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PloS One 2022The filling mining method is an effective method for controlling ground stress and preventing surface subsidence in the mining field during exploitation of underground...
The filling mining method is an effective method for controlling ground stress and preventing surface subsidence in the mining field during exploitation of underground resources. Tailings can be utilized as the filling material, so as to realize the reuse of industrial waste. However, utilization of the traditional Portland cement as the cementing material for tailings leads to groundwater pollution. In addition, production of Portland cement results in consumption of a great amount of ore and air pollution. In this paper, a tailings cementation method by using the microbial induced calcite precipitation (MICP) technique with immersion curing is proposed. Tailings are cemented by the MICP technique with aerobic bacteria (Sporosarcina pasteurii) under a soaked curing environment. The variable control method is applied to investigate the factors influencing the cementation effects by the MICP technique with Sporosarcina pasteurii, including the bacterial solution concentration, the cementing solution concentration, the particle size of tailings, and the curing temperature. The results indicate that: when OD600 of the Sporosarcina pasteurii solution is 1.6, the urea concentration in the cementing solution is 0.75 mol/L, the tailings are raw materials without grinding, and the curing temperature is 30°C, the cementation effect is the best. In view of uneven calcification during MICP with Sporosarcina pasteurii, mixed Sporosarcina pasteurii and Castellaniella denitrificans are used for tailings cementation. Higher strength of cemented tailings is achieved. It is proved that the MICP technique with mixed aerobic bacteria and facultative anaerobes is an effective method for tailings cementation.
Topics: Bacteria; Calcium Carbonate; Cementation; Immersion; Sporosarcina
PubMed: 35913918
DOI: 10.1371/journal.pone.0272281 -
BMC Microbiology Oct 2021Extremophiles have attracted much attention in the last few decades, as they possess different properties by producing certain useful metabolites. However, the secondary...
BACKGROUND
Extremophiles have attracted much attention in the last few decades, as they possess different properties by producing certain useful metabolites. However, the secondary metabolism of the extremophiles of Antarctic krill has received little attention.
RESULTS
In this study, a new bacterial strain MSAK28401 from Antarctic krill was isolated and identified. The results of analysis on phenotypic, chemotaxonomic, and genomic characteristics showed that the strain MSAK28401 belongs to the genus Planococcus. Cells of this strain were coccoid (0.89-1.05 μm) and aerobic. The majority of the fatty acid content was C anteiso (37.67 ± 0.90%) followed by C ω7c alcohol (10.37 ± 1.22%) and C iso (9.36 ± 0.71%). The calculated average nucleotide identity and DNA-DNA hybridization values between the strain MSAK28401 and type strains P. citreus DSM 20549 and P. rifietoensis M8 were lower than 91 and 70%, respectively. The strain MSAK28401 (=KCTC 43283 and MCCC 1k05448) represented a new member of the genus Planococcus and was named P. alpniumensis sp. nov. Moreover, genes involved in the degradation of aromatic compounds (e.g., salicylate, gentisate, and quinate) were found in the genome, implying that strain MSAK28401 has an aromatic compound as its potential metabolite. This work will help us understand the genomic characteristics and potential metabolic pathway of Planococcus from Antarctic krill.
CONCLUSIONS
This study reported the genomic information and phenotypic characteristics of the new strain P. alpniumensis MSAK28401 isolated from Antarctic krill, and provided the genome information of Planococcus strains for further studying the function roles in aromatic compound metabolism.
Topics: Animals; Antarctic Regions; Bacterial Proteins; DNA, Bacterial; Euphausiacea; Extremophiles; Fatty Acids; Genome, Bacterial; Nucleic Acid Hybridization; Phenotype; Phylogeny; Planococcus Bacteria; Secondary Metabolism; Sequence Analysis, DNA
PubMed: 34686131
DOI: 10.1186/s12866-021-02347-3 -
Journal of Animal Science and... Jan 2022Previous studies had shown that short-term acute heat stress (HS) affected the host's metabolism and intestinal microbiota independent of feed intake (FI) reduction, and...
Alterations in intestinal microbiota composition coincide with impaired intestinal morphology and dysfunctional ileal immune response in growing-finishing pigs under constant chronic heat stress.
