Incorporation of germinated lupin into corn-based extrudates: Focus on starch digestibility, matrix structure and physicochemical properties.

The research aimed to assess the effects of incorporating germinated Lupinus angustifolius flour into corn extrudates for different periods (3, 5, and 7 days), focusing on starch digestibility, morphological structure, thermal, and pasting properties. Extrudate with germinated lupinus flour for 7 days (EG7) significantly increased the content of slowly digestible starch up to 10.56% (p < 0.05). Crystallinity increased up to 20% in extrudates with germinated flour compared to extrudates with ungerminated flour (EUG), observing changes at the molecular level by FTIR that impact the thermal and pasting properties. X-ray diffraction revealed angles of 2θ = 11.31, 16.60, 19.91, and 33.04 as a result of the germination and extrusion processes. Microstructural analysis indicated starch-protein interactions influencing changes in calorimetry, viscosity, X-ray diffraction, and digestibility. PCA allowed establishing that the addition of germinated flours significantly affected the properties and microstructural characteristics of extruded products, potentially affecting digestibility and nutritional quality.

Time maters: Exploring the dynamics of bioactive compounds content, bioaccessibility and antioxidant activity during Lupinus angustifolius germination.

Germination is a process that enhances the content of health-promoting secondary metabolites. However, the bioaccessibility of these compounds depends on their stability and solubility throughout the gastrointestinal tract. The study aimed to explore how germination time influences the content and bioaccessibility of γ-aminobutyric acid and polyphenols and antioxidant capacity of lupin (Lupinus angustifolius L.) sprouts during simulated gastrointestinal digestion. Gamma-aminobutyric acid showed a decrease following gastrointestinal digestion (GID) whereas phenolic acids and flavonoids exhibited bioaccessibilities of up to 82.56 and 114.20%, respectively. Although the digestion process affected the profile of phenolic acids and flavonoids, certain isoflavonoids identified in 7-day sprouts (G7) showed resistance to GID. Germination not only favored antioxidant activity but also resulted in germinated samples exhibiting greater antioxidant properties than ungerminated counter parts after GID. Intestinal digests from G7 did not show cytotoxicity in RAW 264.7 macrophages, and notably, they showed an outstanding ability to inhibit the production of reactive oxygen species. This suggests potential benefit in mitigating oxidative stress. These findings contribute to understand the dynamic interplay between bioprocessing and digestion in modulating the bioaccessibility of bioactive compounds in lupin, thereby impacting health.

Morphological and physiological properties of lupine nodule bacteria (Bradyrhizobium lupini) when grown on a typical urban soil.

In the conducted studies, the moorphological and physiological properties of nodule bacteria of lupine were studied. Lupine plants were grown under the conditions of a microfield experiment on a typical medium loamy urban soil. In the study, a pure culture of Bradyrhizobium lupini was isolated. Then, the morphological properties of nodule bacteria cells and the chemical composition of cell membranes of nodule bacteria were determined. The acid resistance and physiological properties of lupine nodule bacteria were also determined, as well as the ratio of Bradyrhizobium lupini to antibiotics. All studies were carried out according to generally accepted methods. The results of the research showed that during the cultivation of lupine on a typical urban soil, nodule bacteria Bradyrhizobium lupini were isolated, which can be characterized as gram-negative, non-spore-forming rods that do not exhibit amylolytic activity. It was revealed that the rhizobia of nodule bacteria are not acid-resistant. Nodule bacteria turned out to be the least resistant to polymyxin, then to levomycetin, and Bradyrhizobium lupini showed the greatest resistance to tetracycline.

Chemical Characterization of White Lupin (Lupinus albus) Flour Treated by Extrusion Cooking and Aqueous Debittering Processes.

