Acidification induce chemical and microbial variation in tea plantation soils and bacterial degradation of the key acidifying phenolic acids.

Camellia sinensis is an important economic plant grown in southern subtropical hilly areas, especially in China, mainly for the production of tea. Soil acidification is a significant cause of the reduction of yield and quality and continuous cropping obstacles in tea plants. Therefore, chemical and microbial properties of tea growing soils were investigated and phenolic acid-degrading bacteria were isolated from a tea plantation. Chemical and ICP-AES investigations showed that the soils tested were acidic, with pH values of 4.05-5.08, and the pH negatively correlated with K (p < 0.01), Al (p < 0.05), Fe and P. Aluminum was the highest (47-584 mg/kg) nonessential element. Based on high-throughput sequencing, a total of 34 phyla and 583 genera were identified in tea plantation soils. Proteobacteria and Acidobacteria were the main dominant phyla and the highest abundance of Acidobacteria was found in three soils, with nearly 22% for the genus Gp2. Based on the functional abundance values, general function predicts the highest abundance, while the abundance of amino acids and carbon transport and metabolism were higher in soils with pH less than 5. According to Biolog Eco Plate™ assay, the soil microorganisms utilized amino acids well, followed by polymers and phenolic acids. Three strains with good phenolic acid degradation rates were obtained, and they were identified as Bacillus thuringiensis B1, Bacillus amyloliquefaciens B2 and Bacillus subtilis B3, respectively. The three strains significantly relieved the inhibition of peanut germination and growth by ferulic acid, p-coumaric acid, p-hydroxybenzoic acid, cinnamic acid, and mixed acids. Combination of the three isolates showed reduced relief of the four phenolic acids due to the antagonist of B2 against B1 and B3. The three phenolic acid degradation strains isolated from acidic soils display potential in improving the acidification and imbalance in soils of C. sinensis.

Screening of cadmium resistant bacteria and their growth promotion of Sorghum bicolor (L.) Moench under cadmium stress.

Heavy metal pollution of agricultural soils, especially from cadmium (Cd) contaminationcaused serious problems in both food security and economy. Sorghum bicolor (L.) showed a great potential in phytoremediation of Cd contamination due to its fast growth, high yield and easy harvesting. However, the growth of S. bicolor plants tends to be inhibited under Cd exposure, which limited its application for Cd remediation. Plant growth-promoting rhizobacteria may enhance the Cd resistance of S. bicolor and thus improve its Cd removal efficiency. In this study, three Cd-resistant bacteria were screened based on Cd and acid tolerance and identified as Bacillus velezensis QZG6, Enterobacter cloacae QZS3 and Bacillus cereus QZS8, by 16S rRNA sequencing. Inoculation of hydroponic plants with strains QZG6, QZS3 or QZS8 significantly promoted the biomass of sorghum plants by 31.52%, 50.20% and 26.93%, respectively, compared with those of uninoculated plants under Cd exposure. The activity of SOD, POD and MDA content in Cd-stressed S. bicolor plants were reduced of 65.74%, 31.52%, and 80.91%, respectively, when inoculated with the strains QZS3. For pot experiment, strains QZG6, QZS3 and QZS8 significantly promoted the biomass of sorghum plants by 47.30%, 19.27% and 58.47%, compared with those of uninoculated plants under Cd exposure. The activity of SOD, POD and MDA content in Cd-stressed S. bicolor plants were reduced of 67.20%, 22.40%, and 40.65%, respectively, when inoculated with the strains QZS3. All these three strains significantly increased the Cd removal efficiency of the plants by 42.16% (QZG6), 18.76% (QZS3) and 21.06% (QZS8). To investigate the bacterial characteristics associated with growth promotion of S. bicolor plants, the ability on nitrogen fixation, phosphorus solubilization, siderophores production, and phytohormones production were determined. All the strains were able to fix nitrogen. Phosphorus release was observed for strains QZG6 (inorganic or organic phosphorus) and QZS3 (inorganic phosphorus). Both QZG6 and QZS8 were able to produce siderophores, while only QZG6 was positive for ACC deaminase. All the strains produced IAA, SA and GA. These results indicated that the three strains promoted the plant growth under Cd stress, probably through Cd detoxification by siderophores, as well as through growth regulation by N/P nutrient supply and phytohormone. The present study showed a great potential of the three Cd-resistant strains combined with S. bicolor plants in the remediation of Cd-polluted soils, which may provide a new insight into combining the advantages of microbes and plants to improve the remediation of Cd-contaminated soils.

