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We observed for the first time crown gall symptoms in an orchard of olive trees (Olea europaea) of the variety ‘Chemlali’ – the most widely grown cultivar in Tunisia – in the governorate of Kairouan in central Tunisia. Isolations from symptomatic tissues yielded bacteria that were identified as members of the species complex Agrobacterium tumefaciens using molecular techniques. The isolates were then evaluated for their pathogenicity by inoculating the indicator plant Kalankoë daigremontiana. The virulence of three isolates (O7, O9 and O11) was assessed by PCR amplification of part of the vir region of the Ti-plasmid of Agrobacterium and further confirmed for the O7 isolate by inducing the formation of tumours on ‘Chemlali’ olive seedlings. These results confirm the susceptibility of the olive tree to Agrobacterium tumefaciens, as previously reported by other researchers in Algeria, Jordan, Australia and Argentina. [ABSTRACT FROM AUTHOR]

The analysis of housekeeping recA gene sequences from 138 strains from 13 species or genomic species of Agrobacterium, nine being biovar 1 genomospecies, and the others Agrobacterium larrymoorei, Agrobacterium rubi, Agrobacterium sp. NCPPB 1650, and Agrobacterium vitis and one 'former' Agrobacterium species, Rhizobium rhizogenes, led to the identification of 50 different recA alleles and to a clear delineation of the 14 species or genomospecies entirely consistent with that obtained by amplified fragment length polymorphism (AFLP) analysis. The relevance of a recA sequencing approach for epidemiological analyses was next assessed on agrobacterial Tunisian isolates. All Tunisian isolates were found to belong to the Agrobacterium tumefaciens/biovar 1 species complex by both biochemical tests and rrs sequencing. recA sequence analysis further permitted their unambiguous assignment to A. tumefaciens genomospecies G4, G6, G7, and G8 in total agreement with the results of an AFLP-based analysis. At subspecific level, several Tunisian recA alleles were novel, indicating the power and accuracy of recA-based typing for studies of Agrobacterium spp. [ABSTRACT FROM AUTHOR]

Ripe and overripe olive fruits (cv. Meski, Manzanilla and Picholine) showing circular spots 1 to 10 mm in diameter, slightly depressed and reddish-brown in color, were collected from local markets and orchards located in the regions of Takelsa, Zarzis and Rgueb in Tunisia. Colletotrichum gloeosporioides was isolated from symptomatic fruits and Koch's postulates were fulfilled. This is the first report of Colletotrichum gloeosporioides causing anthracnose of olives in Tunisia. [ABSTRACT FROM AUTHOR]

Olive trees (Olea europaea) cv. Meski having leaves with yellow spots on the upper surface and grey blotches on the lower surface were found in three orchards located in the regions of Takelsa, Testour and Enfidha, central and northern Tunisia. The shoots of the olive trees had also become defoliated indicating a severe attack of a pathogen. Pseudocercospora cladosporioides was isolated from symptomatic leaves and Koch's postulates were fulfilled. This is the first Tunisian report of P. cladosporioides causing Cercospora leaf spot of olive trees. [ABSTRACT FROM AUTHOR]

Since 1927, outbreaks of the leafy gall disease caused by Rhodococcus fascians on annual and perennial herbaceous plants have put the ornamental plant industry at risk. More recently, Pistachio Bushy top syndrome (PBTS), a serious disease emerging in the Western United States, has been declared as a natural disaster by the U.S. Department of Agriculture. Recent developments indicate that the taxonomic position of R. fascians should be re‐evaluated and circumscribed from other members of the genus. Due to the broad host range of this bacterium, economically important crops are in a vulnerable position especially with new members within the genus becoming able to interact synergistically with R. fascians to cause symptom development. The virulence strategies employed by R. fascians and the involvement of cytokinins (CKs) in its pathogenicity have been the subject of much controversy in the last years. Additionally, the detection of virulent strains of R. fascians from symptomatic tissues has been problematic for many researchers. This review focuses on plant–pathogen interaction in context with more recent findings on the association of CKs in virulence of R. fascians. Current knowledge on the worldwide distribution of the pathogen, a historical recap of its discovery and the economic impact of the disease caused by R. fascians are also described here. [ABSTRACT FROM AUTHOR]

