Life Sciences Commons^™

Francisella Tularensis Type A Strains Cause The Rapid Encystment Of Acanthamoeba Castellanii And Survive In Amoebal Cysts For Three Weeks Postinfection, Jeffrey J. Margolis, Sahar H. El-Etr, Denise Monack, Richard A. Robinson, Marissa Cohen, Emily Moore, Amy Rasley

Jeffrey Margolis

Archaeal Populations In Biological Soil Crusts From Arid Lands In North America, Tanya Soule, Ian J. Anderson, Shannon L. Johnson, Scott T. Bates, Ferran Garcia-Pichel

Tanya Soule

Archaea are common and abundant members of biological soil crust communities across large-scale biogeographic provinces of arid North America. Regardless of microbial community development, archaeal populations averaged 2 × 107 16S rRNA gene copies per gram of soil, representing around 5% of the prokaryotic (total calculated bacterial and archaeal) numbers assessed by quantitative-PCR. In contrast, archaeal diversity, determined by denaturing gradient gel electrophoresis fingerprinting and clone libraries of 16S rRNA genes, was very restricted. Only six different phylotypes (all Crenarchaea) were detected, three of which were very dominant. Some phylotypes were widespread, while others were typical of Southern desert areas.

A Comparative Genomics Approach To Understanding The Biosynthesis Of The Sunscreen Scytonemin In Cyanobacteria, Tanya Soule, Kendra Palmer, Qunjie Gao, Ruth M. Potrafka, Valerie Stout, Ferran Garcia-Pichel

Tanya Soule

Background The extracellular sunscreen scytonemin is the most common and widespread indole-alkaloid among cyanobacteria. Previous research using the cyanobacterium Nostoc punctiforme ATCC 29133 revealed a unique 18-gene cluster (NpR1276 to NpR1259 in the N. punctiforme genome) involved in the biosynthesis of scytonemin. We provide further genomic characterization of these genes in N. punctiforme and extend it to homologous regions in other cyanobacteria.

Results Six putative genes in the scytonemin gene cluster (NpR1276 to NpR1271 in the N. punctiforme genome), with no previously known protein function and annotated in this study as scyA to scyF, are likely involved in the assembly …

Identification Of Synechococcus Sp. Iu 625 Phycocyanin Gene And Bioinformatic Analyses Of Cyanobacterial Phycocyanin., Tin-Chun Chu, Aline Oliveira, Arti Rana, Lee Lee

Tin-Chun Chu, Ph.D.

No abstract provided.

Gene Expression Patterns Associated With The Biosynthesis Of The Sunscreen Scytonemin In Nostoc Punctiforme Atcc 29133 In Response To Uva Radiation, Tanya Soule, Ferran Garcia-Pichel, Valerie Stout

Tanya Soule

Under exposure to UV radiation, some cyanobacteria synthesize sunscreen compounds. Scytonemin is a heterocyclic indole-alkaloid sunscreen, the synthesis of which is induced upon exposure to UVA (long-wavelength UV) radiation. We previously identified and characterized an 18-gene cluster associated with scytonemin biosynthesis in the cyanobacterium Nostoc punctiforme ATCC 29133; we now report on the expression response of these genes to a step-up shift in UVA exposure. Using quantitative PCR on cDNAs from the N. punctiforme transcriptome and primers targeting each of the 18 genes in the cluster, we followed their differential expression in parallel subcultures incubated with and without UVA. All …

Discovery Of Dual Function Acridones As A New Antimalarial Chemotype, Jane X. Kelly, Martin J. Smilkstein, Reto Brun, Sergio Wittlin, Roland A. Cooper, Kristin D. Lane, Aaron Janowsky, Robert A. Johnson, Rozalia A. Dodean, Rolf Winter, David J. Hinrichs, Michael K. Riscoe

Roland A. Cooper

Interregional Comparison Of Karst Disturbance: West-Central Florida And Southeast Italy, Leslie North

Leslie North

Chapter 20:The Impact Of Probiotics On Maternal And Child Health: Clinical Evidence., Kingsley Anukam, Gregor Reid

Kingsley C Anukam

Key Points • Alleviating the problems of maternal and child health in countries with large malnourished and/or HIV-infected populations, will require multidimensional approaches including holistic and pharmaceutical interventions. • Urogenital infections have a major role in preterm labor and the well-being of newborns. • Probiotics show potential in reducing the risk of recurrence of urinary tract infection (UTI). • There is some evidence to suggest that probiotics can have a role to play in bacterial vaginosis (BV) and maternal health. • The role of probiotics in a number of newborn, and childhood diseases is reviewed in this chapter.

