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11.
Ahmed Barkia Ali Bougatef Rim Nasri Emna Fetoui Rafik Balti Moncef Nasri 《Fish physiology and biochemistry》2010,36(4):893-902
Trypsin from the viscera of Bogue (Boops boops) was purified to homogeneity by precipitation with ammonium sulphate, Sephadex G-100 gel filtration and Mono Q-Sepharose
anion exchange chromatography, with an 8.5-fold increase in specific activity and 36% recovery. The molecular weight of the
purified enzyme was estimated to be 23 kDa by SDS–PAGE and size exclusion chromatography. The purified trypsin appeared as
a single band on native-PAGE and zymography staining. The purified enzyme showed esterase-specific activity on N-α-benzoyl-l-arginine ethyl ester (BAEE) and amidase activity on N-α-benzoyl-dl-arginine-p-nitroanilide (BAPNA). The optimum pH and temperature for the enzyme activity, after 10 min incubation, were pH 9.0 and 55°C,
respectively, using BAPNA as a substrate. The trypsin kinetic constants K
m and k
cat on BAPNA were 0.13 mM and 1.56 s−1, respectively, while the catalytic efficiency k
cat
/K
m was 12 s−1 mM−1. Biochemical characterisation of B. boops trypsin showed that this enzyme can be used as a possible biotechnological tool in the fish processing and food industries. 相似文献
12.
Emna Abdellatif Monika Kałużna Patrizia Ferrante Marco Scortichini Bochra Bahri Jaap D. Janse Johan van Vaerenberg Steve Baeyen Piotr Sobiczewski Ali Rhouma 《Plant pathology》2020,69(8):1414-1425
Citrus blast and black pit caused by Pseudomonas syringae pv. syringae (Pss) is the only bacterial disease reported in Tunisian Citrus orchards. The phylogenetic relationship between Pss strains was studied based on multilocus sequence analysis (MLSA), using partial sequences of housekeeping genes rpoD, rpoB, gyrB, cts, and pfk for 14 representative Pss Citrus strains, including the reference strain LMG5496. The MLSA revealed that the studied Tunisian Citrus strains are closely related to LMG5496 and cluster in phylogroup 02. Based on the cts gene, the majority of Citrus strains clustered in clades “a” and “b”. However, five strains were placed in a newly defined clade “g”. We describe the presence of six different type III secreted effectors (T3SEs). These were found with frequencies of 100% for the effector hopAN1 and the helper hrpK1, 65% for hopT1-2, and 14% for hopN1, hopR1, and hopQ1-2. Investigation of copper resistance showed that 67% of our Pss Citrus strains from Tunisia are resistant to copper sulphate in vitro, and the copper resistance genes copABCDR were detected in 23% of the strains. Our results present new data concerning the genetic diversity and phylogeny, presence of T3SEs, and copper resistance within the Pss populations that affect Citrus in Tunisia. 相似文献
13.
Zouheyr Benbrahim Abdellatif Zerizer Louis Denaud Remy Marchal 《Wood material science & engineering》2020,15(4):241-249
ABSTRACT Veneer checking is a common enough occurrence in woodworking. It appears as cracks in the veneer and generally following the grain. Their appearance and the variation of their depth and frequencies have tremendous impact on their utilization. Finding a means of identifying and characterizing the veneer checks is an important ongoing challenge. An automated device, named SMOF, was developed in LABOMAP (Arts et Metiers – France) and achieves this task. By using the SMOF device, the lathe checks occurred in veneers of two species: zeen oak (Quercus canariensis Willd.) and afares oak (Quercus afares Pomel) were detected, automatically imaged and then, the depth and intervals of checks measured. The results were described by statistical distributions that exhibited abnormalities, such as skewness and kurtosis, which were assessed by mode analysis. It has been established that hot soaking temperature (from 60°C to 90°C) reduce slightly the cutting forces for both species, no produce significant heart checks within the loose side of veneers. However, low soaking temperature (from 50°C to 65°C) allow avoiding deeper lathe checking, producing shallower ones acceptable for veneer production. 相似文献
14.
