Saskatchewan Research Council (Canada)

ABSTRACT Sixteen commercially wet‐extracted protein isolates and 13 commercially air‐classified protein concentrates were evaluated for their particle size, physicochemical properties (protein solubility, differential scanning calorimetry, surface hydrophobicity, and surface charge) and functional properties (water holding capacity, oil absorption capacity, emulsifying capacity and stability, foaming capacity and stability, and least gelling concentration). Protein concentrates exhibited lower average values for particle size, surface charge, surface hydrophobicity, and water holding capacity, but higher values for oil absorption capacity, protein solubility, emulsion capacity and stability, as well as foaming capacity and stability, compared to protein isolates. Intensive processing appeared to denature proteins in most isolates, leading to reduced functional properties. Changes in pH and the addition of 2% NaCl influenced the properties of both protein isolates and concentrates. Protein solubility, emulsion capacity and stability, and foaming stability of the protein samples were superior at pH 10, followed by pH 3. The addition of 2% NaCl enhanced foaming capacity and reduced the least gelling concentration. A significant interaction between sample and treatment conditions ( p < 0.001) in protein isolates and protein concentrates was observed. Crop type differences in protein solubility, oil emulsion capacity and foaming stability of protein concentrates under certain conditions were detected using maximum likelihood factor analysis (MFLA). However, these differences were not evident in protein isolates, possibly due to more variable processing conditions.

Large genetic engineering constructs often face limitations in DNA element addition or replacement due to lack of unique endonuclease recognition sites. Traditional restriction resistance methods can identify CRISPR-induced mutants efficiently, but CRISPR target sites rarely contain suitable restriction motifs. Here, we demonstrate the use of SpCas9 combined with custom synthesised sgRNAs to linearize large plasmid constructs, enabling DNA element incorporation via seamless cloning methods. Additionally, SpCas9 and custom sgRNAs were used to digest target gene amplicons for effective genotyping of CRISPR-edited mutants, allowing us to distinguish between wild-type, heterozygous, and biallelic variants. This approach provides a straightforward, highly flexible method for modifying large plasmid constructs and screening CRISPR-induced edits.

Emiliania huxleyi is a marine microalga playing a significant ecological and biogeochemical role in oceans. It can produce several polyunsaturated fatty acids (PUFAs), such as docosahexaenoic acid (DHA, 22:6-4,7,10,13,16,19) and octadecapentaenoic acid (OPA, 18:5-3,6,9,12,15), providing a primary source for nutritionally important ω3 PUFAs in the marine food chain. However, the biosynthesis of these PUFAs in this organism is not well understood. In this study, a full length plastidial ω3 desaturase cDNA (EhN3) was cloned from this alga. Heterologous expression of EhN3 with and without the chloroplast targeting peptide (cTP) in cyanobacterium Synechococcus elongatus showed that it possessed high desaturation activity toward C18-ω6 PUFAs, linoleic acid (LA, 18:2-9,12), γ-linolenic acid (GLA, 18:3-6,9,12), and C20-ω6 PUFAs, dihomo-γ-linolenic acid (DGLA, 20:3-8,11,14) and arachidonic acid (ARA, 20:4-5,8,11,14) that were exogenously supplied. Desaturation efficiency could reach almost 100% in a time course. On the other hand, when expressed in Saccharomyces cerevisiae, EhN3 with and without cTP did not exhibit any activity. Lipid analysis of Synechococcus transformants expressing EhN3 showed that it utilized galactolipids as substrates. Transcriptional expression analysis revealed that the expression of the gene increased while the growth temperature decreased, which was correlated with the increased production of ω3-PUFAs, particularly OPA. This is the first report of a plastidial ω3 desaturase from microalgae that can effectively introduce an ω3 double bond into both C18-ω6 and C20-ω6 PUFAs. EhN3 might also be one of the key enzymes involved in the biosynthesis of OPA in E. huxleyi through the plastidial aerobic pathway.