BACKGROUND
Previous studies had shown that short-term acute heat stress (HS) affected the host's metabolism and intestinal microbiota independent of feed intake (FI) reduction, and long-term calorie restriction caused intestinal morphological injuries and gut microbial alterations. However, research on the effects of constant chronic HS on intestinal microbial composition and the roles of FI reduction played in is limited. This study aimed to investigate the effects of 7-day constant chronic HS on the composition of intestinal microbes in growing-finishing pigs, and its relationship with pigs' performance, intestinal morphology, and ileal immune response. Twenty-four growing-finishing pigs (Duroc × Large White × Landrace, 30 ± 1 kg body weight) were randomly assigned to three treatments (n = 8), 1) thermal neutral (TN) conditions (25 ± 1 °C) with ad libitum FI, 2) HS conditions (35 ± 1 °C) with ad libitum FI, 3) pair-fed (PF) with HS under TN conditions to discriminate the confounding effects of dissimilar FI, and the FI was the previous day's average FI of HS. The small intestinal segments (duodenum, jejunum, and ileum) and feces were collected on d 8.
RESULTS
Results indicated that HS drastically declined (P < 0.05) average daily gain (ADG) and average daily feed intake (ADFI) (about 61%) in comparison with TN, and caused hyperpyrexia, meanwhile PF caused hypothermia. Morphological observation by light and electron microscopes showed that both HS and PF treatment decreased (P < 0.05) the villus and microvillus height compared with TN. Additionally, HS increased (P < 0.05) protein expression of heat shock protein 70 in the duodenum, jejunum, and ileum. Furthermore, the expression of tight junction protein zonula occluden-1 (ZO-1) in the duodenum and ileum, and Occludin in the ileum were enhanced (P < 0.05) compared with TN and PF. Moreover, HS significantly enhanced (P < 0.05) the mRNA relative expression of inflammatory cytokines (TLR-2, TLR-4, and tumor necrosis factor-α (TNF-α), IL-6, IL-8, PG1-5, β-defensin 2 (pBD-2)), mucins (mucin-1 and mucin-2) and P65 protein level in the ileal mucosa tissue. Intestinal microbiota analysis by 16S rRNA sequencing showed lower (P < 0.10) α diversity in both HS and PF, and a separated cluster of β diversity among groups. Compared with TN, HS but not PF mainly reduced (FDR < 0.05) Bacteroidetes (phylum), Bacteroidia (class) and elevated the proportions of Proteobacteria (phylum, FDR < 0.05), Bacillales (order, FDR < 0.05), Planococcaceae (family, FDR < 0.05), Kurthia (genus, FDR < 0.05), Streptococcaceae (family, FDR < 0.10) and Streptococcus (genus, FDR < 0.10). Notably, Lactobacillales (order) was decreased (FDR < 0.05) by PF alone. Furthermore, the Spearman correlation analysis indicated that the microbes prevalent in HS were positively (P < 0.05) associated with intestinal morphological injuries indicators and ileal immune response parameters, and the microbes reduced in HS were negatively (P < 0.05) with the performance data.
CONCLUSIONS
Intestinal morphological injuries and ileal immune response caused by constant chronic HS independent of FI showed close connections with alterations in intestinal microbiota in growing-finishing pigs.
PubMed: 34983683
DOI: 10.1186/s40104-021-00651-6 -
Microbial Cell Factories Mar 2022The genus Planococcus is comprised of halophilic bacteria generally reported for the production of carotenoid pigments and biosurfactants. In previous work, we showed...
BACKGROUND
The genus Planococcus is comprised of halophilic bacteria generally reported for the production of carotenoid pigments and biosurfactants. In previous work, we showed that the culturing of the orange-pigmented Planococcus sp. CP5-4 isolate increased the evaporation rate of industrial wastewater brine effluent, which we attributed to the orange pigment. This demonstrated the potential application of this bacterium for industrial brine effluent management in evaporation ponds for inland desalination plants. Here we identified a C-carotenoid biosynthetic gene cluster responsible for pigment biosynthesis in Planococcus sp. CP5-4 through isolation of mutants and genome sequencing. We further compare the core genes of the carotenoid biosynthetic gene clusters identified from different Planococcus species' genomes which grouped into gene cluster families containing BGCs linked to different carotenoid product chemotypes. Lastly, LC-MS analysis of saponified and unsaponified pigment extracts obtained from cultures of Planococcus sp. CP5-4, revealed the structure of the main (predominant) glucosylated C-carotenoid fatty acid ester produced by Planococcus sp. CP5-4.
