Enteric methane emission reduction potential of natural feed supplements in ewe diets

Research into the potential use of various dietary feed supplements to reduce methane (CH4) production from ruminants has proliferated in recent years. In this study, two 8-wk long experiments were conducted with mature ewes and incorporated the use of a variety of natural dietary feed supplements offered either independently or in combination. Both experiments followed a randomized complete block design. Ewes were offered a basal diet in the form of ad libitum access to grass silage supplemented with 0.5 kg concentrates/ewe/d. The entire daily dietary concentrate allocation, incorporating the respective feed supplement, was offered each morning, and this was followed by the daily silage allocation. In experiment 1, the experimental diets contained 1) no supplementation (CON), 2) Ascophyllum nodosum (SW), 3) A. nodosum extract (EX1), 4) a blend of garlic and citrus extracts (GAR), and 5) a blend of essential oils (EO). In experiment 2, the experimental diets contained 1) no supplementation (CON), 2) A. nodosum extract (EX2), 3) soya oil (SO), and 4) a combination of EX2 and SO (EXSO). Twenty ewes per treatment were individually housed during both experiments. Methane was measured using portable accumulation chambers. Rumen fluid was collected at the end of both experiments for subsequent volatile fatty acid (VFA) and ammonia analyses. Data were analyzed using mixed models ANOVA (PROC MIXED, SAS v9.4). Statistically significant differences between treatment means were considered when P < 0.05. Dry matter intake was not affected by diet in either experiment (P > 0.05). Ewes offered EO tended to have an increased feed:gain ratio relative to CON (P < 0.10) and SO tended to increase the average daily gain (P < 0.10) which resulted in animals having a higher final body weight (P < 0.05) than CON. Ewes offered EX1 and SO emitted 9% less CH4 g/d than CON. The only dietary treatment to have an effect on rumen fermentation variables relative to CON was SW, which enhanced total VFA production (P < 0.05). In conclusion, the A. nodosum extract had inconsistent results on CH4 emissions whereby EX1 reduced CH4 g/d while EX2 had no mitigating effect on CH4 production, likely due to the differences in PT content reported for EX1 and EX2. SO was the only dietary feed supplement assessed in the current study that enhanced animal performance whilst mitigating daily CH4 production.

Comparison of Lipid Composition between Quasipaa spinosa Oil and Rana catesbeiana Oil and Its Effect on Lipid Accumulation in Caenorhabditis elegans

Frog oil has been recognized for its nutritional and medicinal value. However, there is limited research on the role of frog oil in preventing obesity. In this study, we aimed to investigate the lipid composition of Quasipaa spinosa oil (QSO) and Rana catesbeiana oil (RCO) using lipidomics analysis. We compared the lipid accumulation effects of these two kinds of frog oils and soybean oil (SO) in Caenorhabditis elegans (C. elegans). Additionally, we determined the gene expression related to lipid metabolism and used the nhr-49 mutant (RB1716) and sir-2.1 mutant (VC199) for validation experiments. The results showed that the lipid composition of QSO and RCO was significantly different (p < 0.05), and QSO was rich in more polyunsaturated fatty acids (PUFAs). After feeding C. elegans, the lipid accumulation of the QSO group was the lowest among the three dietary oil groups. In addition, compared with RCO and SO, QSO significantly inhibited the production of malondialdehyde (MDA) and increased the activity of superoxide dismutase (SOD). The effects of three kinds of dietary oils on the fatty acid composition of C. elegans were significantly different. Compared with SO and RCO, QSO significantly up-regulated (p < 0.05) the expression of sir-2.1 and ech-1 genes. The results showed that QSO might reduce lipid accumulation through the SIRT1 and nuclear hormone signaling pathways. Such a situation was verified experimentally by the nhr-49 mutant (RB1716) and sir-2.1 mutant (VC199). This study proposed a new functional oil, laying the groundwork for developing functional foods from Quasipaa spinosa.

Gamma-rays induced mutations increase soybean oil and protein contents

Mutation breeding is one of the effective techniques used for improving desired traits such as yield quality and quantity in economic crops. The present study aims to develop oil and protein contents in addition to high yield attributes in soybean using gamma rays as a mutagen. Seeds of the soybean genotypes Giza 21, Giza 22, Giza 82, Giza 83 and 117 were treated with gamma rays doses 50, 100, 200 and 300 Gy. Plants were then scored based on morphological parameters correlated with yield quantity including plant height, seed weight and valuable protein and oil contents. Mutant lines exhibiting the highest yield attributes were selected and used as parents for M2 generation. The M2 progeny was further assessed based on their ability to maintain their yield attributes. Twenty mutant lines were selected and used as M3 lines. The yield parameters inferred a positive effect of gamma irradiation on the collected M3 mutant lines compared to their parental genotypes. 100 Gy of gamma rays gave the highest effect on the number of pods, branches and seeds per plant in addition to protein content, while 200 Gy was more effective in increasing plant height, number of pods per plant, and oil content. Six mutant lines scored the highest yield parameters. Further assessment inferred an inverse relationship between oil and protein content in most of the tested cultivars with high agronomic features. However, four mutant lines recorded high content of oil and protein besides their high seed yield as well, which elect them as potential candidates for large-scale evaluation. The correlation among examined parameters was further confirmed via principal component analysis (PCA), which inferred a positive correlation between the number of pods, branches, seeds, and seed weight. Conversely, oil and protein content were inversely correlated in most of yielded mutant lines. Together, those findings introduce novel soybean lines with favorable agronomic traits for the market. In addition, our research sheds light on the value of using gamma rays treatment in enhancing genetic variability in soybean and improving oil, protein contents and seed yield.

Effects of soybean oil exposure on the survival, reproduction, biochemical responses, and gut microbiome of the earthworm Eisenia fetida

With increasing production of kitchen waste, cooking oil gradually enters the soil, where it can negatively affect soil fauna. In this study, we explored the effects of soybean oil on the survival, growth, reproduction, tissue structure, biochemical responses, mRNA expression, and gut microbiome of earthworms (Eisenia fetida). The median lethal concentration of soybean oil was found to be 15.59%. Earthworm growth and reproduction were significantly inhibited following exposure to a sublethal concentration of soybean oil (1/3 LC50, 5.2%). The activity of the antioxidant enzymes total superoxide dismutase (T-SOD), peroxidase (POD), and catalase (CAT) were affected under soybean oil exposure. The glutathione (GSH) content decreased significantly, whereas that of the lipid peroxide malondialdehyde (MDA) increased significantly after soybean oil exposure. mRNA expression levels of the SOD, metallothionein (MT), lysenin and lysozyme were significantly upregulated. The abundance of Bacteroides species, which are related to mineral oil repair, and Muribaculaceae species, which are related to immune regulation, increased within the earthworm intestine. These results indicate that soybean oil waste is toxic to earthworms. Thus, earthworms deployed defense mechanisms involving antioxidant system and gut microbiota for protection against soybean oil exposure-induced stress.

Glycerol monolaurate improved intestinal barrier, antioxidant capacity, inflammatory response and microbiota dysbiosis in large yellow croaker (Larimichthys crocea) fed with high soybean oil diets

Glycerol monolaurate (GML) is a potential candidate for regulating metabolic syndrome and inflammatory response. However, the role of GML in modulating intestinal health in fish has not been well determined. In this study, a 70-d feeding trial was conducted to evaluate the effect of GML on intestinal barrier, antioxidant capacity, inflammatory response and microbiota community of large yellow croaker (13.05 ± 0.09 g) fed with high level soybean oil (SO) diets. Two basic diets with fish oil (FO) or SO were formulated. Based on the SO group diet, three different levels of GML 0.02% (SO0.02), 0.04% (SO0.04) and 0.08% (SO0.08) were supplemented respectively. Results showed that intestinal villus height and perimeter ratio were increased in SO0.04 treatment compared with the SO group. The mRNA expressions of intestinal physical barrier-related gene odc and claudin-11 were significantly up-regulated in different addition of GML treatments compared with the SO group. Fish fed SO diet with 0.04% GML addition showed higher activities of acid phosphatase and lysozyme compared with the SO group. The content of malonaldehyde was significantly decreased and activities of catalase and superoxide dismutase were significantly increased in 0.02% and 0.04% GML groups compared with those in the SO group. The mRNA transcriptional levels of inflammatory response-related genes (il-1β, il-6, tnf-α and cox-2) in 0.04% GML treatment were notably lower than those in the SO group. Meanwhile, sequencing analysis of bacterial 16S rRNA V4-V5 region showed that GML addition changed gut microbiota structure and increased alpha diversity of large yellow croaker fed diets with a high level of SO. The correlation analysis results indicated that the change of intestinal microbiota relative abundance strongly correlated with intestinal health indexes. In conclusion, these results demonstrated that 0.02%-0.04% GML addition could improve intestinal morphology, physical barrier, antioxidant capacity, inflammatory response and microbiota dysbiosis of large yellow croaker fed diets with a high percentage of SO.

Metabolite analysis of soybean oil on promoting astaxanthin production of Phaffia rhodozyma

BACKGROUND

Astaxanthin is a carotenoid with strong antioxidant property. In addition, it has anti-cancer, anti-tumor, anti-inflammatory and many other functions. The micro-organisms that mainly produce astaxanthin are Haematococcus pluvialis and Phaffia rhodozyma. Compared with H. pluvialis, P. rhodozyma has shorter fermentation cycle and easier to control culture conditions, but the yield of astaxanthin in P. rhodozyma is low. This article studied how to improve the astaxanthin production of P. rhodozyma.

