Clade IA Research Articles

Clade I mpox virus genomic diversity in the Democratic Republic of the Congo, 2018–2024: Predominance of zoonotic transmission

Recent reports raise concerns on the changing epidemiology of mpox in the Democratic Republic of the Congo (DRC). High-quality genomes were generated for 337 patients from 14/26 provinces to document whether the increase in number of cases is due to zoonotic spillover events or viral evolution, with enrichment of APOBEC3 mutations linked to human adaptation. Our study highlights two patterns of transmission contributing to the source of human cases. All new sequences from the eastern South Kivu province (n= 17; 4.8%) corresponded to the recently described clade Ib, associated with sexual contact and sustainedhuman-to-human transmission. By contrast, all other genomes are clade Ia, which exhibits high genetic diversity with low numbers of APOBEC3 mutations compared with clade Ib, suggesting multiplezoonotic introductions. The presence of multiple clade I variants in urban areas highlights the need for coordinated international response efforts and more studies on the transmission and the reservoir of mpox.

International external quality assessment study for detection of monkeypox virus by PCR supporting laboratory preparedness during the 2022–2023 mpox outbreak and beyond

BackgroundDiagnostic capabilities and correspondent External Quality Assessments (EQA) are key for outbreak preparedness. To support diagnostic facilities with a quality assessment of newly established monkeypox virus (MPXV) molecular diagnostic workflows, Quality Control for Molecular Diagnostics (QCMD) and the Bundeswehr Institute of Microbiology (IMB) piloted an international EQA study conducting four challenges from autumn 2022 to summer 2023 during the global mpox outbreak. ObjectivesTo assess the performance (sensitivity/specificity) of molecular assays used by diagnostic laboratories. Study designInactivated EQA panels were prepared and distributed containing seven samples of clade Ia and clade IIb MPXV strains at different viral concentrations, two specificity controls with other zoonotic orthopoxviruses (vaccinia and cowpox virus) and a negative control. Assessment was based on reported qualitative testing results. ResultsIn this outbreak-related EQA study, a total of 192 laboratories from 37 countries reported 346 qualitative datasets. Overall, core samples were correctly detected by approximately 92 % of participants in all four challenges. While sensitivity performance was acceptable in at least 90 % of datasets correctly reported even for educational MPXV-positive samples with low viral concentration [102 genome equivalents (GE)/mL], several laboratories reported the educational specificity controls as false positives or were unable to differentiate MPXV from related orthopoxviruses. ConclusionsMpox is now a globally occurring infection with a demand for quality-assured diagnostic capabilities. The newly established EQA scheme presented here, offers a multi-purpose panel for orthopoxviruses with a focus on MPXV which will continue to ensure diagnostic quality in clinical settings with up-to-date sample panels.

Improved genome assembly of Candida auris strain B8441 and annotation of B11205.

Candida auris is a fungal pathogen of significant worldwide concern, typically resistant to one or more antifungal drugs. We report a completed genome for clade Ia isolate B8441 and gene annotations of clade Ic isolate B11205. These resources will support public health investigations and population genomic studies of this pathogen.

Genetic sequencing analysis of monkeypox virus clade I in Republic of the Congo: a cross-sectional, descriptive study

