A cross-sectional analysis of the relationship between the non-high density to high density lipoprotein cholesterol ratio (NHHR) and kidney stone risk in American adults.

BACKGROUND: Recent interest in the Non-High Density to High Density Lipoprotein Cholesterol ratio (NHHR) has emerged due to its potential role in metabolic disorders. However, the connection between NHHR and the development of kidney stones still lacks clarity. The primary goal of this research is to explore how NHHR correlates with kidney stone incidence. METHODS: An analysis was conducted on the data collected by the National Health and Nutrition Examination Survey (NHANES) between 2007 and 2018, focusing on adults over 20 years diagnosed with kidney stones and those with available NHHR values. Employing weighted logistic regression and Restricted Cubic Spline (RCS) models, NHHR levels' correlation with kidney stone risk was examined. Extensive subgroup analyses were conducted for enhanced reliability of the findings. RESULTS: The findings indicate a heightened kidney stone risk for those at the highest NHHR levels relative to those at the lowest (reference group). A notable non-linear correlation of NHHR with kidney stone incidence has been observed, with a significant P-value (< 0.001), consistent across various subgroups. CONCLUSION: A clear link exists between high NHHR levels and increased kidney stone risk in the American adult population. This study highlights NHHR's significance as a potential indicator in kidney stone formation.

Modified Minimally Invasive Bunnell Suture Surgery with Channel-assisted Minimally Invasive Reconstruction Device for Treating Achilles Tendon Rupture.

The aim of this study was to improve the process of microincision and endoscopic surgery for the treatment of Achilles tendon (AT) rupture using the modified minimally invasive Bunnell suture (MIBS) technique.From December 2019 to December 2021, 20 patients with AT rupture who visited the First Affiliated Hospital of Harbin Medical University (Harbin, China) underwent MIBS surgery.A total of 20 patients were included, of whom 18 (90.0%) were male and 2 (10.0%) were female. The mean age of the patients was 37.75 ± 9.94 years. In terms of the site of the AT, two (10.0%) had surgery on their left AT. The mean duration of surgery was 23.00 ± 2.47 minutes, and the mean bleeding volume was 5.00 ± 1.12 mL. All 20 patients (100%) showed complete incisional healing (stage I healing) and normal functional recovery (3-6 months postoperatively). There were no cases of abnormal functional recovery or postoperative recurrence within the 3-6 month follow-up period. The Achilles tendon Total Rupture Score (ATRS) significantly improved post-surgery (83.6 ± 5.59) compared to pretreatment (0.3 ± 0.92, p < 0.0001), indicating successful patient recovery.After the modified MIBS surgical process, the operation steps were simplified, the surgical difficulty was reduced, and the surgical trauma was alleviated, resulting in good postoperative recovery and patient satisfaction with the outcome. Therefore, the MIBS surgery has high promotability.

Association between kidney stones and life's essential 8: a population-based study.

BACKGROUND: Kidney stones exhibit a robust correlation with cardiovascular disease (CVD). The objective of this research is to investigate the correlation between kidney stones and Life's Essential 8 (LE8), a newly updated assessment of cardiovascular health (CVH), among adults in the United States. METHODS: In this study, which analyzed data from the 2007-2018 National Health and Nutrition Examination Survey, we employed LE8 scores (ranging from 0 to 100) as the independent variable, classifying them into low, moderate, and high CVH categories. The research examined the relationship between LE8 scores and kidney stones by using multivariate logistic regression and restricted cubic spline models, with kidney stones as the dependent variable. RESULTS: Out of the 14,117 participants in this research, the weighted mean LE8 score was 69.70 ± 0.27. After accounting for confounding factors, there was an inverse association between higher LE8 scores and the likelihood of developing kidney stones (OR of 0.81 per 10-point increase, with a 95% confidence interval of 0.77-0.85), demonstrating a non-linear dose-response pattern. Similar patterns were observed for health behaviors, health factor scores, and kidney stones. Stratified analyses demonstrated a stable negative correlation between LE8 scores and kidney stones across different subgroups. CONCLUSION: LE8 and its subscale scores exhibited a robust and inverse correlation with the occurrence of kidney stones. Encouraging adherence to optimal CVH levels has the potential to serve as an effective strategy in preventing and minimizing the occurrence of kidney stones.

Bacterial templated carbonate mineralization: insights from concave-type crystals induced by Curvibacter lanceolatus strain HJ-1.

