Biotechnology-2014 biodegradation performance of phenol by free and alginate entrapped cells of Haloarcula strain D21, an extremely halophilic bacterium isolated from a solar saltern (Ain Salah, Algeria)

Immobilization is a general term that describes many different forms of cell attachment or entrapment. These different forms include encapsulation of cells in a polymer-gel and entrapment in a matrix. The Advantages of these techniques are to reduced possibility of inoculum contamination during storage, transport and application. So, beads are non toxic, biodegradable and non-polluting and can be produced in large quantities, stored for extended periods. Moreover, phenols and phenolic compounds are widely distributed as environmental pollutants due to their common presence in the effluents of many industrial processes, including oil refineries, ceramic plants, coal conversion process, phenolic resins, pharmaceutical and food Industries. The aim of this study was to compare the biodegradation performance of phenol by using free and encapsulated cells of Haloarcula strain D21 isolated from crude oil contaminated saline water collected at Ain Salah in Algeria. Batch experiments were carried out in order to obtain the maximum phenol degradation rates by analyzing the influence of the immobilization in calcium-alginate gel beads on biodegradation performanc

Diversity of microbial communities in production and injection waters of algerian oilfields revealed by 16S rRNA gene amplicon 454 pyrosequencing

The microorganisms inhabiting many petroleum reservoirs are multi-extremophiles capable of surviving in environments with high temperature, pressure and salinity. Their activity influences oil quality and they are an important reservoir of enzymes of industrial interest. To study these microbial assemblages and to assess any modifications that may be caused by industrial practices, the bacterial and archaeal communities in waters from four Algerian oilfields were described and compared. Three different types of samples were analyzed: production waters from flooded wells, production waters from non-flooded wells and injection waters used for flooding (water - bearing formations). Microbial communities of production and injection waters appeared to be significantly different. From a quantitative point of view, injection waters harbored roughly ten times more microbial cells than production waters. Bacteria dominated in injection waters, while Archaea dominated in production waters. Statistical analysis based on the relative abundance and bacterial community composition (BCC) revealed significant differences between production and injection waters at both OTUs 0.03 and phylum level. However, no significant difference was found between production waters from flooded and non-flooded wells, suggesting that most of the microorganisms introduced by the injection waters were unable to survive in the production waters. Furthermore, a Venn diagram generated to compare the BCC of production and injection waters of one flooded well revealed only 4% of shared bacterial OTUs. Phylogenetic analysis of bacterial sequences indicated that Alpha- , Beta- and Gammaproteobacteria were the main classes in most of the water samples. Archaeal sequences were only obtained from production wells and each well had a unique archaeal community composition, mainly belonging to Methanobacteria , Methanomicrobia , Thermoprotei and Halobacteria classes. Many of the bacterial genera retrieved had already been reported as degraders of complex organic molecules and pollutants. Nevertheless, a large number of unclassified bacterial and archaeal sequences were found in the analyzed samples, indicating that subsurface waters in oilfields could harbor new and still-non-described microbial specie

Proliferation and rooting of wild cherry: The influence of cytokinin and auxin types and their concentration

Determination of the most optimal type and concentration of plant growth regulators as medium constituents is one of the most important aspects of successful micro propagation, among other in vitro factors. With the aim of optimization of in vitro multiplication of wild cherry, the effect of the following cytokinins was studied: 6-benzyladenine (BAP), 2-isopentenyl adenine (2iP) and kinetin (Kin) at concentrations of 1, 2, 4 and 8 mg. l-1. Stem segments of seedlings from juvenile and adult materials were disinfected and grown on a Quoirin and Lepoivre (1977) (QL) medium without growth regulators for 4 weeks. Each material responded differently to the tested cytokinins. The use of 6-benzyladenine resulted in the highest percentage of sprouting, the development of shoots and the ratios of multiplication for two materials of Prunus avium L. In the next  experiment, seedlings from the juvenile and adult materials were grown on (MS2/5) medium in the presence of auxins indole-3-butyric acid (IBA), naphtaleneacetic acid (NAA), indole-3-acetic acid (IAA), when compared with concentrations of 0.5, 1, 2, and 4 mg. l-1. For the type of explants and its reactivity with the type and the concentration of auxin, significant differences among explants for root induction were observed. The adult material did not develop roots in any of the auxin and concentration used. In the case of the juvenile material, the IBA was distinguished from the other auxins tested and the highest induction of roots took place in 1mg. l-1. The most significant induction of cal characterizes, especially, the mediums containing the NAA followed by the IAA with concentrations of 2 and 4 mg. l-1, respectively, which block the emergence of the roots partly and decreases the rate of rooting thereafter. The highest average number of roots and the highest average length of roots were obtained with the IBA with 1 mg. l-1.Key words: Wild cherry tree, proliferation, cytokinins, rooting, auxins