Characterization and catalytic activity of free and immobilized lipase from Aspergillus niger: a comparative study

Abstract

Lipase de Aspergillus niger foi imobilizada por deposição utilizando Celite e as atividades de hidrólise e esterificação, a estabilidade e a enantioseletividade das formas livre e imobilizada foram comparadas. Ambas as preparações mostraram propriedades bioquímicas similares, com atividade máxima em pH 6,0 e temperatura de 30-40 o C. Não foram observadas diferenças na atividade hidrolítica em função do pH para as duas formas da enzima. Os efeitos mais importantes observados após a imobilização foram a estabilidade térmica e a melhoria da atividade de esterificação na reação do (R,S)-ibuprofeno com 1-propanol em presença do isooctano. Além disso, a lipase na forma imobilizada manteve, pelo menos, 73% de sua atividade de esterificação após 5 dias de armazenamento a 40 o C e pôde ser reciclada e reutilizada por pelo menos 6 vezes.Aspergillus niger lipase was immobilized by deposition on Celite and the hydrolytic and esterification activities, stability and enantioselectivity of both free and immobilized enzyme were compared. Both the free and immobilized preparations showed similar biochemical properties, with maximum activity at pH 6.0 and a temperature of 30-40 o C. The most important effects observed when the lipase was immobilized were thermal stability and an improved esterification activity during the reaction of (R,S)-ibuprofen with 1-propanol in isooctane. Moreover, immobilized Aspergillus niger lipase maintained an esterification activity of at least 73% after 5 days of storage at 40 o C and can be recycled and reused at least 6 times.

Enantioselective synthesis of (S)‐naproxen using immobilized lipase on chitosan beads

“…These results are consistent with other research; according to the literature, [36][37][38][39][40] immobilization may reduce enzyme activity and enantioselectivity by the presence of a diffusion limitation. The enantioselectivity and conversion of Candida rugosa lipase were obtained at 191 and 0.475, respectively, which are higher than the enantioselectivity and conversion of an equal amount of immobilized enzyme.…”

Non‐selective hydrolysis of tuna fish oil for producing free fatty acids containing docosahexaenoic acid

“…Maximum hydrolysis of 13.9% equivalent to activity of 75.4 µmol FFAs formed/mL was obtained for immobilised CAL‐B at 35°C and variations in the percentage hydrolysis are less up to 50°C temperature as shown in Figure . These results also indicate that the immobilised lipases are less vulnerable at higher temperatures (between 40 and 50°C), but provides maximum activity in the moderate temperature range because moderate temperatures (between 25 and 40°C) are more suitable for the lipase recycling …”

Biodiesel production using magnetic whole-cell biocatalysts by immobilization of Pseudomonas mendocina on Fe3O4-chitosan microspheres

“…Highest enzyme activity of 2810 U/g was achieved at 8 h. This result confirms that lipases produced by MWCBs are secreted outside the cells. In the previous studies, enzyme activities of 560 U/g from Aspergillus niger [23], 1233 U/g from Thermomyces lanuginosus [24] and 1785 U/g from recombinant Pichia pastoris [25] were obtained, respectively, which are all lower than that of MWCBs. To decrease the deactivation of MWCBs, stepwise addition of methanol was used for transesterification of soybean oils [28].…”