Genome Of Strain Research Articles

Genomes of novel Serratia strains from suburban soil.

Here, we present genomes of three strains of Serratia initially isolated from suburban soil-one strain of S. ureilytica and two strains of S. quinivorans-resistant to multiple classes of antibiotics. This expands the genomic sampling of a group relevant to the ecosystem and human health.

Methanochimaera problematica gen. nov., sp. nov., a novel methanoarchaeon isolated from cold seep sediment and reclassification of Methanomicrobium antiquum as Methanoeremita antiquus gen. nov., comb. nov.

A hydrogenotrophic methanoarchaeon, designated strain FWC-SCC4T, was isolated from cold seep sediment of Four-Way Closure Ridge, offshore southwestern Taiwan. Strain FWC-SCC4Tutilizes H2/CO2 or formate, but not acetate, secondary alcohols, methylamines, methanol or ethanol for growth and methane production. Yeast extract is required for growth. The cell morphology is coccoid, with a diameter of 0.8-1.2 µm, and the cell envelope is composed of S-layer protein with Mr about 137.00 kDa. Cells possess multiple flagella and usually occur singly. Strain FWC-SCC4T grows at a temperature range of 20-40 °C (optimum 37 °C) and a pH range of 5.4-7.2 (optimum 7.0). The NaCl range for growth is 0-0.86 M (optimum 0.09 M). The result of phylogenetic analysis of 16S rRNA gene sequences indicates that the most closely related species are Methanoplanus limicola M3T and Methanoplanus endosymbiosus MC1T, with similarities of 95.95 and 95.63%, respectively. The G+C content of the genomic DNA is 40.3 mol%. The overall genome-relatedness indexes (OGRIs) and concatenated ribosomal protein (RBP) phylogenic analysis indicate that strain FWC-SCC4T is a novel lineage of Methanomicrobiaceae. In addition to strain FWC-SCC4T, the differences between Methanomicrobium antiquum MobHT and Methanomicrobium mobile BPT demonstrated by comparative analysis of genomic G+C content and phylogenetic analysis with non-type strain genomes are enough to support the establishment of a novel genus. In conclusion, strain FWC-SCC4T (BCRC AR10058T= NBRC 114595T) is proposed as the type strain of Methanochimaera problematica gen. nov., sp. nov., and Methanoeremita antiquus gen. nov., comb. nov. is proposed as the new name for Methanomicrobium antiquum MobHT (=DSM 21220T= NBRC 104160T).

Jannaschia ovalis sp. nov., a marine bacterium isolated from a tidal flat sediment in the Republic of Korea.

A Gram-stain-negative, non-motile, aerobic, pale-yellow coloured and oval-shaped bacterium designated GRR-S6-38T was isolated from a tidal flat sediment that collected from Garorim Bay of the Yellow Sea, Republic of Korea. Strain GRR-S6-38T grew at 15-40°C (optimum, 30°C) at pH 6-9 (optimum, pH 7) and at 2-6% (w/v) NaCl (optimum, 2% NaCl). Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain GRR-S6-38T was closely related to those of J. seosinensis CL-SP26T (98.1%), J. helgolandensis DSM 14858T (97.4%), J. rubra CECT 5088T (97.4%), J. faecimaris DSM 100420T (97.4%), J. marina SHC163T (97.3%), J. donghaensis CECT 7802T (97.2%) and J. pohangensis DSM 19073T (97.1%). The average nucleotide identity and digital DNA-DNA hybridization value between GRR-S6-38T and related type strains were 71.47-78.59% and 17.80-21.40%. Strain GRR-S6-38T was characterized as having Q-10 as the predominant respiratory quinone and the major principle fatty acids (> 10%) were SF 8 (C18:1 ω7c/C18:1 ω6c, 39.3%), C19:0 ω8c cyclo (13.2%) and C18:1 ω7c 11-methyl (10.6%). The polar lipids consisted of diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, an unidentified lipid, two unidentified aminolipids and two unidentified phospholipids. The assembled genome of strain GRR-S6-38T has a total length of 3.32 Mbp, and a G + C content is 69.98%. Based on the polyphasic taxonomic evidence presented in this study, GRR-S6-38T is regarded to represent a novel species within the genus Jannaschia, for which name Jannaschia ovalis sp. nov. is proposed. The type strain is GRR-S6-38T (= KCTC 82518 = KACC 22240 = JCM 36187).

