Erratum to: Paenibacillus beijingensis sp. nov., a nitrogen-fixing species isolated from wheat rhizosphere soil

Summary Nematode communities in the soils of wheat (Triticum aestivum Linn.) rhizosphere grown alone and grown in jujube (Ziziphus jujuba Mill.) orchard were investigated for three years in Hetian arid area, Xingjiang Uygur Autonomous Region, northwest of China. The results showed that eu-dominant families were Rhabditidae, Cephalobidae and Aphelenchidae among 15 families and 19 genera. Nematode abundance in wheat rhizosphere soil was smaller in wheat/jujube intercropping system, mainly because of lower numbers of bacterial feeders and fungal feeders. Besides, the nematode numbers of cp-1 and cp-2 (cp, colonizer-persister) guilds were significantly lower in wheat/jujube intercropping system than that in monoculture wheat system, due to the markedly lower numbers of Rhabditidae and Cephalobidae, although those of cp-3 and cp-4 guilds had no significant differences between monoculture and intercropping systems. Shannon-Weaver index (H’), genus dominance index (Ig) and structural index (SI), represented soil food web diversity and structure, had no differences between monoculture and intercropping systems. Significantly lower values of Wasilewska index (WI) and PPI/MI in monoculture wheat than in intercropping system. It was concluded that the soil status in monoculture wheat system exhibited better soil ecosystem in compared with wheat/ jujube intercropping system.

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Research on Improvement of Nitrogenase Activity of Free-Living Nitrogen-Fixing Bacteria Using DBD Plasma

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.671-674.2674 ◽

2013 ◽

Vol 671-674 ◽

pp. 2674-2678 ◽

Cited By ~ 1

Author(s):

Yan Yun Zhu ◽

Xiao Li Zhu ◽

Fang She Yang

Keyword(s):

Rhizosphere Soil ◽

Barrier Discharge ◽

Nitrogenase Activity ◽

Nitrogen Fixing ◽

Bacterial Strains ◽

Dbd Plasma ◽

Nitrogen Fixing Bacteria ◽

Free Living ◽

Reduction Assay ◽

Rrna Sequencing

Nitrogen-fixing bacteria were screened from the rhizosphere soil of plants in Shaanxi in China. 36 free-living nitrogen-fixing bacterial strains were isolated and their nitrogenase activity were determined by acetylene reduction assay (ARA), two strains named FLNB03 and FLNB09 with higher nitrogenase activity were isolated and identified by 16S rRNA sequencing. The datum showed that FLNB03 was similar to Acinetobacter and their similarity reached 99%, FLNB09 was similar to Agrobacterium sp. and their similarity reached 99%. Then both of them were treated using Dielectric Barrier Discharge (DBD) plasma for mutation and their mutants called FLNB03-2 and FLNB09-3 were obtained. The nitrogenase activity of FLNB03-2 was 0.61±0.10 nmol•107cfu-1•h-1, and that of FLNB09-3 was 0.40±0.05 nmol•107cfu-1•h-1, their nitrogenase activity increased by 22.00% and 14.29% than their original bacteria respectively. FLNB03-2 and FLNB09-3 might be used as microbial fertilizer.

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STUDIES ON THE RELATIONSHIPS BETWEEN NEMATODES AND OTHER SOIL MICROORGANISMS: IV. INCIDENCE OF NEMATODE-TRAPPING FUNGI IN THE VICINITY OF PLANT ROOTS

Canadian Journal of Microbiology ◽

10.1139/m65-064 ◽

1965 ◽

Vol 11 (3) ◽

pp. 491-495 ◽

Cited By ~ 19

Author(s):

E. A. Peterson ◽

H. Katznelson

Keyword(s):

Soil Microorganisms ◽

Rhizosphere Soil ◽

Red Clover ◽

Root Surface ◽

Plant Roots ◽

Favorable Effect ◽

Bacterial Isolates ◽

Rhizosphere Effect ◽

Root Extracts ◽

Wheat Rhizosphere

A study was made of the occurrence of nematode-trapping fungi in the rhizosphere and on the root surface of different plants. Arthrobotrys oligospora was the predominant predaceous fungus isolated. It was almost completely absent from plant roots but occurred in varying frequency in rhizosphere soil and in root-free soil. The incidence of this fungus was consistently greater in the soybean rhizosphere and lower in the wheat rhizosphere than in corresponding soil devoid of roots, whereas for other plants, red clover, flax, etc., there was no obvious rhizosphere effect. Spore germination tests and growth of A. oligospora in root extracts of soybeans and wheat failed to account for the differences observed. However, bacterial isolates from the wheat rhizosphere were, on the whole, more antagonistic to this fungus than those from the soybean rhizosphere, whereas isolates from the latter appeared to exert a favorable effect.

