Figure - available from: Archives of Microbiology
This content is subject to copyright. Terms and conditions apply.
Source publication
Actinomycetales is an order of actinobacteria that have an important role in the decomposition of organic matter. Their abundance and distribution can reflect a good level of soil fertility as well as biological activity. In this research study, actinomycetal diversity in soil was investigated under various field treatments with biowastes. Initiall...
Citations
... For instance, sludge is the semi-solid organic by-product of the wastewater treatment process (Mohajerani et al., 2019). Depending on the origin and composition of the raw wastewater, sludge can be high in organic carbon, plant nutrients, and beneficial microorganisms (Fytili and Zabaniotou, 2008;Zoghlami et al., 2016;Mokni-Tlili et al., 2020). In this regard, millions of metric tons of urban and industrial sludges generated worldwide may be subjected to land application in the most cost-effective way (Rosazlin et al., 2015;Hamdi et al., 2019;Kogbara et al., al., 2020a;2020b). ...
... Both norank_o_Acidobacteriales and Xanthobacteraceae can grow in acidic soils [49], and their adaptability to pH could allow them to become significantly enriched in the rhizosphere soils of Luvisols. Nocardioidaceae is a family of Actinomycetes that can produce a variety of antibiotics and play an important role in soil improvement [50]. This taxon is mostly concentrated in extreme environments such as saline and alkaline areas [51]. ...
The rhizosphere microbiome is closely related to forest health and productivity. However, whether soil type affects pecan (Carya illinoinensis) rhizosphere microbiomes is unclear. We aimed to explore the diversity and structural characteristics of rhizosphere bacteria associated with pecan plantations grown in three soil types (Luvisols, Cambisols, Solonchaks) in Eastern China and analyze their potential functions through high-throughput sequencing. The results showed that the diversity and community structure of rhizosphere bacteria in pecan plantations were significantly affected by soil type and the pH, available phosphorus content, electrical conductivity, soil moisture, and ammonium nitrogen contents were the main factors. At the phylum level, the rhizosphere bacterial community composition was consistent, mainly included Actinobacteria, Proteobacteria, Acidobacteria, and Chloroflexi. At the family level, the pecan plantations formed different rhizosphere enriched biomarkers due to the influence of soil type, with functional characteristics such as plant growth promotion and soil nutrient cycling. In addition, there existed low abundance core species such as Haliangiaceae, Bryobacteraceae, and Steroidobacteraceae. They played important roles in the rhizosphere environments through their functional characteristics and community linkages. Overall, this study provides a basis for the study of the rhizosphere microbiome in different soil types of pecan plantations, and plays an important role in the sustainable management of forest soil.
... The fire-affected soils with burned wood maintenance presented higher contents of nutrients and a more stable structure than the soil under SL management, which was associated with a greater abundance of microorganisms with the ability to degrading the organic matter compounds. In this sense, the presence of Actinomycetales (Actinobacteria) in C soils was highly representative thanks to their important role in decomposition of labile (Goldfarb et al., 2011) and recalcitrant organic substances (Mokni-Tlili et al., 2020). Families found as relevant were Streptosporangiaceae as cellulose destructor (Wei et al., 2020), the Microbacteriaeae as lignocellulose decomposer (Argiroff et al., 2019); and the Coriobacteriaceae both labile carbon and cellulose decomposer (Goldfarb et al., 2011). ...
Salvage logging is one of the most common post-fire management strategies, known for trigger soil degradation processes. Soil compaction, the major disturbance associated with logging operations, could seriously hamper the resilience of soil microorganisms after the perturbation produced by fire. The main objective of this work was to assess the impact of post-fire salvage logging on the composition and structure of soil bacterial and fungi communities, as well as to correlate these findings with the changes in soil physicochemical properties. The management severely affected the soil physicochemical and microbial properties. Whereas an increase of alpha diversity was detected in the treated soils for the microbial community, the microbial functionality registered was lower when compared to control soils. Salvage logging profoundly altered the structure and composition of the microbial communities, being modifications in soil structure the main driver in the microbial community shifts. Soil degradation induced by logging operations resulted in new niches related to anoxic habitats, being Proteobacteria and Firmicutes families, capable of anaerobic respiration, families with high abundance in the affected soils. In addition, the depletion in C and N nutrients as a consequence of the soil erosion reduced the microbial populations sensitive to substrates availability, e.g. Actinomycetales. Ascomycota increased proportionally in managed soils, which might be due to the removal of host plants dependent on ectomycorrhizal fungi. This study demonstrated that physical soil disturbance performed by the post-fire salvage logging profoundly impacted the soil microbial community and associated functions. A deeper understanding of the relationship between disturbances caused by forest management and resilience of soil biodiversity is required.
