scholarly journals Seasonal changes in bacterial communities associated with healthy and diseasedPoritescoral in southern Taiwan

2016 ◽  
Vol 62 (12) ◽  
pp. 1021-1033 ◽  
Author(s):  
Chorng-Horng Lin ◽  
Chih-Hsiang Chuang ◽  
Wen-Hung Twan ◽  
Shu-Fen Chiou ◽  
Tit-Yee Wong ◽  
...  

We compared the bacterial communities associated with healthy scleractinian coral Porites sp. with those associated with coral infected with pink spot syndrome harvested during summer and winter from waters off the coast of southern Taiwan. Members of the bacterial community associated with the coral were characterized by means of denaturing gradient gel electrophoresis (DGGE) of a short region of the 16S rRNA gene and clone library analysis. Of 5 different areas of the 16S rRNA gene, we demonstrated that the V3 hypervariable region is most suited to represent the coral-associated bacterial community. The DNA sequences of 26 distinct bands extracted from DGGE gels and 269 sequences of the 16S rRNA gene from clone libraries were determined. We found that the communities present in diseased coral were more heterogeneous than the bacterial communities of uninfected coral. In addition, bacterial communities associated with coral harvested in the summer were more diverse than those associated with coral collected in winter, regardless of the health status of the coral. Our study suggested that the compositions of coral-associated bacteria communities are complex, and the population of bacteria varies greatly between seasons and in coral of differing health status.

2020 ◽  
Vol 11 ◽  
Author(s):  
Pasquale Alibrandi ◽  
Sylvia Schnell ◽  
Silvia Perotto ◽  
Massimiliano Cardinale

The endophytic microbiota can establish mutualistic or commensalistic interactions within the host plant tissues. We investigated the bacterial endophytic microbiota in three species of Mediterranean orchids (Neottia ovata, Serapias vomeracea, and Spiranthes spiralis) by metabarcoding of the 16S rRNA gene. We examined whether the different orchid species and organs, both underground and aboveground, influenced the endophytic bacterial communities. A total of 1,930 operational taxonomic units (OTUs) were obtained, mainly Proteobacteria and Actinobacteria, whose distribution model indicated that the plant organ was the main determinant of the bacterial community structure. The co-occurrence network was not modular, suggesting a relative homogeneity of the microbiota between both plant species and organs. Moreover, the decrease in species richness and diversity in the aerial vegetative organs may indicate a filtering effect by the host plant. We identified four hub OTUs, three of them already reported as plant-associated taxa (Pseudoxanthomonas, Rhizobium, and Mitsuaria), whereas Thermus was an unusual member of the plant microbiota. Core microbiota analysis revealed a selective and systemic ascent of bacterial communities from the vegetative to the reproductive organs. The core microbiota was also maintained in the S. spiralis seeds, suggesting a potential vertical transfer of the microbiota. Surprisingly, some S. spiralis seed samples displayed a very rich endophytic microbiota, with a large number of OTUs shared with the roots, a situation that may lead to a putative restoring process of the root-associated microbiota in the progeny. Our results indicate that the bacterial community has adapted to colonize the orchid organs selectively and systemically, suggesting an active involvement in the orchid holobiont.


2021 ◽  
Vol 6 (2) ◽  
pp. 61-85
Author(s):  
Miguel A. García-Muñoz ◽  
◽  
Nancy Cruz-Velazco ◽  
América Chávez-Martínez ◽  
Cirilo Nolasco-Hipólito ◽  
...  

