Nigerian Journal of Biotechnology https://www.ajol.info/index.php/njb <p><em>Nigerian Journal of Biotechnology</em> is a publisher of multidisciplinary peer-reviews original research works and critical reviews on interdisciplinary studies in Biotechnology, Agriculture, Food and Environment interface; and is published twice a year. It serves scientists in the field of Agriculture, Food science and Technology; Animal science, Agriculture Economy and Extension, Fisheries and Aquiculture, Biotechnology, Breeding and Veterinarians.&nbsp;</p> <p>Other websites associated with this journal: <a title="http://biotechsocietynigeria.org/index.php/journals/11-current" href="http://biotechsocietynigeria.org/index.php/journals/11-current" target="_blank" rel="noopener">http://biotechsocietynigeria.org/index.php/journals/11-current</a></p> Nigerian Journal of Biotechnology en-US Nigerian Journal of Biotechnology 0189-1731 <p align="center">Copyright resides with the authors in terms of the Creative Commons License 4.0.</p><p align="center">See <a href="http://creativecommons.org/licenses/by/4.0/">http://creativecommons.org/licenses/by/4.0/</a></p><p align="center">Condition of use: The user may copy, distribute, transmit and adapt the work, but must recognize the authors and the Nigerian Journal of Biotechnology</p> Anti-mitotic and anti-proliferation potentials of aqueous and methanolic extracts of fermented <i>Citrullus vulgaris (ogiri-egusi)</i> seeds https://www.ajol.info/index.php/njb/article/view/199139 <p>There is a growing scientific evidence of the health-enhancing benefits of fermented food and beverages, especially in cancer prevention and&nbsp; treatment. Ogiri-egusi is an indigenously fermented condiment consumed in some West African countries, and prepared mainly from natural fermentation of melon (<em>Citrullus vulgaris</em>) seeds. The condiment has been previously reported to possess anti-oxidative and anti hyperlipid emic properties. In this study, different concentrations of ogiri-egusi extracts were exposed to actively dividing cells from <em>Allium cepa</em> meristematic roots and <em>Saccharomyces cerevisiae</em> for the antimitotic and antiproliferative investigations, respectively. There was a statistically significant reduction in mitotic activities of the treated <em>A. cepa</em> meristematic cells compared to the untreated cells. The mitotic index (MI) of the untreated cells was 28.38 ± 4.58. At a concentration of 1.0 mg/ml, the extracts induced a reduction in the MI to 6.02 ± 2.74 and 4.94 ± 0.61 in the aqueous and methanolic extracts- treated cells, respectively. Some chromosomal aberrations were also observed. In addition, proliferation in yeast cells was significantly inhibited at all the concentrations of the aqueous extract examined as well as at the highest concentration of the methanolic extract. These results provide useful insights to the cytotoxic and genotoxic effects of fermented <em>Citrullus vulgaris.</em></p> <p><strong>Keywords</strong>: Fermented <em>Citrullus vulgaris, Allium cepa</em>, antiproliferation, cytotoxicity, genotoxicity</p> R.A. Ayo-Lawal S.O. Azeez O. Osoniyi Copyright (c) 2020-08-28 2020-08-28 37 1 1 9 10.4314/njb.v37i1.1 Epidemiological Investigation, Serotypes and Distribution of Verocytotoxigenic <i>Escherichia coli</i> (VTEC) in Raw Milk and Milk Products in Uyo, Nigeria https://www.ajol.info/index.php/njb/article/view/199140 <p>Food borne diseases are of great concern globally especially in the developing countries where poor sanitation is applied during collection and processing of milk from animals. The epidemiological investigation, serotypes and distribution of verocytotoxin (VTI and VT2)- producing <em>Escherichia coli</em> in raw milk and milk products were determined using structured questionnaire, Cefixime tellurite-sorbitol MacConkey agar, agglutination kits and VTEC-RPLA Toxin detection Kit. Out of 27 milkers, 7.4 % had primary education, 22.2 % washed the milk utensils with cold water and soap, 11.1 % washed their hands before milking, while 7.4 % milkers washed the udder of the animals before milking. All the yoghurts had the product names; 85.7 % had NAFDAC numbers; 80.0% had Batch Numbers, while 71.4 % had Manufacturer s’ Addresses. The unpasteurized milk samples had <em>E. coli</em> 0157 and non 0157 <em>E. coli</em> counts (CFU.ml<sup>-1</sup>) ranging from 4.0 x 10<sup>2</sup> to 1.7 x 10<sup>3</sup> and 6.0 x 102 to 2.0 x 10<sup>3</sup> , respectively, while <em>E. coli</em> 0157 and non 0157 <em>E. coli</em> counts of milk products were between 1.0 x 10<sup>2</sup> and 1.0 x 10<sup>3</sup> CFU.ml-1. E. coli 0157 had the highest percentage occurrence (38.3%), while <sup>E. coli</sup> 0145 had the lowest percentage occurrence (2.1%). More than 38.3% of the <em>E. coli</em> serotypes produced VT2, while ≥ 12.8% were VT1 producers. The occurrence of VTEC in the unpasteurized milk shows that the milkers should be enlightened on the necessary sanitary practices to adopt during milking and also post-pasteurization contamination of milk products should be avoided.