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In the agricultural sector, a class of chemical compounds known as chlorinated phenol and phenoxyacetic acid are employed as herbicides, wood preservatives, and pesticides. Certain groups of chlorinated phenoxyacetic acid are used as herbicides for agricultural and domestic application. They are listed as priority pollutants by the United States Environmental Protection Agency (USEPA). Thus, this study focuses on bacterial isolation for 2,4-dichlorophenoxyacetic acid herbicide degradation been a toxic contaminant that hinders the quality of the soil over time, availability of certain soil microbes, non-targeted plants and poses health risk even to humans such as Hodking's lymphoma, respiratory infections e.t.c. These therefore, make it necessary to search for scientific way of dealing with this chemical from our environments. Incubation time, substrate concentration, pH, temperature, and inoculum size in mineral salt medium were all the parameters tested during the study, while 2,4-dichlorophenoxyacetic acid (2,4-D) herbicide was used as the alternative source of carbon. Following systemic dilution of sample on mineral salt medium, three bacterial isolates (D1, D2, and D3), were isolated and subjected to lots of screening. D2 was proven to be the best. During molecular identification that involves polymerase chain reaction, gel electrophoresis, sequence alignment and phylogentic analysis, the isolated bacteria was found to be Achromobacter xylosoxidans.The bacterial isolate grew and degraded 2,4-dichlorophenoxyacetic acid herbicide at optimum conditions of 96 h incubation time, 0.72g L−1substrate concentration, 7.5 pH, 40 °C temperature, and 400 μg/L inoculum size. High Performance Liquid Chromatography (HPLC) analysis of the residual 2,4-dichlorophenoxyacetic acid herbicide and the standard solution probe of the isolate was able to degrade up to 95.38 % of the substrate indicating great potentiality in bioremediation of herbicide polluted environments thereby, reducing if not all eliminating these toxic contaminants from our surroundings.

Lead is one of the most toxic heavy metals ever known by man today, which has zero biological role. It is known to cause anemia and affect the nervous and reproductive systems with irreversible effects. Its continual usage leads to its high accumulation polluting the soil and water bodies with devastating health effects. This research, aimed at isolation and characterization of indigenous lead tolerant bacteria from contaminated soil of Anka. Results of Atomic Absorption Spectrophotometry (AAS) showed high concentration of lead (738 mg/kg) of the affected sites above the EPA standard (400 mg/kg). Similarly, a mineral salt media was used to isolate the bacteria following serial dilution. An indigenous bacterial isolate (Ac) with potential to tolerate up to 3000 mg/L Pb(NO3)2was isolated and molecularly identified based on 16s rRNA sequencing as Bacillus cereus strain BUK_BCH_BTE2 with the accession number MT160412. The isolate was further characterized for its optimum growth and tolerance conditions using one factor at a time (OFAT). Sucrose with an optimum concentration of 5 g/L was the best carbon source for the isolate. The isolate was found to utilize ammonium sulphate as the best nitrogen source at a concentration of 2.5 g/L, with an optimum pH and tempertaure of 7.0 and 37 °C respectively. A concentration of 1000 mg/L Pb(NO3)2was found to be the optimum concentration for the isolate. The optimum incubation time and inoculum size were found to be 48 hrs and 100 μL respectively. The fact that the isolate could tolerate high Pb(NO3)2concentration makes it suitable for future bioremediation work involving lead.

This study was carried out for nine months to find bacterial strain capable of mineralizing 2,4-dichlorophenoxyacetic acid herbicide. A popular pre-/post emergent systemic herbicide known as 2, 4-dichlorophenoxyacetic Acid (2,4-D) is used to combat broad-leaved weeds and other plants on rangelands that are specifically intended to boost agricultural productivity and reduce losses the result of crop pests on agricultural products. This study's objective is to isolate, screen, and identify 2, 4-dichlorophenoxyacetic Acid degrading microorganisms from rice-growing soil in Kura local government area, Kano State. Experiments with incubation in mineral broth allowed for the isolation of 2, 4-dichlorophenoxyacetic Acid degrading bacteria. 2,4-dichlorophenoxyacetic Acid herbicide is added to salt medium. A native bacterial strain that can use 2, 4-dichlorophenoxyacetic Acid as its only source of carbon and energy was found in the soil of a rice field with a lengthy history of herbicide use. All the experiments were carried out in triplicates. Additionally, employed for data display were graphs and tables. An indigenous bacterial strain that is capable of 2,4-dichlorophenoxyacetic Acid supplementation in minimal salt medium were isolated from using 2,4-dichlorophenoxyacetic acid as the main alternative for energy and carbon from Rice cultivated lands. The strain named B3-BUK-BCH was recognized as Cupriavidus campinensisbased on the analysis of sequence of 16S ribosomal RNA, morphological, and chemical features. The mineralization features of isolated B3-BUK-BCH was quantified using one factor at a time approach. The optimal conditions for 2,4-dichlorophenoxyacetic Acid degradation were as follows: pH 7, temperature 40 °C, 200 gL−1inoculum size, and 0.72 gL−1of 2,4-D concentration. High-performance liquid chromatography (HPLC) was used to test the 2,4-D's propensity for degradation. Under ideal circumstances, up to 94.69% of the 2,4-D was degraded after 6 days of incubation, this isolate had never been reported as able to degrade 2,4-D based on the available literature in the study area. The isolated strain represents a great potential for bioremediation.

In recent years, the degradation of pollutants by microorganisms has emerged as a feasible and cost-effective strategy for restoring the quality of the environment. Anthracene is an integral part of many carcinogenic polyaromatic hydrocarbons (PAHs) and causes skin irritation. The aimed of the study is to investigate the anthracene-degrading ability bacteria and from environmental samples and characterized them using an enrichment technique. The bacterial strain was identified as Achromobacter xylosoxidans based on molecular identification achieved via 16SrRNA sequencing and phylogenetic analysis. The strain, designated as BUK_BTEG6 (accession number OM52853), was found to efficiently degrade anthracene as the sole carbon and energy source. A one factor at a time (OFAT) approach was utilized to determine the optimal growth factors that include substrate concentration, temperature, pH, and inoculum size. Results indicated that 400-600 mg/L was found as the optimal growth conditions as substrate concentration with temperature to be 35 °C, pH of 7.5 after 72 hours of incubation. Moreover, the GC-MS analysis of the culture medium confirmed the presence of degradation metabolites such as 9-10 anthraquinone, anthracene cis 1,2 dihydro diol, catechol, and cis-cis muconic acid. This isolate represents a potential candidate for use in environmental bioremediation strategies aimed at eliminating anthracene contamination from the environment.