Complete genome of Sphingomonas paucimobilis ZJSH1, an endophytic bacterium from Dendrobium officinale with stress resistance and growth promotion potential.

Sphingomonas paucimobilis ZJSH1 is an endophytic bacterium isolated from the roots of Dendrobium officinale with the ability to promote plant growth. It was found that the genome of strain ZJSH1 had gene fragment rearrangement compared with the genomes of the other four strains of S. paucimobilis, and the genome was integrated with phage genes. Functional analysis showed that the strain contained colonization-related genes, chemotaxis and invasion. A variety of genes encoding active materials, such as hormones (IAA, SA, ABA and zeaxanthin), phosphate cycle, antioxidant enzymes, and polysaccharides were identified which provide the strain with growth promotion and stress-resistant characteristics. Experiments proved that S. paucimobilis ZJSH1 grew well in media containing 80 g/L sodium chloride, 240 g/L polyethylene glycol and 800 µmol/L Cd2+, indicating its potential for resistance to stresses of salt, drought and cadmium, respectively. S. paucimobilis ZJSH1 is the only endophytic bacterium of this species that has been reported to promote plant growth. The analysis of its genome is conducive to understanding its growth-promoting mechanism and laying a foundation for the development and utilization of this species in the field of agriculture.

Biomechanical Evaluation of an Adaptive-Motion Pedicle Screw Fixation System: Experimental and Numerical Analysis.

Rigid fixation is mostly used in thoracolumbar spine surgery, which restricts the thoracolumbar spine segments moving and is not conducive to postoperative rehabilitation. We developed an adaptive-motion pedicle screw and established a finite element model of the T12-L3 segments of the thoracolumbar spine in osteoporosis patients based on the CT image data. A variety of internal fixation finite element models were established for mechanical simulation analysis and comparison. The simulation results showed that compared with the conventional internal fixation system, the mobility of the new adaptive-motion internal fixation system was improved by about 13.8% and 7.7% under the classic conditions such as lateral bending and flexion. in vitro experiments were conducted simultaneously with fresh porcine thoracolumbar spine vertebrae, and the axial rotation condition was taken as an example to analyze the mobility. The in vitro results showed that the mobility of the adaptive-motion internal fixation system had better mobility characteristics under axial rotation conditions, which was consistent with the finite element analysis. The adaptive-motion pedicle screws can preserve a certain degree of vertebral mobility, and avoid excessive vertebral restriction. It also increases the stress value of the intervertebral disk, which is closer to the normal mechanical transmission of the human body, avoiding stress masking and slowing down the degeneration of the intervertebral disk. The adaptive-motion pedicle screws can reduce the peak stress of the implant and avoid surgical failure due to implant fracture.

Paracandidimonas lactea sp. nov., a urea-utilizing bacterium isolated from landfill.

A urea-utilizing bacterium, designated Q2-2 T, was isolated from landfill. Cells of strain Q2-2 T were Gram stain-negative, aerobic, short-rod bacteria. Strain Q2-2 T was observed to grow at a temperature range of 15-37℃ (optimum 30 â„ƒ), a pH range of 5.5-9.5 (optimum pH 8.0) and 0-4% (w/v) NaCl (optimum 1%). The major respiratory quinone was Q-8, and the major polar lipids were diphosphatidyl glycerol, phosphatidylethanolamine, phosphatidylmethylethanolamine, and phosphatidyl glycerol. Based on the 16S rRNA gene sequence, strain Q2-2 T had the highest similarity with Paracandidimonas caeni 24 T (98.0%), followed by Pusillimonas soli MJ07T (97.5%), Parapusillimonas granuli Ch07T (97.2%), Pusillimonas ginsengisoli DCY25T (97.1%) and Paracandidimonas soli IMT-305 T (96.4%). The ANI values between strain Q2-2 T and the above related type strains were 71.02%, 73.52%, 74.32%, 74.59% and 72.29%, respectively. The DNA G + C content of strain Q2-2 T was 61.1%. Therefore, strain Q2-2 T represents a novel species of the genus Paracandidimonas, for which the name Paracandidimonas lactea sp. nov. (type strain Q2-2 T = CGMCC 1.19179 T = JCM 34906 T) is proposed.

