In vitro assessment of crude oil degradation by Acinetobacter junii and Alcanivorax xenomutans isolated from the coast of Ghana.

This study was aimed at using in vitro microcosm experiments to assess crude oil degradation efficiency of Acinetobacter junii and Alcanivorax xenomutans isolated along Ghana's coast. Uncontaminated seawater from selected locations along the coast was used to isolate bacterial species by employing enrichment culture procedures with crude oil as the only carbon source. The isolates were identified by means of the extended direct colony transfer method of the Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectroscopy (MALDI-TOF MS), as Acinetobacter junii, and Alcanivorax xenomutans. Remediation tests showed that Acinetobacter junii yielded degradation efficiencies of 27.59 %, 41.38 % and 57.47 %. Whereas efficiencies of 21.14 %, 32.18 % and 43.68 % were recorded by Alcanivorax xenomutans representing 15, 30 and 45 days respectively. Consortia of Acinetobacter junii, and Alcanivorax xenomutans also yielded 32.18 %, 48.28 % and 62.07 % for the selected days respectively. Phylogenetic characterization using ClustalW and BLAST of sequences generated from the Oxford Nanopore Sequencing technique, showed that the Ghanaian isolates clustered with Alcanivorax xenomutans and Acinetobacter junii species respectively. An analysis of the sequenced data for the 1394-bp portion of the 16S rRNA gene of the isolates revealed >99 % sequence identity with the isolates present on the GenBank database. The isolates of closest identity were Alcanivorax xenomutans and Acinetobacter junii with accession numbers, NR_133958.1 and KJ147060.1 respectively. Acinetobacter junii and Alcanivorax xenomutans isolated from Ghana's coast under pristine seawater conditions have therefore demonstrated their capacity to be used for the remediation of crude oil spills.

Isolation and characterization of crude-oil-dependent bacteria from the coast of Ghana using oxford nanopore sequencing.

The utilization and improper use of crude oil can have irreparable damage on the environment and human populations. This study sought to isolate hydrocarbon utilizing bacteria from 1% v/v pristine seawater and 1% v/v crude oil using enrichment culture techniques. Whole genome sequencing of DNA using the Oxford Nanopore sequencing technique with Fastq WIMP as the workflow at 3% abundance was undertaken. The results showed that the most abundant isolates identified using this technique at specific sampling sites were, Acinetobacter junii (51.9%), Alcanivarax pacificus (15.8%), Acinetobacter haemolyticus (21.6%), Pseudomonas aeruginosa (23.4%), Alcanivorax xenomutans (24.7%), Alcanivorax xenomutans (23.0%) Acinetobacter baumannii (40.0%) and Acinetobacter junii (14.2%). Cumulatively, the most abundant isolates in the 8 sampling sites were Acinetobacter junii (17.91%), Alcanivorax xenomutans (11.68%), Pseudomonas aeruginosa (7.68%), Escherichia coli (7.67%), Acinetobacter haemolyticus (3.40%), and Alkanivorax pacificus (3.10%). Spearman's rank correlation analysis to examine the strength of relationship between the physicochemical parameters and type of bacteria isolated, revealed that salinity (0.8046) and pH (0.7252) were the highest. Isolated bacteria from pristine seawater, especially Escherichia coli have shown their capacity for bioremediating oil spill pollution in oceanic environments in Ghana.