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  • 1
    Online Resource
    Online Resource
    Light Response of Pseudomonas putida KT2440 Mediated by Class II LitR, a Photosensor Homolog
    American Society for Microbiology ; 2020
    In:  Journal of Bacteriology Vol. 202, No. 20 ( 2020-09-23)
    Details
    In: Journal of Bacteriology, American Society for Microbiology, Vol. 202, No. 20 ( 2020-09-23)
    Abstract: Pseudomonas putida KT2440 retains three homologs (PplR1 to PplR3) of the LitR/CarH family, an adenosyl B 12 -dependent light-sensitive MerR family transcriptional regulator. Transcriptome analysis revealed the existence of a number of photoinducible genes, including pplR1 , phrB (encoding DNA photolyase), ufaM (furan-containing fatty acid synthase), folE (GTP cyclohydrolase I), cryB (cryptochrome-like protein), and multiple genes without annotated/known function. Transcriptional analysis by quantitative reverse transcription-PCR with knockout mutants of pplR1 to pplR3 showed that a triple knockout completely abolished the light-inducible transcription in P. putida , which indicates the occurrence of ternary regulation of PplR proteins. A DNase I footprint assay showed that PplR1 protein specifically binds to the promoter regions of light-inducible genes, suggesting a consensus PplR1-binding direct repeat, 5′-T(G/A)TACAN 12 TGTA(C/T)A-3′. The disruption of B 12 biosynthesis cluster did not affect the light-inducible transcription; however, disruption of ppSB1-LOV (where LOV indicates “light, oxygen, or voltage”) and ppSB2-LOV , encoding blue light photoreceptors adjacently located to pplR3 and pplR2 , respectively, led to the complete loss of light-inducible transcription. Overall, the results suggest that the three PplRs and two PpSB-LOVs cooperatively regulate the light-inducible gene expression. The wide distribution of the pplR / ppSB-LOV cognate pair homologs in Pseudomonas spp. and related bacteria suggests that the response and adaptation to light are similarly regulated in the group of nonphototrophic bacteria. IMPORTANCE The LitR/CarH family is a new group of photosensor homologous to MerR-type transcriptional regulators. Proteins of this family are distributed to various nonphototrophic bacteria and grouped into at least five classes (I to V). Pseudomonas putida retaining three class II LitR proteins exhibited a genome-wide response to light. All three paralogs were functional and mediated photodependent activation of promoters directing the transcription of light-induced genes or operons. Two LOV (light, oxygen, or voltage) domain proteins, adjacently encoded by two litR genes, were also essential for the photodependent transcriptional control. Despite the difference in light-sensing mechanisms, the DNA binding consensus of class II LitR [T(G/A)TA(C/T)A] was the same as that of class I. This is the first study showing the actual involvement of class II LitR in light-induced transcription.
    Type of Medium: Online Resource
    ISSN: 0021-9193 , 1098-5530
    URL: Article
    DOI: 10.1128/JB.00146-20
    Language: English
    Publisher: American Society for Microbiology
    Publication Date: 2020
    detail.hit.zdb_id: 1481988-0
    SSG: 12
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  • 2
    Online Resource
    Online Resource
    Molecular cloning and characterization of a cDNA encoding ent ‐cassa‐12,15‐diene synthase, a putative diterpenoid phytoalexin biosynthetic enzyme, from suspension‐cultured rice cells treated with a chitin elicitor
    Wiley ; 2004
    In:  The Plant Journal Vol. 37, No. 1 ( 2004-01), p. 1-8
    Details
    In: The Plant Journal, Wiley, Vol. 37, No. 1 ( 2004-01), p. 1-8
    Abstract: We have isolated and characterized a cDNA encoding a novel diterpene cyclase, OsDTC1, from suspension‐cultured rice cells treated with a chitin elicitor. OsDTC1 functions as ent ‐cassa‐12,15‐diene synthase, which is considered to play a key role in the biosynthesis of (−)‐phytocassanes recently isolated as rice diterpenoid phytoalexins. The expression of OsDTC1 mRNA was also confirmed in ultraviolet (UV)‐irradiated rice leaves. In addition, we identified ent ‐cassa‐12,15‐diene, a putative diterpene hydrocarbon precursor of (−)‐phytocassanes, as an endogenous compound in the chitin‐elicited suspension‐cultured rice cells and the UV‐irradiated rice leaves. The OsDTC1 cDNA isolated here will be a useful tool to investigate the regulatory mechanisms of the biosyntheis of (−)‐phytocassanes in rice.
