title: [Value of alkane-produced protein and three animal meals for growth and body nitrogen of meal worms (Tenebrio molitor L.)].
abstract: Different types of chemical and biological procedures for screening protein quality of many foods are available. It is recognized however that such assays cannot be part of a routine screening technic. For good technologists and plant breeders in search of novelties, the main problems arise from the small size of samples available and the need to evaluate a large number of materials in a short period of time. The development of more accurate, economical and/or faster bioassay methods would be useful for solving some of the general and applied nutrition problems. The possibility of using larvae of the yellow mealworm (Tenebrio molitor L.) as a bioassay test organism for nutritional evaluation of proteins has been suggested (8) and previous investigations (9, 10, 11, 12,13, etc.) indicated that these larvae can be used in such studies because of a short, rapid growth period and a sensitivity to  slight changes in protein quality and quantity. The present investigation was designed to asses the nutritional quality of artificial diets containing various levels of BP-protein (pure n-alkanes grown yeast or yeast G) when fed to larvae of T. molitor. The results were compared with those of Difco vitamin-free casein, fish and meat meals studied in the same manner. The chemical compositions of these proteins sources was also reported. Defatted meals of the samples were used to prepare diets containing from 0,6 to 20 p. 100 of dietary protein. The basic protein free diet used contained: dextrose: 97 p. 100, McCollum's salt mixture: 2 p. 100, cholesterol: 1 p. 100 and  a solution of B-vitamins and zinc chloride: 0,1 ml/g. The dextrose portion of the diets is adjusted as the protein concentration fluctuates. Larvae of T. molitor, Gembloux strain, race F, ranging in weight from 9,60 to 12,00 mg were selected from stock cultures, rearing in the ground wheat-Brever's yeast medium. They were starved for 48 hr. and were weighed again before being placed on the test diets for 4 weeks. Groups of thirty larvae having an average initial weight of approximately 10 mg were reared individually in vials at 27 degrees C and 70 p. 100 relative humidity with 1,5 g of diet each. At the end of the experimental period,the larvae were weighed to the nearest 0,1 mg and the gains in fresh weight were recorded. Then, all the larvae from the same diet, previously killed with chloroform were used from nitrogen determinations. Data on gains in weight and body nitrogen of larvae were analyzed, using analysis of variance and NEWMAN and KEUL's multiple range test. The results suggest that the protein levels allowing maximuum growth and body nitrogen vary from 9 to 12 p. 100 and these levels were suitable for the comparisons. Based on the criterion of larval weight, the nutritional quality of the protein sources was : BP-protein greater than casein = fish meal greater than meat meal (P less than 0,01)...
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001681:Biological Assay; D001835:Body Weight; D002364:Caseins; D004044:Dietary Proteins / Q000008:administration & dosage / Q000032:analysis; D005394:Fish Flour; D007814:Larva / Q000378:metabolism; D008460:Meat; D008903:Minerals / Q000032:analysis; D009584:Nitrogen / Q000378:metabolism*; D010578:Petroleum; D013712:Tenebrio / Q000378:metabolism*; D015003:Yeasts / Q000378:metabolism
chemical_list: D000596:Amino Acids; D002364:Caseins; D004044:Dietary Proteins; D008903:Minerals; D010578:Petroleum; D009584:Nitrogen
vernacular_title: Valeur des protéines d'alcanes et de trois farines animales pour la croissance et l'azote corporel du ver de farine (Tenebrio molitor L.)