Oxidative stress,ceruloplasmin and neopterin biomarkers in dromedary camels with clinical endometritis

The purpose of this study is to investigate the role of some oxidative stress (OS), ceruloplasmin (Cp), and neopterin (NPT) as diagnostic biomarkers for dromedary camels endometritis as well as to explore the impact of ceftiofur treatment on endometritis. Camels were categorized into two groups; healthy control group (n = 20) and endometritis group (n = 60). She-camels with clinical signs of endometritis (CE) received 6.6 mg/kg BW of ceftiofur (i/m). On days 7, and 14, she-camels were evaluated and clinical cure or failure to cure was determined. The comparison of the groups for OS demonstrated that endometritis caused an increase in serum malondialdehyde (sMDA), Cp, and NPT levels (P<0.05), but decreased serum levels of superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) (P<0.05). The most prevalent pathogens involved in the etiology of CE are Arcanobacterium pyogenes, Streptococcus pyogenes, and Staphylococcus aureus. All examined biomarkers demonstrated a high degree of recognition between CE camel and healthy controls (the area under the curve (AUC) was 95.9 for NPT). A higher proportion of camels with CE that were treated with ceftiofur (90%, P<0.0001) showed clinical cure by the first dose, while 10% required a second dose. In conclusion, CE causes increased oxidative reactions and decreased antioxidant defense competence. Subsequently, the alteration in that balance that was represented by the biomarkers of OS could be beneficial for clinical practice and basic clinical research. Additionally, all trials demonstrated the efficacy of ceftiofur for the treatment of CE in she-camel.     

A phosphate-stimulated NAD(P)+-dependent glyceraldehyde-3-phosphate dehydrogenase in Bacillus cereus

Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), a key enzyme of central carbon metabolism, was studied in a Bacillus cereus strain isolated from the phosphate layer from Morocco. Enzymatic assays with cell extracts demonstrated that when grown on Luria-Bertani (LB) medium, B. cereus contains a major NAD+-dependent GAPDH activity and only traces of NADP+-dependent activity, but in cells grown on Pi-supplemented LB medium a strong increase of the NADP+-dependent activity, that became predominant, occurs concurrently with a GAPDH protein increase. Our results show that B. cereus possesses two GAPDH activities, namely NAD+- and NADP+-dependent, catalyzed by two enzymes with distinct coenzyme specificity and different phosphate regulation patterns. The finding of a phosphate-stimulated NADP+-dependent GAPDH in B. cereus indicates that this bacterium can modulate its primary carbon metabolism according to phosphate availability.     

Isolation,Classification and Antagonistic Properties of Alkalitolerant Actinobacteria from Algerian Saharan Soils

Abstract

The Sahara, one of the most extreme environments on Earth, constitutes an unexplored source of alkalitolerant actinobacteria. In this work, we studied the diversity of alkalitolerant actinobacteria in various soils collected from different regions of the Algerian Sahara. A total of 29 alkalitolerant actinobacterial strains were isolated by using a complex agar medium. The diversity of these actinobacteria was evaluated using a polyphasic approach, which included morphological, chemotaxonomic, physiological (numerical taxonomy) and 16S rRNA gene analyses. The isolates which were assigned to the genus Nocardiopsis, shared relatively low 16S rRNA gene sequences similarities compared to closely related species suggesting that they belonged to putatively new species. All of the strains were tested for antibiotic activity against a broad range of microorganisms and screened for genes encoding polyketide synthases and non-ribosomal peptide synthetases and found to have the potential to produce secondary metabolites. Consequently, the study supports the view that extreme environments contain many novel actinobacteria, which represent an unexplored source for the discovery of biologically active compounds.     