    Type of Medium: Online Resource
    ISSN: 0960-7412 , 1365-313X
    URL: Article
    DOI: 10.1046/j.1365-313X.2003.01926.x
    Language: English
    Publisher: Wiley
    Publication Date: 2004
    detail.hit.zdb_id: 2020961-7
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  • 3
    Online Resource
    Online Resource
    Novel Toxin-Antitoxin Module SlvT-SlvA Regulates Megaplasmid Stability and Incites Solvent Tolerance in Pseudomonas putida S12
    American Society for Microbiology ; 2020
    In:  Applied and Environmental Microbiology Vol. 86, No. 13 ( 2020-06-17)
    Details
    In: Applied and Environmental Microbiology, American Society for Microbiology, Vol. 86, No. 13 ( 2020-06-17)
    Abstract: Pseudomonas putida S12 is highly tolerant of organic solvents in saturating concentrations, rendering this microorganism suitable for the industrial production of various aromatic compounds. Previous studies revealed that P. putida S12 contains the single-copy 583-kbp megaplasmid pTTS12. pTTS12 carries several important operons and gene clusters facilitating P. putida S12 survival and growth in the presence of toxic compounds or other environmental stresses. We wished to revisit and further scrutinize the role of pTTS12 in conferring solvent tolerance. To this end, we cured the megaplasmid from P. putida S12 and conclusively confirmed that the SrpABC efflux pump is the major determinant of solvent tolerance on the megaplasmid pTTS12. In addition, we identified a novel toxin-antitoxin module (proposed gene names slvT and slvA, respectively) encoded on pTTS12 which contributes to the solvent tolerance phenotype and is important for conferring stability to the megaplasmid. Chromosomal introduction of the srp operon in combination with the slv AT gene pair created a solvent tolerance phenotype in non-solvent-tolerant strains, such as P. putida KT2440, Escherichia coli TG1, and E. coli BL21(DE3). IMPORTANCE Sustainable alternatives for high-value chemicals can be achieved by using renewable feedstocks in bacterial biocatalysis. However, during the bioproduction of such chemicals and biopolymers, aromatic compounds that function as products, substrates, or intermediates in the production process may exert toxicity to microbial host cells and limit the production yield. Therefore, solvent tolerance is a highly preferable trait for microbial hosts in the biobased production of aromatic chemicals and biopolymers. In this study, we revisit the essential role of megaplasmid pTTS12 from solvent-tolerant Pseudomonas putida S12 for molecular adaptation to an organic solvent. In addition to the solvent extrusion pump (SrpABC), we identified a novel toxin-antitoxin module (SlvAT) which contributes to short-term tolerance in moderate solvent concentrations, as well as to the stability of pTTS12. These two gene clusters were successfully expressed in non-solvent-tolerant strains of P. putida and Escherichia coli strains to confer and enhance solvent tolerance.
