Proteolytic potential of enzymes produced by candida parapsilosis and rhodotorula. Mucilaginosa isolated from liquid whey

The search for yeast with proteolytic activity that can be explored in technology and product innovation was the objective of this study to isolate and identify strains present in liquid whey and evaluate the proteolytic activity of isolates. From the isolated strains were selected for molecular identification, those with proteolytic activity. Verification of proteolytic activity was performed on milk agar and visualized by a translucent halo. Four strains belonging to two yeast species were identified as protease producers. Whey is promising in microbial sources of biotechnological interest and C. parapsilosis (ES01) and R. mucilaginosa (ES04) strains were good protease producers in commercial agar-like milk agar. These results indicate the proteolytic potentiality of strains isolated from whey.Fil: Monte, Aline Marques. Universidade Federal Do Piaui.; BrasilFil: Matos da Silva, Ana Karoline. Universidade Federal Do Piaui.; BrasilFil: Dourado Rodrigues, Aline Maria. Universidade Federal Do Piaui.; BrasilFil: Muratori Costa, Luciana. Universidade Federal Do Piaui.; BrasilFil: Sousa Santos, André Luis. Universidade Federal do Rio de Janeiro; BrasilFil: Gomes Abreu Bacelar, Rafael. Universidade Federal Do Piaui.; BrasilFil: de Sousa Ramos, Lívia. Universidade Federal do Rio de Janeiro; BrasilFil: Folmer Correa, Ana Paula. Universidade Federal de Roraima; BrasilFil: Brandelli, Adriano. Universidade Federal do Rio Grande do Sul; BrasilFil: Pereyra, Carina Maricel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Microbiología e Inmunología; ArgentinaFil: Sanches Muratori, Maria C.. Universidade Federal Do Piaui.; Brasi

Screening of aflatoxin B1 and mycobiota related to raw materials and finished feed destined for fish

The aim of the present study was to determine fungal genera, Aspergillus, Pénicillium and Fusarium species and aflatoxin B1 contamination from raw materials and finished feed intended for fish farm localized in Piaui, Brazil. Aspergillusflavus and P. citrinum were isolated with a high relative density from all samples. In general, a high percent of samples exceeded the levels proposed as feed hygienic quality limits (CFU g-1) according to Good Manufacture Practice. Aflatoxin B1 was analyzed by enzyme-linked immunosorbent assay. All raw materials and finished feed showed aflatoxin B1 levels. Although in this study AFB1 levels below recommended limits (20 μg kg-1) were found, it is important to emphasize the feed intake with toxin in low concentrations along time, since it produce chronic deleterious effects in animal production. This fact requires periodic monitoring to prevent the occurrence of chronic aflatoxicosis in aquaculture, to reduce the economic losses and to minimize hazards to animal health