Publications by authors named "Philip A Lessard"

Carbohydrases are often incorporated into livestock feed as digestive aids to improve animal performance. AC1 is a thermostable carbohydrase with β-1,4-glucanase, endo-cellulase, and cellobiohydrolase activity. AC1 has been expressed in corn, where it accumulates in the grain for easy inclusion in animal diets.

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The objective of this study was to determine the available P () release curve for a new phytase source, GraINzyme Phytase (Agrivida Inc., Woburn, MA), which is expressed in corn containing an engineered phytase called Phy02. Plant-expressed phytases are created by inserting phytase-encoding genes into plants resulting in their ability to produce seeds with increased concentrations of phytase.

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Antimicrobial resistance is a significant challenge for human and animal health, and developing effective antibiotic-free treatments is a strategy to help mitigate microbial resistance. The global poultry industry faces growing challenges from Eimeria-induced coccidiosis, a serious enteric disease of chickens that currently requires treatment using ionophore antibiotics. Eimeria stimulates interleukin-10 (IL-10) expression in the small intestine and caecum of infected chickens, suppressing their immune response and facilitating disease progression.

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A 41-d feeding trial was conducted to determine the efficacy of a corn-expressed phytase (GZ; GraINzyme, Agrivida Inc., Woburn, MA) on the live performance, bone characteristics, and P digestibility of nursery pigs fed a reduced P diet. Weaned piglets (21 ± 3 d; n = 324) were acclimated on a common diet for 7 d (phase 1) before randomization into 54 single-sex pens (5 gilt and 4 barrow pens per treatment) containing 6 pigs (6.

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We used a microarray targeting 3,524 genes to assess the transcriptional response of the actinomycete Rhodococcus aetherivorans I24 in minimal medium supplemented with various substrates (e.g., PCBs) and in both PCB-contaminated and non-contaminated sediment slurries.

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Here we report the complete genome sequence of Teredinibacter turnerae T7901. T. turnerae is a marine gamma proteobacterium that occurs as an intracellular endosymbiont in the gills of wood-boring marine bivalves of the family Teredinidae (shipworms).

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Bacteria belonging to the Gram-positive actinomycete species, Rhodococcus erythropolis, are diverse not only in terms of metabolic potentials but the plasmids they encode. It was shown previously that the R. erythropolis AN12 genome harbors a 6.

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Pulsed-field gel electrophoresis (PFGE) revealed three previously uncharacterized megaplasmids in the genome of Rhodococcus erythropolis AN12. These megaplasmids, pREA400, pREA250, and pREA100, are approximately 400, 250, and 100kb, respectively, based on their migration in pulsed-field gels. Genetic screening of an AN12 transposon insertion library showed that two megaplasmids, pREA400, and pREA250, are conjugative.

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Background: Gram-positive bacteria of the genus Rhodococcus have shown an extraordinary capacity for metabolizing recalcitrant organic compounds. One hindrance to the full exploitation of Rhodococcus is the dearth of genetic tools available for strain manipulation. To address this issue, we sought to develop a plasmid-based system for genetic manipulation of a variety of Rhodococcus strains.

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Rhodococcus sp. I24 can oxygenate indene via at least three independent enzyme activities: (i) a naphthalene inducible monooxygenase (ii) a naphthalene inducible dioxygenase, and (iii) a toluene inducible dioxygenase (TID). Pulsed field gel analysis revealed that the I24 strain harbors two megaplasmids of approximately 340 and approximately 50 kb.

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We report the successful culture of oil palm (Elaeis guineensis Jacq.) suspension cells in a bioreactor. In vitro propagation of this perennial monocotyledonous tree is an important part of the oil palm industry's approach to clonal propagation of high-yielding accessions.

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Eurycoma longifolia Jack. is a treelet that grows in the forests of Southeast Asia and is widely used throughout the region because of its reported medicinal properties. Widespread harvesting of wild-grown trees has led to rapid thinning of natural populations, causing a potential decrease in genetic diversity among E.

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We demonstrate a general approach for metabolic engineering of biocatalytic systems comprising the uses of a chemostat for strain improvement and radioisotopic tracers for the quantification of pathway fluxes. Flux determination allows the identification of target pathways for modification as validated by subsequent overexpression of the corresponding gene. We demonstrate this method in the indene bioconversion network of Rhodococcus modified for the overproduction of 1,2-indandiol, a key precursor for the AIDS drug Crixivan.

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Introducing and expressing foreign genes in plants present many technical challenges that are not encountered with microbial systems. This review addresses the variety of issues that must be considered and the variety of options that are available, in terms of choosing transformation systems and designing recombinant transgenes to ensure appropriate expression in plant cells. Tissue specificity and proper developmental regulation, as well as proper subcellular localization of products, must be dealt with for successful metabolic engineering in plants.

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