Genomic Characterization and Comparative Genomic Analysis of the Foodborne Burkholderia gladioli pv. cocovenenans.

The Burkholderia gladioli pv. cocovenenans (B. cocovenenans) has been linked to fatal food poisoning cases, which could produce the deadly toxin of bongkrekic acid (BA). However, genomic characterization and toxin production pathways of B. cocovenenans strains remain elusive. This study aimed to explore the BA-producing ability associated with the evolution of the bon gene cluster and to analyze the intraspecies genomic diversity and phylogenetic relationships of B. gladioli based on the 17 genomes of B. cocovenenans strains isolated from Shenzhen City, China. Genome sequencing results suggested that the genome sizes of these B. cocovenenans strains were mostly approximately 8 Mb, with a GC content of approximately 68%. The evolutionary tree analysis of the whole-genome sequences showed that significant divergences and distinct cluster were exhibited among these B. cocovenenans strains. Comparative genomic analysis indicated that the genomes of strains 2020051, 2021031, and 2021067 contained the complete and entire bon gene cluster, supporting that these strains displayed obviously BA-producing ability. The genomes of strains 2021028 and 2020041 lacked the entire bon gene cluster. However, the genomes of strains 2021037, 2021024, 2021035, and 2021031 exhibited disruptions in their bon gene clusters. This finding indicated the loss of specific genes within the cluster, suggesting a reduced capability for BA production in these strains. The present results indicated that the bon gene cluster in the genome played a key role in the toxin BA biosynthesis of different B. cocovenenans strains. This study provided a comprehensive understanding of the relationship between genomic diversity and BA production of this lethal foodborne pathovar, which will potentially contribute to the risk identification and food poisoning outbreak prevention of B. cocovenenans.

Molecular Genetic Characteristics of the Mutant Strain B-162/2 of the Bacteria <i>Pseudomonas chlororaphis</i> subsp. <i>aurantiaca</i>

The production of microorganisms that produce biologically active compounds for agriculture, the chemical, veterinary and pharmaceutical industries as well as for environmental protection continues to be an important direction of microbial biotechnology. One of the most effective approaches to the production of producers is chemical mutagenesis, which, in combination with the right breeding strategy, makes it possible to obtain highly productive strains. A significant disadvantage of chemical mutagenesis is the large number of induced mutations in the genomes of mutant strains, which makes it difficult to identify genes and, accordingly, biosynthetic pathways involved in the production of a given compound. The solution to this problem is modern technologies of genome sequencing and analysis, which make it possible to identify new genes and unknown biochemical pathways involved in the formation of biologically active compounds. The aim of the work was to analyse the genome of the mutant strain B-162/2 of the bacterium Pseudomonas chlororaphis subsp. aurantiaca, which is capable of increased production of biologically active compounds of the phenazine series and is resistant to hydrogen peroxide. When analysing the genome of strain B-162/2 in full size, 6482 coding sequences and 64 coding RNA sequences were identified. Comparison of the genome of the B-162/2 strain with the genome of the wild type B-162 allowed the identification of 39 mutations, 5 of which are localised in intergenic regions, and 34 affected coding sequences. Of the mutations detected, 14 led to a radical amino acid substitution in the proteins and 2 led to the formation of premature stop codons (methyl group sensor and MFS-type transporter). Several substitutions with high values of the Grantham coefficient were found, which could possibly lead to a change in the activity of the proteins concerned. The presence of three regions with phage genes in the genome of the B-162/2 strain was detected.

First Detection of a Novel Posavirus 2 Strain Identified from Pigs in China

Porcine stool-associated RNA virus (Posavirus) is an unclassified virus with sequence similarity to viruses in the order of Picornaviridae. In China, lineage 1 Posavirus (Posavirus 1) has been circulating in the field since its initial emergence in 2014 however no other lineages have been reported. To investigate the genetic diversity of Posavirus in China, 1200 diarrheic samples were collected from pigs in China. Following high-throughput and Sanger sequencing, one complete genome sequence of a Posavirus (designated SC01) strain was obtained. The genome of SC01 strain was 10217 nucleotides in length and encoded a polyprotein of 3346 amino acids. Genome comparative analysis revealed that SC01 shared 85.6% nucleotide similarity to Posavirus 2 strains, but only 35.2–58.0% sequence identity with Posavirus 1 and 3–12 strains. Phylogenetic analysis showed that the SC01 was classified in Posavirus 2 and clustered into a separate branch with the American Posavirus 2 isolates, indicating that the SC01 is a Posavirus 2 strain. Notably, a novel 1-amino acid deletion was observed in polyprotein at amino acid position 147. This is the first report of the presence of Posavirus 2 in China, and the genomic data of SC01 provides insights into the genetic diversity and evolution of Posavirus in the region.

