Abstract The cosmetics industry searches for new products with sustainable, natural and non-toxic characteristics. Levan is a microbial exopolysaccharide composed of fructose units with β-2,6-glycoside bonds. Due to its biological properties, levan has a wide range of applications in cosmetics and pharmaceuticals industry. The effects of levan can be improved by its combination with biocompatible actives such as plant-derived compounds and vitamins resulting in a multifunctional cosmetic formulation. Thus, the aim of this study was to develop a new biocosmetic gel-anionic type containing 1 % of levan and plant-derived compounds, such as Aloe vera extract and avocado oil and vitamin E, using simplex lattice mixtures design. According to the statistical analyses, the concentrations to obtain a cosmetic with maximum antioxidant activity (76%), hydration capacity (98.37%) and spreadability (767.30 mm2), would be 10% (0.1 mL) of Aloe vera, and 90% (0.9 mL) of avocado oil. Cosmeceutical formulations showed good stability and did not show phase separation or visible changes being classified as normal. The development of innovative and sustainable cosmetic formulations, with natural, vegan and non-toxic molecules is of great importance for cosmetic industry.

Abstract Sophorolipids are glycolipids that have natural antimicrobial properties and present great potential in the pharmaceutical field. The present study aimed to produce sophorolipids from Candida bombicola using a chicken fat-based medium and evaluate the antimicrobial activity against Gram-negative (Proteus mirabilis, Escherichia coli, Salmonella enterica subsp. enterica) and Gram-positive bacteria (Enterococcus faecium, Staphylococcus aureus and Streptococcus mutans). The production of sophorolipids reached 27.86 g L-1. Based on the structural characterization, 73.55% of the sophorolipids present a mixture of acidic monoacetylated C18:2 and lactonic diacetylated C16:0, and 26.45% were present in the diacetylated C18:1 lactonic form. Bacteria submitted to sophorolipid exposure showed a reduction in viability at doses of 500 μg mL-1 and 2,000 μg mL-1 against Gram-positive and Gram-negative bacteria, respectively. These results suggest that sophorolipids produced in chicken fat medium may be used as antimicrobial agents to prevent or eliminate contamination by different pathogens.

Abstract The aims of this work were to produce hyaluronic acid (HA) by Streptococcus zooepidemicus ATCC 39920 in a low cost sugarcane molasses fermentation medium and to employ the produced HA to obtain films blends based on polyvinyl alcohol (PVA). The films were produced using solution casting method and they were characterized according to their microstructure, mechanical and barrier properties. HA was added in different concentrations (0, 5, 10 and 15% (w/w)), and glycerol was used as a plasticizer (25 g/100 g solids). All formulations resulted in easily manipulated films with good appearance. The addition of HA on PVA films increased their thermal stability, solubility, swelling index, water vapor permeability and elongation. Microbial HA sample combined with PVA showed to be a promising material to biomedical application, and an addition between 5 and 10% (w/w) was sufficient to improve PVA films properties.

Levan is an exopolysaccharide of fructose primarily linked by β-(2→6) glycosidic bonds with some β-(2→1) branched chains. Due to its chemical properties, levan has possible applications in both the food and pharmaceutical industries. Bacillus subtilis is a promising industrial levan producer, as it ferments sucrose and has a high levan-formation capacity. A new strain of B. subtilis was recently isolated from Japanese food natto, and it has produced levan in large quantities. For future pharmaceutical applications, this study aimed to investigate the effects of levan produced by B. subtilis Natto, mainly as potential hypoglycemic agent, (previously optimized with a molecular weight equal to 72.37 and 4,146 kDa) in Wistar male rats with diabetes induced by streptozotocin and non-diabetic rats and to monitor their plasma cholesterol and triacylglycerol levels. After 15 days of experimentation, the animals were sacrificed, and their blood samples were analyzed. The results, compared using analysis of variance, demonstrated that for this type of levan, a hypoglycemic effect was not observed, as there was no improvement of diabetes symptoms during the experiment. However, levan did not affect any studied parameters in normal rats, indicating that the exopolysaccharide can be used for other purposes.

Zymomonas mobilis produz o poliálcool sorbitol como principal subproduto. Sua formação é atribuída principalmente a sua função A produção de sorbitol foi avaliada através de um planejamento fatorial completo utilizando as variáveis concentração de sacarose, concentração de maltose e tempo de cultivo. A adição de açúcares causou um aumento na produção de sorbitol até a concentração de 300g/L, porém decréscimos na produção de sorbitol foram observados a concentrações superiores a esta. Aumento no tempo de fermentação foi estatisticamente significativo para aumentos da produção de sorbitol, porém pequeno aumento foi observado de 12 para 36 horas de cultivo.

