Nanoremediation and Antioxidant Potential of Biogenic Silver Nanoparticles Synthesized Using Leucena's Leaves, Stem, and Fruits.

Synthetic dyes are persistent organic environmental pollutants that can cause extensive damage to living beings and to the ecosystem as a whole. Cost-effective, sustainable, and efficient strategies to deal with this type of pollution are necessary as it commonly resists conventional water treatment methods. Silver nanoparticles (AgNPs) synthesized using the aqueous extract from the leaves, stem, and fruits of Leucaena leucocephala (Leucena) were produced and characterized through UV-vis, TEM, EDS, SDL, XPS, XRD, and zeta potential, and they proved to be able to promote adsorption to remediate methylene blue and tartrazine pollution in water. The nanoremediation was performed and did not require direct exposure to sunlight or any special lamp or a specific reduction agent. The AgNPs produced using the extract from the leaves exhibited the best performance in nanoremediation and also presented antioxidant activity that surpassed the one from butylated hydroxytoluene (BHT). Consequently, it is an interesting nanotool to use in dye nanoremediation and/or as an antioxidant nanostructure.

Cactus species and tree forage hay in the diet of dairy goats.

The purpose of this study was to evaluate the influence of the association of Opuntia stricta (OS) or Nopalea cochenillifera (NC) with Moringa hay (MY) or Leucaena hay (LY) on nutrient intake, ingestive behavior, serum biochemistry, and milk production and composition of dairy goat. Eight multiparous Saanen goats were used, with an average of 68 ± 8 days in milk and 48.5 ± 6 kg of initial weight, fed with the following treatment diets: OS + MY; OS + LY; NC + MY, and NC + LY. The treatments were distributed in a double Latin square, in a 2 × 2 factorial scheme (two varieties of cactus and two of hay). Goats fed with NC had higher (P < 0.05) intakes of dry matter, crude protein, neutral detergent fiber (NDF), and non-fibrous carbohydrates. There was no influence (P > 0.05) on milk production, but goats fed with OS produced milk with higher (P < 0.05) fat content and presented higher (P < 0.05) feed efficiency. There was no effect (P > 0.05) of the hay type on the nutrient intake and milk production and composition of goats, but the animals fed with MY had higher (P < 0.05) serum cholesterol levels and greater efficiency of NDF rumination. Goats fed with OS showed greater feeding and rumination efficiency. Our results indicated that both cactus species could be successfully included in the diet of low yielding dairy goats fed 18.4% concentrate.

Natural Deep Eutectic Solvent based Ultrasound-assisted extraction: A green approach for extraction of sulfhydryl and mimosine from Leucaena leucocephala (Lam) de Wit seeds.

Leucaena leucocephala (Lam.) de Wit seeds, also known as river tamarind, contain sulfhydryl compounds that exhibit antioxidant effects. However, these seeds also possess a toxic effect from mimosine. In this study, the river tamarind seeds were extracted using a natural deep eutectic solvent (NADES) based UAE. Among six NADES compositions screened, choline chloride-glycerol (ChCl-Gly) and choline chloride-sucrose (ChCl-Suc) were selected to be further optimized using a Box-Behnken Design in the RSM. The optimization of total sulfhydryl content was performed in 17 runs using three variables, namely water content in NADES (39%, 41%, and 43%), extraction time (5, 10, and 15 min), and the liquid-solid ratio (3, 5, and 7 mL/g). The highest concentration of sulfhydryls was obtained from ChCl-Gly-UAE (0.89 mg/g sample) under the conditions of a water content in NADES of 41% (v/v) and a liquid-solid ratio of 3 mL/g for 15 min, followed by that of from ChCl-Suc-UAE extract under the conditions of water content in NADES of 43% (v/v) and the liquid-solid ratio of 3 mL/g for 10 min with total sulfhydryl level was 0.67 mg/g sample. The maceration method using 30% ethanol resulted in the lowest level of sulfhydryls with a value of 0.52 mg/g. The mimosine compounds obtained in the NADES-based UAE (ChCl-Suc and ChCl-Gly) extracts were 4.95 and 7.67 mg/g, respectively, while 12.56 mg/g in the 30% ethanol-maceration extract. The surface morphology of L. leucocephala seed before and after extraction was analyzed using scanning electron microscopy. Therefore, it can be concluded that the use of ChCl-Suc and ChCl-Gly in NADES-based UAE is more selective in attracting sulfhydryl compounds than that of 30% ethanol-maceration extraction.

