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Bioengineered Dec 2021The ecological restoration of coal gangue can be achieved by planting (pigeon pea) because of its developed root system. The close relationships soil microorganisms...
The ecological restoration of coal gangue can be achieved by planting (pigeon pea) because of its developed root system. The close relationships soil microorganisms have with plants are crucial for improving soil composition; the soil composition affects nutrient absorption. The microbial composition and function of soil planted with in reclaimed land were compared with soil that was not planted with (the control). Results showed that the dominant microflora in the soil significantly changed after planting . Before planting, the dominant microflora included members of the phyla Sulfobacteria and Acidobacteria. After planting, the dominant microflora contained bacteria from phyla and classes that included , and . Additionally, there were significant differences in the bacterial composition of each layer in soils planted with . Principal component analysis revealed that the interpretation degrees of the results for PC2 and PC3 axes were 10.46% and 3.87%, respectively. The dominant microflora were Vicinamibacterales, , and in the surface soil; and in the deep soil; and and in the mixed-layer soil. Function prediction analysis using the bioinformatics software package PICRUSt revealed that the abundance of operational taxonomic units corresponding to sigma 54-specific transcriptional regulators, serine threonine protein kinase, and histidine kinase increased by 111.2%, 56.8%, and 47.4%, respectively, after planting . This study provides a reference for interactions among microorganisms in reclaimed soils for guiding the development and restoration of waste coal gangue hills.
Topics: Bacteria; Cajanus; DNA, Bacterial; Environmental Restoration and Remediation; High-Throughput Nucleotide Sequencing; Industrial Waste; Principal Component Analysis; Sequence Analysis, DNA; Soil Microbiology
PubMed: 34545768
DOI: 10.1080/21655979.2021.1976043 -
Frontiers in Plant Science 2023Tobacco bacterial wilt (TBW) and black shank (TBS) are responsible for substantial economic losses worldwide; however, microbial interactions and metabolisms in response...
BACKGROUND
Tobacco bacterial wilt (TBW) and black shank (TBS) are responsible for substantial economic losses worldwide; however, microbial interactions and metabolisms in response to TBW and TBS pathogens in the tobacco rhizosphere remain unclear.
METHODS
We explored and compared the response of rhizosphere microbial communities to these two plant diseases with the incidences in moderate and heavy degrees by sequencing of 16S rRNA gene amplicons and bioinformatics analysis.
RESULTS AND DISCUSSIONS
We found that the structure of rhizosphere soil bacterial communities was significantly ( < 0.05) changed from the incidences of TBW and TBS, which also led to decreased Shannon diversity and Pielou evenness. Compared with the healthy group (CK), the OTUs with significantly ( < 0.05) decreased relative abundances were mostly affiliated with Actinobacteria (e.g., and ) in the diseased groups, and the OTUs with significantly ( < 0.05) increased relative abundances were mainly identified as Proteobacteria and Acidobacteria. Also, molecular ecological network analysis showed that the nodes (<467) and links (<641) were decreased in the diseased groups compared with the control group (572; 1056), suggesting that both TBW and TBS weakened bacterial interactions. In addition, the predictive functional analysis indicated that the relative abundance of genes related to the biosynthesis of antibiotics (e.g., ansamycins and streptomycin) was significantly ( < 0.05) decreased due to incidences of TBW and TBS, and antimicrobial tests showed that some Actinobacteria strains (e.g., ) and their secreted antibiotics (e.g., streptomycin) could effectively inhibit the growth of these two pathogens.
PubMed: 37409299
DOI: 10.3389/fpls.2023.1200136 -
3 Biotech Jan 2022Gut symbiotic bacteria provide protection and nutrition to the host insect. A high reproductive rate and dispersal ability of the rugose spiralling whitefly help this...
