Potential of non-Saccharomyces yeast to produce non-alcoholic beer.

Recently, non-Saccharomyces yeast have become very popular in wine and beer fermentation. Their interesting abilities introduce novel aromatic profiles to the fermented product. In this study, screening of eight non-Saccharomyces yeast (Starmerella bombicola, Lindnera saturnus, Lindnera jadinii, Zygosaccharomyces rouxii, Torulaspora delbrueckii, Pichia kluyveri, Candida pulcherrima, and Saccharomycodes ludwigii) revealed their potential in non-alcoholic beer production. Conditions for non-alcoholic beer production were optimised for all strains tested (except T. delbrueckii) with the best results obtained at temperature 10 to 15 °C for maximum of 10 days. Starmerella bombicola, an important industrial producer of biosurfactants, was used for beer production for the first time and was able to produce non-alcoholic beer even at 20°C after 10 days of fermentation. Aromatic profile of the beer fermented with S. bombicola was neutral with no negative impact on organoleptic properties of the beer. The most interesting organoleptic properties were evaluated in beers fermented with L. jadinii and L. saturnus, which produced banana-flavoured beers with low alcohol content. This work confirmed the suitability of mentioned yeast to produce non-alcoholic beers and could serve as a steppingstone for further investigation.

Lipid Peroxidation Process in Meat and Meat Products: A Comparison Study of Malondialdehyde Determination between Modified 2-Thiobarbituric Acid Spectrophotometric Method and Reverse-Phase High-Performance Liquid Chromatography.

The aim of this work was to compare the methods of malondialdehyde detection, as the main secondary product of the lipid peroxidation process, in meat and meat products. Malondialdehyde measurements were performed by two modified methods, the 2-thiobarbituric acid spectrophotometric method and the reverse-phase high-performance liquid chromatography in raw, mechanically-deboned chicken meat and in manufactured frankfurters. The malondialdehyde concentrations measured by the 2-thiobarbituric acid spectrophotometric method were found to be overestimated by more than 25% in raw meat and more than 27% in frankfurters in comparison to the results of reverse-phase high-performance liquid chromatography (p < 0.05). The achieved results showed that the presented modified reverse-phase high-performance liquid chromatography method was more applicable and more accurate for the quantification of malondialdehyde in samples of meat and meat products.

Biosynthesis of Essential Polyunsaturated Fatty Acids in Wheat Triggered by Expression of Artificial Gene.

The artificial gene D6D encoding the enzyme ∆6desaturase was designed and synthesized using the sequence of the same gene from the fungus Thamnidium elegans. The original start codon was replaced by the signal sequence derived from the wheat gene for high-molecular-weight glutenin subunit and the codon usage was completely changed for optimal expression in wheat. Synthesized artificial D6D gene was delivered into plants of the spring wheat line CY-45 and the gene itself, as well as transcribed D6D mRNA were confirmed in plants of T0 and T1 generations. The desired product of the wheat genetic modification by artificial D6D gene was the γ-linolenic acid. Its presence was confirmed in mature grains of transgenic wheat plants in the amount 0.04%-0.32% (v/v) of the total amount of fatty acids. Both newly synthesized γ-linolenic acid and stearidonic acid have been detected also in leaves, stems, roots, awns, paleas, rachillas, and immature grains of the T1 generation as well as in immature and mature grains of the T2 generation. Contents of γ-linolenic acid and stearidonic acid varied in range 0%-1.40% (v/v) and 0%-1.53% (v/v) from the total amount of fatty acids, respectively. This approach has opened the pathway of desaturation of fatty acids and production of essential polyunsaturated fatty acids in wheat.

Characterization of membrane-bound fatty acid desaturases.

Membrane-bound desaturases play key role in metabolism of polyunsaturated fatty acids. Characterization of these enzymes and their genes is the first step in basic understanding of their proper functioning in living cells as well as in tailor-made preparation of highly-specific and highly-productive strains of microorganisms interesting for applied biotechnology. It is also the crucial step in creation of transgenic agricultural crops with enhanced content of individual polyunsaturated fatty acids. Properties and applications of identified membrane-bound desaturases genes and enzymes are discussed in this review.

Animal Fat as a Substrate for Production of n-6 Fatty Acids by Fungal Solid-State Fermentation.

