Morphology and distribution of species of the family Cucurbitaceae in Akwa Ibom State, Nigeria

A study of the family Cucurbitaceae in Akwa Ibom State, Nigeria, was carried out in 15 Local Government Areas in different ecological zones across the State, where collections were made between May 2017 and June 2018. A total of eleven species in nine genera were collected: Citrullus lanatus, Citrullus mucosospermus, Cucumis sativus, Cucurbita maxima, Lagenaria siceraria, Lagenaria sphaerica, Luffa aegyptiaca, Momordica charantia, Siraitia africana, Telfairia occidentalis, and Trichosanthes cucumerina. Variation in morphology were seen in the investigated species in the stem shape that were cylindrical or angular, the compound or simple types of leaves, the indumentum of the leaf, the acute or acuminate leaf apices, the yellow or white petals, the cylindrical, spherical or irregular fruit shape, the lanceolate or irregular seed shape, and the pubescent or smooth seed. Cultivated cucurbits collected were 65% of the species investigated, while 35% occurred in the wild. A survey of the Cucurbitaceae collections in the Forest Herbarium Ibadan showed only four species recorded for Akwa Ibom State, of which only Luffa aegyptica was identified and collected in the course of this work. More cultivation should be encouraged, as this will serve as a conservation measure for cucurbits in the State.

Production of bacterial cellulose using Gluconacetobacter kombuchae immobilized on Luffa aegyptiaca support

The present work report for the first time on the production of bacterial cellulose (BC) using natural loofa sponge (Luffa aegyptiaca) as a scaffold for the immobilization of Gluconacetobacter kombuchae. Bacterial cellulose (BC) are recently gained more attention in several fields including biological and biomedical applications due to their outstanding physico-chemical characteristics including high thermal stability, easy biodegradability, good water holding capacity, high tensile strength, and high degree of polymerization. The increase in requirement of alternative method for the enhancement of BC production under economical aspect develops a positive impact in large scale industries. In this study, Luffa aegyptiaca (LA) was introduced in a separate fermentation medium so as to enhance the concentration of BC production by Gluconacetobacter kombuchae. Different process/medium parameters such as initial pH, static/shaking condition, inoculum size, nitrogen source, C/N ratio, supplements (ethanol and acetic acid) were analysed for the production of bacterial cellulose using LA support. The maximum yield of BC was obtained using following condition: culturing condition -shaking; initial pH − 5.5; nitrogen source- yeast extract, C/N ratio – 40 and supplement—ethanol. The characterization of the BC was examined using Fourier Transform Infra-Red spectroscopy and thermo gravimetric analysis. The biofilm formation on the surface of LA was examined by SEM photographs. Thus, implementation of LA as a support in shaking fermentation under suitable medium/process variables enhanced the BC production.

Chemical composition of Luffa aegyptiaca Mill., Agave durangensis Gentry and Pennisetum sp.

The particleboard industry faces problems of wood shortage, which has led to the use of non-wood lignocellulosic materials. Furthermore, there is also interest in looking for materials that improve their physical and mechanical properties. The species Luffa aegyptiaca Mill. (fruit), Agave durangensis Gentry (bagasse) and Pennisetum sp. (plant, leaves and stem) could be used in the elaboration of wood-based particleboards. The aim of this study is to determine the feasibility of using these materials to produce particleboards in accordance with their chemical composition. Five materials were studied, A. durangensis (bagasse), L. aegyptiaca (fruit) and Pennisetum sp. (whole plant, leaves and stem). Extractives, holocellulose, Runkel lignin and ash content was determined. The pH of the fibers was also measured and a microanalysis of the ash was performed. ANOVA and Kruskal-Wallis tests were carried out, in addition Tukey and Dunn tests for group comparison were performed. Pennisetum sp. leaves presented the highest total extractives and ash content, while L. aegyptiaca fruit and A. durangensis bagasse had the highest both content of holocellulose and Runkel lignin respectively. The lowest pH was presented by the L. aegyptiaca fruit, while the highest was from the Pennisetum sp. stem. The element with the greatest presence in the five materials was potassium, except in A. durangensis bagasse showing calcium. L. aegyptiaca fruit has better characteristics to be used in particleboards with greater mechanical resistance because of its higher holocellulose content. However, Pennisetum sp. (plant, leaves and stem) could be used to make particleboards with high resistance to water absorption.

Three New Alien Taxa for Europe and a Chorological Update on the Alien Vascular Flora of Calabria (Southern Italy)

Knowledge on alien species is needed nowadays to protect natural habitats and prevent ecological damage. The presence of new alien plant species in Italy is increasing every day. Calabria, its southernmost region, is not yet well known with regard to this aspect. Thanks to fieldwork, sampling, and observing many exotic plants in Calabria, here, we report new data on 34 alien taxa. In particular, we found three new taxa for Europe (Cascabela thevetia, Ipomoea setosa subsp. pavonii, and Tecoma stans), three new for Italy (Brugmansia aurea, Narcissus ‘Cotinga’, and Narcissus ‘Erlicheer’), one new one for the Italian Peninsula (Luffa aegyptiaca), and 21 new taxa for Calabria (Allium cepa, Asparagus setaceus, Bassia scoparia, Beta vulgaris subsp. vulgaris, Bidens formosa, Casuarina equisetifolia, Cedrus atlantica, Chlorophytum comosum, Cucurbita maxima subsp. maxima, Dolichandra unguis-cati, Fagopyrum esculentum, Freesia alba, Juglans regia, Kalanchoë delagoënsis, Passiflora caerulea, Portulaca grandiflora, Prunus armeniaca, Prunus dulcis, Solanum tuberosum, Tradescantia sillamontana, and Washingtonia filifera). Furthermore, we provide the first geolocalized record of Araujia sericifera, the confirmation of Oxalis stricta, and propose a change of status for four taxa (Cenchrus setaceus, Salpichroa origanifolia, Sesbania punicea, and Nothoscordum gracile) for Calabria. The updated knowledge on the presence of new alien species in Calabria, in Italy and in Europe could allow for the prevention of other new entries and to eliminate this potential ecological threat to natural habitats.

