The neighbor-joining method: a new method for reconstructing phylogenetic trees

Identification and biodegradation characterization of high-density polyethylene using marine bacteria isolated from the coastal region of the Arabian Sea, at Gujarat, India

High-Density Polyethylene (HDPE) PE is one of the primary contributors of long-lasting and prolonged pollution in the environment. In this study, more than three hundred marine isolates collected off the Gujarat Sea coast were tested for HDPE plastic utilizing ability. Among fifty-one positive noted isolates, RS124 as a potential strain was identified as Micrococcus flavus (accession is PP858228) based on 16 S rRNA gene sequencing and total cellular fatty acid profiling. Initial bacterial adherence on the film surface was shown in a scanning electron microscopy (SEM) image as a key step to biodegradation. Moreover, atomic force microscopy (AFM) shows that the film surface became more fragile, damaged, and rougher than untreated films. Shifts and alterations in peak transmittance with emergence of two new shouldered peak in degraded HDPE observed by fourier transform infrared spectroscopy (FTIR) was associated to chemical and mechanical alteration. Thermogravimetric analysis (TGA) analysis designated larger difference in percent weight loss provisions thermal instability. In the enzymatic study, the highest activity of peroxidase and dehydrogenase was recorded on the 3rd and 4th weeks of treatment with strain, respectively, during co-incubation. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis disclosed the presence of a distinct 19 kDa size protein, uncovering its role in the colonization of bacteria on the hydrophilic HDPE surfaces. About 1.8% weight reduction in HDPE was recorded as a result after 30 days of bio-treatment with M. flavus. Hence, the entire observed results reveal that the M. flavus RS124 could be effectively applied for the degradation of HDPE. This is the first report on M. flavus that it exhibits plastic degrading characteristic ever, which may allow for green scavenging of plastic waste.

Barcode gap delimitation and phylogenetic analyses in integrative earthworm taxonomy: Dendrobaena byblica complex

Dendrobaena byblica (Rosa, 1893) is a species complex consisting of at least 17 nominal taxa and with Circum-Mediterranean distribution. The taxonomic classification of this group based on shape of internal structures and external characteristics indicated that this species complex indeed consists of several clades. More molecular studies are needed to confirm this issue. In this study, samples from the Hyrcanian forests in the north of Iran were studied, which were genetically different from the sequences retrieved from GenBank. The results of the ABGD analyses suggest that the genetic distance for species delimitation in D. byblica is 9%, a much lower value than that reported for other species included in the family Lumbricidae. The range of COI K2p genetic distance between GenBank sequences of Dendrobaena and examined species in the present study, is 12.3-24.6%. Assessing whether these genetic variations correspond to different biological species or correspond to intraspecific phenotypic variability will require further studies using other genetic molecular markers.

Ornithinibacillus xuwenensis sp. nov., A Novel Thermotolerant Bacterium Isolated from Mangrove Sediment

A Gram-stain positive, long-rod-shaped, motile, and aerobic bacterial strain, designated 16A2ET, was isolated from mangrove sediment sample. The 16S rRNA gene sequence similarity analysis indicated that strain 16A2ET exhibited high similarity to Ornithinibacillus contaminans CCUG 53201T (98.2%), Ornithinibacillus bavariensis WSBC 24001T (98.1%), and Ornithinibacillus scapharcae TW25T (97.7%). Strain 16A2ET grew within a temperature range of 20-50 °C (optimum 40 °C), a pH range of 6.0-9.0 (optimum pH 8.0), and in the presence of 0-10% (w/v) NaCl (optimum 1%). The genome size of strain 16A2ET is 3.60 Mbp, with a G + C content of 36.7%. The overall genome related index (OGRI) analyses revealed low average nucleotide identity (ANI < 75.9%), average amino acid identity (AAI < 77.5%), and digital DNA-DNA hybridization (dDDH < 19.8%) with other species in the genus Ornithinibacillus. Chemotaxonomic analyses revealed that the major polar lipids include diphosphatidylglycerol, phosphatidylglycerol, phospholipids, and an aminophospholipid. The predominant fatty acids were iso-C15:0, anteiso-C15:0, and anteiso-C17:0. The sole respiratory quinone was menaquinone-7 (MK-7), and the peptidoglycan amino acid type was determined to be A4β. Based on phenotypic and genotypic analyses, strain 16A2ET (= GDMCC 1.4379T = JCM 36753T) represents a novel species within the genus Ornithinibacillus, for which the name Ornithinibacillus xuwenensis sp. nov. is proposed.

Exploring anticancer, antioxidant, and antimicrobial potential of Aspergillus flavus, a fungal endophyte isolated from Dillenia indica leaf callus

Background

Endophytic fungi represent a compelling assemblage of microorganisms that inhabit plant tissues without inflicting any discernible detriment to the host organism. They foster a symbiotic association with their host plants, frequently conferring advantages such as augmented growth, enhanced resilience to stressors, and safeguarding against pathogens.

Study design

Dillenia indica is a medicinal tree of Dilleniaceae. This study aims to isolate and identify the fungi growing as a contaminant in leaf callus. For the identification, both morphological observation and molecular methods were used. The presence of secondary metabolites in different fungal extracts were observed by FTIR and High-resolution accurate mass spectroscopy (HRAMS) methods. Different biological activities (antioxidant, antibacterial and antitumor) of fungal extracts were assessed.

Methods

For callus initiation, leaf tissues of Dillenia indica were inoculated on Murashige and Skoog's medium supplemented with BAP (1mgl-1) and NAA (1mgl-1) plant growth regulators. To raise pure cultures of endophyte, fungal hyphae were isolated from the contaminated cultures and were grown on Potato Dextrose Agar medium. For molecular identification, genomic DNA (gDNA) was isolated from fungal mycelia. Internal transcribed spacers (ITS1 and ITS4) were used to amplify the conserved ITS region of the fungal gDNA. Previously deposited sequences in the Gene bank were used for the identification and making of phylogenetic tree. Antioxidant, antibacterial and anticancer potential of fungal extracts were studied.

Results

The endophyte was identified as Aspergillus flavus. FTIR study showed the presence of diverse types of secondary metabolites in fungal extract. A significant presence of phenolics, flavonoids, terpenes, steroids, etc. was observed by High-resolution accurate mass spectroscopy analysis (HRAMS) of fungal extract. Endophyte extract prepared in chloroform showed both antioxidant (IC50 430.23) and antibacterial (maximum inhibition of E. coli:15 ± 0.62 mm) potential compared to other solvents. Cell viability decreased at high concentrations of endophyte extract prepared in chloroform and ethyl acetate solvents. Fungal extract prepared in ethyl acetate showed considerable cytotoxicity and growth inhibition of DL tumor cells.

Conclusion

In the present study, isolated endophyte of Dillenia indica showed high occurrence of secondary metabolites. Fungal extracts showed antioxidant, antibacterial and antitumor activities. As, endophytes are remarkable source of active constituents, there is a great need to explore such endophytes. Their extensive studies are required to develop an alternative of plant less production of valuable compounds.

Comparative Genomic Analysis of 66 Bacteriophages Infecting Morganella morganii Strains

Bacteriophages are viruses that specifically target bacteria and play a crucial role in influencing bacterial evolution and the transmission of antibiotic resistance. In this study, we explored the genomic profiles of 66 bacteriophages that infect Morganella morganii, an opportunistic pathogen associated with difficult-to-treat nosocomial and urinary tract infections. Our findings highlight the extraordinary diversity within this phage population, reflected in their genomic features, evolutionary relationships, and potential contributions to bacterial pathogenicity. The 66 phage genomes exhibited diversity in size, spanning from 6 to 115 kilobase pairs, reflecting a heterogeneous genetic material and coding potential. Their guanine-cytosine (G+C) content varied widely, from 43.3% to 64.6%, suggesting diverse evolutionary origins and adaptive strategies. Phylogenetic analysis identified ten distinct evolutionary clusters, some classified as singletons, highlighting unique evolutionary pathways. Several clusters included phages capable of infecting multiple M. morganii strains, indicating a broader host range and the potential for horizontal gene transfer. Genomic analysis also determined a substantial number of hypothetical proteins, underscoring the need for further investigation to clarify their functions. Importantly, we identified a wide array of antibiotic resistance and virulence-associated genes within these phage genomes, illuminating their potential to impact the treatment of M. morganii infections and develop new, more virulent strains. These findings highlight the critical role of phage-mediated gene transfer in shaping bacterial evolution and facilitating the transmission of antibiotic resistance.

Antagonistic activity of butanamine 2,2-dinitro-N-methyl- synthesized by endosymbiotic Bacillus amyloliquefaciens VITAPRJS1 acquired from horse milk

Endosymbiotic bacteria are known to synthesize bioactive compounds which have biotechnological potentials that enhance immune responses by stimulating the production of immune cells. Horse milk is widely known to have nutraceutical and antimicrobial activities; however, there are no scientific reports on its inhibitory effects. VITAPRJS1, isolated from horse milk, showed non-hemolytic properties and was significantly tolerant to bile salt and NaCl. The isolate also exhibited potent antibacterial activity against pathogenic bacterial strains such as Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Bacillus cereus. The bioactive antibacterial compounds were extracted using dichloromethane and were subsequently purified and identified as butanamine, 2,2-dinitro-N-methyl- through UPLC, GC-MS, and LC-MS analyses. Fourier transform infrared spectroscopy (FTIR) confirmed the presence of functional groups such as alkane, amine, and monosubstituted 1,2-disubstituted. The screened bacterial isolate was identified as Bacillus amyloliquefaciens (OR501558) upon 16S rRNA gene sequencing. To our knowledge, this study represents the first-time report on the presence of Bacillus amyloliquefaciens in horse milk having potent antibacterial activity, highlighting its unexplored potential in biotechnological and pharmaceutical applications.

