224
nutrients, and oil degrading organisms like Thalassolituus and Alcanivorax reflected
a synergistic effect, ensuing more degradation of n-alkanes (73%), branched alkanes
(59%), and polynuclear aromatic hydrocarbons (28%) in the initial 5 days of biodegradation processes. Similarly, Nikolopoulou and Kalogerakis (2008) demonstrated the efficacy of addition of fertilizers possessing nitrogen and phosphorus to
remediate oil spills (96% removal of C 19 –C 34 n-alkanes) in marine environments. In
a recent study, Lee et al. (2018) reported some indigenous biosurfactant-producing
bacteria which notably desorbed crude oil in oil-contaminated marine sediments.
8.3 Role of Biosurfactants in Bioremediation
of Polyaromatic Hydrocarbons
Polyaromatic hydrocarbons can be defined as the organic pollutants primarily formed
due to the incineration of fossil fuels. They are considered as one of the most hazardous contaminants owing to their perseverance, toxic, mutagenic, and carcinogenic
nature (Cerniglia 1992). Physicochemical and biological factors influence the rate of
biodegradation. The capability of hydrophobic compounds to be dissolved and transported into microbial cells which can metabolize them constitutes the rate- limiting
step in the process of bioremediation. Noordman and Janssen (2002) investigated the
efficacy of rhamnolipids for enhanced removal of phenanthrene using rhamnolipid
solution (500 mg/L) and reported that removal of phenanthrene was enhanced (two–
fivefold shorter time required for 50% recovery and 3.5-fold for 90% recovery) in
contrast to controls. In addition, Sphingomonas paucimobilis EPA505 produced
Alasan biosurfactant which increased the rate of phenanthrene mineralization
(Barkay et al. 1999). Likewise, it was found that fluoranthene served as sole source
of carbon in Sphingomonas paucimobilis EPA505 (Kanaly and Harayama 2000).
Some marine bacteria, for instance, Cycloclasticus spirillensus, Lutibacterium
anuloederans, and Neptunomonas naphthovorans, were previously used in improved
biodegradation of PAHs in marine ecosystem (Chung and King 2001).
Similarly, Samanta et al. (2002) reported naphthalene-degrading marine bacteria
including Achromobacter denitrificans, Bacillus cereus, Corynebacterium renale,
Cyclotrophicus sp., Moraxella sp., Mycobacterium sp., Burkholderia cepacia,
Pseudomonas fluorescens, Pseudomonas paucimobilis, P. putida, Brevundimonas
vesicularis, Comamonas testosteroni, Rhodococcus sp., Streptomyces sp., and
Vibrio sp. However, Teramoto et al. (2011) opined that bacteria in the genus
Oleibacter marinus have key role in biodegradation of hydrocarbons. A biosurfactant from marine Bacillus circulans was reported to enhance the availability and
biodegradation of anthracene (Das et al. 2008). Bezza and Chirwa (2015) reported
improved biodegradation of used motor oil polycyclic aromatic hydrocarbon compounds up to 82% in 18 days of incubation using a lipopeptide produced by Bacillus
subtilis CN2. More recently, biosurfactant produced by Ochrobactrum intermedium
collected from crude oil-contaminated soil efficiently solubilized naphthalene and
phenanthrene (Ferhat et al. 2017).
K. V. Deepika et al.
nutrients, and oil degrading organisms like Thalassolituus and Alcanivorax reflected
a synergistic effect, ensuing more degradation of n-alkanes (73%), branched alkanes
(59%), and polynuclear aromatic hydrocarbons (28%) in the initial 5 days of biodegradation processes. Similarly, Nikolopoulou and Kalogerakis (2008) demonstrated the efficacy of addition of fertilizers possessing nitrogen and phosphorus to
remediate oil spills (96% removal of C 19 –C 34 n-alkanes) in marine environments. In
a recent study, Lee et al. (2018) reported some indigenous biosurfactant-producing
bacteria which notably desorbed crude oil in oil-contaminated marine sediments.
8.3 Role of Biosurfactants in Bioremediation
of Polyaromatic Hydrocarbons
Polyaromatic hydrocarbons can be defined as the organic pollutants primarily formed
due to the incineration of fossil fuels. They are considered as one of the most hazardous contaminants owing to their perseverance, toxic, mutagenic, and carcinogenic
nature (Cerniglia 1992). Physicochemical and biological factors influence the rate of
biodegradation. The capability of hydrophobic compounds to be dissolved and transported into microbial cells which can metabolize them constitutes the rate- limiting
step in the process of bioremediation. Noordman and Janssen (2002) investigated the
efficacy of rhamnolipids for enhanced removal of phenanthrene using rhamnolipid
solution (500 mg/L) and reported that removal of phenanthrene was enhanced (two–
fivefold shorter time required for 50% recovery and 3.5-fold for 90% recovery) in
contrast to controls. In addition, Sphingomonas paucimobilis EPA505 produced
Alasan biosurfactant which increased the rate of phenanthrene mineralization
(Barkay et al. 1999). Likewise, it was found that fluoranthene served as sole source
of carbon in Sphingomonas paucimobilis EPA505 (Kanaly and Harayama 2000).
Some marine bacteria, for instance, Cycloclasticus spirillensus, Lutibacterium
anuloederans, and Neptunomonas naphthovorans, were previously used in improved
biodegradation of PAHs in marine ecosystem (Chung and King 2001).
Similarly, Samanta et al. (2002) reported naphthalene-degrading marine bacteria
including Achromobacter denitrificans, Bacillus cereus, Corynebacterium renale,
Cyclotrophicus sp., Moraxella sp., Mycobacterium sp., Burkholderia cepacia,
Pseudomonas fluorescens, Pseudomonas paucimobilis, P. putida, Brevundimonas
vesicularis, Comamonas testosteroni, Rhodococcus sp., Streptomyces sp., and
Vibrio sp. However, Teramoto et al. (2011) opined that bacteria in the genus
Oleibacter marinus have key role in biodegradation of hydrocarbons. A biosurfactant from marine Bacillus circulans was reported to enhance the availability and
biodegradation of anthracene (Das et al. 2008). Bezza and Chirwa (2015) reported
improved biodegradation of used motor oil polycyclic aromatic hydrocarbon compounds up to 82% in 18 days of incubation using a lipopeptide produced by Bacillus
subtilis CN2. More recently, biosurfactant produced by Ochrobactrum intermedium
collected from crude oil-contaminated soil efficiently solubilized naphthalene and
phenanthrene (Ferhat et al. 2017).
K. V. Deepika et al.