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Zoological Studies 2021Bacteria are known to have explicit roles within the microbiomes of host tissues, therefore examining these communities may prove useful in assessing host health and...
Bacteria are known to have explicit roles within the microbiomes of host tissues, therefore examining these communities may prove useful in assessing host health and responses to environmental change. The present study contributes to the emerging, yet understudied, field of microbiome research in elasmobranchs. We provide a screening of the culturable bacteria communities found on multiple tissue sites on the body surface of blacktip (), bull (), and tiger () sharks near Miami, Florida. Tissue sites include mouth, gills, skin, and any visible wounds. The study adds to our understanding of the diversity of bacteria present on sharks in comparison to their natural environment. We also compare bacterial groups found within wounds in shark skin to healthy tissue sites on the same individual. Results indicate that wounds on an individual may allow for opportunistic bacteria to invade or overgrow where they would not normally be found, which may have potential health consequences for sharks that become wounded due to fishing practices. Identified bacteria belonged to the , , and phyla, known to be prominent bacterial groups associated with marine organisms. Results indicate shark species-specific differences in bacterial communities, including the presence of bacteria belonging to exclusively on the skin of tiger sharks. To our knowledge, this is the first report of this family in any elasmobranch. While most tissue sites displayed commensal bacteria identified in similar studies, known pathogens belonging to and were identified in the wounds of blacktip and bull sharks. Some bacteria may be normal residents, but the loss of protective dermal denticles due to a wound may allow colonization by pathogens. Continued research is needed to explore microbial communities associated with sharks and their influence on host health.
PubMed: 35774257
DOI: 10.6620/ZS.2021.60-69 -
Scientific Reports Oct 2019We demonstrate for the first time that the morphology and nanomechanical properties of calcium carbonate (CaCO) can be tailored by modulating the precipitation kinetics...
We demonstrate for the first time that the morphology and nanomechanical properties of calcium carbonate (CaCO) can be tailored by modulating the precipitation kinetics of ureolytic microorganisms through genetic engineering. Many engineering applications employ microorganisms to produce CaCO. However, control over bacterial calcite morphology and material properties has not been demonstrated. We hypothesized that microorganisms genetically engineered for low urease activity would achieve larger calcite crystals with higher moduli. We compared precipitation kinetics, morphology, and nanomechanical properties for biogenic CaCO produced by two Escherichia coli (E. coli) strains that were engineered to display either high or low urease activity and the native producer Sporosarcina pasteurii. While all three microorganisms produced calcite, lower urease activity was associated with both slower initial calcium depletion rate and increased average calcite crystal size. Both calcite crystal size and nanoindentation moduli were also significantly higher for the low-urease activity E. coli compared with the high-urease activity E. coli. The relative resistance to inelastic deformation, measured via the ratio of nanoindentation hardness to modulus, was similar across microorganisms. These findings may enable design of novel advanced engineering materials where modulus is tailored to the application while resistance to irreversible deformation is not compromised.
Topics: Calcium Carbonate; Chemical Precipitation; Crystallization; Escherichia coli; Kinetics; Metabolic Engineering; Microscopy, Electron, Scanning; Organisms, Genetically Modified; Sporosarcina; Urease; X-Ray Diffraction
PubMed: 31604977
DOI: 10.1038/s41598-019-51133-9 -
Scientific Reports Jan 2021Human activities interfere with wild animals and lead to the loss of many animal populations. Therefore, efforts have been made to understand how wildlife can rebound...
Human activities interfere with wild animals and lead to the loss of many animal populations. Therefore, efforts have been made to understand how wildlife can rebound from anthropogenic disturbances. An essential mechanism to adapt to environmental and social changes is the fluctuations in the host gut microbiome. Here we give a comprehensive description of anthropogenically induced microbiome alterations in Asian elephants (n = 30). We detected gut microbial changes due to overseas translocation, captivity and deworming. We found that microbes belonging to Planococcaceae had the highest contribution in the microbiome alterations after translocation, while Clostridiaceae, Spirochaetaceae and Bacteroidia were the most affected after captivity. However, deworming significantly changed the abundance of Flavobacteriaceae, Sphingobacteriaceae, Xanthomonadaceae, Weeksellaceae and Burkholderiaceae. These findings may provide fundamental ideas to help guide the preservation tactics and probiotic replacement therapies of a dysbiosed gut microbiome in Asian elephants. More generally, these results show the severity of anthropogenic activities at the level of gut microbiome, altering the adaptation processes to new environments and the subsequent capability to maintain normal physiological processes in animals.
