Selected Metal (Fe, Cu and Zn) Levels in Fish and Water at Abaya and Chamo Rift Valley Lakes
Dugasa Gerenfes,
Endale Teju,
Tesfahun Kebede
Issue:
Volume 4, Issue 2, March 2019
Pages:
17-27
Received:
18 January 2019
Accepted:
9 May 2019
Published:
24 June 2019
Abstract: Samples of fish organs and water were collected from three sampling sites of Lakes Chamo and Abaya. A procedure consuming 12 mL mixture of HNO3-H2O2 for gill, kidney, liver and 1:2.5 mL mixture of HNO3-HCl for water samples for digestion of was developed. Concentrations of three metals in water and their accumulation in Tilapia (Oreochromis niloticus) and Barbus (Labeobarbus intermedius) fish species were determined using Flame Atomic Absorption Spectroscopy. Concentrations of metals in gills, kidney, liver and water varied (mg/kg): Zn 0.061-0.083, 0.047-0.076, 0.070-0.074, 0.011-0.024, respectively; Cu; 0.025-0.031, 0.028-0.043, 0.029-0.044, 0.023-0.092, respectively; Fe 2.934-3.583, 2.735-3.628, 0.809-2.723, 4.756-10.240, respectively. Most of the elements in water samples occurred below detection limit. The highest accumulations of iron (Fe) concentration were observed in liver and gill of Tilapia fish from Chamo Lake. Among the detected metals, zinc (Zn) showed the maximum bioaccumulation factor in both fish species from both lakes, while iron was the least bio accumulated metallic species. Using Pearson correlation, positive correlation was observed for the specific fish organ with water samples. There was no significant difference between the two lakes in accumulating trace metals however lake chamo had higher concentration.
Abstract: Samples of fish organs and water were collected from three sampling sites of Lakes Chamo and Abaya. A procedure consuming 12 mL mixture of HNO3-H2O2 for gill, kidney, liver and 1:2.5 mL mixture of HNO3-HCl for water samples for digestion of was developed. Concentrations of three metals in water and their accumulation in Tilapia (Oreochromis nilotic...
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Evaluation of OGI (CORN CARAMEL) from Maize and Sorghum for Isolation and Characterisation of Lactic Acid Bacteria (LAB)
Akin-Osanaiye Bukola Catherine,
Kamalu Ikechukwu Okechi
Issue:
Volume 4, Issue 2, March 2019
Pages:
28-34
Received:
15 April 2019
Accepted:
2 June 2019
Published:
29 June 2019
Abstract: Isolation and characterisation of Lactic Acid Bacteria (LAB) associated with the fermentation of maize and sorghum for the production of ogi were evaluated for the development of starter cultures. Changes in pH and LAB counts were investigated during the cereal based-product fermentation. A decrease in pH was observed during the natural fermentation from 0hr to 48hrs. The LAB were isolated, characterised and identified using cultural, morphological and physiological methods. The isolates were: Lactobacillus plantarum, Lactococcus lactis, Lactobacillus acidophilus, Lactobacillus cellobiosus, Lactobacillus delbrueckii subsp. bulgaricus and Lactobacillus casei. The isolates from maize–produced ogi were capable of growing on sterilised maize grains, with Lactobacillus plantarum having the highest potential as a starter culture for ogi production from maize. Also, the isolates from sorghum-produced ogi were capable of growing on sterilised sorghum grains, with Lactobacillus delbrueckii subsp. bulgaricus having the higher potential as starter culture for ogi production from sorghum. Sterilised maize grains inoculated with pure culture of Lactobacillus plantarum showed the highest counts of 2.1 × 108 at 24 hrs of fermentation than the other Lactic Acid Bacteria. In the same vein, sterilised sorghum grains inoculated with pure culture of Lactobacillus delbrueckii subsp. bulgaricus showed the higher counts of 1.12 × 108 at 24 hrs of fermentation than the other Lactic Acid Bacterium. There was no significant difference (p ≤ 0.05) in the mean of the pH values obtained during the spontaneous fermentation of maize and sorghum. The results obtained indicated that all the six LAB isolates could be used singly as starter cultures to produce ogi within a shorter fermentation period.
Abstract: Isolation and characterisation of Lactic Acid Bacteria (LAB) associated with the fermentation of maize and sorghum for the production of ogi were evaluated for the development of starter cultures. Changes in pH and LAB counts were investigated during the cereal based-product fermentation. A decrease in pH was observed during the natural fermentatio...
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