Aims: It has been hypothesized that root exudates can be a nutritional factor influencing the bacterial community structure as well as the occurrence of prototrophs and auxotrophs in rhizospheres. The present study was performed to examine the community structures of total bacterial DNA, cultivable bacteria and prototrophs in 3 soil samples with different levels of abundance of root exudates. Methodology and results: Denaturing gradient gel electrophoresis (DGGE) was performed to examine the community structures of total bacterial DNA, cultivable bacteria and prototrophs in 3 soil samples including bulk soil, rhizosphere of a single plant species and rhizosphere of multiple plant species. For clustering analysis, a dendrogram generated from the DGGE patterns revealed the different bacterial community structures in these soil samples. Both rhizospheres claded together, separating from bulk soil. The DGGE patterns of cultivable bacteria showed particular fingerprints corresponding to kinds of media and soil samples. Nutrient agar (NA) medium, isolation medium for prototroph (IMP) and IMP supplemented with soil extracts were used for bacterial cultivations. Prototrophs were isolated and examined by random amplified polymorphic DNA (RAPD) and 16S rRNA gene sequence analysis. The genetic diversity of prototrophs in 3 soil samples was similar (approximately 5% to 10% similarities) and most of them (13 of 28 strains) were members of Pseudomonas with 97% to 100% identities. Conclusion, significance, and impact of study: The present study provides a strong evidence of the influence of root exudates and plant species on bacterial community structures.
Denaturing Gradient Gel Electrophoresis

OBJECTIVETo research the diversity of endophytic fungal communities among Ligusticum chuanxiong growing at 5 areas in Sichuan province, and illuminate the developing mechanism of geoherbs from the microecological perspective.

METHODThe PCR-DGGE and DNA sequencing techniques were used to analyze the endophytic fungi community of L. chuanxiong.

RESULTThe community of endophytic fungi present difference among different growing areas. Though minor difference were found among individuals at the same area, similarity among individuals from the same growing areas were higher significantly than those from different growing areas. Compared with the other 4 growing areas, L. chuanxiong from Shiyang town, Dujiangyan city had more abundant endophytic fungi and low similarity to others, and which probably had special types of fungi.

CONCLUSIONThe abundant and stable endophytic fungal community is an important factor for the development of geoherb L. chuanxiong at Shiyang town, Dujiangyan city.

Denaturing Gradient Gel Electrophoresis ; methods ; Ligusticum ; genetics ; growth & development ; Polymerase Chain Reaction ; methods ; Sequence Analysis, DNA

The aim of this study was to comprehensively investigate the correlations between foliar fungal endophyte communities and effective components accumulations in Salvia miltiorrhiza. Foliar samples of S. miltiorrhiza were collected in 5 different areas. Their fungal endophyte communities and effective component contents were determined by denaturing gradient gel electrophoresis (DGGE) and high performance liquid chromatography (HPLC), respectively. The results showed that, for characteristics of foliar fungal endophyte communities and effective component contents, there were both similarities and differences among the five samples. Correlation analysis of DGGEs' band and 24 effective components revealed a significant correlations (P < 0.01). For examples, 4 bands (15, 18, 23 and 26) were all significantly correlated with the accumulations of caffeic acid, salvianolic acid B, salvianolic acid C and dihydrotanshinone I.
Chromatography, High Pressure Liquid ; Cluster Analysis ; Denaturing Gradient Gel Electrophoresis ; Endophytes ; chemistry ; Fungi ; chemistry ; Salvia miltiorrhiza ; chemistry ; microbiology

OBJECTIVETo investigate the composition of bacteria in the stools of infants and the colonization of intestinal microbiota during infancy.

METHODSFresh stools were collected from 15 healthy infants at 0, 2, 4, 7, 10, 14, and 28 days and 3, 6, and 12 months after birth. Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) was used to analyze the composition of intestinal microbiota, perform sequencing of dominant bacteria, and to analyze the changes in the composition of intestinal microbiota during infancy.

RESULTSDGGE fingerprint showed that the composition of intestinal microbiota during infancy changed significantly over time after birth. The cloning and sequencing results indicated that Proteobacteria colonized the earliest, mainly the obligate aerobes Enterobacter and Pseudomonas, followed by the obligate anaerobes (Clostridium hathewayi and Veillonella parvula) and the facultative anaerobe Clostridium ramosum in Firmicutes, and Verrucomicrobia. Actinobacteria colonized the latest, mainly Bifidobacterium, and gradually became dominant bacteria.

CONCLUSIONSDuring infancy, obligate aerobes colonize the intestinal tract the earliest, followed by obligate anaerobes and facultative anaerobes. Proteobacteria colonizes the earliest, followed by Firmicutes and Verrucomicrobia, and Actinobacteria, mainly Bifidobacterium, colonizes the latest.

