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Natural Product Reports Mar 2024Covering: up to the end of 2022In recent years rare Actinobacteria have become increasingly recognised as a rich source of novel bioactive metabolites. are... (Review)
Review
Covering: up to the end of 2022In recent years rare Actinobacteria have become increasingly recognised as a rich source of novel bioactive metabolites. are Gram-positive bacteria that occupy a wide range of ecological niches. This review highlights about 230 secondary metabolites produced by spp., reported until the end of 2022, including their bioactivities and selected biosynthetic pathways. Notably, the bioactive compounds produced by spp. demonstrate a wide range of activities, including antimicrobial, antitumor and anticoccidial effects, highlighting their potential in various fields.
Topics: Actinomadura; Actinobacteria; Anti-Infective Agents; Bacteria; Biology
PubMed: 38099919
DOI: 10.1039/d3np00047h -
Bacterial Microbiome Differences between the Roots of Diseased and Healthy Chinese Hickory () Trees.Journal of Microbiology and... Oct 2023is an important economic nut tree that is endemic to eastern China. As such, outbreaks of root rot disease in result in reduced yields and serious economic losses....
is an important economic nut tree that is endemic to eastern China. As such, outbreaks of root rot disease in result in reduced yields and serious economic losses. Moreover, while soil bacterial communities play a crucial role in plant health and are associated with plant disease outbreaks, their diversity and composition in are not clearly understood. In this study, Proteobacteria, Acidobacteria, and Actinobacteria were found to be the most dominant bacterial communities (accounting for approximately 80.32% of the total) in the root tissue, rhizosphere soil, and bulk soil of healthy specimens. Further analysis revealed the abundance of genera belonging to Proteobacteria, namely, , , , , and , was higher in the root tissues of healthy specimens than in those of diseased and dead trees. In addition, the abundance of four genera belonging to Actinobacteria, namely, , , , and , was significantly higher in the root tissues of healthy specimens than in those of diseased and dead trees. Altogether, these results suggest that disruption in the balance of these bacterial communities may be associated with the development of root rot in , and further, our study provides theoretical guidance for the isolation and control of pathogens and diseases related to this important tree species.
Topics: Actinobacteria; Bacteria; Carya; Gammaproteobacteria; Microbiota; Plant Roots; Proteobacteria; Rhizosphere; Soil; Soil Microbiology; Trees
PubMed: 37528558
DOI: 10.4014/jmb.2304.04054 -
Fitoterapia Mar 2024Actinomadura sp., which is usually found in muddy habitats, produces various secondary metabolites with biological activities. In this study, five new compounds named...
Actinomadura sp., which is usually found in muddy habitats, produces various secondary metabolites with biological activities. In this study, five new compounds named formosensin A (1), formosensin B (2), oxanthroquinone-3-O-α-d-mannose (8), oxanthromicin A (9), and oxanthromicin B (10) were isolated from the culture of Actinomadura sp. together with five known compounds (3-7). Their structures were elucidated by extensive spectroscopic methods including NMR and MS. In particular, the absolute configurations of compounds 1 and 2 were determined using computational methods. Moreover, compounds 1-2 and 8-10 were screened for cytotoxic activity using a panel of human tumor cell lines. Compound 9 induced significant cytotoxicity in five human tumor cell lines (HL-60, A-549, SMMC-7721, MCF-7, and SW480) with IC values of 8.7, 17.5, 15.0, 17.8, and 14.6 μM, respectively. These findings suggested that compound 9 could provide therapeutic benefits in the treatment of tumor-related diseases.
Topics: Humans; Actinomadura; Molecular Structure; Antineoplastic Agents; Cell Line, Tumor; Anthraquinones
PubMed: 38181893
DOI: 10.1016/j.fitote.2023.105806 -
Microbial Ecology Nov 2023Soil microorganisms play important roles in vegetation establishment and soil biogeochemical cycling. Ammodendron bifolium is a dominant sand-fixing (i.e., stabilizing...
The Composition and Diversity of the Rhizosphere Bacterial Community of Ammodendron bifolium Growing in the Takeermohuer Desert Are Different from Those in the Nonrhizosphere.
