Optimization of bioremediation-cocktail for application in the eco-recovery of crude oil polluted soil

Abstract

Background: Environmental sustainability is the driver for finding the optimal bioremediation cocktail with the combination of highly potent hydrocarbonoclastic strains and the nutrient additives that significantly enhance mineralization of crude oil in polluted soil in order to mitigate its deleterious effects on the environment. In this study, four hydrocarbon-degrading bacterial strains were pre-selected from mined rhizobacterial isolates in aged crude oil-contaminated soil. Method: Agrowaste residues of poultry-droppings, corn chaff, and plantain peel were selected among others for their ability to support high biomass of selected bacterial strains. Baseline proximate analysis was performed on the agrowaste residues. Simplified, one variable at a time (OVAT) was employed in the validation of the variables for optimization using the Multivariate analysis tool of Response Surface Methodology (RSM). To test the significant formulation variables, the Box-Behnken approach using 15 runs design was adopted. Results: The rate of contaminant removal was observed to fit into a quadratic function. For optimal rate or contaminant removal, the fitted model predicted the optimal formulation cocktail condition to be within 0.54 mg/kg (Corn steep liquor), phosphate 137.49 mg/kg (poultry droppings) and 6.4% inocula for initial TPH of 9744 mg kg-1 and THC of 9641 mg kg-1 contaminant level. The model for the application of the bioremediation product and the variables evaluated had a significant p-value < 0.005 for the attainment of 85 to 96 % of TPH and THC removal after 56 days of treatment. Conclusions: This study has shown the need to harness the abundant agrowaste nutrients in supporting high throughput rhizobacteria in the formulation of a bioremediation agent suitable for use in the reclamation of oil spill sites in the Niger Delta oil-producing region.

Kinetic Modelling of Oxalic Acid Production from Cassava Whey by Aspergillus niger

“…Monoculture cultivation and fermentation have limits. Other research has identified the role of mixed cultures in mitigating the issues that monoculture systems face [31,32,25,33].The congruency of model parameters obtained in this study is likewise consistent with a trend previously described by other researchers. The substrate consumption rates (14.28 and 11.16 mg/g/day) for the cassava whey and yeast extract with an R 2 value of 0.96 an d 0.94 respectively indicated that there was a healthy utilization of Cassava whey and yeast extract for the generation of oxalic acid and that the process was growth associated.…”

Bacterial microbiota of the contact lens surface and associated care behaviours

“…The main pathogens that were found in the present population were represented by 13 strains: Serratia surfactantfaciens (10%), Staphylococcus epidermidis (5%), S. pasteuri (65%), Stenotrophomonas maltophilia (5%), Pseudomonas aeruginosa (10%), Delftia tsuruhatensis (5%), Acinetobacter calcoaceticus (5%), Granulicatella adiacens (5%), Raoultella planticola (10%), R. ornithinolytica (5%), A. agilis (35%), Pseudomonas stutzeri (5%), and Acinetobacter junii (5%). Sources of contamination are normally residential water, rivers, soil, mud, and some plants [ 19 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 ], which might be related to the CL care routines and nonhygenic environments. For contamination by nonpathogenic species, 13 strains were found: Brevundimonas albigilva , E. mori, Herbasprillum aquaticum, Kluyvera intermedia , Pseudomonas geniculata , Acinetobacter lactucae , Bacillus wiedmanni , Curtobacterium plantarum , Paludibacterium paludis, Kosakonia oryziphila , Rothia kristinae , Acinetobacter soli, and Streptococcus periodonticum.…”

“…(2020) [ 36 ] Agbaji et al. (2020) [ 37 ] Vandamme et al. (2016) [ 38 ] P. stutzeri 5 soil, water Gilardi (1972) [ 39 ]; Lalucat et al.…”

Screening, Characterization and Identification of Sophorolipid-Producing Yeast Isolated from Palm Oil Effluent Polluted Soil

“…Permeability of the soil using the samples was determined through the ASTM-D2434 method while Atterberg Limits was determined using ASTM-6913 for a soil moisture test. The pH of the soil samples was determined using the electrochemical method Agbaji et al, [22]. Electrical conductivity was determined using the method of APHA, [23].…”

“…The exchangeable ammonia or ammoniacal nitrogen was determined using the APHA, [23] method. The modified methods of Effiong et al [24]; Orhohoro et al [25] and Agbaji et al, [22] was employed in the analysis of parameters such as heavy metals, hydrogen sulphides and salinity.…”