Life Sciences Commons^™

A Diverse Assemblage Of Indole-3-Acetic Acid Producing Bacteria Associate With Unicellular Green Algae, Christopher Bagwell, Magdalena Piskorska, Tanya Soule, Angela Petelos, Christopher Yeager

Tanya Soule

Microalgae have tremendous potential as a renewable feedstock for the production of liquid transportation fuels. In natural waters, the importance of physical associations and biochemical interactions between microalgae and bacteria is generally well appreciated, but the significance of these interactions to algal biofuels production have not been investigated. Here, we provide a preliminary report on the frequency of co-occurrence between indole-3-acetic acid (IAA)-producing bacteria and green algae in natural and engineered ecosystems. Growth experiments with unicellular algae, Chlorella and Scenedesmus, revealed IAA concentration-dependent responses in chlorophyll content and dry weight. Importantly, discrete concentrations of IAA resulted in cell culture synchronization, …

Microbial Isolations From Olive Ridley (Lepidochelys Olivacea) And Eastern Pacific Green (Chelonia Mydas Agassizii) Sea Turtle Nests In Guanacaste, Costa Rica, And Standard Testing Of Cloacal Fluid Antimicrobial Properties, Erin Keene, Tanya Soule, Frank Paladino

Tanya Soule

Microorganisms associated with olive ridley and East Pacific green turtle nesting and potential cloacal fluid antimicrobial properties were studied in Guanacaste, Costa Rica. During the 2010–2011 season, bacteria and fungi were isolated from olive ridley cloacal fluid, nest chamber sand, and egg samples. Because of the lack of cloacal fluid bacteria isolated, the focus of the 2011–2012 season shifted to determine whether fluid contained antibacterial properties by using Kirby–Bauer disk diffusion assays, and cloacal fluid and sand samples were taken to see whether bacteria were unique to cloacal fluid. Assays were performed on 34 olive ridley and 5 East Pacific …

Ultraviolet Photoprotective Compounds From Cyanobacteria In Biomedical Applications, Tanya Soule, Ferran Garcia-Pichel

Tanya Soule

No abstract provided.

Transcriptional Regulation Of Sunscreen Biosynthesis In Cyanobacteria, Tanya Soule

Tanya Soule

No abstract provided.

The Global Response Of Nostoc Punctiforme Atcc 29133 To Uva Stress, Assessed In A Temporal Dna Microarray Study, Tanya Soule, Qunjie Gao, Valerie Stout, Ferran Garcia-Pichel

Tanya Soule

Cyanobacteria in nature are exposed not only to the visible spectrum of sunlight but also to its harmful ultraviolet components (UVA and UVB). We used Nostoc punctiforme ATCC 29133 as a model to study the UVA response by analyzing global gene expression patterns using genomic microarrays. UVA exposure resulted in the statistically detectable differential expression of 573 genes of the 6903 that were probed, compared with that of the control cultures. Of those genes, 473 were up-regulated, while only 100 were down-regulated. Many of the down-regulated genes were involved in photosynthetic pigment biosynthesis, indicating a significant shift in this metabolism. …

The Use Of Course Response Systems To Assess Student Learning In The Classroom, Tanya Soule, Jordan Marshall

Tanya Soule

No abstract provided.

Ammonia-Oxidizing Archaea And Bacteria Are Structured By Geography In Biological Soil Crusts Across North America, Yevgeniy Marusenko, Scott Bates, Ian Anderson, Shannon Johnson, Tanya Soule, Ferran Garcia-Pichel

Tanya Soule

Introduction Biological soil crusts (BSCs) can dominate surface cover in dry lands worldwide, playing an integral role in arid land biogeochemistry, particularly in N fertilization through fixation and cycling. Nitrification is a characteristic and universal N transformation in BSCs that becomes important for the export of N beyond the microscopic bounds of the crust itself. The contribution of ammonia-oxidizing bacteria (AOB) in BSCs has been shown, but the role and extent of the recently discovered ammonia-oxidizing archaea (AOA) have not.

Methods We sampled various types of crusts in four desert regions across the western United States and characterized the composition …

Preservation Of H2 Production Activity In Nanoporous Latex Coatings Of Rhodopseudomonas Palustris Cga009 During Dry Storage At Ambient Temperatures, Magdalena Piskorska, Tanya Soule, J Gosse, C Milliken, M Flickinger, G Smith, C Yeager

Tanya Soule

To assess the applicability of latex cell coatings as an ‘off-the-shelf’ biocatalyst, the effect of osmoprotectants, temperature, humidity and O2 on preservation of H2 production in Rhodopseudomonas palustris coatings was evaluated. Immediately following latex coating coalescence (24 h) and for up to 2 weeks of dry storage, rehydrated coatings containing different osmoprotectants displayed similar rates of H2 production. Beyond 2 weeks of storage, sorbitol-treated coatings lost all H2 production activity, whereas considerable H2 production was still detected in sucrose- and trehalose-stabilized coatings. The relative humidity level at which the coatings were stored had a significant impact on the recovery and …

Microbial Sunscreens: Opportunities And Obstacles, Tanya Soule

Tanya Soule

No abstract provided.

Accumulation Of Extracellular Carbohydrates In A Scytonemin-Deficient Mutant Of Nostoc Punctiforme Exposed To Uva Stress, Tanya Soule

Tanya Soule

No abstract provided.

Bacteria And Fungi Cultured From Sand, Cloacal Fluids, And Unhatched Eggs Of Olive Ridley Sea Turtles And Standard Testing Of Antimicrobial Properties Of Cloacal Fluids, Erin Keene, Tanya Soule, Frank Paladino

Tanya Soule

No abstract provided.

Investigation Of The Relationship Between Extracellular Slime Layer And Sunscreen Production In Nostoc Punctiforme, Pavan Paten, Dexter Shipe, Tanya Soule

Tanya Soule

No abstract provided.

Bacteria And Fungi Cultured From Sand, Cloacal Fluids, And Unhatched Eggs Of Olive Ridley Sea Turtles And Standard Testing Of Antimicrobial Properties Of Cloacal Fluids, Erin Keene, Tanya Soule, Frank Paladino

Tanya Soule

No abstract provided.

Sunscreen Biosynthesis In Cyanobacteria, Tanya Soule

Tanya Soule

No abstract provided.

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 …

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 …

Molecular Genetics And Genomic Analysis Of Scytonemin Biosynthesis In Nostoc Punctiforme Atcc 29133, Tanya Soule, Valerie Stout, Wesley Swingley, J C. Meeks, Ferran Garcia-Pichel

Tanya Soule

The indole-alkaloid scytonemin is the most common and widespread sunscreen among cyanobacteria. Previous research has focused on its nature, distribution, ecology, physiology, and biochemistry, but its molecular genetics have not been explored. In this study, a scytonemin-deficient mutant of the cyanobacterium Nostoc punctiforme ATCC 29133 was obtained by random transposon insertion into open reading frame NpR1273. The absence of scytonemin under conditions of induction by UV irradiation was the single phenotypic difference detected in a comparative analysis of the wild type and the mutant. A cause-effect relationship between the phenotype and the mutation in NpR1273 was demonstrated by constructing a …