Chemical, ecotoxicological, cytotoxic, and mutagenic evaluation of gelling agents used in the production of 70% alcohol gel.

With COVID-19, there has been an increase in the use of gelling agents for hand sanitizer production, and as a result, the release of this product into wastewater could induce impacts and adverse reactions in living organisms. Thus, ecotoxicological and cytotoxicological assessments of gelling agents with test organisms from different trophic levels are necessary to assess their environmental safety. For this, seven cellulose-based gelling agents and a polyacrylic acid derivative (C940) were selected for tests with Artemia salina. The most toxic agent was tested on Allium cepa to assess cytotoxicity. The volatile compounds of the gelling agents were analyzed. Cellulose-based gelling agents were not considered toxic according to their LC50, but C940 presented moderate toxicity to A. salina and cytotoxicity to Allium cepa, but without mutagenicity. In addition, C940 contained cyclohexane as a volatile compound. Thus, cellulose-based gelling agents are better environmental options than carbomer for 70% alcohol gel sanitizer.

Behavior of deteriogenic fungi in aviation fuels (fossil and biofuel) during simulated storage.

Biofuels are expected to play a major role in reducing carbon emissions in the aviation sector globally. Farnesane ("2,6,10-trimethyldodecane") is a biofuel derived from the synthesized iso-paraffin route wich can be blended with jet fuel; however, the microbial behavior in farnesane/jet fuel blends remains unknown. The chemical and biological stability of blends should be investigated to ensure they meet the quality requirements for aviation fuels. This work aimed at evaluating the behavior of two fungi Hormoconis resinae (F089) and Exophiala phaeomuriformis (UFRGS Q4.2) in jet fuel, farnesane, and in 10% farnesane blend during simulated storage. Microcosms (150-mL flasks) were assembled with and without fungi containing Bushnell & Haas mineral medium for 28 days at a temperature of 20±2°C. The fungal growth (biomass), pH, surface tension, and changes in the fuel's hydrocarbon chains were evaluated. This study revealed thatthe treatment containing H. resinae showed a biomass of 19 mg, 12 mg, and 2 mg for jet fuel, blend, and farnesane respectively. The pH was reduced from 7.2 to 4.3 observed in jet fuel treatment The degradation results showed that compounds with carbon chains between C9 and C11, in jet fuel, and blend treatments were preferably degraded. The highest biomass (70.9 mg) produced by E. phaeomuriformis was in 10% farnesane blend, after 21 days. However, no significant decrease was observed on pH and surface tension measurements across the treatments as well as on the hydrocarbons when compared to the controls. This study revealed that farnesane neither inhibited nor promoted greater growth on both microorganisms.

Potential use of a thermal water cyanobacterium as raw material to produce biodiesel and pigments.

Global energy demand is increasing every day and most is still derived from non-renewable sources. Therefore, sustainable alternatives are sought to produce biofuels, such as biodiesel. Several studies have demonstrated the potential of microalgae and cyanobacteria to produce biodiesel and pigments. These pigments, such as lutein and astaxanthin, have a high commercial value and can economically support the production of biodiesel. However, few studies have explored the potential of cyanobacteria collected in thermal water. In these microorganisms, both biomass and metabolites production can be altered by the culture form. Thus, a cosmopolitan filamentous cyanobacterium (Geitlerinema amphibium) from thermal water was collected and isolated to evaluate its potential to produce fatty acids, biodiesel, and pigments in two culture media. G. amphibium was cultured in WC (Wright's Cryptophyte) and BBM (Bold's Basal Medium) media. Thermal stress (40 °C for 48 h) was applied to the medium, which generated higher productivity of the biomass in BBM. The cyanobacterium contained higher biodiesel content in the WC medium and higher pigment content in the BBM medium. Thermal stress increased the biodiesel content by 350%, but decreased pigment content. Two pigments with high commercial value (astaxanthin and lutein) were identified. G. amphibium produced up to 2.74 mg g-1 of astaxanthin and 5.49 mg g-1 of lutein, which is seven times more lutein than Marigold, currently the main raw material used commercially. Therefore, G. amphibium has the potential to produce biodiesel, astaxanthin, and lutein concomitantly.

Efeito do leite bovino na cicatrização de feridas cutâneas em ratos / Effect of milk cattle in the healing of skin wounds in rats

Verificar o efeito do leite bovino cru congelado e do leite pasteurizado eresfriado na cicatrização de feridas cutâneas em ratos. Métodos: Foram usados 30 ratos adultos, machos da linhagem Wistar, distribuídos em 03 grupos com 10 animais cada: o grupo 01 foi tratado com solução salina a 0,9%; o grupo 02 tratado com leite bovino cru congelado e o grupo 03 com leite bovino pasteurizado e resfriado. Usou-se topicamente na ferida, 0,1ml da solução a 0,9% e nos dois tipos de leites estudados, três vezes ao dia. A avaliação da lesão foi realizada no 3º, 7º e 11º dia do pósoperatório.Diariamente era observado de forma macroscópica, o crescimento ou nãode pelos ao redor das feridas. Resultados: As medidas digitais da área da injúria e as do paquímetro revelaram que o leite bovino cru, apresentou efeito estatisticamente significante na retração da lesão e no crescimento de pelos. Conclusão: O uso tópico de leite bovino cru congelado cicatriza, mais rapidamente, feridas cutâneas em ratos e o leite bovino pasteurizado e resfriado não apresenta este efeito. O leite bovino cru influencia a recuperação da pelagem de ratos machos Wistar.

To determine the effect of frozen raw bovine milk and pasteurized milk and cooled in the healing of skin wounds in rats. Methods: We used 30 adult rats, male Wistar strain, divided into 03 groups with 10 animals in each: group 01 was treated with saline solution to 0.9%, the group 02 was treated with raw frozen bovine milk and group 03 was treated withbovine pasteurized and cooled milk. It was used topically in the wound, 0.1 ml of a 0.9% saline solution and the two types of milk studied during three times a day. The evaluation of the lesion was performed at 3rd, 7th and 11th days post-operatively. Daily it was observed in a macroscopicway, the absence or not of hair growth around the wound. Results: The measures of the digital area of injury and the caliper showed that raw bovine milk showed statistically significant effect on the shrinkage of the lesion and the growth of hair. Conclusion: The topical use of raw frozenbovine milk heals faster the skin wounds in rats, and pasteurized and cooled bovine milk it has no the same effect. The raw bovine milk influences the recovery of hair of male Wistar rats.