Directional bioconversion and optimization of stevioside into rubusoside by Lelliottia sp. LST-1.

AIMS: The present study aimed to specifically transform stevioside (ST) into rubusoside (RS) through bioconversion with high efficiency, seeking to endow steviol glycosides (SGs) with subtle flavours for commercial acceptability. METHODS AND RESULTS: An endophytic bacterium named Lelliottia LST-1 was screened and confirmed to specifically convert ST into RS, reaching a conversion rate of 75.4% after response surface optimization. Phylogenetic analysis combined with complete genome sequencing demonstrated that LST-1 was also presumed to be a new species. To further explore the principle and process of biological transformation, the potential beta-glucosidases GH3-1, GH3-2, GH3-3 and GH3-4 were expressed, purified and reacted with SGs. High-performance liquid chromatography revealed that all enzymes hydrolysed ST and generated RS, but substrate specificity analysis indicated that GH3-2 had the highest substrate specificity towards STs and the highest enzyme activity. CONCLUSION: The potential ß-glucosidase GH3-2 in Lelliottia sp. LST-1 was found to specifically and efficiently convert ST to RS. SIGNIFICANCE AND IMPACT OF STUDY: The efficient biotransformation of ST into RS will be beneficial to its large-scale production and extensive application in the food and pharmaceutical industries.

Analysis of saponins detoxification genes in Ilyonectria mors-panacis G3B inducing root rot of Panax notoginseng by RNA-Seq.

Saponins are kinds of antifungal compounds produced by Panax notoginseng to resist invasion by pathogens. Ilyonectria mors-panacis G3B was the dominant pathogen inducing root rot of P. notoginseng, and the abilities to detoxify saponins were the key to infect P. notoginseng successfully. To research the molecular mechanisms of detoxifying saponins in I. mors-panacis G3B, we used high-throughput RNA-Seq to identify 557 and 1519 differential expression genes (DEGs) in I. mors-panacis G3B with saponins treatments for 4H (Hours) and 12H (Hours) compared with no saponins treatments, respectively. Among these DEGs, we found 93 genes which were simultaneously highly expressed in I. mors-panacis G3B with saponins treatments for 4H and 12H, they mainly belong to genes encoding transporters, glycoside hydrolases, oxidation-reduction enzymes, transcription factors and so on. In addition, there were 21 putative PHI (Pathogen-Host Interaction) genes out of those 93 up-regulated genes. In this report, we analyzed virulence-associated genes in I. mors-panacis G3B which may be related to detoxifying saponins to infect P. notoginseng successfully. They provided an excellent starting point for in-depth study on pathogenicity of I. mors-panacis G3B and developed appropriate root rot disease management strategies in the future.

Foetidibacter luteolus gen. nov., sp. nov., isolated from the rhizosphere of Salvia miltiorrhiza.

A polyphosphate-producing bacterium, YG09T, was isolated from the rhizosphere of Salvia miltiorrhiza. Its colonies were 2.0-3.0 mm in diameter, smooth, circular, convex and yellow after growth on R2A at 28 °C for 72 h, with aerobic, Gram-stain-negative, non-motile and rod-shaped bacteria. The strain was found to grow at 10-40 °C (optimum 37 °C), pH 5.5-8.0 (optimum 6.0), with 0-0.6% (w/v) NaCl (optimum 0). Chemotaxonomic analysis showed menaquinone-7 as the only quinone present; C15: 1 iso G, C15: 1 iso, C16: 0, C16: 0 3OH, C17: 0 iso 3OH, summed feature 3 (C16:1 ω7c and/or C16:1 ω6c) as the major fatty acids (> 5%), and phosphatidylethanolamine, three unidentified phospholipids, four unidentified polar lipids, three unidentified aminolipids, and one unidentified amino phospholipid as the polar lipids. The DNA G + C content was 44.6 mol%. The 16S rRNA gene sequences of the isolate showed highest similarities to Panacibacter ginsenosidivorans Gsoil 1550T (93.6%), Filimonas endophytica SR2-06T (93.4%), Parasegetibacter terrae SGM2-10T (92.8%), and Arvibacter flaviflagrans C-1-16T (92.7%), within the family Chitinophagaceae of the phylum Bacteroidetes. The ANI values between strain YG09T and Panacibacter ginsenosidivoran Gsoil 1550T, Filimonas endophytica SR2-06T and Filimonas lacunae YT21T were 69.4, 68.3 and 68.7%, respectively. Based on phenotypic, genotypic and phylogenetic analyses, strain YG09T represents a novel genus in the family Chitinophagaceae, for which the name Foetidibacter luteolus gen. sp. nov. is proposed. The type strain is Foetidibacter luteolus YG09T (= MCCC 1K04042T = KCTC 72595T).

