Surrogate broodstock to enhance biotechnology research and applications in aquaculture

Aquaculture is playing an increasingly important role in meeting global demands for seafood, particularly in low and middle income countries. Genetic improvement of aquaculture species has major untapped potential to help achieve this, with selective breeding and genome editing offering exciting avenues to expedite this process. However, limitations to these breeding and editing approaches include long generation intervals of many fish species, alongside both technical and regulatory barriers to the application of genome editing in commercial production. Surrogate broodstock technology facilitates the production of donor-derived gametes in surrogate parents, and comprises transplantation of germ cells of donors into sterilised recipients. There are many successful examples of intra- and inter-species germ cell transfer and production of viable offspring in finfish, and this leads to new opportunities to address the aforementioned limitations. Firstly, surrogate broodstock technology raises the opportunity to improve genome editing via the use of cultured germ cells, to reduce mosaicism and potentially enable in vivo CRISPR screens in the progeny of surrogate parents. Secondly, the technology has pertinent applications in preservation of aquatic genetic resources, and in facilitating breeding of high-value species which are otherwise difficult to rear in captivity. Thirdly, it holds potential to drastically reduce the effective generation interval in aquaculture breeding programmes, expediting the rate of genetic gain. Finally, it provides new opportunities for dissemination of tailored, potentially genome edited, production animals of high genetic merit for farming. This review focuses on the state-of-the-art of surrogate broodstock technology, and discusses the next steps for its applications in research and production. The integration and synergy of genomics, genome editing, and reproductive technologies have exceptional potential to expedite genetic gain in aquaculture species in the coming decades

Recent advances in γ-aminobutyric acid (GABA) properties in pulses: An overview

Beans, peas, and lentils are all types of pulses that are extensively used as foods around the world due to their beneficial effects on human health including their low glycemic index, cholesterol lowering effects, ability to decrease the risk of heart diseases and their protective effects against some cancers. These health benefits are a result of their components such as bioactive proteins, dietary fibers, slowly digested starches, minerals and vitamins, and bioactive compounds. Among these bioactive compounds, γ-aminobutyric acid (GABA), a non-proteinogenic amino acid with numerous reported health benefits (e.g. anti-diabetic and hypotensive effects, depression and anxiety reduction) is of particular interest. GABA is primarily synthesized in plant tissues by the decarboxylation of L-glutamic acid in the presence of glutamate decarboxylase (GAD). It is widely reported that during various processes including enzymatic treatment, gaseous treatment (e.g. with carbon dioxide), and fermentation (with lactic acid bacteria), GABA content increases in the plant matrix. The objective of this review paper is to highlight the current state of knowledge on the occurrence of GABA in pulses with special focus on mechanisms by which GABA levels are increased and the analytical extraction and estimation methods for this bioactive phytochemical

Sorption of cadmium (II) ion from aqueous solution onto sweet potato (Ipomoea batatas L.) peel adsorbent:characterisation, kinetic and isotherm studies

Sweet potato peels was used for the removal of Cd (II) from aqueous solutions. The residue was characterised using SEM, EDX, XRF, N2 BET, TGA and ATR-FTIR. Sorption of Cd (II) was carried out by varying pH, contact time and initial ion concentration at 25 °C and the results showed a strong dependence of the ion removal on the adsorbate pH with optimum observed at pH 7. Kinetics of Cd (II) sorption indicates optimum time of 180 min and the removal of Cd (II) occurred via a fast initial uptake. This was modelled using the pseudo first, pseudo-second and intraparticle diffusion models. The pseudo-first order gave a better description of the uptake kinetics than the pseudo-second order model with an r2 value of 0.99. The intraparticle-diffusion model showed that sorption had multi-linear steps indicating that the intraparticle-diffusion is not the only rate controlling step in Cd (II) sorption. FTIR analysis of the PTPS before and after adsorption of Cd (II) indicates that some functional groups such as hydroxyl, carbonyl and carboxylate groups may be involved in metal ion sorption. Isotherm modelling of Cd (II) sorption was carried out using the Langmuir and Freundlich isotherms using a non-linear optimisation. The Langmuir isotherm gave a better fit for Cd (II) sorption and maximum loading capacity (qmax) was 18 mg g−1 with an isotherm constant of 5.21 × 10−3 l mg−1 and r2 value of 0.99 at 25 °C. Hence, the PTPS residue was found to be a promising adsorbent for Cd (II) removal from aqueous streams