</p> <p><strong>Key Words</strong>: Verotoxigenic, Escherichia coli, Milk, Yoghurt, Nono, Serotypes.</p> O.J. Akinjogunla B.C. Akaka C.U. Inyang Copyright (c) 2020-08-28 2020-08-28 37 1 10 20 10.4314/njb.v37i1.2 Effects of two rhizobacteria inoculants on maize growth performance at different concentrations of glyphosate https://www.ajol.info/index.php/njb/article/view/199142 <p>The use of <em>Rhizobacteria</em> as biofertilizer is on the increase due to the ability of some of the bacteria to solubilize some insoluble essential nutrients in the soil and produce phytohormones necessary for plant growth. The effectiveness of two plant growth promoting rhizobacteria (<em>Bacillus cereus </em>and<em> Pseudomonas aeruginosa</em>) in plant growth promotion at different concentrations of glyphosate were evaluated. Some agronomic parameters such as plant height, size of girth, number of leaves on the screen house and field were measured and recorded. The results of the effects of <em>P. aeruginosa</em> on the height of maize at different concentrations showed that the plants inoculated with the isolates and planted on the soil without glyphosate (control) recorded the highest height on the 2nd (34.9 cm), 4th (52.45 cm), 6th (61.17 cm) and 8th (66.25 cm) weeks after planting, when compared to those planted on the soil spiked with different concentrations of glyphosate. The effects of the isolates on the size of girth of maize on the soil spiked with different concentrations of glyphosate showed the highest girth size on the soil inoculated with <em>P. aeruginosa</em> eight weeks after planting (8 WAP) with a girth size of 2.0cm and least at 14.4 mg/ml of glyphosate with a girth size of 1.2 cm at 8 weeks after planting. Similar trend was observed on the soil inoculated with <em>B. cereus</em> (without glyphosate) with the highest girth in the 2nd and 4th WAP (1.02 and 1.42 cm, respectively). The results of our field studies showed no significant difference (P≤0.05) in the height and number of leaves of the maize at different treatments and time (weeks after planting). Similar trend was observed i n the yield of maize. This study has shown that these isolates can be useful as biofertilizers especially in the absence or at low concentration of glyphosate.</p> <p><strong>Keywords</strong>: Rhizobacteria, maize, Inoculants, Plant-growth-promotion.</p> P.O. Akintokun E. Ezaka A.K. Akintokun O.A. Oyedele Copyright (c) 2020-08-28 2020-08-28 37 1 21 37 10.4314/njb.v37i1.3 Microsatellite markers-based characterisation of elephant grass (<i>Pennisetum purpureum</i>) harvested from selected locations in South-West Nigeria https://www.ajol.info/index.php/njb/article/view/199143 <p>This study was carried out to characterise <em>Pennisetum purpureum</em> harvested from some selected locations in S outh-W estern Nigeria using microsatellite markers. Leaf parts of growing young elephant grass (<em>Pennisetum purpureum</em>) were harvested and immediately preserved in ethanol solution before DNA extraction. Two (2) SSR primers (CTM59 and Xtxp278) were used to assess genetic diversity in <em>Pennisetum purpureum.</em> The result shows that 72% of the molecular variations in the elephant grass exists within the population with 28% among the population; there were no unique characteristics among the Nine (9) populations. Nei genetic index ranged from 0.067 (lowest) observed between Isokan and Odeda populations to 0.158 (highest), between Ifedore and Ikoyi Populations. Morphological characterization showed moderate diversity with two major clusters and one minor cluster.</p> <p><strong>Keyword</strong>: Elephant grass; cultivars; locations; markers</p> O.A. Okukenu A.A. Olajide P.A. Dele M. Wheto B.T. Akinyemi A.O. Jolaosho B.O. Jokosenumi T.J. Shonde Copyright (c) 2020-08-28 2020-08-28 37 1 38 45 10.4314/njb.v37i1.4 Molecular identification of <i>Helicoverpa armigera</i> (Hubner) associated with tomatoes (<i>Solanum lycopersicum L.