No abstract

One of the most important classes of nutritional biomolecules is the oleaginous compounds group, which specially includes the oil-lipids, the carotenoids and the fatty acids. These biocompounds present a wide range of industrial applications because their ability to act as an energy source, antioxidants and metabolic agents for the human body. Therefore, the food industry, mainly focusing on food supplementation, is always searching for new sources of them. In this context, the present study evaluated the total lipids, carotenoids and fatty acids simultaneous production by the Rhodotorula mucilaginosa CCT3892 yeast, using residual sugarcane molasses as carbon source. The results obtained demonstrated that the cultivation of yeast in molasses medium (MC) produced the same content of total lipids and carotenoids (16.50% ± 0.68% and 0.053 ± 0.001 mg g-1, respectively) as the obtained from a synthetic medium (SC) (15.36% ± 1.36% and 0.051 ± 0.001 mg g-1 0.005). Concerning the fatty acids biosynthesis, the MC cultivation generated the most interesting profile once it presented a greater content of oleic acid (74.05%), an unsaturated compound with high nutritional value. The cultivation carried out with the molasses and yeast extract supplementation (MYEC) did not provide an improvement in microbial oil production, what indicated that in this condition there was a predominance of others sorts of substrate metabolization by the yeast cells, as confirmed by the microbial kinetics study.

The use of β-galactosidase in food products has been a major focus of the industry. Therefore, the development of effi cient and inexpensive methodologies to purify it is essential. Thus, this study aimed to recover the enzyme β-galactosidase (β-gal) by ion-exchange chromatography in a fi xed-bed column. Batch adsorption tests were performed using four types of adsorbents. The β-gal adsorption capacity in batch mode using Streamline DEAE resin presented the best performance, with a retention capacity of 18.77 ± 0.14 U/g at pH 6.0. A 2 2 experimental design was applied to optimize the β-gal recovery using an AKTA Start system, evaluating the ionic strength and the pH as process parameters. The results showed that ionic strength exerted a greater infl uence on fold purifi cation (FP). The β-gal fraction in elution using 0.1-0.4 M of NaCl showed a yield of 51.65 ± 0.17% and FP of 2.00 ± 0.43. Electrophoresis confi rmed the β-gal recovery, where an evident band with a molecular weight between 60 and 120 kDa was observed. These results point to the recovery of a stable β-gal of K. lactis with potential industrial applications.

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Trichoderma reesei is a fungus that has been widely explored for its potential as cellulolytic enzyme producer and has diverse industrial applications. However, obtaining the enzymes is still considered a costly and, sometimes, inefficient process. This study aimed to produce endoglucanases by cultivating T. reesei (CCT-2768) in solid state fermentation, using cashew apple bagasse (CAB), sugarcane bagasse (SCB) and green coconut fiber (GCF) residues as substrates. The influence of moisture and pH on enzyme production was evaluated using a factorial design. T. reesei showed viability for producing endoglucanases in all of the three lignocellulosic residues tested, with maximum activity (2.29 ± 0.01 U/g) observed when cultivated in the SCB substrate and using moisture of 60% and pH 5.5. Thus, use of lignocellulosic residues proves to be a viable alternative for producing endoglucanases by cultivation of Trichoderma reesei, which contributes to the recycling of waste and the reduction of environmental impacts.