Distinct Species Research Articles

MARC1 in MASLD: Modulation of lipid accumulation in human hepatocytes and adipocytes.

Mutations in the gene MTARC1 (mitochondrial amidoxime-reducing component 1) protect carriers from metabolic dysfunction-associated steatohepatitis (MASH) and cirrhosis. MTARC1 encodes the mARC1 enzyme, which is localized to the mitochondria and has no known MASH-relevant molecular function. Our studies aimed to expand on the published human genetic mARC1 data and to observe the molecular effects of mARC1 modulation in preclinical MASH models. We identified a novel human structural variant deletion in MTARC1, which is associated with various biomarkers of liver health, including alanine aminotransferase levels. Phenome-wide Mendelian Randomization analyses additionally identified novel putatively causal associations between MTARC1 expression, and esophageal varices and cardiorespiratory traits. We observed that protective MTARC1 variants decreased protein accumulation in in vitro overexpression systems and used genetic tools to study mARC1 depletion in relevant human and mouse systems. Hepatocyte mARC1 knockdown in murine MASH models reduced body weight, liver steatosis, oxidative stress, cell death, and fibrogenesis markers. mARC1 siRNA treatment and overexpression modulated lipid accumulation and cell death consistently in primary human hepatocytes, hepatocyte cell lines, and primary human adipocytes. mARC1 depletion affected the accumulation of distinct lipid species and the expression of inflammatory and mitochondrial pathway genes/proteins in both in vitro and in vivo models. Depleting hepatocyte mARC1 improved metabolic dysfunction-associated steatotic liver disease-related outcomes. Given the functional role of mARC1 in human adipocyte lipid accumulation, systemic targeting of mARC1 should be considered when designing mARC1 therapies. Our data point to plasma lipid biomarkers predictive of mARC1 abundance, such as Ceramide 22:1. We propose future areas of study to describe the precise molecular function of mARC1, including lipid trafficking and subcellular location within or around the mitochondria and endoplasmic reticulum.

Orthology and Paralogy Relationships at Transcript Level.

Eukaryotic genes undergo a mechanism called alternative processing, resulting in transcriptome diversity by allowing the production of multiple distinct transcripts from a gene. More than half of human genes are affected, and the resulting transcripts are highly conserved among orthologous genes of distinct species. In this work, we present the definition of orthology and paralogy between transcripts of homologous genes, together with an algorithm to compute clusters of conserved orthologous and paralogous transcripts. Gene-level homology relationships are utilized to define various types of homology relationships between transcripts originating from the same ancestral transcript. A Reciprocal Best Hits approach is employed to infer clusters of isoorthologous and recent paralogous transcripts. We applied this method to transcripts from simulated gene families as well as real gene families from the Ensembl-Compara database. The results are consistent with those from previous studies that compared orthologous gene transcripts. Furthermore, our findings provide evidence that searching for conserved transcripts between homologous genes, beyond the scope of orthologous genes, is likely to yield valuable information.

A new cryptic species of Polybiidae (Crustacea: Decapoda: Portunoidea) from the East Atlantic, with considerations on the genus Polybius

The use of integrative taxonomy has confirmed the existence of a new distinct crab species, cryptic, within the group of the former genus Liocarcinus, now Polybius, closely related to P. holsatus, P. vernalis and P. marmoreus. Previous reports have considered it to be the Atlantic form of P. vernalis, or as a species “affinis” or “comparable to” P. holsatus. Diagnostic morphological characters are presented for identification and the morphological variability in these species, mainly within P. vernalis (the most related) is analysed. Furthermore, based on molecular and other previous data, a new combination (genus change) is proposed. This new species, Polybius dioscurus sp. nov., lives on infralittoral sandy bottoms, coexisting with the other species mentioned, in the temperate and subtropical zone of the North Atlantic Ocean, including the Alboran Sea (westernmost Mediterranean).