Monkeypox virus clade I is endemic in several central African countries and characterised by an increase in disease severity and mortality. Since October, 2023, a large-scale mpox outbreak has emerged in DR Congo, and in March, 2024, the first individuals with mpox were reported outside the endemic areas in Republic of the Congo. We aimed to provide insight into the epidemic by sequencing samples obtained from individuals with mpox in Republic of the Congo. In this cross-sectional, descriptive study, samples were collected from individuals with suspected mpox between Jan 15 and April 8, 2024, in Brazzaville, Pointe-Noire, Likouala, Cuvette-Centrale, and Plateaux (Republic of the Congo). Blood samples, skin or oropharyngeal swabs, or skin crusts were obtained for molecular diagnosis via real-time PCR. Monkeypox virus sequences were obtained and analysed using newly established nanopore sequencing methodology and bioinformatic pipeline. The sequences obtained were aligned and used to construct a maximum likelihood phylogenetic tree using IG-TREE. 61 samples were collected from individuals with suspected mpox, 31 of which were positive for monkeypox virus and were included in our analysis (four positive samples were excluded due to unavailability of epidemiological data or insufficient biological material). Individuals who tested positive for monkeypox virus were from Cuvette-Centrale (19 [61%] of 31), Likouala (eight [26%]), and Pointe-Noire (four [13%]). 20 (65%) were male and 11 (35%) were female. Phylogenetic analysis of sequences showed two major clusters within clade Ia. One cluster was made up of four sequences from this study clustering with two monkeypox virus sequences from the current DR Congo outbreak, three older sequences from Central African Republic sequenced between 2017 and 2018, and seven sequences from DR Congo sequenced in 2006-07 and 2022. The second cluster was made up of 16 sequences from this study clustering with sequences from the current DR Congo outbreak. In addition, sequences from Republic of the Congo show multiple phylogenetic positioning suggesting the occurrence of multiple co-circulating strains in the human population. Our findings suggest that multiple monkeypox virus strains are co-circulating in the human population, highlighting the need for implementation of expanded mpox surveillance, especially in countries bordering DR Congo and Republic of the Congo, in combination with control measures focused on containing the current outbreaks in these countries to prevent escalation into a larger-scale epidemic. Intramural Research Program of the National Institute of Allergy and Infectious Diseases at the National Institutes of Health.

SCPL acyltransferases catalyze the metabolism of chlorogenic acid during purple coneflower seed germination.

The metabolism of massively accumulated chlorogenic acid is crucial for the successful germination of purple coneflower (Echinacea purpurea (L.) Menoch). A serine carboxypeptidase-like (SCPL) acyltransferase (chicoric acid synthase, CAS) utilizes chlorogenic acid to produce chicoric acid during germination. However, it seems that the generation of chicoric acid lags behind the decrease in chlorogenic acid, suggesting an earlier route of chlorogenic acid metabolism. We discovered another chlorogenic acid metabolic product, 3,5-dicaffeoylquinic acid, which is produced before chicoric acid, filling the lag phase. Then, we identified two additional typical clade IA SCPL acyltransferases, named chlorogenic acid condensing enzymes (CCEs), that catalyze the biosynthesis of 3,5-dicaffeoylquinic acid from chlorogenic acid with different kinetic characteristics. Chlorogenic acid inhibits radicle elongation in a dose-dependent manner, explaining the potential biological role of SCPL acyltransferases-mediated continuous chlorogenic acid metabolism during germination. Both CCE1 and CCE2 are highly conserved among Echinacea species, supporting the observed metabolism of chlorogenic acid to 3,5-dicaffeoylquinic acid in two Echinacea species without chicoric acid accumulation. The discovery of SCPL acyltransferase involved in the biosynthesis of 3,5-dicaffeoylquinic acid suggests convergent evolution. Our research clarifies the metabolism strategy of chlorogenic acid in Echinacea species and provides more insight into plant metabolism.

The coconut rhinoceros beetle (Oryctes rhinoceros) outbreak is well established on Efate, Vanuatu

AbstractThe presence of coconut rhinoceros beetle (CRB: Oryctes rhinoceros) was reported on Efate, Vanuatu in 2019. The beetle population was determined to belong to the CRB‐S group (Clade II), similar to populations found in the Bismark Archipelago, Papua New Guinea. An introduction of the CRB‐G group (Clade IA) was discovered in 2021. Damage mapping, beetle trapping and genomic identification show that CRB‐S has now spread around about half of the island from the site of the original introduction. CRB‐G is mainly restricted to the seaport and surrounding areas of Port Vila with some outlying specimens. Through the efforts of Biosecurity Vanuatu, O. rhinoceros is still contained on the Efate group of islands and has not spread to the major copra‐producing islands in other parts of the country. Sanitation efforts appear to have reduced damage from coconut rhinoceros beetle within the zone of first arrival of the pest (Mangaliliu, Efate). Oryctes rhinoceros damage, however, is severe in areas with old plantations and limited sanitation activities (e.g. Mele/Devil's point, Efate). A concerted effort is necessary to contain the beetle on Efate and to reduce further spread and impact on the island.