SuccFerr (N-[4-ferrocenyl,5-5-bis (4-hydroxyphenyl)-pent-4-enyl]-succinimide) has remarkable antiproliferative effects in vitro, attributed to the formation of a stabilized quinone methide. The present article reports in vivo results for a possible preclinical study. SuccFerr is lipophilic and insoluble in water, so the development of a formulation to obviate this inconvenience was necessary. This was achieved by complexation with randomly methylated cyclodextrins (RAMEßCDs). This supramolecular water-soluble system allowed the in vivo experiments below to proceed. Application of SuccFerr on the glioblastoma cancer cell line U87 indicates that it affects the cellular cycle by inducing a blockade at G0/G1 phase, linked to apoptosis, and another one at the S phase, associated with senescence. Using healthy Fischer rats, we show that both intravenous and subcutaneous SuccFerr: RAMEßCD administration at 5 mg/kg lacks toxic effects on several organs. To reach lethality, doses higher than 200 mg/kg need to be administered. These results prompted us to perform an ectopic in vivo study at 1 mg/kg i.v. ferrocidiphenol SuccFerr using F98 cells xenografted in rats. Halting of cancer progression was observed after six days of injection, associated with an immunological defense response linked to the active principle. These results demonstrate that the properties of the selected ferrocidiphenol SuccFerr transfer successfully to in vivo conditions, leading to interesting therapeutic perspectives based on this chemistry. [ABSTRACT FROM AUTHOR]

Olive mill wastewater (OMW) contains large amounts of organic substances, including phenols, that can have negative environmental consequences when applied to soil. Because of the high concentrations of organic matter and mineral nutrients, OMW holds promise as a fertilizer source for cropping systems. The effects of the addition of 0.5, 1, or 2% OMW to a soil on carbon (C) and nitrogen (N) dynamics and microbiological characteristics of the soil were investigated. Mineral N presented a significant negative correlation with the amount of OMW. The total number of soil bacteria and fungi increased. However, the nitrifying population was sensitive to 2% OMW during the first month. The increase in microbiological activity accelerated the loss of soil organic carbon (SOC). However, the treated soil recovered the SOC, and the total C gains were 2.1, 1.9, and 2.4 g kg−1for the three doses, whereas the SOC loss was 1.1 g kg−1for the control. [ABSTRACT FROM AUTHOR]

Threats of desertification have been projected for the Mediterranean basin under relatively minor warming and drying scenarios. This situation raises the need for mitigation strategies and adaptation of crop production. Crop vulnerability assessment is therefore needed. In Tunisia, olive culture is a major activity. In some cases, olive is the only crop able to grow in local conditions. However, olive production may be among the more vulnerable systems to climate change since perennial crops adapt slowly. No studies have been dedicated to vulnerability evaluation of olive production. Here, the vulnerability of Tunisian olive trees to drought was assessed under extremely low precipitation levels, of 50% of normal precipitation, from 1999 to 2002. The impact of drought was quantified using a severity scale with three levels. A map of the impact of drought on olive trees was constructed for all Tunisian olive groves. We found that the number of wilting olive trees in 2002 was 7.8 millions of about 60 millions trees. A correlation was observed between olive tree affection by drought and olive orchard age. Thus, under the same drought conditions, senescent orchards were less resistant to drought than young ones. Locally, data showed that compact soils and soils containing more than 1% gypsum were not suitable for olive growth under drought. [ABSTRACT FROM AUTHOR]

Olive mill wastewater (OMW) is a rich source of antifungal agents and has a merit as alternative to synthetic fungicides. To develop disease control agents against Botrytis cinerea, a hydroxytyrosol-rich (29.27% weight:dry weight) olive mill wastewater (HROMW) and a hydroxytyrosol-rich (52.67% weight:dry weight) extract (HRE) were prepared from fresh OMW using hydrolysis and post-hydrolysis purification processes. The HROMW and HRE showed strong fungicidal activity against B. cinerea with minimal fungicidal concentrations (MFCs) of 14.36-28.72 and 28.72-57.44 mg l (dry weight), respectively. According to EN 1275: 1997 standard method, HROMW and HRE at 1.25% (dry weight:volume) showed powerful disinfectant properties resulting in a reduction in the viability of B. cinerea spores by >4 log units after 30 min of contact time. The HROMW or HRE foliar spray treatments, of the B. cinerea inoculated tomato plants, resulted in disease control percentage of 95 and 91%, respectively, whereas 70% was conferred by benomyl treatment. Although, HRE possessed a similar disease severity reduction than HROMW, it showed great advantage by fortifying plants and by improving their growth and healthy aspect. Indeed, HRE-treated plants showed significantly better: (i) plant height (146.2 and 130.5%), (ii) average stem diameter (135% and 110%), (iii) leaf number (163.6 and 128.5%), and (iv) leaf colour (chlorophyll a content) (144.4 and 103%) than benomyl-treated and non-treated plants, respectively. This study revealed that HRE offers a natural and effective extract to control grey mould. [ABSTRACT FROM AUTHOR]