Morphological and genetic data challenge species and subspecies in the Lerista microtis group (Squamata: Scincidae)

The subspecies rank has been widely applied by taxonomists to capture infraspecific variation within the Linnaean classification system. Many subspecies described throughout the 20th century were recognised largely based on perceived variation in single morphological characters yet have since been found not to correspond to separately evolving population lineages, thus requiring synonymy or elevation to full species under lineage-based views of species. These modern lineage-based taxonomic resolutions have resulted from a combination of new molecular genetic techniques, improved geographical sampling of specimens, and more sophisticated analyses of morphological variation (e.g., statistical assessments rather than solely univariate descriptive ones). Here, we revisit the current taxonomic arrangement of species-level and subspecific taxa in the Lerista microtis (Gray) group, which is distributed along a narrow ~2000 km strip on the southern coast of Australia. From specimens of the L. microtis group, an additional species (Lerista arenicola) and two additional subspecies (L. m. intermedia and L. m. schwaneri) were described. We collected data on mensural, meristic, and colour pattern characters to explore morpho-spatial relationships among these taxa. Although our morphological analyses revealed some distinctiveness among specimens from locations assigned to each taxon, this variation is continuous along Australia’s southern coastline, assuming the form of a geographic cline rather than discrete forms. For many characters, however, spatial patterns were inconsistent with the original descriptions, particularly of the subspecies. Moreover, analysis of genome wide restriction-associated DNA loci revealed multiple instances of paraphyly among taxa, with phylogenetic clustering of specimens assigned to distinct species and subspecies. These emerging patterns provide no support for L. arenicola as a species evolving separately from L. microtis. Additionally, our findings challenge the presumed distinctiveness and coherence of the three subspecies of L. microtis. We thus synonymise L. arenicola and the L. microtis subspecies with L. microtis and provide a redescription of a single yet morphologically variable species—an arrangement that best reflects evolutionary history and the continuous nature of morphological variation across space.

Implications of Climate-Induced Localised Extinction of Bull Kelp (Durvillaea amatheiae) for Holdfast Macrofauna

Globally, work is being undertaken to preserve biodiversity and prevent further species extinctions. Yet, without adequate data about the presence of species within ecosystems, hidden extinctions can occur without our knowledge. Given that poleward range retractions are projected for bull kelp (Durvillaea amatheiae) in southeastern Australia, there is the potential for hidden extinctions to occur in associated macrofaunal species. However, this risk cannot be assessed due to the limited data on the invertebrate macrofauna associated with D. amatheiae. We documented macrofauna within D. amatheiae holdfasts, with the objective of establishing a first analysis of the holdfast fauna for this kelp and identifying, where possible, any host-specific taxa. Holdfasts were collected at six locations, spanning most of the range of D. amatheiae on the southeastern Australian mainland. Macrofauna were removed from holdfasts and identified to the lowest possible taxonomic level. Modelling was applied to determine factors correlated with patterns of assemblages among locations. Holdfast assemblages were found to vary significantly among locations and exhibited a latitudinal gradient in assemblage structure. The northernmost location (Aragunnu), which has the highest risk of D. amatheiae range retractions, was found to have distinct species assemblages and generally higher diversity and abundance than locations further south. However, no host-specific taxa were identified in samples, indicating that there is a low risk of multiple hidden species extinctions occurring in holdfast macrofauna, due to future range retractions of D. amatheiae. Rather, most of the macrofauna taxa in D. amatheiae holdfasts were found to also occur in association with the sympatric golden kelp Ecklonia radiata, which is not expected to undergo range retractions at the latitudes where losses of D. amatheiae are projected. Overall, there is an urgent need to develop strategies to combat projected future range retractions of D. amatheiae to reduce impacts on the species that rely on D. amatheiae for habitat.

Integrative physiology and transcriptome reveal salt-tolerance differences between two licorice species: Ion transport, Casparian strip formation and flavonoids biosynthesis