RESULTS

The results showed that when 10 mL L^-1 soybean oil was added to the culture medium, astaxanthin production increased significantly, reaching 7.35 mg L^-1 , which was 1.4 times that of the control group, and lycopene and β-carotene contents also increased significantly. Through targeted metabolite analysis, the fatty acids in P. rhodozyma significantly increased under the soybean oil stimulation, especially the fatty acids closely related to the formation of astaxanthin esters, included palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1n9), linoleic acid (C18:2n6), α-linolenic acid (C18:3n3) and γ-linolenic acid (C18:3n6), thereby increasing the astaxanthin esters content.

CONCLUSION

It showed that the addition of soybean oil can promote the accumulation of astaxanthin by promoting the increase of astaxanthin ester content. © 2022 Society of Chemical Industry.

Identification of GmGPATs and their effect on glycerolipid biosynthesis through seed-specific expression in soybean

BACKGROUND

Genetic improvement of soybean oil content depends on in-depth study of the glycerolipid biosynthesis pathway. The first acylation reaction catalysed by glycerol-3-phosphate acyltransferase (GPAT) is the rate-limiting step of triacylglycerol biosynthesis. However, the genes encoding GPATs in soybean remain unknown.

METHODS

We used a novel yeast genetic complementation system and seed-specific heterologous expression to identify GmGPAT activity and molecular function in glycerolipid biosynthesis.

RESULTS

Sixteen GmGPAT genes were cloned by reverse transcription-PCR for screening in yeast genetic complementation. The results showed that GmGPAT9-2 could restore the conditional lethal double knockout mutant strain ZAFU1, and GmGPAT1-1 exhibited low acyltransferase activity in serial dilution assays. In addition, the spatiotemporal expression pattern of GmGPAT9-2 exhibited tissue specificity in leaves, flowers and seeds at different developmental stages. Furthermore, both the proportion of arachidic acid and erucic acid were significantly elevated in Arabidopsis thaliana transgenic lines containing the seed-specific GmGPAT9-2 compared wild type, but the oil content was not affected.

CONCLUSION

Together, our results provide reference data for future engineering of triacylglycerol biosynthesis and fatty acid composition improvement through GPATs in soybean.

The effects of maternal fish oil supplementation rich in n-3 PUFA on offspring-broiler growth performance, body composition and bone microstructure

This study evaluated the effects of maternal fish oil supplementation rich in n-3 PUFA on the performance and bone health of offspring broilers at embryonic development stage and at market age. Ross 708 broiler breeder hens were fed standard diets containing either 2.3% soybean oil (SO) or fish oil (FO) for 28 days. Their fertilized eggs were collected and hatched. For a pre-hatch study, left tibia samples were collected at 18 days of incubation. For a post-hatch study, a total of 240 male chicks from each maternal treatment were randomly selected and assigned to 12 floor pens and provided with the same broiler diets. At 42 days of age, growth performance, body composition, bone microstructure, and expression of key bone marrow osteogenic and adipogenic genes were evaluated. One-way ANOVA was performed, and means were compared by student’s t-test. Maternal use of FO in breeder hen diet increased bone mineral content (p < 0.01), bone tissue volume (p < 0.05), and bone surface area (p < 0.05), but decreased total porosity volume (p < 0.01) during the embryonic development period. The FO group showed higher body weight gain and feed intake at the finisher stage than the SO group. Body composition analyses by dual-energy X-ray absorptiometry showed that the FO group had higher fat percentage and higher fat mass at day 1, but higher lean mass and total body mass at market age. The decreased expression of key adipogenic genes in the FO group suggested that prenatal FO supplementation in breeder hen diet suppressed adipogenesis in offspring bone marrow. Furthermore, no major differences were observed in expression of osteogenesis marker genes, microstructure change in trabecular bone, or bone mineral density. However, a significant higher close pores/open pores ratio suggested an improvement on bone health of the FO group. Thus, this study indicates that maternal fish oil diet rich in n-3 PUFA could have a favorable impact on fat mass and skeletal integrity in broiler offspring.

Overexpression of Soybean GmWRI1a Stably Increases the Seed Oil Content in Soybean

WRINKLED1 (WRI1), an APETALA2/ethylene-responsive-element-binding protein (AP2/EREBP) subfamily transcription factor, plays a crucial role in the transcriptional regulation of plant fatty acid biosynthesis. In this study, GmWRI1a was overexpressed in the soybean cultivar 'Dongnong 50' using Agrobacterium-mediated transformation to generate three transgenic lines with high seed oil contents. PCR and Southern blotting analysis showed that the T-DNA was inserted into the genome at precise insertion sites and was stably inherited by the progeny. Expression analysis using qRT-PCR and Western blotting indicated that GmWRI1a and bar driven by the CaMV 35S promoter were significantly upregulated in the transgenic plants at different developmental stages. Transcriptome sequencing results showed there were obvious differences in gene expression between transgenic line and transgenic receptor during seed developmental stages. KEGG analysis found that the differentially expressed genes mainly annotated to metabolic pathways, such as carbohydrated metabolism and lipid metabolism. A 2-year single-location field trial revealed that three transgenic lines overexpressing GmWRI1a (GmWRI1a-OE) showed a stable increase in seed oil content of 4.97-10.35%. Importantly, no significant effect on protein content and yield was observed. Overexpression of GmWRI1a changed the fatty acid composition by increasing the linoleic acid (C18:2) content and decreasing the palmitic acid (C16:0) content in the seed. The three GmWRI1a-OE lines showed no significant changes in agronomic traits. The results demonstrated that the three GmWRI1a overexpression lines exhibited consistent increases in seed oil content compared with that of the wild type and did not significantly affect the seed yield and agronomic traits. The genetic engineering of GmWRI1a will be an effective strategy for the improvement of seed oil content and value in soybean.

Reduced palmitic acid content in soybean as a result of mutation in FATB1a

The fatty acid component of commodity soybean seeds typically consists of approximately 12-15% saturated fatty acids in the form of palmitic acid and stearic acid. An important goal in soybean breeding is the reduction of saturated fats, in order to produce healthier vegetable oils for food applications. Genetic approaches have been instrumental in reducing levels of palmitic acid, which is the most abundant saturated fat in soybean seeds. In this study we describe a new mutant allele of the FATB1a gene that encodes a palmitoyl-acyl carrier protein thioesterase. The mutation is expected to result in early termination of the FATB1A protein and mutant seeds carrying this allele contain 5.5% palmitic acid. This new allele can be introduced into conventional soybean lines, alone or in combination with other modifications to generate soybean lines with improved oil composition.

Quantitative proteomic and lipidomics analyses of high oil content GmDGAT1-2 transgenic soybean illustrate the regulatory mechanism of lipoxygenase and oleosin

KEY MESSAGE

Proteomic and lipidomics analyses of WT and GmDGAT1-2 transgenic soybeans showed that GmDGAT1-2 over-expression induced lipoxygenase down-regulatation and oleoin up-regulatation, which significantly changed the compositions and total fatty acid. The main goal of soybean breeding is to increase the oil content. Diacylglycerol acyltransferase (DGAT) is a key rate-limiting enzyme in fatty acid metabolism and may regulate oil content. Herein, 10 GmDGAT genes were isolated from soybean and transferred into wild-type (WT) Arabidopsis. The total fatty acid was 1.2 times higher in T3 GmDGAT1-2 transgenic Arabidopsis seeds than in WT. Therefore, GmDGAT1-2 was transferred into WT soybean (JACK), and four T3 transgenic soybean lines were obtained. The results of high-performance gas chromatography and Soxhlet extractor showed that, compared with those of JACK, oleic acid (18:1), and total fatty acid levels in transgenic soybean plants were much higher, but linoleic acid (18:2) was lower than WT. Palmitic acid (16:0), stearic acid (18:0), and linolenic acid (18:3) were not significantly different. For mechanistic studies, 436 differentially expressed proteins (DEPs) and 180 differentially expressed metabolites (DEMs) were identified between WT (JACK) and transgenic soybean pods using proteomic and lipidomics analyses. Four lipoxygenase proteins were down-regulated in linoleic acid metabolism while four oleosin proteins were up-regulated in the final oil formation. The results showed an increase in the total fatty acid and 18:1 composition, and a decrease in the 18:2 composition of fatty acid. Our study brings new insights into soybean genetic transformation and the deep study of molecular mechanism that changes the total fatty acid, 18:1, and 18:2 compositions in GmDGAT1-2 transgenic soybean.

Circular RNAs acting as ceRNAs mediated by miRNAs may be involved in the synthesis of soybean fatty acids

Soybean oil is composed of fatty acids and glycerol. The content and composition of fatty acids partly determine the quality of soybean seeds. Circular RNAs (circRNAs) are endogenous non-coding RNAs that competitively bind to microRNAs (miRNAs) through miRNA recognition elements, thereby acting as sponges to regulate the expression of target genes. Although circRNAs have been identified previously in soybean, only their expression has been investigated without exploration of the competitive endogenous RNAs (ceRNAs) network of circRNAs-miRNAs-mRNAs. In this study, circRNAs in immature pods of a low linolenic acid soybean Mutant 72' (MT72) and the wild-type control 'Jinong 18' (JN18) were systematically identified and analyzed at 30 and 40 days after flowering using high-throughput sequencing technology. We identified 6377 circRNAs, of which 114 were differentially expressed. Gene ontology and KEGG pathway analyses of targeted mRNAs in the ceRNAs network indicated that the differentially expressed circRNAs may be involved in fatty acid transport, suggesting that circRNAs may play a post-transcriptional regulatory role in soybean oil synthesis. This study provides a foundation for future exploration of the function of circRNAs in soybean and presents novel insights to guide further studies of plant circRNAs.