Lupin is a very nutritious legume with high levels of protein and fiber, but it also contains quinolizidine alkaloids which, depending on the species, can accumulate to toxic levels. The objective of this work was to evaluate the white lupin chemical composition, due to the effects of different processes (aqueous debittering, extrusion cooking, and reactive extrusion), aiming at reducing total alkaloids, preserving fibers, and increasing in vitro protein digestibility. Regarding raw material, the aqueous process reduced significantly total alkaloids (-93.87%), increased dietary fiber (+22.03%), and increased protein digestibility (+6.73%), whereas the extrusion processes were inefficient to reduce alkaloids (< -3.70%) and reduced the dietary fiber content, the reduction being more severe during reactive extrusion (-75.36%). Protein digestibility was improved by extrusion cooking (+3.07%), while the reactive extrusion reduced digestibility (-12.50%). Electrophoresis and quantification of soluble proteins and aromatic amino acids confirmed the high digestibility index, staying only the γ-conglutin fraction in the digested samples evaluated by SDS-PAGE. The aqueous process proved to be the best option, as it reduces the alkaloid content to safe levels and improves the protein digestion of white lupin flour.

High prevalence of lupin allergy among patients with peanut allergy: Identification of γ-conglutin as major allergen.

BACKGROUND: Lupin is a protein-rich legume with a growing presence in the food market worldwide. With increased consumption, lupin allergy (LA) reports are also rising. Uncertainties exist on the cross-reactivity between peanut and lupin, the allergenic potential of different lupin species, and sensitization patterns among different populations. OBJECTIVE: To evaluate the molecular basis of LA and to determine lupin allergens from 3 different species that may be involved in peanut allergy (PA) cross-reactivity. METHODS: A total of 43 subjects with PA, those with LA, or controls without food allergy were evaluated with skin prick tests (SPTs) and specific IgEs (sIgEs). Lupin-sensitized subjects were offered a lupin oral food challenge (OFC). Immunoblots and enzyme-linked immunosorbent assays were performed on sera from lupin-sensitized subjects. RESULTS: In this study, 44% of the PA subjects were confirmed to have LA by OFC. Anaphylaxis was the most frequent manifestation after lupin consumption, with a minimal eliciting dosage of 1 g lupin flour. There was no difference in lupin sIgE or SPT wheal size between lupin-sensitized and confirmed LA subjects or in the severity of symptoms among confirmed LA subjects. Sera from lupin-sensitized subjects uniformly reacted to all 3 different lupin species. Immunoblotting and enzyme-linked immunosorbent assays revealed immunoglobulin E binding to α- and γ-conglutin in all analyzed sera, whereas α- and ß-conglutin recognition was variable. CONCLUSION: Our findings reveal a high prevalence of LA among PA subjects, emphasizing lupin must be labeled as an allergen in foods. Owing to high variability in lupin-sIgE and lupin-SPT results, LA diagnosis may require OFC. In our population, γ-conglutin is the major allergen of lupin.

Effects of Lupin Kernel (Lupinus angustifolius) and Faba Bean (Vicia faba) on Growth Performance and Hepatic Fatty Acid Profiles in Broiler Chicks

This study was conducted to evaluate the effect of feeding lupin kernel and faba bean as an alternative to soybean meal on the growth performance, blood profiles, relative organ weight, and hepatic fatty acid composition of broiler chicks. A total of 525, 1-day-old Ross 308 male chicks were randomly assigned into five groups with seven replicates. The treatments consisted of five experimental diets; corn-soybean meal without lupin or faba bean (as control), diets with lupin 5% or 10%, and diets with faba bean 5% or 10%. The body weight (BW) and average daily gain (ADG) were not significantly different among the groups during starter period. However, BW and ADG of chicks fed diets with 10% lupin and faba bean were significantly higher than those of 5% lupin and faba bean during grower period (p<0.01). The feed conversion ratio was significantly lower in the group fed diets with 10% lupin and faba bean than the control during total rearing periods (p<0.001). There were no significant differences in blood profiles among the groups. As for the hepatic fatty acid composition, the levels of total polyunsaturated fatty acids and total ω6 in chicks fed lupin and faba bean were significantly higher than the control. It was suggested that dietary lupin and faba bean could enhance the incorporation of the beneficial fatty acids into liver fraction. In conclusion, supplementation of lupin and faba bean up to 10% can be used as an alternative to soybean meal in broiler diets.(AU)

Modification of the Nutritional Quality and Oxidative Stability of Lupin (Lupinus mutabilis Sweet) and Sacha Inchi (Plukenetia volubilis L.) Oil Blends.

