The production of volatile fatty acids (VFAs), intermediates in the anaerobic degradation process of organic matter from waste water, was evaluated in this work. A batch reactor was used to investigate the effect of temperature, and alkalinity in the production of VFAs, from the fermentation of industrial cassava waste water. Peak production of total volatile fatty acids (TVFAs) was observed in the first two days of acidogenesis. A central composite design was performed, and the highest yield (3400 mg L(-1) of TVFA) was obtained with 30°C and 3 g L(-1) of sodium bicarbonate. The peak of VFA was in 45 h (pH 5.9) with a predominance of acetic (63%) and butyric acid (22%), followed by propionic acid (12%). Decreases in amounts of cyanide (12.9%) and chemical oxygen demand (21.6%) were observed, in addition to the production of biogas (0.53 cm(3) h(-1)). The process was validated experimentally and 3400 g L(-1) of TVFA were obtained with a low relative standard deviation.

This research aimed to microencapsulate Saccharomyces boulardii using an experimental design 23 to evaluate vegan and vegetarian wall materials, rice protein, and maltodextrin in different proportions, drying temperature, and feed flow. The microcapsules were characterized by encapsulation yield, moisture content, scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, and survivability rate in simulated gastric solution and during storage under refrigeration. The best encapsulation yield of S. boulardii was 79.88 ± 1.35% at maltodextrin: rice protein of 25:75%, 80°C, and feed flow rate 0.75 L h−1, with survivability rate in simulated gastric solution at pH 3 of 83% in 3 h, and stability during storage in 20 days at 4 ± 1°C of 71.6%. Therefore, these wall materials are efficient to microencapsulate and preserve S. boulardii by spray‐drying, protecting the cells in gastrointestinal conditions, which may be applied in functional foods and beverages, dietary supplements, or animal feed. Novelty impact statement Microencapsulating Saccharomyces boulardii through spray‐drying enabled its preservation and the novelty is the use of plant‐derived proteins to protect the cells as an alternative for vegetarian and vegan consumers. The resulting product can be added to functional foods and beverages, dietary supplements, or animal feed.

Resumo: Este trabalho teve como objetivo utilizar fontes renováveis de carbono para crescimento de Cupriavidus necator visando à produção de poli (3-hidroxibutirato) com menor custo, utilizando como suplementos resíduos provenientes das indústrias processadoras de alimentos tais como bagaço de mandioca e soro de queijo e uma matéria-prima também renovável, o óleo de soja. Os cultivos foram realizados seguindo um planejamento experimental 2³, visando obter nesta etapa a melhor condição de crescimento com os suplementos testados. Os resultados obtidos através do planejamento experimental mostraram que não houve resultados significativamente diferentes, indicando que a utilização de qualquer um destes três suplementos (hidrolisado de bagaço de mandioca, soro de queijo e óleo de soja) não influencia a resposta. Palavras-chave: Poli (3-hidroxibutirato), Cupriavidus necator, suplementação.Abstract: This study aimed to use alternative carbon sources for Cupriavidus necator growth aimed at producing poly (3-hydroxybutyrate) at a lower cost, using supplements like waste from food processing industries such as cassava bagasse and cheese whey and renewable raw material, the soybean oil. The cultures were carried out using an experimental design 2 3 , to obtain the best condition at this stage of growth with the supplements tested. The results obtained from the experimental design showed no significant results, indicating that the use of any of these three supplements (cassava bagasse hydrolysates, milk whey, and soy oil) did not influence the response.

Saccharomyces boulardii viable cells have probiotic action. This study aimed to evaluate the effect of aeration on the production of S. boulardii viable cells in liquid cultivation medium with different initial glucose concentrations. Yeast has grown on yeast extract peptone dextrose medium with or without aeration (2 Lar min-1 to obtain 30 ± 1% of oxygen) and different initial glucose concentrations (20, 40 and 60 g L-1). The viable cells were determined by serial dilution method and glucose concentration was determined by 3-5 dinitrosalicylic acid. The number of viable cells changed from 7.54 ± 0.04 to 7.77 ± 0.02 log of CFU mL-1 when glucose increased from 20 to 60 g L-1, respectively. The aeration of the cultivation medium increased the number of viable cells from 7.78 ± 0.04 to 8.27 ± 0.04 log of CFU mL-1 in the cultivation medium with 40 g L-1 glucose. The yeast biomass was ~3 times greater than 60 g L-1 glucose with aeration when compared to cultivation medium with 20 g L-1 glucose without aeration. Thus, the glucose increase and the cultivation medium aeration increment S. boulardii production and viability.