Complete genome sequence of Chryseobacterium sp. strain KCF3-3, isolated from the body surface of channel catfish, Ictalurus punctatus

Here, we report the complete genome sequence of Chryseobacterium sp. strain KCF3-3, isolated from the body surface of channel catfish, Ictalurus punctatus. The de novo assembly revealed a chromosome size of 5,623,437 bp with an estimated 4,939 open reading frames.

Discovery of Papilio bianor Cramer, 1777 (Lepidoptera: Papilionidae) in the Central Ryukyus, Japan: inference of the dispersal pathway based on morphological and genetic analyses

More than 120 species of migrated butterflies have been recorded in the Ryukyu Islands, Japan. Biogeographically, it is important to investigate the origins and characteristics of these species as they might establish populations after accidental migration. In August 2016, a Papilio (Achillides) butterfly was collected on Sesoko Island, approximately 600 m from Okinawa Main Island. Although Papilio (Achillides) ryukyuensis Fujioka is native to this area, the individual had different wing markings from this species. To identify the butterfly and infer its origin, both morphological and genetic analyses were conducted. Morphological analysis indicated that the identification was either Papilio bianor thrasymedes Fruhstorfer from Taiwan or Papilio bianor bianor Cramer from Mainland China. Subsequently, genetic analyses confirmed that the individual should be assigned as P. b. thrasymedes. This suggests that it was migrated from Taiwan, possibly influenced by Typhoon No. 10 of 2016.

Phylogenetic Tree Instability After Taxon Addition: Empirical Frequency, Predictability, and Consequences For Online Inference

Online phylogenetic inference methods add sequentially arriving sequences to an inferred phylogeny without the need to recompute the entire tree from scratch. Some online method implementations exist already, but there remains concern that additional sequences may change the topological relationship among the original set of taxa. We call such a change in tree topology a lack of stability for the inferred tree. In this article, we analyze the stability of single taxon addition in a Maximum Likelihood framework across 1000 empirical datasets. We find that instability occurs in almost 90% of our examples, although observed topological differences do not always reach significance under the approximately unbiased (AU) test. Changes in tree topology after addition of a taxon rarely occur close to its attachment location, and are more frequently observed in more distant tree locations carrying low bootstrap support. To investigate whether instability is predictable, we hypothesize sources of instability and design summary statistics addressing these hypotheses. Using these summary statistics as input features for machine learning under random forests, we are able to predict instability and can identify the most influential features. In summary, it does not appear that a strict insertion-only online inference method will deliver globally optimal trees, although relaxing insertion strictness by allowing for a small number of final tree rearrangements or accepting slightly suboptimal solutions appears feasible.

Plant Growth-Promoting Potential of Colletotrichum sp. Isolated from Ocimum basilicum L. Leaves: A Broad-Spectrum Evaluation

The primary objective of this study was to assess the growth-promoting potential of Colletotrichum sp. as a broad-spectrum plant inoculant and to investigate its applicability beyond its natural host range. Out of ten endophytes isolated from Ocimum basilicum, only four were reported for IAA production and among them, Colletotrichum sp. was chosen for further investigation due to its higher IAA production. Highest production of IAA was observed by providing Czapek dox broth with dextrose as carbon source, ammonium sulphate as nitrogen source at pH 7 and 32 °C. The crude fungal extract from Colletotrichum sp. was tested for its impact on rice plants under different application methods (soil drenching, foliar spraying, and seed immersion). Seed immersion treatment showed a notable effect on the growth of rice seedlings in contrast to soil drenching and foliar spraying. Plant growth assay with fungal elicitor treatment of plantlets produced by shoot culture, supplementing with 0.04 mL of culture filtrate per 30 mL media has significant impact on induction of rooting and overall biomass in Ocimum tenuiflorum as compared to untreated control plants. High-resolution liquid chromatography mass spectrometry (HR-LCMS) analysis of the fungal extract revealed the production of 3-indoleacetic acid and related intermediates.

Ammonifying and phosphorus-solubilizing function of Aliikangiella maris sp. nov. isolated from Phaeocystis globosa bloom and algal-bacterial interactions

Phaeocystis globosa blooms are of escalating global concern due to their substantial ecological impacts on marine ecosystems. Emerging evidence indicates that algae-bacterial interactions play pivotal roles in shaping the ecology and evolution of harmful algal blooms, although much of this interplay remains unexplored. We successfully isolated and propagated two novel bacterial strains from Phaeocystis globosa bloom. Two novel Gram-negative, non-spore-forming, motile, rod-shaped, and yellow-pigmented bacteria were designated strains GXAS 306T and GXAS 311. According to phenotypic, chemotaxonomic, phylogenomic, and comparative genomic analyses data, strains GXAS 306T and GXAS 311 were considered to represent a novel species of the genus Aliikangiella. Genomic analysis revealed that strain GXAS 306T had many potential functions favorable for interacting with algae, and further experimental evidence confirmed the ammonifying and phosphorus-solubilizing function. Co-culture experiments showed that strain GXAS 306T significantly improved algal growth parameters of two typical P. globosa strains (Pg293 and PgV01), particularly under nitrogen or phosphorus deficiency. Specifically, cell densities were observed to increase by 19.6-86.0%, accompanied by substantial enhancements in photosynthetic performance with increases of 8.0-30.6% in F v /F m and 10.9-27.9% in r ETRmax. Overall, these results shed light on intricate relationships between P. globosa and its associated bacterial partners, which may influence the growth characteristics of algae.

Erwinia aeris sp. nov., A Novel Bacterium Isolated from the Surface of an Ore in Hubei Province, China

A novel Gram-stain-negative, phosphate-solubilizing and siderophore producing bacterium, which we designated as strain ACCC 02193T, was separated from ore, collected in Zhongxiang, Hubei of China. Phylogenetic analysis based on 16S rRNA gene sequences showed strain ACCC 02193T is in the genus Erwinia and had highest similarities to Erwinia tasmaniensis DSM 17950T (99.32%) and Erwinia billingiae DSM 17872T (98.77%). However, phylogenomic analyses clearly showed that the strain ACCC 02193T was most closely related to Erwinia phyllosphaerae CMYE1T. The strain grew at 28 °C-30 °C optimally, with 0-6% (w/v) NaCl (optimum 5%), and in the range of pH 4.0-10.0 (optimum pH 8.0). Menaquinone was identified as Q-8. The predominant fatty acids (> 10.0%) were C16:0, C17:0 cyclo, summed feature 3 (C16:1ω7c and/or C16:1ω6c) and summed feature 8 (C18:1ω7c and/or C18:1ω6c). Genome comparisons showed that the strain shared ≤ 82.8% average nucleotide identity (ANI) and ≤ 27.2% in silico DNA-DNA hybridization (DDH) values with closely related type strains, respectively, which supported our conclusion that ACCC 02193T represented a novel species in the genus Erwinia. The DNA G+C content of the strain was 55.7%. Based on the results of physiological and biochemical characteristics, genotypic data, as well as genome comparisons, we demonstrated that type strain ACCC 02193T (= GDMCC 1.4563T = JCM 37069T) is a novel species in the genus Erwinia, and we propose the name Erwinia aeris sp. nov.

Chitinophaga defluvii sp. nov., a Cyhalofop-Butyl-Degrading Bacterium Isolated from Municipal Sludge

A yellow-colored, Gram-stain-negative, non-motile, and rod-shaped bacterium, designated strain H8T, was isolated from municipal sludge in Huaibei, China. Strain H8T was able to grow at 15-37 °C (optimum at 30 °C), pH 6.0-8.0 (optimum at pH 7.0), and 0-2.5% (w/v) NaCl concentration (optimum at 0%). This strain was taxonomically characterized by a polyphasic approach. Based on the 16S rRNA gene sequence analysis, strain H8T represented to the genus Chitinophaga and shared highest sequence similarities with C. arvensicola DSM 3695T (97.5%), C. niastensis JS16-4T (97.3%), C. hostae 2R12T (97.1%), and C. ginsengisegetis Gsoil 040T (96.8%). The 16S rRNA gene similarities with other members of the genus Chitinophaga are less than 96.3%. The only respiratory quinone was a menaquinone with seven isoprene units (MK-7); the major polar lipid was phosphatidylethanolamine; and the predominant fatty acids were iso-C15:0 and C16:1 ω5c. The genome size of strain H8T was 7.6 Mb, with 44.3% G + C content. The DNA-DNA relatedness and the average nucleotide identity values among strain H8T and other relatives were all less than 19.7% and 72.6%, respectively, which fall below the threshold value of 70% and 95% for the strain to be considered as novel. The morphological, physiological, chemotaxonomic, and phylogenetic analyses clearly distinguished this strain from its closest phylogenetic neighbors. Thus, strain H8T represents a novel species of the genus Chitinophaga, for which the name Chitinophaga defluvii sp. nov. is proposed. The type strain is H8T (= CCTCC AB 2023228T = KCTC 102174T).

m5C and m6A modifications regulate the mobility of pumpkin CHOLINE KINASE 1 mRNA under chilling stress

Mobile messenger RNAs (mRNAs) serve as crucial long-distance signaling molecules, responding to environmental stimuli in plants. Although many mobile transcripts have been identified, only a limited subset has been characterized as functional long-distance signals within specific plant species, raising an intriguing question about whether the prevalence of species specificity in mobile transcripts implies a divergence in the mechanisms governing mRNA mobility across distinct plant species. Our study delved into the notable case of CHOLINE KINASE 1 (CK1), an extensively studied instance of mobile mRNAs regulated by a transfer RNA-like sequence (TLS) in Arabidopsis (Arabidopsis thaliana). We established an association between mRNA mobility and length, independent of TLS numbers. Notably, neither the mobile mRNAs nor the mechanisms underpinning their mobility proved to be conserved across different plant species. The exclusive mobility of pumpkin CK1 mRNA under chilling stress was pivotal in enhancing the chilling tolerance of cucumber/pumpkin heterografts. Distinct from the TLS-mediated mobility of AtCK1 mRNA, the mobility of CmoCK1 mRNA is orchestrated by both m5C and m6A modifications, adding dimensions to our understanding of mRNA transport mechanisms.

