Stability of enzyme complex solid-state fermentation subjected to the processing of pelleted diet and storage time at different temperatures

Abstract

-The effects of processing of pelleted diets and their storage time on the stability of the enzyme complex SSF (solid-state fermentation) were evaluated. Two diets were formulated with the same nutritional composition, differing only in the Schizochytrium sp. levels (0 g kg -1 and 50 g kg -1 ). The samples were collected during the following processing steps: mixing, then pelleting, and then oven. To evaluate the storage time, the diet ready after drying was considered as day 1. On this day, two samples were obtained, being one kept in a room with ambient temperature of 25 °C and another stored in freezer at -18 °C. At 15, 30, 45, and 60 days, sub-samples were taken. All samples from the processing step and storage time were sent to the laboratory and the following enzyme activities were measured: α-galactosidase, endoglucanase (carboxy-methyl-cellulase), xylanase, sucrase, amylase, lipase, and trypsin. There were no significant differences between the mixture and post-oven phase, except for the activity of α-galactosidase, lipase, and sucrase. For the storage temperature of 25 °C, no effect was observed for the activities of endoglucanase, sucrase, xylanase, amylase, and trypsin between the first (after oven) and the 60th day of the trial. As for the storage temperature of -18 °C, no difference was observed, except for the activities of endoglucanase and xylanase between the first and last day. Comparing the two types of storage (25°C and -18°C), there was difference only for the activity of galactosidase and trypsin at 60 days. The enzymes of the enzyme complex SSF studied remain stable during the processing of pelleted diet at 55 °C, maintaining activity for at least 60 days when stored at temperatures up to 25 °C.

Potential of Trichoderma harzianum and Its Metabolites to Protect Wheat Seedlings against Fusarium culmorum and 2,4-D

“…The enzymes activity study was performed according to Moura et al’s method [ 46 ]. Briefly, 200 mg of fresh plant biomass (with shoots and roots separated) was ground in a mortar with freeze-drying in liquid nitrogen, then 1 mL of extraction buffer (0.05 M sodium phosphate buffer pH 7.8, 1 mM EDTA, 1%PVP) was added to the powdered tissue.…”

Biochemical and Thermodynamic Characterization of β amylase from Dioscorea alata L.

“…The enzyme was incubated in 50 mM acetate buffer pH 5 in the presence of each of the following salts: NaCl, CaCl The effect of metals on the half-life of the enzyme was determined at a final concentration of 100 mM. The half-life was determined by the relationship: (8) Where k d is the deactivation rate constant that can be derived from: (9) Where Vo is the initial enzyme activity while V is the enzyme activity at time t of incubation; and d k  can be obtained from the plot of: (10) The D-value (decimal reduction time) is the time (min) to reduce 90 % of the enzyme activity and is given by the following equation (11)…”

“…It is one of the most widely cultivated and eaten plants. About 75-84 percent of the dry weight of yam is starch [10]. This might be used to determine the expression of numerous enzymes in the crop's subcellular regions, catalysing the conversion of starch into its many derivatives.…”

Purification and Interaction of β-amylase from Dioscorea alata (Water Yam) with Epicatechin

“…It is one of the most cultivated and consumed species. Yam comprises about 75-84% dry weight starch [13] and could serve as a measure of the expression of various enzymes in subcellular locations of the crop responsible for catalyzing starch into its respective products. It could be a good source to meet the high demand for industrial starch hydrolyzing enzymes such as β-amylase.…”