Abdellatif Haggoud

Cellulolytic potential of fungi in wood degradation from an old house at the Medina of Fez

During the history of civilizations, advanced wood decay results from exposure to various agents for long periods of time. Bio-deterioration, under the influence of living organisms like fungi, can cause massive damage to historical monuments. In this work, we found that fungi participating in wood degradation share a single strategy for degrading wood polymers by secreting enzymes that break down the main constituents of wood such as cellulose, hemicellulose and lignin. WhilePenicillium commune, Penicillium granulatum andPenicillium chrysogenum showed the highest cellulase productivity and are therefore the most destructive for timber, other fungal species participate also in this biodegradation includingPenicillium crustosum, Penicillium expansum Cladosporium cladosporioides and a cellulotic specieThielavia hyalocarpa that we describe here for the first time.

Isolation and identification of a staphylococal strain with an anti-mycobacterial activity and study of it’s mode of action

The resistance of mycobacteria to the clinical applied antibiotics poses a serious problem to deal with the infections they cause. So, the search for new antibiotics active against these bacteria becomes urgent. We report here the isolation from a Moroccan biotope of a bacterial strain secreting an active substance of protein nature that inhibits the growth of several mycobacterial species (Mycobacterium smegmatis; M. aurum A+;M. vaccae; M. bovis BCG andM. kansasii). PCR amplification and DNA sequecing of the 16S ribosomal RNA gene allowed the identification of this strain asStaphylococcus haemolyticus. Moreover, the substance produced by this strain was able to lyse the wall ofM. smegmatis and to extract its genomic DNA indicating that it acts probably, like others anti-mycobacterial antibiotics, on this envelope. The identification and characterisation of the active substance would open the way for further technological and therapeutic investigations.

In vitro and intracellular antimycobacterial activity of a Bacillus pumilus strain

Despite the declaration of tuberculosis (TB) as a global emergency by the world health organization (WHO) about 20 years ago, the worldwide problem of this disease has worsened due to increased drug resistance of tuberculosis bacilli and acquired immune deficiency syndrome (AIDS) pandemic. Consequently, fight against multidrug and extensively drug-resistant TB is a high priority for public health and research. The present work describes the isolation of a

Yeast strains from the endogenous microflora of the olive fliesBactrocera oleae larvae which could degrade the olive oil mill wastewaters polyphenols

Worldwide, wastewaters constitute a major environmental pollutant. They are very toxic against a wide range of plants and soil microorganisms. Their toxicity is due to the presence of compounds such as polyphenols. In this study, we have isolated yeast strains from the endogenous microflora of the olive fliesBactrocera oleae larvae that were capable of degrading the olive oil mill wastewater polyphenols. The results obtained showed the presence, in the digestive tract of the larvae, of yeast strains resisting to polyphenols. Two resistant strains were isolated and have shown variable capacity of polyphenols degradation that could reach up to 72%. The two isolated strains were identified by two methods: conventional technique and molecular method associating PCR amplification and DNA sequencing of the 5.8S ribosomal RNA gene. Both techniques showed that the two isolated strains corresponded to theCandida diddensiae specie. Related to its capacity to degrade polyphenols, this specie would be a potential candidate for wastewater treatment and environmental protection.

Isolation and identification of Bacillus strains with antimycobacterial activity

Tuberculosis is the principal cause of death worldwide due to an infectious disease. The resurgence of tuberculosis, followed by the increase in prevalence of infections caused by nontuberculous mycobacteria (NTM), as well as the multi-drug resistance of mycobacteria to the majority of currently available antibiotics, have encouraged research for new antimycobacterial agents. Soil and water samples from different Moroccan biotopes, have led to the isolation of four bacterial strains ( M, R, G and S), showing an inhibitory effect on mycobacterial growth. This effect was shown to be due to secreted substances in the growth medium. From subsequent analysis it was concluded that these strains produced different active substances. Sequencing of the 16S rRNA showed that these isolates belong to the genus Bacillus . The active substance from isolate M, showed the more important inhibitory effect on mycobacterial growth. It is precipitated with ammonium sulfate and lost all activity when treated with Proteinase K, revealing its protein nature.

Activité antimycobactérienne des extraits de deux espècesmarocaines du genre Cistus

RésuméCistus albidus et Cistus salvifolius, deux espèces de la famille des Cistacées, sont répandues dans le bassin méditerranéen et sont dotées de propriétés thérapeutiques. Dans ce travail, l’activité antimycobactérienne de ces deux espèces est évaluée. L’incorporation des extraits aqueux et éthanolique dans le milieu gélosé, la méthode de disque et la détermination des concentrations minimales inhibitrices (CMI) ont montré que les extraits des deux plantes possèdent un effet antimycobactérien. Les fractions responsables de l’activité observée ont été identifiées après fractionnement des extraits par chromatographie sur couche mince (CCM) et couverture de la plaque chromatographique avec une culture liquide de Mycobacterium smegmatis. Les tests phytochimiques effectués ont montré que les molécules responsables de l’activité antimycobactérienne sont des polyphénols pour les deux plantes.AbstractCistus albidus and Cistus salvifolius, two species of the family Cistaceae, are common in the Mediterranean Basin. They have therapeutic properties. In this study, the antimycobacterial activity of these two species is evaluated. The incorporation of aqueous and ethanol extracts in the agar medium, disk diffusion method and minimal inhibitory concentration assay have shown that extracts of both plants have an antimycobacterial effect. The fractions responsible for the observed activity were identified after fractionation of extracts by thin layer chromatography (TLC) and coverage of the chromatographic plate with a liquid culture of Mycobacterium smegmatis. The phytochemical tests carried out showed that the molecules responsible for the antimycobacterial activity are polyphenols for both plants.

Isolation and identification of a Staphylococcus warneri strain with anti-mycobacterial activity

Tuberculosis is the principal cause of death from infection in the world. The resurgence of tuberculosis and the increase in mycobacterial infections, as well as multidrug-resistance of mycobacteria to available antibiotics, has incentivized research on new antimycobacterial agents. Therefore, research based on water and soil samples from the Moroccan biotopes, has led to the isolation of a bacterial strain capable of inhibiting mycobacterial growth ( Mycobacterium smegmatis and Mycobacterium aurum A + ). The effect was due to an active substance secreted into the culture medium. Sequencing of the 16S rRNA gene identified the strain as belonging to the species Staphylococcus warneri. The active substance precipitated using ammonium sulfate, maintained its inhibitory properties, which were lost when treated with proteinase K. These results indicated that the active substance was protein. Study of the activity of the metabolite revealed its effect on M. smegmatis cell wall, facilitating genomic DNA extraction. Keywords: Tuberculosis, mycobacteria, anti-mycobacterial agents, Staphylococcus warneri , DNA extraction. African Journal of Biotechnology Vol. 12(42), pp. 6119