3 research outputs found
Identification and Antibiosis of a Novel Actinomycete Strain RAF-11 Isolated From Iraqi Soil.
A total of 35 actinomycetes strains were isolated from and around Baghdad, Iraq, at a depth of 5-10 m, by serial dilution agar plating method
Microbial community drivers of PK/NRP gene diversity in selected global soils
Background
The emergence of antibiotic-resistant pathogens has created an urgent need for novel antimicrobial treatments. Advances in next-generation sequencing have opened new frontiers for discovery programmes for natural products allowing the exploitation of a larger fraction of the microbial community. Polyketide (PK) and non-ribosomal pepetide (NRP) natural products have been reported to be related to compounds with antimicrobial and anticancer activities. We report here a new culture-independent approach to explore bacterial biosynthetic diversity and determine bacterial phyla in the microbial community associated with PK and NRP diversity in selected soils.
Results
Through amplicon sequencing, we explored the microbial diversity (16S rRNA gene) of 13 soils from Antarctica, Africa, Europe and a Caribbean island and correlated this with the amplicon diversity of the adenylation (A) and ketosynthase (KS) domains within functional genes coding for non-ribosomal peptide synthetases (NRPSs) and polyketide synthases (PKSs), which are involved in the production of NRP and PK, respectively. Mantel and Procrustes correlation analyses with microbial taxonomic data identified not only the well-studied phyla Actinobacteria and Proteobacteria, but also, interestingly, the less biotechnologically exploited phyla Verrucomicrobia and Bacteroidetes, as potential sources harbouring diverse A and KS domains. Some soils, notably that from Antarctica, provided evidence of endemic diversity, whilst others, such as those from Europe, clustered together. In particular, the majority of the domain reads from Antarctica remained unmatched to known sequences suggesting they could encode enzymes for potentially novel PK and NRP.
Conclusions
The approach presented here highlights potential sources of metabolic novelty in the environment which will be a useful precursor to metagenomic biosynthetic gene cluster mining for PKs and NRPs which could provide leads for new antimicrobial metabolites
Screening for genes coding for putative antitumor compounds, antimicrobial and enzymatic activities from haloalkalitolerant and haloalkaliphilic bacteria strains of Algerian Sahara soils
Extreme environments may often contain unusual bacterial groups whose physiology is distinct from those of normal
environments. To satisfy the need for new bioactive pharmaceuticals compounds and enzymes, we report here the isolation of
novel bacteria from an extreme environment. Thirteen selected haloalkalitolerant and haloalkaliphilic bacteria were isolated from
Algerian Sahara Desert soils. These isolates were screened for the presence of genes coding for putative antitumor compounds using
PCR based methods. Enzymatic, antibacterial, and antifungal activities were determined by using cultural dependant methods.
Several of these isolates are typical of desert and alkaline saline soils, but, in addition, we report for the first time the presence of a
potential new member of the genus Nocardiawith particular activity against the yeast Saccharomyces cerevisiae. In addition to their
haloalkali character, the presence of genes coding for putative antitumor compounds, combined with the antimicrobial activity
against a broad range of indicator strains and their enzymatic potential, makes them suitable for biotechnology applications