9 research outputs found
Pan-Genome Portrait of Bacillus mycoides Provides Insights into the Species Ecology and Evolution
Bacillus mycoides is poorly known despite its frequent occurrence in a wide variety of environments. To provide direct insight into its ecology and evolutionary history, a comparative investigation of the species pan-genome and the functional gene categorization of 35 isolates obtained from soil samples from northeastern Poland was performed. The pan-genome of these isolates is composed of 20,175 genes and is characterized by a strong predominance of adaptive genes (∼83%), a significant amount of plasmid genes (∼37%), and a great contribution of prophages and insertion sequences. The pan-genome structure and phylodynamic studies had suggested a wide genomic diversity among the isolates, but no correlation between lineages and the bacillus origin was found. Nevertheless, the two B. mycoides populations, one from BiaÅ‚owieża National Park, the last European natural primeval forest with soil classified as organic, and the second from mineral soil samples taken in a farm in Jasienówka, a place with strong anthropogenic pressure, differ significantly in the frequency of genes encoding proteins enabling bacillus adaptation to specific stress conditions and production of a set of compounds, thus facilitating their colonization of various ecological niches. Furthermore, differences in the prevalence of essential stress sigma factors might be an important trail of this process. Due to these numerous adaptive genes, B. mycoides is able to quickly adapt to changing environmental conditions.Izabela ÅšwiÄ™cicka: [email protected] Fiedoruk - Department of Microbiology, Medical University of Bialystok, Bialystok, PolandJustyna M. Drewnowska - Department of Microbiology, Faculty of Biology, University of Bialystok, Bialystok, PolandJacques Mahillon - Laboratory of Food and Environmental Microbiology, Earth and Life Institute, Université Catholique de Louvain, Louvain-la-Neuve, BelgiumMonika Zambrzycka - Department of Microbiology, Faculty of Biology, University of Bialystok, Bialystok, PolandIzabela ÅšwiÄ™cicka - Department of Microbiology, Faculty of Biology, University of Bialystok, Bialystok, Poland; Laboratory of Applied Microbiology, Faculty of Biology, University of Bialystok, Bialystok, PolandSwiecicka I, De Vos P. 2003. Properties of Bacillus thuringiensis isolated from bank voles. J Appl Microbiol 94:60–64. https://doi.org/10.1046/j.1365-2672.2003.01790.x.Ceuppens S, Boon N, Uyttendaele M. 2013. Diversity of Bacillus cereus group strains is reflected in their broad range of pathogenicity and diverse ecological lifestyles. FEMS Microbiol Ecol 84:433–450. https://doi.org/10.1111/1574-6941.12110.Vidic J, Chaix C, Manzano M, Heyndrickx M. 2020. Food sensing: detection of Bacillus cereus spores in dairy products. Biosensors 10:15. https://doi.org/10.3390/bios10030015.Swiecicka I. 2008. Natural occurrence of Bacillus thuringiensis and Bacillus cereus in eukaryotic organisms: a case for symbiosis. Biocontrol Sci Technol 18:221–239. https://doi.org/10.1080/09583150801942334.Mock M, Fouet A. 2001. Anthrax. Annu Rev Microbiol 55:647–671. https://doi.org/10.1146/annurev.micro.55.1.647.Stenfors Arnesen LP, Fagerlund A, Granum PE. 2008. From soil to gut: Bacillus cereus and its food poisoning toxins. FEMS Microbiol Rev 32:579–606. https://doi.org/10.1111/j.1574-6976.2008.00112.x.Drewnowska JM, Stefanska N, Czerniecka M, Zambrowski G, Swiecicka I.2020. Potential enterotoxicity of phylogenetically diverse Bacillus cereus sensu lato soil isolates from different geographical locations. Appl Environ Microbiol 86:e03032-19. https://doi.org/10.1128/AEM.03032-19.Swiecicka I, Bideshi DK, Federici BA. 2008. Novel isolate of Bacillus thuringiensis subsp. thuringiensis that produces a quasicuboidal crystal of Cry1Ab21 toxic to larvae of Trichoplusia ni. Appl