Soil microorganisms play important roles in vegetation establishment and soil biogeochemical cycling. Ammodendron bifolium is a dominant sand-fixing (i.e., stabilizing sand dunes) and endangered plant in the Takeermohuer Desert, and the bacterial community associated with this plant rhizosphere is still unclear. In this study, we investigated the composition and diversity of the bacterial community from the A. bifolium rhizosphere and bulk soil at different soil depths (i.e., 0-40 cm, 40-80 cm, 80-120 cm) using culture and high-throughput sequencing methods. We preliminarily analyzed the edaphic factors influencing the structure of bacterial communities. The results showed that the high-salinity Takeermohuer Desert has an oligotrophic environment, while the A. bifolium rhizosphere exhibited a relatively nutrient-rich environment due to higher contents of soil organic matter (SOM) and soil alkaline nitrogen (SAN) than bulk soil. The dominant bacterial groups in the desert were Actinobacteria (39.8%), Proteobacteria (17.4%), Acidobacteria (10.2%), Bacteroidetes (6.3%), Firmicutes (6.3%), Chloroflexi (5.6%), and Planctomycetes (5.0%) at the phylum level. However, the relative abundances of Proteobacteria (20.2%) and Planctomycetes (6.1%) were higher in the rhizosphere, and those of Firmicutes (9.8%) and Chloroflexi (6.9%) were relatively higher in barren bulk soil. A large number of Actinobacteria were detected in all soil samples, of which the most abundant genera were Streptomyces (5.4%) and Actinomadura (8.2%) in the bulk soil and rhizosphere, respectively. The Chao1 and PD_whole_tree indices in the rhizosphere soil were significantly higher than those in the bulk soil at the same soil depth and tended to decrease with increasing soil depth. Co-occurrence network analyses showed that the keystone species in the Takeermohuer Desert were the phyla Actinobacteria, Acidobacteria, Proteobacteria, and Chloroflexi. Furthermore, the major edaphic factors affecting the rhizosphere bacterial community were electrical conductivity (EC), SOM, soil total nitrogen (STN), SAN, and soil available potassium (SAK), while the major edaphic factors affecting the bacterial community in bulk soil were distance and ratio of carbon to nitrogen (C/N). We concluded that the A. bifolium rhizosphere bacterial community is different from that of the nonrhizosphere in composition, structure, diversity, and driving factors, which may improve our understanding of the relationship between plant and bacterial communities and lay a theoretical foundation for A. bifolium species conservation in desert ecosystems.
Topics: Ecosystem; Rhizosphere; Bacteria; Proteobacteria; Acidobacteria; Fabaceae; Soil; Plants; Nitrogen; Soil Microbiology
PubMed: 38008827
DOI: 10.1007/s00248-023-02320-9 -
Journal of Xenobiotics Aug 2023The decomposition of biodegradable composite carbon sources generates a large amount of biodegradable microplastics, which may not only furnish microbial...
The decomposition of biodegradable composite carbon sources generates a large amount of biodegradable microplastics, which may not only furnish microbial denitrification, but might also pose potential environmental risks. In the present study, the effects of different dosages of a biodegradable composite carbon source on the microbial communities, the nitrogen metabolic pathways and the antibiotic resistome were explored through Illumina MiSeq sequencing analysis and metagenomic analysis. The results of partial least-square discriminant analysis (PLS-DA) and analysis of similarity (ANOSIM) demonstrated that the response of the bacterial community to a biodegradable composite carbon source was more obvious than the fungal community. The application of biodegradable microplastics diminished the complexity of the microbial communities to some extent and obviously stimulated denitrification. Antibiotics resistance gene (ARG) dispersal was not evidently accelerated after the addition of biodegradable composite carbon source. , , , , from and , , and from were the major ARG hosts. Overall, the addition of a biodegradable composite carbon source shaped microbial communities and their antibiotic resistance profiles in this study.
PubMed: 37606424
DOI: 10.3390/jox13030027 -
Microbial Ecology Nov 2023Soil microorganisms play important roles in vegetation establishment and soil biogeochemical cycling. Ammodendron bifolium is a dominant sand-fixing and endangered plant...
Composition and Distribution Characteristics of Rhizosphere Bacterial Community of Ammodendron bifolium Growing in Takeermohuer Desert Are Different from Those in Non-rhizosphere.