Coconut rhinoceros beetle in Solomon Islands: a tale of two invasions

Coconut rhinoceros beetle (Oryctes rhinoceros; CRB) was discovered in 2015 in a small outbreak in Honiara, Guadalcanal, Solomon Islands. This was the first record of CRB from Solomon Islands and a response plan was prepared. An awareness programme was launched and where CRB sightings were confirmed, delimitation surveys were carried out. Following the launch of the awareness programme, later in 2015, CRB was also reported from the Shortland Islands in the Western Province. Other islands were surveyed from 2015 to 2020. If CRB presence was confirmed, beetles were collected and analysed for haplotype and presence of the classical biological control agent, Oryctes rhinoceros nudivirus (OrNV). A distribution map and timeline of invasion were developed. The initial populations belonged to two distinct haplotypes: CRB-G (clade IA) in Honiara and CRB-S (clade II) in Shortland Islands. Despite control measures, by 2020 CRB-G had spread to islands in eight provinces and CRB-S had spread to islands in seven provinces. CRB-S and CRB-G co-occur in Guadalcanal and Malaita provinces. In 2019, OrNV was detected from field collected CRB from Guadalcanal and has since spread to Malaita Island. In both cases the virus was detected where CRB-G and CRB-S co-occur. Other outbreak areas in Solomon Islands remain OrNV-free. The two haplotypes appear to have spread following patterns of air and sea movement between the point of origin (CRB-G from Honiara and CRB-S from the Shortland Islands) to other islands/provinces.

Human Infection Challenge with Serotype 3 Pneumococcus.

Rationale: Streptococcus pneumoniae serotype 3 (SPN3) is a cause of invasive pneumococcal disease and associated with low carriage rates. Following the introduction of pediatric 13-valent pneumococcal conjugate vaccine (PCV13) programs, SPN3 declines are less than other vaccine serotypes and incidence has increased in some populations coincident with a shift in predominant circulating SPN3 clade, from I to II. A human challenge model provides an effective means for assessing the impact of PCV13 on SPN3 in the upper airway. Objectives: To establish SPN3's ability to colonize the nasopharynx using different inoculum clades and doses, and the safety of an SPN3 challenge model. Methods: In a human challenge study involving three well-characterized and antibiotic-sensitive SPN3 isolates (PFESP306 [clade Ia], PFESP231 [no clade], and PFESP505 [clade II]), inoculum doses (10,000, 20,000, 80,000, and 160,000 cfu/100 μl) were escalated until maximal colonization rates were achieved, with concurrent acceptable safety. Measurement and Main Results: Presence and density of experimental SPN3 nasopharyngeal colonization in nasal wash samples, assessed using microbiological culture and molecular methods, on Days 2, 7, and 14 postinoculation. A total of 96 healthy participants (median age 21, interquartile range 19-25) were inoculated (n = 6-10 per dose group, 10 groups). Colonization rates ranged from 30.0-70.0% varying with dose and isolate. 30.0% (29/96) reported mild symptoms (82.8% [24/29] developed a sore throat); one developed otitis media requiring antibiotics. No serious adverse events occurred. Conclusions: An SPN3 human challenge model is feasible and safe with comparable carriage rates to an established Serotype 6B human challenge model. SPN3 carriage may cause mild upper respiratory symptoms.

Insights into acylation mechanisms: co-expression of serine carboxypeptidase-like acyltransferases and their non-catalytic companion paralogs.