Abstract: Hydroxytyrosol-rich olive mill wastewater (HROMW) and hydroxytyrosol-rich composition (HRC) were prepared from olive mill wastewater using hydrolysis and post-hydrolysis purification processes. The HROMW and HRC showed powerful bactericidal and fungicidal activities against phytopathogens, and their minimal inhibition concentrations for fungi and bacteria were 7.18–57.4mgl−1 and 7.18–14.4mgl−1, respectively. After 5min of contact time, the disinfectant properties of the HROMW and HRC added at concentrations of 1.25% (dw/v) allowed for a reduction in bacterial viability by greater than 5 log units. However, a higher concentration of 1.5–3% (dw/v) or a longer contact time of 30min were needed to achieve values for fungal viability reduction that were higher than the 4 log units recommended by EN 1275 [EN 1275 (1997a). Chemical disinfectants and antiseptics. Basic fungicidial activity. Test method and requirements (phase 1)]. HROMW and HRC were less effective with the most ubiquitous fungi, Fusarium spp., which needed 10% dw/v. The addition of HRC at 10% (dw/v) showed that the composition was a potent exogenous enhancer of growth that stimulated the seedling vigour of tomato and muskmelon, according to the conventional agronomic parameters for seed vigour. Compared to the control, the germination percentage, shoot weight, shoot height, and root length were all significantly enhanced in the HRC-treated seed plants. HRC was found to have effective disinfectant properties against seed-borne diseases. In treated seeds, the composition had significant effects on the control of damping-off disease groups at the pre-germination stage. HRC was also equally effective in the control of root rot diseases caused by Fusarium sambucinum and Alternaria solani as well as of wilts and even bacterial seed-borne pathogens. HROMW was also found to be as effective as HRC in terms of its efficacy against the three seed-borne diseases mentioned above. [Copyright &y& Elsevier]

Olive anthracnose caused by Colletotrichum species causes dramatic losses of fruit yield and oil quality worldwide. A total of 185 Colletotrichum isolates obtained from olives and other hosts showing anthracnose symptoms in Spain and other olive-growing countries over the world were characterized. Colony and conidial morphology, benomyl-sensitive, and casein-hydrolysis activity were recorded. Multilocus alignments of ITS, TUB2, ACT, CHS-1, HIS3, and/or GAPDH were conducted for their molecular identification. The pathogenicity of the most representative Colletotrichum species was tested to olive fruits and to other hosts, such as almonds, apples, oleander, sweet oranges, and strawberries. In general, the phenotypic characters recorded were not useful to identify all species, although they allowed the separation of some species or species complexes. ITS and TUB2 were enough to infer Colletotrichum species within C. acutatum and C. boninense complexes, whereas ITS, TUB2, ACT, CHS-1, HIS-3, and GADPH regions were necessary to discriminate within the C. gloesporioides complex. Twelve Colletotrichum species belonging to C. acutatum, C. boninense, and C. gloeosporioides complexes were identified, with C. godetiae being dominant in Spain, Italy, Greece, and Tunisia, C. nymphaeae in Portugal, and C. fioriniae in California. The highest diversity with eight Colletotrichum spp. was found in Australia. Significant differences in virulence to olives were observed between isolates depending on the Colletotrichum species and host origin. When other hosts were inoculated, most of the Colletotrichum isolates tested were pathogenic in all the hosts evaluated, except for C. siamense to apple and sweet orange fruits, and C. godetiae to oleander leaves. [ABSTRACT FROM AUTHOR]

