Phenol degrading ability of Rhodococcus pyrinidivorans and Pseudomonas aeruginosa isolated from activated sludge plants in South Africa

Biological Control of Fusarium oxysporum f. sp. cubense Tropical Race 4 Using Natively Isolated Bacillus spp. YN0904 and YN1419

Fusarium wilt of banana (FWB) is the main threatening factor for banana production worldwide. To explore bacterial biocontrol resources for FWB, the antagonistic effective strains were isolated from banana-producing areas in Yunnan Province, China. Two isolates (YN0904 and YN1419) displaying strong antagonism against Tropical Race 4 (TR4) were identified from a total of 813 strains of endophytic bacteria. TR4 inhibition rates of YN0904 and YN1419 were 79.6% and 81.3%, respectively. By looking at morphological, molecular, physiological and biochemical characteristics, YN0904 was identified as Bacillus amyloliquefaciens, while YN1419 was identified as B. subtillis. The control effects of YN0904 and YN1419 on TR4 in greenhouse experiments were 82.6% and 85.6%, respectively. Furthermore, YN0904 obviously promoted the growth of banana plantlets. In addition, biocontrol marker genes related to the biosynthesis of antibiotics synthesized and auxin key synthetase genes could be detected in YN0904. Surprisingly, the marker gene sboA could be exclusively detected in YN1419, while other marker genes were all absent. Molecular characterization results could provide a theoretical basis for expounding the biocontrol mechanisms of these two strains. We concluded that natively antagonistic strains derived from local banana plantations could provide new biological control resources for FWB.

A quantitative analysis method to determine the amount of cellulose fibre in waste sludge

A novel quantitative analysis method for cellulose fibre was developed to understand its behaviour in biological wastewater treatment and waste sludge processes. The method developed in this study was designed using Pseudomonas aeruginosa to remove it by dissolving all the organic components except cellulose from the sludge due to needing the solubilisation of bacteria occupied almost of sludge matrix and quantifying the amount of remaining cellulose. The results of this study indicated that a combined treatment process that employed 2,000 U/L protease, 2 M hydrogen peroxide, and 2 mM potassium hydroxide after pre-treatment for floc dispersion with an ultrasonic treatment at 26 W for 1 min resulted in a solubilisation of 96% of P. aeruginosa without losing the cellulose fibre. When it was applied to the cellulose fibre added in the sludge from a municipal wastewater treatment facility, 99.5% of the cellulose fibre was recovered by using the high-speed centrifuge.

A new Rhodococcus aetherivorans strain isolated from lubricant-contaminated soil as a prospective phenol-biodegrading agent

Microbe-based decontamination of phenol-polluted environments has significant advantages over physical and chemical approaches by being relatively cheaper and ensuring complete phenol degradation. There is a need to search for commercially prospective bacterial strains that are resistant to phenol and other co-pollutants, e.g. oil hydrocarbons, in contaminated environments, and able to carry out efficient phenol biodegradation at a variable range of concentrations. This research characterizes the phenol-biodegrading ability of a new actinobacteria strain isolated from a lubricant-contaminated soil environment. Phenotypic and phylogenetic analyses showed that the novel strain UCM Ac-603 belonged to the species Rhodococcus aetherivorans, and phenol degrading ability was quantitatively characterized for the first time. R. aetherivorans UCM Ac-603 tolerated and assimilated phenol (100% of supplied concentration) and various hydrocarbons (56.2–94.4%) as sole carbon sources. Additional nutrient supplementation was not required for degradation and this organism could grow at a phenol concentration of 500 mg L⁻¹ without inhibition. Complete phenol assimilation occurred after 4 days at an initial concentration of 1750 mg L⁻¹ for freely-suspended cells and at 2000 mg L⁻¹ for vermiculite-immobilized cells: 99.9% assimilation of phenol was possible from a total concentration of 3000 mg L⁻¹ supplied at daily fractional phenol additions of 750 mg L⁻¹ over 4 days. In terms of phenol degradation rates, R. aetherivorans UCM Ac-602 showed efficient phenol degradation over a wide range of initial concentrations with the rates (e.g. 35.7 mg L⁻¹ h⁻¹ at 500 mg L⁻¹ phenol, and 18.2 mg L⁻¹ h⁻¹ at 1750 mg L⁻¹ phenol) significantly exceeding (1.2–5 times) reported data for almost all other phenol-assimilating bacteria. Such efficient phenol degradation ability compared to currently known strains and other beneficial characteristics of R. aetherivorans UCM Ac-602 suggest it is a promising candidate for bioremediation of phenol-contaminated environments.

Sorption of phenol from synthetic aqueous solution by activated saw dust: Optimizing parameters with response surface methodology

Organic pollutants have an adverse effect on the neighboring environment. Industrial activates are the major sources of different organic pollutants. These primary pollutants react with surrounding and forms secondary pollutant, which persists for a long time. The present investigation has been carried out on the surface of activated sawdust for phenol eliminations. The process parameters initial concentration, contact time, adsorbent dose and pH were optimized by the response surface methodology (RSM). The numerical optimization of sawdust (SD), initial concentration 10 mg/l, contact time 1.5 h, adsorbent dose 4 g and pH 2, the optimum response result was 78.3% adsorption. Analysis of variance (ANOVA) was used to judge the adequacy of the central composite design and quadratic model found to be suitable. The coefficient of determination values was found to be maximum Adj R² 0.7223, and Pre R² 0.5739 and significant regression at 95% confidence level values.

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Adsorption of phenol contains water and wastewater.

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Chemical toxicity of phenol affects the air, water, and soil.

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Operating parameters optimization with response surface methodology (RSM).

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Saw dust as bio-adsorbent material.

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Physicochemical characteristics of activated sawdust.

Draft Genome Sequence of a Pseudomonas aeruginosa Strain Able To Decompose N , N -Dimethyl Formamide

Pseudomonas aeruginosa is a Gram-negative bacterium, which uses a variety of organic chemicals as carbon sources. Here, we report the genome sequence of the Cu1510 isolate from wastewater containing a high concentration of N,N-dimethyl formamide.