Paracoccus benzoatiresistens sp. nov., a benzoate resistance and selenite reduction bacterium isolated from wetland.

A Gram-stain-negative, aerobic, non-motile, catalase- and oxidase-positive, pale orange, rod-shaped strain EF6T, was isolated from a natural wetland reserve in Hebei province, China. The strain grew at 25-37 °C (optimum, 30 °C), pH 5-9 (optimum, pH 7), and in the presence of 1.0-4.0% (w/v) NaCl (optimum, 2%). A phylogenetic analysis based on 16S rRNA gene sequence revealed that strain EF6T belongs to the genus Paracoccus, and the closest members were Paracoccus shandongensis wg2T with 98.1% similarity, Paracoccus fontiphilus MVW-1 T (97.9%), Paracoccus everestensis S8-55 T (97.7%), Paracoccus subflavus GY0581T (97.6%), Paracoccus sediminis CMB17T (97.3%), Paracoccus caeni MJ17T (97.0%), and Paracoccus angustae E6T (97.0%). The genome size of strain EF6T was 4.88 Mb, and the DNA G + C content was 65.3%. The digital DNA-DNA hybridization, average nucleotide identity, and average amino acid identity values between strain EF6T and the reference strains were all below the threshold limit for species delineation (< 32.8%, < 88.0%, and < 86.7%, respectively). The major fatty acids (≥ 5.0%) were summed feature 8 (86.3%, C18:1 ω6c and/or C18:1 ω7c) and C18:1 (5.0%) and the only isoprenoid quinone was Q-10. The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, two unidentified glycolipids, five unidentified phospholipids, and an unidentified aminolipid. Strain EF6T displays notable resistance to benzoate and selenite, with higher tolerance levels (25 g/L for benzoate and 150 mM for selenite) compared to the closely related species. Genomic analysis identified six benzoate resistance genes (acdA, pcaF, fadA, pcaC, purB, and catA) and twenty selenite resistance and reduction-related genes (iscR, ssuB, ssuD, selA, selD and so on). Additionally, EF6T possesses unique genes (catA, ssuB, and ssuC) absent in the closely related species for benzoate and selenite resistance. Its robust resistance to benzoate and selenite, coupled with its genomic makeup, make EF6T a promising candidate for the remediation of both organic and inorganic pollutants. It is worth noting that the specific resistance phenotypes described above were not reported in other novel species in Paracoccus. Based on the results of biochemical, physiological, phylogenetic, and chemotaxonomic analyses, combined with comparisons of the 16S rRNA gene sequence and the whole genome sequence, strain EF6T is considered to represent a novel species of the genus Paracoccus within the family Rhodobacteraceae, for which the name Paracoccus benzoatiresistens sp. nov. is proposed. The type strain is EF6T (= GDMCC 1.3400 T = JCM 35642 T = MCCC 1K08702T).

Enhanced Production of High-Value Porphyrin Compound Heme by Metabolic Engineering Modification and Mixotrophic Cultivation of Synechocystis sp. PCC6803.

Heme, as an essential cofactor and source of iron for cells, holds great promise in various areas, e.g., food and medicine. In this study, the model cyanobacteria Synechocystis sp. PCC6803 was used as a host for heme synthesis. The heme synthesis pathway and its competitive pathway were modified to obtain an engineered cyanobacteria with high heme production, and the total heme production of Synechocystis sp. PCC6803 was further enhanced by the optimization of the culture conditions and the enhancement of mixotrophic ability. The co-expression of hemC, hemF, hemH, and the knockout of pcyA, a key gene in the heme catabolic pathway, resulted in a 3.83-fold increase in the heme production of the wild type, while the knockout of chlH, a gene encoding a Mg-chelatase subunit and the key enzyme of the chlorophyll synthesis pathway, resulted in a 7.96-fold increase in the heme production of the wild type; further increased to 2.05 mg/L, its heme production was 10.25-fold that of the wild type under optimized mixotrophic culture conditions. Synechocystis sp. PCC6803 has shown great potential as a cell factory for photosynthetic carbon sequestration for heme production. This study provides novel engineering targets and research directions for constructing microbial cell factories for efficient heme production.

Mariniradius sediminis sp. nov., a multi-xenobiotics degrading genes harbouring bacterium isolated from sediment of river.