Major facility superfamily sugar transporter protein SsMFSST1 regulates Sporisorium scitamineum mating, pathogenicity, and sugar transport/absorption

Sugarcane smut caused by Sporisorium scitamineum is a global sugarcane disease, and studying its molecular pathogenesis is crucial for discovering new prevention and control targets. This study was based on the transcriptome sequencing data of two isolates with different pathogenicities (Ss16 and Ss47) of the S. scitamineum and screened out a gene encoding the Major Facility Superfamily (MFS) sugar transporter protein and named it SsMFSST1. Knockout mutants (∆SsMFSST1+ and ∆SsMFSST1-) and complementary mutants (COMMFSST1+ and COMMFSST1-) were obtained through polyethylene glycol (PEG)-mediated protoplast transformation technology. On this basis, the function of gene SsMFSST1 was analyzed. The research results showed that the sexual mating ability of the knockout mutants significantly decreased compared with the wild type, while the sexual mating ability of the complementary mutants was almost restored to the level of the wild type. After the addition of exogenous small molecular signaling substance cyclic adenosine monophosphate (cAMP) or tryptophol required for the sexual mating of S. scitamineum, the sexual mating ability of the knockout mutants was almost restored to the level of the wild type. It was observed that the expression levels of the key genes Uac1 for cAMP synthesis and Aro8 for tryptophol synthesis were significantly lower in the knockout mutants compared with the wild type. However, the expression levels of these genes in the complementary mutants were restored to the wild-type levels. The pathogenicity testing also found a significant decrease in the pathogenicity of combinations containing mutants. On YePSA medium, the gene SsMFSST1 does not affect the growth, spore morphology, colony morphology, and oxidative stress ability of the haploid spores of S. scitamineum. Therefore, we speculate that the SsMFSST1 gene may regulate the expression of key genes related to the synthesis pathway of the small molecule signaling substance cAMP or tryptophol, affecting the synthesis of the signaling substance cAMP or tryptophol, thereby affecting the sexual mating and pathogenicity of S.scitamineum. In addition, this gene also regulates the transport/absorption of fructose and lactose in S. scitamineum. In summary, this study identified a novel pathogenic gene in the S. scitamineum-the MFS sugar transporter gene, providing a molecular basis for understanding the pathogenic mechanism of the S. scitamineum. On the other hand, it also enriches the biological functions of this gene in fungi.IMPORTANCESugarcane is an important economic crop, but the sugarcane smut disease caused by S. scitamineum severely damages the yield and quality of sugarcane, causing huge economic losses on the sugarcane industry. Therefore, it is very necessary to study the pathogenic mechanism of S. scitamineum, especially at the molecular level. This manuscript identified a new pathogenic gene and discovered a new pathogenic mechanism of this gene in S. scitamineum, enriched the molecular pathogenesis of S. scitamineum, and provided a new target for the prevention and control of sugarcane smut disease.

Cell-cell heterogeneity in phosphoenolpyruvate carboxylase biases early cell fate priming in Dictyostelium discoideum

Glucose metabolism is a key factor characterizing the cellular state during multicellular development. In metazoans, the metabolic state of undifferentiated cells correlates with growth/differentiation transition and cell fate determination. Notably, the cell fate of the Amoebozoa species Dictyostelium discoideum is biased by the presence of glucose and is also correlated with early differences in intracellular ATP. However, the relationship between early cell-cell heterogeneity, cell differentiation, and the metabolic state is unclear. To address the link between glucose metabolism and cell differentiation in D. discoideum, we studied the role of phosphoenolpyruvate carboxylase (PEPC), a key enzyme in the PEP-oxaloacetate-pyruvate node, a core junction that dictates the metabolic flux of glycolysis, the TCA cycle, and gluconeogenesis. We demonstrate that there is cell-cell heterogeneity in PEPC promoter activity in vegetative cells, which depends on nutrient conditions, and that cells with high PEPC promoter activity differentiate into spores. The PEPC null mutant exhibited an aberrantly high prestalk/prespore ratio, and the spore mass of the fruiting body was glassy and consisted of immature spores. Furthermore, the PEPC null mutant had high ATP levels and low mitochondrial membrane potential. Our results suggest the importance of cell-cell heterogeneity in the levels of metabolic enzymes during early cell fate priming.

Revisiting the genus Diplodoma Zeller, 1852 in Europe: DNA barcoding reveals the presence of an undescribed species from forested habitats of southern Italy (Lepidoptera: Psychidae)

Diplodoma Zeller, 1852 is a Eurasian genus belonging to the family Psychidae Boisduval, 1829 of which three species are known in Europe: Diplodoma adspersella Heinmann, 1870, D. laichartingella (Goeze, 1783), and D. taurica Zagulajev, 1986. Some authors have argued that Diplodoma adspersella may be a subspecies or even a form of D. laichartingella. The revision of literature and the study of DNA barcoding fragments confirmed the inconsistency of D. adspersella as a valid species, and therefore we propose the new synonymy of Diplodoma adspersella with D. laichartingella (syn. nov.). During recent surveys in southern Italy, three specimens of Diplodoma were collected. DNA barcoding and morphological analyses showed that COI sequences and male genitalia significantly differ from any previously studied specimen. As a result, we described Diplodoma giulioregenii sp. nov., leaving unaltered the number of species belonging to this genus known from Europe.

Characterization of NWM-1, a novel subclass B3 metallo-β-lactamase found in a clinical isolate of Pseudomonas aeruginosa

OBJECTIVES

To investigate the carbapenem resistance mechanism of a carbapenem-resistant clinical Pseudomonas aeruginosa isolate.

METHODS

A clinical isolate of P. aeruginosa was sent to the German National Reference Centre for multidrug-resistant Gram-negative bacteria for carbapenemase detection. Phenotypic tests for carbapenemase detection and an EDTA-combined disc test were positive, therefore PCR-screenings were done for the most prevalent metallo-β-lactamase (MBL) encoding genes. As no MBL gene could be found, whole-genome sequencing was performed. For characterization, heterologous expression in a E. coli strain with subsequent MIC testing and purification of the new MBL to determine enzyme kinetics with in vitro hydrolysis assays was performed.

RESULTS

WGS revealed the putative gene for a B3 MBL located on the chromosome between several disrupted IS elements with 67% identity to EVM-1, which was named NWM-1. MIC studies and enzyme kinetics confirmed MBL activity. No activity against ceftazidime was observed.

CONCLUSIONS

The identification of NWM-1 shows the importance of WGS to identify yet unknown carbapenemases and underlines the diversity of subclass B3 β-lactamases. It also shows that although several carbapenemase variants have already been identified and characterized, there are always new variants to be found in clinical isolates.

Isolation and characterization of Salmonella Typhimurium monophasic variant phage and its application in foods

Salmonella Typhimurium monophasic variant (STm) is an emerging Salmonella serotype that causes food poisoning through the contamination of various foods, including animal products, vegetables, and fruits. In particular, the increasing prevalence of multidrug-resistant STm highlights the urgent need to develop effective strategies to control this pathogen. In this work, a novel and broad-spectrum Salmonella phage named vB_Sal_TmvP009 was isolated and characterized. Morphological and genomic analyses revealed that phage vB_Sal_TmvP009 belonged to the genus Jerseyvirus. Phage vB_Sal_TmvP009 was tolerant to a wide range of temperatures (-20°C∼60°C) and pH values (3∼12). The optimal multiplicity of phage infection was 0.0001, and it had a shorter latent period (8 min), longer lysis period (70 min), and a burst size of 292 PFU/cell. A total of 13 Salmonella serotypes could be lysed by phage vB_Sal_TmvP009. Furthermore, phage vB_Sal_TmvP009 inhibited the growth of multidrug-resistant Salmonella in lettuce or milk with the highest suppression of 3.4 and 3.7 log CFU/mL within 24 h, respectively. The genome of phage vB_Sal_TmvP009 contains lysin and spanin protein, but no tRNA, virulence factors, or drug resistance-related genes. These findings suggest that phage vB_Sal_TmvP009 is a promising antibacterial agent for controlling Salmonella in the food industry.