    Type of Medium: Online Resource
    ISSN: 0099-2240 , 1098-5336
    URL: Article
    DOI: 10.1128/AEM.00686-20
    RVK:
    WA 15000
    Language: English
    Publisher: American Society for Microbiology
    Publication Date: 2020
    detail.hit.zdb_id: 223011-2
    detail.hit.zdb_id: 1478346-0
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  • 4
    Online Resource
    Online Resource
    Involvement of NO 3 − in Ecophysiological Regulation of Dissimilatory Nitrate/Nitrite Reduction to Ammonium (DNRA) Is Implied by Physiological Characterization of Soil DNRA Bacteria Isolated via a Colorimetric Screening Method
    American Society for Microbiology ; 2020
    In:  Applied and Environmental Microbiology Vol. 86, No. 17 ( 2020-08-18)
    Details
    In: Applied and Environmental Microbiology, American Society for Microbiology, Vol. 86, No. 17 ( 2020-08-18)
    Abstract: Dissimilatory nitrate/nitrite reduction to ammonium (DNRA) has recently regained attention as a nitrogen retention pathway that may potentially be harnessed to alleviate nitrogen loss resulting from denitrification. Until recently, the ecophysiology of DNRA bacteria inhabiting agricultural soils has remained largely unexplored, due to the difficulty in targeted enrichment and isolation of DNRA microorganisms. In this study, 〉 100 DNRA bacteria were isolated from NO 3 − -reducing anoxic enrichment cultures established with rice paddy soils using a newly developed colorimetric screening method. Six of these isolates, each assigned to a different genus, were characterized to improve the understanding of DNRA physiology. All the isolates carried nrfA and/or nirB , and the Bacillus sp. strain possessed a clade II nosZ gene conferring the capacity for N 2 O reduction. A common prominent physiological feature observed in the isolates was NO 2 − accumulation before NH 4 + production, which was further examined with Citrobacter sp. strain DNRA3 (possessing nrfA and nirB ) and Enterobacter sp. strain DNRA5 (possessing only nirB ). Both isolates showed inhibition of NO 2 − -to-NH 4 + reduction at submillimolar NO 3 − concentrations and downregulation of nrfA or nirB transcription when NO 3 − was being reduced to NO 2 − . In batch and chemostat experiments, both isolates produced NH 4 + from NO 3 − reduction when incubated with excess organic electron donors, while incubation with excess NO 3 − resulted in NO 2 − buildup but no substantial NH 4 + production, presumably due to inhibitory NO 3 − concentrations. This previously overlooked link between NO 3 − repression of NO 2 − -to-NH 4 + reduction and the C-to-N ratio regulation of DNRA activity may be a key mechanism underpinning denitrification-versus-DNRA competition in soil. IMPORTANCE Dissimilatory nitrate/nitrite reduction to ammonium (DNRA) is an anaerobic microbial pathway that competes with denitrification for common substrates NO 3 − and NO 2 − . Unlike denitrification, which leads to nitrogen loss and N 2 O emission, DNRA reduces NO 3 − and NO 2 − to NH 4 + , a reactive nitrogen compound with a higher tendency to be retained in the soil matrix. Therefore, stimulation of DNRA has often been proposed as a strategy to improve fertilizer efficiency and reduce greenhouse gas emissions. Such attempts have been hampered by lack of insights into soil DNRA bacterial ecophysiology. Here, we have developed a new screening method for isolating DNRA-catalyzing organisms from agricultural soils without apparent DNRA activity. Physiological characteristics of six DNRA isolates were closely examined, disclosing a previously overlooked link between NO 3 − repression of NO 2 − -to-NH 4 + reduction and the C-to-N ratio regulation of DNRA activity, which may be a key to understanding why DNRA activity is rarely observed at substantial levels in nitrogen-rich agricultural soils.
    Type of Medium: Online Resource
    ISSN: 0099-2240 , 1098-5336
    URL: Article
    DOI: 10.1128/AEM.01054-20
    RVK:
    WA 15000
    Language: English
    Publisher: American Society for Microbiology
    Publication Date: 2020
    detail.hit.zdb_id: 223011-2
    detail.hit.zdb_id: 1478346-0
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  • 5
    Online Resource
    Online Resource
    Beneficial Biofilms: a Minireview of Strategies To Enhance Biofilm Formation for Biotechnological Applications
    American Society for Microbiology ; 2022
    In:  Applied and Environmental Microbiology Vol. 88, No. 3 ( 2022-02-08)
    Details
    In: Applied and Environmental Microbiology, American Society for Microbiology, Vol. 88, No. 3 ( 2022-02-08)
    Abstract: The capacity of bacteria to form biofilms is an important trait for their survival and persistence. Biofilms occur naturally in soil and aquatic environments, are associated with animals ranging from insects to humans, and are also found in built environments. They are typically encountered as a challenge in health care, food industry, and water supply ecosystems. In contrast, they are known to play a key role in the industrial production of commercially valuable products, environmental remediation processes, and microbe-catalyzed electrochemical systems for energy and resource recovery from wastewater. While there are many recent articles on biofilm control and removal, review articles on promoting biofilm growth for biotechnological applications are unavailable. Biofilm formation is a tightly regulated response to perturbations in the external environment. The multistage process, mediated by an assortment of proteins and signaling systems, involves the attachment of bacterial cells to a surface followed by their aggregation in a matrix of extracellular polymeric substances. Biofilms can be promoted by altering the external environment in a controlled manner, supplying molecules that trigger the aggregation of cells and engineering genes associated with biofilm development. This minireview synthesizes findings from studies that have described such strategies and highlights areas needing research attention.