Comparative analysis of European subtype tick-borne encephalitis virus strains isolated from patients from Eastern Siberia and Eastern and Northern Europe

Background. Isolation of strains from tick-borne encephalitis (TBE) patients proved that the European subtype tick-borne encephalitis virus (TBEV-Eur) in Siberia is involved in regional human infectious pathology and causes a clinical picture similar to Western TBE. However, a comparative analysis of the genomes of TBEV-Eur strains isolated from TBE patients in Eastern Siberia and Europe has not been carried out.The aim. Genome comparative analysis and search for virulence determinants in TBEV-Eur strains isolated from patients in Eastern Siberia and Northern and Eastern Europe.Materials and methods. In current work, TBEV-Eur strain 1G-98 from the collection of Scientific Сentre for Family Health and Human Reproduction Problems (GenBank Acc. No. KY069119) was used. The analysis also included all complete genome sequences of TBEV-Eur strains from patients submitted in GenBank database at the time the study began. Complete genome sequencing of strain 1G-98 was performed using the Sanger method. The virulence of the strain was assessed by intracerebral and subcutaneous infection of laboratory mice.Results. It has been shown that, according to the coding region of the genomes, the level of differences between TBEV-Eur strains from Siberia does not exceed the previously established maximum for this subtype of 3.1 %. The strain 1G-98, isolated from the blood of TBE patient from the Irkutsk region demonstrated high cerebral and peripheral activity. In this strain, D67G mutation in E protein DII domain was revealed, which could potentially be associated with virulence, and a long deletion in the variable part of the 3’-noncoding genome region, comparable in length to the highly virulent strain Hypr from Europe was found.Conclusions. For the first time, a comparative analysis of the genomes of TBEV-Eur strains from TBE patients from the Asian part of Russia and Europe was carried out showing their genetic similarity, and potential virulence determinants were identified. Key words: tick-borne encephalitis virus, European subtype, genome, amino acid sequence, virulence determinants

Complete genome sequence of Bacillus pumilus NWMCC0302, a strain for degrading bovine blood

BackgroundDirectly discharging livestock and poultry slaughter blood without proper treatment can cause severe ecological damage. Exploring the use of microorganisms to break down waste blood into smaller molecules such as peptides and amino acids, as well as investigating the possibility of transforming these small molecules into water-soluble fertilizers containing amino acids, holds significant research value in the comprehensive utilization of livestock and poultry blood.ResultsIn this study, a single strain of Bacillus pumilus NWMCC0302, which has effectively degraded bovine blood, was isolated from abattoir blood sludge using casein agar plates and Columbia blood agar plates. The degradation test was carried out using bovine raw blood as a nitrogen source in the medium, and the results showed that the strain degraded 53.83% of bovine blood under optimal degradation conditions. The whole genome sequencing of Bacillus pumilus NWMCC0302 was conducted using the second-generation DNBSEQ platform and the third-generation PacBio platform, employing high-throughput sequencing technology. The size of the strain's entire genome was determined to be 3 868 814 bp with a G-C content of 41.63%. The total gene length accounted for 88.98% of the genome length at 3 442 341 bp and encoded 4 113 genes. The strain contained 79 tRNAs, 24 rRNAs, 7 sRNAs, and 296 repetitive sequences. The gene data obtained from sequencing were also functionally annotated using the COG, KEGG, and VFDB databases. In the COG database, 310 genes were involved in amino acid transport and metabolism, including 10 catabolic proteins related to COGs. In the KEGG database, were 201 genes involved in amino acid metabolism pathways, including 8 genes in nitrogen metabolism pathways and 2 genes in oxidative pathways. The VFDB database contains two lysostaphin genes and one serine protease-hydrolyzed ClpP gene.ConclusionsIn summary, Bacillus pumilus NWMCC0302 was screened for its efficient ability to degrade bovine blood. Additionally, the genetic information of Bacillus pumilus NWMCC0302 was revealed at the genetic level, providing a feasible experimental method for applying this strain to the degradation of blood from slaughtered livestock and poultry. Moreover, it is a potential functional strain for producing amino acid-containing water-soluble fertilisers.