Soil microorganisms play important roles in vegetation establishment and soil biogeochemical cycling. Ammodendron bifolium is a dominant sand-fixing and endangered plant in Takeermohuer Desert, and bacterial community associated with this plant rhizosphere is still unclear. In this study, we studied the composition and diversity of bacterial community from A. bifolium rhizosphere and bulk soil at different soil depths (i.e., 0-40 cm, 40-80 cm, 80-120 cm) using traditional bacterial isolation and high-throughput sequencing approaches, and preliminarily analyzed the edaphic factors influencing the structure of bacterial communities. Results showed that Takeermohuer Desert with high salinity has been an oligotrophic environment, while the rhizosphere exhibited eutrophication resulting from high content SOM (soil organic matter) and SAN (soil alkaline nitrogen) compared with bulk soil. The dominant bacterial groups in the desert were Actinobacteria (39.8%), Proteobacteria (17.4%), Acidobacteria (10.2%), Bacteroidetes (6.3%), Firmicutes (6.3%), Chloroflexi (5.6%), and Planctomycetes (5.0%) at the phyla level. However, the relative abundances of Proteobacteria (20.2%) and Planctomycetes (6.1%) were higher in eutrophic rhizosphere, and Firmicutes (9.8%) and Chloroflexi (6.9%) relatively higher in barren bulk soil. A large number of Actinobacteria were detected in all soil samples, of which the most abundant genus was Streptomyces (5.4%) and Actinomadura (8.2%) in the bulk soil and rhizosphere, respectively. The Chao1 and PD indexes in rhizosphere were significantly higher than those in bulk soil at the same soil depth, and tended to decrease with increasing soil depth. Co-occurrence network analyses showed that the keystone species in Takeermohuer Desert were Actinobacteria, Acidobacteria, Proteobacteria, and Chlorofexi. Furthermore, the major environmental factors affecting rhizosphere bacterial community were EC (electrical conductivity), SOM, STN (soil total nitrogen), SAN, and SAK (soil available potassium), while bulk soil were distance and C/N (STC/STN). We concluded that A. bifolium rhizosphere bacterial community is different from non-rhizosphere in composition, distribution, and environmental influencing factors, which will have important significances for understanding their ecological functions and maintaining biodiversity.
Topics: Rhizosphere; Bacteria; Proteobacteria; Acidobacteria; Fabaceae; Soil; Nitrogen; Soil Microbiology
PubMed: 37301781
DOI: 10.1007/s00248-023-02252-4 -
The Science of the Total Environment Jul 2023The addition of Arbuscular mycorrhizal fungi (AMF) or bioorganic fertilizer (BOF) alone has been reported to enhance plant tolerance to heavy metals and salt stress and...
Synergistic mechanisms of bioorganic fertilizer and AMF driving rhizosphere bacterial community to improve phytoremediation efficiency of multiple HMs-contaminated saline soil.
The addition of Arbuscular mycorrhizal fungi (AMF) or bioorganic fertilizer (BOF) alone has been reported to enhance plant tolerance to heavy metals and salt stress and promote plant growth, while their synergistic effects on plant growth and rhizosphere microorganism are largely unknown. This study explored the effects of AMF (Rhizophagus intraradices), BOF and BOF + RI assisted phytoremediation on heavy metals contaminated saline soil improvement and revealed the microbial mechanism. For this purpose, a pot trial consisting of four treatments (CK, RI, BOF and BOF + RI) was carried out. The results showed that the biomass, nutrient element contents, the accumulation of heavy metals and Na of Astragalus adsurgens and soil properties were most significantly improved by BOF + RI. BOF + RI significantly impacted rhizosphere microbial diversity, abundance and community composition. Chloroflexi and Patescibacteria at the phylum level and Actinomadura, Iamia, and Desulfosporosinus at the genus level were significantly enriched in BOF + RI. Network analysis revealed that BOF + RI significantly changed the keystone and enhanced complexity and interaction. Most of the keystones had roles in promoting plant growth and stress resistance. This study suggested that phytoremediation assisted by BOF and AMF is an attractive approach to ameliorate heavy metals contaminated saline soil.
Topics: Mycorrhizae; Fertilizers; Biodegradation, Environmental; Rhizosphere; Metals, Heavy; Bacteria; Soil; Soil Pollutants; Soil Microbiology; Plant Roots
PubMed: 37105481
DOI: 10.1016/j.scitotenv.2023.163708 -
Environmental Pollution (Barking, Essex... Aug 2023The potential of sulphur (S), MgSO (Mg), and KHPO (P) in nitrogen retention, ammonia emission decrease, and microbial community succession during composting needs to be...
