177 results on '"Handelsman J"'
Search Results
2. Changing the Culture of Science Education at Research Universities
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Anderson, W. A., Banerjee, U., Drennan, C. L., Elgin, S. C. R., Epstein, I. R., Handelsman, J., Hatfull, G. F., Losick, R., O'Dowd, D. K., Olivera, B. M., Strobel, S. A., Walker, G. C., and Warner, I. M.
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- 2011
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3. Use of Cluster and Discriminant Analyses to Compare Rhizosphere Bacterial Communities following Biological Perturbation
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Gilbert, G. S., Clayton, M. K., Handelsman, J., and Parke, J. L.
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- 1996
4. Scientists of the world speak up for equality
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Al-Gazali L, Moss-Racusin C, Andrei Ey, Handelsman J, Barres B, Wu La, Valian, and Husu L
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Multidisciplinary ,Sociology ,Gender gap ,Social science ,China ,Life Scientists - Abstract
Eight experts give their prescriptions for measures that will help to close the gender gap in national from China to Sweden
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- 2013
5. A 'Scientific Diversity' intervention to reduce gender bias in a sample of life scientists
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Moss-Racusin, C. A., van der Toorn, J., Dovidio, J. F., Brescoli, V. L., Graham, M. J., Handelsman, J., Social identity: Morality and diversity, Leerstoel Ellemers, Social identity: Morality and diversity, and Leerstoel Ellemers
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Adult ,Male ,media_common.quotation_subject ,education ,Sexism ,Psychological intervention ,050109 social psychology ,behavioral disciplines and activities ,Article ,Biological Science Disciplines ,General Biochemistry, Genetics and Molecular Biology ,Education ,Developmental psychology ,5. Gender equality ,Intervention (counseling) ,Humans ,0501 psychology and cognitive sciences ,Aged ,media_common ,Research ,4. Education ,05 social sciences ,050301 education ,respiratory system ,Middle Aged ,Consciousness raising ,Meritocracy ,Female ,Women in science ,Attitude change ,Faculty development ,Psychology ,human activities ,0503 education ,Diversity (politics) - Abstract
A workshop increased awareness of diversity issues, reduced gender bias, and increased readiness to take action on diversity issues from pretest (2 weeks before the intervention) to posttest (2 weeks after the intervention) among a sample of life science instructors., Mounting experimental evidence suggests that subtle gender biases favoring men contribute to the underrepresentation of women in science, technology, engineering, and mathematics (STEM), including many subfields of the life sciences. However, there are relatively few evaluations of diversity interventions designed to reduce gender biases within the STEM community. Because gender biases distort the meritocratic evaluation and advancement of students, interventions targeting instructors’ biases are particularly needed. We evaluated one such intervention, a workshop called “Scientific Diversity” that was consistent with an established framework guiding the development of diversity interventions designed to reduce biases and was administered to a sample of life science instructors (N = 126) at several sessions of the National Academies Summer Institute for Undergraduate Education held nationwide. Evidence emerged indicating the efficacy of the “Scientific Diversity” workshop, such that participants were more aware of gender bias, expressed less gender bias, and were more willing to engage in actions to reduce gender bias 2 weeks after participating in the intervention compared with 2 weeks before the intervention. Implications for diversity interventions aimed at reducing gender bias and broadening the participation of women in the life sciences are discussed.
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- 2016
6. Effect of Probiotic and Pathogenic Bacteria on Drosophila Intestinal Pathology
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Hegan, P., Mooseker, M., Handelsman, J., and Miles, J.
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Poster Abstracts - Abstract
Efforts to understand the microbial contribution to chronic conditions such as obesity, irritable bowel disease, and colon cancer have led to increased study of the human gut microbiome. With current interest in manipulating microbiome composition to treat disease, Drosophila has emerged as a model system for studying the principles that govern host-microbe interactions. We recently reported that both Drosophila-associated and human-administered probiotic strains protect Drosophila from infection. Based on these findings, we sought to use the Drosophila system to understand the effect of interactions between probiotic strains and infectious microbes on host intestinal pathology. For this work, we used entomopathogenic Serratia marcescens and the Drosophila symbiont and human probiotic Lactobacillus plantarum. To observe if L. plantarum could lessen gut damage associated with S. marcescens infection, we imaged the ultrastructure of the Drosophila gut and changes in the localization of bacterial populations during S. marcescens infection in the presence and absence of L. plantarum. We also monitored the pH of the Drosophila intestine in response to colonization with L. plantarum, challenge with S. marcescens, or both conditions. This work provides a foundation for further study of the effects of probiotic consumption on human intestinal pathology.
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- 2014
7. Archaeal and bacterial communities across a chronosequence of drained lake basins in arctic alaska
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Kao-Kniffin, J., primary, Woodcroft, B.J., additional, Carver, S.M., additional, Bockheim, J.G., additional, Handelsman, J., additional, Tyson, G.W., additional, Hinkel, K.M., additional, and Mueller, C.W., additional
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- 2015
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8. 366 days: Nature's 10
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Handelsman J, Wang J, Heuer Rd, Steltzner A, De Bernardinis B, Cynthia Rosenzweig, Cédric Blanpain, Iorns E, Fouchier R, and Gowers T
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Climate Change ,Sexism ,Mars ,Disaster Planning ,History, 21st Century ,Security Measures ,Access to Information ,Influenza, Human ,Earthquakes ,Medicine ,Animals ,Humans ,Publishing ,Multidisciplinary ,Influenza A Virus, H5N1 Subtype ,business.industry ,Physics ,Research ,Reproducibility of Results ,Genomics ,History, 20th Century ,Space Flight ,Bioterrorism ,Neoplastic Stem Cells ,New York City ,business ,Forecasting - Published
- 2012
9. Rhizobium etli CE3 Carries vir Gene Homologs on a Self-Transmissible Plasmid
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Bittinger, M. A., primary, Gross, J. A., additional, Widom, J., additional, Clardy, J., additional, and Handelsman, J., additional
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- 2000
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10. First Report of Root Rot of Soybeans Caused by Corynespora cassiicola in Wisconsin
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Raffel, S. J., primary, Kazmar, E. R., additional, Winberg, R., additional, Oplinger, E. S., additional, Handelsman, J., additional, Goodman, R. M., additional, and Grau, C. R., additional
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- 1999
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11. Genotypic and phenotypic analysis of zwittermicin A-producing strains of Bacillus cereus
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Raffel, S. J., primary, Stabb, E. V., additional, Milner, J. L., additional, and Handelsman, J., additional
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- 1996
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12. Biocontrol of Soilborne Plant Pathogens.
