Analysis of Antarctic proteobacteria by PCR fingerprinting and screening for antimicrobial secondary metabolites

Abstract

ABSTRACT. Fifty-seven proteobacterium species were successfully isolated from soils of Barrientos Island of the Antarctic using 11 different isolation media. Analysis of 16S rDNA sequencing of these isolates showed that they belonged to eight different genera, namely Bradyrhizobium, Sphingomonas, Methylobacterium, Caulobacter, Paracoccus, Ralstonia, Rhizobium, and Staphylococcus. All isolates were studied for capability of producing antimicrobial and antifungal secondary metabolites using high-throughput screening models. Approximately 23 (13/57) and 2% (1/57) of isolates inhibited growth of Candida albicans ATCC 10231 T and Staphylococcus aureus ATCC 51650 T , respectively. These results indicated that proteobacterium species isolates from Antarctic could serve as potential source of useful bioactive metabolites. Enterobacterial repetitive intergenic consensus (ERIC)-PCR fingerprinting produced nine clusters and 13 single isolates, with a high D value of 0.9248. RAPD fingerprinting produced six clusters and 13 single isolates, with a relatively low D value of 0.7776. ERIC-PCR analysis proved to have better discrimination capability than RAPD analysis and generated better clustering for all proteobacterium species isolates. We conclude that ERIC-PCR is a robust, reliable and rapid molecular typing method for discriminating different genera of proteobacteria.

Peer Review #1 of "Detection of antibiotic-resistant bacteria endowed with antimicrobial activity from a freshwater lake and their phylogenetic affiliation (v0.1)"

“…The dendrogram generated by BOX-PCR also consist of cluster A and B. Staphylococcus, Lysinibacillus, Achromobacter, Bacillus and Aneurinibacillus were grouped together in cluster A. Cluster B of different genera belonging to Bacterium, Azospirillum, Methylobacterium, Bosea and Novosphingobium which was in agreement with the findings of Lee et al (2012). BOX-PCR fingerprinting shows that it is very useful technique to differentiate between very closely related bacterial strains identification and has been applied to study the great genetic diversity at species level (Versalovic et al, 1991).…”

Bacterial Biodiversity in Midguts of Anopheles Mosquitoes, Malaria Vectors in Southeast Asia

“…Similar antagonism was observed between Sphingomonas and enterobacteria in mosquitoes from Vietnam. Sphingomonas is a sparsely known genus but antimicrobial activities against Candida have been described recently [73]. Culture of the natural isolates of P. fluorescens, Serratia, Acinetobacter and Sphingomonas should confirm these potential antagonisms and give insights about their mechanism.…”

Kombucha Multimicrobial Community under Simulated Spaceflight and Martian Conditions

“…The nucleic acids were quantified and qualified by a NanoDrop ND-1000 spectrophotometer (NanoDrop Technologies, Wilmington, DE). Two RAPD primers: OPO10 (5'-TCAGAGCGCC-3') for proteobacteria (Lee at al., 2012) and OPX-03 (5'-TGGCGCAGTG-3') for yeasts (Echeverrigaray at al., 2000) were chosen for amplifying kombucha microbial DNA in the experiment as it provided reproducible and discriminatory banding patterns. The 5 PCR mixture consisted of a 100 ng microbial genomic DNA, 2.0 µl 10х PCR buffer with 20 mM MgCl 2 , 2.0 µl 10 mM dNTPs, 1 U Taq polymerase, 20 pM RAPD primer, and sterile ultrapure water was added to a final volume of 20 µl.…”