TILLING-by-Sequencing+ to Decipher Oil Biosynthesis Pathway in Soybeans: A New and Effective Platform for High-Throughput Gene Functional Analysis

Reverse genetic approaches have been widely applied to study gene function in crop species; however, these techniques, including gel-based TILLING, present low efficiency to characterize genes in soybeans due to genome complexity, gene duplication, and the presence of multiple gene family members that share high homology in their DNA sequence. Chemical mutagenesis emerges as a genetically modified-free strategy to produce large-scale soybean mutants for economically important traits improvement. The current study uses an optimized high-throughput TILLING by target capture sequencing technology, or TILLING-by-Sequencing+ (TbyS+), coupled with universal bioinformatic tools to identify population-wide mutations in soybeans. Four ethyl methanesulfonate mutagenized populations (4032 mutant families) have been screened for the presence of induced mutations in targeted genes. The mutation types and effects have been characterized for a total of 138 soybean genes involved in soybean seed composition, disease resistance, and many other quality traits. To test the efficiency of TbyS+ in complex genomes, we used soybeans as a model with a focus on three desaturase gene families, GmSACPD, GmFAD2, and GmFAD3, that are involved in the soybean fatty acid biosynthesis pathway. We successfully isolated mutants from all the six gene family members. Unsurprisingly, most of the characterized mutants showed significant changes either in their stearic, oleic, or linolenic acids. By using TbyS+, we discovered novel sources of soybean oil traits, including high saturated and monosaturated fatty acids in addition to low polyunsaturated fatty acid contents. This technology provides an unprecedented platform for highly effective screening of polyploid mutant populations and functional gene analysis. The obtained soybean mutants from this study can be used in subsequent soybean breeding programs for improved oil composition traits.

CRISPR/Cas9-Mediated Knockout of GmFATB1 Significantly Reduced the Amount of Saturated Fatty Acids in Soybean Seeds

Soybean (Glycine max) oil is one of the most widely used vegetable oils across the world. Breeding of soybean to reduce the saturated fatty acid (FA) content, which is linked to cardiovascular disease, would be of great significance for nutritional improvement. Acyl-acyl carrier protein thioesterases (FATs) can release free FAs and acyl-ACP, which ultimately affects the FA profile. In this study, we identified a pair of soybean FATB coding genes, GmFATB1a and GmFATB1b. Mutants that knock out either or both of the GmFATB1 genes were obtained via CRISPR/Cas9. Single mutants, fatb1a and fatb1b, showed a decrease in leaf palmitic and stearic acid contents, ranging from 11% to 21%. The double mutant, fatb1a:1b, had a 42% and 35% decrease in palmitic and stearic acid content, displayed growth defects, and were male sterility. Analysis of the seed oil profile revealed that fatb1a and fatb1b had significant lower palmitic and stearic acid contents, 39-53% and 17-37%, respectively, while that of the unsaturated FAs were the same. The relative content of the beneficial FA, linoleic acid, was increased by 1.3-3.6%. The oil profile changes in these mutants were confirmed for four generations. Overall, our data illustrate that GmFATB1 knockout mutants have great potential in improving the soybean oil quality for human health.

Liquid Chicken Oil Could Be a Healthy Dietary Oil

Liquid chicken oil is similar to the human lipid ratio, and is similar to the ideal fatty acids ratio suggested by Hayes, but its benefits remain unclear (Hwang, K.N.; Tung, H.P.; Shaw, H.M. J. Oleo. Sci. 69, 199-206 (2020)). Using soybean oil as a control, liquid chicken oil, coconut oil, lard oil, and olive oil, were tested on SD rats with the rodent diet 5001 plus 1% of high cholesterol addition and moderate 10 % of test oils. Positive results showed that a 10% liquid chicken oil diet reduced LDL and triglycerides, atherogenic index while increasing superoxide dismutase more than the soybean oil control (0.05 ≦ p < 0.10). Moreover, increment of hepatic endogenous glutathione peroxidase was found to be significantly different from the soybean oil control (p < 0.05). In this study, liquid chicken oil had more benefits than vegetable soybean dietary oil, with little evidence of hyperlipidemia. Comparison of the test oils with categories of fatty acids to the idea ratio SFA : MUFA : PUFA = 1 : 1.5 : 1, scored by its average weight implied a parallel trend of lipidemia and hepatic antioxidant activity to its score. It is difficult to use the test of rat to reflect human physiology, it remain 19% different of the fatty acids ratio from human ratio, however, this study reveal that the healthiness of a dietary oil seems relate well to its compatibility to the idea ratio or the host oil ratio, in this case, it is the human ratio.

Facile and Green Production of Human Milk Fat Substitute through Rhodococcus opacus Fermentation

Human milk fat substitute (HMFS) is a class of structured lipids widely used in infant formulas. Herein, HMFS was prepared by Rhodococcus opacus fermentation. The substrate oils suitable for HMFS production were coconut oil (66.1-57.5%), soybean oil (17.5-26.5%), high oleic acid sunflower oil (5.4-4.5%), Antarctic krill oil (9-9.5%), and fungal oil (2%). Six HMFSs were prepared, among which HMFS V and VI were similar to human milk fat from Chinese in terms of fatty acid composition and triacylglycerol species. The sn-2 position of HMFS was occupied by palmitic acid (49.31 and 43.48% in HMFS V and VI, respectively). The major triacylglycerols were OPL, OPO, and LPL, accounting for 15.90, 9.49, and 6.84 and 17.52, 8.44, and 8.55% in HMFS V and VI, respectively. This study is the first to prepare structured lipids intended for infant formula through fermentation, providing a novel strategy for the edible oil industry.

Genome-wide association study identifies candidate genes related to oleic acid content in soybean seeds

BACKGROUND

Soybean oil is a complex mixture of five fatty acids (palmitic, stearic, oleic, linoleic, and linolenic). Soybean oil with a high oleic acid content is desirable because this monounsaturated fatty acid improves the oxidative stability of the oil. To investigate the genetic architecture of oleic acid in soybean seeds, 260 soybean germplasms from Northeast China were collected as natural populations. A genome-wide association study (GWAS) was conducted on a panel of 260 germplasm resources.

RESULTS

Phenotypic identification results showed that the oleic acid content varied from 8.2 to 35.0%. A total of 2,311,337 single-nucleotide polymorphism (SNP) markers were obtained. GWAS analysis showed that there were many genes related to oleic acid content with a contribution rate of 7%. The candidate genes Glyma.11G229600.1 on chromosome 11 and Glyma.04G102900.1 on chromosome 4 were detected in a 2-year-long GWAS. The candidate gene Glyma.11G229600.1 showed a positive correlation with the oleic acid content, and the correlation coefficient was 0.980, while Glyma.04G102900.1 showed a negative correlation, with a coefficient of - 0.964.

CONCLUSIONS

Glyma.04G102900.1 on chromosome 4 and Glyma.11G229600.1 on chromosome 11 were detected in both analyses (2018 and 2019). Glyma.04G102900.1 and Glyma.11G229600.1 are new key candidate genes related to oleic acid in soybean seeds. These results will be useful for high-oleic soybean breeding.

Three-dimensional genetic networks among seed oil-related traits, metabolites and genes reveal the genetic foundations of oil synthesis in soybean

Although the biochemical and genetic basis of lipid metabolism is clear in Arabidopsis, there is limited information concerning the relevant genes in Glycine max (soybean). To address this issue, we constructed three-dimensional genetic networks using six seed oil-related traits, 52 lipid metabolism-related metabolites and 54 294 SNPs in 286 soybean accessions in total. As a result, 284 and 279 candidate genes were found to be significantly associated with seed oil-related traits and metabolites by phenotypic and metabolic genome-wide association studies and multi-omics analyses, respectively. Using minimax concave penalty (MCP) and smoothly clipped absolute deviation (SCAD) analyses, six seed oil-related traits were found to be significantly related to 31 metabolites. Among the above candidate genes, 36 genes were found to be associated with oil synthesis (27 genes), amino acid synthesis (four genes) and the tricarboxylic acid (TCA) cycle (five genes), and four genes (GmFATB1a, GmPDAT, GmPLDα1 and GmDAGAT1) are already known to be related to oil synthesis. Using this information, 133 three-dimensional genetic networks were constructed, 24 of which are known, e.g. pyruvate-GmPDAT-GmFATA2-oil content. Using these networks, GmPDAT, GmAGT and GmACP4 reveal the genetic relationships between pyruvate and the three major nutrients, and GmPDAT, GmZF351 and GmPgs1 reveal the genetic relationships between amino acids and seed oil content. In addition, GmCds1, along with average temperature in July and the rainfall from June to September, influence seed oil content across years. This study provides a new approach for the construction of three-dimensional genetic networks and reveals new information for soybean seed oil improvement and the identification of gene function.