Levels of leucaena hay associated with cactus pear in diets for crossbred steers.

Our hypothesis is that the total replacement of ground corn grain (GCG) by cactus pear (CP) in association with 70% of leucaena hay (LH) increases dry matter (DM) intake and digestibility and nitrogen metabolism and maintains the feeding behavior of cattle. The objective was to evaluate the effects of inclusion of these feeds on the nutritional parameters and nitrogen metabolism of cattle. Eight steers, average age of 12 months, weight of 267.5 ± 15 kg, were distributed into two simultaneous 4 × 4 Latin squares according to a 2 × 2 factorial scheme, in which the first factor evaluated was different proportions of inclusion of LH (50 or 70% DM basis), and the second factor was the total replacement of GCG with CP. There was lower DM intake in animals fed with 70% LH. There was an interaction between the factors for DM digestibility, in which the animals fed CP did not differ regardless of the inclusion of LH, but for animals without CP, the greater inclusion of LH decreases DM digestibility. The inclusion of CP decreased free water intake. There was an interaction for total water intake (WI), in which the animals fed without CP presented similarity for this, while in the inclusion of CP, the animals fed 70% of LH presented higher WI. Also, lower values of chewing were observed for animals fed with CP. The replacement of GCG with CP improves the efficiency of nitrogen utilization in the rumen. The inclusion of 70% LH depresses intake.

Fermentation Patterns, Methane Production and Microbial Population under In Vitro Conditions from Two Unconventional Feed Resources Incorporated in Ruminant Diets.

In this study, four experimental treatments were evaluated: (T1) alfalfa hay + concentrate, (50:50%, DM); (T2) alfalfa hay + Leucaena leucocephala + concentrate, (30:20:50%, DM); (T3) alfalfa hay + prickly pear + concentrate, (30:20:50%, DM); and (T4) alfalfa hay + Leucaena leucocephala + prickly pear + concentrate, (30:10:10:50%, DM). NH3-N concentrations in T2 and T4 decreased when replaced with alfalfa hay in 20 and 10%, respectively. Treatments did not affect the concentration of total volatile fatty acids (TVFA) between T3 and T4 (p > 0.05), while the concentrations among T1 and T2 were different (p < 0.05). T2 showed a reduction of 25.5% in the methane production when compared to T1 (p < 0.05). The lowest concentrations of protozoa were observed in T2 and T4, which contained Leucaena leucocephala (T2) and Leucaena leucocephala + prickly pear (T4) (p < 0.05). The highest concentration of total methanogens was recorded in T1 and was different in T2, T3, and T4 (p < 0.05). Leucaena leucocephala, at an inclusion percentage of 20%, decreased the methane when compared to T1, whereas prickly pear increased methane production in relation to T1.

Effect of increasing levels of Leucaena leucocephala seeds to grass pellets on performance of grower rabbits.

The study was carried out to determine the chemical composition of composite pellets of Megathyrsus maximus containing Leucaena leucocephala seed meal at the varying level and growth responses, as well as haematological and serum biochemical of rabbits, fed the pellets for 60 days. The treatment consists of M. maximus and L. leucocephala-100:0, 90:10, 80:20, 70:30 and 60:40, respectively. Results revealed an increase (P < 0.05) in the proximate composition of the grass pellets with an increase in seed inclusion while there was a reduction (P < 0.05) in the NDF contents of the pellets. An increase in the tannin contents was recorded with an increase in seed inclusion to the grass pellets. Rabbits fed with 30 and 40% inclusions of seed in the grass pellets had similar weight gain while the lowest feed conversion ratio was recorded in rabbits fed grass with 30% seed inclusion. Packed cell volume, RBC and lymphocyte in rabbits were altered with feeding grass seed pellet (P < 0.05), although no particular pattern was followed. Total protein, globulin and urea contents were reduced in the rabbits as the contents of the seeds in the grass pellets increased. Albumin contents in pellets with 30% of seeds were higher in the rabbits fed the pellets above other treatments. It can be concluded that increasing the seed meal level up to 30% in grass pellets supported growth response without inflicting any side effects on the health indices of the rabbits.

