Research
Microorganisms and Aflatoxin Content in Ready-to-Eat Groundnut Paste from some Markets in Anambra and Edo States, Nigeria
This study was undertaken to quantitatively and qualitatively estimate microbial and aflatoxin content in ready – to – eat groundnut pastes sold in some markets in Anambra and Edo States, Nigeria. A total of 100 samples of ready- to eat – groundnut pastes packaged in plastic cans and low density polyethylene were purchased from some marketsin Anambra State (Head Bridge, Ogbaru, Agulu, Mgbuka and Awka) and Edo State (Oba market, Santana, New Benin, Uselu and Oregbeni). The samples were analyzed microbiologically and physicochemically using standard procedures. Aflatoxin detection was done using Enzyme-Linked Immunosorbent Assay (ELISA). Bacteria species associated with the samples were identified as Staphylococcus aureus, Bacillus cereus , Bacillus subtilis, Micrococcus roseus, Esherichia coli and Pseudomonas aeruginosa while fungi include Aspergillus flavus, Aspergillus tamarii, Aspergillus niger, Aspergillus fumigates and species of Penicillium and Fusarium. Total bacterial count ranged from 2.50 ± 0.61 x 104 – 5.54 ± 0.50 x 104 cfu/g. Lowest bacterial count( 2.50 ± 0.61x 104 cfu/g) was obtained in Awka market while the highest(5.54 ±0.50 x 104 cfu/g) was from Oba market. The fungal counts ranged from 1.70 ± 0.99 x 103 – 5.60 ± 0.65 x 103 cfu/g with Uselu market having the lowest counts (1.70 ± 0.99 x 103 cfu/g) and Ogbaru market in Anambra State having the highest counts( 5.60 ± 0.65 x 103 cfu/g). Aflatoxin content of the samples ranged from 1.1± 0.07 – 143.9+ 2.72 ppb. The presence of pathogenic bacteria and aflatoxin in the ready-to-eat groundnut paste pose a potential health challenge to the consumers in some parts of Anambra and Edo States, Nigeria.
Degradation of Crude Oil by Bacteria: A Role for Plasmid-Borne Genes
The role of plasmid-borne genes in the biodegradation of Chevron Escravos Crude Oil by bacteria was determined. Plasmid extraction and curing, transformation experiments and biodegradation studies were carried out using standard procedures. Plasmid extraction studies showed that two of the six selected crude oil degrading bacterial isolates had two plasmids each. The isolates were Klebsiellaaerogenesfrom ripe pawpaw fruit and Serratiamarscescens from oil palm mill effluent. The plasmids were of small (300bp) and large (>1.5kbp) sizes. The results also showed that the isolates were successfully cured of plasmids using 1% Sodium Dodecyl Sulphate (SDS). The transformation experiment using the extracted plasmid DNA and competent Escherichia coli K12 DH1 cells was successful. The percentage degradation of crude oil at 37oC by E. coli K12 DH1 transformed with the plasmid DNA from Klebsiellaaerogeneswas 93.03% while that transformed with the plasmid DNA fromSerratiamarscescens degraded 76.97% of the crude oil. It was observed that loss of plasmids byKlebsiellaaerogenesand Serratiamarscescens did not lead to complete loss of their degradative abilities. It only resulted in reduction in their degradation potential. These findings showed that plasmid encoded genes play a role in crude oil degrading capability of bacterial isolates.
MYCOLOGICAL & PHYSICO-CHEMICAL QUALITY OF WHEATEN WHITE BREAD FLOUR MADE FOR NIGERIAN MARKET
Mycological and physico-chemical quality of wheaten white bread flour, made for Nigerian market was examined at room temperature of storage for 120days (about four months). During storage, total fungal count was above the maximum acceptable limit of 100 cfu per gram white bread flour. Fungal counts increased towards the end of the storage period but no significant difference of fungal count was noticed during storage. Also slight ecological succession was noticed amongst the various groups of fungi. The fungal isolates from this study were species of Penicillium, Rhizopus, Mucor, Geotricum, Oidium, and Saccharomyces. Three of the four brands of flour analysed had a pH of below 6.0 on the 105th day of the study. The ash content of the various brands of flour was above 0.65% recommended for flour with effect from day 90 of storage. Protein, gluten, fat, moisture, and carbohydrate contents were within the acceptable limit values for flour. The public health implications of these findings are hereby discussed.