The elucidation of carbonate crystal growth mechanisms contributes to a deeper comprehension of microbial-induced carbonate precipitation processes. In this research, the Curvibacter lanceolatus HJ-1 strain, well-known for its proficiency in inducing carbonate mineralization, was employed to trigger the formation of concave-type carbonate minerals. The study meticulously tracked the temporal alterations in the culture solution and conducted comprehensive analyses of the precipitated minerals' mineralogy and morphology using advanced techniques such as X-ray diffraction, scanning electron microscopy, focused ion beam, and transmission electron microscopy. The findings unequivocally demonstrate that concave-type carbonate minerals are meticulously templated by bacterial biofilms and employ calcified bacteria as their fundamental structural components. The precise morphological evolution pathway can be delineated as follows: initiation with the formation of bacterial biofilms, followed by the aggregation of calcified bacterial clusters, ultimately leading to the emergence of concave-type minerals characterized by disc-shaped, sunflower-shaped, and spherical morphologies.

Metformin Reduces the Risk of Total Hip Arthroplasty in Elderly Patients with Hip Osteoarthritis and Type 2 Diabetes Mellitus.

Purpose: To assess if metformin could reduce the risk of total hip arthroplasty (THA) in elderly patients with hip osteoarthritis and type 2 diabetes (T2DM). Patients and Methods: It is a retrospective study among elderly patients (≥65 years) with hip osteoarthritis and T2DM. All included patients were divided into metformin group and non-metformin group, then propensity-score match (PSM) was performed to control potential confounding factors. The primary endpoint was the incidence of the first THA during the study period. Multivariate Cox regression analysis was employed to evaluate the association of metformin with the risk of THA. Results: A matched cohort of 716 patients were finally included, with 308 metformin users and 308 metformin non-users. During a maximum follow-up of 10 years, the incidence of THA in metformin users was significantly lower than that in non-users (4.9% vs 25.0%, P<0.01). Multivariate Cox regression analysis indicated that metformin users were significantly associated with a lower risk of THA compared with non-users (HR = 0.17, 95% CI: 0.10-0.30; P<0.01). In addition, further analyses indicated that participants with long-term metformin use (HR = 0.10, 95% CI: 0.02-0.46; P<0.01) or high metformin dosage (HR = 0.15, 95% CI: 0.04-0.57; P<0.01) had a lower risk of THA. Conclusion: Metformin use could reduce the risk of THA in patients with hip osteoarthritis and T2DM, and the effect is accumulative and dose dependent.

Biomimetic Mineralization of Ca-Mg Carbonates: Relevance to Microbial Cells and Extracellular Polymeric Substances.

Research on Ca-Mg carbonate crystallization and phase transition regulated by microbial cells and extracellular polymeric substances (EPS) is significant for carbon sequestration, remediation of polluted soil and water, and synthesis of functional biomaterials. This study focused on the mineralogical transformation from amorphism to crystal, and interaction among cells, EPS, and minerals. By tracing the law of mineral growth and morphological evolution, the influences of cells and EPS on mineral formation were investigated. The results revealed that calcification and the template of rod-shaped cells of strain HJ-1 were the basis for the formation of dumbbell-shaped particles, and directional aggregation and differential growth were the keys to the development and stability of dumbbells. Cell participation had a noticeable impact on mineral prototypes, instead of determining the polymorphism. EPS contributed to aragonite formation and stability. The acidic amino acids or proteins in EPS were likely to cause an increase in MgCO3 content in Mg-calcite. EPS promoted aggregation of particles and induced spherical formation. Exopolysaccharides and proteins were the main components of EPS that can affect carbonate mineralization. EPS could influence the morphology and polymorphism by providing nucleation sites, interacting with Mg2+, adsorbing or incorporating mineral lattices, and inducing particle aggregation.

Formation mechanism of disc-shaped calcite-a case study on Arthrobacter sp. MF-2.

Research on the biogenic-specific morphology of carbonate minerals has made progress in the fields of biomineralization and industrial engineering. In this study, mineralization experiments were performed using Arthrobacter sp. MF-2, including its biofilms. The results showed that a particular morphology of minerals (i.e., disc-shaped) was observed in the mineralization experiments with strain MF-2. The disc-shaped minerals were formed near the air/solution interface. We also observed that disc-shaped minerals formed in experiments with the biofilms of strain MF-2. Therefore, the nucleation of carbonate particles on the biofilm templates produced a novel disc-shaped morphology which was assembled from calcite nanocrystals radiating out from the periphery of the template biofilms. Further, we propose a possible formation mechanism of the disc-shaped morphology. This study may provide new perspectives on the formation mechanism of carbonate morphogenesis in the process of biomineralization.