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High-methionine soybean has no significant effect on nitrogen-transforming bacteria in rhizosphere soil

Plant Soil and Environment ◽

10.17221/750/2017-pse ◽

2018 ◽

Vol 64 (No. 3) ◽

pp. 108-113 ◽

Cited By ~ 2

Author(s):

Liang Jingang ◽

Luan Ying ◽

Jiao Yue ◽

Sun Shi ◽

Wu Cunxiang ◽

...

Keyword(s):

Community Composition ◽

Rhizosphere Soil ◽

Microbial Community Composition ◽

Potential Effect ◽

Ammonia Oxidizing Bacteria ◽

Nitrogen Fixing ◽

Transgenic Soybean ◽

Bacterial Populations ◽

Microbial Functional Groups ◽

Microbial Groups

Transgenic plants may induce shifts in the microbial community composition that in turn alter microbially-mediated nutrient cycling in soil. Studies of how specific microbial groups respond to genetically modified (GM) planting help predict potential impacts upon processes performed by these groups. This study investigated the effect of transgenic high-methionine soybean cv. ZD91 on nitrogen-fixing and ammonia-oxidizing bacterial populations. A difference in nitrogen-fixing or ammonia-oxidizing bacteria community composition was not found, suggesting that cv. ZD91 does not alter the bacterial populations in rhizosphere soil. This study increases our understanding of the potential effect of transgenic soybean on microbial functional groups within soil by suggesting that nitrogen-transforming bacteria may be useful for future investigations on the GM crops impact in the soil ecosystem.

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The Influence of the Host Plant Is the Major Ecological Determinant of the Presence of Nitrogen-Fixing Root Nodule Symbiont Cluster II Frankia Species in Soil

Applied and Environmental Microbiology ◽

10.1128/aem.02661-16 ◽

2016 ◽

Vol 83 (1) ◽

Cited By ~ 3

Author(s):

Kai Battenberg ◽

Jannah A. Wren ◽

Janell Hillman ◽

Joseph Edwards ◽

Liujing Huang ◽

...

Keyword(s):

Host Plant ◽

Host Plants ◽

Root Nodule ◽

Rhizosphere Soil ◽

Broad Host Range ◽

Nitrogen Fixing ◽

Content Type ◽

Microbiome Analysis ◽

Α Diversity ◽

Significant Difference

ABSTRACT The actinobacterial genus Frankia establishes nitrogen-fixing root nodule symbioses with specific hosts within the nitrogen-fixing plant clade. Of four genetically distinct subgroups of Frankia, cluster I, II, and III strains are capable of forming effective nitrogen-fixing symbiotic associations, while cluster IV strains generally do not. Cluster II Frankia strains have rarely been detected in soil devoid of host plants, unlike cluster I or III strains, suggesting a stronger association with their host. To investigate the degree of host influence, we characterized the cluster II Frankia strain distribution in rhizosphere soil in three locations in northern California. The presence/absence of cluster II Frankia strains at a given site correlated significantly with the presence/absence of host plants on the site, as determined by glutamine synthetase (glnA) gene sequence analysis, and by microbiome analysis (16S rRNA gene) of a subset of host/nonhost rhizosphere soils. However, the distribution of cluster II Frankia strains was not significantly affected by other potential determinants such as host-plant species, geographical location, climate, soil pH, or soil type. Rhizosphere soil microbiome analysis showed that cluster II Frankia strains occupied only a minute fraction of the microbiome even in the host-plant-present site and further revealed no statistically significant difference in the α-diversity or in the microbiome composition between the host-plant-present or -absent sites. Taken together, these data suggest that host plants provide a factor that is specific for cluster II Frankia strains, not a general growth-promoting factor. Further, the factor accumulates or is transported at the site level, i.e., beyond the host rhizosphere. IMPORTANCE Biological nitrogen fixation is a bacterial process that accounts for a major fraction of net new nitrogen input in terrestrial ecosystems. Transfer of fixed nitrogen to plant biomass is especially efficient via root nodule symbioses, which represent evolutionarily and ecologically specialized mutualistic associations. Frankia spp. (Actinobacteria), especially cluster II Frankia spp., have an extremely broad host range, yet comparatively little is known about the soil ecology of these organisms in relation to the host plants and their rhizosphere microbiomes. This study reveals a strong influence of the host plant on soil distribution of cluster II Frankia spp.

