BIOKEMIJSKA ISTRAŽIVANJA TUNISKIH AUTOHTONIH EKOTIPOVA BISRNOG PROSA (Pennisetum glaucum (L.) R. Br)

Pearl millet (Pennisetum glaucum (L.) R. Br) is a staple food in many developing countries and constitutes the major source of essential nutrients in semi-arid and arid regions of Africa and India. The knowledge about the nutrient content of autochthonous pearl millet ecotypes is scarce. In this study, biochemical analysis of six Tunisian pearl millet ecotypes has been investigated. Results provide evidence of differences in polyphenols content, antioxidant potential and polyphenol oxidase (PPO) activity among the studied ecotypes. These three parameters were found significantly correlated. Moreover, some ecotypes were shown to be potentially quite important sources of health promoting antioxidants. The studied biochemical properties could be used as criteria of selection for a specific food application especially the integration of this cereal in diverse industrial nutritional products.Biserno proso (Pennisetum glaucum (L.) R. Br) osnovna je hrana u mnogim zemljama u razvoju i predstavlja najveći izvor osnovnih hranidbenih sastojaka u polupustinjskim i pustinjskim regijama Afrike i Indije. Znanje o nutricionističkom sastavu autohtonih ekotipova bisernog prosa je površno. U ovoj studiji obrađena je biokemijska analiza šest tuniskih ekotipova bisernog prosa. Rezultati dokazuju razlike u količinama polifenola, antioksidans potencijala i polifenol oksidacijske (PPO) aktivnosti unutar proučavanih ekotipova. Utvrđeno je da su ova tri parametra međusobno povezana. Štoviše, neki ekotipovi mogli bi se iskoristiti kao kriterij selekcije za određenu primjenu u prehrani, pogotovo pri korištenju ove žitarice u raznim prehrambenim proizvodima

Amplification of the active site of BnLIP3 gene of Brassica napus L. during germination

Lipases are useful enzymes that are responsible for the hydrolysis of triacylglycerides and play an important role in plant growth. In this study, we report a rapid molecular method to amplify a partial sequence of the lipase class 3 family designated BnLIP3 gene of Brassica napus L. in order to follow its expression and analyze its role during seed germination. Therefore, we conceived PCR homologous primers to amplify the active site encoding region of the BnLIP3 family genes. Subsequently, to sequence determination of the 582 bp fragment, we deduced BnLIP3 specific primers for a nested RTPCR application. The deduced 194 amino acid sequence (Genbank 1160264) was found to share 85% of identity with lipase from Arabidopsis thaliana class 3 family. The GxSxG consensus motif near the catalytic triad at the active serine site was also identified. The peptidic sequence showed little homology with mammalian and microbial lipases. RT-PCR analysis indicated that BnLIP3 gene was expressed during B. napus seed germination.Keywords: Brassica napus L., GxSxG lipase, germination, BnLIP3, RT-PCR.African Journal of Biotechnology Vol. 12(25), pp. 3905-391

Microbial Consortia as Plant Biostimulants: Definition, Concept, Categories, and Regulation.

peer reviewedMicrobial consortia include cellulolytic bacteria, fungi, yeasts, and microbial-based biofilms which can be found in, or constituents of, food products, soils, wastewater, etc. flourishing in nature. The characterization, design, and management of these consortia are feasible, and their application in diverse fields, such as agriculture, is under research. During the last decades, considerable attention has been paid to microbial consortia as plant bio stimulants. They are an ecological alternative for sustainable agriculture and a win-win strategy to grow valuable plants without releasing fertilizers and/or pesticides into the environment. Plant biostimulants are natural preparations, of a diverse class of substances and/or micro-organisms, which positively affect plant growth conditions, stimulate natural processes, improve yield and chemical composition, and increase tolerance to biotic and abiotic stress. The purpose of this chapter is to provide an up-to-date overview of microbial consortia used as plant biostimulants. Aiming to describe the emerging definitions of plant bio stimulants, their concept, the functional categories, and their potential application as a significant tool for modern eco-friend agriculture. The chapter focuses also on reporting the regulatory framework and the current market situation of plant bio stimulants, as well as their advances in research

Cell Viability Effects and Antioxidant and Antimicrobial Activities of Tunisian Date Syrup (Rub El Tamer) Polyphenolic Extracts

The aqueous−acetone polyphenolic extract of the traditionally derived date syrup, known as “Rub El Tamer”, was analyzed using RP-HPLC-DAD and ESI-MS. The phenolic content of the extract was 394.53 ± 1.13 mg per 100 g of syrup with caffeoylsinapylquinic acid as the most abundant compound (72.23%). The extract exhibited strong antioxidant activities as evaluated using the ABTS (2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)), DPPH (2,2-diphenyl-1-picrylhydrazyl) and FRAP (ferric reducing antioxidant power) methods. The extract antimicrobial potential against a range of microorganism strains showed that Staphylococcus aureus, Staphylococcus epidermidis, and Bacillus cereus were the most sensitive bacteria with MBC in the range of 0.5−0.05 mg/mL. Furthermore, in the presence of the syrup extract (8.18−131 μg/mL), the Human SH-SY5Y neuroblastoma and the 3T3 fibroblast cell lines showed dissimilar reduction of viability suggesting a higher cytotoxic effect against tumorigenic cells. Our results provide new insights into date syrup characterization which should stimulate further studies of this hot desert resource

