Extracellular methionine amino peptidase (MAP) production by Streptomyces gedanensis in solid-state fermentation

A bioprocess was developed for extracellular MAP production from Streptomyces gedanensis by solid-state fermentation. Response surface methodology of Box Behken Design was performed to evaluate the interaction effects of most significant variables {inoculum size, (NH4)2SO4 concentration, MgSO4.7H2O and tryptone) on MAP production after the single parameter optimization and it resulted a maximum MAP production of 55.26 IU/g PUF after 120 h of fermentation. The concentrated crude MAP displayed a pH and temperature optimum of 8.5 and 50°C. By analyzing the thermal stability, the MAP was found to be stable in a temperature range of 50 to 55°C but lost about 50% of its activity at 65°C after 30 min. This is a first report of this kind of study for MAP.

Arginine specific aminopeptidase from Lactobacillus brevis

The proteolytic system of lactic acid bacteria contribute to the development of flavor during the ripening of cheese through the generation of short peptides and free amino acids, which directly or indirectly act as flavor precursors. Newly isolated lactic acid bacteria (LAB) as well as those procured from culture collection centers were screened for the production of various substrate specific aminopeptidases. Among all the strains screened, L. brevis (NRRL B-1836) was found to produce quantifiable amount of intracellular arginine specific aminopeptidase (EC 3.4.11.6). The productivity of arginine aminopeptidase in 5 L fermentor was 36 IU/L/h. The Luedeking and Piret model was tested for intracellular production of aminopeptidase and the data seemed to fit well, as the correlation coefficient was 0.9964 for MRS. The αAP and βAP was 0.4865 and 0.0046, respectively in MRS medium indicating that the yield was predominantly depended on growth. The culture produced lactic acid and also tolerated pH 2.0-3.0 and 0.3-0.5 percent bile salts, the most important probiotic features.

Arginine specific aminopeptidase from Lactobacillus brevis

The proteolytic system of lactic acid bacteria contribute to the development of flavor during the ripening of cheese through the generation of short peptides and free amino acids, which directly or indirectly act as flavor precursors. Newly isolated lactic acid bacteria (LAB) as well as those procured from culture collection centers were screened for the production of various substrate specific aminopeptidases. Among all the strains screened, L. brevis (NRRL B-1836) was found to produce quantifiable amount of intracellular arginine specific aminopeptidase (EC 3.4.11.6). The productivity of arginine aminopeptidase in 5 L fermentor was 36 IU/L/h. The Luedeking and Piret model was tested for intracellular production of aminopeptidase and the data seemed to fit well, as the correlation coefficient was 0.9964 for MRS. The αAP and βAP was 0.4865 and 0.0046, respectively in MRS medium indicating that the yield was predominantly depended on growth. The culture produced lactic acid and also tolerated pH 2.0-3.0 and 0.3-0.5 percent bile salts, the most important probiotic features.

Alpha amylase from a fungal culture grown on oil cakes and its properties

Fermentação no Estado Sólido foi empregada na produção de alfa-amilase usando Aspergillus niger. Diferentes tipos de torta foram utilizadas, como torta de óleo de coco (COC), torta de de óleo de amendoim (GOC) torta de óleo de sesamo (SOC), torta de palma (PKC) e torta de óleo de oliva (OOC) foram selecionadas para serem usadas como substratos para produção de enzima e comparadas com o farelo de trigo (WB), GOC foi escolhido por ser o que produziu maiores concentrações de enzima. A combinação WB e GOC (1:1) resultou em maiores títulos da enzima quando em comparação com os substratos individuais. A máxima concentração de enzima (9196 U/ gms) foi obtida quando a FES foi conduzida utilizando WB + GOC, com umidade de 64% e suplementada com lactose e nitrato de amônia (1% cada) a 300C por 72 horas utilizando 2 mL de uma suspensão de esporo (6x107sporos/ml). A purificação parcial da enzima usando frações de sulfato de amônio resultou num aumento de 2-4 vezes o aumento da atividade. A enzima apresentou um peso molecular de 68 Kda pelo SDS_PAGE. Exceto Mn, todos os outros íons metálicos como Ca, K, Na, Mg são inibitórios na produção da enzima.