A Gram-stain-negative, strictly aerobic, non-motile, catalase- and oxidase-positive, pink and rod-shaped strain, designated RY-2T, was isolated from sediment of Fuyang River located in Wuqiang County, Hengshui City, Hebei Province, PR China. The strain grew at 25-45 °C (optimum, 37 °C), pH 7.0-8.0 (optimum, pH 7.0) and in the presence of 0-1.5 % (w/v) NaCl (optimum, 1 %). From the phylogenetic analysis of the 16S rRNA gene sequence, strain RY-2T was affiliated to the genus Mariniradius, and had the highest 16S rRNA gene sequence similarity to Mariniradius saccharolyticus JCM 17389T (98.3 %) and the similarity values between strain RY-2T and other type strains was all below 89.3 %. The genome size of strain RY-2T was 4.75 Mb and the DNA G+C content was 46.6 %. Values of digital DNA-DNA hybridization and average nucleotide identity between strain RY-2T and the reference strain were 63.2 and 95.5 %, respectively. The major fatty acids (≥5.0 %) were iso-C15 : 0 (37.9 %), summed feature 9 (8.4 %, iso-C17 : 1 ω9c and/or C16 : 010-methyl), anteiso-C15 : 0 (8.2 %), iso-C17 : 0 3-OH (7.6 %) and summed feature 4 (5.2 %, iso-C17 : 1 I and/or anteiso-C17 : 1 B) and its sole menaquinone was MK-7. The polar lipids consisted of phosphatidylethanolamine, an unknown phosphoglycolipid, an unidentified phospholipid, two unidentified aminolipids, three unidentified glycolipids and nine unidentified lipids. Based on the results of biochemical, physiological, phylogenomic and chemotaxonomic analyses, strain RY-2T is considered to represent a novel species of the genus Mariniradius within the family Cyclobacteriaceae, for which the name Mariniradius sediminis sp. nov. is proposed. The type strain is RY-2T (=GDMCC 1.2781T=JCM 35631T).

Flavihumibacter fluminis sp. nov., a novel thermotolerant bacterium isolated from river silt.

A yellow, Gram-stain-positive, strictly aerobic, thermotolerant, non-motile and rod-shaped bacterial strain, designated RY-1T, was isolated from a silt sample of Fuyang River, Wuqiang County, Hengshui City, Hebei Province, PR China. Cells showed oxidase- and catalase-positive activities. Growth occurred at 20-45 °C (optimum, 37 °C) and pH 6.0-8.0 (optimum, pH 7.0), and in the presence of 0-1.5 % (w/v) NaCl (optimum, 0%). A phylogenetic tree based on 16S rRNA gene sequences revealed that strain RY-1T formed a phylogenetic lineage with Flavihumibacter members within the family Chitinophagaceae. A comparison of 16S rRNA gene sequences showed that strain RY-1T was most closely related to Flavihumibacter cheonanensis WS16T (98.6 %), Flavihumibacter sediminis CJ663T (97.7 %) and Flavihumibacter solisilvae 3-3T (97.6 %). The genome size of strain RY-1T was 4.71 Mb, and the DNA G+C content was 44.3  %. The average nucleotide identity, digital DNA-DNA hybridization and average amino acid identity values between strain RY-1T and reference strains were all lower than the threshold values for species delineation. Strain RY-1T contained menaquinone-7 and iso-C15 : 0, iso-C17 : 0 3-OH and iso-C15 : 1G as the sole respiratory isoprenoid quinone and major cellular fatty acids (≥5 %), respectively. The major polar lipids consisted of phosphatidylethanolamine, three unidentified aminolipids and four unidentified lipids. According to the results of phenotypic, phylogenetic and chemotaxonomic characteristics, strain RY-1T represents a novel species of the genus Flavihumibacter, for which the name Flavihumibacter fluminis sp. nov. is proposed. The type strain is RY-1T (=GDMCC 1.2775T=JCM 34870T).

Flavobacterium potami sp. nov., a multi-metal resistance genes harbouring bacterium isolated from shallow river silt.

