Seasonality,habitat type and locality influenced bird assemblage structure in Nigeria

This is the first report of the avian assemblage in the study area of Dutse, Nigeria. In addition to recording bird species, the effects of season, dominant vegetation structure, locality and anthropogenic activities on bird abundance, species richness and diversity were investigated. Using the point transect method, 264 points on 48 km of transect were used to count birds between 06:30 and 11:00 from August 2015 to February 2016. A total of 122 bird species of 41 families were recorded. Highest bird species richness was recorded in Warwade, highest abundance in Model, and highest diversity in Malamawa. The dry season and woodland habitat showed higher bird species richness, abundance and diversity than the wet season and shrubland habitat. Tree density was more important in increasing bird abundance than shrub density. Small-scale anthropogenic activities and habitat modification, such as farming, grazing, wood removal and human interference did not appear to have impacted the birds; however, loss of high tree-density woodland habitats may pose a major threat to the bird community in Dutse. The presence of birds of concern in the area suggests the need for conservation efforts of avifauna and as well as the forested habitats in Dutse.     

Cellulose Derivatives Enhanced Stability of Alginate-Based Beads Loaded with <Emphasis Type="Italic">Lactobacillus plantarum</Emphasis> LAB12 against Low pH,High Temperature and Prolonged Storage

The susceptibility of probiotics to low pH and high temperature has limited their use as nutraceuticals. In this study, enhanced protection of probiotics via microencapsulation was achieved. Lactobacillus plantarum LAB12 were immobilised within polymeric matrix comprised of alginate (Alg) with supplementation of cellulose derivatives (methylcellulose (MC), sodium carboxymethyl cellulose (NaCMC) or hydroxypropyl methylcellulose (HPMC)). L. plantarum LAB12 encapsulated in Alg-HPMC(1.0) and Alg-MC(1.0) elicited improved survivability (91%) in simulated gastric conditions and facilitated maximal release (～100%) in simulated intestinal condition. Alg-HPMC(1.0) and Alg-MC(1.0) significantly reduced (P < 0.05) the viability loss of LAB12 (viability loss <7%) when compared to Alg alone (viability loss <13%) under extreme temperatures (75 and 90 °C). Four-week storage of encapsulated LAB12 at 4 °C yielded viable counts >7 log CFU g^?1. Alg-MC and Alg-HPMC improved the survival of LAB12 against simulated gastric condition (9.24 and 9.55 log CFU g^?1, respectively), temperature up to 90 °C (9.54 and 9.86 log CFU g^?1, respectively) and 4-week of storage at 4 °C (8.61 and 9.23 log CFU g^?1, respectively) with sustained release of probiotic in intestinal condition (>9 log CFU g^?1). These findings strongly suggest the potential of cellulose derivatives supplemented Alg bead as protective micro-transport for probiotic strains. They can be safely incorporated into new functional food or nutraceutical products.     

Diosbulbin d and 8-epidiosbulbin e acetate,norclerodane diterpenoids from dioscorea bulbifera tubers

From tubers of Dioscorea buibifera L. var sativa a new 18-norclerodane diterpenoid, 8-epidiosbulbin E acetate, has been isolated, besides the previously known norditerpenoid, diosbulbin D, and its structure established by spectroscopic means.     

Embryo apoptosis identification: Oocyte grade or cleavage stage?

