Biology subjects

Zitouni, A.

Publications and source records attributed to Zitouni, A..

3 recordsLinked to original sources

bioRxiv2023

Delving into the Bacillus cereus group biosynthetic gene clusters cosmos: a comparative-genomics-based classification framework

BackgroundIn this study, the Bacillus sp. strain BH32 (a plant-beneficial bacterial endophyte) and its closest non-type Bacillus cereus group strains were used to study the organization, conservation, and diversity of biosynthetic gene clusters (BGCs) among this group to propose a classification framework of gene cluster families (GCFs) among this intricate group. A dataset consisting of 17 genomes was used in this study. Genomes were annotated using PROKKA ver.1.14.5. The web tool antiSMASH ver. 5.1.2 was used to predict the BGCs profiles of each strain, with a total number of 198 BGCs. The comparison was made quantitatively based on a BGCs counts matrix comprising all the compared genomes and visualized using the Morpheus tool. The constitution, distribution, and evolutionary relationships of the detected BGCs were further analyzed using a manual approach based on a BLASTp analysis (using BRIG ver. 0.95); a phylogenetic analysis of the concatenated BGCs sequences to highlight the evolutionary relationships; and the conservation, distribution and the genomic co-linearity of the studied BGCs using Mauve aligner ver. 2.4.0. Finally, the BIG-SCAPE/CORASON automated pipeline was used as a complementary strategy to investigate the gene cluster families (GCFs) among the B. cereus group. ResultsBased on the manual approach, we identified BGCs conserved across the studied strains with very low variation and interesting singletons BGCs. Moreover, we highlighted the presence of two major BGCs synteny blocks (named "synteny block A" and "synteny block B"), each composed of conserved homologous BGCs among the B. cereus group. For the automatic approach, we identified 23 families among the different BGCs classes of the B. cereus group, named using a rational basis. The proposed manual and automatic approaches proved to be in harmony and complete each other, for the study of BGCs among the selected genomes. ConclusionUltimately, we propose a framework for an expanding classification of the B. cereus group BGCs, based on a set of reference BGCs reported in this work.

genomics↗

bioRxiv2022

Alleviation of salt stress in winter wheat by Pantoea spp. endophytes isolated from spontaneous desert plants of the Sahara

To develop bio-fertilizers for salt stress mitigation in winter wheat, 5 Pantoea spp. strains isolated from spontaneous plants of the Algerian Sahara were selected and identified based on the 16S rRNA gene, and distinguished at "strain" level by the IGS sequences. A plant test (greenhouse condition, non-sterile substrate) showed their effectiveness in promoting the growth of winter wheat cv. Gold Korn, under normal and saline conditions. An improvement of shoot length (no stress: up to +37.34% for Pantoea sp. BS27; salt stress at 200 mM: up to +32.95% for Pantoea sp. BS27) and dry weight (no stress: up to +23.89% for Pantoea sp. OT18; salt stress at 100 mM: up to +56.42 % for Pantoea sp. ME3; salt stress at 200 mM: up to 39.18% for Pantoea sp. OT18) was recorded. We suggest the Pantoea spp. strains ME3, OT37, and OT18 as promising inocula for yield improvement in salt-impacted soils.

microbiology↗

bioRxiv2022

The effect of different treatment durations with indole-3-acetic acid (IAA)-producing endophytic Bacillus spp. on tomato 'Aicha' under saline conditions

This study aimed to investigate the effect of indole-3-acetic acid (IAA)-producing endophytes from saline environments on survival and growth of tomato under salt stress, using different treatment times. Twenty-five endophytic bacteria were isolated from halophytes (Atriplex halimus L., Tamarix aphylla L.) issued from saline regions (Algeria). Five strains were selected based on tolerance to NaCl. A polyphasic taxonomic study was conducted. The selected strains were assigned to the Bacillus cereus group. Quantification of IAA production was done by high-performance liquid chromatography (HPLC). An in vitro test of growth promotion/protection of tomato Aicha was conducted under saline conditions (50 mM, 75 mM, 100 mM, and 125 mM), for different durations of seed biopriming (1h, 3h, and 12h). Endophytes led to a significant amelioration of salt stress in tomato Aicha at all salinity levels, depending on treatment times, indicating the necessity of optimizing this crucial factor.

microbiology↗