Research background. Microbial β-fructofuranosidases are widely employed in food industry to produce inverted sugar or fructooligosaccharides. In this study, a newly isolated Aspergillus carbonarius PC-4 strain was used to optimize the β-fructofuranosidase production under a cost-effective process and the sucrose hydrolysis was evaluated to produce inverted sugars. Experimental approach. Optimization of nutritional components of culture medium was carried out using Simplex Lattice mixture design for 72 h and 120 h at 28 ˚C. One-Factor-at-a-time methodology was used to optimize the physicochemical parameters. Crude enzyme was used for sucrose hydrolysis at different concentrations. Results and conclusions. The optimized condition of enzyme production was pineapple crown waste (1.3 %, m/V) and yeast extract (0.3 %, m/V) for 72 h (9.4 U/mL), obtaining R² 91.85 %, R² adjusted 85.06 %, highest F value (13.52) and low p-value (0.003). One-factor-at-a-time used for optimizing the physicochemical conditions showed optimum temperature (20 ˚C), pH (5.5), agitation (180 rpm) and time-course (72 h) with an increase of 3.0-folds for enzyme production. The invertase-induced sucrose hydrolysis showed the maximum yield (3,451.7 µmols of reducing sugars) using 10 % of initial sucrose concentration. Higher sucrose concentrations caused inhibition of invertase activity, possibly due to saturation of substrate or formation of sucrose aggregates making it difficult for the enzyme to access sucrose molecules within the created clusters. So, a cost-effective method was developed for the invertase production using agroindustrial waste and the enzyme produced can be used efficiently for inverted sugar production at high sucrose concentration. Novelty and scientific contribution. This study presents an efficient utilization of pineapple crown wastes to produce invertase by a newly isolated Aspergillus carbonarius PC-4 strain. This enzyme exhibited a good potential for invert sugar production at high initial sucrose concentration, which is interesting for industrial applications.

Polyhydroxyalkanoate (PHA) bioplastic was synthesized by Burkholderia glumae MA13 from carbon sources and industrial byproducts related to sugarcane biorefineries: sucrose, xylose, molasses, vinasse, bagasse hydrolysate, yeast extract, yeast autolysate, and inactivated dry yeast besides different inorganic nitrogen sources. Sugarcane molasses free of pre-treatment was the best carbon source, even compared to pure sucrose, with intracellular polymer accumulation values of 41.1–46.6% cell dry weight. Whereas, xylose and bagasse hydrolysate were poor inducers of microbial growth and polymer synthesis, the addition of 25% (v/v) sugarcane vinasse to the culture media containing molasses was not deleterious and resulted in a statistically similar maximum polymer content of 44.8% and a maximum PHA yield of 0.18 g/g, at 34°C and initial pH of 6.5, which is economic and ecologically interesting to save water required for the industrial processes and especially to offer a fermentative recycling for this final byproduct from bioethanol industry, as an alternative to its inappropriate disposal in water bodies and soil contamination. Ammonium sulfate was better even than tested organic nitrogen sources to trigger the PHA synthesis with polymer content ranging from 29.7 to 44.8%. GC-MS analysis showed a biopolymer constituted mainly of poly(3-hydroxybutyrate) although low fractions of 3-hydroxyvalerate monomer were achieved, which were not higher than 1.5 mol% free of copolymer precursors. B. glumae MA13 has been demonstrated to be adapted to synthesize bioplastics from different sugarcane feedstocks and corroborates to support a biorefinery concept with value-added green chemicals for the sugarcane productive chain with additional ecologic benefits into a sustainable model.

This study aimed to optimize the production of xylanase, under submerged conditions using Fusarium oxysporum. Firstly, it was carried out the selection of the best source of carbon from agricultural waste, such as soybean husk, cassava peel, pineapple crown, corn straw, rice husk, bacaba, barley bagasse and, corncob. They were milled and sieved with a maximum granulation of 1 mm. The cultures were carried out by 132 hours 30 °C and 180 rpm. Among the agroindustrial residues, corn straw was the one that stood out with a greater enzymatic activity of 12.6 U/mL. In the second step, it was used Plackett-Burman design to screen the nutrients sources important to xylanase production. Thus, independent variables significant were urea and MgSO4. These variables selected by Plackett-Burman were then used in a Central Composite Rotational Design present activity of 26.6 U/mL and the predicted was 34.5 U/mL. So, the xylanase production by F. oxysporum can be optimize using corn straw, a low-cost waste found in large quantities.

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Background. Omega fatty acids are a family of polyunsaturated fats associated with several health benefits. Lipases are enzymes with potential application in several food processes such as flavor and aroma, surfactants and formulations for the dairy and bakery industries. In this study, single cell oil and lipase production by Candida viswanathii CCR8137 were evaluated simultaneously from renewable carbon sources under nitrogen limitation. Materials and methods. Enzyme and single cell oil were obtained in submerged cultivations supplemented with triolein, tributyrin, corn oil, sunflower oil, canola oil and olive oil. The effects of glucose on lipid accumulation, fatty acid profile, enzyme production and cell morphology were also evaluated. Results. The highest lipid accumulation (44.5%, w/w) was obtained from triolein, whereas olive oil was the best inducer of lipase synthesis (26.8 U/mL). Nitrogen limiting cultivations were a key parameter for an organic source which showed higher lipid accumulation and enzyme production than the tested inorganic nitrogen source. Glucose was a poor inducer of lipase synthesis, though increased values of lipid accumulation were observed from this carbon source with a maximum of 63.1% (w/w). The fatty acid profile of lipids produced by C. viswanathii CCR8137 showed a high content of omega-9 fatty acid (C18:1 n-9). The addition of glucose to the culture media resulted in the synthesis of essential fatty acids: vaccenic, linolenic and eicosadienoic acids. Conclusion. Therefore, C. viswanathii CCR8137 strain can be considered as an oleaginous yeast able to accumulate high concentrations of intracellular lipids, which are potential additives for food industry applications as well as being able to simultaneously synthesize high yields of lipase.