Starch-based bioethanol process innovation

Starch liquefaction and saccharification are key processing steps in the bioethanol industry. The rate-limiting α-amylase plays an important role due to its endo-glycosidic activity. Work carried out in this thesis on barley α-amylase focused on ER retention to boost recombinant protein expression in planta and purification of the protein to facilitate a cascade refinery approach allowing other high value proteins to be co-produced together with starch for bioethanol production. Results obtained generated evidence for context-dependence of the ER retention motif HDEL, the existence of an HDEL-independent ER retention mechanism and quantitative data showing toxicity or detrimental effects of HDEL overdose. Results also revealed an effect of peptide tags on N-linked glycosylation as well as evidence that expression levels and systems can strongly affect glycosylation of proteins in the secretory pathway. Furthermore, α-amylase endo-glycosidic action on long glucan chains was shown not to be rate limiting in starch saccharification but the presence of short oligomers and their susceptibility to hydrolysis by fungal amyloglucosidase must be considered next. Interestingly, starch saccharification using acid hydrolysis was more efficient compared to enzyme catalysed hydrolysis. In order to optimise the saccharification process further, the research centred on exploring enzymes with raw-starch digesting properties at low temperature and increased specificity for low molecular weight oligosaccharides. Therefore, an alpha amylase-like gene was identified in ripening plantain (Musa acuminata × balbisiana) using degenerate primers. The gene encodes a putative protein product with close homology to chloroplast α-amylases from Ricinus communis, and Arabidopsis thaliana (AtAMY3)

Potential materials for food packaging from nanoclay/natural fibres filled hybrid composites

The increasing demand for new food packaging materials which satisfy people requirements provided thrust for advancement of nano-materials science. Inherent permeability of polymeric materials to gases and vapours; and poor barrier and mechanical properties of biopolymers have boosted interest in developing new strategies to improve these properties. Research and development in polymeric materials coupled with appropriate filler, matrix-filler interaction and new formulation strategies to develop composites have potential applications in food packaging. Advancement in food packaging materials expected to grow with the advent of cheap, renewable and sustainable materials with enhanced barrier and mechanical properties. Nanoparticles have proportionally larger surface area and significant aspect ratio than their micro-scale counterparts, which promotes the development of mechanical and barrier properties. Nanocomposites are attracting considerable interest in food packaging because of these fascinating features. On the other hand, natural fibres are susceptible to microorganisms and their biodegradability is one of the most promising aspects of their incorporation in polymeric materials. Present review article explain about different categories of nanoclay and natural fibre based composite with particular regard to its applications as packaging materials and also gives an overview of the most recent advances and emerging new aspects of nanotechnology for development of hybrid composites for environmentally compatible food packaging materials

Biofuels in the quest for sustainable energy development.

The numerous energy challenges facing the world coupled with the lack of sustainability of the non-renewable 'fossil fuels world' has led the search to sustainable alternatives. Biofuel has emerged as an alternative with great promise with quite some problems to contend with; this include the development of feasible technologies such as the search for highly efficient saccharification enzymes; and the high cost of production which make the fuel price exorbitant. Thus there is need for cheap processing technologies in order to make the biofuels affordable. We reviewed lots of progress made on biofuel development and some cutting-edge technologies being developed for their production

Remediation of soil contaminated with toxic organic compounds using microorganisms

Microorganisms, especially genetically modified microorganisms have continued to attract attention as a safer and environmentally friendly alternative in the bioremediation of contaminated environments such as soil and water bodies. Soil pollution by organic compounds such as pesticides, industrial and agricultural solvents, dyes, pigments, additives etc. is on the increase worldwide as a result of industrialization and agricultural modernization. Toxicity from these and other related pollutants have constituted a major challenge to humans as well as the environment. Therefore, it is important to apply effective remediation measures to reduce the levels of these toxicants so as to minimize the risk of bioaccumulation in agricultural food products. Bioremediation using biological materials viz; whole cells, cell extracts, isolated enzymes etc. is one of the most effective and environmentally friendly approaches currently in use. This paper therefore, reviews the current microbial remediation strategies of soil contaminated with various organic pollutants.Keywords: Bioremediation, Microorganisms, Pollutants, Soil, Organi