BackgroundGlycyrrhiza inflata Bat. and Glycyrrhiza uralensis Fisch. are both original plants of ‘Gan Cao’ in the Chinese Pharmacopoeia, and G. uralensis is currently the mainstream variety of licorice and has a long history of use in traditional Chinese medicine. Both of these species have shown some degree of tolerance to salinity, G. inflata exhibits higher salt tolerance than G. uralensis and can grow on saline meadow soils and crusty saline soils. However, the regulatory mechanism responsible for the differences in salt tolerance between different licorice species is unclear. Due to land area-related limitations, the excavation and cultivation of licorice varieties in saline-alkaline areas that both exhibit tolerance to salt and contain highly efficient active substances are needed. The systematic identification of the key genes and pathways associated with the differences in salt tolerance between these two licorice species will be beneficial for cultivating high-quality salt-tolerant licorice G. uralensis plant varieties and for the long-term development of the licorice industry. In this research, the differences in growth response indicators, ion accumulation, and transcription expression between the two licorice species were analyzed.ResultsThis research included a comprehensive comparison of growth response indicators, including biomass, malondialdehyde (MDA) levels, and total flavonoids content, between two distinct licorice species and an analysis of their ion content and transcriptome expression. In contrast to the result found for G. uralensis, the salt treatment of G. inflata ensured the stable accumulation of biomass and total flavonoids at 0.5 d, 15 d, and 30 d and the restriction of Na+ to the roots while allowing for more K+ and Ca2+ accumulation. Notably, despite the increase in the Na+ concentration in the roots, the MDA concentration remained low. Transcriptome analysis revealed that the regulatory effects of growth and ion transport on the two licorice species were strongly correlated with the following pathways and relevant DEGs: the TCA cycle, the pentose phosphate pathway, and the photosynthetic carbon fixation pathway involved in carbon metabolism; Casparian strip formation (lignin oxidation and translocation, suberin formation) in response to Na+; K+ and Ca2+ translocation, organic solute synthesis (arginine, polyamines, GABA) in response to osmotic stresses; and the biosynthesis of the nonenzymatic antioxidants carotenoids and flavonoids in response to antioxidant stress. Furthermore, the differential expression of the DEGs related to ABA signaling in hormone transduction and the regulation of transcription factors such as the HSF and GRAS families may be associated with the remarkable salt tolerance of G. inflata.ConclusionCompared with G. uralensis, G. inflata exhibits greater salt tolerance, which is primarily attributable to factors related to carbon metabolism, endodermal barrier formation and development, K+ and Ca2+ transport, biosynthesis of carotenoids and flavonoids, and regulation of signal transduction pathways and salt-responsive transcription factors. The formation of the Casparian strip, especially the transport and oxidation of lignin precursors, is likely the primary reason for the markedly higher amount of Na+ in the roots of G. inflata than in those of G. uralensis. The tendency of G. inflata to maintain low MDA levels in its roots under such conditions is closely related to the biosynthesis of flavonoids and carotenoids and the maintenance of the osmotic balance in roots by the absorption of more K+ and Ca2+ to meet growth needs. These findings may provide new insights for developing and cultivating G. uralensis plant species selected for cultivation in saline environments or soils managed through agronomic practices that involve the use of water with a high salt content.

Caproicibacter sp. BJN0012, a potential new species isolated from cellar mud for caproic acid production from glucose

Acids play a crucial role in enhancing the flavor of strong-aroma Baijiu, and among them, caproic acid holds significant importance in determining the flavor of the final product. However, the metabolic synthesis of caproic acid during the production process of Baijiu has received limited attention, resulting in fluctuations in caproic acid content among fermentation batches and generating production instability. Acid-producing bacteria found in the cellar mud are the primary microorganisms responsible for caproic acid synthesis, but there is a lack of research on the related microbial resources and their metabolic properties. Therefore, it is essential to identify and investigate these acid-producing microorganisms from cellar mud to ensure stable caproic acid synthesis. In this study, a unique strain was isolated from the cellar mud, exhibiting a 98.12% similarity in its 16S rRNA sequence and an average nucleotide identity of 79.57% with the reference specie, together with the DNA-DNA hybridization of 23.20% similarity, confirming the distinct species boundaries. The strain was able to produce 1.22 ± 0.55g/L caproic acid from glucose. Through genome sequencing, annotation, and bioinformatics analysis, the complete pathway of caproic acid synthesis from glucose was elucidated, and the catalytic mechanism of the key thiolase for caproic acid synthesis was investigated. These findings provide useful fundamental data for revealing the metabolic properties of caproic acid-producing bacteria found in cellar mud.