Porous hydrogel composite with whey protein isolate and galactomannans of Leucaena leucocephala (subabul) seeds: Stability, rheological, thermal, and morphological characterization.

The present study was aimed at curating a porous KCl crosslinked hydrogel with purified subabul galactomannans (SG) from the defatted seeds of Leucaena leucocephala (subabul) and κ-carrageenan (κC) by inducing whey protein isolate (WPI). WPI showed 345% foam overrun and minimal foam drainage (%) at 70°C when whipped for 5 min at pH 6.8 in the hydrogel prepared with 6.5% w/v SG + 1% w/v κC + 0.63% w/v KCl + 2% w/v WPI. The SG and WPI incorporated porous hydrogel (SGWP) showed maximum G' (3010 Pa) and frequency independence (>30 Hz) at 65°C. NMR (1 H), scanning electron microscopy, and thermal characterization of SGWP showed a crosslinked microporous gel network formation. SGWP had high water uptake rate (Q) (432%) at 45°C. The stability of SGWP at neutral pH and high temperature (65°C) added an impetus to this study as it could be used for a wide range of applications. Hence the protein-polysaccharide complexation improvised the functional properties of the porous hydrogels. The results suggested a possible valorization of galactomannans from subabul, a forest resource, into a porous hydrogel suitable as a matrix for delivery of bioactive(s) or an aerogel for multifarious industrial applications. PRACTICAL APPLICATION: A porous hydrogel is defined as a solid, or collection of solid bodies, with sufficient open space to enable a fluid to pass through or around them. Leucaena leucocephala seed (forest resource) galactomannans are non-starch polysaccharides having weak gelling capacity. Whey protein isolates (WPI) are a dairy industry byproduct having excellent foaming properties. Incorporation of WPI in the hydrogel prepared with subabul galactomannan and κ-carrageenan using KCl as a crosslin could form a stable porous structure having high water uptake rate (Q) at neutral pH and elevated temperature. The hydrogel so developed could be a step toward circular economy.

Effects of supplementing rice straw with two fodder tree leaves and their combinations on voluntary feed intake, growth, and nitrogen utilization in sheep.

Fodder tree leaves (FTL) are limitless nutrient resources that provide high-quality feed, particularly during the dry season, improving animal diets, and reducing the use of concentrates in ruminant livestock farming. In order to determine the benefits of FTL, two experiments were conducted to measure the voluntary feed intake, growth performance, and nitrogen utilization of forest-type (FT) sheep fed rice straw (RS) and supplemented with either Leucaena leucocephala (LEU) or Samanea saman (SAM) or their equal combination (LS). For the growth trial (Experiment 1), 12 male FT sheep with mean initial body weight (BW) of 17.0 ± 1.0 kg (mean ± SD) were randomly assigned to one of four dietary treatments in a Completely Randomized Design. The diets were Urea-treated RS (UTS) (Control), RS + L (LEU), RS + S (SAM), and RS + 50% L + 50% S (LS). After 14 d of adjustment period, feed intakes and refusals were recorded daily, whereas BW was recorded bi-weekly for 12 wk. Four rams weighing 17.0 ± 1.0 kg BW were randomly assigned to the four treatments over a four period in a repeated (4 × 4) Latin square design to estimate the nitrogen (N) balance study (Experiment 2). Treatment diets were the same as that of Experiment 1. Dry matter intake of straw was highest (P = 0.0001) for sheep fed UTS. However, combining L with S increased (P = 0.0001) straw DM intake compared to feeding L or S alone. There was no significant difference (P > 0.05) in total feed intake between sheep offered UTS and LS, but both were significantly higher (P = 0.0001) than those offered LEU and SAM. Body weight gain (3.70 kg) and growth rate (196.15 g/d) were highest (P = 0.0001) for sheep offered LS compared to the other treatment groups. Values for N balance differed (P = 0.0001) among treatment diets. N balance for LUE and LS supplemented diets were higher than that of SAM but all were higher (P = 0.0001) than those offered UTS. Leucaena and Samanea leaves could, therefore, be utilized as supplement to poor-quality straws to improve the productivity of small ruminants especially during the long dry seasons in the tropics.