Andean lupin (Lupinus mutabilis) oil is rich in monounsaturated (54.2%) and polyunsaturated (28.5%) fatty acids but has a ω-3:ω-6 ratio (1:9.2) above the recommended values for human health. Sacha inchi (Plukenetia volubilis) oil presents a high polyunsaturated fatty acid content (linolenic 47.2% and linoleic 34.7%), along a ω-3:ω-6 ratio (1:0.74) good for human consumption. The objective of this research was to study the physico-chemical properties and oxidative stability of tarwi and sacha inchi oil blends (1:4, 1:3, 1:1, 3:1 and 4:1 w:w) with suitable ω-3:ω-6 ratios. All blends showed ω-3:ω-6 ratios between 1:0.8 and 1:1.9, acceptable from a nutritional point of view, and high total tocopherols' content (1834-688 mg/kg), thanks to sacha inchi. The oxidative stability index (OSI) of the mixtures by the Rancimat method at 120 °C ranged from 0.46 to 8.80 h. The shelf-life of 1:1 tarwi/sacha inchi oil blend was 1.26 years; its entropy (-17.43 J/mol), enthalpy (107.04 kJ/mol), activation energy (110.24 kJ/mol) and Gibbs energy (113.76 kJ/mol) suggest low oxidation reaction rates and good stability. Hence, balanced blends of tarwi/sacha inchi oils can achieve optimal nutritional properties and enhanced shelf-life.

Yield and quality of Dega white lupine grain (Lupinus Albus) and yubileynaya 80 spring wheat (Triticum Aestivum L.) depending on the application method of sodium selenite.

In 2017-2019, we conducted the field and vegetation experiments at the field station of Russian State Agrarian University, Moscow Timiryazev Agricultural Academy to study the effect of sodium selenite on the yield and grain quality indicators of white lupine, Dega variety, and spring wheat, Yubileynaya-80 variety. The best way found to use selenium is to spray vegetative plants with 0.01% aqueous sodium selenite solution. The studies have shown an increase in grain yield by 15-17%, crude protein content by 9-15% and crude fat content by 5-7% when treated with sodium selenite. The obtained grain yield of white lupine has a higher feed and nutritional value and is suitable for feeding animals and preparing various types of feed and feed additives. The optimal way to use selenium is spraying vegetative plants before shooting. Treatment with sodium selenite contributes to an increase in wheat yield by 1.5 times. We have established the positive effect of sodium selenite on the quality indicators of wheat grain. An increase in the content of raw gluten and glassiness of grain has been noted, which determines high bread-making qualities.

The micronutrient content in underutilized crops: the Lupinus mutabilis sweet case.

Adequate intake of micronutrients is necessary to reduce widespread health issues linked to low intake of iron (Fe), zinc (Zn), boron (B), copper (Cu), and manganese (Mn). Because more than two billion people suffer from micronutrient deficiency globally, to address this problem, highly-nutritious ancestral Peruvian crops like tarwi can be an important component of food security. Thus, our work explores the tarwi micronutrient variability to select biofortified genotypes without affecting seed size and weight. Tarwi is a biofortified food because of its seeds' Fe, Zn, and B content. Furthermore, Boron showed a positive correlation between seed size and weight. At the same time, copper showed a negative correlation. Finally, six accessions (P14, P16, P21, T05, T08, and T25) that are biofortified for Fe, Zn, and B with excellent seed size and weight and with adequate levels of Cu and Mn; adding value to Peruvian biodiversity at a low cost is a starting point for a breeding program to prevent micronutrient disorders.

Composition and Antifungal Activity of the Alkaloidal Fraction of Lupinus mirabilis Leaves: A Biochemometrics-Based Exploration.

