After a lapse of nearly 20 years the "cider sickness" organism has been re discovered. On this occasion it was found in apple pulp, this being the first time it has been isolated from a source other than "sick cider". In spite of its presence in the pulp, no outbreak of the disorder occurred in the factory from which it was isolated, thus reaffirming the soundness of the cider-making methods specifically designed to prevent the growth of this bacterium. The characteristics of this isolate are compared with the two known species, namely, Zymomonas anaerobia and Z. mobilis and it is concluded that the new isolate is a strain of the former.

The ecology of the acetic acid bacteria has been studied at various stages of their association with cider manufacture. Of the 278 strains of bacteria isolated during the survey, 255 proved to be representative of 6 species of acetic acid bacteria. The remaining 23 strains included one example of the spoilage organism, Zymomonas anaerobia, but they were mostly ubiquitous soil bacteria which could not survive the low pH of apple juice and were only found associated with the early stages of cider making. The acetic acid bacteria were isolated in a sequential type of pattern. Those species which preferentially oxidize sugars were found at the early stages of processing when sugars abound, but these were replaced by the relatively more acid‐tolerant species, which are better equipped to oxidize alcohols, after the yeast fermentation had converted most of the sugar to ethanol.

An i n vitro association between cells of 8accharomyces cerevihae and 8Leuconostoc sp. has been demonstrated using the SCaMing electron microsoope. These organism are often naturally associated in fruit products and fermenting beverages such aa apple juice and cider.

Scanning electron microscopy has been used to study colony structures of four yeast species associated with cider making. A glutaraldehyde fixation technique is compared with direct observation of untreated specimens.

All methods of egg preservation aim to prevent the entry and growth of spoilage or pathogenic micro‐organisms which would make the egg unpalatable or dangerous to health. Although the contents of chickens' eggs are sterile on laying, the shell surface may be contaminated with many micro‐organisms — on average there may be 130,000 bacteria on the shell of an egg. Most of these organisms, which come from the nest litter or the bird's excreta, will spoil the egg but are not harmful to health, for example Pseudomonas fluorescens which causes ‘green rot’ and off‐odours if allowed to penetrate the egg and grow. Some of the contaminating organisms may be pathogenic, food‐poisoning bacteria such as Salmonella species, which are sometimes present in chicken droppings, but pathogens are very rare in chickens' eggs. Similar salmonellae have been implicated in numerous food‐poisoning outbreaks associated with duck eggs, as the aquatic environment of the duck encourages their growth and on no account should duck eggs be preserved.