Four Invasive Plant Species in Southwest Saudi Arabia Have Variable Effects on Soil Dynamics.

Predicting the direction and magnitude of change in soil dynamics caused by invasive plant species has proven to be difficult because these changes are often reported to be species- and habitat-specific. This study was conducted to determine changes in three soil properties, eight soil ions, and seven soil microelements under established stands of four invasive plants, Prosopis juliflora, Ipomoea carnea, Leucaena leucocephala, and Opuntia ficus-indica. Soil properties, ions, and microelements were measured in sites invaded by these four species in southwest Saudi Arabia, and these values were compared to the results for the same 18 parameters from adjacent sites with native vegetation. Because this study was conducted in an arid ecosystem, we predict that these four invasive plants will significantly alter the soil properties, ions, and microelements in the areas they invaded. While the soils of sites with the four invasive plant species generally had higher values for soil properties and ions compared to sites with native vegetation, in most instances these differences were not statistically significant. However, the soils within sites invaded by I. carnea, L. leucocephala, and P. juliflora had statistically significant differences for some soil parameters. For sites invaded by O. puntia ficus-indica, no soil properties, ions, or microelements were significantly different compared to adjacent sites with native vegetation. Sites invaded by the four plant species generally exhibited differences in the 11 soil properties, but in no instance were these differences statistically significant. All three soil properties and one soil ion (Ca) were significantly different across the four stands of native vegetation. For the seven soil microelements, significantly different values were detected for Co and Ni, but only among stands of the four invasive plant species. These results indicate that the four invasive plant species altered soil properties, ions, and microelements, but for most of the parameters we assessed, not significantly. Our results do not support our initial prediction, but are in general agreement with previous published findings, which indicate that the effects of invasive plants on soil dynamics vary idiosyncratically among invasive species and among invaded habitats.

Supplementation of Water Spinach (Ipomoea aquatica) on the utilization of Mimosa pigra and Leucaena leucocephala leaf for in vitro fermentation.

Background and Aim: Ipomoea aquatica (Water Spinach) is the most potential for livestock growth performance, including chickens, pigs, cattle, and goats, especially in a tropical country like Cambodia. It is not only an alternative feed source but also one kind of supplemented feed for goat raising. Supplementation with Water Spinach in the utilization of low-quality tree foliage results in an increase in dry matter intake in goat production. This study aimed to identify the effectiveness of supplementation of Water Spinach in the utilization of Mimosa pigra and Leucaena leucocephala leaf in in vitro fermentation. Materials and Methods: The study was designed according to a 2 × 2 factorial arrangement in randomized design of seven treatments with different ratios consisted of different three types of dietary treatments, including M. pigra, L. leucocephala, and Water Spinach. The treatments were arranged according to a completely randomized design and were as follow: T1 = M. pigra leaf (100%); T2 = L. leucocephala leaf (100%); T3 = M. pigra leaf and L. leucocephala leaf (50% and 50%); T4 = M. pigra leaf and Water Spinach (99.5% and 0.5%); T5 = L. leucocephala leaf and Water Spinach (99.5% and 0.5%); T6 = M. pigra leaf and Water Spinach (99% and 1%); and T7 = L. leucocephala leaf and Water Spinach (99% and 1%). A total of 200 mg (dry matter) of dietary treatments were prepared in a 60 mL syringe. Each treatment was replicated 3 time. Gas recording of each treatment lasted for 3 days. In vitro was performed for 72 h, was followed by Makkar method. Gas production was recorded at 2, 4, 8, 12, 24, 36, 48, and 72 h of incubation by using strict anaerobic technique. A mixture of rumen fluid and dietary treatments were carried out under continuous flushing with CO2 in sharking incubator at 39°C. After incubating for 72 h, the ammonia concentration (NH3-N) was measured and recorded to identify pH, nutrient digestibility, and ammonia concentration (NH3-N). Results: Nutrient digestibility of the treatment with Water Spinach supplement in the utilization of L. leucocephala was obtained at a higher digestibility than treatment with M. pigra (p < 0.05). Gas production was different between groups (p < 0.05). Treatment with only M. pigra leaf had the highest gas production (A), while treatment with Water Spinach supplementation had the lowest gas production (A). At 0-24 h, the treatment with L. leucocephala leaf and Water Spinach 0.5% had the highest gas production, but after 24 h, M. pigra leaf and Water Spinach 1% and L. leucocephala leaf and Water Spinach 0.5% produced more gas compared to the other treatments (p < 0.05). Conclusion: The supplementation of Water Spinach 1% in treatment with M. pigra and L. leucocephala leaf resulted in increased degradability, gas production, and NH3-N concentration without a change in the pH value rumen condition. Based on these results, it is recommended that the level of Water Spinach supplementation should be 1% of dietary intake. Future studies should consider investigating the rumen ecology associated with Water Spinach supplementation. Feeding with Water Spinach remains a good supplement for ruminant performance; therefore, further studies should be conducted using Water Spinach in ruminant feeding in both metabolic and feeding trials.

