In the last decade, has increased the demand for enzymes of microbial origin to diverse industrial processes. Therefore, the aim of these research was the partial biochemical characterization of an extracellular lipase of Marinobacter sp isolated from the Salinas de Pilluana (San Martin), using the response surface methodology. Were analyzed the effect of factors such as: pH (4,0 – 9,0), temperature (32,5 – 45,0 °C), time (0,0 – 40,0 min) and the concentrations of NaCl (0,0 – 10,0%) and CaCl2 (0,0 – 1,0%), on the specific activity through the Box-Behnken experimental statistical design employed in three levels. In addition, were determined the catalytic constants (Km and Vmax) and the thermal stability of the enzyme. The optimal reaction parameters to lipase from Marinobacter sp. were pH 7,0; 37 °C and 30 min, using as substrate p-nitrophenyl palmitate. The Vmax and Km of the...

In the last decade, has increased the demand for enzymes of microbial origin to diverse industrial processes. Therefore, the aim of these research was the partial biochemical characterization of an extracellular lipase of Marinobacter sp isolated from the Salinas de Pilluana (San Martin), using the response surface methodology. Were analyzed the effect of factors such as: pH (4,0 – 9,0), temperature (32,5 – 45,0 °C), time (0,0 – 40,0 min) and the concentrations of NaCl (0,0 – 10,0%) and CaCl2 (0,0 – 1,0%), on the specific activity through the Box-Behnken experimental statistical design employed in three levels. In addition, were determined the catalytic constants (Km and Vmax) and the thermal stability of the enzyme. The optimal reaction parameters to lipase from Marinobacter sp. were pH 7,0; 37 °C and 30 min, using as substrate p-nitrophenyl palmitate. The Vmax and Km of the...

The accelerated loss of glacial cover in the Cordillera Blanca in Áncash, Peru, exposes the underlying rocks with high concentrations of sulfides from the Chicama Formation to oxidation and leaching processes, generating acid rock drainage (ARD) in glacial and periglacial areas. These are transported by surface runoff, contaminating the surface water with high concentrations of metals and sulfates, as well as increasing the acidity, which poses a risk to human health and the ecosystem. Therefore, the risk indices for human health due to metal contamination were evaluated at 19 surface water sampling points distributed in the Río Negro sub-basin. Hydrochemical analyses revealed average metal concentrations in the following order: Fe (28.597 mg/L), Al (3.832 mg/L), Mn (1.085 mg/L), Zn (0.234 mg/L), Ni (0.085 mg/L), Co (0.053 mg/L), Li (0.036 mg/L), Cu (0.005 mg/L), and Pb (0.002 mg/L). T...