Topics: Adaptation, Physiological; Animals; Asia; Dysbiosis; Ecosystem; Elephants; Environmental Monitoring; Female; Gastrointestinal Microbiome; Male
PubMed: 33436882
DOI: 10.1038/s41598-020-80537-1 -
Animals : An Open Access Journal From... Oct 2022Intestinal microbiota play an important role in the survival of the host. However, no study to date has elucidated the adjustment of intestinal microbiota of the host...
Intestinal microbiota play an important role in the survival of the host. However, no study to date has elucidated the adjustment of intestinal microbiota of the host during rewilding. Thus, this study aims to describe the intestinal bacterial community of reintroduced Przewalski’s horse (RPH) after being released into their original habitat for approximately 20 years in comparison with that of captive Przewalski’s horse (CPH), sympatric domestic horse (DH) and Mongolian wild ass (MWA) by sequencing the 16S rRNA gene. The results showed that the prevalent bacterial communities were different among CPHs, RPHs, DHs and MWAs at the family level. NMDS and ANOSIM analysis showed that the pattern of bacterial community composition in captive equines was distinct from that in the wild groups. It is shown that some bacteria had significant differences among different taxa (p < 0.001), such as Firmicutes, Bacteroidetes, Armatimonadetes, Clostrida, Bacteroidia, Clostridiales, Bacteroidales, Rikenellaceae and Bacteroidales_UCG-001. These bacteria were associated with the transition from in captive to in the wild (CPH and RPH), which reflected the change of environmental conditions. Meanwhile, Proteobacteria, Clostridia, Bacilli, Negativicutes, Gammaproteobacteria, Clostridiales, Bacillales, Selenomonadales, Pseudomonadales and Planococcaceae were the changed groups among RPHs, MWAs and DHs, which are related to feeding habits and diseases. Our results clearly showed the differences between intestinal microbiota in reintroduced animals and wild animals and led us to understand the survival state of reintroduced animals in the wild.
PubMed: 36290262
DOI: 10.3390/ani12202874 -
Microbial Cell Factories Jan 2020The ureolytic bacterium Sporosarcina pasteurii is well-known for its capability of microbially induced calcite precipitation (MICP), representing a great potential in...
BACKGROUND
The ureolytic bacterium Sporosarcina pasteurii is well-known for its capability of microbially induced calcite precipitation (MICP), representing a great potential in constructional engineering and material applications. However, the molecular mechanism for its biomineralization remains unresolved, as few studies were carried out.
RESULTS
The addition of urea into the culture medium provided an alkaline environment that is suitable for S. pasteurii. As compared to S. pasteurii cultivated without urea, S. pasteurii grown with urea showed faster growth and urease production, better shape, more negative surface charge and higher biomineralization ability. To survive the unfavorable growth environment due to the absence of urea, S. pasteurii up-regulated the expression of genes involved in urease production, ATPase synthesis and flagella, possibly occupying resources that can be deployed for MICP. As compared to non-mineralizing bacteria, S. pasteurii exhibited more negative cell surface charge for binding calcium ions and more robust cell structure as nucleation sites. During MICP process, the genes for ATPase synthesis in S. pasteurii was up-regulated while genes for urease production were unchanged. Interestingly, genes involved in flagella were down-regulated during MICP, which might lead to poor mobility of S. pasteurii. Meanwhile, genes in fatty acid degradation pathway were inhibited to maintain the intact cell structure found in calcite precipitation. Both weak mobility and intact cell structure are advantageous for S. pasteurii to serve as nucleation sites during MICP.
CONCLUSIONS
Four factors are demonstrated to benefit the super performance of S. pasteurii in MICP. First, the good correlation of biomass growth and urease production of S. pasteurii provides sufficient biomass and urease simultaneously for improved biomineralization. Second, the highly negative cell surface charge of S. pasteurii is good for binding calcium ions. Third, the robust cell structure and fourth, the weak mobility, are key for S. pasteurii to be nucleation sites during MICP.