Environmental pollution by heavy metals is becoming an increasing problem and has become a matter of great concern due to the adverse effects worldwide. In this study, we report a novel strain of multi-metal resistant bacteria. A Gram-stain-negative, strictly aerobic, non-motile, yellow, rod-shaped strain 17AT, was isolated from the shallow silt of Fuyang River located in Longdian town, Hengshui city, Hebei province, China. Strain 17AT grew at 20-35 °C (optimum, 30 °C), pH 5-10 (optimum, pH 7) and 0-2% (w/v) NaCl (optimum, 1%). Phylogenetic analyses of 16S rRNA gene sequences showed that strain 17AT was closely related to members of the genus Flavobacterium, and had the highest 16S rRNA gene sequence similarity with 'Flavobacterium panacis' DCY106T (97.5%), followed by Flavobacterium johnsoniae subsp. johnsoniae UW101T (97.3%), Flavobacterium cutihirudinis E89T (97.2%), Flavobacterium limi THG-AG6.4T (97.2%), Flavobacterium hibisci THG-HG1.4T (97.2%) and Flavobacterium johnsoniae subsp. aurantiacum DSM 6792T (97.1%). The genome size of strain 17AT was 5.4 Mb and the DNA G + C content was 34.0%. The average nucleotide identity, digital DNA-DNA hybridization and average amino acid identity values among strain 17AT and reference strains were in the ranges of 79.8-86.1%, 24.1-31.4% and 80.5-88.6%, respectively, lower than the threshold values for species delineation. Strain 17AT contained iso-C15:0 and C16:0 3-OH as the predominant fatty acids (≥ 10%). The main isoprenoid quinone of strain 17AT was identified as MK-6. The polar lipids consisted of phosphatidylethanolamine, three unidentified aminolipids, two unidentified aminophospholipids and six unidentified lipids. Comparative genomics analysis between strain 17AT and its reference type strains revealed that there are a number of metal-resistant genes in strain 17AT, which are located in 15 gene clusters responsible for the copper homeostasis, cobalt-zinc-cadmium resistance, copper resistance, and arsenic/antimony resistance, with the copper resistance protein NlpE being unique to 17AT. Combined data from phenotypic, phylogenetic and chemotaxonomic studies demonstrated that strain 17AT is a representative of a novel species within the genus Flavobacterium, for which the name Flavobacterium potami sp. nov. is proposed. The type strain is 17AT (= GDMCC 1.2723T = JCM 34833T).

Combined approach versus single Henry approach for fixation of die-punch distal radius fractures: a retrospective study.

BACKGROUND: Distal radius fracture (DRF) is one of the most common orthopaedic-related traumas. DRF patients with die-punch fractures have a higher risk of loss of reduction, poorer functional outcomes, and increased risk of complications even after open reduction and internal fixation (ORIF). According to the three-column theory, the lunate fossa is an important part of the intermediate column for load bearing. When the distal radius fracture involves the lunate fossa, adequate anatomical reduction can have an important impact on the prognosis of wrist function. Herein, we used the combined volar and dorsal approach, and the dorsal approach was used to assist in bone grafting or dorsal plate fixation in reducing fractures. We compare the combined approach versus the Henry approach for the fixation of die-punch distal radius fractures. METHODS: We reviewed patients who were admitted for surgery for die-punch fractures from January 2016 to June 2021. The patients were followed-up after surgery to measure and evaluate their Gartland-Werley wrist score, wrist range of motion (ROM), and follow-up imaging data. RESULTS: There were 21 patients in the volar locking plate (VLP) group and 10 patients in the combined approach group. The majority of fractures in the VLP and combined approach groups were AO B and C fractures, respectively. The cause of injury and AO fracture classification showed significant differences between the two groups, and there was no difference in age or sex between the two groups. There was no significant difference in ROM between the two groups, but the VLP group presented a better Gartland-Werley score and volar tilt angle, and the combined group presented better maintenance in radial height and articular congruity. CONCLUSIONS: Reduction through the combined palmar and dorsal approach supplemented by bone grafting or dorsal plate fixation is an effective method for the treatment of die-punch distal radius fractures, which provides a new option for the treatment of die-punch fractures.

Magnetic Resonance Imaging Manifestations of Annular Ligament Injuries in Children With Monteggia Fractures.