Lupinus plants are well-recognized due to their significant alkaloid content, which has made them the subject of several studies. However, the lack of chemical and biological information on the Colombian Lupinus species remains a fact. Therefore, the alkaloidal fractions from the leaves of L. mirabilis obtained by conventional solvent and ultrasound-assisted extraction (CSE and UAE, respectively) at different time frames were analyzed. Sparteine (2) was the main component in all cases; however, its relative abundance showed large variability, ranging from 64.7% to 80.6%. Minor constituents were also affected by the extraction conditions. In general, prolonged times gave a higher proportion of alkaloids under CSE, while only a slight decrease was observed under UAE. Both the method and extraction time appeared to equally affect the ratios of particular alkaloids, leading to variations in their effect on the mycelial growth of Fusarium oxysporum. Holistic analysis through multiple-covariate statistical methods as an approach to integrating chemical and bioactivity datasets allowed inferring the compounds most likely responsible for the changes in mycelial growth inhibition. 13α-Hydroxylupanine (12) might represent a promising compound to be included in further studies against this phytopathogen.

Quinolizidine-Based Variations and Antifungal Activity of Eight Lupinus Species Grown under Greenhouse Conditions.

Fusarium oxysporum is an aggressive phytopathogen that affects various plant species, resulting in extensive local and global economic losses. Therefore, the search for competent alternatives is a constant pursuit. Quinolizidine alkaloids (QA) are naturally occurring compounds with diverse biological activities. The structural diversity of quinolizidines is mainly contributed by species of the family Fabaceae, particularly the genus Lupinus. This quinolizidine-based chemo diversity can be explored to find antifungals and even mixtures to address concomitant effects on F. oxysporum. Thus, the antifungal activity of quinolizidine-rich extracts (QREs) from the leaves of eight greenhouse-propagated Lupinus species was evaluated to outline promising QA mixtures against F. oxysporum. Thirteen main compounds were identified and quantified using an external standard. Quantitative analysis revealed different contents per quinolizidine depending on the Lupinus plant, ranging from 0.003 to 32.8 mg/g fresh leaves. Bioautography showed that all extracts were active at the maximum concentration (5 µg/µL). They also exhibited >50% mycelium growth inhibition. All QREs were fungistatic except for the fungicidal QRE of L. polyphyllus Lindl. Angustifoline, matrine, 13α-hydroxylupanine, and 17-oxolupanine were ranked to act jointly against the phytopathogen. Our findings constitute reference information to better understand the antifungal activity of naturally afforded QA mixtures from these globally important plants.

Extraction, purification by cation exchange supermacroporous cryogel and physico-chemical characterization of γ-conglutin from lupin seeds (Lupinus albus L.).

This study focused on the extraction, purification, and physicochemical characterization of γ-conglutin, a protein present in lupin seeds with properties of reducing blood glucose levels. Total protein was extracted with an alkaline-saline solvent, followed by isoelectric precipitation. Chromatographic purification of the precipitated fraction was performed using a cation exchange supermacroporous cryogel column. Electrophoresis of the eluted fraction from chromatography presented a single band of ∼48 kDa under non-reducing conditions (two bands of ∼30 and ∼17 kDa, under reducing conditions) confirming the success of the purification protocol. Liquid chromatography-tandem mass spectrometry analysis confirmed the identity of the protein as γ-conglutin. The purified γ-conglutin had an isoelectric point of 7.51, ß-sheets prevailing as a secondary structure, and denaturation temperature close to 68°C. The outcome of this work showed that γ-conglutin was obtained with a high degree of purity. The proposed purification protocol is simple and can be easily scaled up.