Natural variation and selection in GmSWEET39 affect soybean seed oil content

Soybean (Glycine max) is a major contributor to the world oilseed production. Its seed oil content has been increased through soybean domestication and improvement. However, the genes underlying the selection are largely unknown. The present contribution analyzed the expression patterns of genes in the seed oil quantitative trait loci with strong selective sweep signals, then used association, functional study and population genetics to reveal a sucrose efflux transporter gene, GmSWEET39, controlling soybean seed oil content and under selection. GmSWEET39 is highly expressed in soybean seeds and encodes a plasma membrane-localized protein. Its expression level is positively correlated with soybean seed oil content. The variation in its promoter and coding sequence leads to different natural alleles of this gene. The GmSWEET39 allelic effects on total oil content were confirmed in the seeds of soybean recombinant inbred lines, transgenic Arabidopsis, and transgenic soybean hairy roots. The frequencies of its superior alleles increased from wild soybean to cultivated soybean, and are much higher in released soybean cultivars. The findings herein suggest that the sequence variation in GmSWEET39 affects its relative expression and oil content in soybean seeds, and GmSWEET39 has been selected to increase seed oil content during soybean domestication and improvement.

Targeted transcriptomic study of the implication of central metabolic pathways in mannosylerythritol lipids biosynthesis in Pseudozyma antarctica T-34

Pseudozyma antarctica is a nonpathogenic phyllosphere yeast known as an excellent producer of industrial lipases and mannosylerythritol lipids (MELs), which are multi-functional glycolipids. The fungus produces a much higher amount of MELs from vegetable oil than from glucose, whereas its close relative, Ustilago maydis UM521, produces a lower amount of MELs from vegetable oil. In the present study, we used previous gene expression profiles measured by DNA microarray analyses after culturing on two carbon sources, glucose and soybean oil, to further characterize MEL biosynthesis in P. antarctica T-34. A total of 264 genes were found with induction ratios and expression intensities under oily conditions with similar tendencies to those of MEL cluster genes. Of these, 93 were categorized as metabolic genes using the Eukaryotic Orthologous Groups classification. Within this metabolic category, amino acids, carbohydrates, inorganic ions, and secondary metabolite metabolism, as well as energy production and conversion, but not lipid metabolism, were enriched. Furthermore, genes involved in central metabolic pathways, such as glycolysis and the tricarboxylic acid cycle, were highly induced in P. antarctica T-34 under oily conditions, whereas they were suppressed in U. maydis UM521. These results suggest that the central metabolism of P. antarctica T-34 under oily conditions contributes to its excellent oil utilization and extracellular glycolipid production.

Effects of dietary lipid sources on growth performance and carcass traits in Pekin ducks

This study was conducted to determine the influence of dietary lipid sources on growth performance, carcass traits and taste scores in Pekin ducks. A total of 1,500 fifteen-day-old ducks (820 ± 22 g) were blocked based on body weight (BW), and randomly allotted to 3 treatments with 10 replicates of 50 birds each (25 males and 25 females). The experiment lasted for 4 wk, and dietary treatments included 3 different lipid sources (soybean oil, duck fat, and palm oil), which were evaluated in corn-soybean meal diets (3250 kcal/kg metabolizable energy and 16.5% crude protein for grower diet and 3350 kcal/kg metabolizable energy and 15.5% crude protein for finisher diet). During days 15 to 28, feeding soybean oil and palm oil diets increased (P < 0.05) body weight gain (BWG), but decreased (P < 0.05) feed intake, feed-to-gain ratio (F/G) and caloric conversion compared with duck fat. During days 29 to 42, birds fed duck fat diet had higher BWG, but lower (P < 0.05) F/G and caloric conversion than those fed soybean oil and palm oil diets. Overall, feeding soybean oil diet increased (P < 0.05) BWG and final BW, but decreased (P < 0.05) F/G compared with palm oil. Birds fed duck fat diet had higher (P < 0.05) skin, subcutaneous fat and abdominal fat yield compared with palm oil. Left breast meat yield in soybean oil group was higher (P < 0.05) than that in duck fat and palm oil groups. Birds in soybean oil group had lower (P < 0.05) roasting loss, but higher (P < 0.05) comprehensive score compared with duck fat and palm oil. In summary, birds fed soybean oil diet had the best growth performance and taste scores for roasting, whereas the duck fat was better in abdominal fat and subcutaneous fat yield than soybean oil and palm oil in Pekin ducks from 15 to 42 d of age under the same nutritional level.

Pattern analysis suggests that phosphoenolpyruvate carboxylase in maturing soybean seeds promotes the accumulation of protein

The protein and oil contents in soybean seeds are major factors in seed quality. Seed proteins and oils are synthesized from sucrose and nitrogenous compounds transported into maturing seeds. In this study, we compared changes in the activity of phosphoenolpyruvate carboxylase (PEPC) and the accumulation profiles of protein and oil in maturing seeds of two soybean cultivars, which exhibit different protein and oil contents in seeds, to determine the interrelationships of them. A principal component analysis indicated a concordance of seed PEPC activity with the protein content, but did not with the oil content. PEPC activity per seed was highest in the late maturation stage, when the physiological status of the vegetative organs drastically changed. The high-protein cultivar had higher PEPC activity compared to the low-protein cultivar. These results highlight the biological role of PEPC in the synthesis of protein, therefore it was implied that PEPC could be a biomarker in soybean breeding.Abbreviations: ANOVA: analysis of variance; DS: developmental stage; DW: dry weight; FW: fresh weight; NIR: near infrared; PEP(C): phosphoenolpyruvate (carboxylase); PC(A): principal component (analysis); S.E.: standard error; WC: water content.

Crude soybean lecithin as alternative energy source for broiler chicken diets

Two experiments were conducted to evaluate the use of crude soybean lecithin (L) as an alternative energy source in broiler feeding and to study its influence on performance, fatty acid (FA) digestibility between 9 to 11 D and 36 to 37 D, feed AME content, and the FA profile of the abdominal fat pad (AFP). A basal diet was supplemented at 3% with soybean oil (S; experiment 1) or a monounsaturated vegetable acid oil (A; experiment 2) and increasing amounts of L (1, 2, and 3%) were included in replacement. The inclusion of L did not modify performance results (P > 0.05). In starter diets, the replacement of S by L reduced feed AME content (P < 0.001) and lowered PUFA digestibility (P = 0.028), whereas in the grower-finisher phase, a blend of 2% of S and 1% of L did not modify feed AME content or FA digestibility. When L was included instead of A, no effects on feed AME value and total FA digestibility (P > 0.05) were shown in the starter phase, whereas in grower-finisher diets, a blending of 2% of A and 1% of L enhanced feed AME content (P < 0.001) and total FA digestibility (P = 0.001). The FA profile of the AFP reflected the FA composition of the diets. Crude soybean lecithin represents an alternative energy source for broiler chickens, and it can be used in growing-finishing diets in replacement of 1% S. The best option to include both alternative fats (L and A) was 2% of L with 1% of A in starter diets and 1% of L with 2% of A in grower-finisher diets because they showed positive synergic effects. The results suggest that dietary FA profile have a bigger impact on the AFP saturation degree than the different dietary lipid molecular structures.

Identifying a wild allele conferring small seed size, high protein content and low oil content using chromosome segment substitution lines in soybean

KEY MESSAGE

A wild soybean allele conferring 100-seed weight, protein content and oil content simultaneously was fine-mapped to a 329-kb region on Chromosome 15, in which Glyma.15g049200 was predicted a candidate gene. Annual wild soybean characterized with small 100-seed weight (100SW), high protein content (PRC), low oil content (OIC) may contain favourable alleles for broadening the genetic base of cultivated soybeans. To evaluate these alleles, a population composed of 195 chromosome segment substitution lines (SojaCSSLP4), with wild N24852 as donor and cultivated NN1138-2 as recurrent parent, was tested. In SojaCSSLP4, 10, 9 and 8 wild segments/QTL were detected for 100SW, PRC and OIC, respectively. Using a backcross-derived secondary population, one segment for the three traits (q100SW15, qPro15 and qOil15) and one for 100SW (q100SW18.2) were fine-mapped into a 329-kb region on chromosome 15 and a 286-kb region on chromosome 18, respectively. Integrated with the transcription data in SoyBase, 42 genes were predicted in the 329-kb region where Glyma.15g049200 showed significant expression differences at all seed development stages. Furthermore, the Glyma.15g049200 segments of the two parents were sequenced and compared, which showed two base insertions in CDS (coding sequence) in the wild N24852 comparing to the NN1138-2. Since only Glyma.15g049200 performed differential CDS between the two parents but related to the three traits, Glyma.15g049200 was predicted a pleiotropic candidate gene for 100SW, PRC and OIC. The functional annotation of Glyma.15g049200 indicated a bidirectional sucrose transporter belonging to MtN3/saliva family which might be the reason that this gene provides a same biochemical basis for 100SW, PRC and OIC, therefore, is responsible for the three traits. This result may facilitate isolation of the specific gene and provide prerequisite for understanding the other two pleiotropic QTL.

Influence of minor components on lipid bioaccessibility and oxidation during in vitro digestion of soybean oil

BACKGROUND

Minor components of edible oils could influence their evolution during in vitro digestion. This might affect the bioaccessibility of lipid nutrients and the safety of the ingested food. Bearing this in mind, the evolution of virgin and refined soybean oils, which are very similar in acyl group composition, has been studied throughout in vitro digestion using ¹ H nuclear magnetic resonance (NMR) and solid-phase microextraction-gas chromatography /mass spectrometry, focusing on lipolysis and oxidation reactions. The fate of γ-tocopherol, the main antioxidant present in soybean oil, has also been analyzed with ¹ H NMR.