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Handelsman, J., primary and Stabb, E. V., additional
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- 1996
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13. Production of kanosamine by Bacillus cereus UW85
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Milner, J L, primary, Silo-Suh, L, additional, Lee, J C, additional, He, H, additional, Clardy, J, additional, and Handelsman, J, additional
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- 1996
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14. Zwittermicin A resistance gene from Bacillus cereus
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Milner, J L, primary, Stohl, E A, additional, and Handelsman, J, additional
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- 1996
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15. Zwittermicin A-producing strains of Bacillus cereus from diverse soils
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Stabb, E V, primary, Jacobson, L M, additional, and Handelsman, J, additional
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- 1994
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16. Biological activities of two fungistatic antibiotics produced by Bacillus cereus UW85
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Silo-Suh, L A, primary, Lethbridge, B J, additional, Raffel, S J, additional, He, H, additional, Clardy, J, additional, and Handelsman, J, additional
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- 1994
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17. Evaluation of a Strategy for Identifying Nodulation Competitiveness Genes in Rhizobium Leguminosarum Biovar Phaseoli
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Beattie, G. A., primary and Handelsman, J., additional
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- 1993
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18. Enhancement of soybean nodulation by Bacillus cereus UW85 in the field and in a growth chamber
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Halverson, L J, primary and Handelsman, J, additional
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- 1991
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19. Zwittermicin A biosynthetic cluster
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Stohl, E.A., Milner, J.L., and Handelsman, J.
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- 1999
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20. A vector for promoter trapping in Bacillus cereus
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Dunn, A. K. and Handelsman, J.
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- 1999
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21. Rhizobium meliloti competitiveness and the alfalfa agglutinin
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Handelsman, J, Ugalde, R A, and Brill, W J
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We have isolated two types of isolates having identical colony morphologies from stock cultures of two different Rhizobium meliloti strains. One isolate was agglutinated at a high-dilution titer (HA, highly agglutinable) of the alfalfa agglutinin and was sensitive to phage F20, and the other was agglutinated at a lower agglutinin titer (LA) and was sensitive to phage 16B. All LA isolates from the original slant produced nodules on alfalfa earlier than did HA strains from the original slant. When these HA and LA strains were mixed and used as the inoculum in both vermiculite and field soil in the laboratory, LA strains were always the predominant strains recovered from the nodules. LA strains were obtained from HA cells by selection for resistance to phage F20, and HA strains were obtained from LA cells by selection for resistance to phage 16B. All of the strains with the HA phenotype that were derived from LA strains by phage selection had the nodulation properties of the HA strains from the original slant. Two classes of strains with the LA phenotype were obtained from HA cells by phage selection. One was identical to the original LA strains from the slant, and the other had the nodulation properties of the HA strains. Thus, we have shown that some cell surface properties change the nodulation abilities of R. meliloti strains and, furthermore, that specific phages can be used to enrich for more competitive rhizobia.
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- 1984
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22. Role of galactosyltransferase activity in phage sensitivity and nodulation competitiveness of Rhizobium meliloti
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Ugalde, R A, Handelsman, J, and Brill, W J
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A stock culture of Rhizobium meliloti 102F51 contains colonies of two distinct phenotypes (Handelsman et al., J. Bacteriol. 157:703-707, 1984); one colony type is agglutinated by high dilutions of the alfalfa agglutinin, is sensitive to phage F20, and is resistant to phage 16B, and the other is agglutinated only by low dilutions of the alfalfa agglutinin, is resistant to phage F20, and is sensitive to phage 16B. Cells of the latter phenotype have an inner-membrane-bound galactosyltransferase activity that transfers galactose from UDP-galactose to a water-insoluble anionic polymer. This enzymatic activity is absent in cells of the first phenotype. All of the phage 16B-resistant mutants selected from a sensitive strain were agglutinated by high dilutions of the alfalfa agglutinin, were sensitive to phage F20, and lacked galactosyltransferase activity. The galactose-containing polymer prepared in vitro was immunologically cross-reactive with the cell surface.
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- 1986
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23. Quantitative comparison of the laboratory and field competitiveness of Rhizobium leguminosarum biovar phaseoli
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Beattie, G A, primary, Clayton, M K, additional, and Handelsman, J, additional
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- 1989
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24. Erwinia herbicola isolates from alfalfa plants may play a role in nodulation of alfalfa by Rhizobium meliloti
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Handelsman, J, primary and Brill, W J, additional
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- 1985
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25. THE SURGICAL TREATMENT AND THE PHYSIOPATHOLOGY OF COARCTATION OF THE AORTA
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Bing, R J, primary, Handelsman, J C, additional, Campbell, J A, additional, Griswold, H E, additional, and Blalock, Alfred, additional
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- 1948
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26. CHYLOUS CYSTS OF THE MESENTERY IN CHILDREN
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HANDELSMAN, J. C., primary and RAVITCH, MARK M., additional
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- 1954
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27. The orthopoedic management of myelomeningocoele
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Handelsman, J. E., primary
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- 1969
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28. Chemical modulators of the innate immune response alter gypsy moth larval susceptibility to Bacillus thuringiensis
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Broderick Nichole A, Raffa Kenneth F, and Handelsman Jo
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Microbiology ,QR1-502 - Abstract
Abstract Background The gut comprises an essential barrier that protects both invertebrate and vertebrate animals from invasion by microorganisms. Disruption of the balanced relationship between indigenous gut microbiota and their host can result in gut bacteria eliciting host responses similar to those caused by invasive pathogens. For example, ingestion of Bacillus thuringiensis by larvae of some species of susceptible Lepidoptera can result in normally benign enteric bacteria exerting pathogenic effects. Results We explored the potential role of the insect immune response in mortality caused by B. thuringiensis in conjunction with gut bacteria. Two lines of evidence support such a role. First, ingestion of B. thuringiensis by gypsy moth larvae led to the depletion of their hemocytes. Second, pharmacological agents that are known to modulate innate immune responses of invertebrates and vertebrates altered larval mortality induced by B. thuringiensis. Specifically, Gram-negative peptidoglycan pre-treated with lysozyme accelerated B. thuringiensis-induced killing of larvae previously made less susceptible due to treatment with antibiotics. Conversely, several inhibitors of the innate immune response (eicosanoid inhibitors and antioxidants) increased the host's survival time following ingestion of B. thuringiensis. Conclusions This study demonstrates that B. thuringiensis infection provokes changes in the cellular immune response of gypsy moth larvae. The effects of chemicals known to modulate the innate immune response of many invertebrates and vertebrates, including Lepidoptera, also indicate a role of this response in B. thuringiensis killing. Interactions among B. thuringiensis toxin, enteric bacteria, and aspects of the gypsy moth immune response may provide a novel model to decipher mechanisms of sepsis associated with bacteria of gut origin.