Characterisation of Pythium paroecandrum and its antagonism towards Botrytis cinerea, the causative agent of grey mould disease of grape

Pythium paroecandrum (B-30), an oomycete, was isolated from soil samples taken from a wheat field in Genlis in the Burgundy region of France and was found to check the growth and development of Botrytis cinerea, a serious grapevine pathogen. The oomycete is a fast-growing organism, living on vegetable debris, and can be recognised by its catenulate hyphal swellings, catenulate oogonia, and monoclinous antheridia. When grown together with B. cinerea, the causal agent of the grey mould disease of the grapevine, P. paroecandrum shows a pronounced antagonism and suppresses its growth and its aptitude to provoke the grey mould symptoms. Morphological features of this oomycete, its antagonism to B. cinerea, the sequences of the internal transcribed spacer region of its nuclear ribosomal DNA, and its comparison with related species are discussed in this article.     

Novel major bacterial candidate division within a municipal anaerobic sludge digester

In a previous study, we analyzed the molecular diversity of Planctomycetales by PCR amplification and sequencing of 16S rRNA clone libraries generated from a municipal wastewater plant, using planctomycete-specific and universal primer sets (R. Chouari, D. Le Paslier, P. Daegelen, P. Ginestet, J. Weissenbach, and A. Sghir, Appl. Environ. Microbiol. 69:7354-7363, 2003). Only a small fraction (4%) of the 16S rRNA gene sequences of the digester clone library corresponded to the Planctomycetales division. Importantly, 85.9% of the digester clone sequences are grouped into two different clusters named WWE1 (81.4% of the sequences) and WWE2 (4.5%) and are distantly affiliated with unidentified bacterial sequences retrieved from a methanogenic reactor community and from a termite gut, respectively. In phylogenetic analysis using 16S rRNA gene sequence representatives of the main phylogenetic bacterial divisions, the two clusters are monophyletic, branch apart from each other, and are distantly related to Planctomycetales and other bacterial divisions. A novel candidate division is proposed for WWE1, while the WWE2 cluster strongly affiliates with the recently proposed Lentisphearae phylum. We designed and validated a 16S rRNA probe targeting WWE1 16S rRNA sequences by both fluorescent in situ hybridization (FISH) and dot blot hybridization (DBH). Results of FISH analysis show that WWE1 representative microorganisms are rods or filamentous shaped, while DBH shows that WWE1 accounts for 12% of the total bacterial rRNA within the anaerobic digester. The remaining 16S rRNA gene sequences are affiliated with Verrucomicrobia or recently described candidate divisions with no known pure culture representatives, such as OD1, BRC1, or NBL-UPA2, making up less than 3.5% of the clone library, respectively. This inventory expands the known diversity of the latter bacterial division-level lineages.     

Electronic structure and bonding of the dinuclear metal M<Subscript>2</Subscript>(CO)<Subscript>10</Subscript> decacarbonyls: applications of natural orbitals for chemical valence

The nature of the chemical metal–metal bond in M₂(CO)₁₀ (M?=?Mn, Re, Tc) dinuclear decacarbonyls complexes was investigated for the first time using the natural orbital chemical valence (NOCV) approach combined with the extended transition state (ETS) for energy decomposition analysis (EDA). The optimized geometries carried out at different levels of theory BP86, BLYP, BLYPD and BP86D, showed that the latter method, i.e., BP86D, led to the best agreement with X-ray experimental measurements. The BP86D/TZP results revealed that the computed covalent contribution to the metal–metal bond are 60.5%, 54.1% and 52.0% for Mn–Mn, Re–Re and Tc–Tc, respectively. The computed total interaction energies resulting from attractive terms (ΔE _orb and ΔE _eles), correspond well to experimental predictions, based on bond lengths and energy interaction analysis for the studied complexes.     