RESULTS

There were no noticeable differences in lipolysis between the two oils that were studied. The extent of oxidation during digestion, which was very low in both cases, was slightly higher in the virgin type, which showed lower tocopherols and squalene concentrations than the refined one, together with a considerable abundance of free fatty acids. This can be deduced both from the appearance after digestion of conjugated hydroperoxy- and hydroxy-dienes only in the virgin oil, and from its higher levels of volatile aldehydes and 2-pentyl-furan. Under in vitro digestion conditions, the formation of epoxides seemed to be favored over other oxidation products. Finally, although some soybean oil essential nutrients like polyunsaturated fatty acids exhibited no significant degradation after digestion, γ-tocopherol concentration diminished during this process, especially in the virgin oil.

CONCLUSION

Although the minor component composition of the soybean oils did not affect lipolysis during in vitro digestion, it influenced the extent of their oxidation and γ-tocopherol bioaccessibility. © 2019 Society of Chemical Industry.

Genome-wide association study of seed protein, oil and amino acid contents in soybean from maturity groups I to IV

KEY MESSAGE

Genomic regions associated with seed protein, oil and amino acid contents were identified by genome-wide association analyses. Geographic distributions of haplotypes indicate scope of improvement of these traits. Soybean [Glycine max (L.) Merr.] protein and oil are used worldwide in feed, food and industrial materials. Increasing seed protein and oil contents is important; however, protein content is generally negatively correlated with oil content. We conducted a genome-wide association study using phenotypic data collected from five environments for 621 accessions in maturity groups I-IV and 34,014 markers to identify quantitative trait loci (QTL) for seed content of protein, oil and several essential amino acids. Three and five genomic regions were associated with seed protein and oil contents, respectively. One, three, one and four genomic regions were associated with cysteine, methionine, lysine and threonine content (g kg-1 crude protein), respectively. As previously shown, QTL on chromosomes 15 and 20 were associated with seed protein and oil contents, with both exhibiting opposite effects on the two traits, and the chromosome 20 QTL having the most significant effect. A multi-trait mixed model identified trait-specific QTL. A QTL on chromosome 5 increased oil with no effect on protein content, and a QTL on chromosome 10 increased protein content with little effect on oil content. The chromosome 10 QTL co-localized with maturity gene E2/GmGIa. Identification of trait-specific QTL indicates feasibility to reduce the negative correlation between protein and oil contents. Haplotype blocks were defined at the QTL identified on chromosomes 5, 10, 15 and 20. Frequencies of positive effect haplotypes varied across maturity groups and geographic regions, providing guidance on which alleles have potential to contribute to soybean improvement for specific regions.

Ruminal fatty acid outflow in dry cows fed different sources of linoleic acid: reticulum and omasum as alternative sampling sites to abomasum

This study was designed to determine the rumen outflow of fatty acids (FA) and biohydrogenation (BH) extent using alternative sampling sites (reticulum and omasum) to abomasum in dry cows fed different sources of FA. Four Holstein non-pregnant dry cows (≥3 parturitions, and 712 ± 125 kg BW), cannulated in the rumen and abomasum, were randomly assigned to a 4 × 4 Latin square design experiment, containing the following treatments: 1) control (CON); 2) soya bean oil (SO), dietary inclusion at 30 g/kg; 3) whole raw soya beans (WS), dietary inclusion at 160 g/kg; and 4) calcium salts of FA (CSFA), dietary inclusion at 32 g/kg. Rumen outflow of nutrients was estimated using the three markers reconstitution system (cobalt-EDTA, ytterbium chloride, and indigestible neutral detergent fibre [NDF]). Diets with FA sources decreased feed intake and increased FA intake. No differences in nutrient intake and digestibility were detected among cows fed diets supplemented with different FA sources. Diets with FA sources reduced the rumen outflow of DM and NDF, hence decreasing their passage rates. In addition, SO diet reduced the ruminal outflow of DM and NDF in comparison with WS and CSFA. Omasal sampling yielded the highest values of rumen outflow of NDF and potentially degradable NDF (pdNDF), whereas the reticular and abomasal samplings yielded intermediate and least values, respectively. The interaction effect between diet and sampling site was observed for rumen outflow of majority FA (except for C16:0, C18:0, and C18:2 trans-10, cis-12) and BH extension of C18:1 cis, C18:2, and C18:3. Calculations derived from abomasal sampling revealed that WS and CSFA diets had lower BH extent of C18:1 cis and C18:2 in comparison with SO, whereas cows fed CSFA had greater BH extent of C18:3 and lower BH extent of C18:1 cis compared to those fed WS. However, the latter results were not similar when calculations were performed based on the reticular and omasal samplings. Thus, there is evidence that neither reticular nor omasal samplings are suitable for estimating rumen outflow of FA in dry cows. In addition, WS and CSFA diets can increase the abomasal flow of polyunsaturated FA in dry cows.

Effects of dietary lipid sources on the intestinal microbiome and health of golden pompano (Trachinotus ovatus)

Replacement of fish oil (FO) with vegetable oils (VO) in diets is economically desirable for the sustainable development of the aquaculture industry. However, inflammation provoked by FO replacement limited its widely application in fish industry. In order to understand the mechanism of VO-induced inflammation, this study investigated the impact of different dietary vegetable oils on the intestinal health and microbiome in carnivorous marine fish golden pompano (Trachinotus ovatus). Three diets supplemented with fish oil (FO, rich in long-chain polyunsaturated fatty acids), soybean oil (SO, rich in 18:2n-6) and linseed oil (LO, rich in 18:3n-3), respectively, were fed on juvenile golden pompano for 8 weeks, and the intestinal histology, digestive enzymes activities, immunity and antioxidant indices as well as intestinal microbiome were determined. The results showed that dietary SO significantly impaired intestinal health, and decreased the number and height of intestinal folds, and muscle thickness, as well as the zonula occludens-1 (zo-1) mRNA expression in intestine. Moreover, the two dietary VO significantly decreased the amylase and lipase activities in intestine, and reduced the trypsin activity in the dietary SO group. Furthermore, the two VO diets increased intestinal acid phosphatase (ACP) activity, while intestinal lysozyme (LZM) activity and serum diamine oxidase (DAO) activity in the SO group were also significantly increased (P < 0.05). Analysis of the intestinal microbiota showed that the two VO diets significantly increased the abundance of intestinal potentially pathogenic bacteria (Mycoplasma and Vibrio) and decreased proportions of intestinal probiotics (Bacillus and Lactococcus), especially in the dietary SO group. These results indicate that complete replacement of FO with VO in diets would induce intestinal inflammation and impair intestinal function, which might be due to changes in intestinal microbiota profiles, and that dietary SO would have a more negative effect compared to dietary LO on intestinal health in T. ovatus.

Soybean seed physiology, quality, and chemical composition under soil moisture stress

Soybean seed quality is often determined by its constituents which are important to sustain overall nutritional aspects. The objective of this study was to investigate the effects of soil moisture stress during reproductive stage on seed quality and composition. Plants were subjected to five levels of soil moisture stresses at flowering, and yield and quality traits were examined at maturity. Seed protein, palmitic and linoleic acids, sucrose, raffinose, stachyose, N, P, K, and Ca significantly decreased whereas oil, stearic, oleic and linolenic acids, Fe, Mg, Zn, Cu, and B increased in response to soil moisture deficiency. The relationship between seed protein and oil was negatively correlated. The changes in seed constituents could be due to changes in nutrient accumulation and partitioning in soybean seeds under water stress. This information suggests the requirement of adequate soil moisture during flowering and seed formation stages to obtain the higher nutritional value of soybean seeds.

An integrated omics analysis reveals molecular mechanisms that are associated with differences in seed oil content between Glycine max and Brassica napus

BACKGROUND

Rapeseed (Brassica napus L.) and soybean (Glycine max L.) seeds are rich in both protein and oil, which are major sources of biofuels and nutrition. Although the difference in seed oil content between soybean (~ 20%) and rapeseed (~ 40%) exists, little is known about its underlying molecular mechanism.

RESULTS

An integrated omics analysis was performed in soybean, rapeseed, Arabidopsis (Arabidopsis thaliana L. Heynh), and sesame (Sesamum indicum L.), based on Arabidopsis acyl-lipid metabolism- and carbon metabolism-related genes. As a result, candidate genes and their transcription factors and microRNAs, along with phylogenetic analysis and co-expression network analysis of the PEPC gene family, were found to be largely associated with the difference between the two species. First, three soybean genes (Glyma.13G148600, Glyma.13G207900 and Glyma.12G122900) co-expressed with GmPEPC1 are specifically enriched during seed storage protein accumulation stages, while the expression of BnPEPC1 is putatively inhibited by bna-miR169, and two genes BnSTKA and BnCKII are co-expressed with BnPEPC1 and are specifically associated with plant circadian rhythm, which are related to seed oil biosynthesis. Then, in de novo fatty acid synthesis there are rapeseed-specific genes encoding subunits β-CT (BnaC05g37990D) and BCCP1 (BnaA03g06000D) of heterogeneous ACCase, which could interfere with synthesis rate, and β-CT is positively regulated by four transcription factors (BnaA01g37250D, BnaA02g26190D, BnaC01g01040D and BnaC07g21470D). In triglyceride synthesis, GmLPAAT2 is putatively inhibited by three miRNAs (gma-miR171, gma-miR1516 and gma-miR5775). Finally, in rapeseed there was evidence for the expansion of gene families, CALO, OBO and STERO, related to lipid storage, and the contraction of gene families, LOX, LAH and HSI2, related to oil degradation.

