Journal of Advances in Biology & Biotechnology

Fish is an extremely perishable food item and requires preservation for future use. Several methods including drying, are used round the world for preserving fish and to extend its shelf-life. The microbial quality of sun-dried fish locally called “soudamouka” was investigated. Commercially available “soudamouka” samples were collected from retailers within the Far North region of Cameroon. Three different retailers (S1, S2 and S3) were sampled, then, the collected samples were screened for their microbial load. The highest level of Escherichia coli (62.10⁴ cfu.g^-1) was recorded in S3 soudamouka sample while the lowest count (5.10² cfu.g^-1) was obtained in S1 soudamouka. The fungal load varied from 0, 1.10² to 5.10² cfu.g^-1 while the C. perfringens load for different samples were found to be S1 = 16.10⁴ cfu.g^-1, S2 = 20.10⁴ cfu.g^-1 and S3 = 55.10 ⁴cfu.g^-1. These high microbial loads and presence of pathogens could be attributed to the poor handling practices and storage temperature by retailers. Although, drying may reduce water activity and consequently microbial load, post processing contamination may occur during post handling and transportation of processed fish to the sale points.

Filamentous fungi have been widely utilized in production of enzymes which have many industrial applications. In this study, twenty five local fungal isolates, belonging to Aspergillus sp., Trichoderma sp. and Penicillium sp., were screened under solid state fermentation conditions (SSF) for the production of α-amylase, glucoamylase and cellulase. Asperigillus oryzae F-923, cultivated on wheat bran, was the most promising isolate for production of the target enzymes under this study. Physical parameters of moisture content, pH, temperature and incubation time, optimized were 1:2(w/v), 5.5, 28°C and 72 hr, respectively. The production of enzymes was enhanced when ammonium sulfate was supplemented as a nitrogen source to wheat bran. The production of α-amylase and glucoamylase was also enhanced when 10% (w/w) soluble starch was added as a carbon source to wheat bran. However xylose supplementation at 10% (w/w) was observed to be best for cellulase production. Tap water was found to be efficient for enzymes' extraction from the fermentation medium. Three successive extractions were needed to obtain the produced enzymes from the fermented substrate. Characterization of the produced enzymes revealed that, the optimum temperature for α-amylase and glucoamylase was 60°C, while 50°C was the optimum temperature for cellulase activity. Isopropanol 1:1(v/v) was proved to be more suitable for partial purification of enzymes. Following partial purification of enzymes of glucoamylase, α-amylase and cellulase increased to 10.8, 11.8 and 11.4 folds, respectively.

Aim: The study assessed the bio treatability of the petroleum refinery sludge in contaminated soils by indigenous bacterial communities and the effects of the sludge contamination and bio stimulants on the biodiversity and dynamics (rate of change) of the bacterial communities involved in the biodegradation of the sludge, using the molecular biology technique, Denaturing Gradient Gel Electrophoresis (DGGE).

Study Design: The randomnized block design was used for the study.

Place and duration of the Study: The research was conducted in the biology laboratory of Flinders University, Adelaide, South Australia.

Methodology: The percentage of total petroleum hydrocarbons (TPH) degraded and the bacterial load in the test microcosms was assessed tri-weekly for 12 weeks. The percentage TPH was assessed using Gas chromatography, while the bacterial count was determined as gene copies using the culture independent molecular tool, quantitative real-time PCR (qRt-PCR) analysis. The effects of the experimental treatments on the biodiversity and dynamics (rate of change) of the bacterial communities involved in the biodegradation of the sludge in the soils was determined by the culture-independent molecular biology technique, DGGE. Moving Windows Analysis (MWA) and Shannon Weaver diversity index were used to determine the dynamics (rate of change) and biodiversity of the bacterial communities respectively.