Actinopolyspora saharensis sp. nov., a novel halophilic actinomycete isolated from a Saharan soil of Algeria

A novel halophilic actinomycete, strain H32^T, was isolated from a Saharan soil sample collected in El-Oued province, south Algeria. The isolate was characterized by means of polyphasic taxonomy. Optimal growth was determined to occur at 28–32 °C, pH 6.0–7.0 and in the presence of 15–25 % (w/v) NaCl. The strain was observed to produce abundant aerial mycelium, which formed long chains of rod-shaped spores at maturity, and fragmented substrate mycelium. The cell wall was determined to contain meso-diaminopimelic acid and the characteristic whole-cell sugars were arabinose and galactose. The predominant menaquinones were found to be MK-10(H₄) and MK-9(H₄). The predominant cellular fatty acids were determined to be anteiso C_17:0, iso-C_15:0 and iso-C_16:0. The diagnostic phospholipid detected was phosphatidylcholine. Phylogenetic analyses based on the 16S rRNA gene sequence showed that this strain formed a distinct phyletic line within the radiation of the genus Actinopolyspora. The 16S rRNA gene sequence similarity indicated that strain H32^T was most closely related to ‘Actinopolyspora algeriensis’ DSM 45476^T (98.8 %) and Actinopolyspora halophila DSM 43834^T (98.5 %). Furthermore, the result of DNA–DNA hybridization between strain H32^T and the type strains ‘A. algeriensis’ DSM 45476^T, A. halophila DSM 43834^T and Actinopolyspora mortivallis DSM 44261^T demonstrated that this isolate represents a different genomic species in the genus Actinopolyspora. Moreover, the physiological and biochemical data allowed the differentiation of strain H32^T from its closest phylogenetic neighbours. Therefore, it is proposed that strain H32^T represents a novel species of the genus Actinopolyspora, for which the name Actinopolyspora saharensis sp. nov. is proposed. The type strain is H32^T (=DSM 45459^T=CCUG 62966^T).     

Prokaryotic diversity of a Tunisian multipond solar saltern

16S rRNA gene clone libraries were separately constructed from three ponds with different salt concentrations, M2 (15%), TS38 (25%) and S5 (32%), located within a multipond solar saltern of Sfax. The 16S rRNA genes from 216 bacterial clones and 156 archaeal clones were sequenced and phylogenetically analyzed. 44 operational taxonomic units (OTUs) were generated for Bacteria and 67 for Archaea. Phylogenetic groups within the bacterial domain were restricted to Bacteroidetes and Proteobacteria, with the exception that one cyanobacterial OTU was found in the TS38 pond. 85.7, 26.6 and 25.0% of the bacterial OTUs from M2, TS38 and S5 ponds, respectively, are novel. All archaeal 16S rRNA gene sequences were exclusively affiliated with Euryarchaeota. 75.0, 60.0 and 66.7% of the OTUs from, respectively, M2, TS38 and S5 ponds are novel. The result showed that the Tunisian multipond solar saltern harbored novel prokaryotic diversity that has never been reported before for solar salterns. In addition, diversity measurement indicated a decrease of bacterial diversity and an increase of archaeal diversity with rising salinity gradient, which was in agreement with the previous observation for thalassohaline systems. Comparative analysis showed that prokaryotic diversity of Tunisian saltern was higher than that of other salterns previously studied. A. Sghir and E. Ammar have equally contributed to this work.     

Ethanol production from olive cake biomass substrate

The inexpensive production of sugars from lignocellulose is an essential step for the use of biomass to produce fuel ethanol. Olive cake is an abundant by-product of the olive oil industry and represents a potentially significant lignocellulosic source for bioethanol production in the Mediterranean basin. Furthermore, converting olive cake to ethanol could add further value to olive production. In the present study, olive cake was evaluated as a feedstock for ethanol production. To this end, the lignocellulosic component of the olive cake was dilute-acid pretreated at a 13.5% olive-cake loading with 1.75% (w/v) sulfuric acid and heating at 160°C for 10 min. This was followed by chemical elimination of fermentation inhibitors. Soluble sugars resulting from the pretreatment process were fermented using E. coli FBR5, a strain engineered to selectively produce ethanol. 8.1 g of ethanol/L was obtained from hydrolysates containing 18.1 g of soluble sugars. Increasing the pretreatment temperature to 180°C resulted in failed fermentations, presumably due to inhibitory by-products released during pretreatment.