MiR-381-3p/RAB2A axis activates cell proliferation and inhibits cell apoptosis in bladder cancer.

Acting as a really common cancer in the world, bladder cancer has taken many people's life away. MiRNAs and mRNA have been reported can regulate the expression of cancers. In this study, the role of RAB2A and miR-381-3p was fully studied in bladder cancer. qRT-PCR assay probe the expression of RAB2A and miR-381-3p in bladder cancer cells. Meanwhile, colony formation assay, EdU assay, flow cytometry analysis, JC-1 assay and western blot assay were implemented to detect the progression of bladder cancer cells. Silenced RAB2A could reduce the cell proliferation of bladder cancer, and activate the apoptosis. Meanwhile, miR-381-3p could bind to RAB2A in bladder cancer cells and overexpressed miR-381-3p could inhibit the progression of bladder cancer cells. MiR-381-3p/RAB2A axis activates cell proliferation and inhibits cell apoptosis in bladder cancer.

Genome Sequence Resource for Ilyonectria mors-panacis, Causing Rusty Root Rot of Panax notoginseng.

Ilyonectria mors-panacis is the cause of a serious disease hampering the production of Panax notoginseng, an important Chinese medicinal herb, widely used for its anti-inflammatory, antifatigue, hepato-protective, and coronary heart disease prevention effects. Here, we report the first Illumina-Pacbio hybrid sequenced draft genome assembly of I. mors-panacis strain G3B and its annotation. The availability of this genome sequence not only represents an important tool toward understanding the genetics behind the infection mechanism of I. mors-panacis strain G3B but also will help illuminate the complexities of the taxonomy of this species.

Design and synthesis of various quinizarin derivatives as potential anticancer agents in acute T lymphoblastic leukemia.

A series of quinizarin derivatives containing quaternary ammonium salts and/or thiourea groups were synthesized and their anticancer activities against leukemia cell lines have been tested. Results showed that most of quinizarin derivatives could inhibit the proliferation of leukemia cells. Among these derivatives, compound 3 showed good inhibition activity against various leukemia cells with IC50 values ranging from 0.90 ±â€¯2.55 µM to 10.90 ±â€¯3.66 µM. At the same time, compound 3 also inhibited the growth of human embryonic kidney-293 cell (HEK-293). Molt-4 and Jurkat cells, acute T lymphoblastic leukemia (T-ALL) cell lines, were selected to reveal potential anticancer mechanism of compound 3. Compound 3 inhibited the proliferation of Molt-4 and Jurkat cells in a dose- and time-dependent manner and led to a marked G0/G1 phase arrest. Analysis of Annexin V-APC and intracellular reactive oxygen species (ROS) level by flow cytometry showed that compound 3 induced significant apoptosis in Molt-4 and Jurkat cells. Western blotting assay showed that compound 3 activated the caspase-dependent apoptosis pathway and induced the degradation of Bcl-2 and c-myc protein.

[The design of the software system for the interpretation and guidance of drug locus related to drug treatment].

Based on the pharmacogenomics theory, this study developed a software system for interpretation of drug gene loci and guidance on clinical safe medication with the purpose of providing clinical guidance on the safety and effectiveness of drug use through accurate and efficient detection and interpretation of drug gene loci. The system infrastructure was built on a service-oriented architecture (SOA) design and Docker container virtualization approach to achieve a rapid and automatic interpretation of genetic results and best available drugs. The front end was established on HTML5 and JavaScript to realize visualization of analysis results and user interaction. The system was tested and validated to show robust performance which is reliable in clinical use. It will show high impact on the development of pharmacogenomics and clinical practice of patients with personalized medicine.

Unveiling of Dominant Fungal Pathogens Associated With Rusty Root Rot of Panax notoginseng Based on Multiple Methods.