Environ Microbiol 74:923–930. https://doi.org/10.1128/AEM.01955-07.Jiménez G, Blanch AR, Tamames J, Rosselló-Mora R. 2013. Complete genome sequence of Bacillus toyonensis BCT-7112T, the active ingredient of the feed additive preparation Toyocerin. Genome Announc 1:e01080-13. https://doi.org/10.1128/genomeA.01080-13.Liu Y, Lai Q, Shao Z. 2018. Genome analysis-based reclassification of Bacillus weihenstephanensis as a later heterotypic synonym of Bacillus mycoides. Int J Syst Evol Microbiol 68:106–112. https://doi.org/10.1099/ijsem.0.002466.Lechner S, Mayr R, Francis K, Prüss BM, Kaplan T, Wiessner-Gunkel E, Stewart GS, Scherer S. 1998. Bacillus weihenstephanensis sp. nov. is a new psychrotolerant species of the Bacillus cereus group. Int J Syst Bacteriol 48:1373–1382. https://doi.org/10.1099/00207713-48-4-1373.Liu Y, Lai Q, Göker M, Meier-Kolthoff JP, Wang M, Sun Y, Wang L, Shao Z. 2015. Genomic insights into the taxonomic status of the Bacillus cereus group. Sci Rep 5:14082. https://doi.org/10.1038/srep14082.Drewnowska JM, Swiecicka I. 2013. Eco-genetic structure of Bacillus cereus sensu lato populations from different environments in Northeastern Poland. PLoS One 8:e80175. https://doi.org/10.1371/journal.pone.0080175.Soufiane B, Côté J-C. 2013. Bacillus weihenstephanensis characteristics are present in Bacillus cereus and Bacillus mycoides strains. FEMS Microbiol Lett 341:127–137. https://doi.org/10.1111/1574-6968.12106.Guinebretière M-H, Thompson FL, Sorokin A, Normand P, Dawyndt P, Ehling-Schulz M, Svensson B, Sanchis V, Nguyen-The C, Heyndrickx M, De Vos P. 2008. Ecological diversification in the Bacillus cereus group. Environ Microbiol 10:851–865. https://doi.org/10.1111/j.1462-2920.2007.01495.x.Swiecicka I, Bartoszewicz M, Kasulyte-Creasey D, Drewnowska JM, Murawska E, Yernazarova A, Lukaszuk E, Mahillon J. 2013. Diversity of thermal ecotypes and potential pathotypes of Bacillus thuringiensis soil isolates. FEMS Microbiol Ecol 85:262–272. https://doi.org/10.1111/1574-6941.12116.Fiedoruk K, Drewnowska JM, Daniluk T, Leszczynska K, Iwaniuk P, Swiecicka I. 2017. Ribosomal background of the Bacillus cereus group thermotypes. Sci Rep 7:46430. https://doi.org/10.1038/srep46430.Drewnowska JM, Fiodor A, Barboza-Corona JE, Swiecicka I. 2020. Chitinolytic activity of phylogenetically diverse Bacillus cereus sensu lato from natural environments. Syst Appl Microbiol 43:126075. https://doi.org/10.1016/j.syapm.2020.126075.Drewnowska JM, Zambrzycka M, Kalska-Szostko B, Fiedoruk K, Swiecicka I. 2015. Melanin-like pigment synthesis by soil Bacillus weihenstephanensis isolates from Northeastern Poland. PLoS One 10:e0125428. https://doi.org/10.1371/journal.pone.0125428.Makart L, Commans F, Gillis A, Mahillon J. 2017. Horizontal transfer of chromosomal markers mediated by the large conjugative plasmid pXO16 from Bacillus thuringiensis serovar israelensis. Plasmid 91:76–81. https://doi.org/10.1016/j.plasmid.2017.04.001.Hu X, Huang D, Ogalo J, Geng P, Yuan Z, Xiong H, Wan X, Sun J. 2020. Application of Bacillus thuringiensis strains with conjugal and mobilizing capability drives gene transmissibility within Bacillus cereus group populations in confined habitats. BMC Microbiol 20:363. https://doi.org/10.1186/s12866-020-02047-4.Swiecicka I, Mahillon J. 2005. The clonal structure of Bacillus thuringiensis isolates from north-east Poland does not correlate with their cry gene diversity. Environ Microbiol 7:34–39. https://doi.org/10.1111/j.1462-2920.2004.00662.xVan der Auwera G, Mahillon J. 2008. Transcriptional analysis of the conjugative plasmid pAW63 from Bacillus thuringiensis. Plasmid 60:190–199. https://doi.org/10.1016/j.plasmid.2008.07.003.Fiedoruk K, Daniluk T, Mahillon J, Leszczynska K, Swiecicka I. 2017. Genetic environment of cry1 genes indicates their common origin. Genome Biol Evol 9:2265–2275. https://doi.org/10.1093/gbe/evx165.Fayad N, Kallassy Awad M, Mahillon