{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,23]],"date-time":"2026-06-23T13:03:57Z","timestamp":1782219837222,"version":"3.54.5"},"reference-count":55,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2025,1,17]],"date-time":"2025-01-17T00:00:00Z","timestamp":1737072000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Oral. Health"],"abstract":"<jats:sec><jats:title>Introduction<\/jats:title><jats:p>Dental caries is the most prevalent chronic infectious disease globally, with <jats:italic>Streptococcus mutans<\/jats:italic> recognized as a primary causative agent due to its acidogenicity and robust biofilm-forming ability. In <jats:italic>S. mutans<\/jats:italic> biofilm formation, the role of autoinducers has been extensively studied, while the influence of other small molecules remains largely unexplored. Mutanofactins, a class of polyketide\/non-ribosomal lipopeptide secondary metabolites, are emerging as potential modulators of <jats:italic>S. mutans<\/jats:italic> biofilm development.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>Transcriptomic analysis was conducted to examine gene expression patterns in <jats:italic>S. mutans<\/jats:italic> NMT4863 across distinct growth phases and lifestyles, aiming to identify metabolic factors influencing biofilm formation. Transcriptomic profiles were compared between cells in early-, mid-, and late-exponential-, and stationary phase, as well as between planktonic and biofilm cells. Differentially expressed genes were identified, and pathway analyses revealed significant alterations in key metabolic and regulatory pathways. Specifically, the biosynthetic mutanofactin gene cluster was analyzed via quantitative real-time polymerase chain reaction.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>Several genes and operons were differentially expressed across the tested growth phases, with 1,095 genes showing differential expression between stationary-phase, planktonic and biofilm cells. Pathway analysis revealed significant changes in ascorbate metabolism, carbohydrate utilization and transport systems, lipoic acid metabolism, bacterial toxin pathways, two-component regulatory systems, and secondary metabolite biosynthesis. Notably, expression of the <jats:italic>muf<\/jats:italic> gene cluster, was elevated in early exponential-phase cells relative to stationary-phase cells. Additionally, the <jats:italic>mufCDEFGHIJ<\/jats:italic> genes were identified as components of a single transcriptional unit (<jats:italic>muf<\/jats:italic> operon). MufC, a transcriptional regulator of the TetR\/AcrR-family, acts as a positive regulator of the <jats:italic>muf<\/jats:italic> operon in strain NMT4863. Bioinformatic analysis pinpointed a 20-bp regulatory sequence in the <jats:italic>muf<\/jats:italic> operon promoter region (5\u2032-AAATGAGCTATAATTCATTT-3\u2032). Interestingly, the <jats:italic>muf<\/jats:italic> operon was found to be significantly downregulated in biofilm cells.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusion<\/jats:title><jats:p>This study provides key insights into gene expression dynamics that drive biofilm formation in <jats:italic>S. mutans<\/jats:italic> NMT4863, with a particular emphasis on the role of the <jats:italic>muf<\/jats:italic> operon. This operon is governed by the TetR\/AcrR-family regulator MufC and plays a central role in biofilm development, offering a novel perspective on the molecular basis of <jats:italic>S. mutans<\/jats:italic> biofilm formation and resilience.<\/jats:p><\/jats:sec>","DOI":"10.3389\/froh.2025.1535034","type":"journal-article","created":{"date-parts":[[2025,1,17]],"date-time":"2025-01-17T06:53:14Z","timestamp":1737096794000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":2,"title":["Decoding gene expression dynamics in planktonic and biofilm cells of Streptococcus mutans: regulation and role of mutanofactin genes in biofilm formation"],"prefix":"10.3389","volume":"6","author":[{"given":"Muhammad","family":"Afzal","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Miguel","family":"Carda-Di\u00e9guez","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Susanne","family":"Bloch","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Leon