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STUDIES ON THE INTERACTION OF PLANTS AND FREE-LIVING NITROGEN-FIXING MICROORGANISMS: II. DEVELOPMENT OF ANTAGONISTS OF AZOTOBACTER IN THE RHIZOSPHERE OF PLANTS AT DIFFERENT STAGES OF GROWTH IN TWO SOILS

Canadian Journal of Microbiology ◽

10.1139/m61-060 ◽

1961 ◽

Vol 7 (4) ◽

pp. 507-513 ◽

Cited By ~ 10

Author(s):

E. Strzelczyk

Keyword(s):

Organic Matter ◽

Rhizosphere Soil ◽

Sandy Loam ◽

Organic Matter Content ◽

Matter Content ◽

Nitrogen Fixing ◽

Free Living ◽

Stages Of Growth ◽

Central Experimental Farm

This study represents an attempt to correlate the low numbers of Azotobacter in rhizosphere and root-free soils at the Central Experimental Farm, Ottawa, with the incidence of bacterial and actinomycete antagonists of this organism. Wheat, radish, and onion were grown in the greenhouse in two soils varying greatly in fertility and organic matter content, and isolations of bacteria and actinomycetes were made periodically for testing against Azotobacter. It was found that rhizosphere soil contained greater numbers of microorganisms antagonistic to Azotobacter than root-free soil. Of the three crops used wheat exerted the least effect. In all the tests numbers of antagonists were greater in the fertile Granby sandy loam than in the infertile Upland sand. The results correlated well with the Azotobacter populations in these soils as reported in the first paper of this series.

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Phylogenetic diversity of nitrogen-fixing bacteria and thenifHgene from mangrove rhizosphere soil

Canadian Journal of Microbiology ◽

10.1139/w2012-016 ◽

2012 ◽

Vol 58 (4) ◽

pp. 531-539 ◽

Cited By ~ 16

Author(s):

Jianyin Liu ◽

Mengjun Peng ◽

Youguo Li

Keyword(s):

Phylogenetic Trees ◽

Rhizosphere Soil ◽

Nifh Gene ◽

Soil Samples ◽

Community Diversity ◽

Nitrogen Fixing ◽

Pcr Cloning ◽

Nitrogen Fixing Bacteria ◽

Soil Dna ◽

Mangrove Ecosystems

Nine types of nitrogen-fixing bacterial strains were isolated from 3 rhizosphere soil samples taken from mangrove plants in the Dongzhaigang National Mangrove Nature Reserve of China. Most isolates belonged to Gammaproteobacteria Pseudomonas , showing that these environments constituted favorable niches for such abundant nitrogen-fixing bacteria. New members of the diazotrophs were also found. Using a soil DNA extraction and PCR-cloning-sequencing approach, 135 clones were analyzed by restriction fragment length polymorphism (RFLP) analysis, and 27 unique nifH sequence phylotypes were identified, most of which were closely related to sequences from uncultured bacteria. The diversity of nitrogen-fixing bacteria was assessed by constructing nifH phylogenetic trees from sequences of all isolates and clones in this work, together with related nifH sequences from other mangrove ecosystems in GenBank. The nifH diversity varied among soil samples, with distinct biogeochemical properties within a mangrove ecosystem. When comparing different mangrove ecosystems, the nifH gene sequences from a specific site tended to cluster as individual groups. The results provided interesting data and novel information on our understanding of diazotroph community diversity in the mangrove ecosystems.

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