Characterization of heat, salt, acid, alkaline, and antibiotic stress response in soil isolate Bacillus subtilis strain PSK.A2

Microbes play an essential role in soil fertility by replenishing the nutrients; they encounter various biotic and abiotic stresses disrupting their cellular homeostasis, which expedites activating a conserved signaling pathway for transient over-expression of heat shock proteins (HSPs). In the present study, a versatile soil bacterium Bacillus subtilis strain PSK.A2 was isolated and characterized. Further, the isolated bacterium was exposed with several stresses, viz., heat, salt, acid, alkaline, and antibiotics. Stress-attributed cellular morphological modifications such as swelling, shrinkage, and clump formation were observed under the scanning electron microscope. The comparative protein expression pattern was studied by SDS-PAGE, relative protein stabilization was assessed by protein aggregation assay, and relative survival was mapped by single spot dilution and colony-counting method under control, stressed, lethal, and stressed lethal conditions of the isolate. The findings demonstrated that bacterial stress tolerance was maintained via the activation of various HSPs of molecular weight ranging from 17 to 115 kD to respective stimuli. The treatment of subinhibitory dose of antibiotics not interfering protein synthesis (amoxicillin and ciprofloxacin) resulted in the expression of eight HSPs of molecular weight ranging from 18 to 71 kD. The pre-treatment of short stress dosage showed endured overall tolerance of bacterium to lethal conditions, as evidenced by moderately enhanced total soluble intracellular protein content, better protein stabilization, comparatively over-expressed HSPs, and relatively enhanced cell survival. These findings hold an opportunity for developing novel approaches towards enhancing microbial resilience in a variety of conditions, including industrial bioprocessing, environmental remediation, and infectious disease management.

Campylobacter molothri sp. nov. isolated from wild birds

Twenty-nine hippuricase-positive Campylobacter strains were isolated from wild birds and river water. Previous characterization using atpA typing indicated that these strains were related to Campylobacter jejuni and Campylobacter coli but were most similar to three recently described hippuricase-positive Campylobacter species recovered from zebra finches, i.e. C. aviculae, C. estrildidarum and C. taeniopygiae. Phylogenetic analyses using 330 core genes placed the 29 strains into a clade well separated from the other Campylobacter taxa, indicating that these strains represent a novel Campylobacter species. Pairwise digital DNA-DNA hybridization and average nucleotide identity values were below 70 and 95 %, respectively, thus providing further supporting evidence of a novel taxon. Standard phenotypic testing was performed. All strains are microaerobic or anaerobic, motile, Gram-negative, spiral cells that are oxidase, catalase and nitrate reductase positive, but urease negative. Genomic analyses indicate that the 29 strains can potentially synthesize very few amino acids de novo and are auxotrophic for many amino acids and cofactors, similar to the species composing the Campylobacter lari group. In addition, these strains encode complete Entner-Doudoroff and Leloir pathways, suggesting that they may possess the ability to utilize both glucose and galactose; these pathways were also identified in the genomes of the zebra finch-associated taxa. The data presented here show that these strains represent a novel species within Campylobacter, for which the name Campylobacter molothri sp. nov. (type strain RM10537T=LMG 32306T=CCUG 75331T) is proposed.

Isolation and characterization of Novosphingobium aquae sp. nov. and Novosphingobium anseongense sp. nov., isolated from freshwater

Two novel Gram-stain-negative, aerobic, heterotrophic, non-motile bacterial strains, designated as AS3R-12T and PS1R-30T, were isolated from freshwater in South Korea. To determine their taxonomic positions, the strains were thoroughly characterized. Genomic analyses, based on 16S rRNA gene and draft genome sequence data, revealed that the two novel isolates, AS3R-12T and PS1R-30T, belonged to the genus Novosphingobium. AS3R-12T showed the highest 16S rRNA gene similarity (97.7%) with Novosphingobium flavum UCT-28T. In addition, PS1R-30T showed 97.9% 16S rRNA gene similarity with Novosphingobium lentum NBRC 107847T. The draft genome of strains AS3R-12T and PS1R-30T consisted of 4 149 275 and 4 969 838 bps, with DNA G+C content of 63.1 and 66.1 mol%, respectively. The average nucleotide identity between two strains and other related species was below 76.2%, and the digital DNA-DNA hybridization values with closely related species were below 20.8%, both lower than the species delineation threshold. Strains AS3R-12T and PS1R-30T contained the ubiquinone Q-10 as the major quinone and displayed a polyamine pattern with spermidine as the predominant polyamine. Additionally, their major fatty acids were characterized by C16:1  ω7c/C16:1  ω6c (summed feature 3) and C18:1  ω7c/C18:1  ω6c (summed feature 8). The major polar lipids of AS3R-12T and PS1R-30T were diphosphatidylglycerol (DPG), phosphatidylglycerol (PG), phosphatidylethanolamine (PE), sphingoglycolipid (SGL) and phosphatidylcholine (PC). Moreover, physiological and biochemical results allowed the phenotypic and genotypic differentiation of strains AS3R-12T and PS1R-30T from their closest and other species of the genus Novosphingobium with validly published names. Therefore, AS3R-12T and PS1R-30T represented novel species of the genus Novosphingobium, for which the names Novosphingobium aquae sp. nov. (type strain AS3R-12T=KACC 23096T=LMG 32950T) and Novosphingobium anseongense sp. nov. (type strain PS1R-30T=KACC 23097T=LMG 32951T) are proposed.

Alteration of the Catalytic Properties of the Epoxyalcohol Synthase CYP443D1 (NvEAS) of the Starlet Sea Anemone Nematostella vectensis as a Result of a Single Amino Acid Substitution

Cytochromes of the P450 superfamily are widespread in nature; they were found in all studied aerobic organisms. Although the degree of similarity between cytochromes P450 of different families is low, all enzymes of this superfamily have similar tertiary structures. In addition, all cytochromes P450, including enzymes of the CYP74 clan, contain substrate recognition sites in their sequences, which form the catalytic center. Initially, CYP74 enzymes were discovered in plants, where they are widespread and play an important role in the lipoxygenase cascade. Later, CYP74-like enzymes of other families were identified in different taxa, including animals. Based on the results of phylogenetic studies, structures, and catalytic mechanisms, they were combined along with the CYP74 family into the CYP74 clan. One of the CYP74 clan enzymes is the epoxyalcohol synthase NvEAS (CYP443D1) of the starlet sea anemone Nematostella vectensis. A mutant form of NvEAS with a P93G substitution, that acquired additional hydroperoxide lyase activity, was obtained by site-directed mutagenesis. Before this work, only the results of site-directed mutagenesis of enzymes of the CYP74 family, but not of the CYP74 clan, were described. Moreover, in this work, the transformation of epoxyalcohol synthase into hydroperoxide lyase is described for the first time. These results confirm the previously stated assumption about the evolution of CYP74 enzymes, namely the epoxyalcohol synthase - hydroperoxide lyase - allene oxide synthase - divinyl ether synthase pathway.

Antibacterial and antibiofilm properties of two cyclic dipeptides produced by a new desert Streptomyces sp. HG-17 strain against multidrug-resistant pathogenic bacteria

INTRODUCTION

The emergence of multidrug-resistant bacteria and biofilms requires discovering new antimicrobial agents from unexplored environments.

OBJECTIVES

This study aims to isolate and characterize a new actinobacterial strain from the Hoggar Mountains in southern Algeria and evaluate its ability to produce bioactive molecules with potential antibacterial and antibiofilm activities.

METHODS

A novel halotolerant actinobacterial strain, designated HG-17, was isolated from the Hoggar Mountains, and identified based on phenotypic characterizations, 16S rDNA sequence analysis, and phylogenetic analysis. The antibacterial and antibiofilm activities of the strain were assessed, and the presence of biosynthetic genes (PKS-I and NRPS) was confirmed. Two active compounds, HG-7 and HG-9, were extracted butanol solvent, purified by HPLC, and their chemical structures were elucidated using ESI mass spectrometry and NMR spectroscopy.

RESULTS

The strain HG-17 was identified as Streptomyces purpureus NBRC with 98.8% similarity. It exhibited strong activity against multidrug-resistant and biofilm-forming bacteria. The two purified active compounds, HG-7 and HG-9, were identified as cyclo-(d-cis-hydroxyproline-l-phenylalanine) and cyclo-(l-prolone-l-tyrosine), respectively. The minimum inhibitory concentrations (MICs) of HG-7 and HG-9 ranged from 3 to 15 μg/mL, comparable to the MICs of tetracycline (8 to 15 μg/mL). Their minimum biofilm inhibitory concentration (MBIC 50%) showed good inhibition from 48.0 to 52.0% at concentrations of 1 to 7 μg/mL against the tested bacteria.

CONCLUSION

This is the first report of cyclo-(d-cis-hydroxyproline-l-phenylalanine) and cyclo-(l-prolone-l-tyrosine) antibiotics from S. purpureus and their anti-multi-drug-resistant and biofilm-forming bacteria. These results indicate that both antibiotics could be used as effective therapeutics to control infections associated with multidrug-resistant bacteria.

High Microsatellite but No Mitochondrial DNA Variation in an Invasive Japanese Mainland Population of the Parasitoid Wasp Melittobia sosui

Invasive populations are predicted to have reduced genetic diversity due to bottleneck events. The parasitoid wasp Melittobia sosui was previously identified only in the subtropical area of the southern Japanese islands and Taiwan but was recently found in the temperate area of the Japanese mainland. The distribution of this species may have recently expanded northward due to factors such as climatic events and global warming. The population genetics of both the native and invasive regions were investigated using mitochondrial and nuclear microsatellite DNA. As expected, mitochondrial variation was observed in the native region but not in the invasive region, which had only one haplotype. However, the two regions exhibited similar levels of microsatellite variation, and an average of 43% and 38% of alleles were uniquely found in the native and invasive populations, respectively. The difference in genetic variation between mitochondrial and microsatellite DNA in the invasive populations may be explained by the faster mutation rate of microsatellites, as well as the population structure of Melittobia, in which the subdivision into small inbreeding lineages may facilitate the accumulation of mutations. The high proportion of private alleles suggests that the mainland population diverged from the native populations at least 100 years ago, ruling out the possibility that the mainland population was established recently. The present study suggests that M. sosui might have already existed on the mainland but at a low frequency or that the mainland population was derived from a ghost population that diverged from the native populations more than 100 years ago.

