybridisation (FISH), and PAO capabilities were confirmed with FISH-Raman microspectroscopy and phosphate cycling experiments. Ca. Phosphoribacter represents the most abundant former Tetrasphaera lineage and PAO in EPBR systems in Denmark and globally.