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Scientific Reports Feb 2024Mining has led to severe environmental pollution in countries with exhaustive mining production and inadequate industrial waste regulation. Microorganisms in...
Mining has led to severe environmental pollution in countries with exhaustive mining production and inadequate industrial waste regulation. Microorganisms in contaminated sites, like mine tailings, have adapted to high concentrations of heavy metals, developing the capacity of reducing or removing them from these environments. Therefore, it is essential to thoroughly characterize bacteria present in these sites to find different ways of bioremediation. In this regard, in this study, an enrichment and isolation procedure were performed to isolate bacteria with lower nutritional requirements and high tolerance to Cu(II) and Fe(II) from two Sonoran River basin mining tails. Two Staphylococcus species and a Microbacterium ginsengisoli strain were isolated and identified from the San Felipe de Jesús mining tail. Also, three strains were isolated from the Nacozari de García mining tail: Burkholderia cenocepacia, Sphingomonas sp. and Staphylococcus warneri. Significant microbiological differences were found between the two sites. All these species exhibited tolerance up to 300 mg/L for Cu (II)-Fe (II) solutions, indicating their capacity to grow in these conditions. Moreover, a consortium of isolated bacteria was immobilized in two different biocomposites and the biocomposite with larger pore size achieved greater bacterial immobilization showcasing the potential of these bacteria in biotechnological applications.
Topics: Metals, Heavy; Industrial Waste; Mining; Biodegradation, Environmental; Bacteria; Soil Pollutants
PubMed: 38351239
DOI: 10.1038/s41598-024-54090-0 -
BMC Microbiology Jul 2023Podoconiosis, a non-infectious disease originating from long-term exposure of bare feet to irritant red clay soil is a lifelong, disabling disease with no specific...
BACKGROUND
Podoconiosis, a non-infectious disease originating from long-term exposure of bare feet to irritant red clay soil is a lifelong, disabling disease with no specific diagnostic tool, classified into 5 stages based on the severity of leg swelling (lymphoedema). Secondary bacterial infections have been suggested to cause acute dermatolymphangioadenitis (ADLA) attacks and drive disease progression. Although the North West Region of Cameroon has a proven history of podoconiosis endemicity, the bacterial composition of lymphoedema due to this condition has not been studied. Thus, this study investigated the leg bacterial diversity of patients who suffered from the lymphoedema and their susceptibility pattern to selected antibiotics.
METHODS
A cross-sectional study was carried out in which podoconiosis affected and non-lymphoedema individuals living in the same community were purposively selected. Samples were collected by swabbing the skin between the toes and around the anklebone, then cultured and sub-cultured on nutrient agar to obtain pure isolates. The cultured isolates were then morphologically and biochemically classified using microscopy and analytic profile index test kits, respectively. The disk diffusion technique was used to determine antibiotic susceptibility.
RESULTS
Thirty-three participants were recruited, and 249 bacterial isolates were characterized into 29 genera, 60 species; with 30 (50%) being gram positive rods, 19 (31.7%) gram positive cocci, and 11 (18.3%) gram negative rods. Thirteen gram positive rods, fifteen gram positive cocci, and eight gram negative rods of bacterial species were found only in podoconiosis individuals among which Cellulomonas spp / Microbacterium spp. (2.8%), Staphylococcus lentus (3.3%), and Burkholderia cepacia (4.0%) dominated. 90% (90%) of the bacterial isolates were sensitive to doxycycline, whereas ampicillin had a high level of intermediate resistance, and penicillin G had the greatest resistant profile.
CONCLUSION
Our findings show that 94 (37.8%) out of 249 described bacterial isolates were exclusively found in the legs of podoconiosis individuals, and their susceptibility pattern to antibiotics was similar to that of others.
Topics: Humans; Elephantiasis; Cameroon; Cross-Sectional Studies; Lymphedema; Anti-Bacterial Agents; Gram-Negative Bacteria; Microbial Sensitivity Tests
PubMed: 37460950
DOI: 10.1186/s12866-023-02923-9 -
Frontiers in Plant Science 2024The strains of the genus , with more than 150 species, inhabit diverse environments; plant-associated bacteria reveal their plant growth-promoting activities due to a...
