DataPDF Available

EMPLEO DE FRACCIONES CELULARES DE LA LEVADURA Saccharomyces cerevisiae COMO ADITIVO ALIMENTARIO PARA Artemia franciscana

Authors:
Data

EMPLEO DE FRACCIONES CELULARES DE LA LEVADURA Saccharomyces cerevisiae COMO ADITIVO ALIMENTARIO PARA Artemia franciscana

Abstract

This study evaluates the disrupted Saccharomyces cerevisiae yeast (LD) and three of its fractions (membrane-wall complex (FP), yeast-protein concentrate (FN) and cytoplasm (FC)) as a food additive using Artemia franciscana as experimentation model. The effect of these additives on growth, dry biomass, survival and development was determined in two experiments (nauplii and juvenile). Different additive concentrations were applied (6, 10 mg/L) using the basal diet with Nannochloropsis oculata algae. Nauplii feeding with LD obtained the largest corporal dimensions (0.70 mm) and dry biomass (310.5 mg/L) with significant differences (p<0.05) about control (maintained only with the same algae concentration). In juveniles, the largest lengths (2.53 mm and 2.49 mm), the best survivals (75.8% and 72.5 %) and the greatest development (24.4 % y 20% in IV stage) were obtained adding LD and FP (10 mg/L) respectively. The best general results were obtained with LD inasmuch as this additive preserves completely the cellular elements. This suggests the significance of the synergic or cooperative effects among cellular components.
A preview of the PDF is not available
ResearchGate has not been able to resolve any citations for this publication.
Article
Although fish meal has historically been used as the primary source of protein in fish feeds, brewer's dried yeast (BDY) is presently being investigated as a primary replacement for fish meal. As little is known about the ability of fish to utilize BDY, studies were conducted to study bioavailability of intact BDY as well as several fractions derived from the disrupted yeast to rainbow trout.Dried BDY was fed to rainbow trout and digestibility and energy values were determined. When the yeast cells were fully disrupted, the absorption of nitrogen increased by more than 20% and the metabolizable energy of the yeast by more than 10%. Energy and nitrogen digestibility were further increased after the removal of all wall material and separation of nitrogen into amino acid and nucleic acid fractions. Disruption of the cell wall significantly increased the nutritional value of BDY for salmonid fishes. The findings suggest that further research be conducted on the use and economy of BDY as a primary nitrogen source in fish feeds.
Article
A process for the preparation of yeast-derived food additives was developed. The four products obtained, yeast protein concentrate (YPC), cell-wall protein (CWP), semi-pure glucomannan (SPG) and yeast extract, compared well with similar products, present in the current market, with respect to functional properties. YPC and CWP exhibited improved water-holding and oil-binding properties over those of soy-protein isolate (SPI). The emulsifying capacity was very close to that observed in commercial samples. A one-step alkaline extraction enhanced the functional properties of primary yeast glycan to match traditional food hydrocolloid sources. SPG showed oil-binding properties significantly greater than commercial glucomannan.
Article
In this study baker's yeast was evaluated as a substitute for live Dunuliella tertiolecta algae in the culture of the brine shrimp Artemia. Consumption of fresh baker's yeast resulted in poor growth and survival of brine shrimp. However, the nutritional value of the yeast sigaificantly improved after complete removal of the yeast cell wall by enzymatic treatment. Baker's yeast was also made digestible for Artemia by simple chemical treatment which did not reduce rigidity of the yeast cell. The external mannoprotein layer of the yeast cell wall is probably the major barrier to digestion by Artemia. Chemically treated baker's yeast offers promising possibilities as a substitute for algal feeds in aquaculture.
Article
1. A wide range of species that are cultivated in commercial mariculture are planktonic during at least part of their life cycle; for example, the larval stages of shellfish (shrimp and molluscs) and the live feeds (rotifers, brine shrimp, copepods) used in the larviculture of marine fish and shellfish. Over the last decades various techniques have been developed to deliver nutrients to these zooplanktonic organisms either through artificial diets or by manipulating the composition of the live prey fed to the carnivorous stages. This paper reviews the methodology that has allowed aquaculturists to gain knowledge of nutritional requirements and may offer interesting opportunities for ecologists to verify the importance of key nutrients in the natural food chain of marine as well as freshwater ecosystems. 2. Live micro-algae can be replaced partially or completely in the diet of filter-feeders such as rotifers, Artemia, shrimp larvae and bivalves, by various types of preserved algae, micro-encapsulated diets and yeast-based diets, whereas lipid emulsions and liposomes may be utilized to supplement specific lipid-and water-soluble nutrients, respectively. Microbound and micro-encapsulated diets have been designed to supplement live feed in the culture of micro-predators such as fish and shrimp larvae. 3. Live prey organisms, in particular rotifers and Artemia, can be ‘bio-encapsulated’ with a variety of enrichment diets to manipulate their content in certain nutrients, including ω3 highly unsaturated fatty acids (FA) and the vitamins C, A and E. Nevertheless, the enrichment techniques are not applicable for all nutrients and prey organisms. Phospholipid composition is difficult to manipulate through the diet of live feed and the enrichment of the essential FA docosahexaenoic acid (DHA) is hampered in most Artemia species due to the catabolism of this FA following enrichment.
Article
A 56-day feeding trial was conducted with juvenile tilapia (Oreochromis mossambicus), to evaluate an industrial single cell protein (Eurolysine Fodder Protein, E.F.P.) as an alternative component to fishmeal in complete diets. A control diet without E.F.P. served as a reference from which inclusion levels of 5, 10, 15 and 20% E.F.P. were investigated by the replacement of fishmeal. All diets were formulated to be isonitrogenous and isocalorific in terms of crude protein and digestible energy. On the basis of these feeding trials, Eurolysine Fodder Protein was found to successfully replace up to 40% of the fishmeal in the practical diet. However, fish fed 15 and 20% E.F.P. displayed a significant reduction in growth rate. At these levels, poor food conversion ratio, reduced net protein utilization and feed intake were attributed to an amino acid imbalance, the absence of attractants or possible deleterious effects of high nucleic acid levels.
Article
Formaldehyde was used to disinfect Artemia cysts and nauplii, while introducing two probiotics in the enrichment process: Bactocell (Pediococcus acidilactici) and Levucell (Saccharomyces cerevisiae). The disinfectant was selected due to its potential compatibility with probiotics, since it was more effective against Gram-negative bacteria than against lactic acid bacteria and yeast. However, the presence of formaldehyde reduced the intake of P. acidilactici in Artemia. Consequently, the disinfection was stopped before Bactocell supplementation to the nauplii fed to pollack (Pollachius pollachius) larvae. The mean weight of pollack was higher with this probiotic treatment. Growth was even better with the combination of Levucell and Bactocell, but the yeast should be introduced circumspectly. A high bacterial load was found in the nauplii enriched with Levucell, but not treated with formaldehyde. In the absence of Bactocell, the discontinuation of disinfecting Artemia after Levucell enrichment caused poor growth of pollack.