Streptococcus wuxiensis sp. nov., Streptococcus jiangnanensis sp. nov. and Streptococcus fermentans sp. nov.: three novel species of genus Streptococcus isolated from human breast milk

Three novel coccoid-shaped strains, designated 21WXBC0057M1T, 21WXBC0044M1T and BJSWXB5TM5T, were isolated from human breast milk in Wuxi, Jiangsu Province, China. These strains were facultative anaerobes, catalase-negative and Gram-positive. Through a comprehensive analysis of rRNA genes, protein-coding housekeeping genes and genomic phylogeny, we identified these strains as belonging to the genus Streptococcus. Specifically, strain 21WXBC0057M1T was phylogenetically most closely related to Streptococcus infantis, strain 21WXBC0044M1T was most closely related to Streptococcus oralis and strain BJSWXB5TM5T displayed similarities to Streptococcus australis, Streptococcus peroris and S. infantis. The pairwise average nucleotide identity and digital DNA-DNA hybridization values for these three strains were below 95 and 70%, respectively, indicating that they occupied evolutionary branches distinct from all previously validly published Streptococcus species. Distinctive phenotypic characteristics discriminated these novel species from the type strains of their most closely related species. The major cellular fatty acids in the three strains were C16 : 0 and C18 : 0. Genome annotation and a thorough examination of carbohydrate-active enzyme distribution highlighted the observation that all strains possessed extensive capabilities for carbohydrate metabolism, particularly human milk oligosaccharides utilization. Thus, based on these findings, we proposed the classification of the strains as representing three novel species within the genus Streptococcus: Streptococcus wuxiensis sp. nov. (type strain 21WXBC0057M1T=GDMCC 1.4126T=KCTC 25760T), Streptococcus jiangnanensis sp. nov. (type strain 21WXBC0044M1T= GDMCC 1.4127T=KCTC 25762T) and Streptococcus fermentans sp. nov. (type strain BJSWXB5TM5T=GDMCC 1.4130T=KCTC 25759T).

Paenibacillus mesotrionivorans sp. nov., a Mesotrione-Degrading Strain Isolated from Soil

A Gram-stain-positive, facultatively anaerobic, motile with peritrichous flagella, and rod-shaped bacterium, designated as P15T, was isolated from an agricultural soil sample collected in Jiangxi Province, PR China. Strain P15T completely degraded 100 mg/L of mesotrione, a herbicide, within 48 h of incubation. Strain P15T grew at 15-42 °C (optimum 30 °C), pH 6.0-9.0 (optimum 7.0), and 0-4.0% (w/v) NaCl (optimum 1.0%). Strain P15T exhibited less than 93.3% 16S rRNA gene sequence similarity with type strains of genus Paenibacillus. In the phylogenetic tree based on 16S rRNA gene sequences, strain P15T was clustered in genus Paenibacillus and formed a subclade with P. cavernae C4-5T, P. contaminans CKOBP-6T, and P. doosanensis CAU 1005T. The major cellular fatty acids (≥ 5% of the total) were anteiso-C15:0, iso-C16:0, C14:0, C16:0, and iso-C14:0. The predominant respiratory quinone was MK-7. The major polar lipids were diphosphatidylglycerol, phosphatidylglycero, phosphatidylethanolamine, one unidentified glycolipid, one unidentified aminophosphoglycolipid, two unidentified aminophospholipids, two unidentified phospholipid, and two unidentified lipids. The diagnostic diamino acid of the peptidoglycan was meso-diaminopimelic acid. The DNA G + C content was 53.9 mol%. Based on the phylogenetic, phenotypic, and chemotaxonomic characteristics, strain P15T represents a novel species within genus Paenibacillus, for which the name Paenibacillus mesotrionivorans sp. nov is proposed, with strain P15T (= MCCC 1K09191T = KCTC 43705T) as the type strain.

In Silico Characterization of Sirtuins in Acetic Acid Bacteria Reveals a Novel Phylogenetically Distinctive Group

Acetic acid bacteria are single-celled organisms well-known for their ability to convert ethanol into acetic acid. Still, recent research suggests they may harbor another attractive characteristic-the production of proteins with remarkable similarities to sirtuins. Sirtuins have been linked to lifespan extension in various organisms, raising intriguing questions about the potential connection between acetic acid bacteria and the biology of aging. This article delves into the characterization of sirtuin homologs in acetic acid bacteria. Up to three types of sirtuin homologs have been identified in 21% of acetic acid bacteria genomes deposited in NCBI. All three types were present only in the genera Acetobacter and Novacetimonas, which are known to survive in the harshest environmental conditions (high concentrations of acetic acid and ethanol). Interestingly, two types of these sirtuin homologs (SirAAB-L and SirAAB-S) constitute a separate group (SirAAB), distinctive from all other presently known sirtuins. The results obtained in silico thus encourage further studies into the function of these types of sirtuins and their interplay with metabolic pathways in these industrially important bacteria.

Multi-Omics Analysis Decodes Biosynthesis of Specialized Metabolites Constituting the Therapeutic Terrains of Magnolia obovata

Magnolia obovata is renowned for its unique bioactive constituents with medicinal properties traditionally used to treat digestive disorders, anxiety, and respiratory conditions. This study aimed to establish a comprehensive omics resource through untargeted metabolome and transcriptome profiling to explore biosynthesis of pharmacologically active compounds of M. obovata using seven tissues: young leaf, mature leaf, stem, bark, central cylinder, floral bud, and pistil. Untargeted metabolomic analysis identified 6733 mass features across seven tissues and captured chemo-diversity and its tissue-specificity in M. obovata. Through a combination of cheminformatics and manual screening approach, we confirmed the identities of 105 metabolites, including neolignans, such as honokiol and magnolol, which were found to be spatially accumulated in the bark tissue. RNA sequencing generated a comprehensive transcriptome resource, and expression analysis revealed significant tissue-specific expression patterns. Omics dataset integration identified T12 transcript module from WGCNA being correlated with the biosynthesis of magnolol and honokiol in M. obovata. Notably, phylogenetic analysis using transcripts from T12 module identified two laccase (Mo_LAC1 and Mo_LAC2) and three dirigent proteins from the DIR-b/d subfamily as potential candidate genes involved in neolignan biosynthesis. This research established omics resources of M. obovata and laid the groundwork for future studies aimed at optimizing and further understanding the biosynthesis of metabolites of therapeutic potential.

Insight into the phylogeny and antibiotic resistance of Pseudomonas spp. originating from soil of the Białowieża National Park in Northeastern Poland

The Pseudomonas genus includes species present in various environments and known for antibiotic resistance. However, only hospital-associated Pseudomonas aeruginosa have been extensively studied regarding antibiotic resistance. Thus, to fill the gap in knowledge on antibiotic resistance among other Pseudomonas spp., we investigated 41 isolates from soil samples taken in the Białowieża National Park in Northeastern Poland. This unique forest without notable anthropogenic influence, provides excellent conditions for research of antibiotic resistance from the perspective of natural environments. The phylogeny trees obtained based on the nucleotide sequence of the 16S rRNA gene and gyrB gene grouped the isolates into clusters belonging to the Pseudomonas fluorescens, Pseudomonas koreensis, and Pseudomonas putida groups, originating from the P. fluorescens lineage. All isolates under study demonstrated resistance to at least 12 out of the 24 antibiotics tested. Resistance to colistin, cefotaxime, and imipenem was detected in 73, 73, and 17% of the isolates, respectively. Most isolates showing resistance to imipenem and colistin clustered within the P. fluorescens group. Seven isolates were highly multi-resistant, to up to 18 of the 24 antibiotics tested. The presence of resistance genes related to intrinsic resistance of P. aeruginosa has been confirmed in environmental isolates.

Reclassification of Salisediminibacterium haloalkalitolerans Sultanpuram et al. 2015 as a Later Heterotypic Synonym of Salisediminibacterium halotolerans Jiang et al. 2012

In the present study, the taxonomic position of Salisediminibacterium haloalkalitolerans was evaluated by determining the 16S rRNA gene sequence similarity, genome relatedness, and phylogenetic analyses. The 16S rRNA gene sequences extracted from the genomes of Salisediminibacterium haloalkalitolerans 10nlgT and Salisediminibacterium halotolerans DSM 26530T showed 100% similarity, supporting their classification as the same species. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between S. haloalkalitolerans and S. halotolerans were 97.7 and 80.2%, respectively, above the cutoff value (95-96% ANI; 70% dDDH) for species delineation. S. haloalkalitolerans and S. halotolerans should be classified as the same species because the 16S rRNA gene phylogeny and phylogenomic tree (based on 71 bacterial single-copy genes) showed no genetic divergence between them. Based on the above results and the rule of priority in nomenclature, we propose to reclassify Salisediminibacterium haloalkalitolerans Sultanpuram et al. 2015 as a later heterotypic synonym of Salisediminibacterium halotolerans Jiang et al. 2012.