The strains of the genus , with more than 150 species, inhabit diverse environments; plant-associated bacteria reveal their plant growth-promoting activities due to a number of beneficial characteristics. Through the performance of diverse techniques and methods, including isolation of a novel strain from the aerial roots of leafless epiphytic orchid, Seidenf., its morphological and biochemical characterization, chemotaxonomy, phylogenetic and genome analysis, as well as bioassays and estimation of its auxin production capacity, a novel strain of ET2 is described. Despite that it shared 16S rRNA gene sequence similarity of 99.79% with JXJ CY 27-2, so they formed a monophyletic group on phylogenetic trees, the two strains showed clear divergence of their genome sequences. The average nucleotide identity (ANI), average amino acid identity (AAI) and digital DNA-DNA hybridization (dDDH) values of ET2 differed greatly from phylogenetically close JXJ CY 27-2. Based on the differences being below the threshold for species similarity, together with the unique chemotaxonomic characteristics, strain ET2 represents a novel species of the genus . Several genes, putatively involved in auxin biosynthesis were predicted. This strain revealed obvious plant growth-promoting activities, including diazotrophy and biosynthesis of tryptophan-dependent auxins (indole-3-acetic and indole-3-pyruvic acids). Microbial auxins directly stimulated the rhizogenesis, so that the ET2-inoculated seeds of wheat, cucumber and garden cress showed evident promotion in their growth and development, both under optimal and under cold stress conditions. Based on phenotypic, chemotypic and genotypic evidences, the strain ET2 belongs to the genus , order Micrococcales, class Actinomycetes, and it represents a novel species, for which the name sp. nov. is proposed, with strain ET2 (VKPM Ac-2212, VKM Ас-2998) as the type strain.
PubMed: 38559760
DOI: 10.3389/fpls.2024.1360828 -
Microbiology Resource Announcements Dec 2023Bacteriophages Phonegingi and Dropshot were isolated from soil in North Carolina using the host . Both phages have siphovirus morphologies. Based on gene content...
Bacteriophages Phonegingi and Dropshot were isolated from soil in North Carolina using the host . Both phages have siphovirus morphologies. Based on gene content similarity to one another and to other actinobacteriophages, both phages are assigned to phage cluster GA.
PubMed: 38014965
DOI: 10.1128/MRA.00918-23 -
AMB Express Aug 2023Microorganisms play an important role in the tobacco aging process. Before the aging process, raw tobacco leaves must be threshed and redried. In order to explore the...
Microorganisms play an important role in the tobacco aging process. Before the aging process, raw tobacco leaves must be threshed and redried. In order to explore the differences of microbial community structure of threshed and redried tobacco leaves from different origins at home and abroad, 14 groups of tobacco leaves from 8 different countries were tested by high-throughput DNA sequencing and microbiology analysis. Then, through amplicon sequence variants (ASV) cluster analysis, Venn diagram and species labeling and other microbial diversity analysis, the dominant bacteria and fungi on the surface of threshed and redried tobacco leaves were obtained. The results showed that there were significant differences in the composition of tobacco bacteria and fungi after threshing and redrying from different geographical areas. The relative abundance of Microbacterium and Sphingomonas in domestic tobacco leaves was significantly higher than that of foreign tobacco leaves. The relative abundance of Pseudomonas in foreign tobacco bacterial colonies was significantly higher than that of domestic tobacco leaves. In terms of fungi, the relative abundance of Aspergillus and Alternaria in domestic tobacco leaves was significantly higher than that of foreign tobacco leaves. Septoria, Sampaiozyma, Cladosporium and Phoma account for significantly higher proportions of foreign tobacco leaves. These microorganisms may be indispensable in aging process to form different flavors of tobacco leaves. It provides an important theoretical basis for the further use of microorganisms to promote tobacco leaf aging.
PubMed: 37528261
DOI: 10.1186/s13568-023-01580-5 -
Scientific Reports May 2024Spider silk is a promising material with great potential in biomedical applications due to its incredible mechanical properties and resistance to degradation of...
Spider silk is a promising material with great potential in biomedical applications due to its incredible mechanical properties and resistance to degradation of commercially available bacterial strains. However, little is known about the bacterial communities that may inhabit spider webs and how these microorganisms interact with spider silk. In this study, we exposed two exopolysaccharide-secreting bacteria, isolated from webs of an orb spider, to major ampullate (MA) silk from host spiders. The naturally occurring lipid and glycoprotein surface layers of MA silk were experimentally removed to further probe the interaction between bacteria and silk. Extensibility of major ampullate silk produced by Triconephila clavata that was exposed to either Microbacterium sp. or Novosphigobium sp. was significantly higher than that of silk that was not exposed to bacteria (differed by 58.7%). This strain-enhancing effect was not observed when the lipid and glycoprotein surface layers of MA silks were removed. The presence of exopolysaccharides was detected through NMR from MA silks exposed to these two bacteria but not from those without exposure. Here we report for the first time that exopolysaccharide-secreting bacteria inhabiting spider webs can enhance extensibility of host MA silks and silk surface layers play a vital role in mediating such effects.