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- 2010
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29. Contributions of gut bacteria to Bacillus thuringiensis-induced mortality vary across a range of Lepidoptera
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Holt Jonathan, McMahon Matthew D, Robinson Courtney J, Broderick Nichole A, Handelsman Jo, and Raffa Kenneth F
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Biology (General) ,QH301-705.5 - Abstract
Abstract Background Gut microbiota contribute to the health of their hosts, and alterations in the composition of this microbiota can lead to disease. Previously, we demonstrated that indigenous gut bacteria were required for the insecticidal toxin of Bacillus thuringiensis to kill the gypsy moth, Lymantria dispar. B. thuringiensis and its associated insecticidal toxins are commonly used for the control of lepidopteran pests. A variety of factors associated with the insect host, B. thuringiensis strain, and environment affect the wide range of susceptibilities among Lepidoptera, but the interaction of gut bacteria with these factors is not understood. To assess the contribution of gut bacteria to B. thuringiensis susceptibility across a range of Lepidoptera we examined larval mortality of six species in the presence and absence of their indigenous gut bacteria. We then assessed the effect of feeding an enteric bacterium isolated from L. dispar on larval mortality following ingestion of B. thuringiensis toxin. Results Oral administration of antibiotics reduced larval mortality due to B. thuringiensis in five of six species tested. These included Vanessa cardui (L.), Manduca sexta (L.), Pieris rapae (L.) and Heliothis virescens (F.) treated with a formulation composed of B. thuringiensis cells and toxins (DiPel), and Lymantria dispar (L.) treated with a cell-free formulation of B. thuringiensis toxin (MVPII). Antibiotics eliminated populations of gut bacteria below detectable levels in each of the insects, with the exception of H. virescens, which did not have detectable gut bacteria prior to treatment. Oral administration of the Gram-negative Enterobacter sp. NAB3, an indigenous gut resident of L. dispar, restored larval mortality in all four of the species in which antibiotics both reduced susceptibility to B. thuringiensis and eliminated gut bacteria, but not in H. virescens. In contrast, ingestion of B. thuringiensis toxin (MVPII) following antibiotic treatment significantly increased mortality of Pectinophora gossypiella (Saunders), which was also the only species with detectable gut bacteria that lacked a Gram-negative component. Further, mortality of P. gossypiella larvae reared on diet amended with B. thuringiensis toxin and Enterobacter sp. NAB3 was generally faster than with B. thuringiensis toxin alone. Conclusion This study demonstrates that in some larval species, indigenous gut bacteria contribute to B. thuringiensis susceptibility. Moreover, the contribution of enteric bacteria to host mortality suggests that perturbations caused by toxin feeding induce otherwise benign gut bacteria to exert pathogenic effects. The interaction between B. thuringiensis and the gut microbiota of Lepidoptera may provide a useful model with which to identify the factors involved in such transitions.
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- 2009
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30. A statistical toolbox for metagenomics: assessing functional diversity in microbial communities
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Handelsman Jo and Schloss Patrick D
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Computer applications to medicine. Medical informatics ,R858-859.7 ,Biology (General) ,QH301-705.5 - Abstract
Abstract Background The 99% of bacteria in the environment that are recalcitrant to culturing have spurred the development of metagenomics, a culture-independent approach to sample and characterize microbial genomes. Massive datasets of metagenomic sequences have been accumulated, but analysis of these sequences has focused primarily on the descriptive comparison of the relative abundance of proteins that belong to specific functional categories. More robust statistical methods are needed to make inferences from metagenomic data. In this study, we developed and applied a suite of tools to describe and compare the richness, membership, and structure of microbial communities using peptide fragment sequences extracted from metagenomic sequence data. Results Application of these tools to acid mine drainage, soil, and whale fall metagenomic sequence collections revealed groups of peptide fragments with a relatively high abundance and no known function. When combined with analysis of 16S rRNA gene fragments from the same communities these tools enabled us to demonstrate that although there was no overlap in the types of 16S rRNA gene sequence observed, there was a core collection of operational protein families that was shared among the three environments. Conclusion The results of comparisons between the three habitats were surprising considering the relatively low overlap of membership and the distinctively different characteristics of the three habitats. These tools will facilitate the use of metagenomics to pursue statistically sound genome-based ecological analyses.
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- 2008
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31. GRAPHOLOGY.
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Handelsman, J. B.
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GRAPHOLOGY ,WRITING ,CALLIGRAPHY ,SIGNS & symbols ,PICTURES ,COMMUNICATION - Abstract
This article focuses on the history of the use of pictures, symbols, and calligraphy as a means of communication. Primitive people in the pre-Biblical times used pictures as a means of communication. The Greeks reversed the direction of writing from left to right and also introduced the use of abbreviation. Calligraphy was standardized for several centuries.
- Published
- 1976
32. Molecular biological access to the chemistry of unknown soil microbes: a new frontier for natural products
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Handelsman, J
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- 1998
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33. Co-zorbs: Motile, multispecies biofilms aid transport of diverse bacterial species.
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Magesh S, Schrope JH, Mercado Soto N, Li C, Hurley AI, Huttenlocher A, Beebe DJ, and Handelsman J
- Abstract
Biofilms are three-dimensional structures containing one or more bacterial species embedded in extracellular polymeric substances. Although most biofilms are stationary, Flavobacterium johnsoniae forms a motile spherical biofilm called a zorb, which is propelled by its base cells and contains a polysaccharide core. Here, we report formation of spatially organized, motile, multispecies biofilms, designated "co-zorbs," that are distinguished by a core-shell structure. F. johnsoniae forms zorbs whose cells collect other bacterial species and transport them to the zorb core, forming a co-zorb. Live imaging revealed that co-zorbs also form in zebrafish, thereby demonstrating a new type of bacterial movement in vivo. This discovery opens new avenues for understanding community behaviors, the role of biofilms in bulk bacterial transport, and collective strategies for microbial success in various environments., Significance Statement: This paper reports the discovery of co-zorbs, which are spherical aggregates of bacteria that move and transport other bacteria. Zorbs move toward other bacteria and collect them in a manner reminiscent of phagocytes. Once inside the zorb, the new species form a striking, organized core. The discovery of co-zorbs introduces an entirely new type of bacterial movement and transport involving cooperation among bacterial species. Co-zorbs have potential for engineering microbial systems for biotechnology applications and for managing spread of bacterial pathogens in their hosts.