G. S.","family":"Thies","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alex","family":"Mira","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Christina","family":"Sch\u00e4ffer","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2025,1,17]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"764479","DOI":"10.3389\/froh.2022.764479","article-title":"Understanding dental caries as a non-communicable and behavioral disease: management implications","volume":"3","author":"Giacaman","year":"2022","journal-title":"Front Oral Health"},{"key":"B2","doi-asserted-by":"publisher","first-page":"249","DOI":"10.1016\/S0140-6736(19)31146-8","article-title":"Oral diseases: a global public health challenge","volume":"394","author":"Peres","year":"2019","journal-title":"Lancet"},{"key":"B3","doi-asserted-by":"publisher","first-page":"GPP3-0051-2018","DOI":"10.1128\/microbiolspec.GPP3-0051-2018","article-title":"The biology of Streptococcus mutans","volume":"7","author":"Lemos","year":"2019","journal-title":"Microbiol Spectr"},{"key":"B4","doi-asserted-by":"publisher","DOI":"10.3390\/microorganisms8111835","article-title":"Deciphering streptococcal biofilms","volume":"8","author":"Yadav","year":"2020","journal-title":"Microorganisms"},{"key":"B5","doi-asserted-by":"publisher","first-page":"474","DOI":"10.1159\/000108321","article-title":"Real-time monitoring of Streptococcus mutans biofilm formation using a quartz crystal microbalance","volume":"41","author":"Tam","year":"2007","journal-title":"Caries Res"},{"key":"B6","doi-asserted-by":"publisher","first-page":"2225257","DOI":"10.1080\/20002297.2023.2225257","article-title":"Regulatory mechanisms of exopolysaccharide synthesis and biofilm formation in Streptococcus mutans","volume":"15","author":"Zheng","year":"2023","journal-title":"J Oral Microbiol"},{"key":"B7","doi-asserted-by":"publisher","first-page":"667","DOI":"10.1016\/j.dental.2017.03.003","article-title":"Biofilm over teeth and restorations: what do we need to know?","volume":"33","author":"Lin","year":"2017","journal-title":"Dent Mater"},{"key":"B8","doi-asserted-by":"publisher","first-page":"1162380","DOI":"10.3389\/fmicb.2023.1162380","article-title":"Association of polymicrobial interactions with dental caries development and prevention","volume":"14","author":"Zhu","year":"2023","journal-title":"Front Microbiol"},{"key":"B9","doi-asserted-by":"publisher","first-page":"5633","DOI":"10.1128\/AEM.01049-07","article-title":"Acid tolerance of biofilm cells of Streptococcus mutans","volume":"73","author":"Welin-Neilands","year":"2007","journal-title":"Appl Environ Microbiol"},{"key":"B10","doi-asserted-by":"publisher","first-page":"e0261522","DOI":"10.1128\/spectrum.02615-22","article-title":"Quorum sensing and antimicrobial production orchestrate biofilm dynamics in multispecies bacterial communities","volume":"10","author":"Armes","year":"2022","journal-title":"Microbiol Spectr"},{"key":"B11","doi-asserted-by":"publisher","first-page":"ycae006","DOI":"10.1093\/ismeco\/ycae006","article-title":"Succession of microbial community composition and secondary metabolism during marine biofilm development","volume":"4","author":"Bech","year":"2024","journal-title":"ISME Commun"},{"key":"B12","doi-asserted-by":"publisher","first-page":"3010","DOI":"10.1073\/pnas.0730689100","article-title":"Polyketide and non-ribosomal peptide synthases: falling together by coming apart","volume":"100","author":"Hutchinson","year":"2003","journal-title":"Proc Natl Acad Sci"},{"key":"B13","doi-asserted-by":"publisher","first-page":"261","DOI":"10.1111\/omi.12451","article-title":"Polyketides\/nonribosomal peptides from Streptococcus mutans and their ecological roles in dental biofilm","volume":"39","author":"Luo","year":"2024","journal-title":"Mol Oral Microbiol."