Isolation and identification of phytase-producing Bacillus and Enterobacter species from Nigerian soils

The bioavailability of phosphorus and other nutrients in feed for monogastrics is restricted by the presence of phytate. Exogenous supply of phytase produced by bacteria and other microbes can enhance the bioavailability of these nutrients and reduce phosphorus pollution. The objective of the study was to isolate bacteria with phytase-producing potentials from soil; which may be employed for the bioavailability of phosphorus and other nutrients in feed for monogastrics in Nigeria. Top soil samples were collected from two dumpsites in Lagos, Nigeria and bacteria were isolated and screened for potentials to produce phytase. The isolates with phytase potential were primarily identified by their cultural and biochemical  characteristics and then confirmed using the 16S rRNA sequencing, after which their expressed phytases were quantified. A total of six isolates  belonging to three species were identified as phytase producers. Sequence data analyses revealed these to be Bacillus subtilis (2), Bacillus  amyloliquefaciens (3) and Enterobacter cloacae (1) with accession numbers MH879827 and MH879832; MH879828, MH879830 and MH879831; and MH879829 respectively. Phenotypic phytase activity was highest in E. cloacae ODS 29 (9.69 ± 0.04 U/ml) and least in B. subtilis ODS 10 (8.83 ± 0.02 U/ml). In conclusion, phytase-producing Bacillus and Enterobacter species were isolated and characterized from Nigerian soils. These bacteria species could be used in biotechnological applications. Keywords: Bacillus, Enterobacter, Monogastrics, Phylogenetic analysis, Phytas

Influence of processing methods on the quality attributes of bio-fortified sweet potato products

Bio-fortified sweet potato (BSP) is one of the crops that can be used to address the problems of vitamin A deficiency in the Sub-Saharan Africa but it’s currently being underutilized. This study seeks to evaluate the effects of different heat processing methods on the quality of products made from BSP in order to increase its utilization. Freshly harvested tubers were purchased from a Research Farm in Federal University of Agriculture, Abeokuta (FUNAAB), Nigeria and brought to the Processing Centre, Nigerian Stored Products Research Institute (NSPRI), Ilorin. The sample was taken through some standard pre-processing operations of sorting, peeling, washing, slicing (2.11 mm), and deep frying (3 minutes) while some portions were boiled immediately after sorting with or without skin for 10–15 minutes. Each treated sample was analysed for sensory, proximate, vitamins and mineral compositions following standard methods. Results showed that fried sample had highest acceptability for aroma (7.25) and crispiness (7.00) while sample boiled without skin (15 min) was rated with least scores in colour (5.30), appearance (5.40), texture (4.95), crispiness (4.65) and overall acceptability (5.70). Protein, vitamin C, phenolics, flavonoids and reducing sugar contents were 6.53–18.52%, 10.89–76.69 mg/100 g, 0.57–3.15 mg/L, 94.64–383.91 mg/L and 43.05–237.12 g/100 g respectively while some minerals such as Na, K and Zn ranged from 8.42–17.45, 5.12–9.30 and 0.03–0.09 mg/L respectively. Different heat processing at different durations affected the sensory attributes, nutritional and mineral compositions of BSP. Key words: Post-harvest, food security, potato, heat treatment, qualit

Hepatoprotective and therapeutic potential of liver Gen® on carbon tetrachloride induced liver damage in female Wistar albino rats