Yield and quality of Dega white lupine grain (Lupinus Albus) and yubileynaya 80 spring wheat (Triticum Aestivum L. ) depending on the application method of sodium selenite / Rendimento e qualidade do grão de tremoço branco Dega (Lupinus albus) e trigo de primavera Yubileynaya 80 (Triticum aestivum L. ) em função do método de aplicação do selenito de sódio

In 2017-2019, we conducted the field and vegetation experiments at the field station of Russian State Agrarian University, Moscow Timiryazev Agricultural Academy to study the effect of sodium selenite on the yield and grain quality indicators of white lupine, Dega variety, and spring wheat, Yubileynaya-80 variety. The best way found to use selenium is to spray vegetative plants with 0.01% aqueous sodium selenite solution. The studies have shown an increase in grain yield by 15-17%, crude protein content by 9-15% and crude fat content by 5-7% when treated with sodium selenite. The obtained grain yield of white lupine has a higher feed and nutritional value and is suitable for feeding animals and preparing various types of feed and feed additives. The optimal way to use selenium is spraying vegetative plants before shooting. Treatment with sodium selenite contributes to an increase in wheat yield by 1.5 times. We have established the positive effect of sodium selenite on the quality indicators of wheat grain. An increase in the content of raw gluten and glassiness of grain has been noted, which determines high bread-making qualities.

Em 2017-2019, conduzimos os experimentos de campo e vegetação na estação de campo da Universidade Agrária Estatal Russa, Academia Agrícola Timiryazev de Moscou, para estudar o efeito do selenito de sódio nos indicadores de rendimento e qualidade de grãos de tremoço branco, variedade Dega, e trigo de primavera, variedade Yubileynaya-80. A melhor maneira encontrada para usar o selênio é pulverizar as plantas vegetativas com solução aquosa de selenito de sódio a 0,01%. Os estudos mostraram um aumento no rendimento de grãos em 15-17%, teor de proteína bruta em 9-15% e teor de gordura bruta em 5-7% quando tratados com selenito de sódio. O rendimento de grãos obtido de tremoço branco tem maior valor alimentar e nutricional e é adequado para alimentação de animais e preparação de vários tipos de rações e aditivos alimentares. A maneira ideal de usar o selênio é pulverizar plantas vegetativas antes de fotografar. O tratamento com selenito de sódio contribui para um aumento no rendimento do trigo em 1,5 vez. Estabelecemos o efeito positivo do selenito de sódio nos indicadores de qualidade do grão de trigo. Observou-se um aumento no teor de glúten cru e vítreo do grão, o que determina altas qualidades de panificação.

Harinas de lupino blanco (Lupinus albus) y andino (L. mutabilis) aptas para consumo: características físico-químicas y funcionales / White lupine (Lupinus albus) and Andean lupine (L. mutabilis) flours suitable for consumption: physico-chemical and functional characteristics

Resumen Introducción: los lupinos son legumbres fuente de nutrientes y fitoquímicos con propiedades beneficiosas para la salud. Sin embargo, presentan alcaloides que deben ser eliminados previos al consumo. El objetivo del estudio fue obtener y caracterizar harinas de lupino blanco y andino, aptas para el consumo. Materiales y método: los granos se desamargaron por método acuoso tradicional que incluyó remojo por 18 horas, cocción por 1 hora y lavado por 5 días. Luego, se secaron en estufa, se molieron y tamizaron. Se determinó alcaloides, proteínas, grasas, fibra dietaria total, sodio, fósforo, color, índice de absorción y solubilidad en agua, polifenoles totales, flavonoides, carotenoides y perfil de fenoles en semillas crudas y harinas tratadas. Resultados: el contenido de alcaloides en las harinas tratadas se encontró entre los límites establecidos para la ingesta segura (<0,07 g/100g). Las proteínas se encontraron entre 25-39 g/100g, grasas entre 12-23 g/100g, fibra dietaria total 35-50 g/100g y cenizas 1,5-3,3 g/100g. El calcio se encontró entre 210-323 mg/100g, fósforo 140-202 mg/100g y sodio 38-44 mg/100g. El color correspondió al amarillo con tendencia al rojo. La harina de lupino andino tratada presentó mayor índice de absorción de agua (7,8 g/g) y solubilidad en agua (78,8%). Los productos tratados presentaron polifenoles (13,4 y 20,8 mg/100g), flavonoides (27,5 y 8,7 mg/100g) y carotenoides (0,3 y 0,9 mg/100g). El perfil de fenoles correspondió a 3 flavonas y 3 isoflavonas en lupino blanco. En el lupino andino, se detectaron 5 flavonas y 3 isoflavonas. Conclusiones. Las harinas tratadas presentan características físico-químicas y funcionales que podrían representar ingredientes alternativos a las tradicionales como trigo y soja, para la formulación de alimentos saludables.

