Showing papers by "Brendan Gilmore published in 2020"

Transaminases for industrial biocatalysis: novel enzyme discovery

Abstract: Transaminases (TAms) are important enzymes for the production of chiral amines for the pharmaceutical and fine chemical industries. Novel TAms for use in these industries have been discovered using a range of approaches, including activity-guided methods and homologous sequence searches from cultured microorganisms to searches using key motifs and metagenomic mining of environmental DNA libraries. This mini-review focuses on the methods used for TAm discovery over the past two decades, analyzing the changing trends in the field and highlighting the advantages and drawbacks of the respective approaches used. This review will also discuss the role of protein engineering in the development of novel TAms and explore possible directions for future TAm discovery for application in industrial biocatalysis. KEY POINTS: • The past two decades of TAm enzyme discovery approaches are explored. • TAm sequences are phylogenetically analyzed and compared to other discovery methods. • Benefits and drawbacks of discovery approaches for novel biocatalysts are discussed. • The role of protein engineering and future discovery directions is highlighted.

Novel decontamination approaches and their potential application for post-harvest aflatoxin control

Abstract: Background Aflatoxin is considered to be the most important mycotoxin in the world for human food and animal feed. Current strategies for the reduction of mycotoxins in food and feed includes both prevention and removal. It is clear that the development and implementation of novel decontamination methods is critical for the protection of human and animal health. Scope and approach This review focuses on post-harvest- biological, chemical and physical processes that could potentially be applied to aflatoxin decontamination. The application of novel technologies are reviewed in detail, as well as the advantages, disadvantages and limitations of these methods. This review investigates the potential for novel approaches to achieve aflatoxin decontamination. Key findings and conclusion The limitations that are associated with conventional methods of mycotoxin removal have led to ongoing research into alternative decontamination methods using novel technologies. The combination of fluorescence-based sorting to remove highly contaminated produce, paired with a secondary decontamination process is believed to have great potential to deliver effective reduction in aflatoxin contamination, whilst retaining the organoleptic and nutritional profile, and preventing significant food waste. Novel decontamination approaches when applied to aflatoxin decontamination are of huge interest and a growing need for global food security.

High-throughput toxicity screening of novel azepanium and 3-methylpiperidinium ionic liquids

Abstract: Ionic liquids (ILs) have been employed as potentially environmentally friendly replacements for harmful organic solvents, but have also been studied for their use in bioelectrochemical applications, such as in microbial electrochemistry for bioenergy production, or in industrial biocatalysis. For these processes, low microbial toxicity is important and there is a growing need for microbial toxicology studies for novel ILs. In this study, we report initial toxicity data for novel ILs, based on azepanium and 3-methylpiperidinium cations. Agar disc diffusion assays are used, along with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) determinations, to obtain rapid and inexpensive initial toxicity data for these novel ILs against Escherichia coli and Staphylococcus epidermidis. Many of the novel ILs characterised possess low microbial toxicity relative to well-studied ILs, highlighting their potential for further study in applications where this is a desirable property.

Safety evaluation of plasma-treated lettuce broth using in vitro and in vivo toxicity models

Abstract: Cold atmospheric plasma is a promising new non-thermal technology for improving microbiological safety and shelf-life of food products, particularly fresh produce and minimally processed fruit and vegetables. Limited research has been conducted on the safety of plasma-treated foods for human or animal consumption. This study focusses on basic safety studies by investigating lettuce broth treated with a di-electric barrier discharge plasma device as a fresh produce model in terms of in vitro cytotoxic and mutagenic effects on mammalian cells and its in vivo toxicity on Galleria mellonella larvae. Low cytotoxic effects were detected in vitro and mutagenic events were likely to be spontaneous mutations. However, a strong response of Galleria larvae to injection with plasma-treated lettuce broth was observed for 5-min treated broth, with less than 10% larvae survival. No significant effects on quality attributes such as colour were detected and only low concentrations of peroxide were generated in the broth. This study highlights the need for more detailed investigations on the impact of plasma treatment on food components and the subsequent in vitro and in vivo effects to ensure a safe implementation of plasma technology for processing of food products.