An integrative taxonomic study of north temperate Cotesia Cameron (Hymenoptera, Braconidae, Microgastrinae) that form silken cocoon balls, with the description of a new species

Using CO1 sequence analysis, we investigated the relationships of Western Palearctic and Nearctic Cotesia that spin aggregated cocoons in the shape of a ball, and as adults are morphologically very similar. The analysis included the conceptual taxa C. tibialis, C. ofella, C. vanessae, C. ruficrus, C. xylina and C. yakutatensis, as well as the newly described species C. trivaliaesp. nov. The examined specimens of C. tibialis, C. ofella, C. vanessae, C. ruficrus and C. trivaliaesp. nov. were collected in several European countries, and C. xylina and C. yakutatensis in Canada and the USA. Molecular analyses showed that C. ruficrus is not closely related to the other studied taxa. Based on the genetic distances as well as biology and morphology, C. vanessae and C. ofella are confirmed as solid taxa. The species C. yakutatensis comprises two entities. Having 8 haplotypes, C. tibialis also emerges as a species complex, divided into two clusters. With 26 detected haplotypes, C. xylina shows the highest diversity, being composed of three segregates. The conceptual species C. tibialis, C. xylina and C. yakutatensis seem to be species complexes containing several candidates for recognition as distinct species. One from the European C. tibialis complex is here described as new, and the impediments to be overcome before the description of further species are outlined.

Genome-Wide Identification and Expression Analysis of TGA Family Genes Associated with Abiotic Stress in Sunflowers (Helianthus annuus L.).

Sunflower (Helianthus annuus L.) is an important, substantial global oil crop with robust resilience to drought and salt stresses. The TGA (TGACG motif-binding factor) transcription factors, belonging to the basic region leucine zipper (bZIP) family, have been implicated in orchestrating multiple biological processes. Despite their functional significance, a comprehensive investigation of the TGA family's abiotic stress tolerance in sunflowers remains elusive. In the present study, we identified 14 TGA proteins in the sunflower genome, which were unequally distributed across 17 chromosomes. Employing phylogenetic analysis encompassing 149 TGA members among 13 distinct species, we revealed the evolutionary conservation of TGA proteins across the plant kingdom. Collinearity analysis suggested that both HaTGA01 and HaTGA03 were generated due to HaTGA08 gene duplication. Notably, qRT-PCR analysis demonstrated that HaTGA04, HaTGA05, and HaTGA14 genes were remarkably upregulated under ABA, MeJA, and salt treatments, whereas HaTGA03, HaTGA06, and HaTGA07 were significantly repressed. This study contributes valuable perspectives on the potential roles of the HaTGA gene family under various stress conditions in sunflowers, thereby enhancing our understanding of TGA gene family dynamics and function within this agriculturally significant species.

A new sympagic nematode species Daptonema gelida sp. n. (Monhysterida, Xyalidae) from the White Sea landfast ice

A new ice-associated species of Xyalidae family, Daptonema gelida sp. n., is described from the first-year fast sea ice of the Ermolinskaya Inlet, White Sea, Russia. The new species of Daptonema is a morphologically distinct species from other species of the genus. Daptonema gelida sp. n. is characterized by (1) elongated, slender body, (2) short, evenly distributed throughout the body somatic setae, (3) circular amphideal fovea, (4) thin and strongly curved, L-shaped spicules with round-shaped manubrium, (5) gubernaculum with short dorsal-caudal apophysis by triangular-shaped outline, (6) post-vulval uterine sac present, and (7) two short terminal setae. We barcoded partial 18S rRNA gene sequences from the new sympagic species. Phylogenetic reconstructions showed that the specimen of Daptonema gelida sp. n. formed a distinct lineage with high support among other Daptonema species and was genetically related to D. carnulentum, D. setosum, D. hirsutum, Metadesmolaimus sp. and Daptonema spp. We provided a list of valid Daptonema species, including key morphological characteristics of males, and additionally reviewed 30 species inquirenda.