Abstract Introduction: lupins are legumes that are a source of nutrients and phytochemicals with beneficial properties for health. However, they present alkaloids that must be eliminated prior to consumption. The objective of the work was to obtain and characterize White and Andean lupine flours suitable for consumption. Materials and method: the grains were debittered using traditional aqueous method that included soaking for 18 hours, cooking for 1 hour and washing for 5 days. Then, they were dried in an oven, ground and sieved. Alkaloids, proteins, fats, total dietary fiber, sodium, phosphorus, color, absorption rate and water solubility, total polyphenols, flavonoids, carotenoids and phenol profile in raw seeds and treated flours were determined. Results: the alkaloid contents of treated flours were within the limits established for safe intake (less than 0.07 g/100g). Proteins were found between 25-39 g/100g, fats between 12-23 g/100g, total dietary fiber 35-50 g/100g and ash 1.5-3.3 g/100g. Calcium was found between 210-323 mg/100g, phosphorus 140-202 mg/100g and sodium 38-44 mg/100g. The color corresponded to yellow with a tendency to red. The treated Andean lupine flour presented a higher rate of water absorption (7.8 g/g) and solubility in water (78.8%). The treated products presented polyphenols (13.4 and 20.8 mg/100g), flavonoids (27.5 and 8.7 mg/100g) and carotenoids (0.3 and 0.9 mg/100g). The phenolic profile corresponded to 3 flavones and 3 isoflavones in white lupine. In Andean lupine, 5 flavones and 3 isoflavones were detected. Conclusion: the treated flours could represent alternative ingredients to the traditional ones such as wheat and soy for the formulation of healthy foods.

In Vivo Healthy Benefits of Galacto-Oligosaccharides from Lupinus albus (LA-GOS) in Butyrate Production through Intestinal Microbiota.

Animal digestive systems host microorganism ecosystems, including integrated bacteria, viruses, fungi, and others, that produce a variety of compounds from different substrates with healthy properties. Among these substrates, α-galacto-oligosaccharides (GOS) are considered prebiotics that promote the grow of gut microbiota with a metabolic output of Short Chain Fatty Acids (SCFAs). In this regard, we evaluated Lupinus albus GOS (LA-GOS) as a natural prebiotic using different animal models. Therefore, the aim of this work was to evaluate the effect of LA-GOS on the gut microbiota, SCFA production, and intestinal health in healthy and induced dysbiosis conditions (an ulcerative colitis (UC) model). Twenty C57BL/6 mice were randomly allocated in four groups (n = 5/group): untreated and treated non-induced animals, and two groups induced with 2% dextran sulfate sodium to UC with and without LA-GOS administration (2.5 g/kg bw). We found that the UC treated group showed a higher goblet cell number, lower disease activity index, and reduced histopathological damage in comparison to the UC untreated group. In addition, the abundance of positive bacteria to butyryl-CoA transferase in gut microbiota was significantly increased by LA-GOS treatment, in healthy conditions. We measured the SCFA production with significant differences in the butyrate concentration between treated and untreated healthy groups. Finally, the pH level in cecum feces was reduced after LA-GOS treatment. Overall, we point out the in vivo health benefits of LA-GOS administration on the preservation of the intestinal ecosystem and the promotion of SCFA production.

Methyl jasmonate-induced resistance to Delia platura (Diptera: Anthomyiidae) in Lupinus mutabilis.