Deep-blue thermally activated delayed fluorescence carbon dots with ultralong lifetime.

Carbon dots (CDs) with deep-blue thermally activated delayed fluorescence (TADF) of more than 2 s were developed, exhibiting the longest lifetime to date. In contrast to the established deep-blue TADF systems, this developed CD-based system (BNCDs) could be facilely and effectively synthesized, and more impressively, the emission lasted for more than 16 s (to the naked eye). XRD, TEM, FT-IR, and XPS analyses were conducted, and structural characterizations indicated that the CDs formed hydrogen bonding with B2O3. The temperature-dependent photoluminescence (PL) spectra demonstrated the existence of thermally activated delayed fluorescence in the composite. Further studies revealed that the B2O3 matrix restricted the vibration and rotation of CD chromophores and suppressed the non-radiative recombination of triplet excitons. Last but not least, potential applications in bioimaging, anti-counterfeiting, and information encryption were also explored. This work can provide new insights for developing metal-free and ultralong lifetime afterglow materials.

The effect of Bacillus cereus LV-1 on the crystallization and polymorphs of calcium carbonate.

The study of CaCO3 polymorphism is of great significance for understanding the mechanism of carbonate mineralization induced by bacteria and the genesis of carbonate rock throughout geological history. To investigate the effect of bacteria and shear force on CaCO3 precipitation and polymorphs, biomineralization experiments with Bacillus cereus strain LV-1 were conducted under the standing and shaking conditions. The results show that LV-1 induced the formation of calcite and vaterite under the standing and shaking conditions, respectively. However, the results of mineralization in the media and the CaCl2 solution under both kinetic conditions suggest the shear force does not affect the polymorphs of calcium carbonate in abiotic systems. Further, mineralization experiments with bacterial cells and extracellular polymeric substances (EPS) were performed under the standing conditions. The results reveal that bacterial cells, bound EPS (BEPS), and soluble EPS (SEPS) are favorable to the formation of spherical, imperfect rhombohedral, and perfect rhombohedral minerals, respectively. The increase in the pH value and saturation index (SI) caused by LV-1 metabolism under the shear force played key roles in controlling vaterite precipitation, whereas bacterial cells and EPS do not play roles in promoting vaterite formation. Furthermore, we suggest that vaterite formed if pH > 8.5 and SIACC > 0.8, while calcite formed if pH was between 8.0-9.0 and SIACC < 0.8. Bacterial cells and BEPS are the main factors affecting CaCO3 morphologies in the mineralization process of LV-1. This may provide a deeper insight into the regulation mechanism of the polymorphs and morphologies during bacterially induced carbonate mineralization.

ORC6 acts as a biomarker and reflects poor outcome in clear cell renal cell carcinoma.

Purpose: To explore the role of ORC6 in clear cell renal cell carcinoma (ccRCC). Methods: The Cancer Genome Atlas Kidney Clear Cell Carcinoma (TCGA-KIRC) database was used to investigate the association between ORC6 expression and clinicopathological parameters. Furthermore, the expression level of ORC6 was determined in human RCC tissues and cell lines by western blot and PCR. Receiver operating characteristics curves and Kaplan-Meier curves were performed to assess the diagnostic and prognostic value of ORC6 in RCC. Results: High expression of ORC6 predicted shorter overall survival (OS) (P<0.0001) and acted as an independent prognostic factor. ORC6 could distinguish the tumor from the normal patient (area under the curve=0.8827, P<0.0001). The expression of ORC6 was associated with the P53 signaling pathway, cell cycle, and DNA replication. Conclusion: ORC6 could serve as a useful diagnostic and prognostic biomarker and a potential therapeutic target for ccRCC.

m6 A transferase KIAA1429-stabilized LINC00958 accelerates gastric cancer aerobic glycolysis through targeting GLUT1.