Skeletal Advance And Arrest In Giant Non-Metamorphosing African Clawed Frog Tadpoles (Xenopus Laevis: Daudin), Ryan Kerney, Richard Wassersug, Brian Hall

Ryan Kerney

This study examines the skeletons of giant non-metamorphosing (GNM) Xenopus laevis tadpoles, which arrest their development indefinitely before metamorphosis, and grow to excessively large sizes in the absence of detectable thyroid glands. Cartilage growth is isometric; however, chondrocyte size is smaller in GNM tadpoles than in controls. Most cartilages stain weakly with alcian blue, and several cartilages are calcified (unlike con- trols). However, cartilages subjacent to periosteum-derived bone retain strong affinities for alcian blue, indicat- ing a role for periosteum-derived bone in the retention of glycosaminoglycans during protracted larval growth. Bone formation in the head, limb, and axial skeletons is …

Genome-Scale Comparison And Constraint-Based Metabolic Reconstruction Of The Facilitative Anaerobic Fe(Iii)-Reducer Rhodoferax Ferrireducens, Derek Lovley, Carla Risso, Jun Sun, Kai Zhuang, Radhakrishnan Mahadevan, Robert Deboy, Wael Ismail, Susmita Shrivastava, Heather Huot, Sagar Kothari, Sean Daughtry, Olivia Bui, Christophe Schilling, Barbara Methѐ

Carla Risso

Background Rhodoferax ferrireducens is a metabolically versatile, Fe(III)-reducing, subsurface microorganism that is likely to play an important role in the carbon and metal cycles in the subsurface. It also has the unique ability to convert sugars to electricity, oxidizing the sugars to carbon dioxide with quantitative electron transfer to graphite electrodes in microbial fuel cells. In order to expand our limited knowledge about R. ferrireducens, the complete genome sequence of this organism was further annotated and then the physiology of R. ferrireducens was investigated with a constraint-based, genome-scale in silico metabolic model and laboratory studies. Results The iterative modeling and …

Contributions Of Gut Bacteria To Bacillus Thuringiensis-Induced Mortality Vary Across A Range Of Lepidoptera, Nichole A. Broderick, Courtney Jaime Robinson, Matthew D. Mcmahon, Kenneth F. Raffa

Courtney Robinson

Tracking Bacterial Responses To Global Warming With An Ecotype-Based Systematics, Frederick M. Cohan

Frederick M. Cohan

No abstract provided.

The Genome Sequence Of Geobacter Metallireducens: Features Of Metabolism, Physiology And Regulation Common And Dissimilar To Geobacter Sulfurreducens, Derek Lovley, Muktak Aklujkar, Julia Krushkal, Genevieve Dibartolo, Alla Lapidus, Miriam L. Land

Muktak Aklujkar

BACKGROUND: The genome sequence of Geobacter metallireducens is the second to be completed from the metal-respiring genus Geobacter, and is compared in this report to that of Geobacter sulfurreducens in order to understand their metabolic, physiological and regulatory similarities and differences. RESULTS: The experimentally observed greater metabolic versatility of G. metallireducens versus G. sulfurreducens is borne out by the presence of more numerous genes for metabolism of organic acids including acetate, propionate, and pyruvate. Although G. metallireducens lacks a dicarboxylic acid transporter, it has acquired a second putative succinate dehydrogenase/fumarate reductase complex, suggesting that respiration of fumarate was important until …

Impact Of An External Energy On Enterococcus Faecalis [Atcc – 51299] In Relation To Antibiotic Susceptibility And Biochemical Reactions – An Experimental Study, Mahendra Kumar Trivedi, Dr. Yogi Bhardwa, Shrikant Patil, Harish Shettigar, Archana Bulbule

Mahendra Kumar Trivedi