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- 2024
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34. Massively parallel mutant selection identifies genetic determinants of Pseudomonas aeruginosa colonization of Drosophila melanogaster .
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Miles J, Lozano GL, Rajendhran J, Stabb EV, Handelsman J, and Broderick NA
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- Animals, Mice, Pseudomonas aeruginosa genetics, Genome, Bacterial, Virulence Factors genetics, Mammals genetics, Drosophila melanogaster genetics, Pseudomonas Infections genetics
- Abstract
Pseudomonas aeruginosa is recognized for its ability to colonize diverse habitats and cause disease in a variety of hosts, including plants, invertebrates, and mammals. Understanding how this bacterium is able to occupy wide-ranging niches is important for deciphering its ecology. We used transposon sequencing [Tn-Seq, also known as insertion sequencing (INSeq)] to identify genes in P. aeruginosa that contribute to fitness during the colonization of Drosophila melanogaster . Our results reveal a suite of critical factors, including those that contribute to polysaccharide production, DNA repair, metabolism, and respiration. Comparison of candidate genes with fitness determinants discovered in previous studies on P. aeruginosa identified several genes required for colonization and virulence determinants that are conserved across hosts and tissues. This analysis provides evidence for both the conservation of function of several genes across systems, as well as host-specific functions. These findings, which represent the first use of transposon sequencing of a gut pathogen in Drosophila , demonstrate the power of Tn-Seq in the fly model system and advance the existing knowledge of intestinal pathogenesis by D. melanogaster, revealing bacterial colonization determinants that contribute to a comprehensive portrait of P. aeruginosa lifestyles across habitats.IMPORTANCE Drosophila melanogaster is a powerful model for understanding host-pathogen interactions. Research with this system has yielded notable insights into mechanisms of host immunity and defense, many of which emerged from the analysis of bacterial mutants defective for well-characterized virulence factors. These foundational studies-and advances in high-throughput sequencing of transposon mutants-support unbiased screens of bacterial mutants in the fly. To investigate mechanisms of host-pathogen interplay and exploit the tractability of this model host, we used a high-throughput, genome-wide mutant analysis to find genes that enable the pathogen P. aeruginosa to colonize the fly. Our analysis reveals critical mediators of P. aeruginosa establishment in its host, some of which are required across fly and mouse systems. These findings demonstrate the utility of massively parallel mutant analysis and provide a platform for aligning the fly toolkit with comprehensive bacterial genomics., Competing Interests: The authors declare no conflict of interest.
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- 2024
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35. Surface colonization by Flavobacterium johnsoniae promotes its survival in a model microbial community.
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Magesh S, Hurley AI, Nepper JF, Chevrette MG, Schrope JH, Li C, Beebe DJ, and Handelsman J
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- Humans, Sand, Flavobacterium genetics, Bacterial Proteins metabolism, Health Promotion, Microbiota
- Abstract
Flavobacterium johnsoniae is a ubiquitous soil and rhizosphere bacterium, but despite its abundance, the factors contributing to its success in communities are poorly understood. Using a model microbial community, T he H itchhikers o f the R hizosphere (THOR), we determined the effects of colonization on the fitness of F. johnsoniae in the community. Insertion sequencing, a massively parallel transposon mutant screen, on sterile sand identified 25 genes likely to be important for surface colonization. We constructed in-frame deletions of candidate genes predicted to be involved in cell membrane biogenesis, motility, signal transduction, and transport of amino acids and lipids. All mutants poorly colonized sand, glass, and polystyrene and produced less biofilm than the wild type, indicating the importance of the targeted genes in surface colonization. Eight of the nine colonization-defective mutants were also unable to form motile biofilms or zorbs, thereby suggesting that the affected genes play a role in group movement and linking stationary and motile biofilm formation genetically. Furthermore, we showed that the deletion of colonization genes in F. johnsoniae affected its behavior and survival in THOR on surfaces, suggesting that the same traits are required for success in a multispecies microbial community. Our results provide insight into the mechanisms of surface colonization by F. johnsoniae and form the basis for further understanding its ecology in the rhizosphere., Importance: Microbial communities direct key environmental processes through multispecies interactions. Understanding these interactions is vital for manipulating microbiomes to promote health in human, environmental, and agricultural systems. However, microbiome complexity can hinder our understanding of the underlying mechanisms in microbial community interactions. As a first step toward unraveling these interactions, we explored the role of surface colonization in microbial community interactions using T he H itchhikers O f the R hizosphere (THOR), a genetically tractable model community of three bacterial species, Flavobacterium johnsoniae , Pseudomonas koreensis , and Bacillus cereus . We identified F. johnsoniae genes important for surface colonization in solitary conditions and in the THOR community. Understanding the mechanisms that promote the success of bacteria in microbial communities brings us closer to targeted manipulations to achieve outcomes that benefit agriculture, the environment, and human health., Competing Interests: David J. Beebe holds equity in Bellbrook Labs LLC, Tasso Inc., Salus Discovery LLC, Lynx Biosciences Inc., Stacks to the Future LLC, Flambeau Diagnostics LLC, and Onexio Biosystems LLC. Jo Handelsman holds equity in Wacasa Inc. and Ascribe, Inc.
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- 2024
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36. Microbiome composition modulates secondary metabolism in a multispecies bacterial community.
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Chevrette MG, Thomas CS, Hurley A, Rosario-Meléndez N, Sankaran K, Tu Y, Hall A, Magesh S, and Handelsman J
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- Anti-Bacterial Agents, Benzamides, Humans, Secondary Metabolism, Microbiota, Siderophores genetics, Siderophores metabolism
- Abstract
Bacterial secondary metabolites are a major source of antibiotics and other bioactive compounds. In microbial communities, these molecules can mediate interspecies interactions and responses to environmental change. Despite the importance of secondary metabolites in human health and microbial ecology, little is known about their roles and regulation in the context of multispecies communities. In a simplified model of the rhizosphere composed of Bacillus cereus , Flavobacterium johnsoniae , and Pseudomonas koreensis , we show that the dynamics of secondary metabolism depend on community species composition and interspecies interactions. Comparative metatranscriptomics and metametabolomics reveal that the abundance of transcripts of biosynthetic gene clusters (BGCs) and metabolomic molecular features differ between monocultures or dual cultures and a tripartite community. In both two- and three-member cocultures, P. koreensis modified expression of BGCs for zwittermicin, petrobactin, and other secondary metabolites in B. cereus and F. johnsoniae, whereas the BGC transcriptional response to the community in P. koreensis itself was minimal. Pairwise and tripartite cocultures with P. koreensis displayed unique molecular features that appear to be derivatives of lokisin, suggesting metabolic handoffs between species. Deleting the BGC for koreenceine, another P. koreensis metabolite, altered transcript and metabolite profiles across the community, including substantial up-regulation of the petrobactin and bacillibactin BGCs in B. cereus , suggesting that koreenceine represses siderophore production. Results from this model community show that bacterial BGC expression and chemical output depend on the identity and biosynthetic capacity of coculture partners, suggesting community composition and microbiome interactions may shape the regulation of secondary metabolism in nature.