Apoptosis is a programed cell death that is vital for tissue homeostasis. However, embryo apoptosis had been known to be related to embryo fragmentation which should be avoided in in vitro fertilization (IVF). The purpose of this study was to evaluate the relationship of embryo apoptosis with the grade of immature oocytes and cleavage stage of in vitro produced (IVP) cattle embryos. This study consisted of 345 oocytes collected through ovary slicing. Immature oocytes were graded as A, B and C. This grading was based on cumulus cell thickness and compactness. All oocytes then underwent an in vitro maturation (IVM) procedure. An IVF was done 24 h after IVM culture. Prior to staining, stage of cleaved embryos was determined and classified as either 2, 4, 8 or >8-cell embryo stage. Apoptosis status of cleaved IVP embryos was determined by using annexin V-FITC staining technique at 48 and 72 h post insemination (hpi). Apoptosis status for each embryo was classified as either early or late. The result showed that there was no significant difference (p > 0.05) of apoptosis status among grade A, B and C embryos. All grades of oocytes showed embryo apoptosis where 1.5% late apoptosis for grade A, 4.5% and 10.4% of early and late apoptosis for grade B and grade C. Early apoptosis was not seen in grade A embryo. We also noted no significant difference (p > 0.05) of apoptosis status between 2, 4, 8 and >8-cell embryo stage. Early apoptosis was also not seen in >8-cell stage. Even though there were no differences in apoptosis expression between the three classes, the cleavage rate of grade A oocytes was significantly higher (p < 0.01) than grade B and grade C. In conclusion, the apoptosis expression in the embryo can occur regardless of the oocyte quality and the cleavage stage of the embryo produced.Abbreviations: ART, assisted reproductive technologies; BO, Brackett and Oliphant; BSA, bovine serum albumin; CaI, calcium ionophore; CC, cumulus cells; COC, cumulus–oocyte complex; CO₂, carbon dioxide; CR1aa, Charles Rosenkran’s 1 amino acid; DNA, deoxyribonucleic acid; DO, denuded oocyte; EA, early apoptosis; FBS, fetal bovine serum; FITC, fluorescein isothiocyanate; FSH, follicle stimulating hormone; GSH, glutathione; hpi, hours post insemination; IVC, in vitro culture; IVF, in vitro fertilization; IVM, in vitro maturation; IVP, in vitro produced; LA, late apoptosis; LH, luteinizing hormone; PBS, phosphate buffered saline; PI, propidium iodide; PS, phosphatidylserine; TUNEL, terminal deoxynucleotidyl transfer-mediated dUTP nick end-labeling.     

Fusarium fujikuroi associated with stem rot of red‐fleshed dragon fruit (Hylocereus polyrhizus) in Malaysia

Stem rot was recorded as one of serious diseases of red‐fleshed dragon fruit, (Hylocereus polyrhizus), in Malaysia. Fusarium fujikuroi was recovered from stem rot lesion of H. polyrhizus and the species was identified using TEF1‐α sequence and mating study. From maximum likelihood phylogenetic tree using combined TEF1‐α and β‐tubulin sequences, the F. fujikuroi isolates from stem rot were grouped according to three geographical locations, namely Peninsular Malaysia, Sabah and Sarawak. Phylogenetic analysis indicated that F. fujikuroi isolates from stem rot of H. polyrhizus were clustered separately from F. fujikuroi isolates from rice because of intraspecific variation. From amplification of MAT allele‐specific primers, 20% of the isolates carried MAT‐1 allele while 80% carried MAT‐2 allele. From isolates that carried MAT‐1 allele, 65% crossed‐fertile with MP‐C (mating population of F. fujikuroi) tester strain while for MAT‐2 allele, 56% crossed‐fertile with MP‐C. None of the isolates were identified as MP‐D (mating population of F. proliferatum). Pathogenicity test conducted on 40 representative isolates showed that the stem rot symptoms were similar with the symptoms observed in the field, and can be categorized as low, moderate and high aggressiveness, which indicated variation in pathogenicity and virulence among the isolates. This study provides novel findings regarding Fusarium species associated with stem rot of H. polyrhizus and indicated that F. fujikuroi as a new causal pathogen of the disease.     