Isolation, Identification, and Molecular Evolutionary Analysis of Infectious Hematopoietic Necrosis Virus (IHNV) from Farmed Rainbow Trout in Southwest China

IHNV troubled the salmon breeding industry in China for years, and it often causes large-scale deaths. To study the disease characteristics of IHNV and its epidemiology in China， this study isolated and sequenced the Whole genome of an IHNV strain (IHNV-SCCD) (GenBank No： OQ801357) from farmed diseased rainbow trout in Chengdu and compared 99 IHNV strains from China by mega.11. The IHNV-SCCD strain was isolated by using EPC cells. The complete genome sequence was determined and deposited in the NCBI database. Phylogenetic analysis showed that IHNV-SCCD belongs to the typical J gene group, recently with Sichuan strains. Except for BjLL strain and LN12-17 strain, the remaining 98 strains followed a single evolutionary path. Note that IHNV in Liaoning province is the fastest evolutionary. In addition to the geographical differences, the Xinjiang strains were closely related to the Yunnan strains, and some strains from Beijing were closely related to some strains from Sichuan. There were two evolutionary branches in Gansu and Qinghai; QH17, isolated from Qinghai, was most closely related to SX1704 from Shaanxi. These results suggest that the prevalence of IHNV in China was extremely wide, and the evolution rate was fast. It is necessary to strengthen the monitoring and prevention methods.

Genomic determinants in pathogenicity of SARS-CoV-2 versa common cold coronaviruses

Determination of the different short oligonucleotide features in the full genome of fatal and mild coronavirus strains can show the researchers how these viruses evolved and became virulent strains. To this aim, at first, in the full genome of all coronavirus strains included in this study, the observed and expected frequency of dinucleotide to hexanucleotide was obtained using Markov method. Then odds ratio (observed/expected abundances) of short oligonucleotide was computed and considered as the raw data (features). Finally, ten distinct weighting algorithms approaches (Information Gain, Information Gain Ratio, Rule, Deviation, Chi Squared, Gini Index, Uncertainty, Relief, Support Vector Machine (SVM), and PCA) was employed on the features to identify oligonucleotide distribution differences across the full genome of SARS-related viruses compared to common cold coronaviruses. Totally among 5440 features (16 dinucleotides, 64 trinucleotides, 256 tetra nucleotides, 1024 penta-nucleotides, and 4096 Hexa-nucleotides), CC, CCA, CCAC, ACCAC, and CACCAC motifs were selected by 80 -90% of all weighting algorithms models to distinguish virulent strains from mild coronaviruses. These remarkable oligonucleotides might point toward the existence of some particular RNA elements that might be involved in viral virulence and thus can be targeted for viral treatment in the future.

Characterization, Genome Sequencing, and Development of a Rapid PCR Identification Primer for Fusarium oxysporum f. sp. crocus, a New forma specialis Causing Saffron Corm Rot.

Saffron corm rot (SCR), the most serious disease affecting saffron, has been confirmed to be caused by Fusarium oxysporum in previous studies. Compared to other fungal species, F. oxysporum exhibits host specialization, a special phenomenon associated with the secreted in xylem (SIX) genes. This study examined the pathogenicity specialization of F. oxysporum isolated from saffron corms with SCR disease. The results showed that this F. oxysporum strain was strongly pathogenic to saffron corms, causing SCR; weakly pathogenic to the corms of freesia, which is in the Iridaceae family along with saffron; and not pathogenic to watermelon, melon, and tomato. Other formae speciales of F. oxysporum were not pathogenic to saffron corms. This suggests that F. oxysporum saffron strains exhibit obvious pathogenicity specialization for Iridaceae spp. Subsequently, the F. oxysporum saffron strain (XHH35) genome was sequenced, and a comparative genomics study of XHH35 and three other formae speciales was conducted using OrthoVenn3. XHH35 contained 90 specific genes absent in the other three formae speciales. These genes are involved in certain key biological processes and molecular functions. Based on BLAST homology searching, the F. oxysporum saffron strain (XHH35) genome was predicted to contain seven SIX genes (SIX 4, SIX 6, SIX 7, SIX 10, SIX 11, SIX 12, and SIX 14) highly homologous to F. oxysporum f. sp. lycopersici, which was verified using polymerase chain reaction (PCR) amplification. The corresponding individual phylogenetic tree indicated that the F. oxysporum saffron strain (XHH35) showed a separate branch with different formae speciales. This study is the first-ever report of F. oxysporum f. sp. crocus, a new forma specialis. Based on the specificity of its SIX genes, the SIX 10 gene was selected to further establish a rapid identification technique for F. oxysporum f. sp. crocus, which will be useful in future research.