CONCLUSIONS

The molecular mechanisms associated with differences in seed oil content provide the basis for future breeding efforts to improve seed oil content.

Determination of an Optimized Weighting Factor of Liver Parenchyma for Six-point Interference Dixon Fat Percentage Imaging Accuracy in Nonalcoholic Fatty Liver Disease Rat Model

RATIONALE AND OBJECTIVES

The aim of this study was to determine the optimal weighting factor (WF) for precise quantification using six-point interference Dixon fat percentage imaging by analyzing changes in WFs of fatty acid metabolites (FMs) in high-fat-induced fatty liver disease rat model.

MATERIALS AND METHODS

Individual FM-related WFs were calculated based on concentration ratios of integrated areas of seven peak FMs with four phantom series. Ten 8-week-old male Sprague-Dawley rats were used for baseline quantification of fat in liver magnetic resonance imaging or magnetic resonance spectroscopy data. These seven lipid metabolites were then quantitatively analyzed. Spearman test was used for correlation analysis of different lipid proton concentrations. The most accurate WF for six-point interference Dixon fat percentage imaging was then determined.

RESULTS

The seven lipid resonance WF values obtained from magnetic resonance spectroscopy data for three different oils (oleic, linoleic, and soybean) were different from each other. In lipid phantoms, except for the phantom containing oleic acid, changes in FP values were significantly different when WFs were changed in six-point interference Dixon fat percentage image. The seven lipid resonance WF values for the nonalcoholic fatty liver animal model were different from human subcutaneous adipose tissue lipid WF values.

CONCLUSIONS

WF affected the calculation of six-point interference Dixon-based fat percentage imaging value in phantom experiment. If WF of liver parenchyma FM which is specific to each liver disease is applied, the accuracy of six-point interference Dixon fat percentage imaging can be further increased.

Dissecting genomic hotspots underlying seed protein, oil, and sucrose content in an interspecific mapping population of soybean using high-density linkage mapping

The cultivated [Glycine max (L) Merr.] and wild [Glycine soja Siebold & Zucc.] soybean species comprise wide variation in seed composition traits. Compared to wild soybean, cultivated soybean contains low protein, high oil, and high sucrose. In this study, an interspecific population was derived from a cross between G. max (Williams 82) and G. soja (PI 483460B). This recombinant inbred line (RIL) population of 188 lines was sequenced at 0.3× depth. Based on 91 342 single nucleotide polymorphisms (SNPs), recombination events in RILs were defined, and a high-resolution bin map was developed (4070 bins). In addition to bin mapping, quantitative trait loci (QTL) analysis for protein, oil, and sucrose was performed using 3343 polymorphic SNPs (3K-SNP), derived from Illumina Infinium BeadChip sequencing platform. The QTL regions from both platforms were compared, and a significant concordance was observed between bin and 3K-SNP markers. Importantly, the bin map derived from next-generation sequencing technology enhanced mapping resolution (from 1325 to 50 Kb). A total of five, nine, and four QTLs were identified for protein, oil, and sucrose content, respectively, and some of the QTLs coincided with soybean domestication-related genomic loci. The major QTL for protein and oil were mapped on Chr. 20 (qPro_20) and suggested negative correlation between oil and protein. In terms of sucrose content, a novel and major QTL were identified on Chr. 8 (qSuc_08) and harbours putative genes involved in sugar transport. In addition, genome-wide association using 91 342 SNPs confirmed the genomic loci derived from QTL mapping. A QTL-based haplotype using whole-genome resequencing of 106 diverse soybean lines identified unique allelic variation in wild soybean that could be utilized to widen the genetic base in cultivated soybean.

Role of lipolysis in postoral and oral fat preferences in mice

Fatty acid receptors in the mouth and gut are implicated in the appetite for fat-rich foods. The role of lipolysis in oral- and postoral-based fat preferences of C57BL/6J mice was investigated by inhibiting lipase enzymes with orlistat. Experiment 1 showed that postoral lipolysis is required: mice learned to prefer (by 70%) a flavored solution paired with intragastric infusions of 5% soybean oil but not a flavor paired with soybean oil + orlistat (4 mg/g fat) infusions. Experiments 2-4 tested the oral attraction to oil in mice given brief choice tests that minimize postoral effects. In experiment 2, the same low orlistat dose did not reduce the strong (83-94%) preference for 2.5 or 5% soybean oil relative to fat-free vehicle in 3-min tests. Mice in experiment 3 given choice tests between two fat emulsions (2% triolein, corn oil, or soybean oil) with or without orlistat at a high dose (250 mg/g fat) preferred triolein (72%) and soybean oil (67%) without orlistat to the oil with orlistat but were indifferent to corn oil with and without orlistat. In experiment 4, mice preferred 2% triolein (62%) or soybean oil (89%) to vehicle when both choices contained orlistat (250 mg/g fat). Fatty acid receptors are thus essential for postoral but not oral-based preferences. Both triglyceride and fatty acid taste receptors may mediate oral fat preferences.

Effect of Emulsifier Concentration and Physical State on the In Vitro Digestion Behavior of Oil-in-Water Emulsions

The influence of emulsifier physical state and concentration on the in vitro digestion of oil-in-water (O/W) emulsions was investigated. Two citrated monoacylglycerols, glyceryl stearate citrate (GSC, bulk mp of 55-65 °C) and glyceryl oleate citrate (GOC, bulk mp of 0-10 °C), were used at 0.5 or 5 wt % of the emulsions to generate 20 wt % soybean oil O/W emulsions. Oil droplet lipolysis was slower in emulsions with 0.5 wt % emulsifier versus in those with 5 wt % emulsifier, resulting from the reduced surface-to-volume ratio in emulsions at 0.5 wt % emulsifier and the increased concentration of hydrolyzable groups at 5 wt % emulsifier. When excluding gastric digestion, all emulsions were similarly digested, confirming that emulsion intestinal digestion was highly dependent on gastric preprocessing. Finally, at a given emulsifier concentration, GSC-based emulsions with an interfacial crystalline shell experienced a decreased rate of intestinal lipid digestion compared with their GOC-based counterparts, confirming that emulsifier physical state played a role in lipid digestion.

Efficient Biotransformation of Phytosterols to Dehydroepiandrosterone by Mycobacterium sp

In this study, a method for the efficient production of dehydroepiandrosterone (DHEA) from phytosterols in a vegetable oil/aqueous two-phase system by Mycobacterium sp. was developed. After the 3-hydroxyl group of phytosterols was protected, they could be converted into DHEA with high yield and productivity by Mycobacterium sp. NRRL B-3683. In a shake flask biotransformation, 15.05 g l^-1 of DHEA and a DHEA yield of 85.39% (mol mol^-1) were attained after 7 days with an initial substrate concentration of 25 g l^-1. When biotransformation was carried out in a 30-l stirred bioreactor with 25 g l^-1 substrate, the DHEA concentration and yield was 16.33 g l^-1 and 92.65% (mol mol^-1) after 7 days, respectively. The results of this study suggest that inexpensive phytosterols could be utilized for the efficient production of DHEA.

Biorefining of platinum group metals from model waste solutions into catalytically active bimetallic nanoparticles

Bacteria can fabricate platinum group metal (PGM) catalysts cheaply, a key consideration of industrial processes and waste decontaminations. Biorecovery of PGMs from wastes is promising but PGM leachates made from metallic scraps are acidic. A two-step biosynthesis 'pre-seeds' metallic deposits onto bacterial cells benignly; chemical reduction of subsequent metal from acidic solution via the seeds makes bioscaffolded nanoparticles (NPs). Cells of Escherichia coli were seeded using Pd(II) or Pt(IV) and exposed to a mixed Pd(II)/Pt(IV) model solution under H2 to make bimetallic catalyst. Its catalytic activity was assessed in the reduction of Cr(VI), with 2 wt% or 5 wt% preloading of Pd giving the best catalytic activity, while 1 wt% seeds gave a poorer catalyst. Use of Pt seeds gave less effective catalyst in the final bimetallic catalyst, attributed to fewer and larger initial seeds as shown by electron microscopy, which also showed a different pattern of Pd and Pt deposition. Bimetallic catalyst (using cells preloaded with 2 wt% Pd) was used in the hydrogenation of soybean oil which was enhanced by ~fourfold using the bimetallic catalyst made from a model waste solution as compared to 2 wt% Pd preloaded cells alone, with a similar selectivity to cis C18:1 product as found using a Pd-Al2 O3 commercial catalyst.