SUMMARYSerine carboxypeptidase‐like acyltransferases (SCPL‐ATs) play a vital role in the diversification of plant metabolites. Galloylated flavan‐3‐ols highly accumulate in tea (Camellia sinensis), grape (Vitis vinifera), and persimmon (Diospyros kaki). To date, the biosynthetic mechanism of these compounds remains unknown. Herein, we report that two SCPL‐AT paralogs are involved in galloylation of flavan‐3‐ols: CsSCPL4, which contains the conserved catalytic triad S‐D‐H, and CsSCPL5, which has the alternative triad T‐D‐Y. Integrated data from transgenic plants, recombinant enzymes, and gene mutations showed that CsSCPL4 is a catalytic acyltransferase, while CsSCPL5 is a non‐catalytic companion paralog (NCCP). Co‐expression of CsSCPL4 and CsSCPL5 is likely responsible for the galloylation. Furthermore, pull‐down and co‐immunoprecipitation assays showed that CsSCPL4 and CsSCPL5 interact, increasing protein stability and promoting post‐translational processing. Moreover, phylogenetic analyses revealed that their homologs co‐exist in galloylated flavan‐3‐ol‐ or hydrolyzable tannin‐rich plant species. Enzymatic assays further revealed the necessity of co‐expression of those homologs for acyltransferase activity. Evolution analysis revealed that the mutations of the CsSCPL5 catalytic residues may have taken place about 10 million years ago. These findings show that the co‐expression of SCPL‐ATs and their NCCPs contributes to the acylation of flavan‐3‐ols in the plant kingdom.

Bacterioplankton Community Profiling of the Surface Waters of Kuwait

The marine waters of Kuwait are highly dynamic and strongly influenced by extreme environmental conditions and high levels of anthropogenic activities. This study explored the bacterioplankton community composition and diversity in Kuwait Bay and at four offshore sites close to urbanized coastal areas during two seasons, autumn (October) and spring (April). 16S rRNA amplicon sequencing detected higher bacterial diversity and richness in spring than in autumn. Also, bacterial community beta diversity revealed a significant seasonal partitioning between the two sampling periods but no clear spatial variation could be depicted. Alphaproteobacteria, Gammaproteobacteria, Cyanobacteria, Flavobacteriia, and Acidimicrobiia dominated the seasonal samples, and SARII clade Ia, SARII clade II, Synechococcus, and SUP05 cluster were among the most abundant taxa in the seasonal samples. However, the strong temporal shift in bacterial community composition was related to Synechococcus abundance. The prevailing physicochemical parameters displayed a significant influence on the bacterioplankton community composition, which was mainly driven by shifts in temperature and nutrient inputs. Furthermore, functional prediction by PICRUSt analysis revealed a relatively stable conserved functional profile in Kuwait’s waters. However, functional genes related to membrane transport were enriched in eutrophic spring waters, while photosynthetic genes were enriched in autumn. Our results provide in-depth insights into the temporal and spatial variations of bacterioplankton dynamics in Kuwait waters and highlight the strong seasonal influence of natural and anthropogenic stressors on their composition and predicted functional capabilities.

Blooms of the harmful algae Margalefidinium polykrikoides and Alexandrium monilatum alter the York River Estuary microbiome

Harmful algal blooms (HABs) cause damage to fisheries, aquaculture, and human health around the globe. However, the impact of HABs on water column microbiomes and biogeochemistry is poorly understood. This study examined the impacts of consecutive blooms of the ichthyotoxic dinoflagellates Margalefidinium polykrikoides and Alexandrium monilatum on the water microbiome in the York River Estuary, Chesapeake Bay, USA. The samples dominated by single dinoflagellate species and by a mix of the two dinoflagellates had different microbiome compositions than the ones with low levels of both species. The M. polykrikoides bloom was co-dominated by Winogradskyella and had increased concentrations of dissolved organic carbon. The A. monilatum bloom had little impact on the prokaryotic portion of the whole community but was associated with a specific group of prokaryotes in the particle-attached (>3 µm) fraction including Candidatus Nitrosopumilus, Candidatus Actinomarina, SAR11 Clade Ia, Candidatus Bealeia, and Rhodobacteraceae HIMB11. Thus, blooms of these two algal species impacted the estuarine microbiome in different ways, likely leading to shifts in estuarine carbon and nutrient cycling, with M. polykrikoides potentially having a greater impact on carbon cycling in the estuarine ecosystem than A. monilatum.

