AACL Bioflux, vol: 12,5 (2019)
Genetic screening of a marine pigmented nrps-producing bacterium associated with brown algae exhibiting anti-vibrio activity
Lunggani A.T., Imtiyaz F.D., Darmanto Y.S., Radjasa O.K., Sabdono A.
Abstract
The Vibrio spp. bacterium has caused many problems in the aquaculture industry and human health, which led to the discovery of new compounds from marine microorganisms. Thus, the study was conducted to isolate and identify a symbiotic bacterium from brown algae, evaluate its anti-Vibrio properties against three Vibrio bacteria (V. harveyi, V. vulnificus and V. parahaemolyticus) and characterize its non-ribosomal peptide synthetases (NRPS) gene, which is amplified using specific primers. Out of 45 pigmented bacterial symbionts isolated from three brown algae, only 11 isolates exhibited anti-Vibrio activity against at least one Vibrio bacteria, and there was no pathogenic pattern when those selected bacteria were inoculated on blood agar. Moreover, all those 11 bacteria were subjected for fermentation and extraction using ethyl acetate to assess their crude extract against three Vibrio isolates. The results also showed that all crude extracts from the selected bacteria exhibited zones of inhibition ranging from 1 to 3 mm for at least one Vibrio bacteria, except the karimun B (KRB) isolate that presents no inhibition. Furthermore, the karimun G (KRG) isolate, a bright yellow bacterium, which demonstrated a broad halo inhibiting zone, was identified as Aurantimonas coralicida according to 16SrRNA and detected to have NRPS fragments when it is visualized in electrophoresis. However, the sequences of its NRPS are close to Pseudomonas psychrotolerans. © 2019, BIOFLUX SRL. All rights reserved.
Keyword: Aurantimonas coralicida; Brown algae associated bacteria; Marine pigmented bacteria; NRPS gene; Vibriosis