Etiological characteristics of Brucella melitensis in Henan Province, 2013-2022

Objective: To analyze the genus, drug resistance/virulence and phylogenetic characteristics of Brucella strains isolated from brucellosis surveillance sentinels in Henan Province from 2013 to 2022, and provide baseline data for the surveillance, early warning and outbreak tracing of brucellosis. Methods: Blood samples were collected from patients with Brucella infection for strain isolation, culture and species identification, drug susceptibility test, whole genome sequencing, splicing and assembly, functional/virulence/resistance gene prediction analysis and phylogenetic tree drawing based on single nucleotide polymorphism (SNP). Results: In 36 brucellosis patients, the majority were men (86.11%, 31/36), young adults aged 18-50 (88.89%, 32/36) and farmers/herdsmen (72.22%, 26/36). A total of 36 strains of Brucella melitensis were isolated, and average 1 305 functional proteins of 21 categories were predicted by strain genome; all the strains carried four main virulence factors (pmm, VirB group, BtpA/BtpB, BvrS/BvrR). The drug sensitivity rate was 100.00% to six types of antibiotics including levofloxacin, rifampicin, doxycycline, streptomycin, tetracycline and gentamicin, they showed different resistances to three antibiotics including compound trimethoprim-sulfamethoxazole, ciprofloxacin and ampicillin. The strains carried four types of resistance genes and two clusters of resistance genes, with four combinations of genotypes, the resistance mechanisms included antibiotic degradation/modification enzymes, resistant nodular cell differentiation (RND) efflux pumps, 16S/23S ribosomal rRNA binding site mutations, etc. The number of SNP differed in the genomes of 36 Brucella melitensis strains ranged from 0 to 454 and phylogenetic tree was divided into three major branches, with relative branch distances between 0.000 0 and 0.498 6 for each strain. Conclusions: Human Brucella melitensis strains isolated from surveillance sentinels in Henan from 2013 to 2022 carried multiple virulence and antibiotic resistance genes and had different drug resistance phenotypes. Single nucleotide polymorphism analysis and phylogenetic tree analysis showed significant differences in phylogenetic relationships among different strains.

GCM and gcType in 2024: comprehensive resources for microbial strains and genomic data.

Microbial culture collections play a crucial role in the collection, maintenance, and distribution of quality-assured living microbial strains, along with their associated phenotypic and omics data. To enhance the find-able, accessible, interoperable, and re-usable (FAIR) data utilization of microbial resources, the World Data Center for Microorganisms (WDCM) has developed the Global Catalogue of Microorganisms (GCM) and the Global Catalogue of Type Strains (gcType). These platforms provide interactive interfaces for cataloging the holdings of collections, along with detailed annotations of type strain genomes and curated metadata, including ecosystems, growth conditions, and collection locations. The system maximizes the scientific impact of microbial resources and culture collections through an integrated data mining tool that links strain- and species-related information from various public resources. Currently, the GCM and gcType include 574422 strains from 154 culture collections across 51 countries and regions, along with 25980 genomes from type species. Additionally, 2702655 articles and 103337 patents are integrated with these microbial resources.The system supports microbial taxonomic research and provides evidence for implementing the Nagoya Protocol in the field of microbial resources and their digital sequence information (DSI). Access is freely available at gcm.wdcm.org and gctype.wdcm.org.

Pseudomonas huanghezhanensis sp. nov. and Pseudomonas fjordensis sp. nov., two novel species isolated from seawater of Arctic Kongsfjorden in the Ny-Ålesund area, Svalbard.