Using molecular and morphometric data as operational criteria for the analysis of a threatened rainforest species complex shows interspecific variation, with implications for cryptic-species delimitation and conservation

Resolution of systematic associations and species boundaries is vital for developing conservation priorities for threatened taxa. A complex of Fontainea (Euphorbiaceae) populations, endemic to rainforest communities in central-eastern Australia, comprises several taxonomically challenging species. Fontainea oraria is Critically Endangered, with only one natural population of 10 mature individuals, with the closely related species F. australis being listed as Vulnerable. A recently discovered Fontainea population (currently nominated as F. sp. Coffs Harbour) with taxonomic similarities to F. oraria has been provisionally listed as Critically Endangered, with fewer than 40 individuals. This study employed an integrative approach, combining genetic data and morphometrics to determine species boundaries for three threatened Fontainea population groups as a model system for an integrative approach to delimiting cryptic species. Although our results suggest the potential subdivision of the population groups into three taxa, caution is warranted because this hypothesis remains inconclusive. Taxonomic challenges demand a careful approach, acknowledging the possibility of alternative interpretations. Contrary to supporting distinct species, our morphological and genetic data may also be interpreted as indicative of a single species with geographic variation, a phenomenon observed in genetically linked populations experiencing isolation by distance. Overall, we highlight the need for further research to establish species limits to guide conservation actions.

Marinobacter azerbaijanicus sp. nov., a moderately halophilic bacterium from Urmia Lake, Iran.

A novel moderately halophilic, Gram-stain-negative and facultatively anaerobic bacterium, designated as strain TBZ242T, was isolated from water of Urmia Lake in the Azerbaijan region of Iran. The cells were found to be rod-shaped and motile by a single polar flagellum, producing circular and yellowish colonies. The strain could grow in the presence of 0.5-10 % (w/v) NaCl (optimum, 2.5-5 %). The temperature and pH ranges for growth were 15-45 °C (optimum 30 °C) and pH 7.0-11.0 (optimum pH 8.0) on marine agar. The 16S rRNA gene sequence analysis revealed that strain TBZ242T belonged to the genus Marinobacter, showing the highest similarities to Marinobacter algicola DG893T (98.8 %), Marinobacter vulgaris F01T (98.8 %), Marinobacter salarius R9SW1T (98.5 %), Marinobacter panjinensis PJ-16T (98.4 %), Marinobacter orientalis W62T (98.0 %) and Marinobacter denitrificans JB2H27T (98.0 %). The 16S rRNA and core-genome phylogenetic trees showed that strain TBZ242T formed a distinct branch, closely related to a subclade accommodating M. vulgaris, M. orientalis, M. panjinensis, M. denitrificans, M. algicola, M. salarius and M. iranensis, within the genus Marinobacter. Average nucleotide identity and digital DNA-DNA hybridization values between strain TBZ242T and the type strains of the related species of Marinobacter were ≤85.0 and 28.6 %, respectively, confirming that strain TBZ242T represents a distinct species. The major cellular fatty acids of strain TBZ242T were C16 : 0 and C16 : 1  ω7c/C16 : 1 ω6c and the quinone was ubiquinone Q-9. The genomic DNA G+C content of strain TBZ242T is 57.2 mol%. Based on phenotypic, chemotaxonomic and genomic data, strain TBZ242T represents a novel species within the genus Marinobacter, for which the name Marinobacter azerbaijanicus sp. nov. is proposed. The type strain is TBZ242T (= CECT 30649T = IBRC-M 11466T). Genomic fragment recruitment analysis showed that this species prefers aquatic saline environments with intermediate salinities, being detected on metagenomic databases of Lake Meyghan (Iran) with 5 and 18 % salinity, respectively.

The ICU environment contributes to the endemicity of the "Serratia marcescens complex" in the hospital setting.

