scholarly journals Soil bacterial community structure in five tropical forests in Malaysia and one temperate forest in Japan revealed by pyrosequencing analyses of 16S rRNA gene sequence variation

2013 ◽  
Vol 88 (2) ◽  
pp. 93-103 ◽  
Author(s):  
Naohiko T. Miyashita ◽  
Hiroko Iwanaga ◽  
Suliana Charles ◽  
Bibian Diway ◽  
John Sabang ◽  
...  
2020 ◽  
Author(s):  
Zhiyuan Gao ◽  
Yaya Hu ◽  
Meikun Han ◽  
Junjie Xu ◽  
Xue Wang ◽  
...  

Abstract Background: Continuous cropping obstacles from sweet potato are widespread, which seriously reduce the yield and quality, cause certain economic losses. Bacteria of Rhizospheric soil are the richest and are associated with obstacles to continuous cropping. However, few studies on how continuous sweet potato cropping affects the rhizospheric soil bacterial community structure. In the study, Illumina Miseq method was used to explore rhizosphere soil bacterial community structure changes with different sweet potato varieties, and the correlation between soil characteristics and this bacterial community after continuous cropping, to provide theoretical guidance for prevention and treatment of sweet potatoes continuous cropping obstacles. Results: After continuous cropping two years, the results showed that (1) the dominant bacterial phlya in rhizospheric soils from both Xushu18 and Yizi138 were Proteobacteria, Acidobacteria, and Actinobacteria. The most dominant genus was Subgroup 6_norank. The relative abundance of rhizospheric soil bacteria of two sweet potato varieties changed significantly. (2) The richness and diversity indexes of bacteria in Xushu18 rhizospheric soil were higher than those from Yizi138 after continuous cropping. Moreover, the beneficial Lysobacter and Bacillus were more prevalent in Xushu18, but Yizi138 contained more harmful Gemmatimonadetes. (3) Soil pH decreased after continuous cropping, and redundancy analysis result indicated that soil pH was correlated significantly with bacterial community. Spearman’s rank correlations coefficients analysis demonstrated that pH was positively associated with Planctomycetes and Acidobacteria, but negatively associated with Actinobacteria and Firmicutes.Conclusions: After continuous cropping, the bacterial community structure and physicochemical properties of sweet potato rhizospheric soil were unbalanced, and the changes from different sweet potato varieties were different. The contents of Lysobacter and Bacillus were higher in the sweet potato variety resistant to continuous cropping. It provides a basis for developing new microbial fertilizer for sweet potatoes to alleviate continuous cropping obstacle.


2010 ◽  
Vol 76 (24) ◽  
pp. 8117-8125 ◽  
Author(s):  
Paul J. Hunter ◽  
Paul Hand ◽  
David Pink ◽  
John M. Whipps ◽  
Gary D. Bending

ABSTRACT Morphological and chemical differences between plant genera influence phyllosphere microbial populations, but the factors driving within-species variation in phyllosphere populations are poorly understood. Twenty-six lettuce accessions were used to investigate factors controlling within-species variation in phyllosphere bacterial populations. Morphological and physiochemical characteristics of the plants were compared, and bacterial community structure and diversity were investigated using terminal restriction fragment length polymorphism (T-RFLP) profiling and 16S rRNA gene clone libraries. Plant morphology and levels of soluble carbohydrates, calcium, and phenolic compounds (which have long been associated with plant responses to biotic stress) were found to significantly influence bacterial community structure. Clone libraries from three representative accessions were found to be significantly different in terms of both sequence differences and the bacterial genera represented. All three libraries were dominated by Pseudomonas species and the Enterobacteriaceae family. Significant differences in the relative proportions of genera in the Enterobacteriaceae were detected between lettuce accessions. Two such genera (Erwinia and Enterobacter) showed significant variation between the accessions and revealed microbe-microbe interactions. We conclude that both leaf surface properties and microbial interactions are important in determining the structure and diversity of the phyllosphere bacterial community.


Author(s):  
Chen Zheng-li ◽  
Peng Yu ◽  
Wu Guo-sheng ◽  
Hong Xu-Dong ◽  
Fan Hao ◽  
...  

Abstract Burns destroy the skin barrier and alter the resident bacterial community, thereby facilitating bacterial infection. To treat a wound infection, it is necessary to understand the changes in the wound bacterial community structure. However, traditional bacterial cultures allow the identification of only readily growing or purposely cultured bacterial species and lack the capacity to detect changes in the bacterial community. In this study, 16S rRNA gene sequencing was used to detect alterations in the bacterial community structure in deep partial-thickness burn wounds on the back of Sprague-Dawley rats. These results were then compared with those obtained from the bacterial culture. Bacterial samples were collected prior to wounding and 1, 7, 14, and 21 days after wounding. The 16S rRNA gene sequence analysis showed that the number of resident bacterial species decreased after the burn. Both resident bacterial richness and diversity, which were significantly reduced after the burn, recovered following wound healing. The dominant resident strains also changed, but the inhibition of bacterial community structure was in a non-volatile equilibrium state, even in the early stage after healing. Furthermore, the correlation between wound and environmental bacteria increased with the occurrence of burns. Hence, the 16S rRNA gene sequence analysis reflected the bacterial condition of the wounds better than the bacterial culture. 16S rRNA sequencing in the Sprague-Dawley rat burn model can provide more information for the prevention and treatment of burn infections in clinical settings and promote further development in this field.


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