Production and partial characterization of biosurfactant produced by Streptomyces sp. R1

The present study focused on developing a wild-type actinomycete isolate as a model for a non-pathogenic filamentous producer of biosurfactants. A total of 33 actinomycetes isolates were screened and their extracellular biosurfactants production was evaluated using olive oil as the main substrate. Out of 33 isolates, 32 showed positive results in the oil spreading technique (OST). All isolates showed good emulsification activity (E₂₄) ranging from 84.1 to 95.8%. Based on OST and E₂₄ values, isolate R1 was selected for further investigation in biosurfactant production in an agitated submerged fermentation. Phenotypic and genotypic analyses tentatively identified isolate R1 as a member of the Streptomyces genus. A submerged cultivation of Streptomyces sp. R1 was carried out in a 3-L stirred-tank bioreactor. The influence of impeller tip speed on volumetric oxygen transfer coefficient (k _L a), growth, cell morphology and biosurfactant production was observed. It was found that the maximum biosurfactant production, indicated by the lowest surface tension measurement (40.5 ± 0.05 dynes/cm) was obtained at highest k _L a value (50.94 h⁻¹) regardless of agitation speed. The partially purified biosurfactant was obtained at a concentration of 7.19 g L⁻¹, characterized as a lipopeptide biosurfactant and was found to be stable over a wide range of temperature (20–121 °C), pH (2–12) and salinity [5–20% (w/v) of NaCl].

     

Esterification of Levulinic Acid Using ZrO<Subscript>2</Subscript>-Supported Phosphotungstic Acid Catalyst for Ethyl Levulinate Production

Ethyl levulinate (EL) is a versatile bio-based chemical with various applications such as fragrance and flavoring agents and also fuel blending component. EL can be produced through catalytic esterification of levulinic acid (LA) with ethanol. Herein, a series of zirconia (ZrO₂)-supported phosphotungstic acid (HPW) (HPW/Zr) catalyst, 15-HPW/Zr, 20-HPW/Zr, and 25-HPW/Zr, were prepared, characterized, and tested for EL production. The physicochemical properties of catalysts were characterized using Fourier-transformed infrared (FTIR) spectroscopy, x-ray diffraction (XRD), field emission scanning electron microscope (FESEM), N₂ physisorption, and ammonia temperature-programmed desorption (NH₃-TPD). The effect of reaction parameters: reaction time, temperature, catalyst loading, and molar ratio of LA to ethanol was inspected on LA conversion and EL yield. The catalyst with high surface area and high acidity seemed suitable for EL production. Among the catalysts tested, 20-HPW/Zr exhibited the highest EL yield of 97.3% at the following conditions: 150 °C, 3 h, 1.0 g of 20-HPW/Zr and 1:17 M ratio of LA to ethanol. The 20-HPW/Zr could be reused for at least four times with insignificant decrease in the EL yield. This study demonstrates the potential of ZrO₂-supported HPW for bio-based alkyl levulinate production at mild process conditions.     

Optimization of Biomass Conversion to Levulinic Acid in Acidic Ionic Liquid and Upgrading of Levulinic Acid to Ethyl Levulinate

Levulinic acid (LA) is a versatile platform chemical that can be derived from biomass as an alternative to fossil fuel resources. Herein, the optimization of LA production from glucose and oil palm fronds (OPF) catalyzed by an acidic ionic liquid; 1-sulfonic acid-3-methyl imidazolium tetrachloroferrate ([SMIM][FeCl₄]) have been investigated. Response surface methodology based on Box-Behnken design was employed to optimize the LA yield and to examine the effect and interaction of reaction parameters on the LA production. The reaction parameters include reaction temperature, reaction time, feedstock loading, and catalyst loading. From the optimization study, the predicted mathematical models for LA production from glucose and OPF covered more than 90 % of the variability in the experimental data. At optimum conditions, 69.2 % of LA yield was obtained from glucose, while 24.8 % of LA yield was attained from OPF and registered 77.3 % of process efficiency. The recycled [SMIM][FeCl₄] gave sufficient performance for five successive cycles. Furthermore, the optimum LA produced from glucose and OPF can be directly converted to ethyl levulinate through esterification over the [SMIM][FeCl₄] catalyst. This study highlights the potential of [SMIM][FeCl₄] for biorefinery processing of renewable feedstocks at mild process conditions.