Background: Liver gen , a Chinese herbal productwith claims of potency against a variety of diseaseconditions is commonly sold and used in every part ofNigeria by people plagued with ill health.Objective: The study evaluated the hepatoprotectiveeffect, therapeutic potentials and acute toxicity of®Liver gen on carbon tetrachloride induced liverdamage in female Wistar albino rats.Materials and methods: Acute toxicity study wascarried out using albino mice and the LD for Liver 50®gen determined. Similarly, albino rats weighing 180-200g were divided into four groups. Hepatic injury inrats was induced in groups I – III by the administrationof equal mixture of Carbon tetrachloride (CCL ) and 4olive oil (50% v/v, 1ml / kg body weightintraperitoneally) every 72 hours for 10 days. Group I(negative control) was not treated while groups II and®III were subsequently treated with Liver genadministered orally at a dose of 28.6mg / kg and57.2mg / kg body weight respectively for 14 days.Group IV (normal control) received distilled waterthroughout the study period. After the treatmentperiod the animals were sacrificed, serum wasobtained from the blood; liver, brain and kidney wereexcised. Employing standard biochemical assayprotocols, hepato-specific biomarkers, alanine aminotransferase (ALT), aspartate amino transferase(AST), alkaline phosphatase (ALP), renal functionstest (urea and creatinine), hematological indicessuch as hemoglobin (Hb) concentration packed cellvolume (PCV) and white blood cell count (WBC) weredetermined in the serum. Antioxidant statussuperoxide dismutase (SOD), catalase (CAT),reduced glutathione (GSH), malondialdehyde (MDA)and histopathological features were assessed in therat tissues. Heavy metals' contamination wasassessed in the product using atomic absorptionspectroscopy.Results: Levels of liver function marker enzymesalanine amino transferase (ALT) decreased (p<0.05)significantly in CCl treated groups, urea 4concentration reduced significantly in the CCl 4treated rats, SOD and CAT showed no significant(p<0.05) difference in the treated rats compared withthe control. Glutathione-s-transferase activityreduced (p<0.05) significantly in the CCl treated 4group and increased on treatment with the Liver®gen®. The effect of Liver gen on the PCV and WBCwas dose dependent. No mortality was recorded inthe acute toxicity study at the highest dose of20,000mg/kg. Quantitative analysis of the heavy® metals present in Liver gen showed a higherpercentage of copper compared to cobalt, lead, zinc,iron, nickel, manganese and chromium.Histopathological examinations of the liver sectionsconfirmed the biochemical results and indicated thatCCl induced severe histological lesions in the 4hepatic, renal and brain tissues and this was®ameliorated by Liver gen administration. The®findings suggested that the treatment with Liver genenhanced recovery from CCl induced hepatic 4damage. It could therefore be a good natural foodsupplement capable of reducing oxidative stress andserve as an hepatoprotective agent in particular.Key words: hepatoprotection, aminotransferases,®Liver gen , antioxidant

Effects of herbal remedies (Agyanom mixture, Bolex bitters and Remedia mixture) on hepatic and renal functions in male rats.

No Abstrac

Chemical and physico-chemical properties of orange fleshed sweet potatoes (OFSP) chips dried using solar dyers

In this study, drying technology was employed to process fresh orange fleshed sweet potatoes (OFSP) into dried slices using NSPRI improved solar tent dryer, parabolic shaped solar tent dryer in comparison with open air drying and its effect on the chemical, physico-chemical and mineral constituents of dried OFSP slices was investigated. Results showed that the dried-OFSP contained ash (3.69-4.09 %), fat (4.09-5.09 %), crude fibre (4.69-5.15 %), protein (5.87-8.28 %), carbohydrate (78.22-82.21 %), vitamin C (8.55-20.49 mg/100g), phenolics (0.1-1.28 mg/kg), flavonoids (984-145 mg/kg) and reducing sugar (35.01-82.23 g/100g). The total titratable acidity of the dried OFSP slices varied between 0.56-0.89 %, total soluble solids ranged between 5.70-7.00 °Brix while pH ranged between 4.94-6.47. Zinc, magnesium, potassium, calcium, sodium, iron were present in varying levels but aluminium, lead and cadmium were not detected in all the samples. This study therefore showed that good quality dried OFSP slices with appreciable nutrient content can be obtained from drying in NSPRI solar tent dryers especially with the use of the parabolic shaped solar tent dryer. Thus, the parabolic solar tent dryer is recommended for drying crops. Keywords: Drying technology, Orange fleshed sweet potato, NSPRI solar dyers, Physicochemical propertie

Transmissivity variations in mudstones

Many people in sub-Saharan Africa have to rely on meager water resources within mudstones for their only water supply. Although mudstones have been extensively researched for their low permeability behavior, little research has been undertaken to examine their ability to provide sustainable water supplies. To investigate the factors controlling the occurrence of usable ground water in mudstone environments, an area of Cretaceous mudstones in southeastern Nigeria was studied over a 3 yr period. Transmissivity (T) variations in a range of mudstone environments were studied. The investigations demonstrate that within the top 40 m of mudstones, transmissivity can be sufficient to develop village water supplies (T>1 m2/d). Transmissivity is controlled by two factors: low-grade metamorphism and the presence of other, subordinate, lithologies within the mudstones. Largely unaltered mudstones (early diagenetic zone), comprising mainly smectite clays, are mostly unfractured and have a low T of 1 m2/d in large fracture zones; T 4 m2/d). Dolerite intrusions in unaltered, smectitic mudstones are highly fractured with transmissivity in the range of 1<T<60 m2/d. Thin limestone and sandstone layers can also enhance transmissivity sufficiently to provide community water supplies