},{"key":"B14","doi-asserted-by":"publisher","first-page":"1073","DOI":"10.1039\/b514050c","article-title":"Polyketide synthases and nonribosomal peptide synthetases: the emerging view from bacterial genomics","volume":"24","author":"Donadio","year":"2007","journal-title":"Nat Prod Rep"},{"key":"B15","doi-asserted-by":"publisher","first-page":"576","DOI":"10.1038\/s41589-021-00745-2","article-title":"Mutanofactin promotes adhesion and biofilm formation of cariogenic Streptococcus mutans","volume":"17","author":"Li","year":"2021","journal-title":"Nat Chem Biol"},{"key":"B16","doi-asserted-by":"publisher","first-page":"1374","DOI":"10.1128\/JB.182.5.1374-1382.2000","article-title":"Streptococcus gordonii biofilm formation: identification of genes that code for biofilm phenotypes","volume":"182","author":"Loo","year":"2000","journal-title":"J Bacteriol"},{"key":"B17","doi-asserted-by":"publisher","first-page":"866","DOI":"10.1007\/BF02000411","article-title":"Variable fixation of staphylococcal slime by different histochemical fixatives","volume":"12","author":"Baldassarri","year":"1993","journal-title":"Eur J Clin Microbiol Infect Dis"},{"key":"B18","doi-asserted-by":"publisher","first-page":"175","DOI":"10.1016\/S0167-7012(00)00122-6","article-title":"A modified microtiter-plate test for quantification of staphylococcal biofilm formation","volume":"40","author":"Stepanovic","year":"2000","journal-title":"J Micirobiol Meth"},{"key":"B19","doi-asserted-by":"publisher","first-page":"R37","DOI":"10.1186\/gb-2004-5-5-r37","article-title":"Genome2D: a visualization tool for the rapid analysis of bacterial transcriptome data","volume":"5","author":"Baerends","year":"2004","journal-title":"Genome Biol"},{"key":"B20","first-page":"28","article-title":"Fitting a mixture model by expectation maximization to discover motifs in biopolymers","volume":"2","author":"Bailey","year":"1994","journal-title":"Proc Int Conf Intell Syst Mol Biol"},{"key":"B21","doi-asserted-by":"crossref","first-page":"219","DOI":"10.1007\/978-1-4939-6685-1_13","article-title":"Natural transformation of oral streptococci by use of synthetic pheromones","volume-title":"Oral Biology: Molecular Techniques and Applications","author":"Salvadori","year":"2017"},{"key":"B22","doi-asserted-by":"publisher","first-page":"550","DOI":"10.1186\/s13059-014-0550-8","article-title":"Moderated estimation of fold change and dispersion for RNA-Seq data with DESeq2","volume":"15","author":"Love","year":"2014","journal-title":"Genome Biol"},{"key":"B23","doi-asserted-by":"publisher","first-page":"52649","DOI":"10.3791\/52649","article-title":"A fast and reliable pipeline for bacterial transcriptome analysis case study: serine-dependent gene regulation in Streptococcus pneumoniae","volume":"98","author":"Afzal","year":"2015","journal-title":"JoVE"},{"key":"B24","doi-asserted-by":"publisher","first-page":"1101","DOI":"10.1038\/nprot.2008.73","article-title":"Analyzing real-time PCR data by the comparative C(T) method","volume":"3","author":"Schmittgen","year":"2008","journal-title":"Nat Prot"},{"key":"B25","doi-asserted-by":"publisher","first-page":"103","DOI":"10.1016\/S0003-9969(97)00111-8","article-title":"Binding properties of streptococcal glucosyltransferases for hydroxyapatite, saliva-coated hydroxyapatite, and bacterial surfaces","volume":"43","author":"Vacca-Smith","year":"1998","journal-title":"Arch Biol"},{"key":"B26","doi-asserted-by":"publisher","DOI":"10.1128\/AEM.02247-18","article-title":"Glycosyltransferase-mediated biofilm matrix dynamics and virulence of Streptococcus mutans","volume":"85","author":"Rainey","year":"2019","journal-title":"Appl Environ Microbiol"},{"key":"B27","doi-asserted-by":"publisher","first-page":"783","DOI":"10.1016\/j.archoralbio.2004.04.001","article-title":"Contribution of glucan-binding protein C of Streptococcus mutans to bacteremia occurrence","volume":"49","author":"Nomura","year":"2004","journal-title":"Arch Oral Biol"},{"key":"B28","doi-asserted-by":"publisher","first-page":"10389","DOI":"10.1021\/jacs.1c04825","article-title":"Mutanobactin D from the human microbiome: total synthesis, configurational assignment, and biological evaluation","volume":"143","author":"Pultar","year":"2021","journal-title":"J Am Chem Soc"},{"key":"B29","doi-asserted-by":"publisher","first-page":"57","DOI":"10.1111\/j.2041-1014.2011.00634.x","article-title":"The mutacins of Streptococcus mutans: regulation and ecology","volume":"27","author":"Merritt","year":"2012","journal-title":"Mol