Emerging evidence has demonstrated that N6 -methyladenosine (m6 A) and long noncoding RNAs (lncRNAs) are both crucial regulators in gastric cancer (GC) tumorigenesis. However, the interaction of m6 A and lncRNAs in GC progression are still unclear. Here, our team discovered that lncRNA LINC00958 expression up-regulated in GC tissue and cells. Clinically, high-expression of LINC00958 was clinically correlated to lower survival of GC patients. Functionally, in vitro assays demonstrated that LINC00958 promoted the GC cells' aerobic glycolysis. Mechanistically, methylated RNA immunoprecipitation sequencing (MeRIP-Seq) found that there were m6 A-modificated sites in LINC00958, and moreover m6 A methyltransferase KIAA1429 catalyzed the m6 A modification on LINC00958 loci. Moreover, LINC00958 interacted with GLUT1 mRNA via the m6 A-dependent manner to enhance GLUT1 mRNA transcript stability, thereby positively regulating the aerobic glycolysis of GC. In conclusion, our findings reveal the function and mechanism of KIAA1429-induced LINC00958 in GC, delineating novel understanding of m6 A-lncRNA in cancer biology.

Mechanism of carbonate mineralization induced by microbes: Taking Curvibacter lanceolatus strain HJ-1 as an example.

Microbial-induced carbonate precipitation is important in the global carbon cycle, especially in fixing atmospheric CO2. Many simulation experiments have shown that microbes can induce carbonate precipitation, although there is no established understanding of the mechanism. In this study, several mineralization experiments were performed using Curvibacter lanceolatus strain HJ-1, including its secreted extracellular polymeric substances (EPS) and carbonic anhydrase (CA). We found that strain HJ-1, EPS, and CA could promote carbonate precipitation if compared with the respective control experiments (CK). Also, both HJ-1 and EPS1 experiments contained calcite and aragonite, whereas CA experiments formed calcite only. Therefore, HJ-1 and EPS is favorable for carbonate precipitation, especially for aragonite. Besides, the formation of calcite in the EPS2 experiments indicated that EPS contains a trace amount of CA, which might promote CO2 hydration and eventually lead to carbonate precipitation. It was suggested that CA only provide CO32- for the formation of carbonate minerals. In the absence of exogenous HCO3-, the optimized calcification rate followed the order: HJ-1(49.5 %) > CA(6.6 %) > EPS2(4.1 %). In addition, MICP mechanisms was studied, an increase in pH and CO2 hydration by CA play synergetic roles in providing supersaturated alkaline conditions in the system with bacteria. Finally, bacterial cells and EPS promote the formation of calcite and aragonite by acting as nucleation sites.

Comparison of carbonate precipitation induced by Curvibacter sp. HJ-1 and Arthrobacter sp. MF-2: Further insight into the biomineralization process.

Microorganisms are generally involved in the nucleation, growth and phase transformation of carbonate minerals, and influence the development of their morphology and polymorphism. However, understanding of the process of microbially induced carbonate precipitation (MICP) remains limited. Herein, MICP experiments were carried out using Curvibacter sp. HJ-1 and Arthrobacter sp. MF-2 in M2 medium, and the processes of MICP were monitored. Bacterial cells induced the precipitation of carbonate by creating favorable physicochemical conditions and acting as nucleation templates for carbonate particles and thereby, markedly influenced the morphology and growth of the carbonate structure. The extracellular polymeric substance (EPS) secreted by the bacteria was readily absorbed by the precipitated carbonate, which modified its crystal growth orientation. The MgCO3 content of Mg-calcite, induced by MF-2, was dramatically higher than that induced by HJ-1; HJ-1 promoted the formation and stability of aragonite. Multiple formation mechanisms coexisted during the evolution process of the mineral morphologies in the presence of the bacteria. The spherulites observed mainly evolved from dumbbell-like precursors in the presence of MF-2, whereas aggregate growth was the main formation mechanism of radial spherulites in the presence of HJ-1.

Controlled Crystallization and Transformation of Carbonate Minerals with Dumbbell-like Morphologies on Bacterial Cell Templates.

Research on the biogenic-specific polymorphism and morphology of carbonate has been gaining momentum in the fields of biomineralization and industrial engineering in recent years. We report the nucleation of carbonate particles on bacterial cell templates to produce a novel dumbbell-like morphology which was assembled by needle-like crystals of magnesium calcite or aragonite radiating out from both ends of the template bacterium. Mature dumbbell-like structures had a tendency to break apart in the central template region, which was made up mostly of weak amorphous carbonate. Further crystal growth, especially at the template region, transformed the broken pieces into spherulites. Rod-like cell templates were essential for the formation of dumbbell-like morphologies, and we propose a possible formation mechanism of the dumbbell-like morphology. Our findings provide new perspectives on the morphological formation mechanism in biomineralization systems and may have a potential significance in assembling composite materials suitable for industrial applications.

Low­intensity ultrasound enhances the chemosensitivity of hepatocellular carcinoma cells to cisplatin via altering the miR­34a/c­Met axis.