Results: Results obtained for the Moving Window Analysis (MWA) which is used to determine the dynamics (Dy), or rate of change of the bacterial communities, showed that, the 1% and 5% sludge contaminated soils biostimulated with compost, recorded the highest Dy of 86.0 ± 1.90% and 87.0 ± 2.20% respectively.NPK biostimilated soil microcosms however recorded a lower Dy of 33.75± 3.20 and 32.50 ± 4.68% for 1% and 5% sludge contamination respectively. The biodiversity of the bacterial communities expressed as Shannon -Weaver index (H¹), recorded the highest value of 2.76 ±0.02 for the compost biostimulated microcosm in the 1% sludge treatment, while for the 5% sludge contamination, the treatment with NPK and surfactant enhanced the bacterial biodiversity most with a value of 2.76 ±0.07%. In the test soils with 1% sludge contamination, bio stimulation with NPK gave the highest % TPH degradation (78.25%) while the treatment with NPK and Triton-X 100 had the highest TPH degradation (46.55%) for the 5% sludge contaminated soils. There was insignificant difference in the % sludge degradation between the control and other treatments at P > 0.05 and F = 4.07 for the 1% sludge treated soils, while for the soils treated with 5% sludge there was significant difference between the control and other treatments at P < 0.05 and F= 4.07.

Conclusion: Bacteria species identified in the sludge by molecular biology techniques included; Pseudomonas sp. ITRI77, Uncultured Thauera sp., Uncultured Pseudomonas sp., Flavobacterium sp., Bacillaceae bacterium, Uncultured soil bacterium, Clostridium sp., most of which are Gram negative. Biostimulation with compost enhanced a higher biodiversity (H ⁱ) and dynamics (Dy) of the bacterial communities involved in the biodegradation of the sludge. Though the NPK treated soils enhanced the biodegradation of the sludge most, degradation started declining by the 9^th week while that of compost continued to rise steadily till the 12^th week. Results obtained indicate that compost is as good as NPK in the biodegradation of petroleum sludge especially at 1% sludge contamination, since there was no statistical difference between the % TPH degraded and the use of compost is environmentally friendly and economically sustainable.

Aims: To investigate the anti-oxidant activity of the nhexane extracts of Caryota no seeds in D. melanogaster.

Study Design: Experimental design.

Place and Duration: Sample: African Centre of Excellence for Phytomedicine Research and Development, University of Jos, Jos Plateau State Nigeria between June 2018 and February 2019.

Methodology: Total protein assays were carried out by exposing 50 flies in each vial to the following concentrations: 300 mg, 350 mg, 400 mg, 500 mg and 600 mg of nhexane extracts in 5 replicates for 7 days with daily recording of mortality. In vivo antioxidant activity study was conducted by measuring levels of Glutathione-S-Transferase (GST), catalase (CAT) and total thiol (TT) from supernatants of whole fly homogenates using a spectrophotometer at specific wavelenghts. The values were derived as part of the total protein value. The statistical difference among test groups was presumed at P <0.05.                                   

Results: The nhexane extract of CN caused nonsignificant (P = .52) changes in total protein levels compared to the control. The antioxidant activity showed nonsignificant (P = .64) higher total thiol contents and GST (P = .76) activity in nhexane extract-treated flies and lower catalase (P = .30) activity was recorded in the nhexane extract-treated flies compared to the controls.

Conclusion: It can therefore be concluded that the nhexane extract of Caryota no possess appreciable concentrations of different types of antioxidants.

Envenomation is a serious public health and occupational hazard in tropical and subtropical countries. Antivenom serum treatment has been related to extreme hypersensitivity, high cost, and inaccessibility. Consequently, therapeutic plants have been investigated to give an alternative treatment. The aim of this study was to evaluate the ability of the methanolic extract and fractions of Tamarindus indica seeds to neutralize the hemolytic, anticoagulant and hemorrhagic activities of Bitis arietans venom. The powdered form of Tamarindus indica seed was extracted using methanol. The methanol extract was further fractionated using butanol solvent. The aqueous fraction of the methanolic extract inhibited hemolysis caused by crude venom by 95.5%, while methanolic extract significantly reduced the anticoagulant time of crude venom to 10.2%. The in vivo hemorrhagic activity of the crude venom of Bitis arietans was neutralized by both the crude methanolic extract and the subsequent two fractions of Tamarindus indica seed. However, the crude methanolic extract was found to be the most active by reducing the hemorrhage diameter caused by crude venom to 39%. The findings of this present research work demonstrated a very good antivenom properties of the seeds of Tamarindus indica, which suggests that it could be a potential source of effective, and safe compounds with inhibitory activities against Bitis arietans envenomation.