Topics: ATP Synthetase Complexes; Biomineralization; Calcium Carbonate; Culture Media; Gene Expression Profiling; Genome, Bacterial; Microscopy, Electron, Scanning; Sporosarcina; Urea; Urease
PubMed: 31973723
DOI: 10.1186/s12934-020-1281-z -
MicrobiologyOpen Jun 2020Strain Y74 was an isolate from the sandy soil in the town of Huatugou, Qinghai-Tibet Plateau, China. An analysis of this strain's phenotypic, chemotaxonomic, and genomic...
Strain Y74 was an isolate from the sandy soil in the town of Huatugou, Qinghai-Tibet Plateau, China. An analysis of this strain's phenotypic, chemotaxonomic, and genomic characteristics established the relationship of the isolate with the genus Planococcus. Strain Y74 was able to grow between 4 and 42°C (with an optimum temperature of 28°C) at pH values of 6-8.5 and in 0%-7% (w/v) NaCl. The dominant quinones were MK-8 and MK-7. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, and an unknown phospholipid. The majority of the fatty acid content was anteiso-C (28.8%) followed by C ω7c alcohol (20.9%) and iso-C (13.4%). The 16S rRNA gene sequence similarity analysis demonstrated a stable branch formed by strain Y74 and Planococcus halotolerans SCU63 (99.66%). The digital DNA-DNA hybridization between these two strains was 57.2%. The G + C content in the DNA of Y74 was 44.5 mol%. In addition, the morphological, physiological, and chemotaxonomic pattern clearly differentiated the isolates from their known relatives. In conclusion, the strain Y74 (=JCM 32826 = CICC24461 ) represents a novel member of the genus Planococcus, for which the name Planococcus antioxidans sp. nov. is proposed. Strain Y74 was found to have potent antioxidant activity via its hydrogen peroxide tolerance and its 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity. The DPPH radical-scavenging activity was determined to be 40.2 ± 0.7%. The genomic analysis indicated that six peroxidases genes, one superoxide dismutase gene, and one dprA (DNA-protecting protein) are present in the genome of Y74 .
Topics: Antioxidants; Bacterial Typing Techniques; Base Composition; DNA, Bacterial; Fatty Acids; Genome, Bacterial; Planococcus Bacteria; Sequence Analysis, DNA; Soil Microbiology; Tibet; Whole Genome Sequencing
PubMed: 32162498
DOI: 10.1002/mbo3.1028 -
Scientific Reports Oct 2019Bacteria swim and swarm by rotating the micrometers long, helical filaments of their flagella. They change direction by reversing their flagellar rotation, which...
Bacteria swim and swarm by rotating the micrometers long, helical filaments of their flagella. They change direction by reversing their flagellar rotation, which switches the handedness of the filament's supercoil. So far, all studied functional filaments are composed of a mixture of L- and R-state flagellin monomers. Here we show in a study of the wild type Firmicute Kurthia sp., that curved, functional filaments can adopt a conformation in vivo that is closely related to a uniform, all-L-state. This sheds additional light on transitions of the flagellar supercoil and uniquely reveals the atomic structure of a wild-type flagellar filament in vivo, including six residues showing clearly densities of O-linked glycosylation.
Topics: Anisotropy; Bacterial Proteins; Cryoelectron Microscopy; Firmicutes; Flagella; Flagellin; Fourier Analysis; Glycosylation; Planococcaceae; Software
PubMed: 31628388
DOI: 10.1038/s41598-019-51440-1 -
Journal of Microbiology and... Sep 2021Microbially induced calcium carbonate precipitation (MICP) has recently become an intelligent and environmentally friendly method for repairing cracks in concrete. To...
Microbially induced calcium carbonate precipitation (MICP) has recently become an intelligent and environmentally friendly method for repairing cracks in concrete. To improve on this ability of microbial materials concrete repair, we applied random mutagenesis and optimization of mineralization conditions to improve the quantity and crystal form of microbially precipitated calcium carbonate. ATCC 11859 was used as the starting strain to obtain the mutant with high urease activity by atmospheric and room temperature plasma (ARTP) mutagenesis. Next, we investigated the optimal biomineralization conditions and precipitation crystal form using Plackett-Burman experimental design and response surface methodology (RSM). Biomineralization with 0.73 mol/l calcium chloride, 45 g/l urea, reaction temperature of 45°C, and reaction time of 22 h, significantly increased the amount of precipitated calcium carbonate, which was deposited in the form of calcite crystals. Finally, the repair of concrete using the optimized biomineralization process was evaluated. A comparison of water absorption and adhesion of concrete specimens before and after repairs showed that concrete cracks and surface defects could be efficiently repaired. This study provides a new method to engineer biocementing material for concrete repair.