1000. Serotype 3 pneumococci evade activation of the classical complement pathway

BackgroundComplement classical pathway (CCP) activation is the major mechanism leading to opsonophagocytic pneumococcal killing. Following immunization with 13-valent pneumococcal conjugate vaccine (PCV13), opsonophagocytic titers are lowest against serotype 3 among the 13 vaccine serotypes. Post licensure surveillance indicated early declines in serotype 3 invasive pneumococcal disease (IPD) were not sustained over time MethodsUsing flow cytometry, we measured C3 and C4 deposition on serotype 3 strains from children with IPD or nasopharyngeal [NP] carriage, and analyzed by clade. C4 deposition is an indicator of CCP, while C3 deposition is common to all complement pathways. We measured C3/C4 deposition on serotype 3 pneumococcal strains incubated with antibody depleted complement alone or with complement and the following antibodies: mouse monoclonal anti-capsular IgG or IgM, rabbit polyclonal serotype 3 antisera (IgG + IgM) [RPS3A] and RPS3A combined with anti-rabbit IgM, which blocks IgM function, leaving only polyclonal IgGResultsSerotype 3 strains demonstrated high variability in C3 binding when incubated with complement alone. RPS3A (containing both IgM+IgG) and monoclonal IgM activated CCP in all strains. Anti- serotype 3 monoclonal IgG and polyclonal IgG demonstrated absent or limited CCP activation; but activated alternative pathway in some strains. When analyzing complement deposition by clade, a lower proportion of clade II NP serotype 3 strains bound C3 when incubated with complement or monoclonal IgG, compared to clade Ia NP strains. Differences between clade Ia and II IPD strains were not apparent. ConclusionSerotype 3 strains did not demonstrate activation of the CCP in the presence IgG and varied in C3 deposition. Pneumococcal strains that evade CCP activation may be less sensitive to opsonophagocytosis. Our findings suggest a mechanism by which serotype 3 carriage and disease may persist despite immunization with conjugate vaccine containing serotype 3 polysaccharide.Disclosures Rotem Lapidot, MD MSCI, Pfizer (Consultant, Grant/Research Support, Advisor or Review Panel member) Mario Ramirez, PhD, GlaxoSmithKline (Advisor or Review Panel member)Merck Sharp & Dohme (Advisor or Review Panel member)Pfizer (Speaker’s Bureau) Ingrid L. Scully, PhD, Pfizer (Employee, Shareholder) Bradford D. Gessner, MD, MPH, Pfizer Inc. (Employee) stephen pelton, MD, Merck Vaccines (Advisor or Review Panel member, Research Grant or Support)Pfizer, Inc. (Consultant, Advisor or Review Panel member, Research Grant or Support)Sanofi pasteur (Advisor or Review Panel member, Research Grant or Support, DSMB)Seqirus (Consultant)

Accumulibacter diversity at the sub-clade level impacts enhanced biological phosphorus removal performance

