Oral Administration of an Enzymatic Protein Hydrolysate from the Green Microalga Chlorella vulgaris Enhances the Nutritional Recovery of Malnourished Mice

Oral administration of an aqueous extract from the oyster mushroom Pleurotus ostreatus enhances the immunonutritional recovery of malnourished mice

Mushroom nutriceutical components have lately attracted interest for developing immunonutritional support. However, there is relatively little information pertaining to the use of mushroom preparations for modulating the metabolic and immunological disorders associated to malnutrition. This study was aimed to evaluate the effects of oral administration of an aqueous extract (CW-P) from Pleurotus ostreatus on the recovery of biochemical and immunological functions of malnourished mice. 8-week old female BALB/c mice were starved for 3days and then refed with commercial diet supplemented with or without CW-P (100mg/kg) for 8days. Regardless of the diet used during refeeding, animal body weights and serum protein concentrations did not differ between groups. Oral treatment with CW-P normalized haemoglobin levels, liver arginase and gut mucosal weight. CW-P increased total liver proteins and also DNA and protein contents in gut mucosa. Pleurotus extract provided benefits in terms of macrophages activation as well as in haemopoiesis, as judged by the recovery of bone marrow cells and leukocyte counts. Moreover, CW-P stimulated humoral immunity (T-dependent and T non-dependent antibodies responses) compared to non-supplemented mice. CW-P extract from the oyster mushroom can be used to develop specific food or nutritional supplement formulations with potential clinical applications in the immunotherapy.

Properties of microalgal enzymatic protein hydrolysates: Biochemical composition, protein distribution and FTIR characteristics

Chlorella vulgaris SAG 211-12, a green microalga, as model organism was cultivated photomixotrophically using various organic carbon and nitrogen sources at Erlenmeyer scale. The modified medium selected for the experiments was standard BG11 supplemented with 5 g l^-1 glucose and 1 g l^-1 proteose peptone (PP). To evaluate the effects of light/dark cycles, 12:12; 18:6 and 24:0 light/dark cycle conditions were examined on hourly basis. 24:0 continuous illumination condition was chosen to continue 2 l continuous stirred tank photobioreactor (CSTR) experiments under 1 vvm aeration, 120 rpm mixing time, 23 ± 2 °C, and 70 μE m^-2 s^-1 illumination conditions. The results showed significant effect of the culture conditions on the cellular composition. To enhance digestibility of the intact cell; dry biomass was digested with pancreatin enzyme solution and in vitro protein digestibility (IVPD) of crude biomass (UTS), cell debris (CVA) and protein hydrolysates (CVH) was measured. IVPD values of UTS, CVA and CVH were found to be 33-41%, 46-58%, 67-89%; respectively with no significant changes regarding culture conditions (p > 0,05). Results also showed the positive effect of the enzyme treatment for digestion which is a key advantage for nutritional characteristic of the algal biomass.

Optimal extraction and hydrolysis of Chlorella pyrenoidosa proteins

In this study, for the first time, the applications of two new methods, ionic liquid and low-temperature high-pressure cell breakage methods, to the extraction of whole proteins in Chlorella pyrenoidosa cells were explored. Meanwhile, the comparison with three traditional methods was also made. The results indicated that the extraction rate for ionic liquid is only at moderate level, but the new low-temperature high-pressure cell breakage method can obviously increase the protein extraction rate up to 2- to 15-fold. Subsequently, the hydrolysis of the extracted proteins was conducted with three enzymes (papain, trypsin and alcalase). The data presented that the degree of hydrolysis for each enzyme under the optimal conditions is in the order of: alcalase (18.31%)>papain (14.33%)>trypsin (8.47%), demonstrating the potential of C. pyrenoidosa protein hydrolysates obtained here in nutritional supplement and medical foods.