RESULTS
Genome sequence comparisons of isolated mutant strains of Planococcus sp. CP5-4 showed deletions of 146 Kb and 3 Kb for the non-pigmented and "yellow" mutants respectively. Eight candidate genes, likely responsible for C-carotenoid biosynthesis, were identified on the wild-type genome region corresponding to the deleted segment in the non-pigmented mutant. Six of the eight candidate genes formed a biosynthetic gene cluster. A truncation of crtP was responsible for the "yellow" mutant phenotype. Genome annotation revealed that the genes encoded 4,4'-diapolycopene oxygenase (CrtNb), 4,4'- diapolycopen-4-al dehydrogenase (CrtNc), 4,4'-diapophytoene desaturase (CrtN), 4,4'- diaponeurosporene oxygenase (CrtP), glycerol acyltransferase (Agpat), family 2 glucosyl transferase 2 (Gtf2), phytoene/squalene synthase (CrtM), and cytochrome P450 hydroxylase enzymes. Carotenoid analysis showed that a glucosylated C-carotenoid fatty acid ester, methyl 5-(6-C)-glucosyl-5, 6'-dihydro-apo-4, 4'-lycopenoate was the main carotenoid compound produced by Planococcus sp. CP5-4.
CONCLUSION
We identified and characterized the carotenoid biosynthetic gene cluster and the C-carotenoid compound produced by Planococcus sp. CP5-4. Mass-spectrometry guided analysis of the saponified and unsaponified pigment extracts showed that methyl 5-glucosyl-5, 6-dihydro-apo-4, 4'-lycopenoate esterified to heptadecatrienoic acid (C). Furthermore, through phylogenetic analysis of the core carotenoid BGCs of Planococcus species we show that various C-carotenoid product chemotypes, apart from methyl 5-glucosyl-5, 6-dihydro-apo-4, 4'-lycopenoate and 5-glucosyl-4, 4-diaponeurosporen-4'-ol-4-oic acid, may be produced that could offer opportunities for a variety of applications.
Topics: Carotenoids; Multigene Family; Phylogeny; Planococcus Bacteria; South Africa
PubMed: 35305628
DOI: 10.1186/s12934-022-01752-1 -
PloS One 2023Gram-positive, aerobic, motile, rod-shaped, mesophilic epiphytic bacterium Planomicrobium okeanokoites was isolated from the surface of endemic species Himantothallus...
Gram-positive, aerobic, motile, rod-shaped, mesophilic epiphytic bacterium Planomicrobium okeanokoites was isolated from the surface of endemic species Himantothallus grandifolius in Larsemann Hills, Eastern Antarctica. The diversity of epiphytic bacterial communities living on marine algae remains primarily unexplored; virtually no reports from Antarctic seaweeds. The present study used morpho-molecular approaches for the macroalgae and epiphytic bacterium characterization. Phylogenetic analysis was performed using mitochondrial genome encoded COX1 gene; chloroplast genome encodes rbcL; nuclear genome encoded large subunit ribosomal RNA gene (LSU rRNA) for Himantothallus grandifolius and ribosomal encoded 16S rRNA for Planomicrobium okeanokoites. Morphological and molecular data revealed that the isolate is identified as Himantothallus grandifolius, which belongs to Family Desmarestiaceae of Order Desmarestiales in Class Phaeophyceae showing 99.8% similarity to the sequences of Himantothallus grandifolius, from King George Island, Antarctica (HE866853). The isolated bacterial strain was identified on the basis of chemotaxonomic, morpho-phylogenetic, and biochemical assays. A phylogenetic study based on 16S rRNA gene sequences revealed that the epiphytic bacterial strain SLA-357 was closest related to the Planomicrobium okeanokoites showing 98.7% sequence similarity. The study revealed the first report of this species from the Southern Hemisphere to date. Also, there has been no report regarding the association between the Planomicrobium okeanokoites and Himantothallus grandifolius; however, there are some reports on this bacterium isolated from sediments, soils, and lakes from Northern Hemisphere. This study may open a gateway for further research to know about the mode of interactions and how they affect the physiology and metabolism of each other.
