Optimization Of Biodegradation Research Articles

Bioremediation of textile industrial effluents by Fomitopsis pinicola IEBL-4 for environmental sustainability

Industrialization not only revolutionized the life in the past few decades but also leads to environmental pollution by the continuous addition of effluents. There is need to develop techniques for the economic bioremediation of toxic effluents to maintain sustainable environment. In current study, the textile industrial effluent’s biodegradation potential of a locally isolated brown rot fungi, Fomitopsis pinicola IEBL-4, was analyzed and optimized. Response surface methodology under Box–Behnken design was employed for the biodegradation of three industrial effluents. The analysis of biodegradation is followed by the study of the ligninolytic enzymes, i.e., manganese peroxidase, lignin peroxidase, and laccase during the process. Biological oxygen demand (BOD) and chemical oxygen demand (COD) of effluents after treatment were determined to check the quality of the biodegradation process. The results showed that there was 72.06 ± 1.76%, 75.15 ± 1.72%, and 79.02 ± 1.62% biodegradation of MT, FST, and ST effluents, respectively after optimization of fungal growth conditions. Addition of various carbon and nitrogen sources further increase biodegradation 15%, 5%, and 9% for MT, FST, and ST effluents, respectively. There was continuous decrease in the values of BOD and COD after each optimization step and values were well below the WHO recommended after final biodegradation. The BOD of MT effluent reduces from 358.30 mg/L to 49.31 ± 0.87 mg/L, 347.2 mg/L to 51.12 ± 0.76 mg/L for FST effluent, and 412.2 mg/L to 45.34 ± 0.9 mg/L for ST effluent after optimization of biodegradation at two stages. The study of ligninolytic enzymes showed that these are involved in the biodegradation process and lignin peroxidase is the most active among all three. The maximum activities calculated were 942.60 ± 5.70 U mL−1 min−1 for LiP, 694.20 ± 4.10 U mL−1 min−1 for MnP, and 435.60 ± 3.30 U mL−1 min−1 for laccase. The enzymatic activities vary with the biodegradation of the effluent suggested dyes dependent secretion of the enzymes. This study could be concluded that F. pinicola IEBL-4 is suitable fungus for the bioremediation of textile industrial effluents.

Aerobic biodegradation and optimization of 2,4-Dichlorophenoxyacetic acid by E. hormaechei subsp. Xiangfangensis and assessment of biodegraded metabolite toxicity

Nature has its hidden battalion against all the manmade environmental contaminations. Ethno-medicinal plants and their hidden microbiome are the natural treasures that are in need to be explored The present work is focused on isolating the endophytic bacteria of Annona reticulata, Cinnamomum zeylanicum and Gloriosa superba Isolated bacterial strains are screened for the potential degrader of 2,4-D depending on their efficiency to tolerate a higher mg L−1 of 2,4-D. Enterobacter hormaechei Subsp. xiangfangensis strain 19_357_F (MK281611), isolated from the bark explant was capable of co-existing and utilizing 2,4-D as a source of nourishment, thus degrading 2,4-D to 2,4-DCP. The optimization of biodegradation was carried out using one factor at a time (OFAT) approach and the isolated strain could tolerate 400 mg L−1 of 2,4-D while degrading 250 mg L−1 of dye accounting for 42.68% degradation at 72 h. The present study indicates the endophyte Enterobacter hormaechei subsp. xiangfangensis strain 19_357_F capable of utilizing 2,4-D as the sole source of energy, on further increasing the 2,4-D above 400 mg L−1 the bacterial toxicity was induced demonstrating the reduction in the bacterial cell count The current study also reported the biodegraded metabolite 2,4-DCP more toxic than the parent compound and suggestive of increasing the time of incubation. The endophyte Enterobacter hormaechei subsp. xiangfangensis strain 19_357_F is considered efficient as it can degrade 2,4-D at 250 mg L−1 with 42.68% quantitatively. The aim of the study is to explore these potential organisms as tool for bioremediation and enhance the environmental self-sustainability as these endophytes are safer, reliable, non-pathogenic and eco-friendly.

Optimization of Polystyrene Biodegradation using Response Surface Methodology (RSM) Measured by Simple Colorimetric Method

Nearly 280 kilotons of polystyrene (PS) waste being discarded yearly in Malaysia. Banning usage of PS food packaging aims to minimize this “white pollution”. However, the existing PS waste volume remains the same despite the termination of PS production. Therefore, this study has investigated the optimization of biodegradation of PS using isolated strain Bacillus aryabhattai as an alternative solution to the biodegradation of recalcitrant plastic. The effect of pH and temperature as independent variables were studied at three levels each (pH: 6, 7.5 and 9, temperature: 25 °C, 35 °C and 45 °C) under the designation by three level-factorial and analysed using response surface methodology (RSM) by Design Expert Version 10.0. The biodegradation activity of Bacillus aryabhattai was quantified using simple colorimetric method. Bacillus aryabhattai was inoculated on the dye PS-film and incubated under designed conditions. As a result of biodegradation, the entrapped methylene blue dye was released and measured photometrically. Optimum conditions for the highest reading of blue dye absorbance were obtained at pH 9 and temperature of 25ºC with the desirability of 75.9%. This study provides significant information on the biodegradation activity of Bacillus aryabhattai for future research that can be applied in waste management.

