Differential Patterns of Bacteriolytic Activities in Potato in Comparison to Bacteriophage T4 and Hen Egg White Lysozymes

A comparison of the enzymatic activities of endogenous potato bacteriolytic enzymes with bacteriophage T4 and hen egg white lysozyme has been performed. Using Erwinia carotovora atroseptica and Pseudomonas solanacearum as substrates in, comparison to Micrococcus lysodeikticus a differential pattern of bacteriolytic activities could be detected. The expression pattern of endogenous potato lysozymes suggests that their functional activity against phytopathogenic bacteria in planta is unlikely. Antibacterial activities in transformed, T4 lysozyme expressing and non–transformed potato plants are evaluated.     

Volatile fatty acids as indicators of process imbalance in anaerobic digestors

In continuously stirred tank reactor experiments, with manure as substrate at thermophilic temperatures, the use of volatile fatty acids (VFA) as process indicators was investigated. Changes in VFA level were shown to be a good parameter for indicating process instability. The VFA were evaluated according to their relative changes caused by changes in hydraulic loading, organic loading or temperature. Butyrate and isobutyrate together were found to be particularly good indicators. Butyrate and isobutyrate concentrations increased significantly 1 or 2 days after the imposed perturbation, which makes these acids suitable for process monitoring and important for process control of the anaerobic biological system. In addition it was shown in a batch experiment that VFA at concentrations up to 50 mM did not reduce the overall methane production rate. This showed that VFA accumulation in anaerobic reactors was the result of process imbalance, not the cause of inhibition, thus justifying the use of VFA as process indicators.     

malvolio, the Drosophila homologue of mouse NRAMP-1 (Bcg), is expressed in macrophages and in the nervous system and is required for normal taste behaviour.

We report the sequence, expression pattern and mutant phenotype of malvolio (mvl), the Drosophila homologue of mammalian natural resistance-associated macrophage proteins (NRAMPs). In the mouse, this novel transporter is encoded by Bcg, a dominant gene that confers natural resistance to intracellular parasites. mvl was identified in a screen for mutants that affect taste behaviour. We show that loss-of-function as well as insertional mutants in mvl display defects in taste behaviour with no alterations in the physiology of the sensory neurons. Activity of the reporter enzyme beta-galactosidase, that reflects the expression pattern of mvl, is seen in mature sensory neurons and in macrophages. The conceptual translation of the mvl cDNA shows a striking similarity (65% identity) with human NRAMP with almost complete identity in a conserved consensus motif found in a number of ATP-coupled transporters. Based on its phenotype and expression pattern as well as its structural similarities to NRAMPs and a nitrate transporter in Aspergillus nidulans, we discuss a possible role for MVL in nitrite/nitrate transport and its implications.     

Detection of leucochimaerism in bovine twins by DNA fingerprinting

Karyotyping and hypervariable genetic markers indicate extensive leucochimaerism between pairs of dizygotic twins in cattle, a result of placental vascular anastomosis. The extent of this chimaerism includes both kind and number of cells exchanged. All heterosexual twin pairs harboured two types of leucocytes, having either XX or XY chromosome pairs, and 30 of 31 pairs of twins shared identical DNA fingerprints. Although chromosome results from skin fibroblasts indicate that some chimaerism occurs in the skin, the low level allows for differentiation of genotypes between twins. The results warrant against the common practice of using blood samples for DNA typing if twinning is not properly documented.     

ASP-56, a new actin sequestering protein from pig platelets with homology to CAP, an adenylate cyclase-associated protein from yeast.

A new 56 kDa actin-binding protein (ASP-56) was isolated from pig platelet lysate. In falling ball viscosimetry it caused a reduction in viscosity that could be attributed to a decrease in the concentration of polymeric actin. Fluorescence measurements with NBD-labelled actin showed reduction of polymeric actin, too. These results could be explained by sequestering of actin in a non-polymerizable 1:1 ASP-56/actin complex. Sequencing of about 20 tryptic peptides of ASP-56 and comparison with known sequences revealed about 60% homology to the adenylate cyclase-associated protein (CAP) from yeast.