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- 2022
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37. THOR's Hammer: the Antibiotic Koreenceine Drives Gene Expression in a Model Microbial Community.
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Hurley A, Chevrette MG, Rosario-Meléndez N, and Handelsman J
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- Gene Expression, Humans, Pseudomonas, Rhizosphere, Anti-Bacterial Agents pharmacology, Microbiota
- Abstract
Microbial interactions dictate the structure and function of microbiomes, but the complexity of natural communities can obscure the individual interactions. Model microbial communities constructed with genetically tractable strains known to interact in natural settings can untangle these networks and reveal underpinning mechanisms. Our model system, T he H itchhikers o f the R hizosphere (THOR), is composed of three species-Bacillus cereus, Flavobacterium johnsoniae, and Pseudomonas koreensis-that co-isolate from field-grown soybean roots. Comparative metatranscriptomics on THOR revealed global patterns of interspecies transcriptional regulation. When grown in pairs, each member of THOR exhibits unique signaling behavior. In the community setting, gene expression is dominated by pairwise interactions with Pseudomonas koreensis mediated either directly or indirectly by its production of the antibiotic koreenceine-the apparent "hammer" of THOR. In pairwise interactions, the koreenceine biosynthetic cluster is responsible for 85 and 22% of differentially regulated genes in F. johnsoniae and B. cereus, respectively. Although both deletion of the koreenceine locus and reduction of P. koreensis inoculum size increase F. johnsoniae populations, the transcriptional response of P. koreensis is only activated when it is a relative minority member at the beginning of coculture. The largest group of upregulated P. koreensis genes in response to F. johnsoniae are those without functional annotation, indicating that focusing on genes important for community interactions may offer a path toward functional assignments for unannotated genes. This study illustrates the power of comparative metatranscriptomics of microorganisms encountering increasing microbial complexity for understanding community signal integration, antibiotic responses, and interspecies communication. IMPORTANCE The diversity, ubiquity, and significance of microbial communities is clear. However, the predictable and reliable manipulation of microbiomes to impact human, environmental, and agricultural health remains a challenge. Effective remodeling of microbiomes will be enabled by understanding the interspecies interactions that govern community processes. The extreme complexity of most microbiomes has impeded characterization of the relevant interactions. Investigating the genetics and biochemistry of simplified, model microbiomes could unearth specific interactions and generate predictions about community-governing principles. Here, we use one such model community to quantify changes in gene expression of individual species as they encounter stimuli from one or more species, directly mapping combinatorial interspecies interactions. A surprising amount of gene expression is regulated by a single molecule, the antibiotic koreenceine, which appears to impact gene regulation across community networks.
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- 2022
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38. Public engagement: Faculty lived experiences and perspectives underscore barriers and a changing culture in academia.
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Calice MN, Beets B, Bao L, Scheufele DA, Freiling I, Brossard D, Feinstein NW, Heisler L, Tangen T, and Handelsman J
- Subjects
- Financing, Organized, Humans, Organizations, United States, Universities, Faculty, Students
- Abstract
The idea of faculty engaging in meaningful dialogue with different publics instead of simply communicating their research to interested audiences has gradually morphed from a novel concept to a mainstay within most parts of the academy. Given the wide variety of public engagement modalities, it may be unsurprising that we still lack a comprehensive and granular understanding of factors that influence faculty willingness to engage with public audiences. Those nuances are not always captured by quantitative surveys that rely on pre-determined categories to assess scholars' willingness to engage. While closed-ended categories are useful to examine which factors influence the willingness to engage more than others, it is unlikely that pre-determined categories comprehensively represent the range of factors that undermine or encourage engagement, including perceptual influences, institutional barriers, and scholars' lived experiences. To gain insight into these individual perspectives and lived experiences, we conducted focus group discussions with faculty members at a large midwestern land-grant university in the United States. Our findings provide context to previous studies of public engagement and suggest four themes for future research. These themes affirm the persistence of institutional barriers to engaging with the public, particularly the expectations in the promotion process for tenure-track faculty. However, we also find a perception that junior faculty and graduate students are challenging the status quo by introducing a new wave of attention to public engagement. This finding suggests a "trickle-up" effect through junior faculty and graduate students expecting institutional support for public engagement. Our findings highlight the need to consider how both top-down factors such as institutional expectations and bottom-up factors such as graduate student interest shape faculty members' decisions to participate in public engagement activities., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2022
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39. AJEDI in Science: Leveraging Instructor Communities to Create Antiracist Curricula.
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Miller S, Kerr JE, and Handelsman J
- Abstract
Gateway college science courses continue to exclude students from science, disproportionately discriminating against students of color. As the higher education system strives to reduce discrimination, we need a deliberate, iterative process to modify, supplement, or replace current modalities. By incorporating antiracist, just, equitable, diverse, and inclusive (AJEDI) principles throughout course design, instructors create learning environments that provide an antidote to historically oppressive systems. In this paper, we describe how a community of microbiology instructors who all teach Tiny Earth, a course-based undergraduate research experience, created and rapidly integrated antiracist content and pivoted to an online format in response to the social unrest and pandemic of 2020. The effort strengthened an existing teaching community of practice and produced collective change in classrooms across the nation. We provide a perspective on how instructor communities of practice can be leveraged to design and disseminate AJEDI curriculum., Competing Interests: The authors declare a conflict of interest. J.H. is part owner of Wacasa, Inc., a start-up dedicated to antibiotic discovery., (Copyright © 2022 Miller et al.)
- Published
- 2022
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40. Social motility of biofilm-like microcolonies in a gliding bacterium.