Benefits of Fish Oil Consumption over Other Sources of Lipids on Metabolic Parameters in Obese Rats

This study evaluated the effect of the consumption of different levels and sources of lipids on metabolic parameters of Wistar rats. Animals were fed with high-fat diet (HFD) containing 20% of lard for 12 weeks to cause metabolic obesity. Subsequently, the animals were divided into six groups and were fed diets with lipid concentrations of 5% or 20% of lard (LD), soybean oil (SO) or fish oil (FO), for 4 weeks. Data were submitted to analysis of variance (two-way) followed by Tukey post hoc test (p < 0.05). The groups that consumed FO showed less weight gain and lower serum levels of triacylglycerol (TAG), total cholesterol and fractions, aspartate aminotransferase (AST) activity, atherogenic index, less amount of fat in the carcass, decreased Lee index and lower total leukocyte counting (p < 0.05). These same parameters were higher in LD treatment (p < 0.05). In the concentration of 20%, carcass fat content, blood glucose levels, as well as alanine aminotransferase (ALT) and gamma glutamyl transferase (GGT) decreased in FO groups (p < 0.05). The SO group had intermediate results regarding the other two treatments (FO and LD). We concluded that fish oil intake was able to modulate positively the metabolic changes resulting from HFD.

Growth performance, fatty-acid composition, lipid deposition and hepatic-lipid metabolism-related gene expression in juvenile pond loach Misgurnus anguillicaudatus fed diets with different dietary soybean oil levels

A 10 week feeding trial was conducted to evaluate the effects of different dietary soybean oil (SO) levels on growth performance, fatty-acid composition and lipid deposition in viscera, histology and histochemistry of liver, intestine and hepatic-lipid metabolism-related gene expressions in pond loach Misgurnus anguillicaudatus juveniles. Misgurnus anguillicaudatus (mean ± s.d. mass 0·40 ± 0·01 g) were fed five experimental diets containing SO at different concentrations: 0, 20, 32, 56 and 100% SO and a diet containing 100% fish oil (100% FO). The mass gains and specific growth rates of M. anguillicaudatus fed 20% SO and 100% FO diets were significantly higher than those of the other groups (P < 0·05). The lipid content of viscera and the amount of cytoplasmic vacuolation in the liver increased with incremental dietary SO level. Meanwhile, increasing dietary SO levels up-regulated the messenger (m)RNA levels of lipogenic genes (such as Δ6fad, scd, pparγ, fas and srebp-1) and down-regulated the mRNA levels of the lipolytic genes (such as pparα, cpt1, atgl and hsl) in the liver. The percentage of 20:4n-6 significantly (P < 0·05) increased with increasing dietary SO level, which might be correlated with the up-regulation of the mRNA level of Δ6fad. The highest levels of dietary SO, however, had a negative effect on growth performance, lipid deposition of viscera and histology and histochemstry of liver and intestine. The increased lipid accumulation induced by incremental dietary SO level probably occurred through different strategies for lipid metabolism as a result of competition between lipolysis and lipogenesis and between export and import of lipids in this species.

Elevation of soybean seed oil content through selection for seed coat shininess

Many leguminous species have adapted their seed coat with a layer of powdery bloom that contains hazardous allergens and makes the seeds less visible, offering duel protection against potential predators 1 . Nevertheless, a shiny seed surface without bloom is desirable for human consumption and health, and is targeted for selection under domestication. Here we show that seed coat bloom in wild soybeans is mainly controlled by Bloom1 (B1), which encodes a transmembrane transporter-like protein for biosynthesis of the bloom in pod endocarp. The transition from the 'bloom' to 'no-bloom' phenotypes is associated with artificial selection of a nucleotide mutation that naturally occurred in the coding region of B1 during soybean domestication. Interestingly, this mutation not only 'shined' the seed surface, but also elevated seed oil content in domesticated soybeans. Such an elevation of oil content in seeds appears to be achieved through b1-modulated upregulation of oil biosynthesis in pods. This study shows pleiotropy as a mechanism underlying the domestication syndrome 2 , and may pave new strategies for development of soybean varieties with increased seed oil content and reduced seed dust.

Heterologous expression and characterization of a new lipase from Pseudomonas fluorescens Pf0-1 and used for biodiesel production

As a kind of important biocatalysts, Pseudomonas lipases are commonly applied in various industrial fields. Pflip1, a new extracellular lipase gene from Pseudomonas. fluorescens Pf0-1, was first cloned and respectively expressed in Escherichia coli BL21(DE3) and Pichia pastoris KM71, the recombinant proteins Pflip1a and Pflip1b were later purified separately. Then Pflip1a was further characterized. The optimum pH of Pflip1a was 8.0 and its optimal temperature was 70 °C. After incubation at 70 °C for 12 h, Pflip1a could retain over 95% of its original activity. It showed the highest activity towards p-nitrophenyl caprylate. Moreover, its activity was profoundly affected by metal ion, ionic surfactants and organic solvents. Furthermore, the two obtained recombinant lipases were immobilized on the magnetic nanoparticles for biodiesel preparation. The GC analysis showed that for the immobilized lipases Pflip1b and Pflip1a, the biodiesel yield within 24 h respectively attained 68.5% and 80.5% at 70 °C. The activities of the two immobilized lipases still remained 70% and 82% after 10 cycles of operations in non-solvent system. These characteristics and transesterification capacity of the recombinant protein indicated its great potential for organic synthesis, especially for biodiesel production.

The Physical State of Emulsified Edible Oil Modulates Its in Vitro Digestion

Emulsified lipid digestion was tailored by manipulating the physical state of dispersed oil droplets in whey protein stabilized oil-in-water (O/W) emulsions, where the oil phase consisted of one of five ratios of soybean oil (SO) and fully hydrogenated soybean oil (FHSO). The evolution in particle size distribution, structural changes during oral, gastric, and intestinal digestion, and free fatty acid release during intestinal digestion were all investigated. Irrespective of the physical state and structure of the dispersed oil/fat, all emulsions were stable against droplet size increases during oral digestion. During gastric digestion, the 50:50 SO:FHSO emulsion was more stable against physical breakdown than any other emulsion. All emulsions underwent flocculation and coalescence or partial coalescence upon intestinal digestion, with the SO emulsion being hydrolyzed the most rapidly. The melting point of all emulsions containing FHSO was above 37 °C, with the presence of solid fat within the dispersed oil droplets greatly limiting lipolysis. Fat crystal polymorph and nanoplatelet size did not play an important role in the rate and extent of lipid digestion. Free fatty acid release modeled by the Weibull distribution function showed that the rate of lipid digestion (κ) decreased with increasing solid fat content, and followed an exponential relationship (R² = 0.95). Overall, lipid digestion was heavily altered by the physical state of the dispersed oil phase within O/W emulsions.

Intravenous administration of oxytocin in rats acutely decreases deprivation-induced chow intake, but it fails to affect consumption of palatable solutions

Despite its limited ability to cross the blood-brain barrier, peripherally administered oxytocin (OT) acutely decreases food intake, most likely via the brainstem and hypothalamic mechanisms. Studies performed to date have focused mainly on the effects of subcutaneous or intraperitoneal OT on the consumption of only solid calorie-dense diets (either standard or high-fat), whereas it is unknown whether, similarly to central OT, peripherally administered peptide reduces intake of calorie-dilute and non-caloric palatable solutions. In this project, we established that 0.1μg/kg intravenous (IV) OT is the lowest anorexigenic dose, decreasing deprivation-induced standard chow intake by ca. 40% in rats and its effect does not stem from aversion. We then used this dose in paradigms in which effects of centrally acting OT ligands on consumption of palatable solutions had been previously reported. We found that IV OT did not change episodic intake of individually presented palatable solutions containing 10% sucrose, 0.1% saccharin, combined 10% sucrose-0.1% saccharin or 4.1%. Intralipid and it failed to affect daily scheduled consumption of a sucrose solution in non-deprived rats. In a two-bottle choice test, IV OT did not shift animals' preference from sucrose to Intralipid. Finally, OT injected IV prior to the simultaneous presentation chow and a sucrose solution in food-deprived rats significantly decreased chow intake, whereas sugar water consumption remained unchanged. We conclude that IV OT reduces deprivation-induced chow intake without causing aversion, but the dose effective in decreasing energy-driven consumption of high-calorie food fails to affect consumption of palatable calorie-dilute solutions.

Effect of Sea-Buckthorn (Hippophaë rhamnoides L.) Pulp Oil Consumption on Fatty Acids and Vitamin A and E Accumulation in Adipose Tissue and Liver of Rats

An in vivo experiment was conducted to determine the effect of sea-buckthorn pulp oil feeding on the fatty acid composition of liver and adipose tissue of Wistar rats and the liver accumulation of retinol, its esters and α-tocopherol. For a period of 28 days, rats were given a modified casein diet (AIN-93) in which sea-buckthorn pulp oil, soybean oil and pork lard were used as sources of fat. Compared to the other fat sources, sea-buckthorn pulp oil was the most abundant in C16 fatty acids, carotenoids (mainly β-carotene) and tocopherols (mainly α-tocopherol). Its consumption was reflected in an increased share of palmitoleic acid in adipose tissue and the liver and an increased level of retinol in liver tissues (this was not observed for its esters). Although the type of fat did not have a significant effect on the average content of α-tocopherol in the liver, the variation of saturation of this tissue with α-tocopherol was the lowest when rats were fed a diet containing sea-buckthorn oil. This experiment indicates the possibility of affecting adipose tissue and liver by a diet.

