Cultured meat from muscle stem cells: A review of challenges and prospects

Growing muscle tissue in culture from animal stem cells to produce meat theoretically eliminates the need to sacrifice animals. So-called "cultured" or "synthetic" or "in vitro" meat could in theory be constructed with different characteristics and be produced faster and more efficiently than traditional meat. The technique to generate cultured muscle tissues from stem cells was described long ago, but has not yet been developed for the commercial production of cultured meat products. The technology is at an early stage and prerequisites of implementation include a reasonably high level of consumer acceptance, and the development of commercially-viable means of large scale production. Recent advancements in tissue culture techniques suggest that production may be economically feasible, provided it has physical properties in terms of colour, flavour, aroma, texture and palatability that are comparable to conventional meat. Although considerable progress has been made during recent years, important issues remain to be resolved, including the characterization of social and ethical constraints, the fine-tuning of culture conditions, and the development of culture media that are cost-effective and free of animal products. Consumer acceptance and confidence in in vitro produced cultured meat might be a significant impediment that hinders the marketing process.     

Evaluation of dietary protein and lipid requirements of two-banded seabream (Diplodus vulgaris) cultured in a recirculating aquaculture system

The objective of this study is to investigate the effects of dietary protein and lipid levels on the growth performance and bioeconomic benefits of two-banded seabream (Diplodus vulgaris) juveniles, a candidate species for aquaculture sector. Eight experimental diets were formulated with four protein (50, 45, 40 and 35 %) levels for each of the two lipid levels (15 and 10 %). Triplicate groups of juvenile fish with an average initial body weight of ~3.64 g were reared in a recirculating aquaculture system and hand fed twice a day until satiation for a period of 60 days. In the experiment, no difference in survival rate was found between the different groups. Relative growth rate (RGR), specific growth rate (SGR), feed conversion ratio (FCR) and daily feed intake were not significantly affected by increasing protein and/or lipid treatments in this present study. However, the RGR, SGR and FCR values showed slightly better efficiency in the experimental group (35/15) fed with lower protein content (35 %) and higher lipid level (15 %) compared with those fed other diets. According to bioeconomic analyses results, the diet with the 35 % protein and 15 % lipid generated the best profit. The results suggest that two-banded seabream can be accepted as a promising alternative species for the aquaculture industry and optimum growth of two-banded seabream fingerlings can be obtained when they are fed a diet containing 35 % crude protein and 15 % crude lipid.     

Quality Changes in Marinated Anchovy (Engraulis encrasicolus) Sauced with Olive Oil-Lemon Juice Emulsions

ABSTRACT

This study describes the potential use of olive oil-lemon juice emulsions containing different levels of lemon juice (0, 25, 35, and 50% v/v) as a flavoring, preservative, and antioxidant agent in marinated anchovy. The phenolic content and antioxidant activity of lemon juice, olive oil, and olive oil-lemon juice sauces as well as chemical, oxidative, and sensorial changes of marinade samples were analyzed. Increasing the level of lemon juice in sauces retarded the chemical and oxidative changes of marinated anchovy. However, increasing the level of lemon juice more than 35% in sauces led to a decrease in sensorial acceptability. Chemical and oxidative qualities of all the sauced samples were in the limit of deterioration during 100 days of storage. Although marinated anchovy samples treated with sauce containing 50% lemon juice had a significant inhibitor effect on chemical and oxidative deterioration, samples treated with sauce containing 35% lemon juice received the highest overall acceptability score.     

Can conventional breeding programmes provide onion varieties that are suitable for organic farming in the Netherlands?

Main stream commercial onion breeders do not select varieties for organic farming, but solely for conventional farming. Seed companies consider the organic market too small to justify investments in breeding for this sector. In order to study if their varieties also suit organic farmers’ needs we interviewed four Dutch commercial onion breeders on their breeding programme and selection criteria and compared the outcome with a variety profile composed of the priority traits of Dutch organic farmers. Breeders gave priority to the same storage and bulb quality traits that are demanded by organic farmers, because organic onions are exported to conventional supermarkets that apply the same quality standards to organic and conventional onions. However, organic farmers also need varieties that perform well in the field. Breeders give low priority to field selection. Furthermore, three of the four seed companies only breed hybrids. The cytoplasmic male sterility system used to produce these hybrids does not comply with organic principles. We conclude that at present breeders can provide varieties that meet organic farmers’ demands for storability and quality traits, but they should give higher priority to field selection to also improve required field traits. The latter will only occur, if in future the organic seed market will grow. If the organic sector wants varieties developed according to its own principles, it should either set up its own onion breeding programme or seek alliances with breeding companies that are prepared to harmonize their breeding methodology with the organic principles.     

Genotypic Characterization of Pseudomonas aeruginosa Isolated from Human and Animal Sources in Egypt

Two different techniques for the molecular typing of Pseudomonas aeruginosa were used to study the epidemiology of P. aeruginosa strains. Colonization with P. aeruginosa was studied by taking samples of human origin collected from urine, sputum samples of patients suffering from lung manifestations and patients exposed to third‐degree burns. In addition, samples of animal origin were collected from mastitic milk and lung tissues of slaughtered calves and from the internal organs of diseased chickens. Typing of 18 isolates was performed by random amplified polymorphic DNA analysis and amplified fragment length polymorphism analysis. Computer‐aided cluster analysis indicated that similar groups of related isolates were obtained by each method.     