    Type of Medium: Online Resource
    ISSN: 0099-2240 , 1098-5336
    URL: Article
    DOI: 10.1128/AEM.01994-21
    RVK:
    WA 15000
    Language: English
    Publisher: American Society for Microbiology
    Publication Date: 2022
    detail.hit.zdb_id: 223011-2
    detail.hit.zdb_id: 1478346-0
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  • 6
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    Online Resource
    Temperature and Nutrient Levels Correspond with Lineage-Specific Microdiversification in the Ubiquitous and Abundant Freshwater Genus Limnohabitans
    American Society for Microbiology ; 2020
    In:  Applied and Environmental Microbiology Vol. 86, No. 10 ( 2020-05-05)
    Details
    In: Applied and Environmental Microbiology, American Society for Microbiology, Vol. 86, No. 10 ( 2020-05-05)
    Abstract: Most freshwater bacterial communities are characterized by a few dominant taxa that are often ubiquitous across freshwater biomes worldwide. Our understanding of the genomic diversity within these taxonomic groups is limited to a subset of taxa. Here, we investigated the genomic diversity that enables Limnohabitans , a freshwater genus key in funneling carbon from primary producers to higher trophic levels, to achieve abundance and ubiquity. We reconstructed eight putative Limnohabitans metagenome-assembled genomes (MAGs) from stations located along broad environmental gradients existing in Lake Michigan, part of Earth’s largest surface freshwater system. De novo strain inference analysis resolved a total of 23 strains from these MAGs, which strongly partitioned into two habitat-specific clusters with cooccurring strains from different lineages. The largest number of strains belonged to the abundant LimB lineage, for which robust in situ strain delineation had not previously been achieved. Our data show that temperature and nutrient levels may be important environmental parameters associated with microdiversification within the Limnohabitans genus. In addition, strains predominant in low- and high-phosphorus conditions had larger genomic divergence than strains abundant under different temperatures. Comparative genomics and gene expression analysis yielded evidence for the ability of LimB populations to exhibit cellular motility and chemotaxis, a phenotype not yet associated with available Limnohabitans isolates. Our findings broaden historical marker gene-based surveys of Limnohabitans microdiversification and provide in situ evidence of genome diversity and its functional implications across freshwater gradients. IMPORTANCE Limnohabitans is an important bacterial taxonomic group for cycling carbon in freshwater ecosystems worldwide. Here, we examined the genomic diversity of different Limnohabitans lineages. We focused on the LimB lineage of this genus, which is globally distributed and often abundant, and its abundance has shown to be largely invariant to environmental change. Our data show that the LimB lineage is actually comprised of multiple cooccurring populations for which the composition and genomic characteristics are associated with variations in temperature and nutrient levels. The gene expression profiles of this lineage suggest the importance of chemotaxis and motility, traits that had not yet been associated with the Limnohabitans genus, in adapting to environmental conditions.