Two Gram-stain-negative bacterial strains, BSw22131T and DMSP-1T, were isolated from seawater of Arctic Kongsfjorden in the Ny-Ålesund area, Svalbard. Strains BSw22131T and DMSP-1T were within the genus Pseudomonas and presented 98.1 and 99.8% 16S rRNA gene sequence similarity to Pseudomonas piscicola P50T and Pseudomonas paracarnis V5/DAB/2/5T, respectively. However, the results of multilocus sequence analysis (concatenated 16S rRNA, gyrB, rpoB and rpoD gene sequences) and whole-genome sequence analysis indicated that BSw22131T and DMSP-1T were most closely related to Pseudomonas petrae P2653T and Pseudomonas lactis DSM 29167T, respectively. The genome G+C contents of strains BSw22131T and DMSP-1T were 58.2 and 60.0%, respectively. The two isolates presented digital DNA-DNA hybridization and average nucleotide identity values of less than 70 and 96%, respectively, with type strain genomes of their close relatives. BSw22131T contained summed feature 3 (C16 : 1 ω6c/C16 : 1 ω7c), C16 : 0 and summed feature 8 (C18 : 1 ω6c/C18 : 1 ω7c) as the major cellular fatty acids, whereas DMSP-1T contained an additional C17 : 0-cyclo as the major fatty acid. The major quinones of both strains were Q-9 (57.5-77.2%) and Q-8 (22.8-37.2%), and their major cellular polar lipids were diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. BSw22131T could be differentiated from its related species by positive ornithine decarboxylase, esterase (C8) and l-rhamnose and d-fructose-6-PO4 utilization, whereas DMSP-1T could be differentiated by positive acid phosphatase but negative p-hydroxyphenylacetic acid utilization. The two strains were negative for the reduction of nitrates but contained genes related to dimethylsulfoniopropionate catabolism. The results of the polyphasic taxonomy analysis revealed that strains BSw22131T and DMSP-1T represent two novel species of the genus Pseudomonas, for which the names Pseudomonas huanghezhanensis sp. nov. (type strain BSw22131T = CCTCC AB 2019135T = JCM 36635T = DSM 117336T) and Pseudomonas fjordensis sp. nov. (type strain DMSP-1T = CCTCC AB 2019124T = JCM 36636T = DSM 117337T) are proposed.

Gut heavy metal and antibiotic resistome of humans living in the high Arctic.

Contaminants, such as heavy metals (HMs), accumulate in the Arctic environment and the food web. The diet of the Indigenous Peoples of North Greenland includes locally sourced foods that are central to their nutritional, cultural, and societal health but these foods also contain high concentrations of heavy metals. While bacteria play an essential role in the metabolism of xenobiotics, there are limited studies on the impact of heavy metals on the human gut microbiome, and it is so far unknown if and how Arctic environmental contaminants impact the gut microbes of humans living in and off the Arctic environment. Using a multiomics approach including amplicon, metagenome, and metatranscriptome sequencing, we identified and assembled a near-complete (NC) genome of a mercury-resistant bacterial strain from the human gut microbiome, which expressed genes known to reduce mercury toxicity. At the overall ecological level studied through α- and β-diversity, there was no significant effect of heavy metals on the gut microbiota. Through the assembly of a high number of NC metagenome-assembled genomes (MAGs) of human gut microbes, we observed an almost complete overlap between heavy metal-resistant strains and antibiotic-resistant strains in which resistance genes were all located on the same genetic elements.

Dickeya ananae sp. nov., pectinolytic bacterium isolated from pineapple (Ananas comosus).

Recently, species clustering within Dickeya zeae has been identified as complex, encompassing validly published names, including D. oryzae and D. parazeae, with some strains potentially delineating new species. In this study, genomes of strains isolated from a bacterial heart rot outbreak in pineapple (Ananas comosus var. comosus) on Oahu, Hawaii, along with two strains from pineapple in Malaysia, were sequenced. Orthologous average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values among the sequenced genomes ranged from 98.93-99.9% and 91.8-99.9%, respectively, supporting the classification of seven strains within the same species. Comparisons of ANI and dDDH values between these seven strains and type strains of D. zeae, D. parazeae, and D. oryzae ranged from 94.4-95.9% and 57.2-66.5%, respectively. These values fall below the proposed boundaries for new species designation, supporting the delineation of a novel species. Phylogenetic analyses, including 16S rRNA, gapA, multi-locus sequence analysis (MLSA) of 10 housekeeping genes, whole-genome, and pangenome analyses, were concordant and revealed a distinct monophyletic clade, separating these strains from other members of the D. zeae complex, with D. oryzae as the closest relative. Notably, a nitrogen fixation gene cluster comprising 28 genes, similar to the Klebsiella spp. nitrogenase gene cluster, was found in the genome of the seven pineapple strains. Based on polyphasic approaches, including ANI, dDDH, biochemical, physiological, and phylogenomic analyses, we propose the reclassification in a new species of the five pineapple strains from Hawaii A5391, A5410T, A5611, A6136, and A6137, together with the two pineapple strains from Malaysia CFBP 1272 and CFBP 1278, previously classified as D. zeae. We propose the name Dickeya ananae sp. nov. for this taxon, represented by the type strain A5410T (= ICMP 25020T = LMG 33197T).