UNLABELLED
Gut symbiotic bacteria provide protection and nutrition to the host insect. A high reproductive rate and dispersal ability of the rugose spiralling whitefly help this polyphagous species to develop and thrive on many horticultural crops. In this study, we isolated the cultivable gut bacteria associated with rugose spiralling whitefly and demonstrated their role in the host insect. We also studied the influence of antibiotics on the rugose spiralling whitefly oviposition. A total of 70 gut bacteria were isolated from the second nymphal stage of rugose spiralling whitefly reared on coconut, banana, and sapota using seven growth media. From the 70 isolates, chitinase, siderophore (51), protease (44), and Glutathione-S-Transferase producers (16) were recorded. The activities of chitinase, siderophore, protease, and Glutathione-S-Transferase in the gut bacterial isolates of rugose spiralling whitefly ranged from 0.07 to 3.96 µmol min mL, 10.01 to 76.93%, 2.10 to 83.40%, and 5.21 to 24.48 nmol min mL μg protein, respectively. The16S rRNA gene sequence analysis revealed that bacterial genera associated with the gut of rugose spiralling whitefly included , , , , , and Based on the susceptibility of the gut bacteria to antibiotics, 11antibiotic treatments were administered to the host plant leaves infested with the nymphal stages. The antibiotics were evaluated for their effect on rugose spiralling whitefly oviposition. Among the antibiotic treatments, carbenicillin (100 µg mL) + ciprofloxacin (5 µg mL) significantly reduced the oviposition (13 eggs spiral) and egg hatchability (61.54%) of rugose spiralling whitefly. Disruption of chitinase, siderophore, protease, and detoxification enzyme producers and elimination of these symbionts through antibiotics altered the host insect physiology and indirectly affected whitefly oviposition. In conclusion, gut bacteria-based management strategies might be used as insecticides for the effective control of whiteflies.
SUPPLEMENTARY INFORMATION
The online version contains supplementary material available at 10.1007/s13205-021-03081-3.
PubMed: 34966637
DOI: 10.1007/s13205-021-03081-3 -
International Journal of Microbiology 2020This study isolated and identified endophytic bacteria from the leaves of and investigated the potential of the bacterial endophyte extracts as antibacterial and...
This study isolated and identified endophytic bacteria from the leaves of and investigated the potential of the bacterial endophyte extracts as antibacterial and anticancer agents and their subsequent secondary metabolites. Ethyl acetate extracts from the endophytes and the leaves (methanol: dichloromethane (1 : 1)) were used for antibacterial activity against selected pathogenic bacterial strains by using the broth microdilution method. The anticancer activity against the U87MG glioblastoma and A549 lung carcinoma cells was determined by the MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxy-phenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay. Bacterial endophytes that were successfully isolated from leaves include , , sp., , , , , , and . exhibited broad antibacterial activity against both Gram-negative and Gram-positive pathogenic bacteria while displayed the least MIC of 0.0625 mg/mL. crude extracts were the only sample that showed notable cell reduction of 50% against A549 lung carcinoma cells at a concentration of 100 g/mL. Metabolite profiling of , , and crude extracts revealed the presence of known antibacterial and/or anticancer agents such as lycorine (1), angustine (2), crinamidine (3), vasicinol (4), and powelline. It can be concluded that the crude bacterial endophyte extracts obtained from leaves can biosynthesize bioactive compounds and can be bioprospected for medical application into antibacterial and anticancer agents.
PubMed: 33488726
DOI: 10.1155/2020/8839490 -
Iranian Journal of Biotechnology Apr 2022Glycinebetaine (GB) accumulation in many halophytic plants, animals, and microorganisms confers abiotic stress tolerance to salinity, drought, and extreme temperatures....
BACKGROUND
Glycinebetaine (GB) accumulation in many halophytic plants, animals, and microorganisms confers abiotic stress tolerance to salinity, drought, and extreme temperatures. Although there are a few genetic and biochemical pathways to synthesize GB, but isolation of a single gene () from spp. have opened a new hatch to engineer the susceptible plants.
