Abstract Bisphenol A is an endocrine interfering compound, produced and used on a large scale worldwide. Chemical and biologic methods can be used to remove it from the environment. Biological methods are considered less costly, safer and, according to green chemistry definitions, an environmentally correct method. Considering the use of a crude enzyme broth, without any downstream process, the costs could be mostly reduced. Thus, the removal of bisphenol A by Pleurotus sajor-caju crude enzyme broth was investigated. Initially, the agro-industrial wastes were characterized and, the composition of the culture medium and the bioreactor culture conditions were defined. The enzyme produced in the highest concentration was characterized and the crude broth used in the bisphenol A removal assays. The OXI45 culture medium presented the highest laccase activity (1,850.7 U L-1, 350 rpm). Greater laccase stability was observed at 20 - 40 oC and pHs 5 - 7. Vanillin and ferulic acid (considered mediator compounds) were identified in the crude broth, probably helping on the obtention of the high value of removal effectiveness (0.052 mg U-1 h-1). The results indicate the potential use of the Pleurotus sajor-caju crude enzyme broth to obtain an enzymatic formulation for application in the environmental area.

ABSTRACT Fungi of Pleurotus genus have attracted a great interest due to their medicinal properties such as anti-inflammatory, antimicrobial and antitumor. These properties are attributed mainly to polysaccharides synthesized by Pleurotus. This work aimed to study the mycelial growth of P. ostreatus in submerged culture, evaluating the influence of the initial concentration of substrate (20 and 40 g/L of glucose) and the pH (4 and 6) on kinetic parameters of production of biomass. The effectiveness of different doses (10, 30 and 50 mg/kg) of a mycelium polysaccharide fraction extracted from P. ostreatus in reducing Sarcoma 180 development in mice was also verified. In the range of this study, maximum concentration of mycelial biomass (about 12.8 g/L) was obtained using 40.0 g/L of glucose, at pH 4.0. The total biomass productivity (Px) was not significantly affected by substrate concentration and pH, reaching values of 0.034 g/L.h. Sarcoma 180 tumor weight was reduced in 74.1, 75.5 and 53.7% when 10, 30 and 50 mg/kg were administered, respectively. These results show the high antitumor potential of intracellular polysaccharide fraction of mycelial biomass of P. ostreatus, particularly at lower doses of 10 and 30 mg/kg.

A produção de xylitol por Candida parapsilosis foi investigada em regime de batelada alimentada, usando substratos açucarados de composição simples (xilose) ou composta (xilose e glicose). A presença de glicose no meio induziu a formação de etanol como metabólito secundário. A suplementação fracionada do meio de alimentação numa concentração fixa de açúcar não resultou em aumento da produtividade em relação àquela alcançada em batelada simples.

Xylitol production by Candida parapsilosis was investigated under fed-batch cultivation, using single (xylose) or mixed (xylose and glucose) sugars as substrates. The presence of glucose in the medium induced the production of ethanol as secondary metabolite and improved specific rates of growth, xylitol formation and substrate consumption. Fractionated supply of the feed medium at constant sugar concentration did not promote any increase on the productivity compared to the single batch cultivation.

Candida guilliermondii FTI 20037 was grown on a mixed substrate comprising glucose and xylose. Inocula were grown using xylose or glucose as carbon source. Results showed that xylose utilization was delayed until glucose was utilized. Inoculum prepared on glucose showed a lag phase in xylose consumption. Cell mass production was higher when glucose was utilized during fermentation.