An innovative insecticidal approach based on plant protease inhibitor and Bt protoxins inhibits trypsin-like activity in zebrafish.

The Leucaena leucocephala trypsin inhibitor (LTI) + Bacillus thuringiensis (Bt) protoxins mix has been proposed as a novel larvicide agent in order to control the vector mosquito of dengue virus, Aedes aegypti, in their aquatic breeding sites. However, use of this insecticide formulation has raised concerns about its impacts on aquatic biota. In this context, this work aimed to assess the effects of LTI and Bt protoxins, separately or in combination, in zebrafish, in regard to the evaluation of toxicity at early life stages and to the presence of LTI inhibitory effects on intestinal proteases of this fish. Results showed that LTI and Bt concentrations (250 mg/L, and 0.13 mg/L, respectively), and LTI + Bt mix (250 mg/L + 0.13 mg/L) - 10 times superior to those with insecticidal action - did not cause death nor did it induce morphological changes during embryonic and larval development (3 to 144 h post-fertilization) of zebrafish. Molecular docking analyses highlighted a possible interaction between LTI and zebrafish trypsin, especially through hydrophobic interactions. In concentrations near to those with larvicidal action, LTI (0.1 mg/mL) was able to inhibit in vitro intestinal extracts of trypsin in female and male fish by 83 % and 85 %, respectively, while LTI + Bt mix promoted trypsin inhibition of 69 % in female and 65 % in male ones. These data show that the larvicidal mix can potentially promote deleterious effects to nutrition and survival in non-target aquatic organisms, especially those with trypsin-like dependent protein digestion.

Effect of Cadmium on Macro and Micronutrient Uptake and Translocation by Leucaena leucocephala.

Environmental contamination with Cadmium (Cd) is of great concern due to its hazardous effects on living organisms.Query In the present research, Leucaena leucocephala plants were exposed to Cd concentrations of 5, 10, and 15 mg/L to determine their potential use in Cd remediation. Different parameters including Cd uptake, macro/micronutrient content, chlorophyl, and catalase production were determined. Results indicated that Cd uptake by L. leucocephala roots did not show a significant difference between treatments. However, a significant increase in Cd content (Tukey´s HSD) was observed in stems as Cd levels in the media augmented. The highest Cd content (830 ± 20 mg/kg) was determined in stems of plants exposed to 15 mg/L Cd, and no Cd was detected in leaves. Data showed that as Cd concentration increased in the media, Ca, Mg, K, Zn, and Mn decreased. Moreover, while the presence of Cd reduced catalase activity in roots, chlorophyll production was not affected.