OBJECTIVES
The effects of overexpressed gene, through multiple copy insertion and GB accumulation on salinity tolerance in rice were studied.
MATERIALS AND METHODS
Seed-derived embryogenic calli of 'Tarom Molaie' cultivar were targeted with two plasmids pChlCOD and pCytCOD both harboring the gene using the biolistic mediated transformation. The regenerated T plants were screened by PCR analysis. A line containing three copies of gene and harboring pChlCOD and pCytCOD was identified by Southern blot analysis. The expression of gene in this transgenic line was then confirmed by RT-PCR. The Mendelian segregation pattern of the inserted sequences was accomplished by the progeny test using PCR. The effects of overexpression of on salinity tolerance were evaluated at germination and seedling stage using T-pChl transgenic line and control seeds in the presence of 0, 100, 200, and 300 mM NaCl. Finally, leaf growth dynamics of T-pChlCOD transgenic line and control line under hydroponic conditions in the presence of 0, 40, 80, and 120 mM NaCl were assessed.
RESULTS
The seed germination experiment results showed that the transformed seeds had a higher germination rate than the controls under all salinity treatments. But also, the leaf growth dynamics showed that the control plants had a more favorable leaf growth dynamic in all of the treatments. Although, the transgenic lines (T, T and T) exhibited lower performance than the wild type, the transgenic line varied for GB and choline contents and increasing gene copy number led to increased GB content.
CONCLUSION
In a salinity sensitive crop such as rice, GB may not significantly contribute to the plant protection against salt stress. Also, insufficiency of choline resources as GB precursor might have affected the overall growth ability of the transgenic line and resulted in decreased leaf growth dynamics.
PubMed: 36337062
DOI: 10.30498/ijb.2022.245350.2850 -
Journal of Applied Glycoscience 2023Dextran α-1,2-debranching enzyme (DDE) releases glucose with hydrolyzing α-(1→2)-glucosidic linkages in α-glucans, which are made up of dextran with...
Dextran α-1,2-debranching enzyme (DDE) releases glucose with hydrolyzing α-(1→2)-glucosidic linkages in α-glucans, which are made up of dextran with α-(1→2)-branches and are generated by bacteria. DDE was isolated from (formerly known as sp. M-73) 40 years ago, although the amino acid sequence of the enzyme has not been determined. Herein, we found a gene for this enzyme based on the partial amino acid sequences from native DDE and characterized the recombinant enzyme. DDE had a signal peptide, a glycoside hydrolase family 65 domain, a carbohydrate-binding module family 35 domain, a domain (D-domain) similar to the C-terminal domain of glucodextranase, and a transmembrane region at the C-terminus. Recombinant DDE released glucose from α-(1→2)-branched α-glucans produced by strains B-1299, S-32, and S-64 and showed weak hydrolytic activity with kojibiose and kojitriose. No activity was detected for commercial dextran and B-1355 α-glucan, which do not contain α-(1→2)-linkages. The removal of the D-domain decreased the affinity for α-(1→2)-branched α-glucans but not for kojioligosaccharides, suggesting that D-domain plays a role in α-glucan binding. Genes for putative dextranases, oligo-1,6-glucosidase, sugar-binding protein, and permease were present in the vicinity of the DDE gene, and as a result these gene products may be necessary for the use of α-(1→2)-branched glucans. Our findings shed new light on how actinobacteria utilize polysaccharides produced by lactic acid bacteria.
PubMed: 37033117
DOI: 10.5458/jag.jag.JAG-2022_0013 -
Molecules (Basel, Switzerland) Nov 2022Identification of pesticide impact on the soil microbiome is of the utmost significance today. Diagnosing the response of bacteria to tebuconazole, used for plant...