    Type of Medium: Online Resource
    ISSN: 0099-2240 , 1098-5336
    URL: Article
    DOI: 10.1128/AEM.00140-20
    RVK:
    WA 15000
    Language: English
    Publisher: American Society for Microbiology
    Publication Date: 2020
    detail.hit.zdb_id: 223011-2
    detail.hit.zdb_id: 1478346-0
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  • 7
    Online Resource
    Online Resource
    CosR Is a Global Regulator of the Osmotic Stress Response with Widespread Distribution among Bacteria
    American Society for Microbiology ; 2020
    In:  Applied and Environmental Microbiology Vol. 86, No. 10 ( 2020-05-05)
    Details
    In: Applied and Environmental Microbiology, American Society for Microbiology, Vol. 86, No. 10 ( 2020-05-05)
    Abstract: Bacteria accumulate small, organic compounds called compatible solutes via uptake from the environment or biosynthesis from available precursors to maintain the turgor pressure of the cell in response to osmotic stress. The halophile Vibrio parahaemolyticus has biosynthesis pathways for the compatible solutes ectoine (encoded by ectABC-asp_ect ) and glycine betaine (encoded by betIBA-proXWV ), four betaine-carnitine-choline transporters (encoded by bccT1 to bccT4 ), and a second ProU transporter (encoded by proVWX ). All of these systems are osmotically inducible with the exception of bccT2 . Previously, it was shown that CosR, a MarR-type regulator, was a direct repressor of ectABC-asp_ect in Vibrio species. In this study, we investigated whether CosR has a broader role in the osmotic stress response. Expression analyses demonstrated that betIBA-proXWV , bccT1 , bccT3 , bccT4 , and proVWX are repressed in low salinity. Examination of an in-frame cosR deletion mutant showed that expression of these systems is derepressed in the mutant at low salinity compared with the wild type. DNA binding assays demonstrated that purified CosR binds directly to the regulatory region of both biosynthesis systems and four transporters. In Escherichia coli green fluorescent protein (GFP) reporter assays, we demonstrated that CosR directly represses transcription of betIBA-proXWV , bccT3 , and proVWX . Similar to Vibrio harveyi , we showed betIBA-proXWV was directly activated by the quorum-sensing LuxR homolog OpaR, suggesting a conserved mechanism of regulation among Vibrio species. Phylogenetic analysis demonstrated that CosR is ancestral to the Vibrionaceae family, and bioinformatics analysis showed widespread distribution among Gammaproteobacteria in general. Incidentally, in Aliivibrio fischeri , Aliivibrio finisterrensis , Aliivibrio sifiae , and Aliivibrio wodanis , an unrelated MarR-type regulator gene named ectR was clustered with ectABC-asp , which suggests the presence of another novel ectoine biosynthesis regulator. Overall, these data show that CosR is a global regulator of osmotic stress response that is widespread among bacteria. IMPORTANCE Vibrio parahaemolyticus can accumulate compatible solutes via biosynthesis and transport, which allow the cell to survive in high salinity conditions. There is little need for compatible solutes under low salinity conditions, and biosynthesis and transporter systems need to be repressed. However, the mechanism(s) of this repression is not known. In this study, we showed that CosR played a major role in the regulation of multiple compatible solute systems. Phylogenetic analysis showed that CosR is present in all members of the Vibrionaceae family as well as numerous Gammaproteobacteria . Collectively, these data establish CosR as a global regulator of the osmotic stress response that is widespread in bacteria, controlling many more systems than previously demonstrated.