BACKGROUND: Magnetic resonance imaging (MRI) is commonly performed in children with elbow injuries to visualize soft tissues such as the annular ligament. Herein, we investigated the MRI manifestations of annular ligament injuries in children with Monteggia fractures following attempted closed reduction. METHODS: The clinical and imaging data of 88 children with acute Monteggia fractures treated at our hospital between 2015 and 2019 were analyzed. Clinically and radiographically, 67 patients achieved radiologic reduction of the radial head at the time of MRI, whereas 21 patients had a failed closed reduction. Annular ligament injury and superior radioulnar joint congruency were analyzed qualitatively, and the maximum superior radioulnar joint gap distance was measured. RESULTS: MRI manifestations of annular ligament injury were primarily characterized as varying degrees of annular ligament displacement, as follows: I degree (10 patients), the annular ligament encircled the radial head without displacement; II degree (5 patients), the annular ligament was partially displaced but visibly encircled the radial head at the level of the radial notch; and III degree (73 patients), the annular ligament was completely displaced. In 15 patients with I and II degrees annular ligament injuries, the annular ligament encircled the radial head (maximum superior radioulnar joint gap distance, 1.2±0.3 mm), showing good congruency of the superior radioulnar joint. In 73 patients with III degree annular ligament injury, the annular ligament was displaced and did not encircle the radial head (maximum superior radioulnar joint gap distance, 3.3±2.7 mm; P <0.05), showing good congruency of the superior radioulnar joint in 25 of 73 patients, and significantly poor congruency in 48 of 73 patients ( P <0.05). CONCLUSIONS: Annular ligament injuries in children with Monteggia fractures exhibit different degrees of displacement of the annular ligament. In I and II degree annular ligament injuries, the annular ligament still encircles the radial head. In III degree annular ligament injuries, the annular ligament is displaced away and is no longer around the radial head. Without the annular ligament restraining the radial head, the superior radioulnar joint is more likely to exhibit poor congruency and increased gap distance. LEVEL OF EVIDENCE: Level II.

Lysobacter selenitireducens sp. nov., isolated from river sediment.

A Gram-stain-negative, yellow-pigmented, motile, flagellated and rod-shaped bacterium, designated as 13AT, was isolated from a river sediment sample of Fuyang River in Hengshui City, Hebei Province, PR China. Strain 13AT grew at 10-37 °C (optimum, 30 °C), at pH 5.0-11.0 (optimum, pH 7.0) and at 0-7 % (w/v) NaCl concentration (optimum, 0 %). Phylogenetic analysis based on the 16S rRNA gene sequence showed that strain 13AT belongs to the genus Lysobacter, and was most closely related to Lysobacter spongiicola DSM 21749T (97.8 %), Lysobacter concretionis DSM 16239T (97.5 %), Lysobacter daejeonensis GIM 1.690T (97.3 %) and Lysobacter arseniciresistens CGMCC 1.10752T (96.9 %). Meanwhile, the type species Lysobacter enzymogenes ATCC 29487T was selected as a reference strain (95.2 %). The genomic size of strain 13AT was 3.0 Mb and the DNA G+C content was 69.0 %. The average nucleotide identity values between strain 13AT and each of the reference type strains L. spongiicola DSM 21749T, L. concretionis DSM 16239T, L. daejeonensis GIM 1.690T, L. arseniciresistens CGMCC 1.10752T and L. enzymogenes ATCC 29487T were 75.9, 76.1, 77.7, 78.0 and 73.2 %, respectively. The digital DNA-DNA hybridization values between strain 13AT and each of the reference type strains were 21.7, 22.2, 21.9, 22.7 and 23.2 %, respectively. The average amino acid identity values between strain 13AT and each of the reference type strains were 72.5, 72.9, 72.3, 75.0 and 69.2 %, respectively. The major fatty acids were iso-C15 : 0, iso-C16 : 0 and summed feature 9 (iso-C17 : 1 ω9c and/or C16 : 0 10-methyl). The sole respiratory quinone was identified as ubiquinone-8. The polar lipid profile contained phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, an unidentified aminolipid, an unidentified lipid, four unidentified phospholipids and two unidentified glycolipids. Based on the phenotypic, physiological, phylogenetic and chemotaxonomic data, strain 13AT represents a novel species of the genus Lysobacter, for which the name Lysobacter selenitireducens sp. nov. is proposed. The type strain is 13AT (=JCM 34786T=GDMCC 1.2722T).

