Topic
Microbial biodegradation
About: Microbial biodegradation is a research topic. Over the lifetime, 1647 publications have been published within this topic receiving 75473 citations.
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TL;DR: In this article, the authors examined microbial ATP concentration and leucine incorporation rate in water, epiphytic biofilm and sediment of four surface flow mesocosm wetlands fed at different hydraulic loading rates during two periods with 10× and 3× diluted woodwaste leachate.
22 citations
TL;DR: This preliminary investigation showed that isolate Z08 has some toxic tolerance level which could detoxify refractory substances with great potential for cell protein recovery in high organic strength wastewater, therefore, strain Z08 could be employed in biodegradation of contaminated wastewater streams.
Abstract: A new photosynthetic bacterium isolate was morphologically identified as a non-motile rod-shape gram-negative bacterium. It produced a dark red culture under phototrophic condition, reproduced by budding and formed a lamellar intracytoplasmic membrane system parallel to cytoplasmic membrane, which contained bacteriochlorophyll a and caratenoids. It's physiological and nutrient requirement tests gave indication that the isolate thrived and multiplied in varied environmental conditions. It was consequently named Z08 and identified as Rhodobacter sphaeroides by 16SrDNA. Adaptation of Z08 to biodegradation of two environmentally concerned wastewaters, i.e. soybean and pharmaceutical wastewaters, attested its potential in wastewater bioremediation. Z08 adaptation in a suspended batch photobioreactor treating pharmaceutical wastewater at 3500lx radiation recorded best result after wastewater dilution of 1:4 with concomitant chemical oxygen demand reduction, biomass yield and specific growth of 50 %, 780 mg/L and 0.015/h, respectively at the lowest hydraulic retention time of three days. Furthermore, gas chromatography mass spectra analyses of treated and raw pharmaceutical wastewater indicated that high molecular weight recalcitrant compounds found in the pharmaceutical wastewater were transformed to less toxic and acceptable lower molecular weight substances through biodegradation. Whilst Z08 treatment of soybean wastewater under natural light intensity radiation recorded 80 % reduction, 1540 mg/L and 0.025/h for chemical oxygen demand, biomass and specific growth rate respectively regardless of the food to microorganism ratio. This preliminary investigation showed that isolate Z08 has some toxic tolerance level which could detoxify refractory substances with great potential for cell protein recovery in high organic strength wastewater. Therefore, strain Z08 could be employed in biodegradation of contaminated wastewater streams.
22 citations
TL;DR: Overall, the moderate and slow change of environmental conditions mediated by Carbo-Iron not only supported organohalide-respiring bacteria, but also created the basis for a subsequent microbial oxidation step.
22 citations
Journal Article•
TL;DR: In this paper, the authors focused on toluene and phenol because of their toxic and carcinogenic potentials, and selected two Bacillus strains as the most potent strains.
Abstract: The widespread release of aromatic hydrocarbons through spillages and leakage from underground tanks has caused extensive contamination of surface soils and sea and groundwater environments. Of these hydrocarbons, this study focused on toluene and phenol because of their toxic and carcinogenic potentials. Eight bacterial isolates (out of 109) utilized toluene and phenol as a sole source of carbon and energy. Two isolates were selected as the most potent strains. Based on their morphological and biochemical characterization, the eight bacterial isolates were identified as Micrococcus varians EPRIS14, Bacillus subtilis-EPRS12, Pseudomonas alcaligens EPRIS11, Bacillus licheniformis -EPRIS21,Bacillus laterosporus-EPRIS41, Pseudomonas putida-DAF1, Bacillus firmus-EPRIS22 and Acientobacter sp. EPRIS32. RAPD-PCR used as a supporting tool in the identification of the eight bacterial isolates. Influence of different nutritional and environmental parameters on the biodegradation rate of toluene and phenol by Bacillus subtilis-EPRIS12 and Bacillus laterosporus-EPRIS41 were investigated by measuring the growth rate by optical density and protein content of bacterial cell protein. Ammonium chloride and diammonium hydrogen phosphate were found to be the best nitrogen and phosphorous sources for the two bacterial strains, respectively. Concentration of NaCl at 2% was the optimum salt concentration for both isolates. At pH 7 the two strains exhibited growth rate ranged from (0.65-0.98) and protein content (0.44 and 0.45 µg/ml) while the optimum temperature was 30oC at which the growth ranged from (0.45-0.99) and the protein content of the cell ranged from (0.54-0.89µg/ml). Two most potent Bacillus strains were suggestive being applied in toluene and phenol biodegradation under all investigated nutritional and environmental condition in polluted soil and water.
22 citations
TL;DR: Biodegradation in the streams was characterized by an adaptation period (3-5 weeks for the stream as a whole, and reproducible from the previous year), which was inversely dependent on the concentration of pentachlorophenol and microbial biomass, and the sediment zone most significant to overall pentach chlorophenol biodegradation was the top 0.5- to 1-cm layer.
Abstract: The 2nd year of a 2-year study of the fate of pentachlorophenol in outdoor artificial streams focused on details of microbial degradation by a combination of in situ and laboratory measurements. Re...
21 citations