Root rot is an important disease hampering the sustainable cultivation of Panax notoginseng. Culture-dependent and independent techniques were used to elucidate the dominant fungal pathogen of rusty root rot of P. notoginseng. Based on Illumina sequencing profiles for fungi using ITS primers, five phyla-namely Ascomycota, Basidiomycota, Glomeromycota, Zygomycota, and Chytridiomycota-were identified, and the analyses showed that the Ascomycota was the dominant phylum (∼50 to 97%), especially in the symptomatic samples. Out of 226 total genera identified, seven genera had over 1% average abundance, including Ilyonectria, Fusarium, Tetracladium, Cladosporium, Rhizophagus, Alternaria, and Perisporiopsis. However, only Ilyonectria was the predominant genera in the symptomatic samples (∼76 to 80%), while the others, including Fusarium, had higher abundances in asymptomatic samples. Based on in vitro and in vivo pathogenicity, the isolate G3B was demonstrated to be the pathogen causing rusty root rot of P. notoginseng, and it was identified as Ilyonectria mors-panacis. Based on primers F2-R2 targeting the His3 gene of Ilyonectria, real-time quantitative PCR (qPCR) was performed as an additional proof confirming that I. mors-panacis was the dominant pathogen in the symptomatic samples during the years of the study (2014-2015).

[Implementation of control system and software design for limbs rehabilitation training based on PCI-1240].

This article presents the design of a motion control system for seated lower-limb rehabilitation training. The system is composed of lower limb exoskeleton, motor drive circuit, program of motion control, and so forth. The power of lower limbs joints is provided by six motors. The PCI-1240 motion control card is used as the core. This study achieved repetitive rotation training and gait trajectory training of lower limbs joints, of which the velocity, angle and time can be accurately controlled and adjusted. The experimental results showed that the motion control system can meet the requirement of repetitive rehabilitation training for patients with lower limb dysfunction. This article provides a new method to the research of motion control system in rehabilitation training, which can promote industrial automation technique to be used for health care, and conducive to the further study of the rehabilitation robot.

[Analysis of the Muscle Fatigue Based on Band Spectrum Entropy of Multi-channel Surface Electromyography].

Exercise-induced muscle fatigue is a phenomenon that the maximum voluntary contraction force or power output of muscle is temporarily reduced due to muscular movement.If the fatigue is not treated properly,it will bring about a severe injury to the human body.With multi-channel collection of lower limb surface electromyography signals,this article analyzes the muscle fatigue by adoption of band spectrum entropy method which combined electromyographic signal spectral analysis and nonlinear dynamics.The experimental result indicated that with the increase of muscle fatigue,muscle signal spectrum began to move to low frequency,the energy concentrated,the system complexity came down,and the band spectrum entropy which reflected the complexity was also reduced.By monitoring the entropy,we can measure the degree of muscle fatigue,and provide an indicator to judge fatigue degree for the sports training and clinical rehabilitation training.

A Novel Periplasmic Protein, VrpA, Contributes to Efficient Protein Secretion by the Type III Secretion System in Xanthomonas spp.

Efficient secretion of type III effector proteins from the bacterial cytoplasm to host cell cytosol via a type III secretion system (T3SS) is crucial for virulence of plant-pathogenic bacterium. Our previous study revealed a conserved hypothetical protein, virulence-related periplasm protein A (VrpA), which was identified as a critical virulence factor for Xanthomonas citri subsp. citri. In this study, we demonstrate that mutation of vrpA compromises X. citri subsp. citri virulence and hypersensitive response induction. This deficiency is also observed in the X. campestris pv. campestris strain, suggesting a functional conservation of VrpA in Xanthomonas spp. Our study indicates that VrpA is required for efficient protein secretion via T3SS, which is supported by multiple lines of evidence. A CyaA reporter assay shows that VrpA is involved in type III effector secretion; quantitative reverse-transcription polymerase chain reaction analysis suggests that the vrpA mutant fails to activate citrus-canker-susceptible gene CsLOB1, which is transcriptionally activated by transcription activator-like effector PthA4; in vitro secretion study reveals that VrpA plays an important role in secretion of T3SS pilus, translocon, and effector proteins. Our data also indicate that VrpA in X. citri subsp. citri localizes to bacterial periplasmic space and the periplasmic localization is required for full function of VrpA and X. citri subsp. citri virulence. Protein-protein interaction studies show that VrpA physically interacts with periplasmic T3SS components HrcJ and HrcC. However, the mutation of VrpA does not affect T3SS gene expression. Additionally, VrpA is involved in X. citri subsp. citri tolerance of oxidative stress. Our data contribute to the mechanical understanding of an important periplasmic protein VrpA in Xanthomonas spp.

