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Frontiers in Microbiology 2024While spent mushroom substrate (SMS) has shown promise in increasing soil organic carbon (SOC) and improving soil quality, research on the interplay between SOC...
While spent mushroom substrate (SMS) has shown promise in increasing soil organic carbon (SOC) and improving soil quality, research on the interplay between SOC components and microbial community following the application of diverse SMS types remains scant. A laboratory soil incubation experiment was conducted with application of two types of SMSs from cultivation of (PE) and (AB), each at three application rates (3, 5.5, and 8%). Advanced techniques, including solid-state C nuclear magnetic resonance (NMR) and high-throughput sequencing, were employed to investigate on SOC fractions and chemical structure, microbial community composition and functionality. Compared to SMS-AB, SMS-PE application increased the relative abundances of carbohydrate carbon and O-alkyl C in SOC. In addition, SMS-PE application increased the relative abundance of the bacterial phylum Proteobacteria and those of the fungal phyla Basidiomycota and Ascomycota. The relative abundances of cellulose-degrading bacterial (e.g., and ) and fungal genera (e.g., , , and ) were increased as well. The application of SMS-AB increased the aromaticity index of SOC, the relative abundance of aromatic C, and the contents of humic acid and heavy fraction organic carbon. In addition, SMS-AB application significantly increased the relative abundances of the bacterial phyla Firmicutes and Actinobacteria. Notably, the genera , , and , which were positively correlated with humic acid, experienced an increase in relative abundance. Functional prediction revealed that SMS-PE application elevated carbohydrate metabolism and reduced the prevalence of fungal pathogens, particularly . The application of high-rate SMS-AB (8%) enhanced bacterial amino acid metabolism and the relative abundances of plant pathogenic fungi. Our research provides strategies for utilizing SMS to enrich soil organic carbon and fortify soil health, facilitating the achievement of sustainable soil management.
PubMed: 38827156
DOI: 10.3389/fmicb.2024.1351921 -
Environmental Research Jul 2024The aim of this study was to assess effects of MnO addition (CK-0%, T1-2% and T2-5%) on humification and bacterial community during municipal sludge (MS) composting. The...
The aim of this study was to assess effects of MnO addition (CK-0%, T1-2% and T2-5%) on humification and bacterial community during municipal sludge (MS) composting. The results suggested that MnO addition inhibited the growth of Nitrospira but stimulated Nonomuraea, Actinomadura, Streptomyces and Thermopolyspora, facilitating the lignocellulose degradation and humification with the increase in organic matter degradation by 13.8%-19.2% and humic acid content by 10.9%-20.6%. Compared to CK, the abundances of exoglucanase (EC:3.2.1.91), endo-1,4-beta-xylanase (EC:3.2.1.136) and endomannanase (EC:3.2.1.78) increased by 88-99, 52-66 and 4-15 folds, respectively. However, 5%-MnO induced the enrichment of Mizugakiibacter that harms the environment of agricultural production. The addition of 2%-MnO was recommended for MS composting. Furthermore, metabolic function analysis indicated that MnO addition altered amino acid and carbohydrate metabolism, especially enhancing propanoate metabolism and butanoate metabolism but inhibiting citrate cycle. Structural equation modeling revealed that Nonomuraea and Actinomadura were the main drivers for lignocellulose degradation. This study provided theoretical guidance in regulating humification via MnO for MS composting.
Topics: Composting; Waste Disposal, Fluid; Soil Microbiology; Biodegradation, Environmental; Soil; Actinobacteria; Actinomadura; Streptomyces; Humic Substances
PubMed: 38754608
DOI: 10.1016/j.envres.2024.119151 -
Journal of Natural Products May 2024A chemical investigation of Australian soil-derived bacteria sp. S4S-00069B08 yielded eight new benzenoid ansamycins, goondansamycins A-H. Goondansamycins feature rare...
A chemical investigation of Australian soil-derived bacteria sp. S4S-00069B08 yielded eight new benzenoid ansamycins, goondansamycins A-H. Goondansamycins feature rare 1,4-benzoxazin-3-one or -diamino--benzoquinone moieties and can exist as both aglycones or 9--α-glycosides of either d-rhodinose or d-amicetose. Structures were solved on the basis of detailed spectroscopy, including X-ray analysis.
Topics: Australia; Molecular Structure; Soil Microbiology; Actinomadura; Benzoquinones; Crystallography, X-Ray
PubMed: 38747559
DOI: 10.1021/acs.jnatprod.4c00336 -
Antimicrobial Agents and Chemotherapy May 2024Mycetoma is a devastating neglected tropical infection of the subcutaneous tissues. It is caused by fungal and bacterial pathogens recognized as eumycetoma and...