Fermentation of pulses as a clean processing technique has been reported to have a favorable impact on the functional and nutritional quality of the starting materials. Compared to commonly fermented pulses such as peas and chickpeas, limited information is available on the effect of fermentation on lentils, especially when using a high protein isolate (>80% protein) as compared to seeds or flours. Therefore, in the present work, lentil protein isolate was used as a feedstock for submerged fermentation with Aspergillus niger, Aspergillus oryzae, or Lactobacillus plantarum. After 48h, the samples showed increased protein content with enhanced solubility and oil-holding capacity. Controlled fermentation, as opposed to spontaneous fermentation, maintained the high foaming capacity; however, all fermented samples had lower foam and emulsion stabilizing properties and reduced water-holding capacity compared to the control. The fermented proteins were also less digestible, possibly due to an increase in phenolics and saponins. New volatile compounds were identified in fermented samples that show promise for improved sensory attributes. Significant differences were observed in specific quality attributes depending on the microbial strain used. Further research is required to better understand the fermentative metabolism of microbial communities when provided high-protein lentil ingredients as growth substrates. PRACTICAL APPLICATION: Fermented lentil protein isolate has promising flavor profiles that may improve its sensory properties for food application.

Transcription factors (TFs) are diverse groups of regulatory proteins. Through their specific binding domains, TFs bind to their target genes and regulate their expression, therefore TFs play important roles in various growth and developmental processes. Plant embryogenesis is a highly regulated and intricate process during which embryos arise from various sources and undergo development; it can be further divided into zygotic embryogenesis (ZE) and somatic embryogenesis (SE). TFs play a crucial role in the process of plant embryogenesis with a number of them acting as master regulators in both ZE and SE. In this review, we focus on the master TFs involved in embryogenesis such as BABY BOOM (BBM) from the APETALA2/Ethylene-Responsive Factor (AP2/ERF) family, WUSCHEL and WUSCHEL-related homeobox (WOX) from the homeobox family, LEAFY COTYLEDON 2 (LEC2) from the B3 family, AGAMOUS-Like 15 (AGL15) from the MADS family and LEAFY COTYLEDON 1 (LEC1) from the Nuclear Factor Y (NF-Y) family. We aim to present the recent progress pertaining to the diverse roles these master TFs play in both ZE and SE in Arabidopsis, as well as other plant species including crops. We also discuss future perspectives in this context.

Abstract Background and ObjectivesThere has been a significant increase in the use of fermentation for protein modification by the food industry. This research aimed to investigate the use of solid‐state fermentation (SSF) by Aspergillus oryzae NRRL 5590 on pea and navy bean protein isolates (PPI and NBPI, respectively) to enhance their physicochemical and functional properties.FindingsThe impact of fermentation was more profound on PPI than NBPI with a higher degree of hydrolysis achieved for the former (9.3% vs. 4.4%). Fermented PPI had significantly increased protein content, surface charge and hydrophobicity, solubility, and foaming properties, but decreased emulsion stability. For NBPI, modifications were only observed for surface hydrophobicity and water hydration capacity (WHC), which both increased after fermentation. Overall, navy bean proteins were less susceptible to protein hydrolysis than pea proteins upon fermentation, possibly due to the phaseolin protein in navy bean.ConclusionsIn summary, fermentation may be used to enhance the solubility and foaming properties of PPI and WHC of NBPI for their use as ingredients in applications where such higher functionalities are favorable.Significance and NoveltyThe results provide insights into pulse protein modification by bioprocessing, specifically fermentation, and opportunities for potential value‐added applications for pea and navy bean proteins.

Horizontal gene transfer by plasmids can confer metabolic capabilities that expand a host cell’s niche. Yet, it is less understood whether the coalescence of specialized catabolic functions, antibiotic resistances and metal resistances on plasmids provides synergistic benefits. In this study, we report whole-genome assembly and phenotypic analysis of five Salmonella enterica strains isolated in the 1980s from milk powder in Munich, Germany. All strains exhibited the unusual phenotype of lactose-fermentation and encoded either of two variants of the lac operon. Surprisingly, all strains encoded the mobilized colistin resistance gene 9 (mcr-9), long before the first report of this gene in the literature. In two cases, the mcr-9 gene and the lac locus were linked within a large gene island that formed an IncHI2A-type plasmid in one strain but was chromosomally integrated in the other strain. In two other strains, the mcr-9 gene was found on a large IncHI1B/IncP-type plasmid, whereas the lac locus was encoded on a separate chromosomally integrated plasmidic island. The mcr-9 sequences were identical and genomic contexts could not explain the wide range of colistin resistances exhibited by the Salmonella strains. Nucleotide variants did explain phenotypic differences in motility and exopolysaccharide production. The observed linkage of mcr-9 to lactose metabolism, an array of heavy-metal detoxification systems, and other antibiotic resistance genes may reflect a coalescence of specialized phenotypes that improve the spread of colistin resistance in dairy facilities, much earlier than previously suspected.