EX-SITU Characterization of Luffa aegyptaica in Lagos State, Nigeria

Luffa aegyptiaca is a plant of multi-purpose importance whose usefulness cuts across virtually all areas of life. This study has characterized L. aegyptiaca in Lagos state and determined the mineral, proximate, phytochemical as well as the heavy metal accumulation potential. Samples were collected from the 20 Local Government Areas (LGAs) in Lagos state at 2 samples per location. Genetic similarity and intra-specific variation in 40 samples of L. aegyptiaca were determined using 3 Random Amplified Polymorphic DNA (RAPD) primers which yielded a total of 42 markers of which 25 was polymorphic. The maximum number of bands (14) was produced by OPC4 while the minimum (7) were produced by OPAF20. Percentage polymorphisms were 70% (OPAF20), 82.4% (OPC4) and 68.4% (OPC6) with an average value of 73.6%. The result from a genetic diversity study was scored to generate a dendrogram using NTsys (2.0j). Phytochemical, proximate, Mineral and the heavy metal study showed the presence of Flavonoid, Saponin; Carbohydrate, protein; Sodium (Na), Calcium (Ca) and Chromium, Iron, Copper, Zinc, Lead among others. The nutritional composition and the potentials of the RAPD marker in distinguishing intra-specific variation in Luffa aegyptiaca were highlighted in this study.

Catalytic Biotransformations and Inhibition Study of Peroxidase from Luffa aegyptiaca

Background: Present interest in catalytic bioconversions is concerned with 2 major environmental issues. (i) The replacement or substitution of oxidations which involves heavy metal salts and reagents by alternatives using H2O2 as the ecofriendly oxidant. (ii) The prominent issue is the increasing interest in the production of high chemoselectivity, regioselectivity and stereoselectivity of compounds in chemical reactions in order to achieve better byproducts. Keeping these points in view the work on peroxidases have been carried out which fullfills these two goals. Objective: To determine the enzyme activity in the available source to explore its catalytic efficiency in biotransformations of heavy metal compounds. Optimizing the effect of different oxidants for maximum activity of peroxidase and to study the nature of inhibition of peroxidase in presence of different metal ions. Methods: Enzyme extracted in large volume from Luffa aegyptiaca fruit. Peroxidase activity measured by spectrophotometric method. Peroxidase catalyzed rate of reaction was determined spectrophotometerically by making use of guaiacol as the substrate and in presence of H2O2, V2O5, VOSO4, VO(acac)2, (NH4)2(Ce(NO3)6), and (NH4)6Mo7.4H2O monitored at λmax = 470 nm. The haloperoxidase activity were assayed by monitoring the formation of halogen by UV/VIS spectra. The steady state velocity of the enzyme catalysed reaction was measured at different concentrations of metal ions like trivalent (Cr3+ and Al3+), divalent (Ca2+, Mg2+, Cd2+, Zn2+ and Ni2+) and monovalent (Na+ and K+) in the range of 0.0 mM to 100 mM at the fixed enzyme saturating concentration. Graph was plotted to determine the nature of enzyme activity inhibition. Results: Study of rate of reaction by steady state kinetics measurements confirmed peroxidase activity of order of 9.0 U in the fruit extract prepared. The oxidation potential required for the oxidation of guaiacol to tetraguaiacol is 0.575V and the reaction is irreversible. (NH4)2(Ce(NO3)6) and (NH4)6Mo7.4H2O oxidized guaiacol with the rate found to be 0.009 OD/sec in former substituent and the rate of formation of tetraguaiacol was much low in the later substituent found to be 0.003 OD/sec as compared to enzyme with rate 0.01 OD/sec. Enzyme peroxidase was able to oxidize Fe2+ and Mn2+ to Fe3+ and Mn3+ respectively in the reaction mixture. It is found that V2O5 is better oxidizing agent than H2O2 for catalytic oxidation of guaiacol as the substrate. Peroxidases in presence of H2O2 and KBr/KCl/KI act as a viable ecofriendly reagent for the halogenation reaction in organic synthesis. Nature of inhibition by Zn2+ and Ni2+ ions is competitive type. Enzyme activity is inhibited in presence of Cr3+ and Al3+ and the nature of inhibition is uncompetitive type. Conclusion: Luffa aegyptiaca is a better source of peroxidase having 9 U. UV-Visible spectrum analysis indicated that (NH4)2 (Ce(NO3)6 can substitute peroxidase enzyme under optimized conditions.( NH4)2(Ce(NO3)6 act as a cocatalyst by enhancing the activity twice. The enzyme with H2O2 and KBr/KCl/KI is a suitable environmentally suitable reagent for halogenation reaction in organic and inorganic synthesis. The rate of reaction is highest in presence of V2O5 as compared to other vanadium compounds. Thus V2O5 act as better oxidizing agent than H2O2. Chemical technology can be substituted by enzyme technology which should be developed to removal excess and toxic heavy metals. Salinity required for normal functioning of enzyme is 140mM NaCl and 90mM KCl. Enzyme activity enhanced in presence of Ca2+, Mg2+ and Cd2+ while inhibited in presence of Zn2+ and Ni2+. Nature of inhibition by Zn2+ and Ni2+ ions is competitive type. Enzyme activity is inhibited in presence of Cr3+ and Al3+ and the nature of inhibition is uncompetitive type. Extensive studies are needed to understand the mechanism of inhibition of manganese peroxidase activity by metal ions.