Topics: RNA, Ribosomal, 16S; Phylogeny; Planococcaceae; Phaeophyceae; Bacteria; Seaweed; Antarctic Regions; DNA, Bacterial; Fatty Acids; Sequence Analysis, DNA; Bacterial Typing Techniques
PubMed: 37058520
DOI: 10.1371/journal.pone.0282516 -
Scientific Reports Mar 2021Due to their antimicrobial properties, silver nanoparticles (AgNPs) are used in a wide range of consumer products that includes topical wound dressings, coatings for...
Due to their antimicrobial properties, silver nanoparticles (AgNPs) are used in a wide range of consumer products that includes topical wound dressings, coatings for biomedical devices, and food-packaging to extend the shelf-life. Despite their beneficial antimicrobial effects, developmental exposure to such AgNPs may lead to gut dysbiosis and long-term health consequences in exposed offspring. AgNPs can cross the placenta and blood-brain-barrier to translocate in the brain of offspring. The underlying hypothesis tested in the current study was that developmental exposure of male and female mice to AgNPs disrupts the microbiome-gut-brain axis. To examine for such effects, C57BL6 female mice were exposed orally to AgNPs at a dose of 3 mg/kg BW or vehicle control 2 weeks prior to breeding and throughout gestation. Male and female offspring were tested in various mazes that measure different behavioral domains, and the gut microbial profiles were surveyed from 30 through 120 days of age. Our study results suggest that developmental exposure results in increased likelihood of engaging in repetitive behaviors and reductions in resident microglial cells. Echo-MRI results indicate increased body fat in offspring exposed to AgNPs exhibit. Coprobacillus spp., Mucispirillum spp., and Bifidobacterium spp. were reduced, while Prevotella spp., Bacillus spp., Planococcaceae, Staphylococcus spp., Enterococcus spp., and Ruminococcus spp. were increased in those developmentally exposed to NPs. These bacterial changes were linked to behavioral and metabolic alterations. In conclusion, developmental exposure of AgNPs results in long term gut dysbiosis, body fat increase and neurobehavioral alterations in offspring.
Topics: Animals; Behavior; Dysbiosis; Female; Gastrointestinal Microbiome; Humans; Male; Maze Learning; Mental Status and Dementia Tests; Metagenome; Metagenomics; Metal Nanoparticles; Mice; Models, Animal; Silver
PubMed: 33753813
DOI: 10.1038/s41598-021-85919-7 -
Molecules (Basel, Switzerland) Oct 2021The use of additives has generated significant attention due to their extensive application in the microbially induced calcium carbonate precipitation (MICP) process....
The use of additives has generated significant attention due to their extensive application in the microbially induced calcium carbonate precipitation (MICP) process. This study aims to discuss the effects of Na-montmorillonite (Na-MMT) on CaCO crystallization and sandy soil consolidation through the MICP process. Compared with the traditional MICP method, a larger amount of CaCO precipitate was obtained. Moreover, the reaction of Ca ions was accelerated, and bacteria were absorbed by a small amount of Na-MMT. Meanwhile, an increase in the total cementing solution (TCS) was not conducive to the previous reaction. This problem was solved by conducting the reaction with Na-MMT. The polymorphs and morphologies of the CaCO precipitates were tested by using X-ray diffraction and scanning electron microscopy. Further, when Na-MMT was used, the morphology of CaCO changed from an individual precipitate to agglomerations of the precipitate. Compared to the experiments without Na-MMT in the MICP process, the addition of Na-MMT significantly reduced the hydraulic conductivity (HC) of sandy soil consolidated.
Topics: Bentonite; Biotechnology; Calcium Carbonate; Chemical Precipitation; Crystallization; Microscopy, Electron, Scanning; Sand; Soil; Sporosarcina; X-Ray Diffraction
PubMed: 34684789
DOI: 10.3390/molecules26206211 -
Astrobiology Sep 2018It is well known that dissolved salts can significantly lower the freezing point of water and thus extend habitability to subzero conditions. However, most...
It is well known that dissolved salts can significantly lower the freezing point of water and thus extend habitability to subzero conditions. However, most investigations thus far have focused on sodium chloride as a solute. In this study, we report on the survivability of the bacterial strain Planococcus halocryophilus in sodium, magnesium, and calcium chloride or perchlorate solutions at temperatures ranging from +25°C to -30°C. In addition, we determined the survival rates of P. halocryophilus when subjected to multiple freeze/thaw cycles. We found that cells suspended in chloride-containing samples have markedly increased survival rates compared with those in perchlorate-containing samples. In both cases, the survival rates increase with lower temperatures; however, this effect is more pronounced in chloride-containing samples. Furthermore, we found that higher salt concentrations increase survival rates when cells are subjected to freeze/thaw cycles. Our findings have important implications not only for the habitability of cold environments on Earth but also for extraterrestrial environments such as that of Mars, where cold brines might exist in the subsurface and perhaps even appear temporarily at the surface such as at recurring slope lineae.
