Free and microencapsulated Erwinia herbicola for the production of tyrosine

Identification of the antibacterial compound produced by the marine epiphytic bacterium Pseudovibrio sp. D323 and related sponge-associated bacteria

Surface-associated marine bacteria often produce secondary metabolites with antagonistic activities. In this study, tropodithietic acid (TDA) was identified to be responsible for the antibacterial activity of the marine epiphytic bacterium Pseudovibrio sp. D323 and related strains. Phenol was also produced by these bacteria but was not directly related to the antibacterial activity. TDA was shown to effectively inhibit a range of marine bacteria from various phylogenetic groups. However TDA-producers themselves were resistant and are likely to possess resistance mechanism preventing autoinhibition. We propose that TDA in isolate D323 and related eukaryote-associated bacteria plays a role in defending the host organism against unwanted microbial colonisation and, possibly, bacterial pathogens.

Bowel as a kidney substitute in renal failure

Maintenance peritoneal dialysis and hemodialysis sustain the lives of approximately 250,000 uremic patients in industrialized nations worldwide. The cost of uremia therapy, however, exceeds health care budgets in developing countries. As a consequence, most of those alive today have no chance of effective treatment should their kidneys fail. Extraction, modification, or recycling of nitrogenous wastes by the gastrointestinal tract is a potentially low-cost means of substituting for missing renal function. Multiple approaches to the bowel as a substitute kidney have been attempted. Direct removal of nitrogen-containing compounds by an external gut fistula, gastric, ileal, or colonic gavage (dialysis) or induced diarrhea extract water and urea but only minimal amounts of larger molecules such as creatinine. Binding of nitrogen compounds to inert orally administered sorbents such as charcoal or oxystarch has been pursued in advanced uremia. Modification of nitrogen compounds by ingesting enzymes derived from soil bacteria or packaged in artificial cells is an approach that, although exciting, is incompletely evaluated. Evidence indicates that strains of bacteria can be induced to synthesize enzymes that recycle urea and other nitrogen compounds retained by uremic individuals. Clinical trials to substantiate uncontrolled trials of bowel substitution in renal failure will, if positive, accelerate development of a practical regimen to extend life where no other means are possible.