BACKGROUND: Andean lupin (Lupinus mutabilis Sweet) is an important leguminous crop from South America with a high protein content. In Ecuador, lupin yields are severely affected by the infestation of Delia platura larvae on germinating seeds. The application of elicitor molecules with activity against herbivorous insects to control D. platura infestation constitutes an unexplored and promising alternative for chemical insecticides. In this study, methyl jasmonate (MeJA), hexanoic acid, menadione sodium bisulfite, and DL-ß-aminobutyric acid were evaluated for their ability to induce resistance against D. platura in three commercial lupin cultivars. RESULTS: Only seeds pretreated with MeJA significantly impaired insect performance during choice and no-choice assays. Additionally, fitness indicators such as seed germination and growth were not affected by MeJA treatment. To investigate the molecular mechanisms behind the MeJA-mediated resistance, RT-qPCR assays were performed. First, RT-qPCR reference genes were validated, showing that LmUBC was the most stable reference gene. Next, expression analysis over time revealed that MeJA application up-regulated the activity of the jasmonic acid biosynthetic genes LmLOX2 and LmAOS, together with other jasmonate-related defense genes, such as LmTPS1, LmTPS4, LmPI2, LmMBL, LmL/ODC, LmCSD1, and LmPOD. CONCLUSION: This study indicates that MeJA can be used as an environmentally friendly elicitor molecule to protect Andean lupin from D. platura attack without fitness cost. MeJA application induces plant defense responses to insects in Andean lupin that may be modulated by the onset of terpenoid biosynthesis, proteinase inhibitors, lectins, polyamines, and antioxidative enzymes. © 2021 Society of Chemical Industry.

Culture-independent assessment of the diazotrophic Bradyrhizobium communities in the Pampa and Atlantic Forest Biomes localities in southern Brazil.

The isolation of rhizobial strains from the root and stem nodules remains a commonly used method despite its limitations as it enables the identification of mainly dominant symbiotic groups within rhizobial communities. To overcome these limitations, we used genus-specific nifD primers in a culture-independent assessment of Bradyrhizobium communities inhabiting soils in southern Brazil. The majority of nifD sequences were generated from DNA isolated from tropical-lowland pasture soils, although some soil samples originated from the Campos de Cima da Serra volcanic plateau. In the nifD tree, all the bradyrhizobial sequences comprised 38 clades, including 18 new clades. The sequences generated in this study were resolved into 22 clades and 21 singletons. The nifD bradyrhizobial assemblage contained Azorhizobium and α-proteobacterial methylotrophic genera, suggesting that these genera may have acquired their nif loci from Bradyrhizobium donors. The most common in the lowland pasture soils subclade III.3D branch comprises the isolates of mainly an American origin. On the other hand, subclade III.4, which was earlier detected in Brazil among Bradyrhizobium isolates nodulating native lupins, appears more common in the Campos de Cima da Serra soils. The second-largest group, Clade XXXVIII, has not yet been reported in culture-dependent studies, while another common group called Clade I represents a symbiovar predominating in Australia. The identification of the diverse nifD Clade I haplotypes in the tropical-lowland pastures infested by Australian Acacia spp implies that the introduction of these legumes to southern Brazil has resulted in the dissemination of their bradyrhizobial symbionts.

Chemical Composition, Tocopherol and Carotenoid Content of Seeds from Different Andean Lupin (Lupinus mutabilis) Ecotypes.

Andean lupin (Lupinus mutabilis) seeds are appreciated for their high protein and lipid contents and have potential applications as ingredients in food, cosmetic, and pharmaceutical industries. Nevertheless, the information about the seed composition (especially in lipophilic antioxidants) of ecotypes from distinct cropping areas is currently limited. Thus, the aim of the present research was to assess the morphological characteristics, chemical composition, tocopherol and carotenoid contents of the seeds of 33 Andean lupin ecotypes from different Peruvian regions, along with three L. albus, one L. angustifolius and one L. luteus controls. Significant differences were noted among the Andean ecotypes for all analyzed features. The protein, lipid and ash contents were 32.0-46.9, 13.6-18.6 and 2.7-4.4 g/100 g dry matter (DM), respectively. The seeds were rich in tocopherols (172.1-249.8 mg/kg DM; γ-tocopherol was 98% of total tocols) and low in carotenoids (0.69-2.89 mg/kg DM). Debittering increased the tocopherol content (227.0-378.2 mg/kg DM), probably because of the soluble components loss, although the carotenoid concentration remained unchanged. The Andean lupins had higher protein, lipid and tocopherol contents than L. albus and L. angustifolius; the L. luteus values were within the L. mutabilis range. These results suggest that L. mutabilis harbors nutritional characteristics that are well suited to modern food trends.