Accumulibacter is a well-known group of organisms, typically considered to be polyphosphate accumulating organisms (PAOs), but potentially capable of glycogen accumulating organism (GAO) metabolism under limiting influent phosphate levels. Metabolic features of Accumulibacter are typically linked to its phylogenetic identity at the Type or clade level, though it is unclear the extent to which Accumulibacter diversity can correlate with its capacity to perform P removal. This paper investigates the fine-scale diversity of Accumulibacter and its link with enhanced biological phosphorus removal (EBPR) performance under various operating conditions, to understand the conditions and community structure leading to successful and unsuccessful EBPR operation. For this purpose, the organic carbon feeding rate and total organic carbon concentration were varied during three distinct operational periods, where influent phosphate was never limiting. Accumulibacter was always the dominant microbial group (>80% of all bacteria according to quantitative fluorescence in situ hybridisation - FISH) and low levels of Competibacter and other GAOs were consistently observed (<15% of all bacteria). Steady state was achieved in each of the three periods, with average phosphorus removal levels of 36%, 99% and >99%, respectively. Experimentally determined stoichiometric activity supported the expression of a mixed PAO/GAO metabolism in the first steady state period and the typical PAO metabolism in the other two steady state periods. FISH quantification and amplicon sequencing of the polyphosphate kinase (ppk1) functional gene indicated that Accumulibacter clade IIC was selected in the first steady state period, which shifted to clade IA after decreasing the carbon feeding rate in steady state period 2, and finally shifted back to clade IIC in the third steady state period. Fine-resolution Ppk-based phylogenetic analysis revealed three different clusters within Accumulibacter clade IIC, where clusters IICii and IICiii were linked to poor EBPR performance in period 1, and cluster IICi was linked to good EBPR performance in period 3. This study shows that the deterioration of EBPR processes through GAO activity at non-limiting P concentrations can be linked to organisms that are typically classified as PAOs, not only to known GAOs such as Competibacter. Intra-clade phylogenetic diversity within Accumulibacter showed that some clusters actually behave similarly to GAOs even without influent phosphate limitation. This study highlights the need to closely re-examine traditional interpretations regarding the link between the microbial community composition and identity with the performance and metabolism of EBPR systems.

Terrestrial Inputs Shape Coastal Bacterial and Archaeal Communities in a High Arctic Fjord (Isfjorden, Svalbard).

The Arctic is experiencing dramatic changes including increases in precipitation, glacial melt, and permafrost thaw, resulting in increasing freshwater runoff to coastal waters. During the melt season, terrestrial runoff delivers carbon- and nutrient-rich freshwater to Arctic coastal waters, with unknown consequences for the microbial communities that play a key role in determining the cycling and fate of terrestrial matter at the land-ocean interface. To determine the impacts of runoff on coastal microbial (bacteria and archaea) communities, we investigated changes in pelagic microbial community structure between the early (June) and late (August) melt season in 2018 in the Isfjorden system (Svalbard). Amplicon sequences of the 16S rRNA gene were generated from water column, river and sediment samples collected in Isfjorden along fjord transects from shallow river estuaries and glacier fronts to the outer fjord. Community shifts were investigated in relation to environmental gradients, and compared to river and marine sediment microbial communities. We identified strong temporal and spatial reorganizations in the structure and composition of microbial communities during the summer months in relation to environmental conditions. Microbial diversity patterns highlighted a reorganization from rich communities in June toward more even and less rich communities in August. In June, waters enriched in dissolved organic carbon (DOC) provided a niche for copiotrophic taxa including Sulfitobacter and Octadecabacter. In August, lower DOC concentrations and Atlantic water inflow coincided with a shift toward more cosmopolitan taxa usually associated with summer stratified periods (e.g., SAR11 Clade Ia), and prevalent oligotrophic marine clades (OM60, SAR92). Higher riverine inputs of dissolved inorganic nutrients and suspended particulate matter also contributed to spatial reorganizations of communities in August. Sentinel taxa of this late summer fjord environment included taxa from the class Verrucomicrobiae (Roseibacillus, Luteolibacter), potentially indicative of a higher fraction of particle-attached bacteria. This study highlights the ecological relevance of terrestrial runoff for Arctic coastal microbial communities and how its impacts on biogeochemical conditions may make these communities susceptible to climate change.

Prokaryotic Diversity and Distribution Along Physical and Nutrient Gradients in the Tunisian Coastal Waters (South Mediterranean Sea).