Serratia marcescens is an opportunistic pathogen historically associated with sudden outbreaks in intensive care units (ICUs) and the spread of carbapenem-resistant genes. However, the ecology of S. marcescens populations in the hospital ecosystem remains largely unknown. We combined epidemiological information of 1,432 Serratia spp. isolates collected from sinks of a large ICU that underwent demographic and operational changes (2019-2021) and 99 non-redundant outbreak/non-outbreak isolates from the same hospital (2003-2019) with 165 genomic data. These genomes were grouped into clades (1-4) and subclades (A and B) associated with distinct species: Serratia nematodiphila (1A), S. marcescens (1B), Serratia bockelmannii (2A), Serratia ureilytica (2B), S. marcescens/Serratia nevei (3), and S. nevei (4A and 4B). They may be classified into an S. marcescens complex (SMC) due to the similarity between/within subclades (average nucleotide identity >95%-98%), with clades 3 and 4 predominating in our study and publicly available databases. Chromosomal AmpC β-lactamase with unusual basal-like expression and prodigiosin-lacking species contrasted classical features of Serratia. We found persistent and coexisting clones in sinks of subclades 4A (ST92 and ST490) and 4B (ST424), clonally related to outbreak isolates carrying blaVIM-1 or blaOXA-48 on prevalent IncL/pB77-CPsm plasmids from our hospital since 2017. The distribution of SMC populations in ICU sinks and patients reflects how Serratia species acquire, maintain, and enable plasmid evolution in both "source" (permanent, sinks) and "sink" (transient, patients) hospital patches. The results contribute to understanding how water sinks serve as reservoirs of Enterobacterales clones and plasmids that enable the persistence of carbapenemase genes in healthcare settings, potentially leading to outbreaks and/or hospital-acquired infections.IMPORTANCEThe "hospital environment," including sinks and surfaces, is increasingly recognized as a reservoir for bacterial species, clones, and plasmids of high epidemiological concern. Available studies on Serratia epidemiology have focused mainly on outbreaks of multidrug-resistant species, overlooking local longitudinal analyses necessary for understanding the dynamics of opportunistic pathogens and antibiotic-resistant genes within the hospital setting. This long-term genomic comparative analysis of Serratia isolated from the ICU environment with isolates causing nosocomial infections and/or outbreaks within the same hospital revealed the coexistence and persistence of Serratia populations in water reservoirs. Moreover, predominant sink strains may acquire highly conserved and widely distributed plasmids carrying carbapenemase genes, such as the prevalent IncL-pB77-CPsm (pOXA48), persisting in ICU sinks for years. The work highlights the relevance of ICU environmental reservoirs in the endemicity of certain opportunistic pathogens and resistance mechanisms mainly confined to hospitals.

Morphological and molecular characterization of brown-banded broodsacs and metacercariae of Leucochloridium (Trematoda: Leucochloridiidae) parasitizing the semi-slug Omalonyx unguis (Succineidae) in Argentina

Trematodes of the genus Leucochloridium exhibit an unusual transmission strategy among mollusks (intermediate host). The fully developed sporocyst, housing encysted metacercariae, displays vivid coloration and rhythmic activity in the snail's tentacle, mimicking insect larvae. These strategies attract insectivorous birds, their final hosts, thereby increasing the chances of completing their life cycle. In South America, the reports of adults and larval stages of Leucochloridium are scarce. Brown-banded broodsac of Leucochloridium sp. were obtained from Omalonyx unguis collected in a shallow lake from Corrientes Province, Argentina. Here, we morphologically characterized the larval stages (broodsac and metacercaria), identified the parasite through DNA sequences from nuclear 28S-rRNA (28S) and the mitochondrial cytochrome c oxidase I (COI) genes, and explored its evolutionary affinities with the Leucochloridium species available in GenBank. The present broodsac displays brown bands, with a yellowish background in the first two-thirds and yellowish-white in the last third. Based on morphological comparisons, the broodsac and metacercaria described in this study could not be conclusively categorized under any known South American species of Leucochloridium. In relation to the phylogenetic reconstructions, Leucochloridium sp. consistently clustered with L. perturbatum, and species delimitation analyses resulted in recognized Leucochloridium sp. from Argentina as a distinct species. The DNA sequences obtained in this study constitute the first genetic data generated for sporocyst broodsacs in South America. Future studies, incorporating morphology, genetic, and biological data, will be essential for both species identification and the elucidation of leucochloridiid diversity in the region.

