A note on the use of Rappaport-Vassiliadis medium (R10/RV) for the isolation of salmonellas from sewage and sewage sludges

The use of a modified Rappaport broth for the selective enrichment of salmonellas in sewage sludge is described. Comparative trials were carried out using Muller Kauffman--Tetrathionate (MKT) broth and Rappaport-Vassiliadis (R10/RV) medium for selective enrichment. Results have indicated that R10/RV broth is more selective and is to be preferred for routine monitoring.     

Olive Pink and the Encounter with the Academy

Olive Pink studied anthropology at the University of Sydney under Professor A.P. Elkin. Although she did fieldwork among the Northern Aranda and Wailbri of Central Australia, she became disenchanted with anthropology and lived a reclusive life in Alice Springs. In this paper I present a brief outline of her life, particularly during the 1930's I point to the problems she encountered and suggested that she needs to be relocated within her discipline.     

Nitrospira marina gen. nov. sp. nov.: a chemolithotrophic nitrite-oxidizing bacterium

A new chemolithotrophic nitrite-oxidizing bacterium, for which the name Nitrospira marina is proposed, was isolated from the Gulf of Maine. N. marina is a Gramnegative curved rod which may form spirals with 1 to 12 turns. Cells have a unique periplasmic space and lack intracytoplasmic membranes and carboxysomes. N. marina is an obligate chemolithotroph, but best growth is obtained in a mixotrophic medium. N. marina may be one of the most prevalent nitrite-oxidizing bacteria in some oceanic environments. Type strain is field with American Type Culture Collection (ATCC 43039).     

Peroxide oxidation of primary alcohols to aldehydes by chloroperoxidase catalysis

Chloroperoxidase catalyzes the peroxidation of primary alcohols, specifically those that are allylic, propargylic, or benzylic. Aldehydes are the products. The reaction dislays appreciable activity throughout the entire pH range investigated, namely pH 3.0–7.0. This enzyme is the only haloperoxidase of four tested capable of carrying out the reaction. These results further establish chloroperoxidase as a unique haloperoxidase.     

Genetic and physical studies of restriction-deficient mutants of the Inc FIV plasmids R124 and R124/3

Summary R124 and R124/3 are R plasmids that carry the genes for two different restriction and modification systems. The phenotype of strains carrying either of these plasmids along with the F'lac ⁺ plasmid, is restriction-deficient (Res^-). The Res^- phenotype is not due to selection of preexisting mutants but rather to a complex mutational event caused by the F plasmid. Restriction-deficient mutants carry extensive deletions and other DNA rearrangements. Tn7 insertion is used to locate the restriction gene. Many of the Res^- mutants are genetically unstable and revert at exceptionally high frequencies. Reversion is accompanied by DNA rearrangements which result in a net gain of 9 kb of DNA. F derivates of F⁺ which do not cause restriction-deficiency but do cause deletion were used to distinguish between the DNA rearrangements associated with restriction-deficiency and those associated with deletion. From Res⁺ revertants of strains carrying F'lac ⁺ and R124 or R124/3 we have isolated F plasmids that now carry the genes for the R124 or R124/3 restriction and modification systems. It is suggested that interaction between part of the F plasmid and that segment of the R plasmid which controls the switch in Res-Mod specificity which has been observed (Glover et al. 1983) is responsible for the production of restriction-deficiency.     

Construction of recombination-deficient strains of Pseudomonas aeruginosa

Summary The rec-102 mutation had pleiotropic effects in Pseudomonas aeruginosa: low recombination proficiency in conjugation and transduction; high UV sensitivity; inability to induce pyocin R2 by mitomycin C; and increased susceptibility to mitomycin C and nalidixic acid. The rec-102 locus was mapped by R68.45-mediated conjugation in the 45 min region of the PAO chromosome, between argF and thr-9001. By selection for a marker in this region, rec-102 can be introduced into a P. aeruginosa strain of interest using an R68.45 rec-102 donor. The recombination-deficient strains constructed in this way were phenotypically similar to Escherichia coli recA mutants.     

The action of nitrous acid on C-teichoic acid (C-substance) from the walls of Diplococcus pneumoniae

1. C-teichoic acid (C-substance) from the walls of Diplococcus pneumoniae contained free amino groups accessible to attack by nitrous acid. Treatment with nitrous acid, followed by reduction with borohydride and hydrolysis with acid, gave ribitol, glucitol and their respective phosphates. 2. Hydrolysis of the polymer with alkali followed by treatment of products with nitrous acid yielded glucose. 3. When alkali hydrolysis was followed by treatment with a phosphomonoesterase, nitrous acid degradation of C-substance yielded glucose and a disaccharide identified as 2-O-(N-acetylgalactosaminyl)-d-ribitol. 4. A partial structure for C-teichoic acid was deduced in which the order of the constituent residues and the position of phosphodiester linkages were established.     

Fatty Acids in the Lipids of Marine and Terrestrial Nitrifying Bacteria

Fatty acids in the lipids of 19 marine and terrestrial nitrifying bacteria have been analyzed. Ammonia-oxidizing bacteria have a very simple acid composition; palmitic and palmitoleic acid account for 96 to 100% of the total acids. The fatty acids of nitrite-oxidizing bacteria cover a wider range, from C(14) to C(19), but from two to four acids still account for more than 80% of the total acids. Branched iso- and anteiso-acids are present in traces only in 2 of the 19 bacteria. The chemical and morphological similarity between blue-green algae and these bacteria is discussed.