Mycetoma is a devastating neglected tropical infection of the subcutaneous tissues. It is caused by fungal and bacterial pathogens recognized as eumycetoma and actinomycetoma, respectively. Mycetoma treatment involves diagnosing the causative microorganism as a prerequisite to prescribing a proper medication. Current therapy of fungal eumycetoma causative agents, such as , consists of long-term antifungal medication with itraconazole followed by surgery, yet with usually unsatisfactory clinical outcomes. Actinomycetoma, on the contrary, usually responds to treatment with co-trimoxazole and amikacin. Therefore, there is a pressing need to discover novel broad-spectrum antimicrobial agents to circumvent the time-consuming and costly diagnosis. Using the resazurin assay, a series of 23 naphthylisoquinoline (NIQ) alkaloids and related naphthoquinones were subjected to screening against two fungal strains of and three bacterial strains of and . Seven NIQs, mostly dimers, showed promising activities against at least one strain of the mycetoma-causative pathogens, while the naphthoquinones did not show any activity. A synthetic NIQ dimer, 8,8'''-,-dimethylmichellamine A (), inhibited all tested fungal and bacterial strains (IC = 2.81-12.07 µg/mL). One of the dimeric NIQs, michellamine B (), inhibited a strain of and significantly enhanced the survival rate of larvae infected with at concentrations of 1 and 4 µg/mL, without being toxic to the uninfected larvae. As a result, broad-spectrum dimeric NIQs like and with antimicrobial activity are considered hit compounds that could be worth further optimization to develop novel lead antimycetomal agents.
Topics: Mycetoma; Antifungal Agents; Animals; Alkaloids; Microbial Sensitivity Tests; Madurella; Isoquinolines; Actinomadura; Naphthoquinones; Larva; Moths
PubMed: 38602413
DOI: 10.1128/aac.01612-23 -
International Journal of Microbiology 2024complex (MTBC) is a group of bacteria responsible for causing tuberculosis in animals and humans. In South Africa (S.A), slaughterhouses are registered by the...
complex (MTBC) is a group of bacteria responsible for causing tuberculosis in animals and humans. In South Africa (S.A), slaughterhouses are registered by the government and closely inspected and audited for hygienic slaughter practices. Meat inspection to detect lesions has been used for passive surveillance, monitoring, and diagnosis of the disease status. Information on the current status of bovine tuberculosis (bTB) in livestock in the country is limited. Hence, we investigated the occurrence of spp. in the tissues of slaughtered livestock and environmental samples in abattoirs in Gauteng province of South Africa (S.A). The cross-sectional study employing random sampling from cattle, pigs, and sheep (with the collection of liver, lung, spleen, and different lymph nodes) irrespective of lesions was carried out in 19 red meat abattoirs. Five hundred animals were sampled, comprising cattle ( = 369), pigs ( = 90), and sheep ( = 41). Additionally, 19 environmental samples were collected from feedlots, or where animals drink water while awaiting slaughter, to identify mycobacterial species using culture, acid-fast bacteria staining, and polymerase chain reaction (PCR). The Chi-square and Fisher's Exact tests were used to detect statistically significant differences in the frequency of detection of spp. according to the variables investigated (types of tissues, livestock, abattoirs, etc.). The PCR assays detected no MTBC complex species DNA in the bacterial isolates from cattle ( = 32). Sequence analysis (16S rDNA) of the isolates from eight cattle confirmed only two species, namely (99.81% identity) and (99.42% identity). The remaining isolates were identified as members of the species. From the environmental samples, bacterial isolation was made from three samples, and two could only be identified up to the genus level ( species) while the remaining isolate was identified as (99.22% identity). The study revealed the absence of bovine tuberculosis-causing pathogens in red meat abattoirs of the Gauteng province. Although non-tuberculous have been implicated as potentially causing tuberculosis-like diseases in livestock, their occurrence in the current study was found to be low, but the potential to cause disease cannot be ignored.
PubMed: 38523690
DOI: 10.1155/2024/4636652 -
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 -
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 -
Antonie Van Leeuwenhoek Jan 2024During the course of development plants form tight interactions with microorganisms inhabiting their root zone. In turn, rhizosphere bacteria, in particular members of...