Oral Microbiol"},{"key":"B30","doi-asserted-by":"publisher","first-page":"981","DOI":"10.1039\/C7NP00029D","article-title":"Nonribosomal peptide synthetase biosynthetic clusters of ESKAPE pathogens","volume":"34","author":"Gulick","year":"2017","journal-title":"Nat Prod Rep"},{"key":"B31","doi-asserted-by":"publisher","first-page":"6605","DOI":"10.1128\/JB.06122-11","article-title":"Regulation of transcription by SMU.1349, a TetR family regulator, in Streptococcus mutans","volume":"193","author":"Chattoraj","year":"2011","journal-title":"J Bacteriol"},{"key":"B32","doi-asserted-by":"publisher","first-page":"e0127221","DOI":"10.1128\/msystems.01272-21","article-title":"Analysis of the Streptococcus mutans proteome during acid and oxidative stress reveals modules of protein coexpression and an expanded role for the TreR transcriptional rgulator","volume":"7","author":"Tinder","year":"2022","journal-title":"mSystems"},{"key":"B33","doi-asserted-by":"publisher","first-page":"1307","DOI":"10.1128\/JB.06071-11","article-title":"Regulation of bacteriocin production and cell death by the VicRK signaling system in Streptococcus mutans","volume":"194","author":"Senadheera","year":"2012","journal-title":"J Bacteriol"},{"key":"B34","doi-asserted-by":"publisher","first-page":"440","DOI":"10.1128\/MMBR.00018-13","article-title":"The TetR family of regulators","volume":"77","author":"Cuthbertson","year":"2013","journal-title":"Microbiol Mol Biol Rev"},{"key":"B35","doi-asserted-by":"publisher","first-page":"927","DOI":"10.3390\/molecules28030927","article-title":"Classification and multifaceted potential of secondary metabolites produced by Bacillus subtilis group: a comprehensive review","volume":"28","author":"Iqbal","year":"2023","journal-title":"Molecules"},{"key":"B36","doi-asserted-by":"publisher","first-page":"e00686","DOI":"10.1016\/j.btre.2021.e00686","article-title":"Molecular genetics of surfactin and its effects on different sub-populations of Bacillus subtilis","volume":"32","author":"Rahman","year":"2021","journal-title":"Biotechnol Rep"},{"key":"B37","doi-asserted-by":"publisher","first-page":"1040","DOI":"10.1099\/jmm.0.001232","article-title":"Streptomyces from traditional medicine: sources of new innovations in antibiotic discovery","volume":"69","author":"Quinn","year":"2020","journal-title":"J Med Microbiol"},{"key":"B38","doi-asserted-by":"crossref","DOI":"10.1007\/978-1-4757-9522-6_1","article-title":"Antibiotics and bioactive microbial metabolites","volume-title":"Biotechnology of Antibiotics and Other Bioactive Microbial Metabolites","author":"Lancini","year":"1993"},{"key":"B39","doi-asserted-by":"publisher","first-page":"6063","DOI":"10.1021\/acs.est.9b07334","article-title":"Cyanopeptide co-production dynamics beyond mirocystins and effects of growth stages and nutrient availability","volume":"54","author":"Natumi","year":"2020","journal-title":"Environ Sci Technol"},{"key":"B40","doi-asserted-by":"publisher","first-page":"15159","DOI":"10.1038\/srep15159","article-title":"Bacterial growth, detachment and cell size control on polyethylene terephthalate surfaces","volume":"5","author":"Wang","year":"2015","journal-title":"Sci Rep"},{"key":"B41","doi-asserted-by":"publisher","first-page":"127526","DOI":"10.1016\/j.micres.2023.127526","article-title":"New strategies and mechanisms for targeting Streptococcus mutans biofilm formation to prevent dental caries: a review","volume":"278","author":"Gao","year":"2024","journal-title":"Microbiol Res"},{"key":"B42","doi-asserted-by":"publisher","first-page":"e00130","DOI":"10.1128\/mBio.00130-21","article-title":"Structural basis of ligand selectivity by a bacterial adhesin lectin involved in multispecies biofilm formation","volume":"12","author":"Guo","year":"2021","journal-title":"mBio"},{"key":"B43","doi-asserted-by":"publisher","DOI":"10.3402\/jom.v6.24878","article-title":"Fueling the caries process: carbohydrate metabolism and gene regulation by Streptococcus mutans","volume":"6","author":"Moye","year":"2014","journal-title":"J Oral Microbiol"},{"key":"B44","doi-asserted-by":"publisher","DOI":"10.1128\/JB.00293-20","article-title":"Characterization of the