Microbiological investigation on black crusts from open-air stone monuments of Bologna (Italy).

Samples of black crusts taken from open-air stone monuments in Bologna dating back to between the twelfth and the nineteenth century were considered. The microbiological test procedures isolated from a high number of chemoorganotrophic bacteria, each of the samples although it was expected to find chemo-lithotrophic (specially sulfur-oxidizing and nitrifying) bacteria on account of the great amounts of sulphur, carbon, nitrogen dioxides and ammonia in the air. Sporogenous and asporogenous species were found among the isolated bacteria: the first were recognized as Bacillus subtilis, Bacillus brevis, Bacillus licheniformis, Bacillus mycoides and Bacillus megaterium; the latter were Corynebacterium glutamicum, Actinomyces sp., Alcaligenes denitrificans subsp. denitrificans, Flavobacterium breve, Acinetobacter calcoaceticus, Enterobacter cloacae, Pseudomonas stutzeri. These species were differently associated in the samples studied with a frequency of more than sixty-four per cent. This finding leads us to believe that their presence in the black crusts is not occasional, but the result of an ecologically significant process of colonization. Although behavioural tests (solubilization of calcium carbonate, of calcium sulphate and marble dust) did not reveal lithic activity among the bacteria studied, one can presume that their behaviour in nature - as a more or less complex microbial consortium - can be totally different and exert a decomposing action with regard to several minerals, most of them acidify the media in which they develop.

Gram-positive cocci isolated from slaughtered poultry.

Gram-positive cocci were found in all meat samples of poultry slaughtered and processed for retail sale, at incidence rates ranging from 10(2) CFU/ml to 1.35 x 10(6) CFU/ml and a mode between 8 x 10(5) and 9 x 10(5) CFU/ml for 75% of the samples. The 93 isolated strains were identified as belonging to the following species: Enterococcus faecalis (48 strains), E. faecium (16), E. avium (7), E. durans (4), Aerococcus viridans (10), Streptococcus morbillorum (2), S. salivarius (1), S. sanguis (1), S. "milleri" (1), S. pneumoniae (1), S. acidominimus (1), and Gemella haemolysans (1). These species, which mainly colonize the intestinal tract, but may also be found in other parts of both the human and animal body, are pathogens or potentially such. Their presence is an indication of the fecal contamination of meat processed following gutting of slaughtered chickens (endogenous contamination). A count of the Gram-positive cocci and enterobacteria detected showed that enterococci were present in a far greater number than coliform bacteria.

Microbiological research on soft drinks: discolouring of natural-flavoured products.

The results of experiments testing the effects of yeasts, sunlight, and temperature on the food dyes tartrazine, ponceau 4R, indigotin and azorubin (used for colouring ginger soft drink) are reported. Light was found to exert a greater influence than heat, and yeasts growth hastened colour degradation. Yeasts assimilated to varying extent the colouring compounds and, when failing to do it, showed a certain power of adsorption by the no longer viable cells.

Antibiotic resistance among coliform bacteria isolated from carcasses of commercially slaughtered chickens.

A total of 322 coliform bacteria Escherichia coli, Enterobacter spp., Citrobacter spp., Klebsiella spp. and Serratia spp., were isolated from 50 carcasses of commercially slaughtered chickens. Their resistance to ampicillin, tetracycline, gentamicin, chloramphenicol, cephalotine, cotrimoxazole, nalidixic acid and nitrofurantoin, were determined. The most commonly found resistance was to tetracycline followed by cephalotine, cotrimoxazole and nalidixic acid. A large percentage of E. coli (41%) and Klebsiella spp. (38%) showed multiple antibiotic resistance.

[Alterations caused by yeasts in vegetable flavoured soft drinks: effects of the manufacturing water (author's transl)]. / Alterazione da blastomiceti delle bevande analcooliche a base di aromatizzanti vegetali: importanza dell'acqua impiegata

Possible sources of yeast pollutions of soft drinks added with vegetable flavours and the factors affecting their magnitude were examined. The greatest role is played by the minerals contained in the manufacturing water. Pasteurization is the most useful practice for their control.