The potential of sulphur (S), MgSO (Mg), and KHPO (P) in nitrogen retention, ammonia emission decrease, and microbial community succession during composting needs to be investigated. To achieve this, different levels of S (0, 0.2, 0.4, 0.6, and 0.8% in dry weight) plus Mg and P (S + Mg + P) were progressively added in 70 days pig manure aerobic composting. The results revealed that the amendment increased salinity and lowered pH and dephytotoxication of the product with the increase of S amount. However, no significant inhibition effects were observed on the evolution of the thermophilic phase and product maturity. In addition, the amendment significantly reduced the total NH and NO emissions by 29.66%-58.81% and 20.6%-56.7%, increased NH level by 17.22%-73.21% in thermophilic phase and NO content by 26.17%-57.48% in a mature phase, and elevated the total Kjeldahl nitrogen content by 34.28%-46.6% during the composting. In addition, compared to the control, the supplement markedly encouraged the formation of guanite in the compost product. The S addition stimulated the growth of Anseongella, Actinomadura, Chelativorans, Castellaniella, Luteimonas, and Steroidobacter microbial communities which functioned well in the degradation of nitrogen-containing compounds and organic matter. Evidence from Redundancy Analysis, Firmicutes, Myxococcus, Chloroflexi, Gemmatimonadota, and Deinococcota showed positive correlations with pH. These results imply that adding S-Mg-P amendment encourages the population and activity of specific functional microorganisms, and facilitated the ammonia emission reduction by lowering pH and thus reserved nitrogen through the formation of guanite during composting. The investigation of bacterial community abundance and environmental variables at the phylum and genus levels over time revealed that adding of 0.6% S in conjunction with P and Mg minerals was suitable for nitrogen loss mitigation in composting. The findings suggest using S + Mg + P supplement to conserve nitrogen in pig dung aerobic composting.
Topics: Swine; Animals; Ammonia; Manure; Composting; Soil; Nitrogen; Sulfur; Bacteria
PubMed: 37263560
DOI: 10.1016/j.envpol.2023.121934 -
International Journal of Molecular... Dec 2023Madurastatins are a group of pentapeptides containing an oxazoline moiety, and, in a few cases, an imidazolidinone ring as an additional structural feature. In our...
Madurastatins are a group of pentapeptides containing an oxazoline moiety, and, in a few cases, an imidazolidinone ring as an additional structural feature. In our search for new potential antiparasitic metabolites from natural sources, we studied the acetone extracts from a culture of sp. CA-135719. The LC/HRMS analysis of this extract identified the presence of the known madurastatins C1 (), D1 (), and D2 () together with additional members of the family that were identified as the new madurastatins H2 () and 33--D1 () after isolation and spectroscopic analysis. The planar structures of the new compounds were established by HRMS, ESI-qTOF-MS/MS, and 1D and 2D NMR data, and their absolute configuration was proposed using Marfey's and bioinformatic analyses of the biosynthetic gene cluster (BGC). A revision of the absolute configuration of madurastatins D1 and D2 is proposed. Additionally, madurastatins containing imidazolidinone rings are proved to be artifacts originating during acetone extraction of the bacterial cultures.
Topics: Solvents; Acetone; Biological Products; Tandem Mass Spectrometry; Antiparasitic Agents
PubMed: 38203471
DOI: 10.3390/ijms25010301 -
Environmental Microbiology Dec 2023The herbicide glyphosate has several potential entry points into composting sites and its impact on composting processes has not yet been evaluated. To assess its impact...
The herbicide glyphosate has several potential entry points into composting sites and its impact on composting processes has not yet been evaluated. To assess its impact on bacterial diversity and abundance as well as on community composition and dynamics, we conducted a mesocosm experiment at the Montreal Botanical Garden. Glyphosate had no effect on physicochemical property evolution during composting, while it was completely dissipated by the end of the experiment. Sampling at Days 0, 2, 28 and 112 of the process followed by 16S rRNA amplicon sequencing also found no effect of glyphosate on species richness and community composition. Differential abundance analyses revealed an increase of a few taxa in the presence of glyphosate, namely TRA3-20 (order Polyangiales), Pedosphaeraceae and BIrii41 (order Burkholderiales) after 28 days. In addition, five amplicon sequence variants (ASVs) had lower relative abundance in the glyphosate treatment compared to the control on Day 2, namely Comamonadaceae, Pseudomonas sp., Streptomyces sp., Thermoclostridium sp. and Actinomadura keratinilytica, while two ASVs were less abundant on Day 112, namely Pedomicrobium sp. and Pseudorhodoplanes sp. Most differences in abundance were measured between the different sampling points within each treatment. These results present glyphosate as a poor determinant of species recruitment during composting.
Topics: Glyphosate; Composting; RNA, Ribosomal, 16S; Herbicides; Streptomyces
PubMed: 36975075
DOI: 10.1111/1462-2920.16374