The reduction of the use chemical pesticides in agriculture is gaining importance as an objective of decision-makers in both politics and economics. Consequently, the development of technically efficient and economically affordable alternatives as, e.g., biological control agents or practices is highly solicited. Crown gall disease of dicotyledonous plants is caused by ubiquitous soil borne pathogenic bacteria of the Agrobacterium tumefaciens species complex, that comprises the species Agrobacterium fabrum and represents a globally relevant plant protection problem. Within the framework of a screening program for bacterial Agrobacterium antagonists a total of 14 strains were isolated from Tunisian soil samples and assayed for antagonistic activity against pathogenic agrobacteria. One particularly promising isolate, termed strain MBY2, was studied more in depth. Using a Multilocus Sequence Analysis (MLSA) approach, the isolate was assigned to the taxonomic species Bacillus velezensis. Strain MBY2 was shown to display antagonistic effects against the pathogenic A. fabrum strain C58 in vitro and to significantly decrease pathogen populations under sterile and non-sterile soil conditions as well as in the rhizosphere of maize and, to a lower extent, tomato plants. Moreover, the ability of B. velezensis MBY2 to reduce C58-induced gall development has been demonstrated in vivo on stems of tomato and almond plants. The present study describes B. velezensis MBY2 as a newly discovered strain holding potential as a biological agent for crown gall disease management. [ABSTRACT FROM AUTHOR]

The purpose of this study was to isolate and identify Rhodococcus spp. strains from almond and pistachio rootstocks and trees in Tunisia. Twenty-eight strains were identified through 16S rDNA and vicA genes amplification and sequencing. Pea bioassay was performed to determine the pathogenicity of the strains. Representative 16S rDNA and vicA sequences of eight strains from pistachio and seven strains from almond were closely related (>98% similarity) to Rhodococcus spp. accessions in GenBank. Phylogenetic analysis based on 16S rDNA sequences revealed that the yellow-colored strains clustered with phytopathogenic Rhodococcusfascians. The red and orange-colored strains were separated into a different group with R. kroppenstedtii and R. corynebacteiroides isolates. Eleven strains affected the pea seedlings' growth and exhibited different levels of virulence. The number of shoots was significantly higher in seedlings inoculated with four Rhodococcus strains, whereas the other three strains caused up to 80% of plant height reduction and reduced root secondary growth compared to non-inoculated pea seedlings. These strains, most of which are epiphytes from asymptomatic hosts, showed strong pathogenicity during pea bioassay and were established endophytically in pea tissues. Ten att and five fas genes were detected in four strains and may represent a novel model of plant pathogenic Rhodococcus virulence. The results of our survey showed that Rhodococcus is present but not prevalent in all visited orchards of almond and pistachio rootstocks and trees. Our surveys complemented the investments being made on ornamental species in Tunisia and unveiled the presence of undocumented plant-associated Rhodococcus spp. on economically important crops. [ABSTRACT FROM AUTHOR]

Olive mill wastewaters and olive cake are effluents generated during olive oil production process. They represent a major disposal and potentially severe pollution problem for the industry, also promising source of substances of high value. The aim of this study is the valorization of olive mill wastes (OMWW, olive cake, olive twigs and leaves) to produce enzymes with high industrial and biotechnological potential, by the solidstate fermentation technique (SSF), from isolated fungi present in olive mill wastewater and olive cake. A total of 47 strains were isolated and purified from these two residues. The metabolic potential of isolated strains was study by testing the hydrolytic enzymes activities of lipase, protease, amylase, cellulase, invertase, phytase and tannase on agar plate media containing different substrate. The monitoring of SSF has shown that the metabolic activity of these strains is extremely rapid using this technique. Our fungi collection contains a diversity of strains capable to producing a variety of enzymes of biotechnological interest. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The article offers information on the plant disease caused by the phytopathogenic isolates of Rhodococcus fascians, a Gram-positive bacterium. It discusses that the bacteria cause disease on numerous plants by inducing fasciation and leafy galls. It mentions that the bacteria altered plant morphology resulting from these infections cause serious economic losses to ornamental industries.