Prokaryotes play an important role in biogeochemical cycling in marine ecosystems, but little is known about their diversity and composition, and how they may contribute to the ecological functioning of coastal areas in the South Mediterranean Sea. This study investigated bacterial and archaeal community diversity in seawater samples along the Tunisian coast subject to important physicochemical disturbances. The 16S amplicon sequencing survey revealed higher prokaryotic diversity in the northern Tunisian bays than in southeastern waters (Gulf of Gabès). The major taxonomic groups identified in all samples were Alphaproteobacteria (40.9%), Gammaproteobacteria (18.7%), Marine Group II Euryarchaeota (11.3%), and Cyanobacteria (10.9%). Among them, the relative abundance of Alteromonadales, Prochlorococcus, and some clades of Pelagibacterales (SAR11) significantly differed between the northern and the southern bays, whereas no difference was observed across coastal waters in the archaeal Candidatus Poseidoniales (MGII), Synechococcus, and Pelagibacteraceae (SAR11 clade Ia), for which no relationship was observed with the environmental variables. Both Pseudoalteromonas and Alteromonas levels increased with the increasing salinity, density and nutrients (NH4+ and/or PO43–) gradients detected toward the southern waters, while the SAR11 clades Ib and IV and Prochlorococcus, decreased in the shallow, salty and nutrient-rich coastal waters of the Gulf of Gabès. Rhodobacteraceae was positively correlated with Synechococcus and chlorophyll levels, suggesting a relationship with phytoplankton biomass. The present study provides the first insights into planktonic prokaryotic community composition in the South Mediterranean Sea through the analysis of Tunisian seawaters, which may support further investigations on the role of bacterioplankton in the biogeochemistry of these ecosystems.

Influence of the cold bottom water on taxonomic and functional composition and complexity of microbial communities in the southern Yellow Sea during the summer

The formation and presence of the cold bottom water (Yellow Sea Cold Water Mass, YSCWM) is a striking hydrological phenomenon in the southern Yellow Sea during the summer and has important effects on the marine ecosystem. To better understand its influence on microbial community structure and function, we compared the bacterial, archaeal and microeukaryotic communities in the cold water mass area (CWMA) and the southern area (SA) during the summer using amplicon and metagenomic sequencings. The habitat environment in the deep waters of the CWMA was characterized by higher salinity/DO/PO4-P, greater depth/distance to the coast, and lower levels of temperature/chlorophyll a/DIN/SiO3-Si/N:P ratio compared to that of the SA. Pure depth or distance to the coast explained a small portion of the microbial community variance, while environment explained a significant fraction of the variance when partialling the effects of depth and distance to the coast. Oligotrophic taxa (e.g. SAR11 clade Ia, Nitrosopumilus, Chloropicophyceae) dominated the deep water communities in the CWMA, while the common coastal taxa (e.g. Roseobacter strain HIMB11, Bacillariophyta, Noctilucophyceae) were more dominant in the deep waters of the SA, suggesting the great impact of the oligotrophic condition in the YSCWM on microbial communities. The microbial co-occurrence networks in the CWMA were less complex but contained a higher proportion of mutual exclusion relationship among prokaryotes; the prokaryotic α-diversity in the CWMA was significantly lower than in the SA while the microeukaryotic α-diversity was significantly higher in the CWMA, implying that prokaryotes and microeukaryotes respond to the cold water mass differently and the competition among prokaryotes was intensified under the impact of the YSCWM. Genes that relate to replication and repair accounted for a significantly lower proportion in the CWMA, which was likely an adaptation to the low carbon environment.

P.080 A translational Homer 1a-based network approach: imaging how haloperidol modulates glutamate system functional connectivity

The dynamic response mechanism of Candidatus Accumulibacter clades to environmental factors in enhanced biological phosphorus removal (EBPR) was unclear. This study investigated the relationship between the transcriptional responses of Candidatus Accumulibacter clades and environmental dynamics. Results suggested that Candidatus Accumulibacter clade IIA only responded in initial 20 and 30 min of P-release and P-uptake stage, respectively, and was also the first clade to stop responding among the six Candidatus Accumulibacter clades. Clade IIC and IID responded at rising stage of P-release and P-uptake rate. Clade IA and IIB responded at decreasing stage of P-release and P-uptake rate. The transcriptional response duration of clade IIF was the longest, which constantly responded throughout anaerobic, anoxic and oxic phase. The transcriptional responses of Candidatus Accumulibacter clades to environmental dynamics revealed the microorganisms actually working in P-release and P-uptake, and gave a new insight into the transcriptional responses related to the EBPR performance.

Pushing the limits of solids retention time for enhanced biological phosphorus removal: process characteristics and Accumulibacter population structure.