During the course of development plants form tight interactions with microorganisms inhabiting their root zone. In turn, rhizosphere bacteria, in particular members of the phylum Actinomycetota, positively influence the host plant by increasing access to essential nutrients and controlling the pathogenic microorganism's population. Herein, we report the characterisation of the rhizosphere associated actinobacteria community of Phyllostachys viridiglaucescens growing in the Nikitsky Botanical Garden (Crimean Peninsula, Ukraine). The overall composition of the bacterial community was elucidated by 16S rRNA gene amplicon sequencing followed by isolation of culturable microorganisms with the focus on actinomycetes. The metagenomic approach revealed that the representatives of phylum Actinomycetota (57.1%), Pseudomonadota (20.0%), and Acidobacteriota (12.2%) were dominating in the studied microbiome with Ilumatobacter (phylum Actinomycetota) (13.1%) being the dominant genus. Furthermore, a total of 159 actinomycete isolates, belonging to eight genera of Streptomyces, Micromonospora, Nonomuraea, Arthrobacter, Actinomadura, Kribbella, Cellulosimicrobium, and Mumia, were recovered from P. viridiglaucescens rhizosphere. The isolated species were tested for antimicrobial activity. 64% of isolates were active against at least one bacterial test-culture and 7.5% against fungal test culture. In overall, the rhizosphere bacterial communities act as a great source of actinobacterial diversity with the high potential for production of new bioactive compounds.
Topics: Actinobacteria; Actinomyces; Rhizosphere; RNA, Ribosomal, 16S; Actinomycetales; Streptomyces; Poaceae; Soil Microbiology
PubMed: 38170239
DOI: 10.1007/s10482-023-01906-0 -
Frontiers in Microbiology 2023Diels et Gilg, commonly known as Sanyeqing (SYQ), is an important traditional Chinese medicine. The content of bioactive constituents varies in different cultivars of...
Diels et Gilg, commonly known as Sanyeqing (SYQ), is an important traditional Chinese medicine. The content of bioactive constituents varies in different cultivars of SYQ. In the plant growth related researches, rhizosphere microbiome has gained significant attention. However, the role of bacterial communities in the accumulation of metabolites in plants have not been investigated. Herein, the composition of bacterial communities in the rhizosphere soils and the metabolites profile of different SYQ cultivars' roots were analyzed. It was found that the composition of microbial communities varied in the rhizosphere soils of different SYQ cultivars. The high abundance of , and other bacteria was found to be associated with the metabolites profile of SYQ roots. The findings suggest that the upregulation of rutin and hesperetin may contribute to the high bioactive constituent in SYQ roots. These results provide better understanding of the metabolite accumulation pattern in SYQ, and also provide a solution for enhancing the quality of SYQ by application of suitable microbial consortia.
PubMed: 38163074
DOI: 10.3389/fmicb.2023.1292896 -
Frontiers in Plant Science 2023() is an economically important forest tree species, often cultivated in continuous monoculture as a coastal protection forest. Continuous planting has gradually...
Metagenomics-based exploration of key soil microorganisms contributing to continuously planted growth inhibition and their interactions with soil nutrient transformation.
() is an economically important forest tree species, often cultivated in continuous monoculture as a coastal protection forest. Continuous planting has gradually affected growth and severely restricted the sustainable development of the industry. In this study, we analyzed the effects of continuous planting on growth and explored the rhizosphere soil microecological mechanism from a metagenomic perspective. The results showed that continuous planting resulted in dwarfing, shorter root length, and reduced seedling root system. Metagenomics analysis showed that 10 key characteristic microorganisms, mainly , , and , were responsible for continuously planted trees. Quantitative analysis showed that the number of microorganisms in these three genera decreased significantly with the increase of continuous planting. Gene function analysis showed that continuous planting led to the weakening of the environmental information processing-signal transduction ability of soil characteristic microorganisms, and the decrease of trees against stress. Reduced capacity for metabolism, genetic information processing-replication and repair resulted in reduced microbial propagation and reduced microbial quantity in the rhizosphere soil of trees. Secondly, amino acid metabolism, carbohydrate metabolism, glycan biosynthesis and metabolism, lipid metabolism, metabolism of cofactors and vitamins were all significantly reduced, resulting in a decrease in the ability of the soil to synthesize and metabolize carbon and nitrogen. These reduced capacities further led to reduced soil microbial quantity, microbial carbon and nitrogen, microbial respiration intensity, reduced soil enzyme nutrient cycling and resistance-related enzyme activities, a significant reduction in available nutrient content of rhizosphere soils, a reduction in the ion exchange capacity, and an impediment to growth. This study provides an important basis for the management of continuously planted plantations.
PubMed: 38126014
DOI: 10.3389/fpls.2023.1324184