The aims of this work were to establish improved conditions for lipase production by Candida viswanathii using agroindustrial wastes in solid-state cultivation and to purify and evaluate the application of this enzyme for poultry fat hydrolysis. Mixed wheat bran plus spent barley grain (1 : 1, w/w) supplemented with 25.0% (w/w) olive oil increased the lipase production to 322.4%, compared to the initial conditions. When olive oil was replaced by poultry fat, the highest lipase production found at 40% (w/w) was 31.43 U/gds. By selecting, yeast extract supplementation (3.5%, w/w), cultivation temperature (30°C), and substrate moisture (40%, w/v), lipase production reached 157.33 U/gds. Lipase was purified by hydrophobic interaction chromatography, presenting a molecular weight of 18.5 kDa as determined by SDS-PAGE. The crude and purified enzyme showed optimum activity at pH 5.0 and 50°C and at pH 5.5 and 45°C, respectively. The estimated half-life at 50°C was of 23.5 h for crude lipase and 6.7 h at 40°C for purified lipase. Lipase presented high activity and stability in many organic solvents. Poultry fat hydrolysis was maximum at pH 4.0, reaching initial hydrolysis rate of 33.17 mmol/L/min. Thus, C. viswanathii lipase can be successfully produced by an economic and sustainable process and advantageously applied for poultry fat hydrolysis without an additional acidification step to recover the released fatty acids.
Quitina e quitosana são polissacarídeos encontrados na natureza, insolúveis em água e solventes orgânicos, pertencentes aos biomateriais. São encontrados em diversas fontes como algas, fungos e exoesqueleto de artrópodes. Os primeiros relatos a serem descritos a respeito de quitina foram em 1811 e sobre quitosana em 1859 e na atualidade são bastante importantes em virtude de sua ampla gama de aplicações, entre elas área de cosméticos, meio ambiente, alimentícia, farmacêutica, odontológica e médica. Os países que encabeçam o ranking dos maiores investimentos em pesquisas e produçãorelacionadas à quitina e quitosana são: Japão, seguido dos Estados Unidos, juntos são os maiores pesquisadores, produtores e consumidores destes polímeros. Características importantes destes polissacarídeos reforçam a necessidade de mais pesquisas voltadas para sua utilização, como biodegradabilidade, biocompatibilidade e baixa toxicidade. Assim, cada vez mais se deve investir em pesquisas com quitina e quitosana com o intuito de propiciar melhor qualidade de vida utilizando materiais naturais e sem agressão ao meio ambiente.
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.
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