‘—and so this tree— / O that such our death may be—’: Shelley’s Last Treescapes

Trees shift between visual, literal, and rhetorical figures in Shelley’s poetry, where distinctive tree species accentuate particular qualities of verse. Attentive to the final year of Shelley’s life, this essay explores the treescapes of the poet’s ultimate work, ‘The Triumph of Life’, and the pine’s suspension of time in Shelley’s last lyrics to Jane Williams: ‘To Jane. The Invitation’, ‘To Jane–The Recollection’, and ‘With a Guitar. To Jane’. The pines that populate the Jane Poems are complicit in the arrestation of the lyrical moment, embalming poetic speaker and subject in deathly amber. In ‘The Triumph of Life’, broadleaved species – the chestnut and the poplar – regenerate the fallen leaves of the ‘Ode to the West Wind’ by sowing the seeds of posterity. Rooted in a tradition of arboreal poetics from the classical world to the contemporary, Shelley’s trees construct an allusive network of intertextual echoes.

Savitreea siamensis sp. nov., an ascomycetous yeast species in the family Saccharomycetaceae discovered in Thailand.

Four yeast strains, representing a novel anamorphic species, were isolated in Thailand. The two strains (ST-3660T and ST-3647) were obtained from two different estuarine water samples in a mangrove forest. Strain DMKU-FW1-37 was derived from a grease sample, and another strain (TSU57) was isolated from a fruiting body of Phallus sp. Pairwise sequence analysis showed that the four strains had identical or differed by only one nucleotide substitution in the D1/D2 domains of the large subunit (LSU) rRNA gene, and differed by one to three nucleotide substitutions in the internal transcribed spacer (ITS) regions. Savitreea pentosicarens is the most closely related species to the four strains, but with 9-10 (1.57-1.72 %) nucleotide substitutions in the D1/D2 domains of the LSU rRNA gene and 29-31 (4.22-4.45 %) nucleotide substitutions in the ITS regions. Phylogenetic analyses based on the concatenated sequences of the ITS regions and the D1/D2 domains of the LSU rRNA gene showed that the four strains form a well-separated lineage from S. pentosicarens with high bootstrap support, confirming that they represent a distinct species. Therefore, the four strains are assigned as representives of a novel species of the genus Savitreea, for which the name Savitreea siamensis sp. nov. is proposed. The holotype is TBRC 4481T and the ex-type is PYCC 9794T (=ST-3660T). The MycoBank number of the novel species is MB 851951.

Carbon pool and respiration of rhizosphere soils of different mangrove plant species in bangladesh sundarbans

Bangladesh Sundarbans like other mangrove ecosystems are vital carbon reservoirs in the global carbon cycle. Soil respiration, a key carbon flux, is closely linked to climate change. Despite extensive research on the Sundarbans, a gap exists in studying rhizosphere soil carbon pool (SOC) and respiration (Rs), which is crucial for understanding its role in global climate dynamics, especially the local climate. This study investigated SOC pools and Rs rates of oligohaline, mesohaline, and polyhaline zones of the Bangladesh Sundarban Mangrove Forests (SMF). The oligohaline zone exhibited the highest average SOC content (11.26 ± 5.52 t/ha), followed by the mesohaline zone (9.91 ± 3.09 t/ha) and the polyhaline zone (9.86 ± 4.16 t/ha). The Rs rate was comparatively higher in the mesohaline zone (28.19 ± 5.02 mg CO2/g soil), followed by the polyhaline zone (27.81 ± 4.38 mg CO2/g soil), and the oligohaline zone (27.63 ± 4.16 mg CO2/g soil) though the differences were not significant. Further analyses explored the influences of plant species on SOC and Rs. While rhizosphere soil of distinct plant species displayed varying SOC values, Rs did not exhibit significant differences among different plant species, and no significant relation was observed between Rs and SOC values. Mangroves were noted to store substantial amounts of organic carbon in their soils, yet they released relatively less carbon dioxide (CO2) through soil respiration compared to other tropical forests. This unique characteristic underscores the critical role of mangroves in global climate change dynamics. Conclusively, this study offers insightful information about the carbon dynamics of the Bangladesh SMF, emphasizing the significance of mangroves as carbon reservoirs with the potential to influence climate change adaptation strategies. Bangladesh J. Bot. 53(1): 131-140, 2024 (March)