Therapeutic Effect and Immune Changes after Treatment of Hymenolepis nana-Infected BALB/c Mice with Compounds Isolated from Leucaena leucocephala.

BACKGROUND/PURPOSE: Hymenolepis nana is globally distributed. Leucaena leucocephala has been studied as a treatment, including the nematodes and protozoa, but no research results are related to cestodes. Therefore, the aim of this study was to target H. nana. METHODS: The natural components of L. leucocephala were isolated and added to H. nana, which was cultured in vitro, to observe changes in the mortality, motility, and morphology. BALB/c male mice infected with H. nana were treated with effective components of L. leucocephala for 10 days, and the changes were recorded. After the mice were sacrificed, the spleen weight was measured, and a primary culture was performed for the subsequent cytokine and chemokine testing. RESULTS: The experiment found that 132-hydroxy-(132-S)-pheophytin a and aristophyll-C have clear cestocidal effects in vitro. 132-hydroxy-(132-S)-pheophytin a has been shown to be effective at reducing parasite populations and eliciting host immune responses in vivo. IL-2, IL-4, IL-5, IL-6, IL-10, IL-13, IL-17, MCP-1, IFN-γ, TNF-α, MIP-1α, and GM-CSF in 132-hydroxy-(132-S)-pheophytin a were significantly increased after stimulation, while IL-1α, IL-1ß, IL-3, IL-12p70, and RANTES were unchanged. CONCLUSIONS: The investigation shows that components of L. leucocephala have actual cestocidal activity against H. nana.

Evolution of novel strains of Ensifer nodulating the invasive legume Leucaena leucocephala (Lam.) de Wit in different climatic regions of India through lateral gene transfer.

More than 200 root-nodule bacterial strains were isolated from Leucaena leucocephala growing at 42 sampling sites across 12 states and three union territories of India. Genetic diversity was observed among 114 strains from various climatic zones; based on recA, these were identified as strains of Ensifer, Mesorhizobium, Rhizobium, and Bradyrhizobium. In multilocus sequence analysis (MLSA) strains clustered into several novel clades and lineages. Ensifer were predominant nodulating genotype isolated from majority of alkaline soils, while Mesorhizobium and Rhizobium strains were isolated from a limited sampling in North-Eastern states with acidic soils. Positive nodulation assays of selected Ensifer representing different genetic combinations of housekeeping and sym genes suggested their broad host range within the closely related mimosoid genera Vachellia, Senegalia, Mimosa, and Prosopis. Leucaena selected diverse strains of Ensifer and Mesorhizobium as symbionts depending on available soil pH, climatic, and other edaphic conditions in India. Lateral gene transfer seems to play a major role in genetic diversification of Ensifer exhibited in terms of Old World vs. Neotropical genetic make-up and mixed populations at several sites. Although Neotropical Ensifer strains were most symbiotically effective on Leucaena, the native Ensifer are promiscuous and particularly well-adapted to a wide range of sampling sites with varied climates and edaphic factors.

Diversity, Succession and Seasonal Variation of Phylloplane Mycoflora of Leucaena leucocephala in Relation to Its Leaf Litter Decomposition.

To address international food security concerns and sustain a growing global population, global agricultural output needs to increase by 70% by the year 2050. Current agricultural techniques to increase crop yields, specifically the application of chemicals, have resulted in a wide range of negative impacts on the environment and human health. The maintenance of good quality soil organic matter, a key concern in tropical countries such as India, requires a steady input of organic residues to maintain soil fertility. A tree with many uses, Leucaena leucocephala, has attracted much attention over the past decades. As per our literature review, no research has been conducted examining Leucaena leucocephala leaves for their fungal decomposition and their use as green manure. A study of the fungal colonization of Leucaena leucocephala leaves at various stages of decomposition was conducted to get an insight into which fungi play a critical role in the decomposition process. In total, fifty-two different species of fungi were isolated. There was an increase in the percentage of fungus occurrences as the leaves senesced and then finally decomposed. Almost all decomposition stages were characterized by a higher percentage occurrence of Deuteromycetes (75.47%) and by a lower rate of Ascomycetes (9.43%). A gradual increase of basidiomycetes such as unidentified sclerotia and Rhizoctonia solani was seen as the leaves senesced and finally decomposed. In the moist chamber, Didymium nigripes was the only Myxomycete isolated from completely decomposed leaves. In the present study, on average, there were more fungi in wet seasons than in the dry seasons.

