Novel investigation of the performance of continuous packed bed bioreactor (CPBBR) by isolated Bacillus sp. M4 and proteomic study.

The present study reveals the benzene degrading potential of bacterial species isolated from petroleum contaminated soil. Genomic analysis suggests that Bacillus sp. M4 was found to be dominating species. The process parameters were optimized and found to be pH 7.0 ±â€¯0.2, temperature 32 ±â€¯5 °C, immobilization time (20 days) and benzene concentration 400 mg/L. The maximum removal efficiency of benzene was calculated and found to be 93.13% at elimination capacity156 (mg/L/day) and inlet loading rate 192 (mg/L/day) achieved in 54th days of operation. In the study, the residual metabolites were analyzed by GC/MS analysis and identified as benzene-1,2-diol. In order to identify the responsible protein involved in the process of benzene biodegradation The proteomic study was performed and proteins were identified by MALDI-TOF analysis. The molecular docking was confirmed by the benzene biodegradation.

Biodegradation of wastewater in alternating aerobic-anoxic lab scale pilot plant by Alcaligenes sp. S3 isolated from agricultural field.

The isolated microbial Alcaligenes sp. S3 from the agricultural field was used for the biodegradation of synthetic wastewater containing atrazine. This study was conducted in an alternating aerobic-anoxic lab scale pilot plant. The performance of continuously operated pilot plant was evaluated in three different phases with varying atrazine concentration. The best performance of plant was observed in phase-II. The atrazine (200 mg/L) having COD value 1356 mg/L was used with varying flow rate and 90.56% COD removal was obtained at a flow rate of 300 mL/h on 122th day of operation. The effect of process parameter like pH and DO on the performance of the reactor was studied. The GC-MS analysis was investigated, and urea was found the intermediate/metabolites of atrazine biodegradation. The kinetic parameters such as half saturation rate constant (Ks) 106.80 mg/L; maximum specific growth rate (µmax) 0.208 per day and inhibition constant (Ki) 374.91 mg/L were evaluated by Andrew-Haldane model.

Biodegradation and kinetic study of benzene in bioreactor packed with PUF and alginate beads and immobilized with Bacillus sp. M3.

Benzene removal in free and immobilized cells on polyurethane foam (PUF) and polyvinyl alcohol (PVA)-alginate beads was studied using an indigenous soil bacterium Bacillus sp. M3 isolated from petroleum-contaminated soil. The important process parameters (pH, temperature and inoculums size) were optimized and found to be 7, 37°C and 6.0×108CFU/mL, respectively. Benzene removals were observed to be 70, 84 and 90% within 9days in a free cell, immobilized PVA-alginate beads and PUF, respectively under optimum operating conditions. FT-IR and GC-MS analysis confirm the presence of phenol, 1,2-benzenediol, hydroquinone and benzoate as metabolites. The important kinetic parameter ratios (µmax/Ks; L/mg·day) calculated using Monod model was found to be 0.00123 for free cell, 0.00159 for immobilized alginate beads and 0.002016 for immobilized PUF. Similarly inhibition constants (Ki; mg/L) calculated using Andrew-Haldane model was found to be 435.84 for free cell, 664.25 for immobilized alginate beads and 724.93 for immobilized PUF.

Biofiltration of xylene using wood charcoal as the biofilter media under transient and high loading conditions.

The main objective of this study was to evaluate the performance of wood charcoal as biofilter media under transient and high loading condition. Biofiltration of xylene was investigated for 150days in a laboratory scale unit packed with wood charcoal and inoculated with mixed microbial culture at the xylene loading rates ranged from 12 to 553gm-3h-1. The kinetic analysis of the xylene revealed absence of substrate inhibition and possibility of achieving higher elimination under optimum condition. The pH, temperature, pressure drop and CO2 production rate were regularly monitored during the experiments. Throughout experimental period, the removal efficiency (RE) was found to be in the range of 65-98.7% and the maximum elimination capacity (EC) was 405.7gm-3h-1. Molecular characterization results show Bacillus sp. as dominating microbial group in the biofilm.

Performance evaluation of Malathion biodegradation in batch and continuous packed bed bioreactor (PBBR).

The aim of this work was to study the biodegradation of Malathion in batch and continuous packed bed (Polyurethane foam; PUF) bioreactor (PBBR). After 10days, 89% Malathion removal was observed in batch PBBR. Continuous PBBR was operated at various flow rates (5-30mL/h) under optimum condition over a period of 75days. Inlet loading rates and elimination capacities were observed in the range of 36-216 and 7.20-145.4mg/L/day with an average removal efficiency of more than 90% under steady state conditions. GC/MS analysis confirms phosphorodithionicacid,O,O,S-trimethylester and diethylmercaptosuccinate as metabolites. Biodegradation of Malathion under inhibitory and non-inhibitory conditions was studied using Monod and Andrew-Haldane models and the kinetic constants were calculated and found to be µmax: 0.271 per day; Ks: 126.3mg/L using Monod and µmax: 0.315 per day; Ks: 151.32mg/L; Ki: 594.75mg/L using Andrew-Haldane models.