Denaturing Gradient Gel Electrophoresis ; methods ; Feces ; microbiology ; Female ; Gastrointestinal Microbiome ; Humans ; Infant ; Male ; Polymerase Chain Reaction ; methods

We measured physiological functionalities, including antihypertensive angiotensin I-converting enzyme inhibitory activity and immun-stimulating beta-glucan content for sixty kinds of Makgeolli that is commercially available from the market. As a result, we selected R-12 commercial raw Makgeolli, with a high content of immuno-stimulating beta-glucan, and R-14 commercial raw Makgeolli, exhibiting high antihypertensive activity. Due to the similarities in their overall physicochemical properties and raw materials used for fermentation, we compared the microbial flora in order to investigate the reason for the differences in their functionalities. Nested PCR and denaturing gradient gel electrophoresis for yeasts and bacteria were performed for analysis of microbial diversity of two different kinds of Makgeolli (i.e., R-12, R-14), which showed immuno-stimulating beta-glucan content and exhibited a very high level of antihypertensive activity, respectively. Analysis of the 18S rDNA amplicon revealed a major presence of the yeast strain Pichia burtonii in every Makgeolli sample. Analysis of the 16S rDNA amplicon revealed a predominance of lactic acid bacteria, and the most frequent lactic acid bacteria were Lactobacillus ingluviei, L. fermentum, and L. harbinensis, and Lactobacillus sp. Among these, L. harbinensis was detected only in R-12 and L. ingluviei was found only in R-14. Different functionalities from the individual commercially available Makgeolli may be attributed to actions of different microbial flora during fermentation.
Bacteria ; Denaturing Gradient Gel Electrophoresis ; DNA, Ribosomal ; Fermentation ; Lactic Acid ; Lactobacillus ; Peptidyl-Dipeptidase A ; Pichia ; Polymerase Chain Reaction ; Sprains and Strains ; Yeasts

OBJECTIVETo analyze the differences between the oral microbiota of monozygotic and dizygotic twins by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE).

METHODSA total of 20 pairs of twin children were included in this study, in which 10 pairs were monozygotic (MZ) twins, and 10 pairs were dizygotic (DZ) twins. Of the 20 pairs, 10 pairs of twins had primary dentition, and 10 pairs had mixed dentition; 17 children had caries, and 23 children had no caries. Genomic DNA was extracted from saliva samples. The 16s rRNA was amplified and analyzed by PCR-DGGE. The PCR-DGGE band number and Shannon index were calculated.

RESULTSCluster analysis showed high similarity in the oral bacterial community seen in co-twins. However, no significant difference was seen between MZ and DZ twins. In the primary dentition, the PCR-DGGE band number and Shannon index of children with caries (11.00 +/- 1.56, 1.05 +/- 0.36) were lower than those of children without caries (14.00 +/- 2.74, 1.44 +/- 0.37) (P < 0.05). In mixed dentition, the PCR-DGGE band number and Shannon index of children with caries (11.88 +/- 4.05, 1.18 +/- 0.36) were lower than those of children without caries (14.31 +/- 5.71, 1.28 +/- 0.47), but the differences were not statistically significant (P > 0.05).

CONCLUSIONEnvironmental factors may have a stronger effect on the constitution of oral microbiota in children compared with genetic factors. Children without caries may have a richer microbial diversity compared with children with caries.

Bacteria ; Child ; Denaturing Gradient Gel Electrophoresis ; Dental Caries ; Female ; Humans ; Male ; Microbiota ; Mouth ; microbiology ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S ; Saliva ; Twins, Monozygotic

OBJECTIVETo analyze the differences between the bacterial diversities in the saliva of caries-free and caries-susceptible adolescents through polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE).

METHODSTwenty adolescent subjects aged 12-18 years were recruited and subdivided into two groups: caries-free adolescents (n = 10) and caries-susceptible adolescents (n = 10). Saliva samples were collected. Total DNA was isolated directly from each sample. A portion of the 16S rRNA gene locus was PCR-amplified by using universal primers. Microbial diversity was analyzed through PCR-DGGE.

RESULTSAnalyzing the DGGE profile, we found that the composition of the saliva microbiome exhibited great intra-individual differences; the average band numbers of the caries-free adolescent group and the caries-susceptible adolescent group were 32.5 ± 3.7 and 27.3 ± 3.4, respectively. The differences between the groups were statistically significant (P = 0.008). Shannon-Wiener's indexes of the caries-susceptible adolescent group and the caries-free adolescent group were 2.5 ± 0.2 and 2.6 ± 0.2, respectively, but the differences between the groups were not significant (P = 0.405). Clustering analysis results suggested that most of the samples in the same group clustered together; this observation showed a high community structure similarity.

CONCLUSIONThe microbial diversity and complexity of bacteria in saliva are significantly higher in caries-free adolescents than in caries-susceptible adolescents. During caries development, bacterial diversity in the saliva likely decreases.