Alien invasive Leucaena leucocephala successfully acquires nutrients by investing in below-ground biomass compared to native Vachellia nilotica in nutrient-amended soils in South Africa.

Soils in grasslands and savannas of southern Africa are acidic and nutrient-poor. Legume plants, such as Vachellia nilotica and alien invasive Leucaena leucocephala, are a major component of the vegetation there. Vachellia nilotica can establish in drought-prone environments, and is invasive in high rainfall areas. Leucaena leucocephala is an emerging invasive in South Africa and is ranked among the world's 100 most invasive alien species. Alien plants can invade native habitats through their adaptability to low-resource soils, and thus can out-compete and displace native vegetation. We investigated the effects of phosphorus (P) deficiency and soil acidity on legume-microbe symbiosis, nitrogen (N) nutrition and carbon (C) growth costs of these two legumes in grassland soils. We used as inoculum and growth substrate soils collected from a long-term (>65 years) nutrient and lime-addition trial, the Veld Fertilizer Trial (VFT), located at Ukulinga Research Farm near Pietermaritzburg in South Africa. We used soils from three VFT treatments: soils fertilized with superphosphate (336 kg ha-1) applied once per year (+P), soils fertilized with superphosphate (336 kg ha-1) applied once per year with dolomitic lime (2250 kg ha-1) applied once every 5 years (P+L) and soils with no superphosphate and no dolomitic lime applications (Control). Seeds of V. nilotica and L. leucocephala were germinated and grown independently in these soils in green house conditions and harvested after 125 days for measurement of growth, legume-microbe symbiosis, N nutrition and C growth costs. Results showed that the two legumes had different growth adaptations. Vachellia nilotica grown in control soils and +P soils nodulated with various Burkholderia spp., while L. leucocephala did not nodulate in all soil treatments. Both legumes utilized for growth both atmospheric- and soil-derived N across all treatments thereby decreasing C growth costs. Vachellia nilotica grown in +P soils accumulated the most biomass and N nutrition. Leucaena leucocephala maximized specific N assimilation rates by investing in below-ground biomass accumulation in control soils. This shows that L. leucocephala possesses traits that are successful in acquiring nutrients by investing in below-ground biomass and relying on utilization of N from both the soil and the atmosphere.

Methods of Mimosine Extraction from Leucaena leucocephala (Lam.) de Wit Leaves.

Mimosine is a nonprotein amino acid biosynthesized from OAS (O-acetylserine) and 3H4P (3-hydroxy-4-pyridone or its tautoisomer 3,4-dihydroxypyridine). This amino acid constitutively occurs in all parts of Leucaena leucocephala (Lam.) de Wit plants and is found at higher concentrations in seeds and leaves. This metabolite has several useful activities, such as antioxidant, allelochemical, insecticidal, antimicrobial, metal chelating, and antitumor. Mimosine is well studied in biomedical research due its ability to inhibit cells in the late G1 phase and to induce cell apoptosis. Two simple methods of mimosine extraction from leucaena leaves, pulverized and whole maceration, are described herein in detail.

Rainwater harvesting and Leucaena leucocephala biomass rates effects on soil moisture, water use efficiency and Sorghum bicolor [(L.) Moench] productivity in a semi-arid area in Zimbabwe.