Salma Wasti Arafet Manaa Hajer Mimouni Anissa Nsairi Medyouni Ibtissem Emna Gharbi 《Journal of plant nutrition》2017,40(5):673-684
The aim of this study was to investigate the impact of application of calcium silicate and salinity singly, on plant growth and nutritional behavior and photosynthetic pigments of tomato. Application of sodium chloride (NaCl) induced significant reduction in plant development and growth parameters. Salt stress also led to an accumulation of sodium (Na+) and a decrease in potassium (K+) concentration. Reduction of chlorophyll and carotenoid in leaves were amongst other symptoms in salt-affected plants in 2 cultivars. Rio Grande was qualified as salt sensitive and Moneymaker as the salt tolerant genotype. Application of Silicon (Si) only improved plant behaviour as compared to control. Furthermore, Si induced ameliorative effects on the growth potential of NaCl stressed plants. This Si-ameliorative effect on plant varied depending on the considered cultivar and Si concentration. Based on these results, application of calcium silicate was suggested as an alternative way to ameliorate the harmful effects of salinity on tomato. 相似文献
15.
Ibtissem Hamrouni Sellami Emna Maamouri Thouraya Chahed Wissem Aidi Wannes Mohamed Elyes Kchouk Brahim Marzouk 《Industrial Crops and Products》2009,30(3):395-402
The variation in the content and composition of Origanum majorana L. essential oil has been studied. Plant material has been harvested at four phenological stages (early vegetative, late vegetative, budding and full-flowering). Essential oil yield varied from 0.04 to 0.09% reached during the full-flowering stage. Analysis of the essential oils by GC and GC/MS revealed the presence of 38 components represented mainly by oxygenated monoterpenes (64.01–71.4%), monoterpene hydrocarbons (21.73–29.92%) and sesquiterpene hydrocarbons (1.47–4.05%). The main components were terpinen-4-ol (29.13–32.57%), cis-sabinene hydrate (19.9–29.27%), trans-sabinene hydrate (3.5–11.61%), γ-terpinene (2.11–8.20%), bornyl acetate (1.52–2.94%) and linalool (1.05–1.39%). On the other hand, phenolic contents varied from 2.706 to 6.834 mg/g of dry weight obtained during the later vegetative stage. RP-HPLC analysis of the methanolic extract of O. majorana L. dried aerial parts showed the predominance of phenolic acids during the early vegetative stage whereas flavonoids predominate during the other stages of growth. The main phenolic acids identified were trans-2-hydroxycinnamic, rosmarinic, vanillic, chlorogenic, gallic and cinnamic whereas the main flavonoids were amentoflavone, apigenin, quercetin, luteolin, coumarin and rutin. Results obtained showed that later vegetative stage is characterized by the highest contents of bioactive compounds and therefore it could be considered as the best stage for harvesting marjoram plants. 相似文献
16.
Kamal Foud Abdellatif Yehia Abdallah Khidr 《Journal of Crop Science and Biotechnology》2010,13(3):139-145
Genetic diversity of four new yellow single crosses, five new yellow three-way crosses, and five yellow inbred lines of maize
(Zea mays L.) was studied using different molecular (SSR, ISSR, and RAPD) and biochemical markers (seed storage protein content). All
markers were able to clearly separate the inbred lines in one cluster from the different types of hybrids. The correlation
among the different types of molecular markers was moderately high according to the Mantel’s test (e.g. 0.67 between SSR and
ISSR, 0.42 between SSR and RAPD, and 0.65 between ISSR and RAPD), indicating that the three techniques are efficient for evaluating
genetic diversity in the maize genotypes. The correlation of biochemical markers (seed storage protein SDS-PAGE) with SSR,
ISSR, and RAPD markers was 0.61, 0.74, and 0.48, respectively. It can be concluded that both molecular and biochemical markers
are efficient to study the genetic diversity in maize. Among the different types of molecular markers, SSR is a more accurate
marker-type because of its co-dominance and stability of results. It can also be said that biochemical and molecular markers
are positively correlated and the correlation ranged between moderate to high. This could suggest using both marker types,
separately or together, for genetic diversity studies in maize. 相似文献
17.