Topics: Animals; Spiders; Silk; Bacteria; Polysaccharides, Bacterial
PubMed: 38744937
DOI: 10.1038/s41598-024-61723-x -
Microbiology Resource Announcements Aug 2023A complete genome is presented for Microbacterium proteolyticum ustc, a member of the Gram-positive order of the phylum that is resistant to high concentrations of...
A complete genome is presented for Microbacterium proteolyticum ustc, a member of the Gram-positive order of the phylum that is resistant to high concentrations of heavy metals and participates in metal detoxification. The genome consists of one plasmid and one chromosome.
PubMed: 37395667
DOI: 10.1128/mra.00349-23 -
Microbiology Resource Announcements Dec 2023Bacteriophage Morrigan, which was isolated from soil using NRRL B-24224, is lytic with siphovirus morphology. Morrigan's 40,509-bp genome has a GC content of 62.8% and...
Bacteriophage Morrigan, which was isolated from soil using NRRL B-24224, is lytic with siphovirus morphology. Morrigan's 40,509-bp genome has a GC content of 62.8% and 66 putative protein-coding genes, of which 31 could be assigned putative functions. Based on gene content similarity to actinobacteriophages, Morrigan is assigned to subcluster EA6.
PubMed: 37975671
DOI: 10.1128/MRA.00719-23 -
Frontiers in Microbiology 2023River-lake ecosystems are indispensable hubs for water transfers and flow regulation engineering, which have frequent and complex artificial hydrological regulation...
River-lake ecosystems are indispensable hubs for water transfers and flow regulation engineering, which have frequent and complex artificial hydrological regulation processes, and the water quality is often unstable. Microorganisms usually affect these systems by driving the nutrient cycling process. Thus, understanding the key biochemical rate-limiting steps under highly regulated conditions was critical for the water quality stability of river-lake ecosystems. This study investigated how the key microorganisms and genes involving nitrogen and phosphorus cycling contributed to the stability of water by combining 16S rRNA and metagenomic sequencing using the Dongping river-lake system as the case study. The results showed that nitrogen and phosphorus concentrations were significantly lower in lake zones than in river inflow and outflow zones ( < 0.05). , and were the key microorganisms associated with nitrate and phosphate removal. These microorganisms contributed to key genes that promote denitrification (///) and phosphorus absorption and transport (///). Partial least squares path modeling (PLS-PM) revealed that environmental factors (especially flow velocity and COD concentration) have a significant negative effect on the key microbial abundance ( < 0.001). Our study provides theoretical support for the effective management and protection of water transfer and the regulation function of the river-lake system.
PubMed: 37901815
DOI: 10.3389/fmicb.2023.1258659 -
Tree Physiology Aug 2023Endophytic nitrogen-fixing bacteria have been detected and isolated from the needles of conifer trees growing in North American boreal forests. Because boreal forests...
Endophytic nitrogen-fixing bacteria have been detected and isolated from the needles of conifer trees growing in North American boreal forests. Because boreal forests are nutrient-limited, these bacteria could provide an important source of nitrogen for tree species. This study aimed to determine their presence and activity in a Scandinavian boreal forest, using immunodetection of nitrogenase enzyme subunits and acetylene-reduction assays of native Scots pine (Pinus sylvestris L.) needles. The presence and rate of nitrogen fixation by endophytic bacteria were compared between control plots and fertilized plots in a nitrogen-addition experiment. In contrast to the expectation that nitrogen-fixation rates would decline in fertilized plots, as seen, for instance, with nitrogen-fixing bacteria associated with bryophytes, there was no difference in the presence or activity of nitrogen-fixing bacteria between the two treatments. The extrapolated calculated rate of nitrogen fixation relevant for the forest stand was 20 g N ha-1 year-1, which is rather low compared with Scots pine annual nitrogen use but could be important for the nitrogen-poor forest in the long term. In addition, of 13 colonies of potential nitrogen-fixing bacteria isolated from the needles on nitrogen-free media, 10 showed in vitro nitrogen fixation. In summary, 16S rRNA sequencing identified the species as belonging to the genera Bacillus, Variovorax, Novosphingobium, Sphingomonas, Microbacterium and Priestia, which was confirmed by Illumina whole-genome sequencing. Our results confirm the presence of endophytic nitrogen-fixing bacteria in Scots pine needles and suggest that they could be important for the long-term nitrogen budget of the Scandinavian boreal forest.
Topics: Nitrogen-Fixing Bacteria; Taiga; Pinus sylvestris; RNA, Ribosomal, 16S; Acetylene; Nitrogen
PubMed: 37073466
DOI: 10.1093/treephys/tpad048