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Li C, Hurley A, Hu W, Warrick JW, Lozano GL, Ayuso JM, Pan W, Handelsman J, and Beebe DJ
- Subjects
- Computer Simulation, Intravital Microscopy, Microfluidic Analytical Techniques, Plant Roots microbiology, Soil Microbiology, Time-Lapse Imaging, Biofilms, Flavobacterium physiology, Locomotion
- Abstract
Bacterial biofilms are aggregates of surface-associated cells embedded in an extracellular polysaccharide (EPS) matrix, and are typically stationary. Studies of bacterial collective movement have largely focused on swarming motility mediated by flagella or pili, in the absence of a biofilm. Here, we describe a unique mode of collective movement by a self-propelled, surface-associated biofilm-like multicellular structure. Flavobacterium johnsoniae cells, which move by gliding motility, self-assemble into spherical microcolonies with EPS cores when observed by an under-oil open microfluidic system. Small microcolonies merge, creating larger ones. Microscopic analysis and computer simulation indicate that microcolonies move by cells at the base of the structure, attached to the surface by one pole of the cell. Biochemical and mutant analyses show that an active process drives microcolony self-assembly and motility, which depend on the bacterial gliding apparatus. We hypothesize that this mode of collective bacterial movement on solid surfaces may play potential roles in biofilm dynamics, bacterial cargo transport, or microbial adaptation. However, whether this collective motility occurs on plant roots or soil particles, the native environment for F. johnsoniae, is unknown., (© 2021. The Author(s).)
- Published
- 2021
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41. Tiny Earth: A Big Idea for STEM Education and Antibiotic Discovery.
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Hurley A, Chevrette MG, Acharya DD, Lozano GL, Garavito M, Heinritz J, Balderrama L, Beebe M, DenHartog ML, Corinaldi K, Engels R, Gutierrez A, Jona O, Putnam JHI, Rhodes B, Tsang T, Hernandez S, Bascom-Slack C, Blum JE, Price PA, Davis D, Klein J, Pultorak J, Sullivan NL, Mouncey NJ, Dorrestein PC, Miller S, Broderick NA, and Handelsman J
- Subjects
- Bacteria drug effects, Drug Discovery methods, Humans, Anti-Bacterial Agents, Drug Discovery education, Science education, Students
- Abstract
The world faces two seemingly unrelated challenges-a shortfall in the STEM workforce and increasing antibiotic resistance among bacterial pathogens. We address these two challenges with Tiny Earth, an undergraduate research course that excites students about science and creates a pipeline for antibiotic discovery., (Copyright © 2021 Hurley et al.)
- Published
- 2021
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42. A Chemical Counterpunch: Chromobacterium violaceum ATCC 31532 Produces Violacein in Response to Translation-Inhibiting Antibiotics.
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Lozano GL, Guan C, Cao Y, Borlee BR, Broderick NA, Stabb EV, and Handelsman J
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- Animals, Biofilms drug effects, Biofilms growth & development, Chromobacterium genetics, Chromobacterium pathogenicity, Drosophila melanogaster, Female, Gene Expression Regulation, Bacterial, Hygromycin B pharmacology, Quorum Sensing drug effects, Streptomyces metabolism, Virulence, Anti-Bacterial Agents pharmacology, Antibiosis drug effects, Chromobacterium drug effects, Cinnamates pharmacology, Hygromycin B analogs & derivatives, Indoles metabolism, Protein Biosynthesis drug effects
- Abstract
Antibiotics produced by bacteria play important roles in microbial interactions and competition Antibiosis can induce resistance mechanisms in target organisms, and at sublethal doses, antibiotics have been shown to globally alter gene expression patterns. Here, we show that hygromycin A from Streptomyces sp. strain 2AW. induces Chromobacterium violaceum ATCC 31532 to produce the purple antibiotic violacein. Sublethal doses of other antibiotics that similarly target the polypeptide elongation step of translation likewise induced violacein production, unlike antibiotics with different targets. C. violaceum biofilm formation and virulence against Drosophila melanogaster were also induced by translation-inhibiting antibiotics, and we identified an a ntibiotic- i nduced r esponse ( air ) two-component regulatory system that is required for these responses. Genetic analyses indicated a connection between the Air system, quorum-dependent signaling, and the negative regulator VioS, leading us to propose a model for induction of violacein production. This work suggests a novel mechanism of interspecies interaction in which a bacterium produces an antibiotic in response to inhibition by another bacterium and supports the role of antibiotics as signal molecules. IMPORTANCE Secondary metabolites play important roles in microbial communities, but their natural functions are often unknown and may be more complex than appreciated. While compounds with antibiotic activity are often assumed to underlie microbial competition, they may alternatively act as signal molecules. In either scenario, microorganisms might evolve responses to sublethal concentrations of these metabolites, either to protect themselves from inhibition or to change certain behaviors in response to the local abundance of another species. Here, we report that violacein production by C. violaceum ATCC 31532 is induced in response to hygromycin A from Streptomyces sp. 2AW, and we show that this response is dependent on inhibition of translational polypeptide elongation and a previously uncharacterized two-component regulatory system. The breadth of the transcriptional response beyond violacein induction suggests a surprisingly complex metabolite-mediated microbe-microbe interaction and supports the hypothesis that antibiotics evolved as signal molecules. These novel insights will inform predictive models of soil community dynamics and the unintended effects of clinical antibiotic administration., (Copyright © 2020 Lozano et al.)
- Published
- 2020
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43. Design and validation of a transposon that promotes expression of genes in episomal DNA.
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Mongui A, Lozano GL, Handelsman J, Restrepo S, and Junca H
- Subjects
- DNA-Directed RNA Polymerases biosynthesis, Escherichia coli metabolism, Plasmids metabolism, Viral Proteins biosynthesis, DNA Transposable Elements, DNA-Directed RNA Polymerases genetics, Escherichia coli genetics, Gene Expression, Plasmids genetics, Promoter Regions, Genetic, Viral Proteins genetics
- Abstract
Functional metagenomics, or the cloning and expression of DNA isolated directly from environmental samples, represents a source of novel compounds with biotechnological potential. However, attempts to identify such compounds in metagenomic libraries are generally inefficient in part due to lack of expression of heterologous DNA. In this research, the TnC_T7 transposon was developed to supply transcriptional machinery during functional analysis of metagenomic libraries. TnC_T7 contains bidirectional T7 promoters, the gene encoding the T7 RNA polymerase (T7RNAP), and a kanamycin resistance gene. The T7 RNA polymerase gene is regulated by the inducible arabinose promoter (P
BAD ), thereby facilitating inducible expression of genes adjacent to the randomly integrating transposon. The high processivity of T7RNAP should make this tool particularly useful for obtaining gene expression in long inserts. TnC_T7 functionality was validated by conducting in vitro transposition of pKR-C12 or fosmid pF076_GFPmut3*, carrying metagenomic DNA from soil. We identified transposon insertions that enhanced GFP expression in both vectors, including insertions in which the promoter delivered by the transposon was located as far as 8.7 kb from the GFP gene, indicating the power of the high processivity of the T7 polymerase. The results gathered in this research demonstrate the potential of TnC_T7 to enhance gene expression in functional metagenomic studies., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)- Published
- 2020
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44. Bacterial Analogs of Plant Tetrahydropyridine Alkaloids Mediate Microbial Interactions in a Rhizosphere Model System.
