biostudies-literatureUnknown13Hentati DWe studied the biodegradation of oily sludge generated by a petroleum plant in Bahrain by a bacterial consortium (termed as AK6) under different bioprocess conditions. Biodegradation of petroleum hydrocarbons in oily sludge (C₁₁-C₂₉) increased from 24% after two days to 99% after 9 days of incubation in cultures containing 5% (w/v) of oily sludge at 40°C. When the nitrogen source was excluded from the batch cultures, hydrocarbon biodegradation dropped to 45% within 7 days. The hydrocarbon biodegradation decreased also by increasing the salinity to 3% and the temperature above 40°C. AK6 tolerated up to 50% (w/v) oily sludge and degraded 60% of the dichloromethane-extractable oil fraction. Illumina-MiSeq analyses revealed that the AK6 consortium was mainly composed of <i>Gammaproteobacteria</i> (ca. 98% of total sequences), with most sequences belonging to <i>Klebsiella</i> (77.6% of total sequences), <i>Enterobacter</i> (16.7%) and <i>Salmonella</i> (5%). Prominent shifts in the bacterial composition of the consortium were observed when the temperature and initial sludge concentration increased, and the nitrogen source was excluded, favoring sequences belonging to <i>Pseudomonas</i> and <i>Stenotrophomonas</i>. The AK6 consortium is endowed with a strong oily sludge tolerance and biodegradation capability under different bioprocess conditions, where <i>Pseudomonas</i> spp. appear to be crucial for hydrocarbon biodegradation.Frontiers in microbiology998076https://www.ebi.ac.uk/biostudies/studies/S-EPMC9532598biostudies-literatureBiotreatment of oily sludge by a bacterial consortium: Effect of bioprocess conditions on biodegradation efficiency and bacterial community structure.PMC9532598Ismail WHentati DAbed RMMEl Nayal AMAbotalib NAshraf IfalseBiotreatment of oily sludge by a bacterial consortium: Effect of bioprocess conditions on biodegradation efficiency and bacterial community structure.We studied the biodegradation of oily sludge generated by a petroleum plant in Bahrain by a bacterial consortium (termed as AK6) under different bioprocess conditions. Biodegradation of petroleum hydrocarbons in oily sludge (C₁₁-C₂₉) increased from 24% after two days to 99% after 9 days of incubation in cultures containing 5% (w/v) of oily sludge at 40°C. When the nitrogen source was excluded from the batch cultures, hydrocarbon biodegradation dropped to 45% within 7 days. The hydrocarbon biodegradation decreased also by increasing the salinity to 3% and the temperature above 40°C. AK6 tolerated up to 50% (w/v) oily sludge and degraded 60% of the dichloromethane-extractable oil fraction. Illumina-MiSeq analyses revealed that the AK6 consortium was mainly composed of <i>Gammaproteobacteria</i> (ca. 98% of total sequences), with most sequences belonging to <i>Klebsiella</i> (77.6% of total sequences), <i>Enterobacter</i> (16.7%) and <i>Salmonella</i> (5%). Prominent shifts in the bacterial composition of the consortium were observed when the temperature and initial sludge concentration increased, and the nitrogen source was excluded, favoring sequences belonging to <i>Pseudomonas</i> and <i>Stenotrophomonas</i>. The AK6 consortium is endowed with a strong oily sludge tolerance and biodegradation capability under different bioprocess conditions, where <i>Pseudomonas</i> spp. appear to be crucial for hydrocarbon biodegradation.2022-01-01T00:00:00Z20222024-11-07T00:30:50.799Z2024-11-07T00:30:50.799ZS-EPMC95325983621284210.3389/fmicb.2022.998076