Effect of harvesting and post-harvest practices on the microbiological quality of dates fruits (Phoenix dactylifera L.)

In Morocco, many dates varieties are produced and marketed, including local and imported dates, mainly Deglet Nour variety. The present study aimed to evaluate microbiological contamination on ten varieties of dates from four different production areas in Morocco, from the date market of Marrakech, and from the imported Deglet Nour variety, and to show effects of harvesting and post-harvest practices on the microbiological quality of dates. Physicochemical data presented that the pH of studied varieties varies between 5 and 6 and water activity from 0.28 to 0.62. Microbiological analysis displayed that samples from Tata region presented the highest microbial spoilage with Total Viable Counts (TVC) ranging from 4.2 log CFU.g-1 to 2.6 log CFU.g-1 and yeast/moulds reaching 2.99 log CFU.g-1. Deglet Nour dates imported from Algeria, and Tunisia were less contaminated (TVC <1.0 log CFU.g-1, yeasts/moulds <1.0 log CFU.g-1). Coliforms, Bacillus sp. and Staphylococcus were not found in any sample. Results revealed that some varieties produced and marketed in Morocco are affected by microbial spoilage, which can be assigned to uncontrolled dates processes of harvesting and post-harvesting practices

Effect of pre-harvest practices on physical and colorimetric characteristics of date fruit (cv. ‘Aziza Bouzid’) in Figuig oasis

Dates represent a very important energy source that contains a wide range of functional, nutritional, bioactive, and aromatic components. Dates characteristics have been widely studied but none has been conducted on the pre-harvest factors responsible for the quality variation. The aim of this study is to evaluate the effect of pre-harvest practices on physical and colorimetric characteristics. The analyses were conducted on twelve samples of ‘Aziza Bouzid’ cultivar and collected at Tmar stage from Figuig oasis. Results obtained for physical parameters show a significant variation between different samples. Weight of ‘Aziza Bouzid’ varied from 5.44 g to 9.04 g. Geometric mean diameter and Porosity varied from 13.08 mm to 17.01 mm and 31.88 % to 42.3 % respectively for ‘Aziza Bouzid’. Highest Chroma and hue values registered for ‘Aziza Bouzid’ were 38.14 and 83.22 and the lowest were 21.1 and 67.15. This study contributes to develop good agricultural practices, help improve the quality and increase the quantity of Moroccan date production

<i>Colutea arborescens</i> is nodulated by diverse rhizobia in Eastern Morocco

Eighteen isolates of rhizobia isolated from root nodules of Colutea arborescens (Bladder senna) grown in different soils of the eastern area of Morocco were characterized by phenotypic and genomic analyses. All the isolates characterized were fast growers. This is may be due to the isolation procedures used. The phenotypic, symbiotic and cultural characteristics analyzed allowed the description of a wide physiological diversity among tested isolates. The results obtained suggest that the phenotype of these rhizobia might have convergent evolved to adapt the local conditions. The genetic characterization consisted in an analysis of the rep-PCR Wngerprints and the PCR-based RFLP of the 16S rDNA patterns. The 16S rDNA of six isolates representing the main ribotypes obtained by the PCR-based RFLP was sequenced. A large diversity was observed among these rhizobia, and they were classified as different species of the genera Rhizobium, Sinorhizobium and Mesorhizobium. The nodC gene was also sequenced, and the results confirmed the three lineages corresponding to the three genera. The results of the sequencing of nodC and 16S rDNA genes suggest that the nodulation genes and chromosome might have co-evolved among these bacteria

Definition of a novel symbiovar (sv. retamae) within Bradyrhizobium retamae sp. nov., nodulating Retama sphaerocarpa and Retama monosperma

In this paper we analyze through a polyphasic approach several Bradyrhizobium strains isolated in Spain and Morocco from root nodules of Retama sphaerocarpa and Retama monosperma. All the strains have identical 16S rRNA genes and their closest relative species is Bradyrhizobium lablabi CCBAU 23086T, with 99.41% identity with respect to the strain Ro19T. Despite the closeness of the 16S rRNA genes, the housekeeping genes recA, atpD and glnII were divergent in Ro19T and B. lablabi CCBAU 23086T, with identity values of 95.71%, 93.75% and 93.11%, respectively. These differences were congruent with DNA-DNA hybridization analysis that revealed an average of 35% relatedness between the novel species and B. lablabi CCBAU 23086T. Also, differential phenotypic characteristics of the new species were found with respect to the already described species of Bradyrhizobium. Based on the genotypic and phenotypic data obtained in this study, we propose to classify the group of strains isolated from R. sphaerocarpa and R. monosperma as a novel species named Bradyrhizobium retamae sp. nov. (type strain Ro19T=LMG 27393T=CECT 8261T). The analysis of symbiotic genes revealed that some of these strains constitute a new symbiovar within genus Bradyrhizobium for which we propose the name >retamae>, that mainly contains nodulating strains isolated from Retama species in different continents.The authors acknowledge funding from ERDF-cofinanced grant P09RNM4746 from Consejería de Economía, Innovación y Ciencia (Junta de Andalucía), Junta de Castilla y León, Junta de Castilla-La Mancha and Comunidad de Madrid (Regional Spanish Governments), MINECO and MCI (Central Spanish Government). BRD was supported by contract of Junta de Comunidades de Castilla La Mancha (Project ref. POII10-0211-5015). MHRB is recipient of a JAE-Doc researcher contract from CSIC. The authors thank S. Fajardo for excellent technical assistance and Dr. J.P. Euzeby for his help with the naming of the novel species

Definition of B. retamae sp. nov., nodulating Retama sphaerocarpa and Retama monosperma in oriental Morocco and Southern Spain

Trabajo presentado en 4th Moroccan Microbiology Association Congress (MMA). 16th African Association for Biological Nitrogen Fixation (AABNF), celebrado en Rabat (Marruecos), del 2 al 7 de noviembre de 201