Effects of tallow, choice white grease, palm oil, corn oil, or soybean oil on apparent total tract digestibility of minerals in diets fed to growing pigs

An experiment was conducted to determine the effect of supplementing diets fed to growing pigs with fat sources differing in their composition of fatty acids on the apparent total tract digestibility (ATTD) of minerals. A diet based on corn, potato protein isolate, and 7% sucrose was formulated. Five additional diets that were similar to the previous diet with the exception that sucrose was replaced by 7% tallow, choice white grease, palm oil, corn oil, or soybean oil were also formulated. Diets were formulated to contain 0.70% Ca and 0.33% standardized total tract digestible P. Growing barrows ( = 60; 15.99 ± 1.48 kg initial BW) were allotted to a randomized complete block design with 2 blocks of 30 pigs, 6 dietary treatments, and 10 replicate pigs per treatment. Experimental diets were provided for 12 d with the initial 5 d being the adaptation period. Total feces were collected for a 5-d collection period using the marker-to-marker approach, and the ATTD of minerals, ether extract, and acid hydrolyzed ether extract was calculated for all diets. Digestibility of DM was greater ( < 0.05) in the diet containing soybean oil compared with the diet containing choice white grease or the basal diet, with all other diets being intermediate. The ATTD of Ca, S, and P was greater ( < 0.05) for pigs fed diets containing soybean oil, corn oil, palm oil, or tallow than for pigs fed the basal diet or the diet containing choice white grease. The ATTD of Mg, Zn, Mn, Na, and K were not different among dietary treatments. The ATTD of ether extract was greater ( < 0.05) in diets containing palm oil, corn oil, or soybean oil compared with the diet containing choice white grease, and the ATTD of acid hydrolyzed ether extract in the diet containing soybean oil was also greater ( < 0.05) than in the diet containing choice white grease. In conclusion, supplementation of a basal diet with tallow, palm oil, corn oil, or soybean oil may increase the ATTD of some macrominerals, but that appears not to be the case if choice white grease is used. There was no evidence of negative effects of the fat sources used in this experiment on the ATTD of any minerals.

Digestibility of energy and lipids and oxidative stress in nursery pigs fed commercially available lipids

An experiment was conducted to evaluate the impact of lipid source on GE and ether extract (EE) digestibility, oxidative stress, and gut integrity in nursery pigs fed diets containing 10% soybean oil (SO), choice white grease (CWG), palm oil (PO), distillers' corn oil with approximately 5% FFA (DCO-1), or distillers' corn oil with approximately 10% FFA (DCO-2). Fifty-four barrows weaned at 28 d of age were fed a common starter diet for 7 d, group fed their respective experimental diets for an additional 7 d, and then moved to metabolism crates and individually fed their respective diets for another 10 d. Following this period, a 4-d total fecal and urine collection period was used to determine apparent total tract digestibility (ATTD) of GE and EE and to determine the DE and ME content of each lipid source (11.03 ± 0.51 kg final BW). Following the last day of fecal and urine collection, pigs were given an oral dose of lactulose and mannitol and fed their respective experimental diets with urine collected for the following 12 h. A subsequent urine collection occurred for 5 h to determine thiobarbituric acid reactive substances (TBARS) and isoprostane (IsoP) concentrations. Following this urine collection, serum was obtained and analyzed for TBARS and endotoxin concentrations. Soybean oil had the greatest ( < 0.05) DE (9,388 kcal/kg) content compared with DCO-1, DCO-2, CWG, and PO (8,001, 8,052, 8,531, and 8,293 kcal/kg lipid, respectively). Energy digestibility was greatest for SO compared with the other lipid sources ( < 0.05). The ATTD of EE averaged 85.0% and varied slightly (84.4 to 85.6%) among treatments. Differences in ME content among lipids were similar to those reported for DE, with ME values for DCO-1, DCO-2, CWG, PO, and SO being 7,921, 7,955, 8,535, 8,350, and 9,408 kcal/kg lipid, respectively. Metabolizable energy as a percentage of DE did not differ among lipid sources. Pigs fed lipid diets had greater ( < 0.05) serum TBARS compared with pigs fed the control diet, but no differences were observed in urinary TBARS excretion among the lipid treatments. Urinary IsoP excretion differed among treatments ( < 0.01) but was highly variable (34.0 to 104.6 pg). However, no differences were observed among treatments for the urinary lactulose:mannitol ratio and serum endotoxin. These results indicate that DE and ME content of SO are greater than that of other lipid sources evaluated, but feeding these lipids has no effect on gut integrity while producing variable effects on oxidative stress.

An Induced Chromosomal Translocation in Soybean Disrupts a KASI Ortholog and Is Associated with a High-Sucrose and Low-Oil Seed Phenotype

Mutagenesis is a useful tool in many crop species to induce heritable genetic variability for trait improvement and gene discovery. In this study, forward screening of a soybean fast neutron (FN) mutant population identified an individual that produced seed with nearly twice the amount of sucrose (8.1% on dry matter basis) and less than half the amount of oil (8.5% on dry matter basis) as compared to wild type. Bulked segregant analysis (BSA), comparative genomic hybridization, and genome resequencing were used to associate the seed composition phenotype with a reciprocal translocation between chromosomes 8 and 13. In a backcross population, the translocation perfectly cosegregated with the seed composition phenotype and exhibited non-Mendelian segregation patterns. We hypothesize that the translocation is responsible for the altered seed composition by disrupting a β-ketoacyl-[acyl carrier protein] synthase 1 (KASI) ortholog. KASI is a core fatty acid synthesis enzyme that is involved in the conversion of sucrose into oil in developing seeds. This finding may lead to new research directions for developing soybean cultivars with modified carbohydrate and oil seed composition.

Comparison of macauba and soybean oils as substrates for the enzymatic biodiesel production in ultrasound-assisted system

The objective of this study is to evaluate the batch enzymatic production of biodiesel in solvent-free system under ultrasound using as substrates ethanol, soybean oil and macauba fruit oil. For this purpose, a Plackett & Burman experimental design was carried out for soybean oil while a 2^4-1 design was conducted for macauba oil in order to maximize the biodiesel conversion for each system. Good conversions to fatty acid ethyl esters (FAEE), 88% for soybean oil and 75.2% for macauba oil, was obtained thus demonstrating the potential use of ultrasound for this reaction system.

Genotyping-by-Sequencing-Based Investigation of the Genetic Architecture Responsible for a ∼Sevenfold Increase in Soybean Seed Stearic Acid

Soybean oil is highly unsaturated but oxidatively unstable, rendering it nonideal for food applications. Until recently, the majority of soybean oil underwent partial chemical hydrogenation, which produces trans fats as an unavoidable consequence. Dietary intake of trans fats and most saturated fats are conclusively linked to negative impacts on cholesterol levels and cardiovascular health. Two major soybean oil breeding targets are: (1) to reduce or eliminate the need for chemical hydrogenation, and (2) to replace the functional properties of partially hydrogenated soybean oil. One potential solution is the elevation of seed stearic acid, a saturated fat which has no negative impacts on cardiovascular health, from 3 to 4% in typical cultivars to > 20% of the seed oil. We performed QTL analysis of a population developed by crossing two mutant lines, one with a missense mutation affecting a stearoyl-acyl-carrier protein desaturase gene resulting in ∼11% seed stearic acid crossed to another mutant, A6, which has 24-28% seed stearic acid. Genotyping-by-sequencing (GBS)-based QTL mapping identified 21 minor and major effect QTL for six seed oil related traits and plant height. The inheritance of a large genomic deletion affecting chromosome 14 is the basis for largest effect QTL, resulting in ∼18% seed stearic acid. This deletion contains SACPD-C and another gene(s); loss of both genes boosts seed stearic acid levels to ≥ 18%. Unfortunately, this genomic deletion has been shown in previous studies to be inextricably correlated with reduced seed yield. Our results will help inform and guide ongoing breeding efforts to improve soybean oil oxidative stability.

Direct stacking of sequence-specific nuclease-induced mutations to produce high oleic and low linolenic soybean oil

BACKGROUND

The ability to modulate levels of individual fatty acids within soybean oil has potential to increase shelf-life and frying stability and to improve nutritional characteristics. Commodity soybean oil contains high levels of polyunsaturated linoleic and linolenic acid, which contribute to oxidative instability - a problem that has been addressed through partial hydrogenation. However, partial hydrogenation increases levels of trans-fatty acids, which have been associated with cardiovascular disease. Previously, we generated soybean lines with knockout mutations within fatty acid desaturase 2-1A (FAD2-1A) and FAD2-1B genes, resulting in oil with increased levels of monounsaturated oleic acid (18:1) and decreased levels of linoleic (18:2) and linolenic acid (18:3). Here, we stack mutations within FAD2-1A and FAD2-1B with mutations in fatty acid desaturase 3A (FAD3A) to further decrease levels of linolenic acid. Mutations were introduced into FAD3A by directly delivering TALENs into fad2-1a fad2-1b soybean plants.

RESULTS

Oil from fad2-1a fad2-1b fad3a plants had significantly lower levels of linolenic acid (2.5 %), as compared to fad2-1a fad2-1b plants (4.7 %). Furthermore, oil had significantly lower levels of linoleic acid (2.7 % compared to 5.1 %) and significantly higher levels of oleic acid (82.2 % compared to 77.5 %). Transgene-free fad2-1a fad2-1b fad3a soybean lines were identified.

CONCLUSIONS

The methods presented here provide an efficient means for using sequence-specific nucleases to stack quality traits in soybean. The resulting product comprised oleic acid levels above 80 % and linoleic and linolenic acid levels below 3 %.