Recently, the use of low­intensity ultrasound (LIUS) combined with chemotherapeutic agents is widely used in clinical practice, mainly for the treatment of cancer; however, the mechanisms as to how LIUS enhances the antitumor effects of these agents are not fully understood. The aim of the present study was to explore the synergistic antitumor effects and mechanisms of cisplatin (DDP) combined with LIUS (LIUS­DDP) in hepatocellular carcinoma (HCC). We reported that LIUS effectively enhanced Huh7 and HCCLM3 cell sensitivity to a low concentration of DDP. Reverse transcription­quantitative polymerase chain reaction analysis revealed that LIUS could increase the expression of microRNA­34a (miR­34a) in HCC cells following DDP treatment. In addition, LIUS­DDP significantly increased intracellular reactive oxygen species (ROS) levels in vitro, and the upregulation of miR­34a induced by LIUS­DDP was reversed by the ROS scavenger N­acetylcysteine, suggesting that LIUS upregulates the expression of miR­34a via production of ROS. In addition, knockdown of miR­34a in HCC cells significantly suppressed the synergistic effects of LIUS­DDP treatment. Conversely, overexpression of miR­34a enhanced these synergistic effects. The results of a dual­luciferase assay indicated that c­Met, a well­known oncogene, was a target of miR­34a. We also determined that LIUS­DDP treatment inhibited the expression of c­Met, possibly due to increased ROS production, which upregulated miR­34a expression. Furthermore, overexpression of c­Met reversed the synergistic effects of LIUS­DDP treatment. Our findings suggest that LIUS could enhance the chemosensitivity of HCC cells to DDP by altering the miR­34a/c­Met axis. Therefore, DDP combined with LIUS may be a potential therapeutic application for the clinical treatment of patients with HCC.

Spatial-temporal variations and mineral dust fractions in particulate matter mass concentrations in an urban area of northwestern China.

PM10 and PM2.5 concentration data were collected from five air-quality monitoring sites in Lanzhou from October 2014 to October 2015, revealing the spatial-temporal behavior of local particulate matter (PM). The Hybrid Single Particle Lagrangian Integrated Trajectory Model (HYSPLIT) and the PM2.5-to-PM10 ratio model were used to investigate the primary transport path, potential source areas and contributions of the East Asian sandstorm to PM in Lanzhou. The analysis in three functional areas of the city indicated that the monthly variation in PM2.5 displayed a unimodal U pattern (the highest value was during the heating period), whereas that of PM10 displayed a bimodal pattern (the primary peak appeared in the spring, and the secondary peak appeared in the winter). These two patterns originated from different PM sources. The PM2.5 was primarily affected by human activities, and the PM10 was influenced by both natural and anthropogenic activities, but the relative contributions of these activities were associated with spatial-temporal variations. The daily PM10 and PM2.5 concentration variations displayed a bimodal pattern in the three functional areas: the peak values appeared at 11:00-13:00 and 22:00-1:00, respectively, and the lowest values appeared at 4:00-6:00 and 16:00-18:00, respectively. On the monthly, seasonal and daily scales, the PM concentrations exhibited similar patterns in the industrial, urban and rural areas, indicating that they were partly controlled by the regional natural environment. Meanwhile, due to anthropogenic factors, considerable PM amounts were discharged into the external environment, leading to maximum and minimum concentrations of PM appearing in the industrial and rural areas, respectively. The HYSPLIT model showed that dust storms from the northwest desert and Gobi regions affected Lanzhou three times in March 2015 and contributed 68% and 40% of the total mass of PM10 and PM2.5, respectively.

Nucleation and Growth of Mg-Calcite Spherulites Induced by the Bacterium Curvibacter lanceolatus Strain HJ-1.

Calcite spherulites have been observed in many laboratory experiments with different bacteria, and spherulitic growth has received much interest in mineralogy research. However, the nucleation and growth mechanism, as well as geological significance of calcite spherulites in solution with bacteria is still unclear. Herein, spherulites composed of an amorphous core, a Mg-calcite body and an organic film were precipitated by the Curvibacter lanceolatus HJ-1 bacterial strain in a solution with a molar Mg/Ca ratio of 3. Based on the results, we provide a possible mechanism for the biomineralization of Mg-calcite spherulites. First, amorphous calcium carbonate particles are deposited and aggregated into a stable sphere-like core in combination with organic molecules. The core then acts as the nucleus of spherulitic radial growth. Finally, the organic film grows on the surface of Mg-calcite spherulites as a result of bacterial metabolism and calcification. These findings provide insight into the growth mode and crystallization of biogenic spherulites during biomineralization, and are of significance in the application of novel biological materials.

