RESUMO
Thermoactinomyces thalpophilus produced a raw-starch digesting amylase (RSDA) when grown on both cereal and tuber starches. Glucose, maltose and glycerol repressed enzyme production. Highest activity was recorded on rice starch (39 U ml(-1)). Considerable variability existed in the effectiveness of nitrogenous nutrients to stimulate expression of RSDA. Multiple pH optima for RSDA production and activity suggests enzyme heterogeneity.
RESUMO
When microbiological analyses were conducted on 90 samples of soft drinks representing 30 different products commercially available in Nigeria, contaminants were detected in 50% of them. The isolates were mainly saprophytic and non-pathogenic: Bacillus spp. (35%), Lactobacillus spp. (26%), Pediococcus spp. (6%), Staphylococcus epidermidis (6%) and Micrococcus spp. (3%) accounted for the bacterial isolates while Aspergillus niger (6%) and Saccharomyces spp. (16%) accounted for the fungal isolates.