Biodegradation of phenol by a novel diatom BD1IITG-kinetics and biochemical studies

Abstract

A phenol-degrading novel diatom BD1IITG was isolated from petroleum refinery wastewater and characterized (GenBank Accession No. KJOO2533). HPLC analysis showed the diatom could degrade phenol in the concentration range of 50-250 mg/l in Fog's media. The highest specific growth and degradation rate were achieved at 100 mg/l phenol. It could also mineralize phenol along with aliphatics in petroleum refinery wastewater. Growth kinetic modeling shows that Haldane model best represents the growth behavior of the diatom in nutrient media as well as refinery wastewater. Biokinetic parameters suggest that the diatom possesses higher maximum specific growth rate (l max = 0.4 day -1 ), better tolerance to toxicity (K I = 90.24 mg/l) and high phenol affinity (K s = 20.99 mg/l) in refinery wastewater as compared to Fog's media confirming practical applicability of the strain for wastewater treatment. FTIR fingerprinting of biomass indicates intercellular phenol uptake and breakdown into its intermediates via phenol degradation pathway. Pathway was elucidated using HPLC, LC-MS and UV-visible spectrophotometry confirming prominence of ortho-over meta pathway for phenol metabolism. The diatom produces biosurfactant with highest emulsifying activity at 100 mg/l phenol which may contribute to highest degradation rate at this concentration. Infrared analysis confirms increased biosynthesis of lipids and polysaccharides in phenol-degrading biomass, indicating its potential use as feedstock of clean ecofriendly energy sources as biodiesel or bioethanol. The phenol degradation capability coupled with potential applicability of the spent biomass as biofuel feedstock makes diatom BD1IITG a potential candidate for a clean environmentally sustainable process. Graphical Abstract

Biodegradation of toxic organic compounds using a newly isolated Bacillus sp. CYR2

“…Due to its high water solubility, phenol present in wastewaters easily reaches downstream water sources and may be harmful to life in aquatic environments [3]. Biodegradation of phenols, as well as many petroleum products by microorganisms, represents the primary way by which these compounds are removed from contaminated sites.…”

A cost-effective and environmentally sustainable process for phycoremediation of oil field formation water for its safe disposal and reuse

“…The growth of algal biomass in oil field formation water was monitored at regular intervals of 24 hours by optical density measurement at 560 nm in UV-Visible Spectrophotometer (UV-1800, Shimadzu, Japan) as well as by dry weight analysis 30,58 . The specific growth rate (µ) of the algal isolate was estimated by fitting a linear function to exponential phase of ln x(t) versus time curve, where x = biomass (mg/l) and t = time (days) 9 . For the control experiment, the algal inoculum of 1500 mg L −1 was inoculated to Erlenmeyer flask containing Fog’s medium and incubated under the same culture conditions as described above.…”

“…Keeping this in view, the petroleum industry requires to employ efficient and cost-effective technologies to reduce TPH in formation water below the permissible limit. Biodegradation encompassing its advantages of complete pollutant mineralization with no generation of secondary by-products that incurs additional treatment costs is currently being seen as an economic and eco-friendly technique for cleanup of hydrocarbon-polluted sites 9 . Hydrocarbon degrading bacterial strains are commonly applied for biological treatment of hydrocarbons.…”

Phycoremediation of phenol‐polluted petro‐industrial effluents and its techno‐economic values as a win‐win process for a green environment, sustainable energy and bioproducts

“…Das et al . (2016) reported also the increase in lipid content in presence of phenol as a carbon source for diatom BD1IITG, with high affinity toward phenol (K s 20·99 mg l −1 ), and better phenol tolerance (K i 90·24 mg l −1 ), and maximum specific growth rate µ max (0·4 day −1 ). The lipid productivity is also reported to increase by 26% during phenol phycoremediation by a well‐adapted and acclimatized Dunaliella salina (Cho et al .…”