Analysis of Straw Degradation and Whole Genome of Acrophialophora multiforma.

Lignin is one of the main components in plants, which can transform value-added bioenergy and chemicals. At the same time, due to the close combination of lignin and hemicellulose in the structure, it becomes a barrier for cellulose utilization. Therefore, the effective degradation of lignin is of great significance for the utilization of these resources. In this study, the lignin degrading ability of Acrophialophora multiforma strain GZUIFR 22.397 was preliminarily investigated through straw degradation experiments and enzyme activity determination. Then, the whole genome of strain A. multiforma GZUIFR 22.397 was sequentially analyzed and annotated through multiple gene function annotation databases to comprehensively evaluate its lignin degrading potential. The results showed that the weight loss of straw reached 5.98 ± 3.95%. Laccase activity was 77.49 ± 2.65 U/L, lignin peroxidase activity was 160.57 ± 29.07 U/L, and manganese peroxidase activity was 294.83 ± 3.77 U/L. The genome of A. multiforma strain GZUIFR 22.397 spans 33.81 megabases and encompasses 9,370 genes. Among these, 6,122 genes have been annotated in the Gene Ontology (GO), 2,286 in the Cluster of Orthologous Groups of proteins (KOG), 2,283 in the Kyoto Encyclopedia of Genes and Genomes (KEGG), and 603 in the Carbohydrate Active enZYmes Database (CAZy). Concurrently, the genome analysis predicted the presence of 9 genes for laccase, 2 genes for lignin peroxidase, and 2 genes for manganese peroxidase. In summary, these results indicated that A. multiforma GZUIFR 22.397 has lignin degrading ability, and laid the foundation for deciphering the molecular mechanism of A. multiforma GZUIFR 22.397 to degrade lignin.

Comparative genomic analysis of two putative novel Idiomarina species from hypersaline miocene deposits

BackgroundHypersaline habitats, as extreme environments, are a great source of well-adapted organisms with unique properties as they have evolved various strategies to cope with these extreme conditions. Bioinformatics and genomic mining may shed light on evolutionary relationships among them. Therefore, the aim of this study was to assess the biodiversity and especially the strategies evolved within the Idiomarina genus, with the primary focus on the taxonomy and genomic adaptations of two novel strains affiliated with Idiomarina genus isolated from unique environment – brines of two Early Miocene salt deposits.ResultsBoth analyzed species belonged to the Idiomarina loihiensis cluster with similarity levels of 16S rRNA gene sequences as high as 99.5% and showed a significant genome size reduction, known characteristic of Idiomarina genomes, though within the genome of Sol25 strain the lowest extent of the carbohydrate utilization genes reduction was observed t among the Idiomarina species. Moreover, the comparative genome analyses indicated that despite both strains being isolated from geographically and geologically similar environments (brines from at least 12 Ma), the species showed higher relatedness to other Idiomarina species than to each other.ConclusionThe present findings highlighted the importance of genomic data in resolving taxonomic uncertainties and understanding of adaptation strategies of extremophiles. Geographic isolation likely contributed to population divergence of the Idiomarina genus, and the recent study offered insights into biogeographic patterns and allopatric speciation of this bacterial group.