Verticillium dahliae is one of the most important soil pathogens, causing verticillium wilt. It is well known that the use of chemical products against this pathogen is not without side effects on the environment. In this regard, the present study was aimed to search for antagonistic rhizobacteria as an alternative of biological control against this causal agent. A total of 162 isolates were screened for their antagonistic activity according to the "double layer" and the "well diffusion" methods. Three of them (RS11, SF82 and ZO4), were subsequently selected as biological control agent (BCAs) according to their efficiency and were identified by 16S rRNA sequencing and Biolog microplate GEN III as Bacillus spp. Using 10 different lipopeptide gene primers, PCR reactions only revealed the involvement of genes responsible for iturins (ituA, ituD, ituC), bacillomycin (bmyA) and Bacilysin (bacA / B-F, bacA / B-R) biosynthesis. The Plant Growth Promoting Rhizobacteria traits [enzymatic activities, phytohormones production] of the three BCAs were also studied in vitro then on pepper plant (Capsicum annuum L.), indicating that Bacillus subtilis ZO4 was the most effective, enhancing leaf, stem and root growth comparing to the control. [ABSTRACT FROM AUTHOR]

Objective: We synthesized new tamoxifen derivatives as anticancer drug candidates and elaborated on convection‐enhanced delivery (CED) as a strategy for delivery. Methods: To overcome the issue of their poor solubility, these ferrocenyl‐tamoxifen derivatives were esterified and encapsulated into different nanocarriers, that is lipid (LNC) and polymeric nanocapsules (PNL‐NC). We describe the chemistry, the encapsulation and the physicochemical characterization of these formulations. Key findings: Starting compounds [phthalimido‐ferrocidiphenol and succinimido‐ferrocidiphenol], esterified prodrugs and their nanocapsules formulations were characterized. These drug candidates displayed a strong in vitro activity against breast and glioblastoma cancer cells. The ester prodrugs were toxic for glioblastoma cells (IC50 = 9.2 × 10−2 μm and 6.7 × 10−2 μm, respectively). The IC50 values for breast cancer cells were higher for these compounds. The encapsulation of the esterified compounds in LNCs (≈50 nm) or PCL‐NCs (≈300 nm) did not prevent their efficacy on glioblastoma cells. These anticancer effects were due to both blockade in the S‐phase of the cell cycle and apoptosis. Moreover, the tamoxifen derivatives‐loaded nanocapsules induced no toxicity for healthy astrocytes and showed no haemolytic properties. Loaded Lipid Nanocapsules (LNCs) presented interesting profiles for the optimal delivery of active compounds. Conclusions: Phthalimido‐ and Succinimido‐esters represent an innovative approach to treat cancers with cerebral localizations such as glioblastoma or brain metastases from breast cancers. [ABSTRACT FROM AUTHOR]

The low diversification of rootstocks can be a problem in reducing the adaptation of pistachio to the Tunisian climatic and soil conditions. Nowadays, the most used rootstock is Pistacia vera; however, the autochthonous Pistacia atlantica could be a good alternative. The aim of this work was to study the effect of two different rootstocks Pistacia vera and Pistacia atlantica on the quality and functionality of two pistachio cultivars (the local variety "Mateur" and the Syrian one "Achoury"). The different parameters studied were: morphological (size, weight), chemical (minerals and fatty acids) and functional (total phenolic content, and antioxidant activity: ABTS+, DPPH•, and FRAP). The pistachios are a good source of minerals (especially Ca and K 19.9 and 9.8 g kg-1, respectively, and Fe 54.5 mg kg-1), polyunsaturated fatty acids (oleic and linoleic acids), and phenolic compounds (16.0 g GAE kg-1). The combination P. atlantica and variety "Mateur" led to proper values of tree yield, nut dehiscence, morphology (length and width), and oleic acid content. Thus, it can be concluded that the use of the local rootstock P. atlantica led to promising results and can be a good option due to its higher adaptation to the local climatic and soil conditions. [ABSTRACT FROM AUTHOR]