The objective of the present work was to study the variation on the sorbitol production in relation to the concentration of sugars, (metabolizable or not) and the cultivation time. A full factorial design was used considering the factors such as sucrose and maltose concentration and cultivation time. The addition of sugars caused increases on the sorbitol production up to the concentration of 300g/L however, decreases on the sorbitol production were observed when the concentration reached values above this. Increasing the time of fermentation was statistically significant to sorbitol production, however, little increase the production was noticed after 36h.

Neste trabalho investigou-se o efeito de pulsos de rafinose e ultra-som, na liberação de invertase de Saccharomyces cerevisiae livre e imobilizado em Luffa cylindrica. A cultura de células livres foi submetida a pulso de rafinose 2% e irradiada por 2 min, nas taxas de diluição 0,12 e 0,46 h-1. A cultura de células imobilizadas foi submetida a pulso de rafinose e irradiada por 1, 2 e 4 min, em taxa de diluição 0,10 h-1. Em células imobilizadas, o pulso de rafinose aumentou a atividade invertásica de 5,38 para 7,27 U/mg. Entretanto a aplicação do ultra-som, em cultivo de células livres na taxa de diluição 0,12 h-1, obteve-se os melhores resultados. A atividade variou de 25,08 para 29,38 U/mg, enquanto que o aumento em células imobilizadas foi de 5,22 para 9,70 U/mg, quando sonicadas por 2 min. Esses resultados demonstram que a aplicação de ultra-som, em cultivo contínuo de células livres, pode ter um grande potencial de aplicação em processos biotecnológicos.

This study investigated the effect of raffinose and ultrasound pulses on invertase release from free S. cerevisiae and S. cerevisiae immobilized in Luffa cylindrica. The free cell culture was submitted to 2% raffinose pulse and irradiated for 2 minutes at 0.12 and 0.46 h-1 dilution rates. The immobilized cell culture was submitted to raffinose pulse and irradiated for 1, 2 and 4 minutes, at 0.10 h-1 dilution rate. In immobilized cells, the raffinose pulse increased the invertase activity from 5.38 to 7.27 U/mg. Ultrasound application in free cell culture at the 0.12 h-1 dilution rate gave the best results. The activity varied from 25.08 to 29.38 U/mg while the increase in immobilized cells was from 5.22 to 9.70 U/mg when sonicated for two minutes. These results showed that ultrasound application in continuous culture could have great potential for application in biotechnological techniques.

A bactéria Zymomonas mobilis, apresenta potencial para produção de sorbitol quando crescida em meio com alta concentração de açúcar. O sorbitol produzido é acumulado no periplasma da bactéria para conter os efeitos prejudiciais da elevada pressão osmótica, que resulta pela ação da enzima invertase, que promove hidrólise da sacarose. A conversão da sacarose em glicose e frutose aumentando a osmolaridade do meio. Entretanto, um aumento excessivo na pressão osmótica pode inibir a produção de sorbitol pela bactéria. Este trabalho empregou invertase de Saccharomyces cerevisiae nos meios de fermentação com sacarose a 200 e 300 g.L-1. A produção de sorbitol no meio com sacarose a 200 g.L-1 foi de 42,35 g.L-1 e 38,42 g.L-1 com e sem tratamento com invertase respectivamente. No meio com 300 g.L-1 sem tratamento, a produção foi de 60,42 e com tratamento 19,14 g.L-1. Estes resultados indicaram que a elevação excessiva da pressão osmótica, pela adição de invertase levou a uma diminuição significativa na produção de sorbitol pela bactéria Zymomonas mobilis.

The bacterium Zymomonas mobilis presents potential for sorbitol production when grown in culture medium with high sugar concentration. Sorbitol is produced and accumulated in the periplasma of the bacterium to protect the cells from the harmful effects of high osmotic pressure that results from the action of invertase on sucrose. The conversion of sucrose into glucose and fructose increases the osmolarity of the medium. However, an excessive increase in the osmotic pressure may decrease the sorbitol production. In this work Saccharomyces cerevisiae invertase was added two media containing sucrose 200 and 300 g.L-1. Sorbitol production in sucrose at 200 g.L-1 was 42.35 and 38.42 g.L-1, with and without the invertase treatment, respectively. In the culture medium with 300 g.L-1 sucrose, production reached 60.4 g.L-1 and with invertase treatment was 19.14 g.L-1. These results indicated that the excessive rise in osmotic pressure led to a significant decrease in sorbitol production by the Zymomonas mobilis bacterium in the sucrose medium treated with invertase.