Whole-genome sequencing and assessment of a novel protein- and gossypol-degrading Bacillus subtilis strain isolated from intestinal digesta of Tibetan Pigs

BackgroundWith the rapid development of animal husbandry, the demand for protein feed resources is increasing. Cottonseed meal (CSM) and soybean meal (SBM) are rich sources of protein. However, their application is limited due to the existence of anti-nutrients, which can be harmful to the digestion and absorption. A strain of Bacillus subtilis (Mafic-Y7) was isolated from digesta of intestines of Tibetan pigs. The strain showed high protease activity, which helps in degrading proteinic anti-nutritional factors in grain meal and in vitro degradation of free gossypol. In order to better understand this isolated strain, whole genome of Mafic-Y7 strain was sequenced and analyzed. Different effects on various grain meals were identified.ResultThe GC-depth Poisson distributions showed no bias suggesting high-quality genome assembly of Mafic-Y7. The whole genome sequencing showed that one chromosome with 4,248,845 base pairs(bp)and the genes total length with 3,736,524 bp was predicted in Mafic-Y7. Additionally, Mafic-Y7 possessed 4,254 protein-coding genes, and several protease genes were annotated by aligning them with databases. There are 55 protease genes, one phytase gene and one laccase gene were annotated in the gene sequence of Mafic-Y7. The average nucleotide identity between Mafic-Y7 and the GCA-000009045.1 homologous genome was 0.9938, suggesting a close genetic relationship between them at the species level. Compared with the closest four whole genomes, Mafic-Y7 was annotated the most abundant of protease genes (55 genes). The fermentation supernatant of Mafic-Y7 could increase the content of small peptides, water-soluble proteins, and acid-soluble proteins in vitro by 411%, 281% and 317% in SBM and 420%, 257% and 338% in CSM. After fermentation in grain meal by Mafic-Y7, the degradation rate of anti-nutritional factors in SBM, such as trypsin inhibitor, glycinin, and β-conglycinin was greater than 70%, and lectin was greater than 30%. The degradation rates of anti-nutritional factors in CSM, such as gossypol and phytic acid, were 82% and 26%, respectively.

Halosquirtibacter laminarini gen. nov., sp. nov. and Halosquirtibacter xylanolyticus sp. nov., marine anaerobic laminarin and xylan degraders in the phylum Bacteroidota

The bacterial group of the phylum Bacteroidota greatly contributes to the global carbon cycle in marine ecosystems through its specialized ability to degrade marine polysaccharides. In this study, it is proposed that two novel facultative anaerobic strains, DS1-an-13321T and DS1-an-2312T, which were isolated from a sea squirt, represent a novel genus, Halosquirtibacter, with two novel species in the family Prolixibacteraceae. The 16S rRNA sequence similarities of these two strains were 91.26% and 91.37%, respectively, against Puteibacter caeruleilacunae JC036T, which is the closest recognized neighbor. The complete genomes of strains DS1-an-13321T and DS1-an-2312T each consisted of a single circular chromosome with a size of 4.47 and 5.19 Mb, respectively. The average amino acid identity and the percentage of conserved proteins against the type species of the genera in the family Prolixibacteraceae ranged from 48.33 to 52.35% and 28.34–37.37%, respectively, which are lower than the threshold for genus demarcation. Strains DS1-an-13321T and DS1-an-2312T could grow on galactose, glucose, maltose, lactose, sucrose, laminarin, and starch, and only DS1-an-2312T could grow on xylose and xylan under fermentation conditions. These strains produced acetic acid and propionic acid as the major fermentation products. Genome mining of the genomes of the two strains revealed 27 and 34 polysaccharide utilization loci, which included 155 and 249 carbohydrate-active enzymes (CAZymes), covering 57 and 65 CAZymes families, respectively. The laminarin-degrading enzymes in both strains were cell-associated, and showed exo-hydrolytic activity releasing glucose as a major product. The xylan-degrading enzymes of strain DS1-an-2312T was also cell-associated, and had endo-hydrolytic activities, releasing xylotriose and xylotetraose as major products. The evidence from phenotypic, biochemical, chemotaxonomic, and genomic characteristics supported the proposal of a novel genus with two novel species in the family Prolixibacteraceae, for which the names Halosquirtibacter laminarini gen. nov., sp. nov. and Halosquirtibacter xylanolyticus sp. nov. are proposed. The type strain of Halosquirtibacter laminarini is DS1-an-13321T (= KCTC 25031T = DSM 115329T) and the type strain of Halosquirtibacter xylanolyticus is DS1-an-2312T (= KCTC 25032T = DSM 115328T).