New antibiotics are urgently required by human medicine as pathogens emerge with developed resistance to almost all antibiotic classes. Pioneering approaches, methodologies and technologies have facilitated a new era in antimicrobial discovery. Innovative culturing techniques such as iChip and co-culturing methods which use 'helper' strains to produce bioactive molecules have had notable success. Exploiting antibiotic resistance to identify antibacterial producers performed in tandem with diagnostic PCR based identification approaches has identified novel candidates. Employing powerful metagenomic mining and metabolomic tools has identified the antibiotic'ome, highlighting new antibiotics from underexplored environments and silent gene clusters enabling researchers to mine for scaffolds with both a novel mechanism of action and also few clinically established resistance determinants. Modern biotechnological approaches are delivering but will require support from government initiatives together with changes in regulation to pave the way for valuable, efficacious, highly targeted, pathogen specific antimicrobial therapies.

The thermotolerant yeast strain, Khyveromyces marxianus lMB3 was shown to be capable of growth and ethanol production on lactose containing media at 45°C. On media containing 4% (w/v) lactose, ethanol production increased to 6.Og/l within 50h and this represented 29% of theoreti+ yield. During growth on lactose containing media the organism was shown to produce a cell-associated ~galactosidase and no significant enzyme could be detected in the extracellular culhue f%rate. Addition of P-galactosidase, released from Khyveromyces murxianzis IMB3 cells, to active fermentations, resulted in increasing ethanol production to 53% of theoretical yield at 45°C.

In comparing ethanol production by free and Ca-alginate immobilized cultures of the thermotolerant yeast, Kluyverumyces marxianus IMB3, on glucose-containing media at 45°C it was found that initial yields produced by the immobilized culture lagged behind those produced by cultures in free suspension. However, in subsequent batch-feed experiments ir was demonstrated that the ethanol-producing ability of the immobilized preparation increased with successive feeds, while production by the free suspension reduced significantly.

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Oral administration of hen-egg yolk provides protection against specific pathogens. We examined the antibacterial activity of fractionated egg yolk against 2 pathogenic Streptococcus strains, using an in vitro assay. A water-soluble protein fraction (WSPF) of egg yolk consistently inhibited the growth of S. mutans by 25%. The WSPF treated with pancreatin demonstrated > 80% inhibition of bacterial growth. Growth of S. sanguis was completely inhibited. Gel filtration and ion exchange chromatography established that anti-Streptococcal activity resided with lipoproteins. Antibacterial activity was released by crude lipase or a combination of lipase and protease treatment of egg lipoproteins. Thus, hen-egg yolk lipoproteins are important molecules for lipid-mediated antimicrobial activity.