Bacillus subtilis CtpxS2-1 induces systemic resistance against anthracnose in Andean lupin by lipopeptide production.

OBJECTIVE: To evaluate the role of the biocontrol agent Bacillus subtilis CtpxS2-1 in inducing lupin systemic resistance against anthracnose caused by Colletotrichum acutatum by lipopeptide production. RESULTS: First, growth inhibition and thin layer chromatography-bioautography analysis confirmed that CtpxS2-1 cultures and their lipopeptide extracts, specifically fengycin, have strong antifungal activity against C. acutatum. Subsequent microscopic examination of these fungal inhibition zones showed mycelial pathogen deformations. PCR amplification of CtpxS2-1 confirmed the presence of genes encoding fengycins E and C, bacillomycin C, iturin A, and surfactins B and C. Based on this evidence, the effect of CtpxS2-1 and its lipopeptides on the induction of the lupin defence- and growth-related genes PR-1, PR-4, SOD-2, PIN-1 and PIN-3 was evaluated by RT-qPCR. In seedlings from roots treated with CtxpS2-1, a significant increase in the expression of these genes was induced. Efficacy assays showed that CtpxS2-1 treatment completely controlled anthracnose incidence (0.0%) compared with the untreated control. Furthermore, root and shoot growth in treated seedlings with CtpxS2-1 significantly increased due to disease control, as did the synthesis of the defence enzymes catalase, peroxidase and superoxide dismutase. CONCLUSION: B. subtilis CtpxS2-1 is a key factor enhancing Andean lupin health by producing lipopeptides that damage C. acutatum cellular structures and inhibit their growth, as well as by inducing the expression of defence-related genes of lupin plants involved in systemic acquired resistance (SAR) against anthracnose.

Purification of Pseudomonas sp. proteases through aqueous biphasic systems as an alternative source to obtain bioactive protein hydrolysates.

Aqueous biphasic systems (ABSs) are an interesting alternative for separating industrial enzymes due to easy scale-up and low operational cost. The proteases of Pseudomonas sp. M211 were purified through ABS platforms formed by polyethylene glycol (PEG) and citrate buffer salt. Two experimental designs 23 + 4 were performed to evaluate the following parameters: molar mass of PEG (MPEG ), concentration of PEG (CPEG ), concentration of citrate buffer (CCit ), and pH. The partition coefficient (K), activity yield (Y), and purification factor (PF) were the responses analyzed. The best purification performance was obtained with the system composed of MPEG  = 10,000 g/mol, CPEG  = 22 wt%, CCit  = 12 wt%, pH = 8.0; the responses obtained were K = 4.9, Y = 84.5%, PF = 15.1, and tie-line length = 52.74%. The purified proteases of Pseudomonas sp. (PPP) were used to obtain hydrolysates of Lupinus mutabilis (Peruvian lupin cultivar) seed protein in comparison with the commercial protease Alcalase® 2.4L. A strong correlation between hydrolysis degree and radical scavenging activity was observed, and the highest antioxidant activity was obtained with Alcalase® (1.40 and 3.47 µmol Trolox equivalent/mg protein, for 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) and oxygen radical absorbance capacity, respectively) compared with PPP (0.55 and 1.03 µmol Trolox/mg protein). Nevertheless, the IC50 values were lower than those often observed for antioxidant hydrolysates from plant proteins. PEG/citrate buffer system is valuable to purify Pseudomonas proteases from the fermented broth, and the purified protease could be promising to produce antioxidant protein hydrolysates.