Comparative study of biodegradation of Palm Oil Mill Effluent (POME) by Bacillus subtilis and Pseudomonas aeruginosa was studied for 16 days. Starch hydrolysis test was conducted on Bacillus subtilis and Pseudomonas aeruginosa to detect starch degradation and amylase potentiality. Clear zone of hydrolysis was observed which indicates the ability of both organisms to degrade the complex carbon ‘Starch’. The biodegradative activity of both organisms was determined using the Mineral Salt Medium inoculated with 1% POME. The turbidity of the inoculated sample increased from day 0 to day 16.the least being on the 4 th day and the highest turbidity was recorded on the 16 th day for each of the organisms. The least amylase activity was recorded on the 4th day of the biodegradation process by Pseudomonas aeruginosaas 19.50±0.50U/ml while highest amylase activity was recorded on the 16th day by Bacillus subtilis as 61.50 ±0.50U/ml. total viable count of bacterial isolates revealed that the highest Bacillus subtilis and Pseudomonas aeruginosa counts occurred on the 8th day as 2.01×1010±1.00 cfu/ml and 2.75×1010±1.50 cfu/ml respectively. The enzyme ‘Amylase’ produced by both organisms has the capability to breakdown molecules that are complex in nature and may be used for other purposes such food production and environmental protection and conservation. This study suggests that Bacillus subtilis grows and metabolize compounds in palm oil mill effluent to produce amylase better than Pseudomonas aeruginosa.
1.1 Background of Study
Oil palm (Elaeis guineensis) is a monoecious plant that bears both male and female flowers on the same tree. It belongs to the palmae family and is the most productive oil producing plant in the world (Panapaanet al., 2009). Palm trees may grow up to 60 feet or more in height. The trunks of young and adult plants are wrappedin fronds which give them a rough appearance. The older tree have smoother trunks apart from the marks left by the fronds which have withered and fallen off (Panapannan et al.,2009).
Each tree produces compact bunches of fruitlet weighing about 10 – 25kg with 1000 to 3000 fruitlets per bunch. Each fruitlet is spherical or elongated in shape. Generally, the fruitlet is dark purple (almost black) and the colour turns to orange red when ripe. The process of extracting palm oil requires significant large quantities of water to steam sterilize the palm fruit bunches clarify the extracted oil and for washing and cleaning processes in the mill.
The separated waste water sludge commonly referred to as palm oil milling effluent (POME) is a brown slurry, which is composed of 4- 5% solids (mainly organic), 0.5 – 1.0% residual oil and about 95% water and high concentration of organic nitrogen (Elijah et al., 2012). POME is a thick brownish liquid that contain solids, oil and grease, chemical oxygen demand (COD) and biological oxygen demand (BOD) (Panapanaan et al., 2009). Palm oil mills release POME in tremendous volumes with its attendant polluting potential. POME has adverse environmental impacts including land and aquatic ecosystem contamination and loss of biodiversity. Palm oil as a lipid derives its distinctive properties from the hydro carbon nature of a major portion of the structure. The molecules are composed mainly of long chain of carbon atoms. The hydrocarbon group is modified by the presence of small number of more reactive polar groups. The chain can exist in several forms but have long saturated and unsaturated monocarboxylic aliphatic free acids.
Since the major portion of a lipid is the hydrocarbon, some micro organism which utilizes hydrocarbon has the ability to grow and proliferate in it.
1.2 JUSTIFICATION OF THE STUDY
As of 2010, Nigeria was one of the top three producer of palm oil globally, with more than 2.5 million hectares (6.2 x 106acres) under cultivation. Until the early 1930’s the country had been the world’s largest producer of palm oil. These encompass both small and large scale producers. Palm oil cultivation has been criticized for impact on the natural environment by environmental activist groups. Palm Oil Mill Effluent (POME) is an important source of inland water pollution when released into local rivers or lakes without treatment. The production of palm oil however results in the generation of this Palm Oil Mill Effluent (POME) in large quantities.
This research work is aimed at studying the biodegradation of POME invitro to produce an enzyme (AMYLASE) using bacterial isolates. This enzyme is environmental friendly and cost effective which will serve as alternative to the chemical used for industrial processes
1.3. AIM OF STUDY
The aim of this work was to study comparatively, the invitro production of amylase by Pseudomonas species and Bacillus species,during the biodegradation Of Palm Oil Mill Effluents (POME).
1.4. OBJECTIVES OF THE STUDY
The Objectives of the Study includes:
- I. To collect POME sample from a local processing plant
- II. To obtain pure isolates of Bacillus subtilis and Pseudomonas aeruginosa
- III. To screen the pure isolates for amylase production
- To investigate the invitro biodegradability of Palm Oil Mill Effluent by Pseudomonas aeruginosa and Bacillus subtilis.
- V. To compare the various rate at which Pseudomonas aeruginosa and Bacillus subtilis degrade Palm Oil Mill Effluent(POME) invitro.
- To determine the activity of the enzyme (amylase) produced during the biodegradation of POME by the respective organisms at intervals