Ginger blotch, a new bacterial disease of the cultivated mushroom, Agaricus bisporus, is described from farms in the UK. The symptoms are distinct from the classical blotch disease caused by Pseudomonas tolaasii. The causative organism has been isolated and identified as a new member of the Pseudomonas fluorescens complex which can be distinguished from Pseudomonas tolaasii by several simple tests.

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Occupational debris from beneath the Roman fort Vindolanda, and lake sediments cored from Seamere in East Anglia were examined for the presence of viable Thermoactinomyces endospores. Up to 104 viable endospores/g dry wt were recovered from the occupational debris at Vindolanda deposited between 1850 to 1890 years ago. Highest numbers were found in layers of bracken and straw litter sandwiched between clay floors within a military building. Associated artefacts and writing tablets have been used to date the various layers. Pollen analyses on core samples from Seamere revealed one region containing a declining percentage of tree pollen and the appearance of cereal and associated weed pollens suggesting the presence of a primitive agricultural community on the shores of the lake. Samples from this section of the core, deposited ca. 1950 to 2750 years ago, contained viable thermoactinomycete endospores. These studies confirm the extreme longevity of Thermoactinomycete endospores and suggest that these organisms may be usefully employed in future archaeological and palaeoecological studies.

Ten types of membrane filter, most with a nominal pore size of 0.45 μm, were compared for their efficiency in recovering Thermoactinomyces endospores from water samples and yielding colonies for viable counts. The endospores were in laboratory‐prepared suspensions from two strains and in river water containing a natural population of actinomycetes and bacteria. There were significant differences in recovery efficiency between membranes used with river water samples; black Sartorius membranes (SM 13006) gave highest colony counts when incubated on selective agar. All membranes except Nuclepore gave good recovery from the spore suspensions but some differences were noted in their ability to recover the two strains. Thus it is inadvisable to use the results of trials on pure cultures prepared in the laboratory to predict the performance of membranes for use with natural water samples. Czapek‐Dox agar with added yeast extract and Casamino acids (CYC) was a superior recovery medium to Trypticase Soy agar (TSA). The efficiency of green Gelman membranes was improved if they were boiled in distilled water before use; in contrast, boiled Oxoid membranes (original type) carried fewer colonies.