... The shared OTUs were affiliated to Actinobacteria (Actinomycetales, 0319-7L14, Gaiellales orders) and Proteobacteria (Rhodospirillales, MND1 orders) phyla, which are commonly detected as dominant phyla in agricultural soil (Delgado-Baquerizo et al. 2018). Interestingly, the OTUs related to the Actinobacteria 0319-7L14 order, detected in both rhizospheric and nonrhizospheric soils (Fig. 3a,b), have been reported as rhizospheric actinobacteria (Muratova et al. 2020) and their abundance being affected by Regarding Actinobacteria, an OTU shared by rhizospheric soils was related to Actinomycetales order (Fig. 3a), which members have been recognized as organic matter (polysaccharides) decomposer (Yeager et al. 2017;Mokni-Tlili et al. 2020) that might explain its presence in the rhizospheric soil. While the OTU related to the Gaiellales order, shared by nonrhizospheric soils (Fig. 3b), has been shown negatively affected by root exudates (Szoboszlay et al. 2016). ...
We described the bacterial diversity of walnut grove soils under organic and conventional farming. The bacterial communities of rhizospheric and non‐rhizospheric soils of pecan tree (Carya illinoensis K. Koch) were compared considering two phenological stages (sprouting and ripening). Sixteen OTUs were identified significantly more abundant according to the plant development, only one according to the farming condition, and none according to the soil origin. The OTUs specificaly abundant according to plant development included Actinobateria (2) and Betaproteobacteria (1) related OTUs more abundant at the sprouting stage, while at the fruit ripening stage the more abundant OTUs were related to Actinobacteria (6), Alphaproteobacteria (6), and unclassified Bacteria (1). The Gaiellaceae OTU18 (Actinobacteria) was more abundant under conventional farming. Thus, our study revealed that the plant development stage was the main factor shaping the bacterial community structure, while less influence was noticed for the farming condition. The bacterial communities exhibited specific metabolic capacities, a large range of carbon sources being used at the fruit ripening stage. The identified OTUs specifically more abundant represent indicators providing useful information on soil condition, potential tools for the management of soil bacterial communities.
2 Manure composting on cultivated fields can disseminate antimicrobial resistance into plants 3 which are either consumed raw or slightly altered before consumption. There is rising evidence 4 to examine the impacts on antibiotic resistance genes (ARGs) quantity and diversity in the 5 agricultural fields with the manure application, yet little attention has been given to the 6 comprehensive descriptions of environmental antibiotic resistance abatement with various 7 management strategies. Here, an integrated-omics method integrating Illumina sequencing and 8 metagenomics analysis was used to explore the effects of crop rotation system and plant species 9 on antibiotic resistance genes (ARGs) and the bacterial communities in manure amended 10 rhizosphere soil. The findings indicated that manure treatment and crop rotation had a major 11 impact on bacterial community composition, while bacterial diversity was affected by 12 manure but not crop rotation and plant species. Quantitative PCR methods revealed that the 13 manure treatment significantly increased the abundance of two sulfamethazine (sulI, sulII), one 14 tetracycline (tetA), and one sulfonamide (sul1) resistance genes while the crop rotation and plant 15 species had reduced the prevalence of resistance genes in every cycle. Metagenomic sequencing 16 of both samples exhibited a significant difference in the types, and abundance of antibiotics 17 resistance genes and mobile genetic elements. The host tracking analysis revealed the influence 18 of agricultural management on bacterial/ARGs networks, although MS and OS systems respond 19 differently to the agricultural management strategies. We found that the bacterial/ARGs network 20 of the MS system was affected by both crop rotation and plant species while no impact was 21 observed of the management strategies on the OS system. These results suggest that management 22 practices interact differently with manured and unmanured soil to shape rhizosphere microbial This preprint research paper has not been peer reviewed. Electronic copy available at: https://ssrn.com/abstract=4062571 P r e p r i n t n o t p e e r r e v i e w e d 2 23 community composition and significantly influencing the soil resistome delivering valuable 24 perspective to improve agroecosystem sustainability. 25