Adolescent ; Bacteria ; Child ; DNA, Bacterial ; analysis ; Denaturing Gradient Gel Electrophoresis ; Dental Caries ; microbiology ; Dental Caries Susceptibility ; Humans ; Microbiota ; Mouth ; microbiology ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S ; Saliva ; microbiology

OBJECTIVETo examine allelic frequencies of coding single nucleotide polymorphisms (cSNPs) of folypolyglutamate synthetase (FPGS) gene in Chinese Han children with acute leukemia (AL), in order to provide a basis for detecting the relationship between FPGS genetic polymorphisms and tumor individualized chemotherapy.

METHODScSNPs of exon 5 were detected with polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE) in 91 children with AL and 124 children with upper respiratory infection as controls. Genotypes and allelic frequencies were examined.

RESULTSA novel missense mutation, 502/490 T>C (L151/101P), was found in exon 5 of FPGS from control children. The novel mutation was found in mitochondrial variants in two cases and cytosolic variants in three cases. The cytosolic and mitochondrial variants displayed allelic frequencies of 0.70 % and 0.47 % respectively. The novel mutation was not associated with susceptibility to AL.

CONCLUSIONSA novel missense mutation 502/490 T>C (L151/101P) in exon 5 of FPGS gene is firstly found in Chinese Han children, and the cytosolic and mitochondrial variants display allelic frequencies of 0.70 % and 0.47 % respectively.

Child ; Child, Preschool ; Denaturing Gradient Gel Electrophoresis ; Exons ; Female ; Humans ; Infant ; Male ; Methotrexate ; pharmacology ; Mutation, Missense ; Peptide Synthases ; genetics ; Polymorphism, Single Nucleotide ; Sequence Analysis, DNA

In order to reveal the cause of disease occurred in the process of Coptis chinensis growth, this paper studied the bacterial species diversity index of different aged rhizospheric and non-rhizospheric soil planting normal or sick C. chinensis by using PCR-DGGE technique. The representative DGGE bands were chosen to be cloned, and sequenced, the phylogeny were constructed. The results showed that the bacterial communities were very different between the normal and diseased soil samples of C. chinensis, and the diversity index (H) of diseased soil samples were higher than that of normal soil samples. Sequencing analysis of representative cloned DGGE bands showed that the unculturable bacteria were the dominant groups, and bacteria belonged to genus Bacillus, Acidovorax, Acinetobacter, uncultured Kluyvera, and uncultured Comamonas were also existing, but the reported plant pathogenic bacteria were not found in the C. chinensis planting soil. The density and brightness of clone band d in diseased soil samples was higher than that in normal soil sample, and sequencing analysis showed that it belonged to genus Acidovorax. Obviously, during the process of C. chinensis growth, the rhizospheric bacteria population changed, and the quantity of bacteria belong Acidovorax increased, which probably resulted in the disease occurred during C. chinensis growth.
Bacteria ; classification ; genetics ; isolation & purification ; Biodiversity ; Coptis ; growth & development ; microbiology ; Denaturing Gradient Gel Electrophoresis ; Molecular Sequence Data ; Phylogeny ; Polymerase Chain Reaction ; Rhizosphere ; Soil Microbiology

Information on co-adherence of different oral bacterial species is important for understanding interspecies interactions within oral microbial community. Current knowledge on this topic is heavily based on pariwise coaggregation of known, cultivable species. In this study, we employed a membrane binding assay coupled with polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) to systematically analyze the co-adherence profiles of oral bacterial species, and achieved a more profound knowledge beyond pairwise coaggregation. Two oral bacterial species were selected to serve as "bait": Fusobacterium nucleatum (F. nucleatum) whose ability to adhere to a multitude of oral bacterial species has been extensively studied for pairwise interactions and Streptococcus mutans (S. mutans) whose interacting partners are largely unknown. To enable screening of interacting partner species within bacterial mixtures, cells of the "bait" oral bacterium were immobilized on nitrocellulose membranes which were washed and blocked to prevent unspecific binding. The "prey" bacterial mixtures (including known species or natural saliva samples) were added, unbound cells were washed off after the incubation period and the remaining cells were eluted using 0.2 mol x L(-1) glycine. Genomic DNA was extracted, subjected to 16S rRNA PCR amplification and separation of the resulting PCR products by DGGE. Selected bands were recovered from the gel, sequenced and identified via Nucleotide BLAST searches against different databases. While few bacterial species bound to S. mutans, consistent with previous findings F. nucleatum adhered to a variety of bacterial species including uncultivable and uncharacterized ones. This new approach can more effectively analyze the co-adherence profiles of oral bacteria, and could facilitate the systematic study of interbacterial binding of oral microbial species.
Adult ; Animals ; Bacterial Adhesion ; DNA, Bacterial ; analysis ; Denaturing Gradient Gel Electrophoresis ; Fusobacterium nucleatum ; physiology ; Humans ; Membranes, Artificial ; Mice ; Microbial Interactions ; physiology ; Polymerase Chain Reaction ; Protein Binding ; Saliva ; microbiology ; Streptococcus mutans ; physiology