Polyphenolic Extract of Barbary-Fig (Opuntia ficus-indica) Syrup: RP–HPLC–ESI–MS Analysis and Determination of Antioxidant, Antimicrobial and Cancer-Cells Cytotoxic Potentials

The traditionally derived syrup of Opuntia ficus-indica fruit is commonly used in homemade confectionery. Herein, the aqueous-acetone extract prepared from the Tunisian O. ficus-indica syrup was investigated. The qualitatively and quantitatively polyphenolic content was analysed using reversed-phase high-performance liquid chromatography–diode array detection (RP-HPLC–DAD) coupled to electrospray ionisation–mass spectrometry (ESI–MS). The extract contained 19.95 ± 2.01 mg phenolics per gram of fresh starting material with isorhamnetin 3-O-robinobioside as the major compound (22.76%). The syrup extract showed strong antioxidant potentials as assessed by both ABTS and DPPH functional methods. It exhibited effective antimicrobial activity, particularly against Staphylococcus aureus and Staphylococcus epidermidis with a minimal bactericide concentration (MBC) of 1.3 mg phenolics/ml. Furthermore, at final concentrations in the range of 41.38–186.25 μg polyphenols/ml, the extract decreased human SH-SY5Y neuroblastoma and 3T3 fibroblast in vitro cell viability in a dose- and time-dependent manner compared to non-treated control cells. The observed effects were significantly (P < 0.05) high against cancer lines. Extract concentrations higher than 106.43 μg/ml reduced cancer cells viability to 50–60% 1–3 h post-treatment. Further in vivo insight studies should emphasise and validate the herein obtained results

Quince peel polyphenolic extract blocks human colon adenocarcinoma LS174 cell growth and potentiates 5-fluorouracil efficacy

Additional file: Figure S1. The effect of combination of Peph phenolic compounds on proliferation of LS174 cells compared to total Peph extract. Human colon adenocarcinoma LS174 cells were treated for 72 h with different combinations (A. 3 combinations, B. 4 combinations, C. 5 combinations) of Peph phenolic compounds. All compounds where tested at equivalent concentrations to that present in 5 Οg/ml of the total peel polyphenolic extract. Cell viability was determined by MTT assay

Amplification of the active site of BnLIP3 gene of Brassica napus L. during germination

Lipases are useful enzymes that are responsible for the hydrolysis of triacylglycerides and play an important role in plant growth. In this study, we report a rapid molecular method to amplify a partial sequence of the lipase class 3 family designated BnLIP3 gene of Brassica napus L. in order to follow its expression and analyze its role during seed germination. Therefore, we conceived PCR homologous primers to amplify the active site encoding region of the BnLIP3 family genes. Subsequently, to sequence determination of the 582 bp fragment, we deduced BnLIP3 specific primers for a nested RTPCR application. The deduced 194 amino acid sequence (Genbank 1160264) was found to share 85% of identity with lipase from Arabidopsis thaliana class 3 family. The GxSxG consensus motif near the catalytic triad at the active serine site was also identified. The peptidic sequence showed little homology with mammalian and microbial lipases. RT-PCR analysis indicated that BnLIP3 gene was expressed during B. napus seed germination.Glaied Ghram, I.; Belguith, H.; Messaoudi, A.; Fattouch, S.; Vicente Meana, Ó.; Ben Hamida, J. (2013). Amplification of the active site of BnLIP3 gene of Brassica napus L. during germination. African Journal of Biotechnology. 12(25):3905-3913. doi:10.5897/AJB12.2861S39053913122

Etiology of apple tree dieback in tunisia and abiotic factors associated with the disease

[EN] An apple tree dieback syndrome causing severe tree losses was observed in the main apple producing regions in Tunisia from 2006-2008. This work aimed at identification of the causal agents and the factors that promote apple tree dieback. The causal agents of the syndrome included the following: Phytophthora and Pythium species: Phytophthora parasitica and Phytophthora inundata, Pythium sp., Pythium indigoferae, Pythium irregulare, Pythium rostratifingens, Pythium sterilum and Pythium undulatum. Molecular techniques confirmed the results of the morphological identification. Pathogenicity assays showed the involvement of these pathogens in apple tree dieback. Soil salinity was also shown to be an important factor of disease severity in this study.Souli, M.; Abad Campos, P.; Pérez Sierra, AM.; Fattouch, S.; Armengol Fortí, J.; Boughalleb-M'hamdi, N. (2014). Etiology of apple tree dieback in tunisia and abiotic factors associated with the disease. African Journal of Microbiology Research. 8(23):2272-2281. doi:10.5897/AJMR2013.6141S2272228182