J. 2019. Diversity of Bacillus cereus sensu lato mobilome. BMC Genomics 20:436. https://doi.org/10.1186/s12864-019-5764-4.Gillis A, Fayad N, Makart L, Bolotin A, Sorokin A, Kallassy M, Mahillon J. 2018. Role of plasmid plasticity and mobile genetic elements in the entomopathogen Bacillus thuringiensis serovar isrealensis. FEMS Microbiol Rev 42:829–856. https://doi.org/10.1093/femsre/fuy034.Medini D, Donati C, Tettelin H, Masignani V, Rappuoli R. 2005. The microbial pan-genome. Curr Opin Genet Dev 15:589–594. https://doi.org/10.1016/j.gde.2005.09.006.Yu J, Zhao J, Song Y, Zhang J, Yu Z, Zhang H, Sun Z. 2018. Comparative genomics of the herbivore gut symbiont Lactobacillus reuteri reveals genetic diversity and lifestyle adaptation. Front Microbiol 9:1151. https://doi.org/10.3389/fmicb.2018.01151.Azarian T, Huang I-T, Hanage WP. 2020. Structure and dynamics of bacterial populations: pangenome ecology, p 115–128. In Tettelin H, Medini D (ed), The pangenome: diversity, dynamics and evolution of genomes. Springer International Publishing, Cham, Switzerland.Laing CR, Whiteside MD, Gannon VPJ. 2017. Pan-genome analyses of the species Salmonella enterica, and identification of genomic markers predictive for species, subspecies, and serovar. Front Microbiol 8:1345. https://doi.org/10.3389/fmicb.2017.01345.Zhang X, Liu Z, Wei G, Yang F, Liu X. 2018. In silico genome-wide analysis reveals the potential links between core genome of Acidithiobacillus thiooxidans and its autotrophic lifestyle. Front Microbiol 9:1255. https://doi.org/10.3389/fmicb.2018.01255.Romaniuk K, Golec P, Dziewit L. 2018. Insight into the diversity and possible role of plasmids in the adaptation of psychrotolerant and metalotolerant Arthrobacter spp. to extreme Antarctic environments. Front Microbiol 9:3144. https://doi.org/10.3389/fmicb.2018.03144.Koskella B, Vos M. 2015. Adaptation in natural microbial populations. Annu Rev Ecol Evol Syst 46:503–522. https://doi.org/10.1146/annurev-ecolsys-112414-054458.Inglin RC, Meile L, Stevens MJA. 2018. Clustering of pan- and core-genome of Lactobacillus provides novel evolutionary insights for differentiation. BMC Genomics 19:284. https://doi.org/10.1186/s12864-018-4601-5.Bazinet AL. 2017. Pan-genome and phylogeny of Bacillus cereus sensu lato. BMC Evol Biol 17:176. https://doi.org/10.1186/s12862-017-1020-1.Nourdin-Galindo G, Sánchez P, Molina CF, Espinoza-Rojas DA, Oliver C, Ruiz P, Vargas-Chacoff L, Cárcamo JG, Figueroa JE, Mancilla M, MaracajaCoutinho V, Yañez AJ. 2017. Comparative pan-genome analysis of Piscirickettsia salmonis reveals genomic divergences within genogroups. Front Cell Infect Microbiol 7:459. https://doi.org/10.3389/fcimb.2017.00459.Collingro A, Tischler P, Weinmaier T, Penz T, Heinz E, Brunham RC, Read TD, Bavoil PM, Sachse K, Kahane S, Friedman MG, Rattei T, Myers GSA, Horn M. 2011. Unity in variety–the pan-genome of the Chlamydiae. Mol Biol Evol 28:3253–3270. https://doi.org/10.1093/molbev/msr161.Kim Y, Koh I, Young Lim M, Chung W-H, Rho M. 2017. Pan-genome analysis of Bacillus for microbiome profiling. Sci Rep 7:10984. https://doi.org/10.1038/s41598-017-11385-9.Hoton FM, Andrup L, Swiecicka I, Mahillon J. 2005. The cereulide genetic determinants of emetic Bacillus cereus are plasmid-borne. Microbiology (Reading) 151:2121–2124. https://doi.org/10.1099/mic.0.28069-0.Murawska E, Fiedoruk K, Swiecicka I. 2014. Modular genetic architecture of the toxigenic plasmid pIS56-63 harboring cry1Ab21 in Bacillus thuringiensis subsp. thuringiensis strain IS5056. Pol J Microbiol 63:147–156. https://doi.org/10.33073/pjm-2014-020.Mahillon J, Chandler M. 1998. Insertion sequences. Microbiol Mol Biol Rev 62:725–774. https://doi.org/10.1128/MMBR.62.3.725-774.1998.Pinto D, da Fonseca RR. 2020. Evolution of the extracytoplasmic function s factor protein family. NAR Genom Bioinform 2:lqz026. https://doi.org/10.1093/nargab/lqz026.Schmidt TR, Scott EJ, Dyer