The conserved IR75 subfamily mediates carboxylic acid detection in insects of public health and agricultural importance

Insects perceive and respond to carboxylic acids (CAs), amines, and aldehydes primarily via conserved ionotropic receptors (IRs). These receptors form the basis for a second olfactory system distinct from the well-characterized odorant receptors. Neurons expressing IRs are housed in dedicated sensilla and innervate glomeruli, separate from those innervated by odorant receptor neurons. The IR8a co-receptor is highly conserved across insect orders and, together with ionotropic receptor tuning receptors, primarily detects CAs. The conservation of genes and the anatomical separation of neural pathways underscore the importance of these compound classes and CAs, specifically in insect chemical ecology. We provide a summary of carboxylic acid detection in insects, focusing on dipteran and lepidopteran species of significance to public health and agriculture. An overview of insect behavior toward CAs is provided, as well as a comprehensive update on carboxylic acid receptor function in insects. Phylogenetic analysis of publicly available genome databases reveals several species that encode and express homologs of previously deorphanized carboxylic acid receptors, highlighting avenues for future research.

Occurrence of Antibiotic-Resistant Bacteria in Urban Surface Water Sources in Bangladesh

Infections caused by antibiotic-resistant bacteria (ARB) result in an estimated 1.27 million human deaths annually worldwide. Surface waters are impacted by anthropogenic factors, which contribute to the emergence and spread of ARB in the aquatic environment. While research on antibiotic resistance in surface waters has increased recently in developing nations, including Bangladesh, especially in aquaculture, such studies are still limited in Bangladesh compared to developed nations. In this study, bacteria strains isolated from three rivers and two lakes in Khulna city, Bangladesh were characterized for their antibiotic resistance using disk diffusion method. Of the 106 bacterial isolates from 180 surface water samples, the majority exhibited resistance to Ciprofloxacin (75.0-87.5%) and Ceftriaxone (65.6-78.1%), while resistance to Ampicillin was comparatively lower (9.4-18.8%). Notably, the prevalence of ARB was observed to be higher during the wet seasons compared to the dry seasons. The 16S rRNA gene analysis showed that Shigella flexneri was the most dominant (17.9%) bacterium among the ARB cultured from surface waters, followed by Escherichia fergusonii (12.5%), Proteus mirabilis (10.7%), and Enterobacter quasiroggenkampii (8.9%). At the genus level, Enterobacter (23.5%), Shigella (20.6%), and Escherichia spp. (14.7%) were the most abundant among the ARB in both river and lake samples. The findings of this study highlight the prevalence of antimicrobial resistance in surface water sources and suggest the need for enhanced monitoring and improved disposal practices to mitigate potential public health risks.

Gallibacterium faecale sp. nov., Isolated from Dairy Cow Feces

A facultative anaerobic, Gram-stain-negative, non-motile, rod-shaped bacterial strain AGMB14963T was isolated from the feces of a dairy cow. A 16S rRNA gene sequence-based phylogenetic analysis revealed that strain AGMB14963T belongs to the genus Gallibacterium, with Gallibacterium salpingitidis F150T being the closest species (95.8% 16S rRNA gene sequence similarity). Whole-genome sequence analysis revealed that strain AGMB14963T had a 37.0% G + C genomic DNA content and a genome size of 2.58 Mb. In addition, the strain contained 53 tRNA and 2 rRNA genes. The average nucleotide identity and digital DNA-DNA hybridization values between strains AGMB14963T and G. salpingitidis F150T were 82.3 and 24.9%, respectively. Further, strain AGMB14963T was positive for oxidase and catalase, but negative for urease. Optimal growth of strain AGMB14963T occurred at 37 ℃, pH 8, and in 0.5% NaCl-containing medium. The predominant cellular fatty acids (> 10%) in strain AGMB14963T were C14:0, C16:0, and summed feature 3. Strain AGMB14963T produced lactic acid and isobutyric acid as the major end products of glucose fermentation. Polar lipids consisted of one phospholipid and one phosphoaminolipid. According to the genomic, physiologic, and chemotaxonomic characteristics, strain AGMB14963T represents a novel species of the genus Gallibacterium, for which the name Gallibacterium faecale sp. nov. is proposed. The type strain is AGMB14963T (= KCTC 25487 T = NBRC 116419 T).

Intrasporangium zincisolvens sp. nov., A Novel Actinobacterium Isolated from Rhizosphere Soil

A novel phosphate-solubilizing and zinc-solubilizing actinobacterium strain YIM S08009T was isolated from rhizosphere soil collected from Pinus yunnanensis in Wuliangshan National Nature Reserve, Pu'er City, Yunnan Province, southwest PR China. Cells of strain YIM S08009T were Gram-stain-positive, non-motile, irregular rods to cocci, and formed yellow and white colonies on nutrient agar. Growth was observed at 10-40 °C (optimum 25-35 °C), pH 6.0-8.5 (optimum 7), and 0-4% (w/v) NaCl (optimum 1%). The cell wall peptidoglycan contained LL-diaminopimelic acid. The whole-cell sugars were mannose, ribose, glucose, and galactose. The predominant menaquinone was MK-8(H4). Major polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, unknown lipid, and 3 unknown phospholipids. The predominant fatty acids were iso-C14:0, iso-C15:0, and iso-C16:0. The DNA G + C content was 72.6%. A phylogenetic analysis based on 16S rRNA gene sequences showed that strain YIM S08009T belonged to genus Intrasporangium, and was most closely related to Intrasporangium flavum MUSC 78T, with 99.0% 16S rRNA gene sequence similarity. Strain YIM S08009T shared 90.1% orthologous average nucleotide identity (OrthoANI) and 39.8% digital DNA-DNA hybridization (dDDH) with I. flavum MUSC 78T. The genome of strain YIM S08009T contained phosphate-solubilizing genes (SenX3, RegX3, pstSCAB, ugpBAEC, phoA) and zinc-solubilizing genes (znuABC, zupT), and the strain had also demonstrated in vitro phosphorus and zinc solubilization. Based on the genotypic and phenotypic analyses, strain YIM S08009T (= CGMCC 1.60168T = NBRC 116604T = KCTC 59021T) represents a novel Intrasporangium species, for which the name Intrasporangium zincisolvens sp. nov. is proposed.

Alternaria radicina; unveiling the cause, spread, and molecular basis of a novel coriander leaf blight disease in Egypt

Coriandrum sativum L. faced a new and previously undocumented leaf blight disease for the first time. This disease manifests initially as small, circular, or irregular brown spots on older leaves, which gradually expand and merge into dark brownish blotches over time. This disease's impact is detrimental to plant health and seed quality. Through comprehensive morphological characteristics, and molecular identification (GenBank OL823169), the pathogen was conclusively identified as Alternaria radicina. Further confirmation was obtained by analyzing target sequences for the Alt-a-1 gene (GenBank OR492259). Koch's postulates were strictly adhered to, leading to the successful re-isolation of A. radicina from artificially infected 8-week-old coriander plants (local variety; Balady), providing unequivocal evidence that the fungus is responsible for leaf blight disease, marking the first such confirmation worldwide. The significant activity of fungal enzymes may be associated with pathogenicity. The seed-health test supported the hypothesis that seeds play a central role in the transmission of A. radicina, as it was detected in 40 % of seed lots, alongside other common pathogenic and saprophytic genera. This study underscores the urgency of implementing seed treatments to curtail the pathogen's spread. The emergence of coriander leaf blight disease documented here (Egypt; 30° 57' 25″ N and 31° 35 ' 54″E) for the first time, necessitates heightened awareness and proactive measures to protect coriander plants all over the world.

Antimicrobial and Cytotoxic Potential of Endophytic Aspergillus versicolor Isolate from the Medicinal Plant Plectranthus amboinicus

Endophytic fungi are non-pathogenic organisms that colonise healthy plant tissues asymptomatically. Endophytes derived from medicinal plants are sources for identifying natural products and bioactive compounds with potential uses for industry, medicine, agriculture, and related sectors. In the present study, ethyl acetate crude extracts of four endophytic fungal isolates (CALF1, CALF4, and CASF1) from the medicinal plant Plectranthus amboinicus showed potent antimicrobial activity against the test pathogenic bacteria Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Bacillus subtilis using disc diffusion assays. A colorimetric microdilution assay to detect the minimum inhibitory concentration (MIC) revealed that the extracellular extract (ECE) of CASF1 isolate had the lowest MIC values against the test pathogenic bacteria (0.19-6.25 mg/ml) compared to other CALF1 and CALF4. Cytotoxic activity of CASF1-ECE against the drug-resistant KB.CHR.8-5 cancer cell line tested by the MTT assay showed complete cell death at a concentration of 220 μg/mL and the half-maximum inhibitory concentration (IC50) was determined to be 77.9 ± 09 μg/mL. GC-MS analysis showed hexadecanoic acid, 2-hydroxy-1-(hydroxymethyl) ethyl ester, as the dominant compound among the bioactive compounds identified in the EXE of CASF1 isolate, with the highest peak in the GC chromatogram, indicating its role in the antimicrobial and cytotoxic activity of CASF1. Molecular identification of CASF1 using 18S rRNA sequencing and BLAST analysis detected CASF1 as an isolate of Aspergillus versicolor with 100% sequence identity.