El mustafa Ait Chattou Najem Abounahel Jawad Kassila Yassine Ouagajjou Abderrahmane Abouhala Mohamed Idhalla Abdellatif Moukrim 《Aquaculture Research》2019,50(3):736-747
There is a great interest in establishing mussel farming in Dakhla bay. Selection of suitable sites is more meaningful only if a reliable culture method at proposed site is included. We compared two different culture methods, longline and pole, over 1 year (June 2016 to June 2017). Growth indicators for Perna perna (size and weight growth rates, frequency distributions and estimating growth curves) were analysed from seeding to harvest. The results highlighted the influence of culture method on growth rates of mussels (p < 0.05). At harvest, individuals reared on longline presented higher growth rates and consequently reached greater weight and length values than those reared on pole. Mussels reared at the longline grew 73.2 mm and gained 53.5 g WL (live weight) and 3.3 g Wt (tissue dry weight) after 12 months of cultivation. However, mussels cultured at the pole gained only 52.3 mm, 26.7 g WL and 1.6 g Wt. Aerial exposure of mussels at low tides could explain this reduced performance on pole compared with longline. Size frequency distributions at harvest fitted bimodal distribution in both cultures due to an asymmetric competition among individuals. Effect of density started in both treatments after 7 months of culture when mussels reached 60–70 mm, implying an increment of their food and space requirements. To prevent overcrowding, the initial density should have been reduced through “thinning‐out.” The longline method exhibited high‐performance growth and hence is highly recommended for cultivation of P. perna in Dakhla bay. 相似文献
18.
Maher Gtari Lorenzo Brusetti Diego Mora Abdellatif Boudabous 《Soil biology & biochemistry》2007,39(1):372-377
Elaeagnus compatible Frankia isolates from Tunisian soil have been previously clustered with Frankia, colonizing Elaeagnaceae and Rhamnaceae in two different phylogenetic subgroups, while strain BMG5.6 was described as a new lineage closely related to Frankia and Micromonospora genera. In this study we further assess the diversity of captured Frankia and the relationship with BMG5.6-like actinobacteria, by using nifH gene sequences. Using PCR-RFLP screening on DNA extracted from lobe nodules, additional microsymbionts sharing BMG5.6 features have been detected proving a widespread occurrence of these actinobacteria in Elaeagnus root nodules. Neighbour-Joining trees of Frankia nifH sequences were consistent with previously published 16S rRNA and GlnII phylogenetic trees. Although four main clades could be discerned, actinobacterial strain BMG5.6 was clustered with Frankia strains isolated from Elaeagnus. The present study underscored the emanation of new diazotrophic taxon isolated from actinorhizal nodules occupying intermediate taxonomic position between Frankia and Micromonospora. Moreover, its aberrant position in nifH phylogeny should open network investigations on the natural history of nitrogen-fixing gene among actinobacteria. 相似文献
19.
Khalid Majourhat Youssef Jabbar Abdellatif Hafidi Pedro Martínez-Gómez 《Annals of Forest Science》2008,65(8):805-805
20.
Corn zein was cross-linked with glutaraldehyde (GDA) using glacial acetic acid (HAc) as catalyst. The objectives are to evaluate the swelling characteristics of GDA cross-linked zein gels in water, ethanol, and their combinations. Similar formulations, upon solvent evaporation, form films. The mechanical properties of the films are compared to compression molded tensile bars from GDA melt-processed zein as a second objective. Chemistry of the cross-linking reaction was based on the aldehyde binding characteristics defined by use of fluorescence spectroscopy; sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) to demonstrate the cross-linking reaction; FTIR to observe absorption differences of the cross-linked product; differential scanning calorimetry, dynamic mechanical analysis and thermogravimetric analysis to assess thermal properties; and the use of Instron Universal Testing Machine to evaluate mechanical properties. A reaction mechanism for acid catalyzed GDA cross-linking of zein is proposed. Thermal and mechanical properties of tensile bars cut from either film or formed by compression molding were similar, where both showed increased tensile strengths, ductility and stiffness when compared with unmodified controls. Samples that were reacted with 8% GDA by weight based on weight of zein from either process retained their integrity when tensile bars from each were subjected to boiling water for 10 min or soaking in either water or HAc for 24 h. The melt-processed, cross-linked zein is a more environmentally friendly method that would eliminate the need for HAc recovery. 相似文献