Decimal reduction times (D-values) at cooking and autoclaving temperatures (80 to 120°C) of spores of Bacillus cereus ATCC 1479-8 in rice and milk (13% wt/vol) supplemented with nisin (25 μg/ml) were evaluated. The mean D-values at 97.8°C in cooked white rice, phosphate buffer (pH 7.0), and rice water (pH 6.7) were 3.62, 1.99, and 1.34 min, respectively. From 80 to 100°C, the mean reduction in D-values due to the addition of nisin to milk was 40%. The D-value at 110°C was ~0.86 min for milk (control) and milk with nisin. The z-values ranged from 7.32°C (phosphate buffer) to 10.37°C (milk control).

Industrial effluents from the pharmaceutical industry often contain high concentrations of phenolic compounds. The presence of "anthropogenic" organic compounds in the environment is a serious problem for human health; therefore, it merits special attention by the competent public agencies. Different methods have been proposed in the last two decades for the treatment of this kind of industrial residues, the most important of which are those utilizing absorption columns, vaporization and extraction, and biotechnological methods. Biofiltration is a method for the removal of contaminants present in liquid or gaseous effluents by the use of aerobic microorganisms, which are immobilized on solid or porous supports. Although several bacteria can utilize aromatic compounds as carbon and energy source, only a few of them are able to make this biodegradation effectively and with satisfactory rate. For this reason, more investigation is needed to ensure an efficient control of process parameters as well as to select the suited reactor configuration. The aim of this work is to provide an overview on the main aspects of biofiltration for the treatment of different industrial effluents, with particular concern to those coming from pharmaceutical industry and laboratories for the production of galenicals.

F e d -b a t c h ethanol f e r m e n t a t i o n tests of sugar cane blackstrap molasses were carried out at 32°C and p H 4.5-5.0, using pressed yeast as inoculum, and with no air supply. Two values of the fermentor filling-up time were adopted: 5 h and 7 h. The feeding rates obeyed equation F = F o ' e -K t , with K equal to 0.0, 0.2, 0.4, 0.6 and 0.8 h -1. The average yeast yields and the average yeast productivities increased up to 33°70 and 45%, respectively, while the ethanol yield (aver-age=76°70; standard d e v i a t i o n = 4 % ) was practically unaffected when K increased from 0 to 0.8 h -~.

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