Oleaginous yeast as a component in fish feed

Johanna Blomqvist,Mats Sandgren,Nils Mikkelsen,Jana Pickova,Volkmar Passoth,Jule Brandenburg,Sabine Sampels,Sarvenaz Khalili Tilami

doi:10.1038/s41598-018-34232-x

Abstract

This study investigates the replacement of vegetable oil (VO) in aquaculture feed for Arctic char (Salvelinus alpinus) with oil produced by the oleaginous yeast Lipomyces starkeyi grown in lignocellulose (wheat straw) hydrolysate. VO is extensively used to partially replace fish oil in aquaculture feed, which can be seen as non-sustainable. VO itself is becoming a limited resource. Plant oils are used in many different applications, including food, feed and biodiesel. Its replacement in non-food applications is desirable. For this purpose, yeast cells containing 43% lipids per g dry weight were mechanically disrupted and incorporated into the fish feed. There were no significant differences in this pilot study, regarding weight and length gain, feed conversion ratio, specific growth rate, condition factor and hepatosomatic index between the control and the yeast oil fed group. Fatty and amino acid composition of diet from both groups was comparable. Our results in fish demonstrate that it is possible to replace VO by yeast oil produced from lignocellulose, which may broaden the range of raw materials for food production and add value to residual products of agriculture and forestry.

Highlights

Fish is one of the most traded food commodities and has great potential to contribute to food security for a growing population[1]
We have recently demonstrated that the oleaginous yeast Lipomyces starkeyi can efficiently synthesise lipids from the hemicellulose fraction of birch wood and the cellulose fraction of wheat straw[19,20], and other studies have used lignocellulose hydrolysate as a substrate for oil production with this yeast[21,22,23,24]
To replace vegetable oil (VO) in the feed for Arctic char (Salvelinus alpinus) with single cell oils derived from L. starkeyi grown on lignocellulose hydrolysate from wheat straw, i.e. a non-edible, residual material

Summary

Introduction

Fish is one of the most traded food commodities and has great potential to contribute to food security for a growing population[1]. Aquaculture is a rapidly growing industry and is an important source of animal-based foods. This growth generates an increased demand for feed for farmed fish. A sustainable further expansion of the aquaculture industry can only happen when alternative resources/replacements for FO can be found Those alternatives can be both vegetable oil (VO) and terrestrial animal oil[3,4,5,6]. The lipid composition of L. starkeyi was shown to be similar to that of saturated fatty acids (SFA) rich VO, for example olive oil or palm oil[19,20,25] In this pilot study, the aim was to test whether it is possible www.nature.com/scientificreports/. To replace VO in the feed for Arctic char (Salvelinus alpinus) with single cell oils derived from L. starkeyi grown on lignocellulose hydrolysate from wheat straw, i.e. a non-edible, residual material

Methods

Results

Conclusion