Application of one factor at a time (OFAT) and response surface methodology (RSM) for optimizing phenol-degrading parameter by isolate 1

Global warming has always been a great concern especially in Antarctica due to pollution. Phenol pollution is one of the well-known pollution that highly affects the ecosystem in Antarctic soil and water. Due to it being widely used in various industries, excessive phenol is discharged into rivers and soil which might affect living things. The purpose of this study is to optimise the conditions for phenol-degrading bacteria Isolate 1 to degrade phenol at low temperatures using one factor at a time (OFAT) approach and response surface methodology (RSM). Four major parameters that can affect phenol degradation are pH, nitrogen source, temperature and salinity. From OFAT approach, Isolate 1 was found to have a high capability to degrade phenol with an optimum pH of 7.5 in phosphate buffer, ammonium sulphate as its best nitrogen source with concentration of 0.40 g/L, temperature of 15°C and salinity of 0.10 g/L. Meanwhile, during optimisation using RSM, Isolate 1 shows the highest phenol degradation percentage through interaction between 2 factors which are salinity with optimum sodium chloride (NaCl) concentration of 0.15 g/L and pH of 7.65. The greatest achievement in RSM is that Isolate 1 which is classified as cold-tolerant bacteria can degrade 0.50 g/L phenol up to 98.32% within two days