Production of Enriched Sporidiobolus sp. Yeast Biomass Cultivated on Mixed Coffee Hydrolyzate and Fat/Oil Waste Materials

One of the most addressed topics today is the transfer from a linear model of economics to a model of circular economics. It is a discipline that seeks to eliminate waste produced by various industries. The food industry generates huge amounts of waste worldwide, particularly the coffee industry, and related industries produce millions of tons of waste a year. These wastes have potential utility in biotechnology, and in the production of energy, fuels, fertilizers and nutrients, using green techniques such as anaerobic digestion, co-digestion, composting, enzymatic action, and ultrasonic and hydrothermal carbonization. This work is focused on the biotechnological use of processed spent coffee grounds (SCG) and waste fat/oil materials by some Sporidiobolus sp. carotenogenic yeasts in the model of circular economics. The results show that selected yeast strains are able to grow on SCG hydrolysate and are resistant to antimicrobial compounds present in media. The most productive strain Sporidiobolus pararoseus CCY19-9-6 was chosen for bioreactor cultivation in media with a mixture of coffee lignocellulose fraction and some fat wastes. Sporidiobolus pararoseus CCY19-9-6 was able to produce more than 22 g/L of biomass in mixture of SCG hydrolysate and both coffee oil and frying oil. The combined waste substrates induced the production of lipidic metabolites, whereby the production of carotenoids exceeded 5 mg/g of dry biomass. On media with coffee oil, this strain produced high amounts of ubiquinone (8.265 ± 1.648 mg/g) and ergosterol (13.485 ± 1.275 mg/g). Overall, the results prove that a combination of waste substrates is a promising option for the production of carotenoid- and lipid-enriched yeast biomass.

Microencapsulation by lyophilization of natural carotenoids using different wall materials/ Microencapsulação por liofilização de carotenoides naturais utilizando diferentes materiais de parede

Due to the biological importance of carotenoids, several works have been developed aiming for the reduction of carotenoid degradation, and one notable proposed alternative has been the formation of microcapsules. Therefore, the aim of the current paper was the microencapsulation of carotenogenic extracts from Rhodotorula mucilaginosa and Sporidiobolus pararoseus by a lyophilization method utilizing gum arabic, xanthan gum, sodium alginate and soy protein-like wall materials. The gum arabic showed the greatest efficiency of encapsulation for the R. mucilaginosa (66.3±0.8 %) and S. pararoseus (91.4±0.9 %) carotenogenic extracts, while the soy protein showed the lowest efficiency of encapsulation (40.7±1.1 % for R. mucilaginosa and 68.5±1.5 % for S. pararoseus). Scanning electron micrographs (SEM) showed irregular structure formation that was independent of the material utilized for the encapsulation. In this way, it was possible to observe that the wall materials directly affect the encapsulation efficiencies, morphology, and thermal behavior of the capsules of natural carotenoids.

Antigenotoxic Effects and Possible Mechanism of Red Yeast (Sporidiobolus pararoseus) on Aflatoxin B1-Induced Mutagenesis

Red yeast (Sporidiobolus pararoseus), obtained from glycerol waste in the biodiesel process, has been used as a mycotoxin sorbent in some agricultural products. This study focused on the antigenotoxic effects of red yeast on aflatoxin B1 (AFB1)-induced mutagenesis, using a Salmonella mutation assay and a rat liver micronucleus test. Red yeast was sequentially extracted to obtain hexane, acetone, hot water, and residue fractions. Carbohydrates were mainly found in hot water extract (HWE), while proteins were observed in the residue fraction. The amount of lycopene in hexane extract (HE) was higher than the amount of β-carotene in HE. All red yeast extracts were not mutagenic in the Salmonella typhimurium strains TA98 and TA100 under the presence and absence of metabolic activation. Among the extracts obtained from red yeast, HE presented the strongest antimutagenicity against AFB1-induced mutagenesis in both strains, but HWE did not show any antimutagenicity. The oral administration of red yeast, HE, and HWE for 28 days was further investigated in rats. These extracts did not induce micronucleated hepatocytes. Furthermore, they modulated the activities of some detoxifying enzymes but did not alter the activities of various cytochrome P450 isozymes. Notably, they significantly decreased hepatic micronucleus formation in AFB1-initiated rats. HE altered the activity of hepatic glutathione-S-transferase but did not affect its protein expression. Taken together, the antigenotoxicity of red yeast against AFB1-induced mutagenesis might be partly due to the modulation of some detoxifying enzymes in AFB1 metabolism. β-Carotene and lycopene might be promising antigenotoxic compounds in red yeast.

Carotenoids in Sporidiobolus pararoseus ameliorate diabetic nephropathy in mice through attenuating oxidative stress

Diabetic nephropathy (DN) is the major life-threatening complication of diabetes, and oxidative stress takes part in its initiation and development. This study was performed to evaluate the effects of carotenoids from Sporidiobolus pararoseus (CSP) on the renal function and oxidative stress status of mice with streptozotocin (STZ)-induced DN. The results indicated that CSP significantly attenuated symptoms of STZ-induced DN shown by decreased fasting blood glucose, reduced urine volume, urine albumin, serum creatinine and serum urea nitrogen, and improved kidney histological morphology. Furthermore, biochemical analysis of serum and kidney revealed a marked increase in oxidative stress of DN mice as evidenced by reduced total antioxidant capacity (T-AOC), decreased activity of antioxidant enzyme -superoxide dismutase (SOD) and increased level of malondialdehyde (MDA). However, treatment with CSP improved oxidative stress status in DN mice as compared with the mice in model group. Exploration of the potential mechanism validated that CSP ameliorated the oxidative stress status in DN mice by activating the expressions of Nrf2, NQO-1, HO-1, GST and CAT in kidney. These data revealed that CSP may retard the progression of DN by ameliorating renal function, improving the oxidative stress status and activating the Nrf2/ARE pathway.