Dehalogenimonas Strain W from Estuarine Sediments Dechlorinates 1,2-Dichloroethane under Elevated Salinity

Organohalide-respiring bacteria (OHRB) have been found in various environments and play an indispensable role in the biogeochemical cycling and detoxification of halogenated organic compounds (HOCs). Currently, few ORHB have been reported to perform reductive dechlorination under high salinity conditions, indicating a knowledge gap on the diversity of OHRB and the survival strategy of OHRB in saline environments (e.g., estuarine, marine). This study reports the characterization of an enrichment culture dominated by a new Dehalogenimonas population strain W derived from estuarine sediments, which demonstrates the capability to dechlorinate 1,2-dichloroethane (1,2-DCA) to ethene under elevated salinity (≥5.1% NaCl, w/v). Metagenomic and proteomic analyses revealed that the distinctive high-salinity dechlorination of strain W is primarily attributed to a putative reductive dehalogenase (RDase) DdeA, which shares >91.4% amino acid identity with the dihaloeliminating RDase DcpA from other Dehalogenimonas strains. Additionally, ectoine biosynthesis enzymes (EctABC) contribute to the strain's salt tolerance. These findings underscore the potential of OHRB, particularly Dehalogenimonas, to detoxify HOCs in high-salinity environments, such as estuarine and marine ecosystems, by employing compatible solutes as an adaptive mechanism.

Deep learning-based assessment of missense variants in the COG4 gene presented with bilateral congenital cataract

OBJECTIVE

We compared the protein structure and pathogenicity of clinically relevant variants of the COG4 gene with AlphaFold2 (AF2), Alpha Missense (AM), and ThermoMPNN for the first time.

METHODS AND ANALYSIS

The sequences of clinically relevant Cog4 missense variants (one novel identified p.Y714F and three pre-existing p.G512R, p.R729W and p.L769R from Uniprot Q9H9E3) were imported into AF2 for protein structural prediction, and the pathogenicity was estimated using AM and ThermoMPNN. Different pathogenicity metrics were aggregated with principal component analysis (PCA) and further analysed at three levels (amino acid position, substitution and post-translation) based on all possible Cog4 missense variants (n=14 915).

RESULTS

Localised protein structural impact including change of conformation and amino acid polarity, breakage of hydrogen bond and salt-bridge, and formation of alpha-helix were identified among clinically relevant Cog4 variants. The global structural comparison with multidimensional scaling demonstrated variants with similar protein structures (AF2) tended to exhibit similar clinical and biological phenotypes. The Cog4 p.Y714F variant exhibited greater protein structural similarity to mutated Cog4 found in Saul‒Wilson syndrome (p.G512R) and shared similar clinical phenotype (congenital cataract and psychomotor retardation). PCA of included pathogenic metrics demonstrated p.Y714F occurred at a critical position in Cog4 amino acid sequence with disrupted post-translational phosphorylation.

CONCLUSION

Deep learning algorithms, including AF2, AM and ThermoMPNN, can be useful for evaluating variant of uncertain significance (VUS) by structural and pathogenicity prediction. Despite classified as VUS (American College of Medical Genetics and Genomics criteria: PM1, PP4), the pathogenicity in this Cog4 variant cannot be ruled out and warrants further investigation.

Target site mutations and metabolic detoxification of insecticides in continental populations of Cimex lectularius and Cimex hemipterus (Hemiptera: Cimicidae)

In recent decades, the common and the tropical bed bugs have experienced a resurgence in many parts of the world. The evolution of insecticide resistance in bed bug populations is considered a significant factor contributing to this resurgence. We analyzed samples of Cimex lectularius L. and Cimex hemipterus (F.) from Europe (Spain 41, Switzerland 2, the Czech Republic 1), Asia (Hong Kong 34), North America (USA 14, Mexico 3), and South America (Colombia 3) to assess the prevalence and mechanisms of insecticide resistance. We identified specimens morphologically and barcoded them by sequencing the mitochondrial Cytochrome c oxidase subunit I (COI) and the 16S ribosomal RNA (16S rRNA) genes. Additionally, we screened segments of the voltage-gated sodium channel (VGSC) and the nicotinic acetylcholine receptor (nAChR) genes for point mutations associated with insecticide resistance and measured the activity of detoxifying enzymes. All samples from North America and Europe were identified as C. lectularius, whereas specimens from Hong Kong were C. hemipterus. Out of 64 C. lectularius samples tested for knockdown resistance (kdr) mutations, 90.6% contained at least 1 known mutation. All 35 C. hemipterus samples exhibited kdr mutations. A new mutation was identified in the pyrethroid target site in both common (F1524C) and tropical (F1450C) bed bugs. No resistance-associated mutations in the nAChR gene were found. Several populations that exhibited kdr mutations also showed elevated activity of detoxifying enzymes. The high frequency of kdr-associated mutations in bed bug populations from Spain and Hong Kong limits the efficacy of pyrethroids for their control.

Isolation of New Strains of Lactic Acid Bacteria from the Vaginal Microbiome of Postmenopausal Women and their Probiotic Characteristics

Lactic acid bacteria (LAB), traditionally consumed as fermented foods, are now being applied to the medical field beyond health-functional food as probiotics. Therefore, it is necessary to continuously discover and evaluate new strains with suitable probiotic characteristics, mainly focusing on safety. In this study, we isolated eight new strains from postmenopausal vaginal fluid using culturomics approaches, an emerging area of interest. Data showed that most strains possessed significant cell surface hydrophobicity (≥ 76%), auto-aggregation capacity (17 to 61%), strong adhesion activity (8 to 34%), and excellent resistance to gastric acid, bile salt, and digestive enzyme, enhancing their survival in the gastrointestinal tract. Moreover, the strains exhibited functional characteristics, including substantial antibacterial activity with a minimal inhibitory concentration (MIC) ranging from 12.5 to 50%. They also harbored bacteriocins genes, produced short-chain fatty acids (acetate and propionate), exhibited significant phagocytic activity, possessed high antioxidative properties, rapidly depleted sodium nitrite, and exhibited proteolysis and β-glucosidase activity. In addition, heat-killed LAB strains significantly reduced the gene expressions of proinflammatory cytokines such as IL-β, IL-6, and iNOS in macrophages. Safety assessment revealed no cytotoxicity in macrophage cell lines. All strains tested negative for biogenic amine or H2O2 production, displayed no gelatinase or hemolytic activity, lacked virulence genes or detrimental enzymes, and displayed antibiotic susceptibility. In summary, these newly isolated strains demonstrate excellent probiotic functionality with a strong focus on safety, making them promising candidates for future drug development in the relevant fields.

Exploring novel inhibitors for Babesia bigemina lactate dehydrogenase: a computational structural biology perspective

Babesia bigemina is an apicomplexan parasite responsible for causing "Texas fever" in bovines. Current treatments for bovine babesiosis are hindered by several limitations, including toxicity, insufficient efficacy in eliminating the parasite, and the potential for resistance development. A promising approach to overcome these challenges is the identification of compounds that specifically target essential metabolic pathways unique to the parasite. One such target is lactate dehydrogenase (LDH), a critical enzyme involved in the regulation of anaerobic glycolysis. Notably, Babesia bigemina LDH (BbigLDH) exhibits a five-amino acid insertion in the active site, a feature that differentiates it from the host's LDH. This structural divergence makes apicomplexan LDH an attractive and potentially selective drug target for therapeutic intervention. In this study, a structure-based drug discovery approach was implemented to find novel inhibitor candidates. Potential candidates were identified using a virtual screening workflow. The compounds with favorable docking scores were filtered using the QM-polarized ligand docking and induced fit docking methods. As a result, 20 novel compounds were identified that bind to the active site of BbigLDH but show low affinity to the host LDHs. Molecular dynamics simulations of the complexes (8.8 µs in total) were performed, and binding free energies were calculated. As a result, protein structures containing compounds C9, C16 and C18 maintained their stability throughout 1 µs simulations with low binding free energies and conserved interactions with known catalytic residues. Therefore, these three compounds deserve further investigation to better understand their mode of action and therapeutic potential for babesiosis. The results of this study elucidate the structural features of the BbigLDH enzyme and provide novel LDH binders that may pave the way for further research into the development of parasite-specific LDH inhibitors.

A new species of the genus Myiomma (Heteroptera: Miridae: Isometopinae) from the Korean Peninsula

In this study, we report the genus Myiomma from the Korean peninsula for the first time, with the description of a new species Myiomma koreana sp. nov. A morphological diagnosis for the genus is provided, accompanied by images of the dorsal habitus and female and male genital structures. Additionally, a key is presented for the identification of the 12 known East Asian species of Myiomma. COI sequence data for the new species are included, along with a neighbor-joining (NJ) tree analysis. This analysis revealed that a COI sequence previously submitted to GenBank, attributed to Myiomma kukai Yasunaga & Hayashi 2002, was a misidentification of our new species.

Identification and bioinformatics analysis of the DUS gene in Eimeria media

This study aims to explore the coding sequence (CDS) of the putative DUS gene in Eimeria media and assess its potential biological functions during the parasite's lifecycle. Initially, oocysts were isolated from fecal samples of rabbits infected with E. media, from which DNA and RNA were extracted. These extractions were used as templates for PCR to successfully amplify the CDS of the DUS gene, confirming its presence within the E. media genome. Further analysis using quantitative PCR (qPCR) demonstrated significantly higher expression of the DUS gene in the precocious line (PL) compared to the wild type (WT). This differential expression highlights a potential functional role for the DUS gene in influencing the development and sporulation processes of E. media, which may contribute to the precocious phenotype. Additionally, bioinformatics analysis provided insights into the evolutionary trends and structural characteristics of the DUS gene across different species, suggesting a broader biological significance. The elevated expression of the DUS gene in the PL suggests its critical involvement in the growth and reproductive processes of the parasite. This finding opens new avenues for research aimed at controlling E. media infection through targeted interventions in the DUS gene expression pathways.