The method of solid-state fermentation (SSF) represents a powerful technology for the fortification of animal-based by-products. Oleaginous Zygomycetes fungi are efficient microbial cell factories used in SSF to valorize a wide range of waste and rest cereal materials. The application of this fermentation technique for utilization and biotransformation of animal-based materials represents a distinguished step in their treatment. In this study, for the first time, the strain Umbelopsis isabellina CCF2412 was used for the bioconversion of animal fat by-products to the fermented bioproducts enriched with n-6 polyunsaturated fatty acids, mainly γ-linolenic acid (GLA). Bioconversion of both cereals and the animal fat by-product resulted in the production of fermented bioproducts enriched with not just GLA (maximal yield was 6.4 mg GLA/g of fermented bioproduct), but also with high yields of glucosamine. Moreover, the fermentation on the cornmeal matrix led to obtaining bioproduct enriched with ß-carotene. An increased amount of ß-carotene content improved the antioxidant stability of obtained fermented bioproducts. Furthermore, the application of Fourier-transform infrared spectroscopy for rapid analysis and characterization of the biochemical profile of obtained SSF bioproducts was also studied.

Dual production of polyunsaturated fatty acids and beta-carotene with Mucor wosnessenskii by the process of solid-state fermentation using agro-industrial waste.

Solid-state fermentation is a technique employing microorganisms grown on a solid substrate in the absence of free water. The substrates used in this process are mostly waste from the agro-industry (brans, spent malt grains, distiller grains, etc.) that improves not only the economy of the process but also has positive effect on waste management problems. Zygomycetous fungi are not only able to grow in such conditions but also enrich fermented materials with various types of bioactive compounds. Mucor sp. strains have been identified as producers of gamma-linolenic acid and beta-carotene in submerged fermentation. The aim of the present study was to identify the best microbial producer of gamma-linolenic acid and beta-carotene among four different Mucor strains and to study the requirements for the dual production of these metabolites. Mucor wosnessenskii was identified as the most suitable producer of both metabolites. After optimization of the fermentation conditions, the highest yields obtained were 10.7 g of gamma-linolenic acid/kg of fermented product and 261.5 mg of beta-carotene/kg of fermented product. This yield of beta-carotene is the highest among the results published so far.

Biotransformation of Animal Fat-By Products into ARA-Enriched Fermented Bioproducts by Solid-State Fermentation of Mortierella alpina.

Solid-state fermentation (SSF) is a powerful fermentation technology for valorizing rest materials and by-products of different origin. Oleaginous Zygomycetes fungi are often used in SSF as an effective cell factory able to valorize a wide range of hydrophilic and hydrophobic substrates and produce lipid-enriched bioproducts. In this study, for the first time, the strain Mortierella alpina was used in SSF for the bioconversion of animal fat by-products into high value fermented bioproducts enriched with arachidonic acid (ARA). Two cereals-based matrixes mixed with four different concentrations of animal fat by-product were evaluated for finding optimal conditions of a fat-based SSF. All obtained fermented bioproducts were found to be enriched with ARA. The highest substrate utilization (25.8%) was reached for cornmeal and it was almost double than for the respective wheat bran samples. Similarly, total fatty acid content in a fermented bioproduct prepared on cornmeal is almost four times higher in contrast to wheat bran-based bioproduct. Although in general the addition of an animal fat by-product caused a gradual cessation of ARA yield in the obtained fermented bioproduct, the content of ARA in fungal biomass was higher. Thus, M. alpina CCF2861 effectively transformed exogenous fatty acids from animal fat substrate to ARA. Maximum yield of 32.1 mg of ARA/g of bioproduct was reached when using cornmeal mixed with 5% (w/w) of an animal fat by-product as substrate. Furthermore, implementation of attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy in characterization of obtained SSF bioproducts was successfully tested as an alternative tool for complex analysis, compared to traditional time-consuming methods.

Effect of Solid-State Fermented Wheat Bran Supplemented with Agrimony Extract on Growth Performance, Fatty Acid Profile, and Meat Quality of Broiler Chickens.

The impact of the broiler diet modification on the following parameters was evaluated: meat quality, carcass traits, and bone and blood parameters. One hundred twenty one-day-old COBB 500 broiler chickens were assigned to three experimental groups (40 birds per group) with four replications (10 per pen) for 35 days of fattening. The control (C) was fed a basic feed mixture. The diet supplemented with 10% of fermented feed (FF10) and additionally supported by 0.2% of agrimony extract (FF10 + AE) was applied to the second and third groups, respectively. FF10 showed both a lower average daily feed intake and total feed consumption when compared to that of C (p < 0.05). Lower concentration of alkaline-phosphatase and calcium and higher total lipids and triglycerides in blood were observed in FF10 + AE. Breast and thigh meat showed a lower content of polyunsaturated fatty acid n-3 and n-6 in the FF10 + AE group (p < 0.01). The increase of gamma-linolenic acid content in breast and thigh meat samples obtained from the experimental groups was significant (p < 0.001 and p < 0.05; respectively). Lower lipid oxidation was observed in the thigh muscle of the FF10 + AE group on the first day of storage (p < 0.01). The current study indicates that FF10 + AE supplementation can be successfully applied to enhance broiler performance and meat quality.