Redescription of Pronematus ubiquitus (McGregor, 1932) (Acari, Iolinidae), description of two new species and redescription of two additional species with a review of and key to all Pronematus species

Pronematus ubiquitus (McGregor) is redescribed based on specimens collected at the type locality. Additionally, in a survey for natural enemies of Aculops lycopersici (Tryon), P. ubiquitus was found in most European countries where samples were gathered as well as in Morocco. Together with specimens available from museum collections and originating from Brazil, South Africa and Türkiye, the newly collected specimens were measured and morphologically compared with those from the type locality. Additionally, single female expansion lines were set-up with specimens from California (USA), Belgium, France, Italy, The Netherlands and Morocco, and molecular analysis were performed in order to construct a phylogenetic tree. The tree showed differences between origins, but this was assigned to intraspecific variation. A PCA analysis on morphological characters separated the Brazilian specimens from those of all other geographical origins. The Californian (USA) specimens grouped together, as did the Moroccan and all European specimens, but with overlap between the groups. The Brazilian specimens were described as a new species, P. brasiliensis n. sp. All other specimens were considered as P. ubiquitus. Furthermore, we searched for types of early described Pronematus species and studied P. rykei, P. karrooi and P. tenuisetosus types; the first two species were confirmed morphologically as a distinct Pronematus species while the latter belongs to the genus Pseudopronematulus. The morphological characteristics of specimens that were used for a recent redescription of P. rykei did not coincide with our redescription of the type. We transferred those specimens to the new species, P. juglandi sp. nov.

Microalgae Growth in a Biocathode-Photosynthesis Microbial Desalination Cell: Molecular Characterization, Modeling Study, and Performance Evaluation

This study aimed to comprehensively characterize and identify microalgae inhabiting the biocathode compartment of a photosynthetic microbial desalination cell (PMDC). Also, modeling of microalgae growth in the biocathode was considered as well as the interrelation between the growth of microalgae and dissolved oxygen (DO) generation within the biocathode. The general performance of the PMDC was evaluated based on; (1) organic content removal from the real domestic wastewater fed to the anode compartment, (2) salinity removal from actual seawater in the desalination compartment, and (3) power generation in the PMDC. The results unveiled the presence of two distinct microalgae species, specifically Coelastrella sp. and Mariniradius saccharolyticus, which were thoroughly characterized using 16S rRNA and ITS gene sequencing within the cathodic chamber of the PMDC. Following sequence editing and trimming, the resulting sequences were meticulously submitted to the NCBI GenBank and juxtaposed with other sequences utilizing the GenBank online BLAST software. Importantly, the obtained data demonstrated a good correlation with coefficients of determination (R²) reaching 0.83, as per the employed kinetic models. Complete removal of up to 99.11% of organic content from the real domestic wastewater was obtained in the PMDC system with maximum efficiency of desalination elimination of 80.95% associated with a maximum power output of 420 mW/m3 in the system.

IDENTIFICATION OF MEDICINAL HERBAL PLANT USING CNN

Herbaceous vegetation are critical for life in the world. There are many special sorts of plant life and their variety will increase every 12 months. Knowledge of various species is important in groups such as foresters, farmers, ecologists and educators. Species identification is therefore of intermediate interest. However, this requires professional know-how and may be tough and hard for non-specialists who've very little knowledge of traditional botanical terminology. But advances in device studying and computer vision can help make this assignment exceedingly clean. No system is but advanced enough to pick out all plant species, but a few work has been finished. In any take a look at we've got made such a try. Vegetation identification commonly includes four steps: picture acquisition, preprocessing, function extraction, and segmentation. This take a look at used photos from the Swedish Leaflet dataset, which includes 1125 photos of 15 distinct species. This is accompanied with the aid of preprocessing the usage of a Gaussian filtering engine, and then texture and colour features are extracted. Finally, the category become executed using convolutional neural networks, which accomplished nearly ninety five.26% accuracy, and we purpose for similarly development. Keywords: Identification, medical, Herbal Plant, Species, Machine Learning, Image Processing