Identification of pesticide impact on the soil microbiome is of the utmost significance today. Diagnosing the response of bacteria to tebuconazole, used for plant protection, may help isolate the most active bacteria applicable in the bioaugmentation of soils contaminated with this preparation. Bearing in mind the above, a study was undertaken to test the effect of tebuconazole on the diversity of bacteria at all taxonomic levels and on the activity of soil enzymes. It was conducted by means of standard and metagenomic methods. Its results showed that tebuconazole applied in doses falling within the ranges of good agricultural practice did not significantly disturb the biological homeostasis of soil and did not diminish its fertility. Tebuconazole was found to stimulate the proliferation of organotrophic bacteria and fungi, and also the activities of soil enzymes responsible for phosphorus, sulfur, and carbon metabolism. It did not impair the activity of urease responsible for urea hydrolysis, or cause any significant changes in the structure of bacterial communities. All analyzed soil samples were mainly populated by bacteria from the phylum , , , , , , and . Bacteria from the genera , , and predominated in the soils contaminated with tebuconazole, whereas these from the genus were inactivated by this preparation.
Topics: Soil; Soil Microbiology; Microbiota; Triazoles; Bacteria; RNA, Ribosomal, 16S
PubMed: 36364328
DOI: 10.3390/molecules27217501 -
3 Biotech Sep 2021Choline oxidase catalyzes the oxidation of choline to glycine betaine via betaine aldehyde in glycine betaine biosynthesis and betaine acts as an osmolyte. Choline...
UNLABELLED
Choline oxidase catalyzes the oxidation of choline to glycine betaine via betaine aldehyde in glycine betaine biosynthesis and betaine acts as an osmolyte. Choline oxidase has attracted a great deal of attention because of its wide application in clinical and its potential use in enzymatic betaine production. Therefore, the development of efficient methods for overexpression of choline oxidase will be very valuable. In the present study, the choline oxidase gene was amplified from a newly isolated Gram-positive soil strain and was cloned into a pET expression vector. Furthermore, the culture conditions were optimized for overexpression of cloned choline oxidase gene in different hosts for periplasmic expression of the enzyme. Expression host system yielded more cell-free protein and 20 fold higher active enzyme compared to any other reported studies. Terrific Broth media were found to be yielding the highest cell biomass, by applying the optimized culture conditions and purification strategy 20,902 U of choline oxidase was produced with a specific activity of 95 U/mg. The optimum pH and temperature for the enzyme activity were found to be 7 and 37 °C, respectively. Finally, we have demonstrated efficient bioconversion of betaine using overexpressed and purified choline oxidase enzyme. The enzymatically produced betaine was estimated by the formation of betaine reineckate and we were able to produce 0.83 molar of betaine from one molar of choline chloride.
SUPPLEMENTARY INFORMATION
The online version contains supplementary material available at 10.1007/s13205-021-02960-z.
PubMed: 34471592
DOI: 10.1007/s13205-021-02960-z -
Microbiology Spectrum Jun 2022Deciphering distribution patterns of phosphate-solubilizing bacteria (PSB) and phosphorus-cycling-related genes in soils is important to evaluate phosphorus (P)...