Agrobacterium fabrum is one of the eleven Agrobacterium spp. complex species that has been observed to carry a Ti plasmid and induce crown gall, a disease causing significant damage to economically important perennial agricultural crops. Members of this species complex, including A. fabrum, are morphologically indistinguishable from one another on culture media and are known to grow together in soil and within host galls. Consequently, the tracking of this species in its natural environment requires a cautious approach to tagging strains without altering any of their ecologically important traits. A gentamicin resistant cassette (aacCl) was inserted, by homologous recombination, into a non-coding region of the A. fabrum C58 chromosome between the genes atull82 and atull83. The resultant strain did not show any significant in vitro growth differences compared to the wild-type strain, and the marker was stable in rich medium, both with and without selective pressure. The mutant/marked strain was indistinguishable from the parental strain for ability to induce galls, grow in bulk soil and colonize the rhizosphere of tomato plants. Easy, precise, safe and stable tagging of the A. fabrum C58 genome facilitates environmental population surveys by either simple selection or direct detection by PCR. This methodology provides understanding of the ecology of this species complex as an integral part of managing the soil microbiota for improved crown gall management. [ABSTRACT FROM AUTHOR]

Over two consecutive seasons, 16 olive orchards with trees exhibiting dieback symptoms on branches were surveyed in southern Spain. The six dominant fungal species recovered were characterized by means of phenotypic observations, DNA analysis (by sequencing of the internal transcribed spacer, (3-tubulin, and large subunit nuclear ribosomal DNA regions), and pathogenicity tests. Additionally, three isolates collected from Tunisian olive trees showing similar dieback symptoms, one isolate of Colletotrichum godetiae, and a reference isolates of Neofusicoccum mediterraneum were included. The resistance of the 11 most important table cultivars to N. mediterraneum and Botryosphaeria dothidea, the causal agent of "escudete" (small shield) of fruit, was studied by the inoculation of branches and immature fruit, respectively. The species Cytospora pruinosa, N. mediterraneum, Nothophoma quercina, Comoclathris incompta, and Diaporthe sp. were identified. Only N. mediterraneum and C. incompta were able to induce the typical dieback symptoms and cankers that affected the development of the plants. The species N. mediterraneum was the most virulent among the evaluated species, although differences in virulence among its isolates were observed. The remaining fungal species were weakly pathogenic to nonpathogenic on plants. According to resistance tests, 'Gordal Sevillana' and 'Manzanilla Cacerena' were the most susceptible to branch dieback caused by N. mediterraneum. Furthermore, the fruit of 'Alorena de Atarfe' and 'Manzanilla de Sevilla' were the most susceptible to B. dothidea. Knowledge of the etiology and cultivar resistance of these diseases will help to establish better control measures. [ABSTRACT FROM AUTHOR]

Several ferrocenyl analogues of tamoxifen have already showed strong antiproliferative activity in experimental glioma models. Nevertheless, these compounds are very poorly soluble in water and an adapted formulation is needed. In this work, we have tailored and optimized methylated cyclodextrin soluble complexes of phthalimido–ferrocidiphenol for the first time. The complexes were characterized, and the optimized formulation was tested for in vitro efficacy and cell proliferation assays on U87, human glioblastoma cancer cells. Molecular modeling can provide accurate information about the inclusion process. The inclusion of all the moieties at the same time ( i.e. , ferrocene, phthalimidylpropyl, 2 phenols) is not possible due to the steric hindrance of the 1:4 system. The 1:3 systems are possible but do not seem very relevant. However, various 1:2 and 1:1 complexes are mostly present in aqueous solutions. Some experiments have confirmed our hypothesis. First, interactions between the phenol, phthalimidylpropyl and ferrocenyl groups have been observed in our NMR experiments. Second, the inclusion of phthalimidylpropyl was detected by UV–vis spectrophotometry with an apparent 1:1 interaction, which was observed through the Benesi–Hildebrand method. The complex is readily soluble in water and keeps its pharmacological activity against U87 tumor cells (IC 50 = 0.028 ± 0.007 μM vs. 0.018 ± 0.003 μM for PhtFerr). [ABSTRACT FROM AUTHOR]