BACKGROUND: Sorghum is one of the major staple crops in Sub Saharan Africa but its production is mainly limited by moisture stress, frequent droughts and soil infertility, especially in the smallholder farming systems. This raises the need to develop climate smart options to improve sorghum production. The objective was to assess the effects of rainwater harvesting and use of different Leucaena leucocephala biomass rates on soil moisture content, rainwater use efficiency, and stover and grain yields in two sorghum varieties (Macia and SV1). The experiment was laid as a randomized complete block design in split-split plot arrangement from 2017/2018 to 2019/2020 season. RESULTS: The results show that tied contour (TC) and infiltration pits (IPs) significantly (P < 0.05) increased soil moisture content than standard contour (SC). Soil moisture content increased gradually with the increase in soil depth (20-40 cm > 0-20 cm), with 2018/2019 season having the maximum soil moisture content. Soil moisture content also increased with the increase in application rates of Leucaena biomass. Grain and stover yields were significantly (P < 0.05) increased by all Leucaena biomass application rates with higher yield observed in 2018/2019 season. SC had significantly lower grain and stover yields at all Leucaena biomass application rates. TC and IPs had comparable rainwater use efficiency compared to SC. Rainwater use efficiency increased with application rates of Leucaena biomass across all seasons and varieties. CONCLUSION: TC and IPs are better adaptive mechanisms against drought spells in semi-arid areas and can be combined with 10 t ha-1 of Leucaena biomass due to better yield increments realized. © 2022 Society of Chemical Industry.

Anthelmintic Effect of Leucaena leucocephala Extract and Its Active Compound, Mimosine, on Vital Behavioral Activities in Caenorhabditis elegans.

Helminth infections continue to be a neglected global threat in tropical regions, and there have been growing cases of anthelmintic resistance reported towards the existing anthelmintic drugs. Thus, the search for a novel anthelmintic agent has been increasing, especially those derived from plants. Leucaena leucocephala (LL) is a leguminous plant that is known to have several pharmacological activities, including anthelmintic activity. It is widely known to contain a toxic compound called mimosine, which we believed could be a potential lead candidate that could exert a potent anthelmintic effect. Hence, this study aimed to validate the presence of mimosine in LL extract and to investigate the anthelmintic effect of LL extract and mimosine on head thrashing, egg-laying, and pharyngeal pumping activities using the animal model Caenorhabditis elegans (C. elegans). Mimosine content in LL extract was confirmed through an HPLC analysis of spiking LL extract with different mimosine concentrations, whereby an increasing trend in peak heights was observed at a retention time of 0.9 min. LL extract and mimosine caused a significant dose-dependent increase in the percentage of worm mortality, which produced LC50s of 73 mg/mL and 6.39 mg/mL, respectively. Exposure of C. elegans to different concentrations of LL extract and mimosine significantly decreased the head thrashing, egg-laying, and mean pump amplitude of pharyngeal pumping activity. We speculated that these behavioral changes are due to the inhibitory effect of LL extract and mimosine on an L-type calcium channel called EGL-19. Our findings provide evidential support for the potential of LL extract and its active compound, mimosine, as novel anthelmintic candidates. However, the underlying mechanism of the anthelmintic action has yet to be elucidated.

Influence of mechanical operation on the biodelignification of Leucaena leucocephala by xylanase treatment.

This study aimed at energy reduction during pulping of L. leucocephala by passing the wood chips through an impressafiner followed by xylanase pretreatment. An impressafiner compressed the chips and converted them into spongy materials. Wood chips of L. leucocephala with or without de-structuring and de-structured wood chips followed by enzymatic treatment were subjected to Kraft pulping at different temperatures varying from 135 to 170 °C and active alkali varying from 12 to 20% (as Na2O) to observe effect on screened pulp yield and kappa number. The de-structured wood chips followed by enzymatic treatment produced a pulp yield of 48.2% and kappa number 18.6. L. leucocephala without de-structuring produced a pulp yield of 50.1% and kappa number 23.7. When the pulp was subjected to oxygen delignification to reduce kappa number in the vicinity of 18.6, pulp showed shrinkage by 6.64% compared to Kraft pulp of de-structured wood chips followed by enzymatic treatment. Kraft pulp produced from de-structured wood chips of L. leucocephala followed by enzymatic treatment showed net saving of US$ 163.15 per digester over Kraft pulp produced without de-structuring of wood chips of L. leucocephala. Moreover, the pulp obtained by de-structuring followed by enzymatic treatment showed improvement in pulp brightness and physical strength properties including tensile, tear, and burst index significantly compared to pulp obtained without de-structuring.