[Control System Design and Test of Digital Comprehensive Training Treadmill for Rats].

This article presents the design of a treadmill of comprehensive training experiment for rats. The treadmill is composed of six tracks and two of them were designed as conventional plane, two were designed to swing right and left, and two were designed to swing back and forth. The power was provided by six motors. The MSP430F149 is used as core to adjust the swing rate and the grade of electric shock. The IAR for MSP430 is used to design the software. The speed of the six tracks could be adjusted between 0 and 30 m/min. The swing tracks of back and forth can be swung for 3-25 times per minute and the swing tracks of right and left for 3-32 times. The electric shock can be divided into three levels, i. e. strong, middle, and weak level for each track. The digital comprehensive training treadmill can meet different training needs, and provide experimental data for mechanism research of some related diseases.

[Dynamic modeling and simulating of squatting-standing action of human body].

It is very difficult for stroke patients to complete the action of squatting-standing because their equilibrium function ability has been seriously declined. It was necessary, therefore, to do a deep research on the action of human squatting-standing and to set up an accurate model and simulation. In our modeling research, the movements of upper limbs and head was neglected, and a seven-segment model was developed to establish the coordinate system of human squatting-standing action. It calculated the knee joint moment and hip joint moment during squatting and standing by utilizing Lagrange method, and then simulated this mathematical model by utilizing Matlab. Geometric model of human squatting-standing was developed and simulated in ADAMS which proved that the established Lagrange model was reasonable. It would also provide significant theoretical references for further study and development of squatting-standing rehabilitation training equipment.

Advances in hyaluronic acid production: Biosynthesis and genetic engineering strategies based on Streptococcus - A review.

Hyaluronic acid (HA), which is a highly versatile glycosaminoglycan, is widely applied across the fields of food, cosmetics, and pharmaceuticals. It is primary produced through Streptococcus fermentation, but the product presents inherent challenges concerning consistency and potential pathogenicity. However, recent strides in molecular biology have paved the way for genetic engineering, which facilitates the creation of high-yield, nonpathogenic strains adept at synthesizing HA with specific molecular weights. This comprehensive review extensively explores the molecular biology underpinning pivotal HA synthase genes, which elucidates the intricate mechanisms governing HA synthesis. Moreover, it delineates various strategies employed in engineering HA-producing strains.

Design and application of specific 16S rDNA-targeted primers for assessing endophytic diversity in Dendrobium officinale using nested PCR-DGGE.

Novel specific 16S rDNA-targeted primers were successfully designed and applied to the characterization of endophytic diversity in Dendrobium officinale. Using the popular universal bacterial primers 27f/1492r, the fragments of chloroplast and mitochondrion 16S/18S rDNA were amplified from D. officinale. They shared high nucleotide identity with the chloroplast 16S rDNAs (99-100 %) and with the mitochondrion 18S rDNAs (93-100 %) from various plants, respectively, and both shared 73-86 % identities with the bacterial 16S rDNA sequences in GenBank. The current bacterial universal primers, including 27f/1492r, match well with the chloroplast and mitochondrion 16S/18S rDNAs, which accordingly renders these primers not useful for endophytic diversity analysis. Novel 16S rDNA-targeted primers fM1 (5'-CCGCGTGNRBGAHGAAGGYYYT-3') and rC5 (5'-TAATCCTGTTTGCTCC CCAC-3') were designed, which show good specificity compared to the 16S/18S rDNAs of D. officinale, and perfect universality within bacteria except for Cyanobacteria. The primers fM1/rC5, together with 515f-GC/rC5, which overlaps the whole V4 region of 16S rDNA, were subjected to nested polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE) to analyze the diversity of endophytic bacteria in D. officinale from three different sources in China. The results showed diversities in roots and stems of the plants from all three locations. Altogether, 29 bands were identified as bacteria, with the dominant group being Proteobacteria and the dominant genus being Burkholderia, some of which commonly has the function of nitrogen fixation and thus may play potentially important roles in D. officinale. Therefore, the nested PCR-DGGE method based on the novel primers provides a good alternative for investigating the communities and roles of endophytes in D. officinale.