Topics: Chlorides; Cold Temperature; Freezing; Microbial Viability; Osmolar Concentration; Perchlorates; Planococcus Bacteria; Salts; Water
PubMed: 29664686
DOI: 10.1089/ast.2017.1805 -
Journal of Applied Microbiology Jun 2015Ureolysis drives microbially induced calcium carbonate precipitation (MICP). MICP models typically employ simplified urea hydrolysis kinetics that do not account for...
AIMS
Ureolysis drives microbially induced calcium carbonate precipitation (MICP). MICP models typically employ simplified urea hydrolysis kinetics that do not account for cell density, pH effect or product inhibition. Here, ureolysis rate studies with whole cells of Sporosarcina pasteurii aimed to determine the relationship between ureolysis rate and concentrations of (i) urea, (ii) cells, (iii) NH4+ and (iv) pH (H(+) activity).
METHODS AND RESULTS
Batch ureolysis rate experiments were performed with suspended cells of S. pasteurii and one parameter was varied in each set of experiments. A Michaelis-Menten model for urea dependence was fitted to the rate data (R(2) = 0·95) using a nonlinear mixed effects statistical model. The resulting half-saturation coefficient, Km , was 305 mmol l(-1) and maximum rate constant, Vmax , was 200 mmol l(-1) h(-1) . However, a first-order model with k1 = 0·35 h(-1) fit the data better (R(2) = 0·99) for urea concentrations up to 330 mmol l(-1) . Cell concentrations in the range tested (1 × 10(7) -2 × 10(8) CFU ml(-1) ) were linearly correlated with ureolysis rate (cell dependent Vmax' = 6·4 × 10(-9) mmol CFU(-1) h(-1) ).
CONCLUSIONS
Neither pH (6-9) nor ammonium concentrations up to 0·19 mol l(-1) had significant effects on the ureolysis rate and are not necessary in kinetic modelling of ureolysis. Thus, we conclude that first-order kinetics with respect to urea and cell concentrations are likely sufficient to describe urea hydrolysis rates at most relevant concentrations.
SIGNIFICANCE AND IMPACT OF THE STUDY
These results can be used in simulations of ureolysis driven processes such as microbially induced mineral precipitation and they verify that under the stated conditions, a simplified first-order rate for ureolysis can be employed. The study shows that the kinetic models developed for enzyme kinetics of urease do not apply to whole cells of S. pasteurii.
Topics: Bacterial Proteins; Calcium Carbonate; Hydrolysis; Kinetics; Sporosarcina; Urea; Urease
PubMed: 25809221
DOI: 10.1111/jam.12804 -
Foods (Basel, Switzerland) Jul 2023In order to investigate and develop functional foods of marine origin with hypoglycemic activity, polysaccharide-Zn(II) (EZ) complex was first prepared by marine...
In order to investigate and develop functional foods of marine origin with hypoglycemic activity, polysaccharide-Zn(II) (EZ) complex was first prepared by marine resourced polysaccharide (EP) and ZnSO and their anti-diabetes activities against high-sugar and high-fat-induced diabetic mice were evaluated. The detailed structural characterization of EZ was elucidated by UV-Vis spectroscopy, infrared spectroscopy, and monosaccharide composition determination. The pharmacological research suggests that EZ has a potent hypoglycemic effect on high-sugar and high-fat-induced diabetic mice by inhibiting insulin resistance, improving dyslipidemia, decreasing inflammatory status, repairing pancreas damage, as well as activating the IRS/PI3K/AKT signaling pathway and regulating GLUT2 gene expression. At the same time, microbiota analysis indicates that a high dose of EZ could enhance the abundance of dominant species, such as , , , , and , in intestinal microbiota distribution. Thus, EZ could be considered as a potential candidate for developing an ingredient of functional foods for Zn(II) supplements with hypoglycemic activity.
PubMed: 37569125
DOI: 10.3390/foods12152854