DW. 2011. Whole-genome phylogenies of the family Bacillaceae and expansion of the sigma factor gene family in the Bacillus cereus species-group. BMC Genomics 12:430. https://doi.org/10.1186/1471-2164-12-430.Van Schaik W, Tempelaars MH, Wouters JA, de Vos WM, Abee T. 2004. The alternative sigma factor sB of Bacillus cereus: response to stress and role in heat adaptation. J Bacteriol 186:316–325. https://doi.org/10.1128/JB.186.2.316-325.2004.Fayad N, Kambris Z, El Chamy L, Mahillon J, Kallassy Awad M. 2021. A novel antidipterian Bacillus thuringiensis strain: unusual Cry toxin genes in a high dynamic plasmid environment. Appl Environ Microbiol 87:e02294-20. https://doi.org/10.1128/AEM.02294-20.Carroll LM, Wiedmann M, Kovac J. 2020. Proposal of a taxonomic nomenclature for the Bacillus cereus group which reconciles genomic definitions of bacterial species with clinical and industrial phenotypes. mBio 11: e00034-20. https://doi.org/10.1128/mBio.00034-20.Yoshida K-i, Yamaguchi M, Morinaga T, Kinehara M, Ikeuchi M, Ashida H, Fujita Y. 2008. myo-Inositol catabolism in Bacillus subtilis. J Biol Chem 283:10415–10424. https://doi.org/10.1074/jbc.M708043200.Gonzalez-Uarquin F, Rodehutscord M, Huber K. 2020. myo-Inositol: its metabolism and potential implication for poultry nutrition – a review. Poult Sci 99:893–905. https://doi.org/10.1016/j.psj.2019.10.014.Xin B, Zheng J, Xu Z, Song X, Ruan L, Peng D, Sun M. 2015. The Bacillus cereus group is an excellent reservoir of novel lanthipeptides. Appl Environ Microbiol 81:1765–1774. https://doi.org/10.1128/AEM.03758-14.Wu J, Samara NL, Kuraoka I, Yang W. 2019. Evolution of inosine-specific endonuclease V from bacterial DNase to eukaryotic RNase. Mol Cell 76:44–56. https://doi.org/10.1016/j.molcel.2019.06.046.Caulier S, Nannan C, Gillis A, Licciardi F, Bragard C, Mahillon J. 2019. Overview of the antimicrobial compounds produced by members of the Bacillus subtilis group. Front Microbiol 10:302. https://doi.org/10.3389/fmicb.2019.00302.de la Fuente-Salcido N, Guadalupe AlanÃs-Guzmán M, Bideshi DK, SalcedoHernández R, Bautista-Justo M, Barboza-Corona JE. 2008. Enhanced synthesis and antimicrobial activities of bacteriocins produced by Mexican strains of Bacillus thuringiensis. Arch Microbiol 190:633–640. https://doi.org/10.1007/s00203-008-0414-2.Abriouel H, Franz CMAP, Omar NB, Gálvez A. 2011. Diversity and applications of Bacillus bacteriocins. FEMS Microbiol Rev 35:201–232. https://doi.org/10.1111/j.1574-6976.2010.00244.x.Raymond B, Wyres KL, Sheppard SK, Ellis RJ, Bonsall MB. 2010. Environmental factors determining the epidemiology and population genetic structure of the Bacillus cereus group in the field. PLoS Pathog 6: e1000905. https://doi.org/10.1371/journal.ppat.1000905.Bolger AM, Lohse M, Usadel B. 2014. Trimmomatic: a flexible trimmer for Illumina sequence data. Bioinformatics 30:2114–2120. https://doi.org/10.1093/bioinformatics/btu170.Page AJ, Cummins CA, Hunt M, Wong VK, Reuter S, Holden MTG, Fookes M, Falush D, Keane JA, Parkhill J. 2015. Roary: rapid large-scale prokaryote pan genome analysis. Bioinformatics 31:3691–3693. https://doi.org/10.1093/bioinformatics/btv421.Kaas RS, Friis C, Ussery DW, Aarestrup FM. 2012. Estimating variation within the genes and inferring the phylogeny of 186 sequenced diverse Escherichia coli genomes. BMC Genomics 13:577. https://doi.org/10.1186/1471-2164-13-577.Minkin I, Patel A, Kolmogorov M, Vyahhi N, Pham S. 2013. Sibelia: a scalable and comprehensive synteny block generation tool for closely related microbial genomes. p 215–229. In Darling A, Stoye J (ed), Lecture Notes in Computer Science vol 8126. Springer, Berlin, Germany.Jesus TF, Ribeiro-Gonçalves B, Silva DN, Bortolaia V, Ramirez M, Carriço JA. 2019. Plasmid ATLAS: plasmid visual analytics and identification in highthroughput sequencing data. Nucleic Acids Res 47:D188–D194. https://doi.org/10.1093/nar/gky1073.Arndt