Proving the identity of a complementing gene in Aspergillus nidulans by tandem integration and loop-out repair

This reports a convenient way for tagging a complementing sequence (gene or gene fragment) for use in tandem integration/loopout repair. It was used to verify cloning of the hypA locus. The backbone of a hypA1-complementing plasmid was tagged with pLH1, a Tn5 transposon having a diagnostic BamH1 fragment containing argB+. This was transformed into a hypA1, argB2 strain of A. nidulans. Transformants with an integrated copy of the tagged plasmid were allowed to self-mate. Given integration at hypA, and that the plasmid sequence was from the hypA locus, this led to loopout repair of the hypA1 defect with concomitant loss of argB+

A study of human mood tagging of musical pieces

We conducted a survey in which participants were required to label the mood conveyed within a variety of musical pieces. Two different representations of mood were used, the 2D emotion space as well as updated Hevner mood labels. The results show that survey responses using the two mood representations were both consistent as well as sensible. In terms of music piece characteristics that influenced participant's responses, it has been shown that the intensity/energy, tempo and beat strength consistently influenced participant's mood responses while tonality and pitch did not. Finally, the survey has raised many important questions relating to labeling musical pieces with mood, including the handling of a musical piece conveying more than one mood simultaneously, as well as a musical piece that conveys rapid mood changes

Fundamentals of growth, storage, genetics and microscopy of Aspergillus nidulans

This is a compendium of protocols for using Aspergillus nidulans in genetic, molecular, and cell biological investigations, originally written for members of my research group. It also summarizes our common growth media and nutritional supplements, many of which originally appeared elsewhere but now are difficult to locate. All solutions, tools, etc. are assumed to be sterile. All water should be sterile distilled or equivalent. Temperatures are in °C. Strains are available from the Fungal Genetics Stock Center (http://www.fgsc.net/)

A medium for rapid cleaning of Aspergillus cleistothecia

Aspergillus cleistothecia are usually cleaned of adherent Hülle cells by rolling them on an agar surface, which is a tedious process. We have found that incorporating 0.5 - 1.0 % diatomaceious earth (also caled Celite) into 4% agar, as a mild abrasive, helps to speed cleaning about 5-fold (average 10 min reduced to 2 min)

Symbiotic fungal endophytes that confer tolerance for plant growth in saline and dry soils

Non-Peer Reviewe

Phytoremediation of Alberta oil sand tailings using native plants and a fungal endophyte species

Non-Peer ReviewedThe Athabasca Oil Sands produce a high volume byproduct called tailing sands (TS). Typically, TS are remediated by planting young trees in large quantities of mulch (from elsewhere) plus mineral fertilizer. This is costly and labour intensive. Fungal endophytes colonize host plants without causing disease. Some endophytes confer plant tolerance to harsh environments. Trichoderma harzianum strain TSTh20-1 was isolated from a plant growing on Athabasca oil tailings sand (TS). TS are a high volume waste product from oil sand extraction that the industry is required to remediate. TS are low in organic carbon and mineral nutrients, and are hydrophobic due to residual hydrocarbons. In greenhouse trials, TSTh20-1 supports growth of tomato seedlings on TS without fertilizer. TSTh20-1 is a promising candidate for economical TS remediation. We tested 23 plant species for seed germination and growth on TS in the presence of TSTh20-1. The four best candidates are currently being used in microcosm-scale growth trials, and for outdoor mesocosm trials this summer. Potential mechanisms that contribute to endophyte-induced plant growth promotion are also being assessed. TSTh20-1 is nutritionally frugal, which may be characteristic of other plant fungal endophytes. We are also tagging TSTh20-1 with GFP to follow it in the plant and in the environment

Endophytic hyphal compartmentalization is required for successful mycobiont-wheat interaction as revealed by confocal laser microscopy

Non-Peer ReviewedRoot endophytic fungi are seen as promising alternatives to replace chemical fertilizers and pesticides in sustainable and organic agriculture systems. Fungal endophytes structure formations play key roles in symbiotic intracellular association with plant-roots. To compare the morphologies of Ascomycete endophytic fungi in wheat, we analyzed growth morphologies during endophytic development of hyphae within the cortex of living vs dead root cells. Confocal laser scanning microscopy (CLSM) was used to characterize fungal cell morphology within lactofuchsin-stained roots. Cell form regularity Ireg and cell growth direction Idir, indexes were used to quantify changes in fungal morphology. Endophyte fungi in living roots had a variable Ireg and Idir values, low colonization abundance and patchy colonization patterns, whereas the same endophyte species in dead (γ-irradiated) roots had consistent form of cells and mostly grew parallel to the root axis. Knot, coil and vesicle structures dominated in living roots, as putative symbiotic functional organs. Finally, an increased hypha septation in living roots might indicate local specialization within endophytic Ascomycota. Our results suggested that the applied method could be expanded to other septate fungal symbionts

Endophytic Fungus, TSTh20-1, promotes plant growth on oil sands tailings

Non-Peer Reviewe

GreenSTEM’s microbe technology is an efficient, effective, and affordable way to clean up fuel and chemical spills

Non-Peer ReviewedPetroleum hydrocarbons are used as fuel and for chemical synthesis. If spilled, fuels and chemicals poison our soil and water, causing local environmental disasters. Bioremediation uses organisms to clean up (remediate) pollutants. We have isolated and characterized microbe strains from contaminated sites, and use them to remediate contaminated sites elsewhere. We identify our strains using their DNA sequences and their appearance. Some microbes, called fungal endophytes, form symbioses, in other words metabolic partnerships between a plant and a fungus. These symbioses have been shown to stimulate plant growth and root formation, even on contaminated soil. Surprisingly, some of our other microbes can degrade hydrocarbons underground, without plants. GreenSTEM has powerful technology: we use native microbes to degrade hydrocarbons and chemicals as they grow on the contaminants as food. Based on our progress to date with fuels and other chemicals, we anticipate isolating new strains specific for other intractable toxins

Diver navigation system acoustic signal encoding/decoding optimisation

This thesis describes the optimisation of the encoding and decoding processes used to transmit and receive frequency coded data tones acoustically during the operation of an underwater diver navigation system. The aim was to reduce the time required to both generate these data tones for transmission as well as to decode these tones during reception. Encoding of the data tones is performed using a phase lock loop under the control of a microcontroller. A technique was developed which combined both hardware and software modifications to effectively halve the phase lock loop settling time, and therefore the time required to generate these tones. Decoding of these data tones is achieved using the Fast Fourier Transform. Alternative forms of the Discrete Fourier Transform were explored to find the most efficient in terms of execution time. Numerous software optimisations were then applied which led to a reduction in program execution time of 54 % with no penalty in program complexity or length. Testing of the system under identical real-life operating conditions showed no evidence of any system performance degradation as a result of these optimisations