Biodegradation kinetics of diuron by Pseudomonas aeruginosa FN and optimization of biodegradation using response surface methodology

AbstractDiuron is a selective and the most persistent herbicide. Widespread use of this compound has led to the elevated concentrations of diuron in groundwater and wastewater. The main objectives of this study were to investigate biodegradation of diuron by Pseudomonas aeruginosa FN and evolved degradation product, 3,4‐dichloroanilines (3,4‐DCA). The influence of temperature, initial optical density of Pseudomonas aeruginosa FN and initial diuron concentration were examined to further optimize biodegradation of diuron, and the effect of these factors were investigated by the response surface methodology (RSM) and full factorial design (FFD). The optimal biodegradation conditions were obtained at T = 25°C, γ (diuron) = 0.5 mg/L and initial optical density of 0.2. The biodegradation kinetic of diuron was described by Monod model and the obtained value of F‐test was grater that 0.96 which showed good correlation between Monod model and experimental results.

Biodegradation of alkali lignin by a newly isolated Rhodococcus pyridinivorans CCZU-B16.

Based on the Prussian blue spectrophotometric method, one high-throughput screening strategy for screening lignin-degrading microorganisms was built on 24-well plate at room temperature. One high activity of alkali lignin-degrading strain Rhodococcus pyridinivorans CCZU-B16 was isolated from soil. After the optimization of biodegradation, 30.2% of alkali lignin (4g/L) was degraded under the nitrogen-limited condition (30/1 of C/N ratio; g/g) at 30°C for 72h. It was found that syringyl (S) units and guaiacyl (G) in lignin decreased after biodegradation. Moreover, the accumulated lipid in cells had a fatty acid profile rich in C16 and C18 with four major constituent fatty acids including palmitic acid (C16:0; 22.4%), palmitoleic acid (C16:1; 21.1%), stearic acid (C18:0; 16.2%), and oleic acid (C18:1; 23.1%). In conclusion, Rhodococcus pyridinivorans CCZU-B16 showed high potential application in future.

Pseudomonas sp. ZXY-1, a newly isolated and highly efficient atrazine-degrading bacterium, and optimization of biodegradation using response surface methodology

Atrazine, a widely used herbicide, is increasing the agricultural production effectively, while also causing great environmental concern. Efficient atrazine-degrading bacterium is necessary to removal atrazine rapidly to keep a safe environment. In the present study, a new atrazine-degrading strain ZXY-1, identified as Pseudomonas, was isolated. This new isolated strain has a strong ability to biodegrade atrazine with a high efficiency of 9.09mg/L/hr. Temperature, pH, inoculum size and initial atrazine concentration were examined to further optimize the degradation of atrazine, and the synthetic effect of these factors were investigated by the response surface methodology. With a high quadratic polynomial mathematical model (R2=0.9821) being obtained, the highest biodegradation efficiency of 19.03mg/L/hr was reached compared to previous reports under the optimal conditions (30.71°C, pH7.14, 4.23% (V/V) inoculum size and 157.1mg/L initial atrazine concentration). Overall, this study provided an efficient bacterium and approach that could be potentially useful for the bioremediation of wastewater containing atrazine.

Biodegradation of Palm Oil Mill Effluent

Aims: The aim of this study was to investigate the biodegradation capacity of selected indigenous fungal isolates and optimization of their degradation ability using various environmental factors such as pH, incubation temperature, nutrient concentration and inoculums size in reducing pollution effect of palm oil mill effluent (POME) in the environment. Place and Duration of Study: Two fungal isolates Candida rugosa and Geotrichum candidum used in this work were previously isolated from POME sample collected from Starline palm oil mill industries, Umukalika, Obingwa LGA, Abia state Nigeria in previous work of authors. The study was carried out from March to August, 2013. Methodology: Spore suspension was prepared by adding 10 ml of 0.1% Tween 80 onto PDA slant of 5 days old culture of Candida rugosa and Geotrichum candidum respectively. Biodegradation of POME was carried out by inoculating 0.1ml (10spores/ml) of respective fungal isolates into different 500 ml Erlenmeyer flasks containing 100ml each of raw POME. They were incubated at 30oC on a rotary shaker (200rpm). Samples were taken every 24hrs for 144hrs to determine BOD, COD, oil & grease. Similarly, optimization of biodegradation was carried out by studying the effect of different environmental conditions such as different initial pH levels (4.0-8.0), incubation temperature (25-50oC), concentrations of soy bean (1.5-4.5% w/v) and inoculum size (0.1-0.5 v/v). The experiments were done in triplicates. Results: Biodegradation studies with selected indigenous fungi showed that C. rugosa Original Research Article British Microbiology Research Journal, 4(12): 1440-1450, 2014 1441 was able to remove (44.6%) BOD, (13.9%) COD , (50.7%) oil and grease (O&G) while G. candidum reduced BOD, COD, O&G by 46.9%,16.9% and 64,9% respectively after 144hrs. Optimization of degradation in POME using various environmental and nutrients conditions revealed that at pH 8, C. rugosa showed best degradation of COD (48.6%), BOD (74.5%), O&G (41.8%) removal while COD (59.1%), BOD (75.7%) , O&G (59.1%) removal was observed with G. candidum treatment. The optimal incubation temperature for degradation using each of fugal isolates was at 35oC with 85.2% BOD , 71.8% COD and 67.3% O&G removal for C. rugosa , 87.3% BOD and 63.4% COD for G. candidum .The best degradation ability for C. rugosa and G. candidum were demonstrated at 3.5w/v and 2.5w/v soybean concentrations respectively. The result also showed that increase in inoculum size could not completely reduce oil and grease during degradation process possibly because no single culture supports degradation optimally due to presence of complex sugars Conclusion: The selected fungal isolates exhibited high efficiency for removal of oil and grease as well as organic matter from POME but required control of environmental conditions and nutrient expansion for the effective biodegradation of POME.