Reducing the solids retention time (SRT) of the enhanced biological phosphorus removal (EBPR) process can increase organic carbon diversion to the sidestream for energy recovery, thereby realizing some of the benefits of the high rate activated sludge (HRAS) process. Determining the washout (i.e. minimum) SRT of polyphosphate accumulating organisms (PAOs), therefore, allows for simultaneous phosphorus and carbon diversion for energy recovery from EBPR systems. However, few studies have investigated the washout SRT of PAOs in real wastewater, and little is known of the diversity of PAOs in high rate EBPR systems. Here we demonstrate efficient phosphorus removal (83% orthophosphate removal) in a high rate EBPR sequencing batch reactor fed real primary effluent and operated at 20 °C. Stable operation was achieved at a total SRT of 1.8 ± 0.2 days and hydraulic retention time of 3.7-4.8 hours. 16S rRNA gene sequencing data demonstrated that Accumulibacter were the dominant PAO throughout the study, with a washout aerobic SRT between 0.8 and 1.4 days. qPCR targeting the polyphosphate kinase gene revealed that Accumulibacter clades IIA, IIB and IID dominated the PAO community at low SRT operation, while clade IA was washed out at the lowest SRT values.

Genome-Wide Analysis of Serine Carboxypeptidase-Like Acyltransferase Gene Family for Evolution and Characterization of Enzymes Involved in the Biosynthesis of Galloylated Catechins in the Tea Plant (Camellia sinensis).

Tea (Camellia sinensis L.) leaves synthesize and concentrate a vast array of galloylated catechins (e.g., EGCG and ECG) and non-galloylated catechins (e.g., EGC, catechin, and epicatechin), together constituting 8%–24% of the dry leaf mass. Galloylated catechins account for a major portion of soluble catechins in tea leaves (up to 75%) and make a major contribution to the astringency and bitter taste of the green tea, and their pharmacological activity for human health. However, the catechin galloylation mechanism in tea plants is largely unknown at molecular levels. Previous studies indicated that glucosyltransferases and serine carboxypeptidase-like acyltransferases (SCPL) might be involved in the process. However, details about the roles of SCPLs in the biosynthesis of galloylated catechins remain to be elucidated. Here, we performed the genome-wide identification of SCPL genes in the tea plant genome. Several SCPLs were grouped into clade IA, which encompasses previously characterized SCPL-IA enzymes with an acylation function. Twenty-eight tea genes in this clade were differentially expressed in young leaves and vegetative buds. We characterized three SCPL-IA enzymes (CsSCPL11-IA, CsSCPL13-IA, CsSCPL14-IA) with galloylation activity toward epicatechins using recombinant enzymes. Not only the expression levels of these SCPLIA genes coincide with the accumulation of galloylated catechins in tea plants, but their recombinant enzymes also displayed β-glucogallin:catechin galloyl acyltransferase activity. These findings provide the first insights into the identities of genes encoding glucogallin:catechin galloyl acyltransferases with an active role in the biosynthesis of galloylated catechins in tea plants.

Transcriptional responses of Candidatus Accumulibacter clades to environmental dynamics in enhanced biological phosphorus removal

The dynamic response mechanism of Candidatus Accumulibacter clades to environmental factors in enhanced biological phosphorus removal (EBPR) was unclear. This study investigated the relationship between the transcriptional responses of Candidatus Accumulibacter clades and environmental dynamics. Results suggested that Candidatus Accumulibacter clade IIA only responded in initial 20 and 30 min of P-release and P-uptake stage, respectively, and was also the first clade to stop responding among the six Candidatus Accumulibacter clades. Clade IIC and IID responded at rising stage of P-release and P-uptake rate. Clade IA and IIB responded at decreasing stage of P-release and P-uptake rate. The transcriptional response duration of clade IIF was the longest, which constantly responded throughout anaerobic, anoxic and oxic phase. The transcriptional responses of Candidatus Accumulibacter clades to environmental dynamics revealed the microorganisms actually working in P-release and P-uptake, and gave a new insight into the transcriptional responses related to the EBPR performance.