    Type of Medium: Online Resource
    ISSN: 0099-2240 , 1098-5336
    URL: Article
    DOI: 10.1128/AEM.00120-20
    RVK:
    WA 15000
    Language: English
    Publisher: American Society for Microbiology
    Publication Date: 2020
    detail.hit.zdb_id: 223011-2
    detail.hit.zdb_id: 1478346-0
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  • 8
    Online Resource
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    Single-Component and Two-Component para -Nitrophenol Monooxygenases: Structural Basis for Their Catalytic Difference
    American Society for Microbiology ; 2021
    In:  Applied and Environmental Microbiology Vol. 87, No. 22 ( 2021-10-28)
    Details
    In: Applied and Environmental Microbiology, American Society for Microbiology, Vol. 87, No. 22 ( 2021-10-28)
    Abstract: para -Nitrophenol (PNP) is a hydrolytic product of organophosphate insecticides, such as parathion and methylparathion, in soil. Aerobic microbial degradation of PNP has been classically shown to proceed via the “hydroquinone (HQ) pathway” in Gram-negative degraders, whereas it proceeds via the “benzenetriol (BT) pathway” in Gram-positive ones. The “HQ pathway” is initiated by a single-component PNP 4-monooxygenase and the “BT pathway” by a two-component PNP 2-monooxygenase. Their regioselectivity intrigued us enough to investigate their catalytic difference through structural study. PnpA1 is the oxygenase component of the two-component PNP 2-monooxygenase from Gram-positive Rhodococcus imtechensis strain RKJ300. It also catalyzes the hydroxylation of 4-nitrocatechol (4NC) and 2-chloro-4-nitrophenol (2C4NP). However, the mechanisms are unknown. Here, PnpA1 was structurally determined to be a member of the group D flavin-dependent monooxygenases with an acyl coenzyme A (acyl-CoA) dehydrogenase fold. The crystal structure and site-directed mutagenesis underlined the direct involvement of Arg100 and His293 in catalysis. The bulky side chain of Val292 was proposed to push the substrate toward flavin adenine dinucleotide (FAD), hence positioning the substrate properly. An N450A variant was found with improved activity for 4NC and 2C4NP—probably because of the reduced steric hindrance. PnpA1 shows an obvious difference in substrate selectivity with its close homologues TcpA and TftD, which may be caused by the unique Thr296 and a different conformation in the loop from positions 449 to 454 (loop 449–454). Above all, our study allows structural comparison between the two types of PNP monooxygenases. An explanation that accounts for their regioselectivity was proposed: the different PNP binding manners determine their choice of ortho - or para -hydroxylation on PNP. IMPORTANCE Single-component PNP monoxygenases hydroxylate PNP at the 4 position, while two-component ones do so at the 2 position. However, their catalytic and structural differences remain elusive. The structure of single-component PNP 4-monooxygenase has previously been determined. In this study, to illustrate their catalytic difference, we resolved the crystal structure of PnpA1, a typical two-component PNP 2-monooxygenase. The roles of several key amino acid residues in substrate binding and catalysis were revealed, and a variant with improved activities toward 4NC and 2C4NP was obtained. Moreover, through comparison of the two types of PNP monooxygenases, a hypothesis was proposed to account for their catalytic difference, which gives us a better understanding of these two similar reactions at the molecular level. In addition, these results will also be of further aid in rational design of enzymes in bioremediation and biosynthesis.
    Type of Medium: Online Resource
    ISSN: 0099-2240 , 1098-5336
    URL: Article
    DOI: 10.1128/AEM.01171-21
    RVK:
    WA 15000
    Language: English
    Publisher: American Society for Microbiology
    Publication Date: 2021
    detail.hit.zdb_id: 223011-2
    detail.hit.zdb_id: 1478346-0
    SSG: 12
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  • 9
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    Multiomic Analyses Reveal the Effects of Supplementing Phytosterols on the Metabolic Function of the Rumen Microbiota in Perinatal Cows
    American Society for Microbiology ; 2022
    In:  Applied and Environmental Microbiology Vol. 88, No. 15 ( 2022-08-09)
    Details
    In: Applied and Environmental Microbiology, American Society for Microbiology, Vol. 88, No. 15 ( 2022-08-09)
    Abstract: Phytosterols are natural steroids in plants, possessing bioactivities that could modify gut microbes. This experiment aimed to evaluate the effects of feeding phytosterols on the community structures and metabolic functions of the rumen microbiota in perinatal cows. Perinatal cows were supplied with 0 mg (control) or 200 mg (treatment) phytosterols per day. Multiomic analyses were used to analyze the community structures and metabolic functions of rumen microbiota. Results showed that dietary phytosterols increased the copy number of total ruminal bacteria, the concentration of microbial crude protein, and the molar percentage of propionate in the rumen of perinatal cows but had no effects on the alpha diversity of ruminal bacteria. However, they enriched three genera (i.e., Fibrobacter ) and seven species (i.e., Fibrobacter succinogenes ) within active ruminal bacteria. Metatranscriptomic and metabolomic analyses revealed that dietary phytosterols enhanced the pathway of glycolysis and the family of glycoside hydrolase 13 but depressed the citrate cycle and pyruvate metabolism and several pathways of amino acid biosynthesis. In conclusion, dietary addition of phytosterols improved the growth of ruminal bacteria and changed rumen fermentation by modifying the rumen microbiome and the energy metabolism pathways, which would be beneficial for the energy utilization of perinatal cows. IMPORTANCE Perinatal cows suffer serious physiological stress and energy deficiency. Phytosterols have bioactive functions for gut microbes. However, little knowledge is available on their effects on rumen microbiota and rumen fermentation. Results of the present experiment revealed that dietary supplementation of phytosterols could improve the growth of ruminal bacteria and changed the rumen fermentation to provide more glycogenetic precursors for the perinatal cows by modifying the ruminal bacteria community and altering the energy metabolism pathways of the rumen microbiota. These findings suggest that dietary supplementation of phytosterols would be beneficial for perinatal cows suffering from a negative energy balance.
