The use of disposable gaas generating kits for the growth of hydrogen-oxidizing bacteria and the determination of hydrogen autotrophy

A simplified procedure for the determination of autotropic growth of hydrogen-oxidizing bacteria has been developed. The method uses commercially available disposable hydrogen and carbon dioxide kits, commonly used in anaerobic bacteriology, to produce a gaseous atmosphre containing by volume approximately 41% hydrogen, 6% carbon dioxide, 11% oxygen and 42% nitrogen. The atmosphere was suitable for the growth of strains assigned to the species Alcaligenes eutrophus, Alcaligenes paradoxus, Paracoccus denitrificans, Pseudomonas facilis, Pseudomonas flava, Pseudomonas palleronii, Pseudomonas saccahrophilia and Rhodococcus sp. ('Nocardia opaca'). The method can also be used for the screening of hydrogen-oxidizing ability in bacterial isolates, thus eliminating the need for complex gas mixing devices or expensive gas mixtures

Taxonomic note: V. B. D. Skerman (1921-1993), a reforming force in bacterial systematics and nomenclature

Professor V. B. D. Skerman made major contributions to the reform of bacterial systematics which are now in place and appreciated. He was the catalyst and a driving force for a series of reforms which led to the clarification of bacterial nomenclature. He reorganized the International Committee on Systematic Bacteriology and the Judicial Commission by persuading the members to accept and develop the statutes that govern their operations and also persuaded them to adopt a new starting date for bacterial nomenclature. The resulting revision of the International Code of Nomenclature of Bacteria and the publication of the Approved Lists of Bacterial Names under his direction leave a legacy of procedures for the orderly progress of bacterial taxonomy and nomenclature

Isolation of manganese-oxidizing Pedomicrobium cultures from water by micromanipulation

A method for the isolation of manganese-oxidizing pedomicrobia from water is described. The method employs a combination of growth on a manganese containing indicator medium and micromanipulation. Pedomicrobia are slow-growing and are frequently overgrown by spreading bacteria. Colonies of manganese-oxidizing strains are easily detected at an early stage of development because of the accumulation of black manganese oxide. Micromanipulation allows selection of cells from microcolonies before they are overgrown. The procedure has been successfully used to isolate manganese-oxidizing Pedomicrobium cultures from water distribution systems experiencing persistent manganese-related dirty water problems. Considerable savings in time and materials have been made compared with conventional dilution plating techniques

Glucose-6-phosphate dehydrogenase in cell free extracts of Zymomonas mobilis

Glucose-6-phosphate dehydrogenase activity in cell free extracts o Zymomonas mobilis showed marked differences when compared with the corresponding enzyme of Escherichia coli. It exhibited 3 times higher activity and the reaction rate over 10 min gave linearity only up to a cell free protein concentration of 0.15 mg protein. This different behaviour was not a function of environmental growth conditions of the culture nor of the nine different assay methods employed. A constant relationship existed between the specific G-6-P dehydrogenase protein and the total protein concentration in the cell free extract. The enzyme was stable for at least 5 h at 4°C in Tris-NaCl-MgCl2-buffer. An investigation of the properties of G-6-P dehydrogenase from Z. mobilis revealed a pH optimum of 8.7 with a rapid decline towards the acidic and a small decrease towards the alkaline side. The Km values were 5×10-4m for glucose-6-phosphate and 3.6×10-5m NADP+. The addition of 1×10-2m MgCl2 produced optimal activity but higher concentrations inhibited the enzyme reaction. These results were discussed with those from other sources and found to be unique for Zymomonas mobilis

Acute epiglottitis in childhood: Report of an increased incidence in Victoria

The incidence of acute epiglottitis treated in Melbourne, Australia at the Royal Children's Hospital (RCH) has increased from an average of 14 cases per year during 1975-79 to 49 cases per year during 1980-81. Less marked increases have occurred for H. influenzae meningitis and bacteremia and H. influenzae (untyped) isolation from respiratory tract cultures. A review of 171 cases of acute epiglottitis showed no significant differences between the 1975-79 and 1980-81 patients with respect to sex, age, seasonal incidence, prodromal length, prodromal symptoms geographical location, polymorphonuclear cell count, or disease severity. Patients treated in 1980-81 had fewer complications (12% versus 22%,

The importance of high aesthetic quality potable water in tourist and recreational areas

Tourists have high expectations of the living standards in tourist and recreational areas and are usually less tolerant of substandard services than are local residents. One of the most obvious services experienced by tourists is the drinking water quality. Whereas the microbiological quality of drinking water is usually well controlled with respect to public health risk, many communities experience problems with the aesthetic quality of their water supplies. Such problems include colour and turbidity, taste and odour, and overchlorination. In areas where rat water sources contain manganese and iron it is essential that such nuisance metals are treated out to low levels. Failure to do so results in the accumulation of metal oxides in biofilm or chemical coatings on the surfaces of water mains. When this material sloughs off, consumers receive 'dirty water' which causes irreversible staining of laundry and recreational facilities such as swimming pools. Communities which rely on tourism as their major industry must pay serious attention to the treatment of their potable water or face the economic consequences of having a poor reputation. Current research on the relationship between manganese concentration and consumer acceptability has indicated that WHO and NHMRC recommended levels for manganese in drinking water are not sufficiently low to meet the high aesthetic quality requirements of water in tourist and recreational areas.Whereas the microbiological quality of drinking water is usually well controlled with respect to public health risk, many communities experience problems with the aesthetic quality of their water supplies. Such problems include colour and turbidity, taste and odour, and overchlorination. In areas where raw water sources contain manganese and iron it is essential that these nuisance metals are treated out to low levels. Failure to do so results in the accumulation of metal oxides in biofilm or chemical coatings on the surfaces of water mains. When this material sloughs off, consumers receive 'dirty water' which causes irreversible staining of laundry and recreational facilities such as swimming pools. Current research on the relationship between manganese concentration and consumer acceptability has indicated that WHO and NHMRC recommended levels for manganese in drinking water are not sufficiently low to meet the high aesthetic quality requirements of water in tourist and recreational areas

Cellulolytic and dextranolytic Gram‐negative bacteria: revival of the genus Cellvibrio

Blackall, Linda L., Hayward, A.C. & Sly, L.I. 1985. Cellulolytic and dextranolytic Gram‐negative bacteria: revival of the genus Cellvibrio. Journal of Applied Bacteriology59, 81–97. Nine bacterial strains were isolated from rhizosphere soils by enrichment in a defined mineral salts medium containing either cellulose or dextran as the sole carbon source. These and 17 reference strains, including representatives of two species of the invalid genus Cellvibrio, were characterized on morphological, biochemical and physiological properties. Numerical analyses were performed on the results using two different measures of similarity and methods of clustering. Eight of the nine isolates, three unnamed reference strains and the strains of Cellvibrio showed a high level of similarity and comprised a single cluster in both methods of analysis. The salient properties of strains in this cluster were: Gram‐negative, aerobic, slender rods, some having a slightly curved axis; mixed flagellation; oxida‐tive metabolism of glucose; extensive hydrolytic ability on complex polysaccharides; production of curdlan polysaccharide on glucose. Revival of the genus Cellvibrio (Winogradsky 1929) gen. nov., with an amended description and a new type species Cellvibrio mixtus sp. nov. is proposed. Copyrigh