Lipolytic Activity and Molecular Identification of Pseudomonas aeruginosa and Lysinibacillus sphaericus Isolated from Domestic Oil Rich Wastewater.

Microbial lipases have been heightened in bioremediation and various industries. Place and Duration of Study: Department of Microbiology, Ekiti State University, Ado-Ekiti, Ekiti State, Nigeria, between September 2010 and August 2011. To identify the lipolytic enzyme producing microbial strains in domestic oil rich wastewater, the 16S rRNA gene was amplified and sequenced. The sequences were used to identify the strains by comparing with related sequences in database using BLAST analysis. The enzyme activity was quantified by HPLC analysis. All the lipolytic bacteria showed appreciable growth rates in the wastewater (between 0.67 and 1.67 mg/day) within 5 days. The most effective lipolytic bacteria isolates in the oil-rich wastewater were two species of the genus Pseudomonas and one of Bacillus. Comparing the weights on the first day to the twelfth day values when lipolytic organisms were grown in palm oil, some appreciable increases in weight difference were recorded in some isolates: 28.3%, 7.84%, 4.44% and 6.98% for Pseudomonas, Staphylococcus, Bacillus and Klebsiella, respectively. The weight increase of each of the microbial cells in palm oil culture was usually lesser than what was obtained in the oil-rich wastewater culture. Two isolates showed high similar sequence (99%) to that of Pseudomonas aeruginosa and Lysinibacillus sphaericus, respectively. From palm oil, Lysinibacillus sp. produced various forms of fatty acids in the medium, including myristic acid (2.61%), palmitic acid (6.22%), stearic acid (5.18%) and arachidic (3.66%). These strains are versatile in utilizing the limited nutrient and had the ability to grow appreciably in the toxic condition (soap solution), suggesting that they may serve as candidates in treating dietary oil-rich wastewater.

In vitro Antibacterial Activity of Aqueous Extracts of Cashew (Anacardium occidentale L.) Fruit Peels Using Bioautography Method.

Aims: Bark, leaves and gum of cashew (Anacardium occidentale L.) have been reported to be effective in curtailing the growing problems of resistance of bacterial pathogens. The in vitro activity of aqueous extracts of cashew apple peels was determined in this study against two clinically important pathogens. Place and Duration of Study: The work was conducted at the Department of Microbiology, Ekiti State University, Ado-Ekiti, Nigeria and processed immediately. This study was carried out between June, 2009 and January, 2010. Methodology: Bioautographic method was used to test the antibacterial activity of aqueous (cold and hot water) extracts of cashew apple peels on Escherichia coli O157:H7 and methicillin-resistant Staphylococcus aureus (MRSA). The zones of inhibition of the extracts were compared. Results: The activity of the fifth hour hot water extract was highest with zones of inhibition of 415.48 and 346.30 sq. mm against E. coli O157:H7 and MRSA respectively. E. coli O157:H7 was more susceptible to the extract with the zone of inhibition ranging between 176.79 and 283.53 sq. mm while that of MRSA was153.94 - 346.30 sq. mm. The 5 h extract of cold water was more potent on the test organisms with 615.75 and 490.87 sq. mm diameters of inhibition on E. coli O157:H7 and MRSA respectively. Cold water extracts produced more active compounds (13 biologically active spots) that inhibited the growth of the test organisms than the hot water extracts, with six spots. Conclusion: The extracts of the peels of the cashew apple against the test organisms are promising. However, the nature and mechanisms of action of the biologically active compounds in the extracts are still open to investigation.

In vivo Evaluation of Hypolipidemic Potentials of Bacillus Species Isolated from Fermented Locust Bean (Parkia fillicoides Welw) Seeds (Iru).

Aim: Iru is a popular West Africa fermented soup condiment which is also consumed without cooking as snack. This product is mainly fermented by Bacillus species. The hypolipidemic activities of Bacillus spp. isolated from iru have not been documented hence the aim of this study. Place and Duration of Study: Iru sample was bought in an open market in Iworoko-Ekiti, Nigeria and transferred to the Laboratory of the Department of Microbiology, Ekiti State University, Nigeria where other studies were carried out. The study was conducted between January and June, 2012. Methodology: The properties and in vivo hypolipidemic potential of Bacillus species from iru were investigated using standard microbiological and haematological methods. Results: The cell free extracts of the Bacillus spp. did not produce significant inhibition on the selected Gram positive and Gram negative pathogens. Qualitative enzyme screening of the isolates showed all were haemolysin negative. Only B. subtilis was positive to gelatinase while all the isolates produced catalase and lipase. The average weight of the animals after inducement of hyper-cholesterolemia ranged between 60.5g - 95.3g. The amount of serum total cholesterol (TC) in the animals ranged between 124.9 mg/dl – 127.4 mg/dl while that of serum triglycerides (TG), high density protein (HDL) and low density protein (LDL) were 122.5 – 155.3 mg/dl, 10.0 – 15.3 mg/dl and 76.6 – 81.0 mg/dl respectively. The weights of hyper-cholesterolemia induced rats challenged with different species of Bacillus were relatively lower than those in the control group and also differ significantly from the control, at p˂ 0.05. The values of TC, TG, and LDL were highest in the control (saline) group while the values in the treatment group ranged between 121.3 ± 1.5 and 102.3 ± 6.8 mg/dl for TC. The treatment groups recorded lower values of values for TG (104.7 ± 1.6 - 117.4 ± 9.1 mg/dl) and LDL (42.6 ±7.4 - 59.0 ± 10.2 mg/dl) compared to the control. B. subtilis had the highest values of TC but least amount of LDL. TG in all the groups was higher than TC, HDL and LDL. The TC/HDL and the LDL/HDL of the animals in the iru group was higher than the other treatment groups but lower than the control. Conclusion: Compared to the control, hypolipidemic activities of B. lichenliformis was the best followed by B. subtilis. Iru had the least hypo-cholesterolemic effect.