D, Grant JR, Marcu A, Sajed T, Pon A, Liang Y, Wishart DS. 2016. PHASTER: a better, faster version of the PHAST phage search tool. Nucleic Acids Res 44:W16–W21. https://doi.org/10.1093/nar/gkw387.Xie Z, Tang H. 2017. ISEScan: automated identification of insertion sequence elements in prokaryotic genomes. Bioinformatics 33:3340–3347. https://doi.org/10.1093/bioinformatics/btx433.Bertels F, Silander OK, Pachkov M, Rainey PB, van Nimwegen E. 2014. Automated reconstruction of whole-genome phylogenies from short-sequence reads. Mol Biol Evol 31:1077–1088. https://doi.org/10.1093/molbev/msu088.Lees JA, Harris SR, Tonkin-Hill G, Gladstone RA, Lo SW, Weiser JN, Corander J, Bentley SD, Croucher NJ. 2019. Fast and flexible bacterial genomic epidemiology with PopPUNK. Genome Res 29:304–316. https://doi.org/10.1101/gr.241455.118.Huerta-Cepas J, Szklarczyk D, Heller D, Hernández-Plaza A, Forslund SK, Cook H, Mende DR, Letunic I, Rattei T, Jensen LJ, von Mering C, Bork P. 2019. eggNOG 5.0: a hierarchical, functionally and phylogenetically annotated orthology resource based on 5090 organisms and 2 502 viruses. Nucleic Acids Res 47:D309–D314. https://doi.org/10.1093/nar/gky1085Kanehisa M, Sato Y, Morishima K. 2016. BlastKOALA and GhostKOALA: KEGG tools for functional characterization of genome and metagenome sequences. J Mol Biol 428:726–731. https://doi.org/10.1016/j.jmb.2015.11.006.Murawska E, Fiedoruk K, Bideshi DK, Swiecicka I. 2013. Complete genome sequence of Bacillus thuringiensis subsp. thuringiensis IS50056, an isolate highly toxic to Trichoplusia ni. Genome Announc 21:e0010813. https://doi.org/10.1128/genomeA.00108-13.9111
Royal Jelly Aliphatic Acids Contribute to Antimicrobial Activity of Honey
Honey is valued for its therapeutic qualities which are attributed among others to its antibacterial multifactorial properties. However, all the factors that influence these properties have not been identified. The present study is focused on the antibacterial action of fatty acids originating from royal jelly, the larval food of honeybees. Aliphatic C8-C12 acids characteristic of this bee product had previously been identified in more than fifty different samples of honey originating from seven countries and in eleven samples of Polish herbhoney. Experiments were performed to ascertain the influence of acidity on the antimicrobial activity of the acids. In acidic nutrient media all tested aliphatic hydroxyacids and unsaturated dicarboxylic acids demonstrated antibacterial action against different microbes with minimal inhibitory concentrations between 0.048 and 3.125 mM. Our results confirm that part of the antibacterial activity of honey contributes to these compounds of bee origin
Chemical Composition and Biological Activity of Argentinian Propolis of Four Species of Stingless Bees
The chemical composition of propolis of four species of stingless bees (SLBs) from Argentina was determined, and its antibacterial and anticancer activity was evaluated on selected types of microbes and cancer cell lines. Volatile secretions of all propolis samples are formed by 174 C2–C15 organic compounds, mainly mono- and sesquiterpenes and their derivatives. The chromatograms of ether extracts showed 287 peaks, of which 210 were identified. The most representative groups in the extracts of various propolis samples were diterpenoids (mainly resin acids), triterpenoids and phenolic compounds: long-chain alkenyl phenols, resorcinols and salicylates. The composition of both volatile and extractive compounds turned out to be species-specific; however, in both cases, the pairwise similarity of the propolis of Scaptotrigona postica and Tetragonisca fiebrigi versus that of Tetragona clavipes and Melipona quadrifasciata quadrifasciata was observed, which indicated the similarity of the preferences of the respective species when choosing plant sources of resin. The composition of the studied