Comparative analysis of microbiological indicators (heterotrophic and hydrocarbon-oxidizing bacteria) in bottom sediments and biochemical parameters (level of oxidized proteins (OP) and lipid peroxidation (LPO), superoxide dismutase (SOD), catalase (CAT), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities) in hepatopancreas of mussel Mytilus galloprovincialis (Lam.) from three Sevastopol bays - Laspi, Kazach’ya, Streletskaya (the Black Sea) was carried out. The results obtained allowed to identify certain differences between the studied areas and characterize their ecological state. The maximum abundance of heterotrophic and hydrocarbon-oxidizing bacteria was found in the most polluted Streletskaya Bay (95,000 and 250 cells/g respectively), the minimum - in the conventionally pure Laspi Bay (2,500 and 1.5 cells/g respectively). Parameters of prooxidant-antioxidant system (level of OP and LPO, SOD and CAT activities), as well as ALT activity in the hepatopancreas of mussels from Streletskaya Bay were found higher as compared to those in other tested areas. Most significant differences (more than twofold) in SOD activity, LPO content and basic ketone forms of OP levels were found between Laspi and Streletskaya bays. The results obtained indicate the severe pollution and less favorable living conditions for aquatic organisms in Streletskaya Bay, as well as demonstrate the high level of biochemical adaptation of mussels to complex environmental pollution. The studied parameters can be applied in the ecological monitoring of the coastal sea water areas.

Ologe Lagoon is one of Lagos, Nigeria’s five major lagoons, which provide essential ecosystem services such as agriculture, fishing, transportation, salt and sand mining, tourism, and industrial development. There are concerns, however, that the lagoon’s water may not be safe for the ecosystem functions it offers. As a result, the physicochemical properties, heavy metal concentrations, and microbial loads of water samples from the lagoon, as well as their health risks, were examined in this study. Physicochemical analysis showed that calcium, chloride, nitrates, sulphate, dissolved oxygen, acidity, alkalinity, total dissolved solid, and total suspended solid were present within the World Health Organization permissible limits, but not so for phosphate and temperature. The heavy metal analysis revealed that the water had non-permissible levels of iron, cadmium, chromium, nickel, manganese, and copper, but lead was normal. The microbiological examination showed abnormal bacteria counts, while coliform and fungus were not detected. The average daily oral and dermal exposure to cadmium, chromium, and nickel were higher than the recommended daily intake, but iron, lead, and copper were within the limits. The hazard quotient of oral and dermal exposure to cadmium, dermal exposure to chromium, and oral exposure to manganese were higher than the recommended limit (> 1). The carcinogenic risks of Cd, Cr, and Ni were also greater than the acceptable limit. The results obtained indicate that Ologe Lagoon’s water is unsafe for the lagoon’s ecosystem functions. Relevant agencies should ensure that waste is treated before being discharged into the lagoon.

The paper provides data on spatial distribution of petroleum hydrocarbons, heterotrophic and hydrocarbon-oxidizing bacteria in water and bottom sediments as well as on heavy metals in bottom sediments at different sites in the zone of fresh and saline water mixing, with the salinity range 1–18 ‰ during spring low water and high water. Physical and chemical characteristics of the bottom sediments are given. The highest hydrocarbon-oxidizing bacteria percentage of the heterotrophic bacterioplankton count in the indicated areas was found in April, with the maximum of 55 % determined in the transition zone waters. The share of hydrocarbon-oxidizing bacteria in the heterotrophic bacteria abundance in the water was larger than that in the bottom sediments. The highest concentrations of chloroform-extractable substances and petroleum hydrocarbons were detected in the marine zone bottom sediments, and their lowest concentrations were found in the river zone. During the period under study, the petroleum hydrocarbon input (in almost equal volumes) was constant, which is indicated by the hydrocarbon percentage of chloroform-extractable substances, which on average was 31 % for the marine zone, 29 % for the transitional zone, and 32 % for the river zone. In contrast to the river and transition zones, the concentration of chloroform-extractable substances observed in the marine zone bottom sediments was constant.

