Three Zygomycetes, Mortierella isabellina, Thamnidium elegans and Mucor sp., were tested for their ability of producing biomass and lipid‐containing γ‐linolenic acid (GLA) during their cultivation on cheese whey. M. isabellina consumed all of the available lactose and a significant amount of the available protein. On the contrary, the two other fungi seemed incapable of consuming lactose after protein exhaustion. In the second series of experiments, for M. isabellina a supplementary quantity of lactose was added into the medium in order to increase the C/N ratio and hence to increase the production of fat. In the case of T. elegans and Mucor sp., a supplementary quantity of ammonium sulfate was added in order to favor the consumption of lactose and the production of biomass. Indeed, enhancement of lipid production was observed for M. isabellina and biomass production for T. elegans and Mucor sp.. Fatty acid analysis of the microbial lipid showed a composition that presented non‐negligible changes in relation with the age of the culture and the C/N molar ratio of the medium. Further analysis of the fat showed that the quantity of neutral lipids was the more abundant. The fatty acid composition of neutral lipids resembled to that of total lipids. Phospholipids were the more unsaturated fraction for Mucor sp. and M. isabellina. GLA was synthesized in all trials but its concentration presented differences related with the utilized strains and the fermentation time. Growth of M. isabellina on lactose‐supplemented whey resulted in a maximum GLA production of 301 mg/L.

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-Individual milk samples taken from goats of the Skopelos breed of Greece were analyzed by RP-HPLC using as standards the casein fraction of milks of known genotypes. Milk samples with particular characteristics with respect to the casein fraction were further analyzed by IEF and RP-HPLC/ESI-MS. The mean total protein content (36.7 ± 2.6 g·L -1 ) and the mean casein content (29.7 ± 2.3 g·L -1 ) were high. The same was true for the α s1 -cn fraction, which was 21.8% of the total cn fraction, whereas the β-cn percentage of total cn was 43.8%. The respective values for α s2 -cn and κ-cn were 13.7% and 13.8%. These quantitative characteristics were consistent with the predominance of the strong α s1 -cn variants B3, B4 and As/B1. In all samples analyzed by RP-HPLC/ ESI-MS the deleted form differing from the respective complete form by Gln78 was found at different levels of phosphorylation, with the exception of variants F and D/G. The most frequent α s2 -cn variant was by far variant A followed by variants C and F, whereas compositional data implied the existence of a null allele. The detected β-cn forms were variants A and C in similar frequencies. Variant D (formerly B) of κ-cn predominated and the rare variant G was found. Different phosphorylation types of each casein variant and the characteristics of whey proteins were also determined.goat milk protein / casein genotype / phosphorylation / protein quantification / polymorphism Résumé -Polymorphisme des protéines du lait de chèvre de la race Skopelos. Des laits individuels de chèvres de Skopelos (Grèce) ont été analysés par RP-HPLC et les profils protéiques ont été comparés avec ceux issus de lait de chèvres de génotypes connus au locus α s1 . Les échantillons qui présentaient des caractéristiques particulières de leur fraction caséique ont été analysés par IEF et RP-HPLC/ESI-MS. Les teneurs moyennes en protéines totales (36,7 ± 2,6 g·L -1 ), et en caséines (29,7 ± 2,3 g·L -1 ), étaient plus élevées que dans les laits des races hautement sélectionnées. Le pourcentage en α s1 -cn représentait 21,8 % des caséines totales, tandis que celui de la β-cn atteignait 43,8 %. Les pourcentages en α s2 -cn et κ-cn étaient respectivement 13,7 % et 13,8 %. Ces caracté-ristiques quantitatives étaient corrélées avec la prédominance des variants forts B3, B4 et As/B1 de la α s1 -cn. Dans tous les échantillons analysés par RP-HPLC/ESI-MS, la forme déplétée en Gln78 de la α s1 -cn présentait plusieurs niveaux de phosphorylation, à l'exception des variants F et D/G. Le variant le plus abondant de la α s2 -cn était le variant A suivi par les variants C et F. Les variants A et C de la β-cn ont été trouvés en fréquences similaires. Le variant D (antérieurement dénommé B) de la κ-cn était prédominant bien que le variant rare G était aussi trouvé. Plusieurs niveaux de phosphorylation de chacun de ces variants ont été aussi mis en évidence, ainsi que les principales caractéristiques des protéines du sérum.polymorphisme / variant proteique / lait de chèvre / caséine / génotype /...