Like grains of sand: Ninetis spiders on the Arabian Peninsula (Araneae, Pholcidae)

Ninetinae is a group of small to tiny, short-legged daddy-longlegs spiders (Pholcidae) that has its highest diversity in the New World. Only two genera are known to occur in the Old World: the nominotypical genus Ninetis Simon, 1890 on the Arabian Peninsula and in Africa, and the monotypic genus Magana Huber, 2019 in Oman. Here we redescribe the type species of Ninetis, N. subtilissima Simon, 1890, and describe three new species from the Arabian Peninsula: N. amoud sp. nov. from Saudi Arabia, N. marnif sp. nov. and N. samail sp. nov. from Oman. All species descriptions are based on males and females, supported by CO1 barcodes, and accompanied by SEM photographs. While N. amoud sp. nov. is morphologically and genetically similar to N. subtilissima (and to the known African species, of which no CO1 barcodes are available), the two new Omani species are morphologically very distinct. Intraspecific genetic (K2P) distances are partly very high, in particular in N. amoud sp. nov. (up to 17%) and N. marnif sp. nov. (up to 13%). An exploratory species delimitation analysis suggests that these two nominal species might in fact represent several cryptic species each. No corresponding morphological variation was detected.

Luteimonas salinilitoris sp. nov., isolated from the shore soil of saline lake in Tibet of China

Five aerobic, Gram-stain-negative bacterial strains, designated as C3-2-a3T, B3-2-R+30, C3-2-a4, C3-2-M3 and C3-2-M8, were isolated from the coastal soil of LungmuCo Lake in the Tibet Autonomous Region, PR China. Phylogenetic analyses based on 16S rRNA genes and genomes indicated that these isolates belonged to the genus Luteimonas and showed a high similarity to Luteimonas suaedae LNNU 24178T (99.01%), Luteimonas endophytica RD2P54T (98.80%) and Luteimonas salinisoli SJ-92T (97.67%). The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strain C3-2-a3T and related reference strains Luteimonas suaedae LNNU 24178T, Luteimonas endophytica RD2P54T and Luteimonas salinisoli SJ-92T were 91.89, 83.11 and 83.86% and 46.90, 26.90 and 28.20%, respectively. All values were below the thresholds for delineating species, supporting their classification as novel species of the genus Luteimonas. The genomic DNA G+C content of strains C3-2-a3T was 68.39%. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and two unidentified phospholipids. The predominant respiratory quinone was ubiquinone-8 (Q-8), aligning with the characteristics of members of the genus Luteimonas. The major fatty acids (>10.0%) of strain C3-2-a3T were identified as iso-C11 :  0, iso-C15 :  0, iso-C16 : 0 and iso-C17 : 1  ω9c. Based on the results of phenotypic, physiological, chemotaxonomic and genotypic characterizations, we propose that the isolates represent a novel species of genus Luteimonas, for which the name Luteimonas salinilitoris sp. nov is proposed. The type strain is C3-2-a3T (=CGMCC 1.14507T=KCTC 8642T).

Lentilactobacillus terminaliae sp. nov., isolated from tree bark (Terminalia ivorensis Chev.) and its antioxidant activity

A Gram-stain-positive, facultatively anaerobic, rod-shaped strain, designated SPB1-3T, was isolated from tree bark. This strain exhibited heterofermentative production of dl-lactic acid from glucose. Optimal growth was observed at 25-40 °C, pH 4.0-7.0, and in the presence of 3% (w/v) NaCl. The cell wall peptidoglycan contained lysine and aspartic acid. The predominant fatty acids identified were C16:0 and the Summed feature 7 (C19 :1  ω7c/C19:1  ω6c and/or C19:1  ω6c/ω7c/19cy). The polar lipid profile included phosphatidylglycerol, diphosphatidylglycerol and phosphatidylinositol, along with two unidentified phospholipids, two unidentified amino lipids and two unidentified lipids. Phylogenetic analysis based on 16S rRNA gene sequences positioned strain SPB1-3T within the genus Lentilactobacillus, showing a close relation to Lentilactobacillus kosonis NBRC 111893T (99.86%) and Lentilactobacillus curieae CCTCC M 2011381T (98.65%). The whole genome of strain SPB1-3T comprised 1 932 998 base pairs with 1955 coding genes and a DNA G+C content of 37.8%. Digital DNA-DNA hybridization between strain SPB1-3T and closely related type strains ranged from 19.50 to 27.20%. The average nucleotide identity ranged from 84.21 to 85.56%, and the average amino acid identity ranged from 57.25 to 85.99%, both falling below the established thresholds for species delineation. Strain SPB1-3T was clearly distinguishable from related Lentilactobacillus species based on its phenotypic and chemotaxonomic characteristics, 16S rRNA gene sequence similarity and whole genome analysis. Additionally, the strain exhibited radical scavenging activity at 66.92% and demonstrated 82.32% inhibition in the tyrosinase inhibitory assay. These findings support the classification of strain SPB1-3T as a novel species within the genus Lentilactobacillus, for which the name Lentilactobacillus terminaliae sp. nov. is proposed. The type strain is SPB1-3T (=JCM 35081T=TISTR 10005T).

Flavobacterium arundinis sp. nov., Flavobacterium calami sp. nov., Flavobacterium helocola sp. nov. and Flavobacterium flavipallidum sp. nov., isolated from stagnant water in a clump of Phragmites japonica Steud

Four novel bacterial strains were isolated from stagnant water in a clump of Phragmites japonica Steud. The four Gram-negative, facultatively anaerobic, rod-shaped, non-motile and yellow-coloured strains were designated as DGU11T, DGU38T, DGU41T and DGU99T. The four novel strains exhibited 16S rRNA gene similarities with their closest type strains, ranging from 95.7 to 98.7%, average nucleotide identity values from 75.3 to 95.6% and digital DNA-DNA hybridization values between 17.9 and 59.6%. The cells of strain DGU11T were non-motile and grew at 10-30°C (optimum 25 °C), a pH range of 4.0-12.0 (optimum 9.0) and in the presence of 0-1.0% sodium chloride (NaCl) (optimum 0%). The cells of strain DGU38T were non-motile and grew at 10-35°C (optimum 30 °C), a pH range of 4.0-8.0 (optimum 7.0) and at 0 -2.0% NaCl (optimum 0%). The cells of strain DGU41T were non-motile and grew at 15-50°C (optimum 30 °C), a pH range of 6.0-9.0 (optimum 7.0) and in the presence of 0% NaCl (optimum 0%). The cells of strain DGU99T were non-motile and grew at 15-35°C (optimum 25 °C), a pH range of 6.0-12.0 (optimum 9.0) and in the presence of 0 -2.0% NaCl (optimum 0%). The major fatty acid composition of the four novel strains was iso-C15:0 and C16:1  ω7c/C16:1  ω6c, which is similar to other Flavobacterium species. The proposed names of the novel strains are Flavobacterium arundinis sp. nov. (type strain DGU11T=KACC 23722T=TBRC 19004T), Flavobacterium calami sp. nov. (type strain DGU38T=KACC 23723T=TBRC 19005T), Flavobacterium helocola sp. nov. (type strain DGU41T=KACC 23724T=TBRC 19006T) and Flavobacterium flavipallidum sp. nov. (type strain DGU99T=KACC 23725T=TBRC 19007T).

Pseudobensingtonia carpini sp. nov., a novel yeast species isolated from plant leaves in China

Two novel yeast strains, NYNU 236247 and NYNU 23523, were isolated from the leaves of Carpinus turczaninowii Hance, collected in the Tianchi Mountain National Forest Park, Henan Province, central China. Phylogenetic analysis of the D1/D2 domain of the large subunit rRNA gene and the internal transcribed spacer (ITS) region revealed the closest relatives of the strains are three described Pseudobensingtonia species: Ps. fusiformis, Ps. musae and Ps. ingoldii. The novel species differed from the type strains of these three species by 12 to 22 nucleotide substitutions and 1 gap (~2.0-4.0%) in the D1/D2 domain and by 78 to 100 nucleotide mismatches (~12.0-16%) in the ITS region. Physiologically, the novel species differs from Ps. fusiformis and Ps. musae in its ability to assimilate dl-lactate and melezitose and from Ps. ingoldii by its inability to assimilate melibiose, soluble starch and ethanol. Pseudobensingtonia carpini sp. nov. is proposed for those two strains, with the holotype designated as GDMCC 2.483T (MycoBank MB 857072).

Chionosphaera pinicorticola sp. nov., a novel basidiomycetous yeast species isolated from pine tree bark in Gyeongju, South Korea

A novel yeast species, isolated from the bark of pine trees in Gyeongju, South Korea, and designated as KCTC 37304T (ex-type KACC 410729), is characterized by its genetic, morphological and physiological properties. Molecular phylogenetic analysis involving the D1/D2 domain of the 26S LSU rRNA gene and the internal transcribed spacer (ITS) region confirms that it belongs to the genus Chionosphaera. In comparison to Chionosphaera cuniculicola CBS:10065, the type strain of its closest relative, KCTC 37304T exhibits 8 nucleotide substitutions (~2.07%) in the D1/D2 domain and 54 substitutions (~8.47%) in the ITS region. Morphologically, cells of KCTC 37304T are globose to ovoid, which distinguishes them from the cylindrical cells of C. cuniculicola. Physiologically, KCTC 37304T does not assimilate methanol or ethanol but can utilize succinate and xylitol, further differentiating it from C. cuniculicola. Based on these distinctive genetic, morphological and physiological features, we propose the new species Chionosphaera pinicorticola sp. nov., with KCTC 37304T (ex-type strain KACC 410729) designated as the holotype.