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Lozano GL, Park HB, Bravo JI, Armstrong EA, Denu JM, Stabb EV, Broderick NA, Crawford JM, and Handelsman J
- Subjects
- Microbial Interactions, Soil Microbiology, Alkaloids metabolism, Flavobacterium growth & development, Pseudomonas physiology, Pyrrolidines metabolism, Rhizosphere
- Abstract
Plants expend significant resources to select and maintain rhizosphere communities that benefit their growth and protect them from pathogens. A better understanding of assembly and function of rhizosphere microbial communities will provide new avenues for improving crop production. Secretion of antibiotics is one means by which bacteria interact with neighboring microbes and sometimes change community composition. In our analysis of a taxonomically diverse consortium from the soybean rhizosphere, we found that Pseudomonas koreensis selectively inhibits growth of Flavobacterium johnsoniae and other members of the Bacteroidetes grown in soybean root exudate. A genetic screen in P. koreensis identified a previously uncharacterized biosynthetic gene cluster responsible for the inhibitory activity. Metabolites were isolated based on biological activity and were characterized using tandem mass spectrometry, multidimensional nuclear magnetic resonance, and Mosher ester analysis, leading to the discovery of a new family of bacterial tetrahydropyridine alkaloids, koreenceine A to D (metabolites 1 to 4). Three of these metabolites are analogs of the plant alkaloid γ-coniceine. Comparative analysis of the koreenceine cluster with the γ-coniceine pathway revealed distinct polyketide synthase routes to the defining tetrahydropyridine scaffold, suggesting convergent evolution. Koreenceine-type pathways are widely distributed among Pseudomonas species, and koreenceine C was detected in another Pseudomonas species from a distantly related cluster. This work suggests that Pseudomonas and plants convergently evolved the ability to produce similar alkaloid metabolites that can mediate interbacterial competition in the rhizosphere. IMPORTANCE The microbiomes of plants are critical to host physiology and development. Microbes are attracted to the rhizosphere due to massive secretion of plant photosynthates from roots. Microorganisms that successfully join the rhizosphere community from bulk soil have access to more abundant and diverse molecules, producing a highly competitive and selective environment. In the rhizosphere, as in other microbiomes, little is known about the genetic basis for individual species' behaviors within the community. In this study, we characterized competition between Pseudomonas koreensis and Flavobacterium johnsoniae , two common rhizosphere inhabitants. We identified a widespread gene cluster in several Pseudomonas spp. that is necessary for the production of a novel family of tetrahydropyridine alkaloids that are structural analogs of plant alkaloids. We expand the known repertoire of antibiotics produced by Pseudomonas in the rhizosphere and demonstrate the role of the metabolites in interactions with other rhizosphere bacteria., (Copyright © 2019 Lozano et al.)
- Published
- 2019
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45. Evaluation of INSeq To Identify Genes Essential for Pseudomonas aeruginosa PGPR2 Corn Root Colonization.
- Author
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Sivakumar R, Ranjani J, Vishnu US, Jayashree S, Lozano GL, Miles J, Broderick NA, Guan C, Gunasekaran P, Handelsman J, and Rajendhran J
- Subjects
- Bacterial Proteins metabolism, High-Throughput Nucleotide Sequencing, Molecular Sequence Annotation, Mutagenesis, Insertional, Plant Roots microbiology, Plant Roots physiology, Pseudomonas aeruginosa metabolism, Pseudomonas aeruginosa physiology, Zea mays physiology, Genes, Bacterial, Pseudomonas aeruginosa genetics, Symbiosis, Zea mays microbiology
- Abstract
The reciprocal interaction between rhizosphere bacteria and their plant hosts results in a complex battery of genetic and physiological responses. In this study, we used insertion sequencing (INSeq) to reveal the genetic determinants responsible for the fitness of Pseudomonas aeruginosa PGPR2 during root colonization. We generated a random transposon mutant library of Pseudomonas aeruginosa PGPR2 comprising 39,500 unique insertions and identified genes required for growth in culture and on corn roots. A total of 108 genes were identified as contributing to the fitness of strain PGPR2 on roots. The importance in root colonization of four genes identified in the INSeq screen was verified by constructing deletion mutants in the genes and testing them for the ability to colonize corn roots singly or in competition with the wild type. All four mutants were affected in corn root colonization, displaying 5- to 100-fold reductions in populations in single inoculations, and all were outcompeted by the wild type by almost 100-fold after seven days on corn roots in mixed inoculations of the wild type and mutant. The genes identified in the screen had homology to genes involved in amino acid catabolism, stress adaptation, detoxification, signal transduction, and transport. INSeq technology proved a successful tool to identify fitness factors in P aeruginosa PGPR2 for root colonization., (Copyright © 2019 Sivakumar et al.)
- Published
- 2019
- Full Text
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46. Introducing THOR, a Model Microbiome for Genetic Dissection of Community Behavior.
