Bacillus consortium to degrade crude oil in aerobic static cultures under laboratory
conditions (Perera et al. pers. Comm).
Temperature influences the chemical and physical structures of the PH components; higher temperatures will increase solubility of the hydrocarbons and decrease
viscosity, thus increasing bioavailability of the PH to the microbes. Temperature will
also affect the growth rate of the microbes as well as the rate of enzyme activity (Bell
and Gutierrez 2019). Extremophiles have been reported to degrade hydrocarbons at
temperatures of 60
C (Loginova et al. 1981), while psychrophilic bacteria may
degrade PH at temperatures as low as 5–13
C (Ribicic et al. 2018).
11.8.2 Nutrients
The availability of nutrients plays a crucial role in microbial biodegradation of
hydrocarbons, with the growth of the organisms often being affected by low levels
of nitrogen and phosphorous. The formation of oil slicks on the water surfaces has
been observed to lead to depletion of nutrients on the surface.
11.8.3 pH
The pH of the environment will affect the enzyme activity and cell membrane
transport in microorganisms, consequently affecting the rate of biodegradation.
Neutral or alkaline pH has been shown to be suitable for PH degradation (Cui
et al. 2019).
11.8.4 Oxygen
Molecular oxygen is the optimal electron acceptor for aerobic biodegradation of
petroleum hydrocarbons and has been identified as the rate-limiting variable in PH
degradation (Varjani and Upasani 2017). It is also frequently the substrate in the
initial reaction of PH degradation, in reactions that are catalyzed by
monooxygenases. Increasing air flow up to 2.0 L/h was observed to be beneficial
for PH degradation in a bioreactor, but above that there was little change in
efficiency (Cui et al. 2019).
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S. Jayasena and M. Perera
conditions (Perera et al. pers. Comm).
Temperature influences the chemical and physical structures of the PH components; higher temperatures will increase solubility of the hydrocarbons and decrease
viscosity, thus increasing bioavailability of the PH to the microbes. Temperature will
also affect the growth rate of the microbes as well as the rate of enzyme activity (Bell
and Gutierrez 2019). Extremophiles have been reported to degrade hydrocarbons at
temperatures of 60
C (Loginova et al. 1981), while psychrophilic bacteria may
degrade PH at temperatures as low as 5–13
C (Ribicic et al. 2018).
11.8.2 Nutrients
The availability of nutrients plays a crucial role in microbial biodegradation of
hydrocarbons, with the growth of the organisms often being affected by low levels
of nitrogen and phosphorous. The formation of oil slicks on the water surfaces has
been observed to lead to depletion of nutrients on the surface.
11.8.3 pH
The pH of the environment will affect the enzyme activity and cell membrane
transport in microorganisms, consequently affecting the rate of biodegradation.
Neutral or alkaline pH has been shown to be suitable for PH degradation (Cui
et al. 2019).
11.8.4 Oxygen
Molecular oxygen is the optimal electron acceptor for aerobic biodegradation of
petroleum hydrocarbons and has been identified as the rate-limiting variable in PH
degradation (Varjani and Upasani 2017). It is also frequently the substrate in the
initial reaction of PH degradation, in reactions that are catalyzed by
monooxygenases. Increasing air flow up to 2.0 L/h was observed to be beneficial
for PH degradation in a bioreactor, but above that there was little change in
efficiency (Cui et al. 2019).
284
S. Jayasena and M. Perera