    Type of Medium: Online Resource
    ISSN: 0099-2240 , 1098-5336
    URL: Article
    DOI: 10.1128/aem.00992-22
    RVK:
    WA 15000
    Language: English
    Publisher: American Society for Microbiology
    Publication Date: 2022
    detail.hit.zdb_id: 223011-2
    detail.hit.zdb_id: 1478346-0
    SSG: 12
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  • 10
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    Antimicrobial Peptide GH12 Prevents Dental Caries by Regulating Dental Plaque Microbiota
    American Society for Microbiology ; 2020
    In:  Applied and Environmental Microbiology Vol. 86, No. 14 ( 2020-07-02)
    Details
    In: Applied and Environmental Microbiology, American Society for Microbiology, Vol. 86, No. 14 ( 2020-07-02)
    Abstract: Due to the complex microecology and microenvironment of dental plaque, novel caries prevention strategies require modulating the microbial communities ecologically and reducing the cariogenic properties effectively. Antimicrobial peptide GH12 reduced the lactic acid production and exopolysaccharide (EPS) synthesis of a Streptococcus mutans biofilm and a three-species biofilm in vitro in previous studies. However, the anticaries effects and microecological effects of GH12 remained to be investigated in a complex biofilm model in vitro and an animal caries model in vivo . In the present study, GH12 at 64 mg/liter showed the most effective inhibition of lactic acid production, EPS synthesis, pH decline, and biofilm integrity of human dental plaque-derived multispecies biofilms in vitro , and GH12 at 64 mg/liter was therefore chosen for use in subsequent in vitro and in vivo assays. When treated with 64-mg/liter GH12, the dental plaque-derived multispecies biofilms sampled from healthy volunteers maintained its microbial diversity and showed a microbial community structure similar to that of the control group. In the rat caries model with a caries-promoting diet, 64-mg/liter GH12 regulated the microbiota of dental plaque, in which the abundance of caries-associated bacteria was decreased and the abundance of commensal bacteria was increased. In addition, 64-mg/liter GH12 significantly reduced the caries scores of sulcal and smooth surface caries in all locations. In conclusion, GH12 inhibited the cariogenic properties of dental plaque without perturbing the dental plaque microbiota of healthy individuals and GH12 regulated the dysbiotic microbial ecology and arrested caries development under cariogenic conditions. IMPORTANCE The anticaries effects and microecological regulation effects of the antimicrobial peptide GH12 were evaluated systematically in vitro and in vivo . GH12 inhibited the cariogenic virulence of dental plaque without overintervening in the microbial ecology of healthy individuals in vitro . GH12 regulated the microbial ecology of dental plaque to a certain extent in vivo under cariogenic conditions, increased the proportion of commensal bacteria, and decreased the abundance of caries-associated bacteria. GH12 significantly suppressed the incidence and severity of dental caries in vivo . This study thus describes an alternative antimicrobial therapy for dental caries.
    Type of Medium: Online Resource
    ISSN: 0099-2240 , 1098-5336
    URL: Article
    DOI: 10.1128/AEM.00527-20
    RVK:
    WA 15000
    Language: English
    Publisher: American Society for Microbiology
    Publication Date: 2020
    detail.hit.zdb_id: 223011-2
    detail.hit.zdb_id: 1478346-0
    SSG: 12
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