Bacillus subtilis strain 14B was used to produce a novel antimicrobial peptide (bacteriocin) called Bac 14B. Pure bacteriocin was obtained after heat and acidic treatments (80°C and pH 4), precipitation by ammonium sulfate, and chromatography on Sephadex G-50 and Mono Q Sepharose columns. Based on MALDI-TOF mass spectrometry analysis, purified Bac 14B is a monomer protein with a molecular mass of 20110.13 Da. N-terminal sequencing allowed for the straightforward identification of its first 12 residues, which were of a pure bacteriocin. It also revealed that this bacteriocin contained a unique sequence, namely M-L-K-A-N-L-Q-N-P-L-N-A, suggesting the identification of a novel compound. Bac 14B was stable for 1 h at temperatures up to 80°C and pH of 4 ∼ 8. It also proved sensitive to various proteases, which demonstrated its protein nature. Bac 14B displayed a bacteriolytical mode of action and a broad range of inhibitory spectra toward Gram-positive and -negative pathogens. Interestingly, based on conventional agronomic seed vigor parameters, the application of Bac 14B (500 activity units/mL) to various crops revealed that this bacteriocin was a potent exogenous enhancer of growth that stimulated the seedling vigor of tomatoes and muskmelons. Compared to those of the control, the germination percentage, shoot weight, shoot height, and root length were all significantly enhanced in Bac 14B-treated plant seeds. Bac 14B also exhibited effective disinfectant properties against a wide range of seedborne diseases and significant effects on the control of damping off diseases, particularly at the pregermination stage. It also proved to be effective against root rot diseases caused by Alternaria solani and other bacterial seedborne pathogens such as wilt diseases. The findings indicate that Bac 14B is the first B. subtilis-produced bacteriocin ever reported to exhibit such promising biological properties. [ABSTRACT FROM AUTHOR]

Olive trees (cv. Chemlali) showing typical symptoms of wilt and dieback were collected from several areas in Tunisia. Visual diagnostic, isolation and microscopic observations identified the causal pathogen as Verticillium dahliae. The pathotype was determined using specific primers pairs for D (defoliating) and ND (non-defolitating) . Artificial inoculation of olive plants resulted in typical wilting with defoliation, proving that the isolate tested was pathogenic on olive, and this isolate belongs to the D pathotype. This is the first report of the defoliating pathotype causing wilting disease on olive in Tunisia. [ABSTRACT FROM AUTHOR]

Abstract: Some ferrocene compounds, such as tamoxifen derivatives hydroxyferrocifen 1 and ferrociphenol 2, show strong antiproliferative activity on hormone-dependent and hormone-independent breast cancer cells. In order to evaluate their antimicrobial activity, they were tested, together with their purely organic analogs, on the bacteria Pseudomonas aeruginosa and Staphylococcus aureus and the fungus Candida albicans. It has been found that the compounds bearing alkylamino chains are active, and in these cases the antimicrobial activity increases for compounds bearing two amino chains. These dialkyamino compounds are equally as active as doxycycline on P. aeruginosa and S. aureus but superior to it on C. albicans. The results show that there are no general correlation between the antitumoral activity and the bactericidal and fungicidal activities of these compounds. The ferrocene derivatives and their organic analogs have similar activity on bacteria and fungus. This bactericidal and fungicidal behaviour is a novel area of activity for these entities. [Copyright &y& Elsevier]

Rheological and thermal properties of xanthan produced by Xanthomonas campestris from date by-products (DBP-xanthan) and commercial xanthan were determined. DBP-xanthan gave solutions with lower apparent viscosity than commercial xanthan. However, DBP-xanthan solutions were more stable to temperature changes and ionic strength than commercial xanthan. Gradual increase of storage modulus (G′ ) as function of frequency was observed for the two polysaccharides. On the other hand, loss modulus (G″ ) remained constant for DBP-xanthan and an increase was observed for commercial xanthan. Granulometric profile indicates that DPB-xanthan particle size was lower than commercial xanthan. Differential scanning calorimetry showed that the melting temperatures (T m) and enthalpy (ΔH m) of DBP-xanthan were higher than those of commercial xanthan. These properties of DBP-xanthan are quite rare among xanthan described in the literature and give this new gum great potential for use in the field of bioindustries as thickening and stabilizing agents. PRACTICAL APPLICATIONS Xanthan gum from date by-products (DBP-xanthan) was recently produced in our laboratory. No work has been undertaken to study the rheological properties of this polysaccharide to date. Rheological and some physicals properties were compared to those of commercial xanthan. This could promote industrial use of DBPs as low-cost natural source for xanthan gum production. [ABSTRACT FROM AUTHOR]