Isolation and characterization of phenol degrading bacterium strainBacillus thuringiensisJ20 from olive waste in Palestine

Abstract

This study aimed at isolation of phenol degrading bacteria from olive mill wastes in Palestine. The efficiency of phenol removal and factors affecting phenol degradation were investigated. A bacterial strain (J20) was isolated from solid olive mill waste and identified as Bacillus thuringiensis based on standard morphological, biochemical characteristics and 16SrRNA sequence analysis. The strain was able to grow in a phenol concentration of 700 mg/L as the sole carbon and energy source. The culture conditions showed a significant impact on the ability of these cells to remove phenol. This strain exhibited optimum phenol degradation performance at pH 6.57 and 30 °C . Under the optimized conditions, this strain could degrade 88.6% of phenol (700 mg/L) within 96 h when the initial cell density was OD 0.2. However, the degradation efficiency could be improved from about 88% to nearly 99% by increasing the cell density. Immobilization of J20 was carried out using 4% sodium alginate. Phenol degradation efficiency of the immobilized cells of J20 was higher than that of the free cells, 100% versus 88.6% of 700 mg/L of phenol in 120 h, indicating the improved tolerance of the immobilized cells toward phenol toxicity. The J20 was used in detoxifying crude OMWW, phenolic compounds levels were reduced by 61% compared to untreated OMWW after five days of treatment. Hence, B. thuringiensis-J20 can be effectively used for bioremediation of phenol-contaminated sites in Palestine. These findings may lead to new biotechnological applications for the degradation of phenol, related to olive oil production.

Optimized parameters using Box–Behnken design methodology facilitate enhanced phenol degradation of Bacillus cereus PB1 by immobilization and adsorption

“…The result coincides with those of Ereqat et al. (2017), who have also found that the optimal temperature was 30°C for Bacillus thuringiensis J20, and increasing the temperature from 25°C to 30°C increases the percentage of degradation of phenol, ranging from 74.5% to 88.6%, while increasing the temperature above 30°C, the phenol degradation was about to decrease from 88.6% to 62.1%. Similarly, Shah (2018) recorded the temperature of 30°C as optimum for phenol removal of 78.69% by indigenous P. mendocina .…”

Biodegradation of Phenol by Curtobacterium flaccumfaciens: Optimization of Growth Conditions

“…To our awareness, this is the initial study linked to biodegradation of the phenol compound by Curtobacterium. In fact, although the biodegradation of phenol compounds by microorganisms is argued exceedingly in the literature [16,24,25], no investigations involving Curtobacterium have been published. C. flaccumfaciens was capable to…”

“…Although highly acclimatized to phenol, the bacteria showed an extended lag phase because of the high phenol concentration. Most of the studies pertaining to bacterial metabolism of phenol was aerobically performed, oxygen is used by the phenol hydroxylase enzyme for adding a second hydroxyl group [1,15,16]. During biodegradation of aromatic compounds as growth substrates they transformed to dihydroxy derivatives of either ortho or para before ring cleavage.…”

Bioremediation of Copper‐Ions by Polymer Encapsulated and Immobilized Micrococcus Luteus

“…The mechanism with microorganisms is based on the change from oxidative state or complex to another state (valance transformation), volatilization, and extracellular chemical precipitation. [ 4–9 ] Bacteria are confessed as the most abundant microorganisms in the ecosystem with a high surface to volume ratio. [ 10 ] The bioremediation efficiency is depending not only on the ambient conditions, such as pH and temperature, but also to the type of bacteria.…”