The population of the Papaloapan region consume artisan fresh cheeses and no pathogen outbreaks have been reported recently. The microbiota is responsible to develop desirable characteristics of cheeses and undesirable characteristics due to the presence of certain pathogens microorganisms. Therefore, to identify the microorganisms of fresh cheeses is an important issue for the producers, consumers, and authorities. 11 Artisan fresh cheese samples from the Papaloapan region were collected in the summer and 11 samples in winter to characterize their microbiota. Traditional microbial techniques were used to identify the fungus and the amplification of the 16S rRNA gene and PCR-denaturing gradient gel electrophoresis (DGGE) The population of the Papaloapan region consume artisan fresh cheeses and no pathogen outbreaks have been reported recently. The microbiota is responsible to develop desirable characteristics of cheeses and undesirable characteristics due to the presence of certain pathogens microorganisms. Therefore, to identify the microorganisms of fresh cheeses is an important issue for the producers, consumers, and authorities. 11 Artisan fresh cheese samples from the Papaloapan region were collected in the summer and 11 samples in winter to characterize their microbiota. Traditional microbial techniques were used to identify the fungus and the amplification of the 16S rRNA gene and PCR-denaturing gradient gel electrophoresis (DGGE) The population of the Papaloapan region consume artisan fresh cheeses and no pathogen outbreaks have been reported recently. The microbiota is responsible to develop desirable characteristics of cheeses and undesirable characteristics due to the presence of certain pathogens microorganisms. Therefore, to identify the microorganisms of fresh cheeses is an important issue for the producers, consumers, and authorities. 11 Artisan fresh cheese samples from the Papaloapan region were collected in the summer and 11 samples in winter to characterize their microbiota. Traditional microbial techniques were used to identify the fungus and the amplification of the 16S rRNA gene and PCR-denaturing gradient gel electrophoresis (DGGE) method was used for bacteria identification. For all the samples, the presence of aerobic mesophiles, Streptococcus mesophiles and thermophiles, Lactobacillus mesophiles, Leuconostoc, total coliforms, Staphylococcus aureus, molds, and yeasts were identified. The complexity and variety of microorganisms in the summer and winter seasons samples were not significantly different. In conclusion, all samples of fresh artisan cheeses were under high microbial loads. Lactic Acid Bacteria (LAB) were in a typical load, as established by the quality and safety standards in the food industry. Conversely, pathogenic bacteria exceeded this limit. The microorganisms present in the fresh artisanal cheeses of the Papaloapan region were identified with precision, regarding the count and their diversity. A recommendation for the cheese manufacturers is to prepare starter cultures by selecting the appropriate microorganisms to produce the desirable characteristics such as aroma and flavor and reduce the risk of microbial infections by using pasteurized milk.


2008 ◽  
Vol 13 (3) ◽  
pp. 97-102 ◽  
Author(s):  
HIROKI MATSUI ◽  
RIE TSUCHIYA ◽  
YUKA ISOBE ◽  
HIROTO MAEDA ◽  
MIYO NARITA

2020 ◽  
Vol 96 (2) ◽  
Author(s):  
Ben Ma ◽  
Timothy M LaPara ◽  
Ashley N. Evans ◽  
Raymond M Hozalski

ABSTRACT Spatial patterns of bacterial community composition often follow a distance–decay relationship in which community dissimilarity increases with geographic distance. Such a relationship has been commonly observed in natural environments, but less so in engineered environments. In this study, bacterial abundance and community composition in filter media samples (n = 57) from full-scale rapid biofilters at 14 water treatment facilities across North America were determined using quantitative polymerase chain reaction and Illumina HiSeq high-throughput sequencing targeting the 16S rRNA gene, respectively. Bacteria were abundant on the filter media (108.8±0.3 to 1010.7±0.2 16S rRNA gene copies/cm3 bed volume) and the bacterial communities were highly diverse (Shannon index: 5.3 ± 0.1 to 8.4 ± 0.0). Significant inter-filter variations in bacterial community composition were observed, with weighted UniFrac dissimilarity values following a weak but highly significant distance–decay relationship (z = 0.0057 ± 0.0006; P = 1.8 × 10−22). Approximately 50% of the variance in bacterial community composition was explained by the water quality parameters measured at the time of media sample collection (i.e. pH, temperature and dissolved organic carbon concentration). Overall, this study suggested that the microbiomes of biofilters are primarily shaped by geographic location and local water quality conditions but the influence of these factors on the microbiomes is tempered by filter design and operating conditions.


2005 ◽  
Vol 71 (7) ◽  
pp. 4144-4148 ◽  
Author(s):  
Sebastian R. Sørensen ◽  
Jim Rasmussen ◽  
Carsten S. Jacobsen ◽  
Ole S. Jacobsen ◽  
René K. Juhler ◽  
...  

ABSTRACT A bacterial community from Danish agricultural soil was enriched with linuron [N-(3,4-dichlorophenyl)-N′-methoxy-N′-methylurea] as the sole carbon and nitrogen source. The community mineralized [ring-U-14C]linuron completely to 14CO2 and 14C-biomass. Denaturing gradient gel electrophoresis analysis and cultivation revealed that a Variovorax sp. was responsible for the mineralization activity.


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