Flavobacterium selenitireducens sp. nov., isolated from rhizosphere soil of ancient mulberry.

A Gram-stain-negative, non-motile, aerobic, yellow, convex, rod-shaped mesophilic bacterial strain, designated strain D33T, was isolated from rhizosphere soil of ancient mulberry in Dezhou city, Shandong province, PR China. The strain grew at 8-37 °C (optimum, 30 °C), pH 4-9 (optimum, pH 7) and growth occurred at 0.5-5.5 % (w/v) NaCl (optimally at 1 %). The results of the phylogenetic analyses of 16S rRNA gene and whole genome sequences indicated that D33T was closely related to members of the genus Flavobacterium and had the highest 16S rRNA gene sequence similarity with 'Flavobacterium agri' KACC 19300 (95.4 %), Flavobacterium ichthyis NST-5T (94.6 %), Flavobacterium ahnfeltiae KCTC 32467T (93.6 %) and Flavobacterium longum JCM 19141T (93.6 %). The genome size of D33T was 3.8 Mb and the DNA G+C content was 48.0 mol%. The average nucleotide identity (ANI), digital DNA-DNA hybridization (dDDH) and average amino acid identity (AAI) values among D33T and reference strains were lower than the threshold values for species delineation. The only respiratory quinone of D33T was menaquinone 6 (MK-6). The predominant fatty acids (>5 %) were C15:0, C16 : 0, C18 : 0, iso-C15:0, iso-C17 : 0 3-OH, anteiso-C15 : 0 and summed feature 9 . The polar lipid profile contained phosphatidylethanolamine, two unidentified aminophospholipids, three unidentified aminolipids and two unidentified lipids. Combined data from phenotypic, phylogenetic and chemotaxonomic studies indicated that D33T is a representative of a novel species of the genus Flavobacterium, for which the name Flavobacterium selenitireducens sp. nov. is proposed. The type strain is D33T (=GDMCC 1.1946T=KACC 22131T).

A combination of the K-L and S-P approaches for treating acetabular posterior wall factures accompanied by femoral head fractures with open reduction and internal fixation.

BACKGROUND: In clinical practice, acetabular posterior wall fracture combined with femoral head fracture is rare. However, with the increasing number of engineering and traffic accidents, such fractures, have increased significantly in recent years. This paper aims to explore the clinical efficiency of the Kocher-Langenbeck (K-L) and Smith-Petersen (S-P) combined approaches for open reduction and internal fixation (ORIF) of acetabular posterior wall fractures accompanied by femoral head fractures (Pipkin type IV fractures). METHODS: A retrospective study was conducted on 8 patients who underwent open reduction and internal fixation (ORIF) of Pipkin type IV fractures through the K-L combined with S-P approach in our hospital from January 2015 to January 2020. All 8 patients were successfully operated on without serious complications, such as important blood vessel and nerve damage, with an operation time of 143.8 ± 44.38 min and intraoperative blood loss of 225 ± 70.71 ml. Perioperative data were recorded. The Harris score was used to evaluate the clinical effect. Fracture reduction quality was evaluated according to the Matta radiological standard. The grade of ectopic ossification was evaluated by the Brooker grading method, and the stage of femoral head necrosis was evaluated by Ficat-Arlet staging. RESULTS: The Harris score increased significantly from 57.38 ± 4.779 at 3 months, to 76.13 ± 3.682 at 6 months, 88.25 ± 3.495 at 12 months, and 92.13 ± 2.232 at 36 months postoperatively. After statistical analysis, compared with the previous observation time point, the data comparison differences between the groups were statistically significant. P < 0.001, P < 0.001, P < 0.05). By the time of the latest follow-up, 6 of the 8 patients had recovered to the level of pre-injury sports capacity. In contrast, the other 2 patients remained below the level of pre-injury sports capacity. In terms of imaging evaluation, the quality of fracture reduction on radiographs was graded as excellent in 6 patients and good in 2 patients according to Matta's criteria. At the last follow-up, no heterotopic ossification or femoral head necrosis was found in of all the images. In addition, the hip joint space was normal in 6 cases, mildly narrowed in 1 case, and clearly narrowed in 1 case. CONCLUSIONS: The K-L combined with S-P approach provides effective exposure for the reduction and fixation of Pipkin type IV fractures and achieves satisfactory clinical outcomes.