Effects of hUCB-MSCs on recovery of neurological function and TERT expression in brain tissue of rats with cerebral ischemia-reperfusion injury.

The aim of this study was to investigate and analyze the effects of human umbilical cord blood mesenchymal stem cells (hUCB-MSCs) on the recovery of neurological function and telomerase reverse transcriptase (TERT) expression in brain tissue of rats with cerebral ischemia-reperfusion injury. A total of 100 healthy adult Wistar rats were randomly divided into two groups: The control group and the observation group according to the random number table method. After the model of cerebral ischemia-reperfusion injury was established, the rats in the observation group were treated with hUCB-MSCs (10 ml/kg), while the rats in the control group were treated with saline every day. The neurological deficit score and foot fault test were evaluated at 1, 7 and 14 days after treatment, and the rats were sacrificed at 14 days to detect the expression of TERT in brain tissue. There was no significant difference in the scores of mNSS between the two groups before the model establishment (P>0.05), but there was significant differences in two groups after the operation (P<0.05). At 1 day after the operation, the mNSS score of the two groups peaked, which was decreased in the groups with the progress of treatment. The degree of decline in the observation group was significantly greater than that in the control group (P<0.05). Similarly, there was no significant difference in the number of errors between the two groups before the model establishment (P>0.05), but there was significant difference in two groups after the operation (P<0.05). At 1 day after the operation, the number of errors also peaked, which was reduced in the groups with the progress of treatment. The degree of reduction in the observation group was significantly greater than that in the control group (P<0.05). The results of H&E staining showed it had positive reaction as nucleus or cytoplasm stained brown or yellowish brown in the observation group, while it showed neuronal shrinkage, cytoplasm and nucleus yellow dye deepening in the control group as the significant positive reaction. The gray level of the TERT protein in the brain tissue of the control group was 0.458±0.052 LOD, which was significantly lower than that in the observation group with 0.983±0.056 LOD (P<0.05). In conclusion, hUCB-MSCs can effectively improve the neurological function and the expression of TERT in brain tissue of rats with cerebral ischemia-reperfusion injury, which may be helpful to reduce the ischemia-reperfusion injury of brain tissue.

Vaterite induced by Lysinibacillus sp. GW-2 strain and its stability.

Studies on the formation and stability of vaterite by bacteria in experimental systems are of great importance for understanding the mechanism by which microbes contribute to carbonate mineralization. In this study, mineralization experiments using Lysinibacillus sp. strain GW-2 were carried out for 72h under shaking conditions and aging experiments using biotic and chemically synthesized vaterite were performed for 60days in distilled water and air. Our results indicate that Lysinibacillus sp. strain GW-2 can induce the formation of vaterite with spherical morphology from an amorphous calcium carbonate precursor. Biogenic vaterite was more stable than chemically synthesized vaterite in distilled water, perhaps due to organic matter secreted by bacteria that enwrapped the vaterite and prevented it from transforming into more stable phases. Infrared spectrophotometry of biogenic and chemically synthesized vaterite confirmed the presence of organic matter in biogenic vaterite.

[Curvibacter sp. strain HJ-1 induced the formation of aragonite under the condition of low Mg/Ca ratio].

Objective: To study the effects of bacteria on the species and morphology of carbonate minerals. Methods: We conducted a series of cultural experiments in the medium with initial Mg/Ca ratio of 2 but without carbonate ion using Curvibacter sp. strain HJ-1 for 50 days. During the cultivation, bacterial density, precipitate quantities, calcium and magnesium concentration were determined. The morphologies of precipitated carbonates were observed using scanning electron microscopy, and mineral species of carbonate were determined by X-ray diffraction. Results: Strain HJ-1 could induce the precipitation of carbonate minerals, the quality of carbonate gradually increased with the incubation time. XRD patterns showed that the mineral precipitates consisted of high-Mg calcite and aragonite. The percentage of aragonite in the precipitates was up to 86%. The morphology of carbonate minerals was multiform, including rod-shaped, dumbbell-shaped, spherical, tabular, as well as irregular and flake. Conclusion: The formation of aragonite under the condition of low Mg/Ca ratio has a close correlation with extracellular polysaccharide secreted by Curvibacter sp. strain HJ-1.