Deciphering distribution patterns of phosphate-solubilizing bacteria (PSB) and phosphorus-cycling-related genes in soils is important to evaluate phosphorus (P) transformation. However, the linkage between PSB number and P-cycling-related gene abundance in soils, especially soil aggregates, remains largely unknown. Here, we estimated the numbers of PSB and abundances of P-cycling-related genes (i.e., and ) in soil aggregates under different fertilization regimes as well as P-solubilizing performance and plant-growth-promoting ability of PSB. We found that tricalcium phosphate-solubilizing bacteria, phytate-degrading bacteria, and and abundances were more abundant in silt plus clay (silt+clay; <53 μm) than in macroaggregate (250 to 2000 μm) and microaggregate (53 to 250 μm). Fertilization treatment and aggregate fractionation showed distinct effects on PSB number and P-cycling-related gene abundance. We found significantly negative correlation between gene abundance and tricalcium phosphate-solubilizing bacterial number (Col-CaP) and dramatically positive correlation between gene abundance and phytate-degrading bacterial number (Col-Phy). P fractions were responsible for PSB number and P-cycling-related gene abundance. The isolated Pseudomonas sp. strain PSB-2 and sp. strain PSB-5 exhibited good performances for solubilizing tricalcium phosphate. The inoculation of Pseudomonas sp. PSB-2 could significantly enhance plant fresh weight, plant dry weight, and plant height. Our results emphasized distinct distribution characteristics of PSB and P-cycling-related genes in soil aggregates and deciphered a close linkage between PSB number and P-cycling-related gene abundance. Our findings might guide the isolation of PSB from agricultural soils and provide a candidate plant-growth-promoting bacterium for agro-ecosystems. Phosphate-solubilizing bacteria are responsible for inorganic P solubilization and organic P mineralization. Elucidating the linkage between phosphate-solubilizing bacterial number and P-cycling-related gene abundance is important to isolate plant-growth-promoting bacteria for agro-ecosystems. Our findings reveal differentiating strategies of phosphate-solubilizing bacteria in soil aggregates, and the deciphered P fractions show strong effects on distribution patterns of phosphate-solubilizing bacteria and P-cycling-related genes. Additionally, we isolated phosphate-solubilizing bacteria with good plant-growth-promoting ability. This study enriches our knowledge of P cycling in soil aggregates and might guide the production and management of farmland.
Topics: Bacteria; Clay; Ecosystem; Phosphates; Phosphorus; Phytic Acid; Pseudomonas; Soil; Soil Microbiology
PubMed: 35536021
DOI: 10.1128/spectrum.00290-22 -
PloS One 2021Opencast mining removes topsoil and associated bacterial communities that play crucial roles in soil ecosystem functioning. Understanding the community composition and...
Opencast mining removes topsoil and associated bacterial communities that play crucial roles in soil ecosystem functioning. Understanding the community composition and functioning of these organisms may lead to improve mine-rehabilitation practices. We used a culture-dependent method, combined with Illumina sequencing, to compare the taxonomic richness and composition of living bacterial communities in opencast mine substrates and young mine-rehabilitation plots, with those of soil in adjacent remnant forest at a limestone mine in northern Thailand. We further investigated the effects of soil physico-chemical factors and ground-flora cover on the same. Although, loosened subsoil, brought in to initiate rehabilitation, improved water retention and facilitated plant re-establishment, it did not increase the population density of living microbes substantially within 9 months. Planted trees and sparse ground flora in young rehabilitation plots had not ameliorated the micro-habitat enough to change the taxonomic composition of the soil bacteria compared with non-rehabilitated mine sites. Viable microbes were significantly more abundant in forest soil than in mine substrates. The living bacterial community composition differed significantly, between the forest plots and both the mine and rehabilitation plots. Proteobacteria dominated in forest soil, whereas Firmicutes dominated in samples from both mine and rehabilitation plots. Although, several bacterial taxa could survive in the mine substrate, soil ecosystem functions were greatly reduced. Bacteria, capable of chitinolysis, aromatic compound degradation, ammonification and nitrate reduction were all absent or rare in the mine substrate. Functional redundancy of the bacterial communities in both mine substrate and young mine-rehabilitation soil was substantially reduced, compared with that of forest soil. Promoting the recovery of microbial biomass and functional diversity, early during mine rehabilitation, is recommended, to accelerate soil ecosystem restoration and support vegetation recovery. Moreover, if inoculation is included in mine rehabilitation programs, the genera: Bacillus, Streptomyces and Arthrobacter are likely to be of particular interest, since these genera can be cultivated easily and this study showed that they can survive under the extreme conditions that prevail on opencast mines.
Topics: Bacteria; Calcium Carbonate; Microbial Consortia; Mining; Soil; Soil Microbiology; Trees
PubMed: 33831034
DOI: 10.1371/journal.pone.0248806