Streptococcus mutans SMU.1703c-SMU.1702c operon reveals its role in riboflavin import and response to acid stress","volume":"203","author":"Turner","year":"2020","journal-title":"J Bacteriol"},{"key":"B45","doi-asserted-by":"publisher","first-page":"195","DOI":"10.1038\/ijos.2014.38","article-title":"Metabolic activity of Streptococcus mutans biofilms and gene expression during exposure to xylitol and sucrose","volume":"6","author":"Decker","year":"2014","journal-title":"Int J Oral Sci"},{"key":"B46","doi-asserted-by":"publisher","first-page":"e0061022","DOI":"10.1128\/spectrum.00610-22","article-title":"AI-2\/LuxS quorum sensing system promotes biofilm formation of Lactobacillus rhamnosus GG and enhances the resistance to enterotoxigenic Escherichia coli in germ-free zebrafish","volume":"10","author":"Deng","year":"2022","journal-title":"Microbiol Spectr"},{"key":"B47","doi-asserted-by":"publisher","first-page":"2144047","DOI":"10.1080\/20002297.2022.2144047","article-title":"Dual transcriptome of Streptococcus mutans and Candida albicans interplay in biofilms","volume":"15","author":"Xiao","year":"2023","journal-title":"J Oral Microbiol"},{"key":"B48","doi-asserted-by":"publisher","first-page":"51","DOI":"10.1186\/s12866-016-0668-9","article-title":"Identification and functional analysis of the L-ascorbate-specific enzyme II complex of the phosphotransferase system in Streptococcus mutans","volume":"16","author":"Wu","year":"2016","journal-title":"BMC Microbiol"},{"key":"B49","doi-asserted-by":"publisher","first-page":"51","DOI":"10.1186\/1471-2180-10-51","article-title":"Genetic adaptation of Streptococcus mutans during biofilm formation on different types of surfaces","volume":"10","author":"Shemesh","year":"2010","journal-title":"BMC Mcrobiol"},{"key":"B50","doi-asserted-by":"publisher","first-page":"55","DOI":"10.1016\/j.job.2015.12.004","article-title":"Streptococcus mutans biofilm formation is dependent on extracellular DNA in primary low pH conditions","volume":"58","author":"Kawarai","year":"2016","journal-title":"J Oral Biosci"},{"key":"B51","doi-asserted-by":"publisher","first-page":"30","DOI":"10.1038\/s41368-021-00137-1","article-title":"Molecular mechanisms of inhibiting glucosyltransferases for biofilm formation in Streptococcus mutans","volume":"13","author":"Zhang","year":"2021","journal-title":"Int J Oral Sci"},{"key":"B52","doi-asserted-by":"publisher","DOI":"10.3390\/molecules25092232","article-title":"Modulation of lipoteichoic acids and exopolysaccharides prevents Streptococcus mutans biofilm accumulation","volume":"25","author":"Castillo Pedraza","year":"2020","journal-title":"Molecules"},{"key":"B53","doi-asserted-by":"publisher","first-page":"345","DOI":"10.4041\/kjod23.184","article-title":"Managing oral biofilms to avoid enamel demineralization during fixed orthodontic treatment","volume":"53","author":"An","year":"2023","journal-title":"Korean J Orthod"},{"key":"B54","doi-asserted-by":"publisher","first-page":"69","DOI":"10.1159\/000324598","article-title":"Biology of Streptococcus mutans-derived glucosyltransferases: role in extracellular matrix formation of cariogenic biofilms","volume":"45","author":"Bowen","year":"2011","journal-title":"Caries Res"},{"key":"B55","doi-asserted-by":"publisher","first-page":"e13478","DOI":"10.1371\/journal.pone.0013478","article-title":"Dynamics of Streptococcus mutans transcriptome in response to starch and sucrose during biofilm development","volume":"5","author":"Klein","year":"2010","journal-title":"PLoS One"}],"container-title":["Frontiers in Oral Health"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/froh.2025.1535034\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,1,17]],"date-time":"2025-01-17T06:53:16Z","timestamp":1737096796000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/froh.2025.1535034\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,1,17]]},"references-count":55,"alternative-id":["10.3389\/froh.2025.1535034"],"URL":"https:\/\/doi.org\/10.3389\/froh.2025.1535034","relation":{},"ISSN":["2673-4842"],"issn-type":[{"value":"2673-4842","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,1,17]]},"article-number":"1535034"}}