Effect of Fungal Solid-State Fermented Product in Broiler Chicken Nutrition on Quality and Safety of Produced Breast Meat.

The aim of this work was to analyse the effect of addition of 10% (w/w) fermented bioproduct into commercial broiler feed on fatty acid profile, lipid oxidative stability, and sensory properties of chicken breast meat. The fermented bioproduct was prepared by fermentation of cornmeal by filamentous fungi Umbelopsis isabellina CCF 2412 in solid-state fermentation (SSF) process and the final bioproduct was enriched with gamma-linolenic acid and beta-carotene. In the experiment, 80 pieces of 1-day-old chickens COBB 500 were used. Half of them (control group) were fed only with commercial feed. Chickens of the experimental group were fed with commercial feed, and, from the 11th day of age until the time of slaughter (39th day), 10% of commercial feed was replaced with fermented bioproduct. Application of fermented bioproduct into commercial feed mixture positively influenced profile of fatty acids in breast meat. The amount of gamma-linolenic, alpha-linolenic, and oleic acids in fat of breast muscles was increased and n-6/n-3 ratio was significantly decreased. Profile and content of PUFAs did not change after thermal treatment of meat. Oxidative stability of fat and sensory properties of the meat during the storage (4°C, 7 days) of meat were not affected by fermented bioproduct.

Progress in the genetic engineering of cereals to produce essential polyunsaturated fatty acids.

Essential polyunsaturated fatty acids with more than two double bonds and length of carbon chain 18-22 must be taken in the diet to prevent diseases and imbalances caused by their deficiency. Terrestrial sources of polyunsaturated fatty acids are limited to only a few plant species whose large-scale cultivation is not possible and the production of their seeds and oil is ineffective. The complete biosynthetic pathway of fatty acids is known in organisms, including plants. After the first gene encoding the enzyme catalysing the initial steps of PUFA biosynthesis (ω-3 desaturase, Δ6-desaturase) were isolated, isolation of other genes encoding relevant enzymes of the PUFA pathway from different donor organisms followed. Genetic transformations of model plants by the desaturase- and elongase-encoding genes opened the way for the genetic engineering of oilseed crop species. Some of the developed transgenic plants produced PUFAs, including eicosapentaenoic and docosahexaenoic acids. Seed oils extracted from them were similar to fish oil. Tools of the synthetic biology can be applied in modifications of the PUFA pathway and also in overcoming of limitations when the gene and its expression product are absent in the pathway. Such progress in cereals (barley, wheat, maize) has been made only recently, when the first successful modifications of the ω-3 and ω-6 PUFA pathways succeeded. This review focuses on genetic modifications of the PUFA biosynthetic pathway in cereals in relation to the status reached in model plants and oilseed crops.

Biosynthesis of gamma-linolenic acid and beta-carotene by Zygomycetes fungi.

Due to increasing demand for natural sources of both polyunsaturated fatty acids (PUFAs) and beta-carotene, 28 Zygomycetes fungal soil isolates were screened for their potential to synthesize these biologically active compounds. Although all fungi produced C18 PUFAs, only nine strains also formed beta-carotene. Although Actinomucor elegans CCF 3218 was the best producer of gamma-linolenic acid (GLA) (251 mg/L), Umbelopsis isabellina CCF 2412 was found to be the most valuable fungus because of the dual production of GLA (217 mg/L) and beta-carotene (40.7 mg/L). The calculated ratio of formed PUFAs provided new insight into activities of individual fatty acid desaturases involved in biosynthetic pathways for various types of PUFAs. The maximal activity of delta-9 desaturase was accompanied by high accumulation of storage lipids in fungal cells. On the other hand, maximal activity of delta-15 desaturase was found in strains synthesizing low amounts of oleic acid due to diminished delta-9 desaturase. Activities of delta-6 desaturase showed competition for fatty acids engaged in n3, n6, and n9 biosynthetic pathways. Such knowledge about fatty acid desaturase activities provides new challenges for the regulation of biotechnological production of PUFAs by Zygomycetes fungi.