Enhanced polyunsaturated fatty acids production in Mortierella alpina by SSF and the enrichment in chicken breasts

A strategy of co-fermentation of distillers dried grains with solubles (DDGS) and lignocellulosic feedstocks as swine feed

To meet the sustainable development of the swine feed industry, it is essential to find alternative feed resources and develop new feed processing technologies. Distillers dried grains with solubles (DDGS) is a by-product from the ethanol industry consisting of adequate nutrients for swine and is an excellent choice for the swine farming industry. Here, a strategy of co-fermentation of DDGS and lignocellulosic feedstocks for production of swine feed was discussed. The potential of the DDGS and lignocellulosic feedstocks as feedstock for fermented pig feed and the complementary relationship between them were described. In order to facilitate the swine feed research in co-fermentation of DDGS and lignocellulosic feedstocks, the relevant studies on strain selection, fermentation conditions, targeted metabolism, product nutrition, as well as the growth and health of swine were collected and critically reviewed. This review proposed an approach for the production of easily digestible and highly nutritious swine feed via co-fermentation of DDGS and lignocellulosic feedstocks, which could provide a guide for cleaner swine farming, relieve stress on the increasing demand of high-value swine feed, and finally support the ever-increasing demand of the pork market.

Microbial lipids from organic wastes: Outlook and challenges

Microbial lipids have recently drawn a lot of attention as renewable sources for biochemicals production. Strong research efforts have been addressed to efficiently use organic wastes as carbon source for microbial lipids, which would definitively increase the profitability of the production process and boost a bio-based economy. This review compiles interesting traits of oleaginous microorganisms and highlights current trends on microbial- and process-oriented approaches to maximize microbial oil production from inexpensive substrates like lignocellulosic sugars, volatile fatty acids and glycerol. Furthermore, downstream processes such as cell harvesting or lipid extraction, that are decisive for the cost-effectiveness of the process, are discussed. To underpin microbial oils within the so demanded circular economy, associated challenges, recent advances and possible industrial applications that are also identified in this review.

Polyunsaturated fatty acids production by solid-state fermentation on polyurethane foam by Mortierella alpina

Polyunsaturated fatty acids (PUFAs) are essential in healthy diets and their production is extremely important. Natural sources of PUFAs includes animal and aquatic products such as marine fish oil, however there are several limitations such as the decrease of fish stocks throughout the world. Thus, microbial oils are a preferable source of PUFAs. Herein, it was studied the production of PUFAs by Mortierella alpina under solid-state fermentation (SSF) using polyurethane foam as inert substrate and synthetic medium or lignocellulosic hydrolysate as source of C, N, and other nutrients. Several parameters of fermentation conditions were evaluated as carbon source, inductors addition, ratio C/N and temperature. The highest amount of total PUFAs per mass of solid (535.41 ± 24.12 mg/g), linoleic acid (129.66 ± 5.84 mg/g), and α-linoleic acid (401.93 ± 18.10 mg/g) were produced when the culture medium contained 20 g/L glucose, 10% (w/v) linseed oil, the C/N ratio was adjusted to 25 and the incubation temperature was 25°C for 3 days decreasing to 16°C on the remaining 4 days of fermentation. In addition, a hemicellulosic hydrolysate can be used as low-cost substrate to produce PUFAs, although the production was lower than the achieved with synthetic medium. SSF showed an interesting technology for microbial PUFAs production.

Effect of supplementation with solid-state fermented feed in the diet of laying hens on egg qualitative variables

   The aim of this experiment was to evaluate the effect of the supplementation of laying hens diet with solid-state fermented feed on egg qualitative variables. The diet of laying hens was supplemented with 10% and 15% of solid-state feed fermented by the low filamentous fungal strain Mortierella alpina CCF 2861. For the trial, 30 Lohmann Brown classic layers, aged 17 weeks, were selected and individually weighed and divided into three groups (control and two experimental groups). The control group of laying hens was fed with basic feed mixture and the experimental groups received the same diet as a control group, but enriched with supplementation of solid-state fermented feed. The first experimental group was fed a diet supplemented with 10% of fermented feed and the second experimental group with 15% supplementation. The following egg qualitative variables were observed: the egg weight, Haugh units, quality grade, air cell depth, percentage of the shell, yolk and albumen, eggshell breaking force, pH of egg yolk and albumen, egg yolk colour, and antioxidant activity with the extent of lipid oxidation in egg yolk samples. The pH of yolk and albumen did not show differences between all examined eggs originating from the experimental groups of laying hens (p >0.05). The eggs from both experimental groups had a significantly higher eggshell hardness than eggs produced by the hens of the control group (p <0.05). Antioxidant activity of egg yolk of experimental samples increased with the supplementation of fermented feed in the diet of laying hens (p <0.05). The specific lightness of egg yolk colour increased significantly in the experimental group with 15% of supplementation (p <0.01). The obtained results showed that feeding laying hens with fermented feed positively affected the quality of produced eggs. This was the first study and further investigation before using the fermented feed in commercial laying hen farms is necessary.