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Maurice Moloney

Publications and source records attributed to Maurice Moloney.

4 recordsLinked to original sources
PubMed2006

Biotechnological approaches for the production of polyhydroxyalkanoates in microorganisms and plants - a review.

The increasing effect of non-degradable plastic wastes is a growing concern. Polyhydroxyalkanoates (PHAs), macromolecule-polyesters naturally produced by many species of microorganisms, are being considered as a replacement for conventional plastics. Unlike petroleum-derived plastics that take several decades to degrade, PHAs can be completely bio-degraded within a year by a variety of microorganisms. This biodegradation results in carbon dioxide and water, which return to the environment. Attempts based on various methods have been undertaken for mass production of PHAs. Promising strategies involve genetic engineering of microorganisms and plants to introduce production pathways. This challenge requires the expression of several genes along with optimization of PHA synthesis in the host. Although excellent progress has been made in recombinant hosts, the barriers to obtaining high quantities of PHA at low cost still remain to be solved. The commercially viable production of PHA in crops, however, appears to be a realistic goal for the future.

Alkanes↗
PubMed2006

Mitigation of establishment of Brassica napus transgenes in volunteers using a tandem construct containing a selectively unfit gene.

Transgenic oilseed rape (Brassica napus) plants may remain as 'volunteer' weeds in following crops, complicating cultivation and contaminating crop yield. Volunteers can become feral as well as act as a genetic bridge for the transfer of transgenes to weedy relatives. Transgenic mitigation using genes that are positive or neutral to the crop, but deleterious to weeds, should prevent volunteer establishment, as previously intimated using a tobacco (Nicotiana tabacum) model. A transgenically mitigated (TM), dwarf, herbicide-resistant construct using a gibberellic acid-insensitive (Deltagai) gene in the B. napus crop was effective in offsetting the risks of transgene establishment in volunteer populations of B. napus. This may be useful in the absence of herbicide, e.g. when wheat is rotated with oilseed rape. The TM dwarf B. napus plants grown alone had a much higher yield than the non-transgenics, but were exceedingly unfit in competition with non-transgenic tall cohorts. The reproductive fitness of TM B. napus was 0% at 2.5-cm and 4% at 5-cm spacing between glasshouse-grown plants relative to non-transgenic B. napus. Under screen-house conditions, the reproductive fitness of TM B. napus relative to non-transgenic B. napus was less than 12%, and the harvest index of the TM plants was less than 40% of that of the non-transgenic competitors. The data clearly indicate that the Deltagai gene greatly enhances the yield in a weed-free transgenic crop, but the dwarf plants can be eliminated when competing with non-transgenic cohorts (and presumably other species) when the selective herbicide is not used.

Brassica napus↗
PubMed2003

Precise and efficient cleavage of recombinant fusion proteins using mammalian aspartic proteases.

Expression of recombinant proteins as translational fusions is commonly employed to enhance stability, increase solubility and facilitate purification of the desired protein. In general, such fusion proteins must be cleaved to release the mature protein in its native form. The usefulness of the procedure depends on the efficiency and precision of cleavage and its cost per unit activity. We report here the development of a general procedure for precise and highly efficient cleavage of recombinant fusion proteins using the protease chymosin. DNA encoding a modified pro-peptide from bovine chymosin was fused upstream of hirudin, carp growth hormone, thioredoxin and cystatin coding sequences and expressed in a bacterial Escherichia coli host. Each of the resulting fusion proteins was efficiently cleaved at the junction between the pro-peptide and the desired protein by the addition of chymosin, as determined by activity, N-terminal sequencing and mass spectrometry of the recovered protein. The system was tested further by cleavage of two fusion proteins, cystatin and thioredoxin, sequestered on oilbody particles obtained from transgenic Arabidopsis seeds. Even when the fusion protein was sequestered and immobilized on oilbodies, precise and efficient cleavage was obtained. The precision, efficiency and low cost of this procedure suggest that it could be used in larger scale manufacturing of recombinant proteins which benefit from expression as fusions in their host organism.

Amino Acid Sequence↗