Topics: Analysis of Variance; Biomineralization; Calcium Carbonate; Calcium Chloride; Construction Materials; Mutagenesis; Mutation; Plasma Gases; Sporosarcina; Temperature; Urea; Urease
PubMed: 34319256
DOI: 10.4014/jmb.2104.04019 -
Microorganisms Dec 2019Antibiotic resistance is a global issue which is magnified by interspecies horizontal gene transfer. Understanding antibiotic resistance in bacteria in a natural setting...
Antibiotic resistance is a global issue which is magnified by interspecies horizontal gene transfer. Understanding antibiotic resistance in bacteria in a natural setting is crucial to check whether they are multidrug resistant (MDR) and possibly avoid outbreaks. In this study, we have isolated several antibiotic-resistant bacteria (ARB) ( = 128) from the mangroves in Kerala, India. ARBs were distributed based on antibiotics ( = 1.6 × 10). The 16S rRNA gene characterization revealed dominance by Bacillaceae (45%), Planococcaceae (22.5%), and Enterobacteriaceae (17.5%). A high proportion of the isolates were MDR (75%) with maximum resistance to methicillin (70%). Four isolates affiliated to plant-growth promoters, probiotics, food, and human pathogens were resistant to all antibiotics indicating the seriousness and prevalence of MDR. A significant correlation (R = 0.66; = 2.5 × 10) was observed between MDR and biofilm formation. Antagonist activity was observed in 62.5% isolates. Gram-positive isolates were more susceptible to antagonism (75.86%) than gram-negative (36.36%) isolates. Antagonism interactions against gram-negative isolates were lower (9.42%) when compared to gram-positive isolates (89.85%). Such strong antagonist activity can be harnessed for inspection of novel antimicrobial mechanisms and drugs. Our study shows that MDR with strong biofilm formation is prevalent in natural habitat and if acquired by deadly pathogens may create havoc in public health.
PubMed: 31835720
DOI: 10.3390/microorganisms7120678 -
International Journal of Systematic and... Mar 2024A novel bacterial strain, APC 4016, was previously isolated from the skin of a snub-nosed spiny eel, , from a depth of 1000 m in the northern Atlantic Ocean. Cells...
A novel bacterial strain, APC 4016, was previously isolated from the skin of a snub-nosed spiny eel, , from a depth of 1000 m in the northern Atlantic Ocean. Cells were aerobic, cocci, motile, Gram-positive to Gram-variable staining, and gave rise to orange-pigmented colonies. Growth occurred at 4-40 °C (optimum, 25-28 °C), pH 5.5-12 (optimum, pH 7-7.5), and 0-12 % (w/v) NaCl (optimum, 1 %). 16S rRNA gene phylogenetic analysis confirmed that strain APC 4016 belonged to the genus and was most closely related to IFO 12536 (98.98 % 16S similarity). However, digital DNA-DNA hybridization and average nucleotide identity values between these two strains were low, at 20.1 and 83.8 %, respectively. Major (>10 %) cellular fatty acids of strain APC 4016 were iso-C, anteiso-C and C-ω-Alc. The predominant respiratory quinones were menaquinones 5, 6, 7 and 8. The major cellular polar lipids were phosphatidylglycerol, diphosphatidylglycerol and phosphatidylethanolamine, and three unknown lipids were also present. The draft genome sequence is 3.6 Mb with a G+C content of 45.25 mol%. This strain was previously shown to have antimicrobial activity and to encode bacteriocin and secondary metabolite biosynthetic gene clusters. Based on the phylogenetic analysis and its distinct phenotypic characteristics, strain APC 4016 is deemed to represent a novel species of the genus , and for which the name sp. nov. is proposed. The type strain of this species is APC 4016 (=DSM 115753=NCIMB 15463).
Topics: Animals; Fatty Acids; Phospholipids; Phylogeny; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Base Composition; Bacterial Typing Techniques; DNA, Bacterial; Planococcus Bacteria; Eels
PubMed: 38512752
DOI: 10.1099/ijsem.0.006298