A5054516165- Microbial Community Ecology and Physiology
- Soil Carbon and Nitrogen Dynamics
- Genomics and Phylogenetic Studies
- Antimicrobial Peptides and Activities
- Methane Hydrates and Related Phenomena
- Antimicrobial agents and applications
- Atmospheric and Environmental Gas Dynamics
- Legume Nitrogen Fixing Symbiosis
- Mine drainage and remediation techniques
- Bacterial biofilms and quorum sensing
- Polydiacetylene-based materials and applications
- Mycorrhizal Fungi and Plant Interactions
- Anaerobic Digestion and Biogas Production
- Bacteriophages and microbial interactions
- Gut microbiota and health
- Hydrocarbon exploration and reservoir analysis
- Forest Ecology and Biodiversity Studies
- Plant nutrient uptake and metabolism
- Metal Extraction and Bioleaching
- Chemical Analysis and Environmental Impact
- Indigenous Studies and Ecology
- Biosensors and Analytical Detection
- Ecology and Vegetation Dynamics Studies
- Water Treatment and Disinfection
- Coastal wetland ecosystem dynamics
University of Massachusetts Amherst
2015-2025
University of Massachusetts Boston
2024
University of Massachusetts System
2012
Norwegian Water
2009
Marymount University
2009
University of California, Davis
2006
Michigan State University
1999
Ecologie Microbienne Lyon
1998-1999
Current methods to improve the engineering properties of sands are diverse with respect methodology, treatment uniformity, cost, environmental impact, site accessibility requirements, etc. All these have benefits and drawbacks, there continues be a need explore new possibilities soil improvement, particularly as suitable land for development becomes more scarce. This paper presents results study in which natural microbial biological processes were used engineer cemented matrix within...
The Amazon rainforest is the Earth’s largest reservoir of plant and animal diversity, it has been subjected to especially high rates land use change, primarily cattle pasture. This conversion had a strongly negative effect on biological reducing number species homogenizing communities. We report here that microbial biodiversity also responds rainforest, but in manner different from plants animals. Local taxonomic phylogenetic diversity soil bacteria increases after conversion, communities...
Amphiphilic cationic polynorbornene derivatives, soluble in water, were prepared from modular norbornene monomers, with a wide range of molecular weights (Mn = 1600−137 500 g/mol) and narrow polydispersities (PDI 1.1−1.3). The antibacterial activity determined by growth inhibition assays the hemolytic against human red blood cells measured compared to determine selectivity polymers for bacterial over mammalian cells. effects monomer repeat unit hydrophobicity polymer weight on activities...
Synthetic Mimics of Antimicrobial Peptides (SMAMPs) imitate natural host-defense peptides, a vital component the body’s immune system. This work presents molecular construction kit that allows easy and versatile synthesis broad variety facially amphiphilic oxanorbornene-derived monomers. Their ring-opening metathesis polymerization (ROMP) deprotection provide several series SMAMPs. Using amphiphilicity, monomer feed ratio, weight as parameters, polymers with 533 times higher selectivitiy...
High-throughput RNA sequencing offers broad opportunities to explore the Earth virome. Mining 5,150 diverse metatranscriptomes uncovered >2.5 million virus contigs. Analysis of >330,000 RNA-dependent polymerases (RdRPs) shows that this expansion corresponds a 5-fold increase known diversity. Gene content analysis revealed multiple protein domains previously not found in viruses and implicated virus-host interactions. Extended RdRP phylogeny supports monophyly five established phyla reveals...
Metagenomes encode an enormous diversity of proteins, reflecting a multiplicity functions and activities
Historically neglected by microbial ecologists, soil viruses are now thought to be critical global biogeochemical cycles. However, our understanding of their distribution, activities and interactions with the microbiome remains limited. Here we present Global Soil Virus Atlas, a comprehensive dataset compiled from 2,953 previously sequenced metagenomes composed 616,935 uncultivated viral genomes 38,508 unique operational taxonomic units. Rarefaction curves Atlas indicate that most diversity...
ABSTRACT The change in vegetative cover of a Hawaiian soil from forest to pasture led significant changes the composition bacterial community. DNAs were extracted both habitats and compared for abundance guanine-plus-cytosine (G+C) content, by analysis phylotypes small-subunit ribosomal DNA (SSU rDNA) amplified fractions with 63 35% G+C contents, phylogenetic dominant rDNA clones 63% content fraction. All three methods showed differences between habitats, providing evidence that vegetation...
Polyguanidinium oxanorbornene (PGON) was synthesized from norbornene monomers via ring-opening metathesis polymerization. This polymer observed to be strongly antibacterial against Gram-negative and Gram-positive bacteria as well nonhemolytic human red blood cells. Time-kill studies indicated that this is lethal not just bacteriostatic. In sharp contrast previously reported SMAMPs (synthetic mimics of antimicrobial peptides), PGON did disrupt membranes in vesicle-dye leakage assays...
Land use change in the Amazon rainforest alters taxonomic structure of soil microbial communities, but whether it their functional gene composition is unknown. We used highly parallel microarray technology GeoChip 4.0, which contains 83,992 probes specific for genes linked nutrient cycling and other processes, to evaluate how diversity, abundance similarity targeted responded forest-to-pasture conversion. also evaluated these parameters were reestablished with secondary forest growth. A...
