Soil contains a great diversity of microorganisms, among which are bacteria. This study aimed to explore bacterial diversity in soil samples in Brazzaville in the Republic of the Congo. Environmental DNA was extracted...Soil contains a great diversity of microorganisms, among which are bacteria. This study aimed to explore bacterial diversity in soil samples in Brazzaville in the Republic of the Congo. Environmental DNA was extracted. The illumina MiSeq sequencing was held and the diversity indices have been computed. Illumina MiSeq sequencing revealed 21 Phyla, four of which were abundant: Proteobacteria, Acidobacteria, Actinobacteria and Bacteroidetes. Soil microbial communities in the studied samples were phylogenetically diverse but with a stable community structure. 17 classes are represented with relative abundances of Rihzobiales, Bacillales, Actinomycetales and Acidobacteriales. 40 families, the Alphaproteobacteria, the Bacilli and the 12 Actinobacteria. 83 orders among which the Rhizobiales are the most abundant followed by Bacillales and the least abundant followed by the Flavobacteriaceae. Of the 28 genera listed, the Bradyrhizobium is the most dominant in Mw3 and Mw4. 25 listed species, Bradyrhizobium, Bacillus, Actinoplanes, and Candidatu coribacter Acidobacterium are the most abundant species. The Shannon indices of Mw3 and Mw4 are equal, the H’max of Mw4 is greater than the H’max of Mw3. The Simpson index of Mw4 is equal to the Simpson index of Mw3, and the Pielou index (J) of Mw4 is less than the R of Mw3, but very close. This study opens interesting perspectives on the knowledge and exploitation of telluric bacteria in several areas of life.展开更多
Pectinases, the enzymes which break down pectic substances, have a wide range of applications in food, agriculture and environmental sectors. In the present study, attempts were made to isolate highly efficient pectin...Pectinases, the enzymes which break down pectic substances, have a wide range of applications in food, agriculture and environmental sectors. In the present study, attempts were made to isolate highly efficient pectinase producer from the rhizosphere of a medicinal plant, Andrographis paniculata Nees, known as the “King of bitters”. The total heterotrophic bacterial count of the rhizosphere soil of A. paniculata Nees ranged from 1.53 × 109 to 2.52 × 109 cfu/g. A total of 65 bacterial colonies were randomly selected from the nutrient agar plates, purified and assessed for pectinase activity. Out of the 65 isolates, 62 (95.38%) showed varying degree of pectinase activity in plate assay using pectin as a sole source of carbon. Among the pectinase producing strains, JBST36 showed best pectinase activity which is followed by the JBST22 and JBST27. Morphological characterization, biochemical tests and 16S rRNA gene sequencing were performed to identify the three most potential strains. Based on the morphological, biochemical and molecular data, JBST22 was identified as Bacillus flexus and the other two were identified as Bacillus subtilis. Furthermore, nucleotide sequences of the 16S rRNA gene of these 3 strains were compared and a phylogenetic tree was constructed. The study reveals that there are at least 66 base differences in the 16S rRNA gene sequences of B. flexus JBST22 and the B. subtilis JBST36.展开更多
Although the gut microflora is thought to be an essential factor in the development of ulcerative colitis (UC), the entire gut microflora occurring in UC remains unknown. Most studies use feces to represent the microf...Although the gut microflora is thought to be an essential factor in the development of ulcerative colitis (UC), the entire gut microflora occurring in UC remains unknown. Most studies use feces to represent the microflora distribution;however, here we analyzed the bacterial diversity in colonic mucus from UC patients receiving colectomy surgery and control patients. The diversity of microflora was investigated using a combination of terminal restriction fragment length polymorphism (T-RFLP) and clone library analyses of the 16S rRNA gene sequences. In the T-RFLP analysis, the number of terminal restriction fragments (T-RFs) decreased significantly in UC patients when compared to control samples. Also in the clone library analysis, the number of operational taxonomic units (OTU) and the Shannon diversity index were reduced significantly in UC patients. These molecular analyses reveal an overall dysbiosis in UC patients. No specific pathogen was found, and a strong negative correlation in relative abundance of bacterial populations was observed between the phyla Bacteroidetes and Firmicutes in the UC patients. This is the first report showing a significant correlation between these two phyla, which may be important characteristics in the pathogenesis of UC.展开更多
A strain of gram-positive bacillus was isolated from suppurative lung organs of nursery pigs in a pig farm, which was further characterized by morphological observation, cultivation test, biochemical test, drug sensit...A strain of gram-positive bacillus was isolated from suppurative lung organs of nursery pigs in a pig farm, which was further characterized by morphological observation, cultivation test, biochemical test, drug sensitivity test, pathogenicity test and 16S rDNA gene cloning and sequence analysis. The results showed that the isolate grew well in rabbit blood agar plate and horse serum tryptone soybean agar （TSA） plate under aerobic condition, which could lead to mortality of mice and were susceptible to cephalosporin antibiotics and fluoroquinolone antibiotics. Phylogenetic analysis showed that the isolate had close genetic evolutionary relationships with Corynebacterium bacteria, and the sequence of 16S rRNA gene shared the homology of 91.7% -98.3% with the representative strain of coryne- bacteria, indicating the isolated strain was eorynebactefium.展开更多
