Pathogenic effects of bacteria isolated from larvae of Hylesia metabus Crammer (Lepidoptera: Saturniidae).

Hylesia metabus larvae are susceptible to several pathogens indigenous to the area in which they are found. Some larvae show symptoms characteristic of bacterial infection; they become flaccid and lethargic, and show a marked loss of appetite. We isolated and identified 29 bacterial strains from live, dead and experimentally infected H.

Growth rate and production of a microcin by Salmonella typhimurium LT2 (strain M799-0) in continuous culture.

The production of a bacteriostatic microcin, of molecular weight 520 kD by Salmonella typhimurium LT2, strain M799-0, was studied in continuous culture. The effect of specific growth rate (mu) on microcin production was measured under aerobic and anaerobic conditions. In aerobiosis the microcin specific production rate (qp) was found to be strictly associated with cell growth.

Comparative study of the ribosomal RNA from Leishmania and Trypanosoma.

The ribosomal RNA from several stocks of the genera Leishmania and Trypanosoma were studied by gel electrophoresis, sedimentation on sucrose density gradients and RNA/DNA hybridization experiments. Three major components were observed after electrophoresis in polyacrylamide gels (PAGE-SDS), the relative molecular masses being respectively: X1 = 0.83 megadaltons, X2 = 0.

Inhibitors of cytoplasmic protein synthesis purified from rat liver mitochondria.

Purified mitochondria from rat liver were found to contain protein synthesis inhibitors, that could be extracted by disruption of mitochondrial membranes and fractionated by gel filtration into two fractions of low and high molecular weight. Small size inhibitors were also released from the latter peak by high ionic strength followed by gel filtration. Both types of factors inhibit incorporation of radioactive amino acids into protein by liver cytoplasmic polysomes programmed with endogenous mRNA or poly U, and by rabbit reticulocyte lysates programmed with added globin mRNA and by incubations of Walker carcinoma cells.

Creation of a data base for sequences of ribosomal nucleic acids and detection of conserved restriction endonucleases sites through computerized processing.

As part of a project pertaining the organization of ribosomal genes in Kinetoplastidae, we have created a data base for published sequences of ribosomal nucleic acids, with information in Spanish. As a first step in their processing, we have written a computer program which introduces the new feature of determining the length of the fragments produced after single or multiple digestion with any of the known restriction enzymes. With this information we have detected conserved SAU 3A sites: (i) at the 5' end of the 5.