Biodegradation of polycyclic aromatic hydrocarbons by a bacterial consortium enriched from mangrove sediments

Abstract

Polycyclic aromatic hydrocarbons (PAHs) biodegradation in contaminated sediment is an attractive remediation technique and its success depends on the optimal condition for the PAH-degrading isolates. The aims of the current study was to isolate and identify PAHs-degrading bacteria from surface sediments of Nayband Bay and to evaluate the efficiency of statistically based experimental design for the optimization of phenanthrene (Phe) and Fluorene (Flu) biodegradation performed by enriched consortium. PAHs degrading bacteria were isolated from surface sediments. Purified strains were then identified by 16S rDNA gene sequence analysis. Taguchi L16 (45) was employed to evaluate the optimum biodegradation of Phe and Flu by the enriched consortium. Total of six gram-negative bacterial strains including Marinobacter hydrocarbonoclasticus, Roseovarius pacificus, Pseudidiomarina sediminum and 3 unidentified strains were isolated from enrichment consortium, using Fluorene (Flu) and phenanthrene (Phe) as the sole carbon and energy source. The enriched consortium showed highest degradation abilities (64.0% Flu and 58.4% Phe degraded in 7 days) in comparison to a single strain cultures or mixtures. Maximum biodegradation efficiency was occur at temperature = 35°C; pH = 8; inoculum size = 0. 4 OD600nm; salinity = 40 ppt; C/N ratio = 100:10. In conclusion our results showed that, indigenous bacteria from mangrove surface sediments of Nayband Bay have high potential to degrade Flu and Phe with the best results achieved when enriched consortium was used.

Microbial fuel cell fed by Barnett Shale produced water: Power production by hypersaline autochthonous bacteria and coupling to a desalination unit

“…Marinobacter hydrocarbonoclasticus is of great interest due to its extraordinary ability to degrade petroleum hydrocarbons (typically non-cyclic alkanes) and its capacity to use them as the sole source of energy and carbon. It degrades aromatic compounds under anaerobic conditions and is thus important in the field of bioremediation [18]. In addition, M. hydrocarbonoclasticus has unique features such as extreme salt tolerance which ranges from 5000 to 205,000 mg/L NaCl, and the capacity to grow either in aerobic or anaerobic conditions, which provides a competitive advantage.…”

Exploring the microbial diversity in oil-contaminated mangrove sediments using 16S rRNA metagenomics

“…However, few studies have been conducted on the different bacterial communities and diversity in mangrove sediments exposed to crude oil contamination. The aim of this study was to assess the bacterial community structure and composition in sediments of the Nayband Bay mangrove forests that had been negatively affected by oil pollution as a result of development of the South Pars oil field in the Assaluyeh region [3,2]. To our knowledge, this is the first description of the bacterial community found in Iranian mangrove sites using an NGS approach.…”

“…Despite its ecological importance in the Persian Gulf, Nayband Bay is surrounded by oil and gas facilities of the Pars Special Economic Energy Zone (PSEEZ) in the north-west. Growing industrial activity in the area and its consequent marine polluting effects has resulted in damage and has threatened marine habitats in the Nayband Bay in recent years [3,2]. Several studies have shown that contamination with petroleum hydrocarbons affects the structural and functional diversity of bacterial populations in the contaminated soils and sediments [4][5][6], which may have large ecological implications.…”

“…Several studies have shown that contamination with petroleum hydrocarbons affects the structural and functional diversity of bacterial populations in the contaminated soils and sediments [4][5][6], which may have large ecological implications. Although there are some reports on the microbiology of the mangrove environment in Nayband Bay [3,[7][8][9], almost all of the studies have concentrated on the culture-dependent analysis of polycyclic aromatic hydrocarbon (PAH)-degrading bacteria from this environment. To date, a comprehensive description of the microbial life in this mangrove ecosystem that has been exposed to oil pollution is lacking.…”

Celeribacter persicus sp. nov., a polycyclic-aromatic-hydrocarbon-degrading bacterium isolated from mangrove soil

“…The abundance and diverse physiological characteristics within this group indicate that these bacteria function to degrade aromatic compounds (Buchan et al, 2005) and participate in the biogeochemical cycles of carbon and sulfur (Lenk et al, 2012). During attempts to investigate the oil-degrading bacteria of mangrove sediments in Nayband Bay (278 27.5199 N 528 40.5459 E) in the Iranian Persian Gulf, strain SBU1 T , which is able to degrade polycyclic aromatic hydrocarbons, was isolated (Shahriari Moghadam et al, 2014). In this study, strain SBU1 T was found to form a clade with Celeribacter indicus P73 T , based on comparison of 16S rRNA gene sequences.…”