文摘Soil contains a great diversity of microorganisms, among which are bacteria. This study aimed to explore bacterial diversity in soil samples in Brazzaville in the Republic of the Congo. Environmental DNA was extracted. The illumina MiSeq sequencing was held and the diversity indices have been computed. Illumina MiSeq sequencing revealed 21 Phyla, four of which were abundant: Proteobacteria, Acidobacteria, Actinobacteria and Bacteroidetes. Soil microbial communities in the studied samples were phylogenetically diverse but with a stable community structure. 17 classes are represented with relative abundances of Rihzobiales, Bacillales, Actinomycetales and Acidobacteriales. 40 families, the Alphaproteobacteria, the Bacilli and the 12 Actinobacteria. 83 orders among which the Rhizobiales are the most abundant followed by Bacillales and the least abundant followed by the Flavobacteriaceae. Of the 28 genera listed, the Bradyrhizobium is the most dominant in Mw3 and Mw4. 25 listed species, Bradyrhizobium, Bacillus, Actinoplanes, and Candidatu coribacter Acidobacterium are the most abundant species. The Shannon indices of Mw3 and Mw4 are equal, the H’max of Mw4 is greater than the H’max of Mw3. The Simpson index of Mw4 is equal to the Simpson index of Mw3, and the Pielou index (J) of Mw4 is less than the R of Mw3, but very close. This study opens interesting perspectives on the knowledge and exploitation of telluric bacteria in several areas of life.
文摘Pectinases, the enzymes which break down pectic substances, have a wide range of applications in food, agriculture and environmental sectors. In the present study, attempts were made to isolate highly efficient pectinase producer from the rhizosphere of a medicinal plant, Andrographis paniculata Nees, known as the “King of bitters”. The total heterotrophic bacterial count of the rhizosphere soil of A. paniculata Nees ranged from 1.53 × 109 to 2.52 × 109 cfu/g. A total of 65 bacterial colonies were randomly selected from the nutrient agar plates, purified and assessed for pectinase activity. Out of the 65 isolates, 62 (95.38%) showed varying degree of pectinase activity in plate assay using pectin as a sole source of carbon. Among the pectinase producing strains, JBST36 showed best pectinase activity which is followed by the JBST22 and JBST27. Morphological characterization, biochemical tests and 16S rRNA gene sequencing were performed to identify the three most potential strains. Based on the morphological, biochemical and molecular data, JBST22 was identified as Bacillus flexus and the other two were identified as Bacillus subtilis. Furthermore, nucleotide sequences of the 16S rRNA gene of these 3 strains were compared and a phylogenetic tree was constructed. The study reveals that there are at least 66 base differences in the 16S rRNA gene sequences of B. flexus JBST22 and the B. subtilis JBST36.
文摘Although the gut microflora is thought to be an essential factor in the development of ulcerative colitis (UC), the entire gut microflora occurring in UC remains unknown. Most studies use feces to represent the microflora distribution;however, here we analyzed the bacterial diversity in colonic mucus from UC patients receiving colectomy surgery and control patients. The diversity of microflora was investigated using a combination of terminal restriction fragment length polymorphism (T-RFLP) and clone library analyses of the 16S rRNA gene sequences. In the T-RFLP analysis, the number of terminal restriction fragments (T-RFs) decreased significantly in UC patients when compared to control samples. Also in the clone library analysis, the number of operational taxonomic units (OTU) and the Shannon diversity index were reduced significantly in UC patients. These molecular analyses reveal an overall dysbiosis in UC patients. No specific pathogen was found, and a strong negative correlation in relative abundance of bacterial populations was observed between the phyla Bacteroidetes and Firmicutes in the UC patients. This is the first report showing a significant correlation between these two phyla, which may be important characteristics in the pathogenesis of UC.
基金Supported by Research Project of Guangxi Bureau of Fishery Sciences and Animal Husbandry and Veterinary(GYMK 12049031,1304522)Research Project of Xixiangtang District in Nanning City(2014304,2014302)Systematic Research Project for Key Laboratory of Livestock and Poultry Vaccine New Technology in Guangxi Province(12-071-28-A-5)
文摘A strain of gram-positive bacillus was isolated from suppurative lung organs of nursery pigs in a pig farm, which was further characterized by morphological observation, cultivation test, biochemical test, drug sensitivity test, pathogenicity test and 16S rDNA gene cloning and sequence analysis. The results showed that the isolate grew well in rabbit blood agar plate and horse serum tryptone soybean agar （TSA） plate under aerobic condition, which could lead to mortality of mice and were susceptible to cephalosporin antibiotics and fluoroquinolone antibiotics. Phylogenetic analysis showed that the isolate had close genetic evolutionary relationships with Corynebacterium bacteria, and the sequence of 16S rRNA gene shared the homology of 91.7% -98.3% with the representative strain of coryne- bacteria, indicating the isolated strain was eorynebactefium.