Abstract In this study, amphiphilic polyoxanorbornene with different quaternary alkyl pyridinium side chains were synthesized. The biological efficiencies of these polymers, various substituents, determined by bacterial growth inhibition assays and hemolytic activity (HC 50 ) against human red blood cells (RBCs) to provide selectivity polymers for over mammalian cells. A series substituents (ethyl, butyl, hexyl, octyl, decyl phenylethyl) two molecular weights (3 10 kDa) prepared. impact...
We have investigated how doubly selective synthetic mimics of antimicrobial peptides (SMAMPs), which can differentiate not only between bacteria and mammalian cells, but also Gram-negative Gram-positive bacteria, make the latter distinction. By dye-leakage experiments on model vesicles complementary we were able to relate Gram selectivity structural differences these types. showed that double membrane E. coli rather than difference in lipid composition S. aureus was responsible for...
The current study is aimed at investigating the effect of fine-tuning cationic character synthetic mimics antimicrobial peptides (SMAMPs) on hemolytic and antibacterial activities. A series novel norbornene monomers that carry one, two, or three Boc-protected amine functionalities was prepared. Ring-opening metathesis polymerization (ROMP) monomers, followed by deprotection groups resulted in polynorbornenes charges per monomer repeat unit. Increasing number most hydrophobic polymer reduced...
ABSTRACT The Amazon rainforest, the largest equatorial forest in world, is being cleared for pasture and agricultural use at alarming rates. Tropical deforestation known to cause alterations microbial communities taxonomic phylogenetic levels, but it unclear whether functional groups are altered. We asked free-living nitrogen-fixing microorganisms (diazotrophs) respond using analysis of marker gene nifH . Clone libraries were generated from soil samples collected a primary forest, 5-year-old...
Members of the phylum Acidobacteria are among most abundant soil bacteria on Earth, but little is known about their response to environmental changes. We asked how relative abundance and biogeographic patterning this its subgroups responded forest-to-pasture conversion in soils western Brazilian Amazon. Pyrosequencing 16S rRNA genes was employed assess composition community across 54 samples taken using a spatially nested sampling scheme at landscape level. Numerically, represented 20% total...
Ecological processes regulating soil carbon (C) and nitrogen (N) cycles are still poorly understood, especially in the world's largest agricultural frontier Southern Amazonia. We analyzed parameters samples from pristine rainforest after land use change to pasture crop fields, correlated them with abundance of functional phylogenetic marker genes (amoA, nirK, nirS, norB, nosZ, nifH, mcrA, pmoA, 16S/18S rRNA). Additionally, we integrated these using path analysis multiple regressions....
Silicon wafers and glass surfaces were functionalized with facially amphiphilic antimicrobial copolymers using the "grafting from" technique. Surface-initiated atom transfer radical polymerization (ATRP) was used to grow poly(butylmethacrylate)-co-poly(Boc-aminoethyl methacrylate) from surfaces. Upon Boc-deprotection, these became highly killed S. aureus E. coli 100% in less than 5 min. The molecular weight grafting density of polymer controlled by varying time initiator surface density....
The synthesis and characterization of a series poly(oxanorbornene)-based synthetic mimics antimicrobial peptides (SMAMPs) is presented. In the first part, effect different organic counterions on properties SMAMPs was investigated. Unexpectedly, adding hydrophobicity by complete anion exchange did not increase SMAMPs' activity. It found dye-leakage studies that this due to loss membrane activity these polymers caused formation tight ion pairs between polymer backbone. second molecular charge...
A direct comparison of two strategies for designing antimicrobial polymers is presented. Previously, we published several reports on the use facially amphiphilic (FA) monomers which led to polynorbornenes with excellent activities and selectivities. Our obtained by copolymerization structurally similar segregated monomers, in cationic non-polar moieties reside separate repeat units, less pronounced activities. wide range polymer amphiphilicities was surveyed pairing a oxanorbornene eleven...
ABSTRACT The diversity of microorganisms active within sedimentary rocks provides important controls on the geochemistry many subsurface environments. In particular, biodegradation organic matter in contributes to biogeochemical cycling carbon and other elements strongly impacts recovery quality fossil fuel resources. this study, archaeal was investigated along a salinity gradient spanning 8 3,490 mM Cl − shale rich CH 4 derived from hydrocarbons. Shale pore waters collected wells main...
Here we report the modification of an amphiphilic antibacterial polynorbornene, Poly3, via incorporation hydrophilic, biocompatible groups. The sugar, zwitterionic, and polyethylene glycol based moieties were incorporated in varying ratios by copolymerization postpolymerization techniques. Well-defined copolymers with molecular weights 3 kDa narrow polydispersity indices ranging from 1.08 to 1.15 obtained. effects these modifications on biological activity polymers analyzed determining their...
The diversity of microorganisms active within sedimentary rocks provides important controls on the geochemistry many subsurface environments. In particular, biodegradation organic matter in contributes to biogeochemical cycling carbon and other elements strongly impacts recovery quality fossil fuel resources. this study, archaeal was investigated along a salinity gradient spanning 8 3,490 mM Cl(-) shale rich CH(4) derived from hydrocarbons. Shale pore waters collected wells main...