The present study has used soil samples from Nigeria, contaminated with Brass crude-oil, to determine its biodegradation through enhanced biostimulation with cow dung and periodic aeration. Over a period of twenty-eight days, the hydrocarbon-utilizing bacteria (HUB) and hydrocarbon-utilizing fungi (HUF) have been counted and identified. Results from biodegradation of the brass crude-oil over the aforementioned period show that amended crude-oil-spiked soil has had 54.82% degradation while for amendment and periodic turning this has been 55.90%, not significantly higher than the former at p≤0.05. Also degradation of spiked soil without cow dung amendment has been 16.13%. The identified HUB are Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis, and Streptococcus thermophillus, with individual occurrence of 18.52% as well as Proteus vulgaris and Micrococcus luteus with 11.11% and 14.81% occurrence, respectively. Also, the occurrence rate of HUF like Aspergillus flavus, A. niger, Penicillium chrysogenum, Trichothecium roseum, and Penicillium citrinum have been 15.63% each;whilefor Alternaria alternata and Neurospora crazza it has been 6.25% and for Saccharomyces cerevisae and A. fumigatus, 9.38%and3.13%, respectively. The study concludes that amendment with cow dung and periodic turning of the soil enhance degradation of Brass crude-oil significantly. What is more, aeration by periodic turning slightly improves degradation only with cow dung treatment on Days 21 and 28.

Bioremediation has become a trending and developing field in environmental restoration through the use of micro-organisms to utilize and reduced the concentration and toxicity of various chemical pollutants. This study is on bioremediation of hydrocarbon-polluted soils using some agricultural wastes. Ninety (90) plastic buckets were filled with 4kg each of the composite soil. The soil contained in the plastic buckets was spiked with 250ml crude oil, except in the unpolluted plastic buckets (0%) crude oil. The agro-wastes (plantain stem sap, bush mango peels, and fruited pumpkin husk powder) in single and combined forms were applied after 14 days soil pollution. The amendments were applied as follows: Pristine control (0% agro-wastes), crude-oil control (0% agro-wastes), 150g, 250g, and 350g of the agro-wastes. Soil samples were collected at 90 days for soil microbial counts and the total hydrocarbon content of the soil. Data collected were subjected to 2-way ANOVA. The result showed that the microbial population in the crude-oil polluted soil amended with different agricultural wastes significantly increased (p<0.05) the total heterotrophic and crude oil utilizing bacterial and fungal counts in the soils and the increase in microbial population result in a significant reduction in total hydrocarbon content (THC) of the soils. The reduction in the THC of the soil was treatment dependent. It is, therefore concluded that based on the efficiency of these agro-wastes in enhancing microbial degradation, further studies should be carried out on the enzyme activities and production of bio-surfactant from the wastes to shorten the degradation time.

Petroleum hydrocarbon contamination is a major global prevalent issue in the petroleum sector. This research focuses on evaluating biodegradation of three Gram-negative bacilli, isolated from cowpea planted soil, contaminated with kerosene. The Gram negative bacilli strains have been characterized and identified, using MicrobactTM ID24E systems for the identification of Enterobacteriaceae and common Miscellaneous Gram-Negative Bacilli (MGNB). The identified organisms include Aeromonas hydrophila, Vibrio parahaemolyticus, and Actinobacillus sp. with the biodegradation indices, monitored for the evaluation of their degrading abilities, being Optical density at 600 nm (OD600nm), pH, and emulsification stability. The chemical profile of single cultures and mixed cultures (consortia) on the jet fuel hydrocarbon has been determined by means of Gas Chromatography Mass Spectrometry (GC-MS), the results of which indicate that all the isolates have undergone above 70% reduction of the hydrocarbon substrates in terms of residual compounds. There has been 48 hydrocarbon compounds in the undegraded jet fuel which, following degradation process, decrease to 5, 13, 7, 10, 6, 9, and 10 compounds for Aeromonas hydrophila, Vibrio parahaemolyticus, Actinobacillus sp., Aeromonas hydrophila and Vibrio parahaemolyticus, Aeromonas hydrophila and Actinobacillus sp., Vibrio parahaemolyticus and Actinobacillus sp., Aeromonas hydrophila, Vibrio parahaemolyticus,and Actinobacillus sp., respectively. The degradation efficiency of the isolates have been relatively high and comparable to the control. Results from this study indicate that all the strains, especially the consortia, are potential candidates for remediating the problem of hydrocarbon contamination in the environment.