Effect of germination on the nutritional quality of Pearl millet

Changes in proximate composition, trypsin inhibitor activity, phytic acid, tannins, in vitro protein digestibility and amino acids content of Pearl millet were investigated after germination for 5 days. Germination significantly increased protein content of pearl millet, with a parallel decrease in lipid and carbohydrates. Trypsin inhibitor activity and the phytic acid content showed significant decrease whereas tannin content increased after 5 days germination. In vitro protein digestibility （IVPD） was significantly decreased with germination, suggesting that tannins may be responsible for enzymes inhibition. Amino acid analysis revealed significant increase in essential amino acids and none essential amino acids.     

Bioprocess enhancement of feather degradation using alkaliphilic microbial mixture

1. The main aim of this work is to develop a robust method to generate a microbial mixture which can successfully degrade poultry feathers to overcome environmental problems.

2. Four different alkaliphilic microbes were isolated and shown to degrade poultry feathers.

3. Two of the isolates were phylogenetically identified as Lysinibacillus and the others were identified as Nocardiopsis and Micrococcus.

4. The best microbial co-culture for white and black feather degradation was optimised for pH, temperature and relative population of the isolates to achieve almost 96% of degradation compared with a maximum of 31% when applying each isolate individually.

5. The maximum activity of keratinase was estimated to be 1.5 U/ml after 3 d for white feathers and 0.6 U/ml after 4 d for black feathers in a basal medium containing feather as the main carbon source. Additionally, non-denaturing polyacrylamide gel electrophoresis showed 4 and 3 protease activity bands for white and black feather, respectively.

6. This study provides a robust method to develop potential new mixtures of microorganisms that are able to degrade both white and black feathers by applying a Central Composite Design.     

Optimization of Ammonia Removal from Aqueous Solution by Microwave-Assisted Air Stripping

In this study, the optimum conditions for the ammonia removal from aqueous solution by microwave-assisted air stripping have been investigated at pH 11. Ammonia solution with five different initial ammonia concentrations was prepared synthetically. The Taguchi method was applied to optimize the ammonia removal conditions. Initial ammonia concentration, air flow rate, temperature, stirring speed, microwave radiation power, and radiation time were defined as the optimization parameters. Experiments were carried out at five different levels for each operational parameter. The results of the experiments revealed that 1800 ppm of initial ammonia concentration, 7.5 L min^?1 of air flow rate, 60 °C of temperature, 500 rpm of stirring speed, and 500 W of microwave radiation power for 180 min. of microwave radiation time are optimum conditions for complete ammonia removal. In addition to present experimental data, the optimum operational conditions predicted by the balanced characteristics of orthogonal array were confirmed experimentally. Finally, the effect of optimization parameters was discussed in detail.

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Quantitative analysis and QTL mapping for agronomic and fiber traits in an RI population of upland cotton

Genetic mapping is an essential tool for cotton (Gossypium hirsutum L.) molecular breeding and application of DNA markers for cotton improvement. In this present study, we evaluated an RI population including 188 RI lines developed from 94 F₂-derived families and their two parental lines, ‘HS 46’ and ‘MARCABUCAG8US-1-88’, at Mississippi State, MS, for two years. Fourteen agronomic and fiber traits were measured. One hundred forty one (141) polymorphic SSR markers were screened for this population and 125 markers were used to construct a linkage map. Twenty six linkage groups were constructed, covering 125 SSR loci and 965 cM of overall map distance. Twenty four linkage groups (115 SSR loci) were assigned to specific chromosomes. Quantitative genetic analysis showed that the genotypic effects accounted for more than 20% of the phenotypic variation for all traits except fiber perimeter (18%). Fifty six QTLs (LOD > 3.0) associated with 14 agronomic and fiber traits were located on 17 chromosomes. One QTL associated with fiber elongation was located on linkage group LGU01. Nine chromosomes in sub-A genome harbored 27 QTLs with 10 associated with agronomic traits and 17 with fiber traits. Eight chromosomes in D sub-genome harbored 29 QTLs with 13 associated with agronomic traits and 16 with fiber traits. Chromosomes 3, 5, 12, 13, 14, 16, 20, and 26 harbor important QTLs for both yield and fiber quality compared to other chromosomes. Since this RI population was developed from an intraspecific cross within upland cotton, these QTLs should be useful for marker assisted selection for improving breeding efficiency in cotton line development. Paper number J1116 of the Mississippi Agricultural and Forestry Experiment Station, Mississippi State University, Mississippi State, MS 39762. Mention of trademark, proprietary product, or vendor does not constitute a guarantee or warranty of the product by USDA, ARS and does not imply its approval to the exclusion of other products or vendors that may also be suitable.     

The impact of staphylococcal mastitis on the level of milk IL-6, lysozyme and nitric oxide

Mammary gland secretions derived from secretory cows infected with coagulase +ve Staphylococcus spp. was examined for the expression of IL-6, production of lysozyme and NO(x). The examined cows reflected 25 cases of subclinical mastitis and 15 cases of clinically mastitic animals. The IL-6 concentration in the subclinical animals was significantly higher (30.8 ng/ml) than the clinically manifested animals (18.0 ng/ml) and the normal cows (5.2n g/ml). On the other hand the level of lysozyme although significantly higher than the normal cows (6.9 microg/ml) yet its level in the subclinical animals (11.2 microg/ml) was lower than that estimated in the clinical animals (15.6 microg/ml). Similarly, the level of NO(x) in the normal animals was found to be 5.6 microM/ml to increase to 6.2 microM/ml in the subclinical mastitic animals and to significantly increase further to 11.5 microM/ml in the clinically affected cows. These results suggest the promising use of whey IL-6, lysozyme or/and NO concentration variabilities as prognostic parameters on the degree of the commencement of mastitis in cows.