extracts completely lacked flavonoids and phenolcarboxylic acids, which are usually associated with the biological activity and medicinal properties of propolis. However, tests on selected microbial species and cancer cell lines showed such activity. All propolis samples tested against Paenibacillus larvae, two species of Bacillus and E. coli showed biofilm inhibition unrelated to the inhibition of bacterial growth, leading to a decrease in their pathogenicity. Testing the anticancer activity of ether extracts using five types of cell cultures showed that all four types of propolis studied inhibit the growth of cancer cells in a dose- and time-dependent manner. Propolis harvested by T. clavipes demonstrated the highest cytotoxicity on all tested cell lines
Melanin-like pigment production in Luria-Bertoni broth by <i>B</i>. <i>weihenstephanensis</i>.
<p><i>B</i>. <i>cereus</i> ATCC 10987 was used as the negative control.</p
PFGE fingerprints of melanin-positive <i>B</i>. <i>weihenstephanensis</i> isolates and reference strains.
<p>Genomic DNA was digested using NotI. M1, PFG Lambda Ladders; M2, PFG Yeast chromosomes. The values on the left and right are molecular weight marker in kb.</p
The phenotypic similarity and phylogeny among <i>B</i>. <i>weihenstephanensis</i> producing melanin-like pigment and reference strains.
<p>Comparisons between strains based on biochemical API 50CH and API 20E tests were made using simple matching coefficient and clustered with the UPGMA algorithm (A). Phylogenetic trees were constructed based on 16S rDNA gene (B) and seven concatenated housekeeping loci (MLST) (C) using the Neighbor-Joining (NJ) method implemented in MEGA6 software, where branch quality was evaluated using 1,000 replicates bootstraps.</p
Melanin-Like Pigment Synthesis by Soil <i>Bacillus weihenstephanensis</i> Isolates from Northeastern Poland
<div><p>Although melanin is known for protecting living organisms from harmful physical and chemical factors, its synthesis is rarely observed among endospore-forming <i>Bacillus cereus sensu lato</i>. Here, for the first time, we reported that psychrotolerant <i>Bacillus weihenstephanensis</i> from Northeastern Poland can produce melanin-like pigment. We assessed physicochemical properties of the pigment and the mechanism of its synthesis in relation to <i>B</i>. <i>weihenstephanensis</i> genotypic and phenotypic characteristics. Electron paramagnetic resonance (EPR) spectroscopy displayed a stable free radical signal of the pigment from environmental isolates which are consistent with the commercial melanin. Fourier transform infrared spectroscopy (FT-IR) and physicochemical tests indicated the phenolic character of the pigment. Several biochemical tests showed that melanin-like pigment synthesis by <i>B</i>. <i>weihenstephanensis</i> was associated with laccase activity. The presence of the gene encoding laccase was confirmed by the next generation whole genome sequencing of one <i>B</i>. <i>weihenstephanensis</i> strain. Biochemical (API 20E and 50CHB tests) and genetic (Multi-locus Sequence Typing, 16S rRNA sequencing, and Pulsed-Field Gel Electrophoresis) characterization of the isolates revealed their close relation to the psychrotrophic <i>B</i>. <i>weihenstephanensis</i> DSMZ 11821 reference strain. The ability to synthesize melanin-like pigment by soil <i>B</i>. <i>weihenstephanensis</i> isolates and their psychrotrophic character seemed to be a local adaptation to a specific niche. Detailed genetic and biochemical analyses of melanin-positive environmental <i>B</i>. <i>weihenstephanensis</i> strains shed some light on the evolution and ecological adaptation of these bacteria. Moreover, our study raised new biotechnological possibilities for the use of water-soluble melanin-like pigment naturally produced by <i>B</i>. <i>weihenstephanensis</i> as an alternative to commercial non-soluble pigment.</p></div