- Author
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Lozano GL, Bravo JI, Garavito Diago MF, Park HB, Hurley A, Peterson SB, Stabb EV, Crawford JM, Broderick NA, and Handelsman J
- Subjects
- Bacteroidetes, Firmicutes growth & development, Models, Biological, Proteobacteria growth & development, Rhizosphere, Firmicutes physiology, Microbial Interactions, Microbiota, Proteobacteria physiology, Soil Microbiology
- Abstract
The quest to manipulate microbiomes has intensified, but many microbial communities have proven to be recalcitrant to sustained change. Developing model communities amenable to genetic dissection will underpin successful strategies for shaping microbiomes by advancing an understanding of community interactions. We developed a model community with representatives from three dominant rhizosphere taxa, the Firmicutes , Proteobacteria , and Bacteroidetes We chose Bacillus cereus as a model rhizosphere firmicute and characterized 20 other candidates, including "hitchhikers" that coisolated with B. cereus from the rhizosphere. Pairwise analysis produced a hierarchical interstrain-competition network. We chose two hitchhikers, Pseudomonas koreensis from the top tier of the competition network and Flavobacterium johnsoniae from the bottom of the network, to represent the Proteobacteria and Bacteroidetes , respectively. The model community has several emergent properties, induction of dendritic expansion of B. cereus colonies by either of the other members, and production of more robust biofilms by the three members together than individually. Moreover, P. koreensis produces a novel family of alkaloid antibiotics that inhibit growth of F. johnsoniae , and production is inhibited by B. cereus We designate this community THOR, because the members are t he h itchhikers o f the r hizosphere. The genetic, genomic, and biochemical tools available for dissection of THOR provide the means to achieve a new level of understanding of microbial community behavior. IMPORTANCE The manipulation and engineering of microbiomes could lead to improved human health, environmental sustainability, and agricultural productivity. However, microbiomes have proven difficult to alter in predictable ways, and their emergent properties are poorly understood. The history of biology has demonstrated the power of model systems to understand complex problems such as gene expression or development. Therefore, a defined and genetically tractable model community would be useful to dissect microbiome assembly, maintenance, and processes. We have developed a tractable model rhizosphere microbiome, designated THOR, containing Pseudomonas koreensis , Flavobacterium johnsoniae , and Bacillus cereus , which represent three dominant phyla in the rhizosphere, as well as in soil and the mammalian gut. The model community demonstrates emergent properties, and the members are amenable to genetic dissection. We propose that THOR will be a useful model for investigations of community-level interactions., (Copyright © 2019 Lozano et al.)
- Published
- 2019
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47. Crystal structure and kinetic analysis of the class B3 di-zinc metallo-β-lactamase LRA-12 from an Alaskan soil metagenome.
- Author
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Rodríguez MM, Herman R, Ghiglione B, Kerff F, D'Amico González G, Bouillenne F, Galleni M, Handelsman J, Charlier P, Gutkind G, Sauvage E, and Power P
- Subjects
- Alaska, Amino Acid Sequence, Bacterial Proteins metabolism, Biocatalysis drug effects, Catalytic Domain, Chelating Agents pharmacology, Crystallography, X-Ray, Drug Resistance, Bacterial drug effects, Edetic Acid pharmacology, Escherichia coli drug effects, Kinetics, Microbial Sensitivity Tests, Models, Molecular, Phenotype, Sequence Analysis, Protein, beta-Lactamases metabolism, Metagenome, Soil, Zinc metabolism, beta-Lactamases chemistry
- Abstract
We analyzed the kinetic properties of the metagenomic class B3 β-lactamase LRA-12, and determined its crystallographic structure in order to compare it with prevalent metallo-β-lactamases (MBLs) associated with clinical pathogens. We showed that LRA-12 confers extended-spectrum resistance on E. coli when expressed from recombinant clones, and the MIC values for carbapenems were similar to those observed in enterobacteria expressing plasmid-borne MBLs such as VIM, IMP or NDM. This was in agreement with the strong carbapenemase activity displayed by LRA-12, similar to GOB β-lactamases. Among the chelating agents evaluated, dipicolinic acid inhibited the enzyme more strongly than EDTA, which required pre-incubation with the enzyme to achieve measurable inhibition. Structurally, LRA-12 contains the conserved main structural features of di-zinc class B β-lactamases, and presents unique structural signatures that differentiate this enzyme from others within the family: (i) two loops (α3-β7 and β11-α5) that could influence antibiotic entrance and remodeling of the active site cavity; (ii) a voluminous catalytic cavity probably responsible for the high hydrolytic efficiency of the enzyme; (iii) the absence of disulfide bridges; (iv) a unique Gln116 at metal-binding site 1; (v) a methionine residue at position 221that replaces Cys/Ser found in other B3 β-lactamases in a predominantly hydrophobic environment, likely playing a role in protein stability. The structure of LRA-12 indicates that MBLs exist in wild microbial populations in extreme environments, or environments with low anthropic impact, and under the appropriate antibiotic selective pressure could be captured and disseminated to pathogens.
- Published
- 2017
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48. Draft Genome Sequence of Pseudomonas koreensis CI12, a Bacillus cereus "Hitchhiker" from the Soybean Rhizosphere.
- Author
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Lozano GL, Bravo JI, and Handelsman J
- Abstract
Pseudomonas koreensis CI12 was coisolated with Bacillus cereus from a root of a soybean plant grown in a field in Arlington, WI. Here, we report the draft genome sequence of P. koreensis CI12 obtained by Illumina sequencing., (Copyright © 2017 Lozano et al.)
- Published
- 2017
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49. Draft Genome Sequence of Flavobacterium johnsoniae CI04, an Isolate from the Soybean Rhizosphere.
- Author
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Bravo JI, Lozano GL, and Handelsman J
- Abstract
Flavobacterium johnsoniae CI04 was coisolated with Bacillus cereus from a root of a field-grown soybean plant in Arlington, WI, and selected as a model for studying commensalism between members of the Cytophaga-Flavobacterium-Bacteroides group and B. cereus Here we report the draft genome sequence of F. johnsoniae CI04 obtained by Illumina sequencing., (Copyright © 2017 Bravo et al.)
- Published
- 2017
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50. Metabolite exchange between microbiome members produces compounds that influence Drosophila behavior.
- Author
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Fischer CN, Trautman EP, Crawford JM, Stabb EV, Handelsman J, and Broderick NA
- Subjects
- Acetic Acid metabolism, Animals, Ethanol metabolism, Volatile Organic Compounds metabolism, Acetobacter metabolism, Behavior, Animal drug effects, Drosophila melanogaster drug effects, Drosophila melanogaster physiology, Microbiota, Saccharomyces metabolism
- Abstract
Animals host multi-species microbial communities (microbiomes) whose properties may result from inter-species interactions; however, current understanding of host-microbiome interactions derives mostly from studies in which elucidation of microbe-microbe interactions is difficult. In exploring how Drosophila melanogaster acquires its microbiome, we found that a microbial community influences Drosophila olfactory and egg-laying behaviors differently than individual members. Drosophila prefers a Saccharomyces - Acetobacter co-culture to the same microorganisms grown individually and then mixed, a response mainly due to the conserved olfactory receptor, Or42b. Acetobacter metabolism of Saccharomyces- derived ethanol was necessary, and acetate and its metabolic derivatives were sufficient, for co-culture preference. Preference correlated with three emergent co-culture properties: ethanol catabolism, a distinct volatile profile, and yeast population decline. Egg-laying preference provided a context-dependent fitness benefit to larvae. We describe a molecular mechanism by which a microbial community affects animal behavior. Our results support a model whereby emergent metabolites signal a beneficial multispecies microbiome., Competing Interests: The authors declare that no competing interests exist.
- Published
- 2017
- Full Text
- View/download PDF
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