</i>) in Ogun State https://www.ajol.info/index.php/njb/article/view/199144 <p>The tomato fruit worm Helicoverpa armigera is a key polyphagous agricultural pest with a worldwide distribution. Apart from tomatoes, <em>H. armigera</em> also infests cotton, maize, chickpea and pigeon-pea. Its larvae affect almost all the aerial parts of tomato plants from the vegetative stage to the fruit maturation stage. Due to its high mobility, it causes a huge damage on crops and, as such, early detection of <em>H. armigera</em> from different agro-ecosystems is crucial for implementing control measures. Herein, we used a molecular marker approach to identify <em>Helicoverpa spp</em>. collected from twelve different locations in Ogun State. The <em>H. armigera</em> larvae used for the molecular identification were collected on tomato fruits from the 12 different locations from three agro-ecological zones in Ogun State. Genomic DNA of Helicoverpa was extracted and its purity was checked using Nanodrop spectrophotometer. Cytochrome Oxidase-I (CO-I) region of the DNA was subjected to Polymerase Chain Reaction (PCR) amplification. The PCR amplification of the CO-I gene after gel electrophoresis of PCR products of <em>H. armigera</em> showed a similar banding pattern at 700 base pairs which confirmed the insect as <em>H. armigera</em>.</p> <p><strong>Keywords</strong>: <em>Helicoverpa armigera</em>, Deoxyribonucleic acid, Cytochrome Oxidase-I, Polymerase Chain Reaction, Electrophoresis.</p> B.I. Ewedairo A.A. Osipitan A.R. Popoola L.O. Sanni M.I. Takeet Copyright (c) 2020-08-28 2020-08-28 37 1 46 54 10.4314/njb.v37i1.5 Mutagenic effects of sodium azide on the survival and morphological characters of tomato varieties https://www.ajol.info/index.php/njb/article/view/199145 <p>Sodium Azide (SA)-induced mutagenic variability was studied on four tomato varieties namely Roma vf, Roma savannah, Tropimech and Tima. The SA concentrations used were 0.1%, 0.3%, 0.5% and 0.7%, with 0.0% as control to determine the percentage emergence and growth parameters of the tomato varieties. The plant seeds were pretreated with the various concentrations of the mutagen before planting. The seedlings were raised in the nursery and transplanted after 30 days of planting into the field in polythene bags filled with 70g of a mixture of soil and farm yard manure. The experiment was carried out in randomised complete block design with three replicates. Increase in SA concentration caused a remarkable decrease in the percentage emergence and all other growth parameters evaluated. The effect of the interaction between variety and SA concentration revealed that the interaction was not significantly different from the control at P≤0.05 on the number of leaves, number of branches and leaf length, but the difference was significant for plant height. Formation of two stems was observed at 0.3% Sodium Azide for Roma vf. variety. The 0.1% and 0.3% concentrations of Sodium Azide seem to be promising treatments under the experimental conditions and thus could be used to induce variations for tomato crop improvement. Tima and Roma savannah performed better and were resistant to the mutagen than other varieties, hence they can be recommended as good varieties for further breeding purposes; also Sodium Azide could be a good mutagen for the improvement of tomato plants.</p> <p><strong>Keywords</strong>: Tomato, growth characters, mutagenic, Sodium Azide, morphological variability.</p> C.A. Adeosun K.A. Elem C.D. Eze Copyright (c) 2020-08-28 2020-08-28 37 1 55 62 10.4314/njb.v37i1.6 IL4, IL13, GSTM1 and T1 variants and susceptibility to Schistosomiasis and associated bladder pathologies in Eggua, Nigeria https://www.ajol.info/index.php/njb/article/view/199146 <p>Failure of the human host to elicit adequate immune responses to the adult <em>Schistosoma haematobium</em> worm and continuous strong inflammatory responses to the eggs have been the main causes of bladder pathology in chronic Schistosomiasis. Identification of susceptibility biomarkers for schistosomiasis- associated bladder pathology is necessary in order to detect genetic factors responsible for the infection and spread of the disease. The aim of this study was to identify candidate-biomarkers for susceptibility to schistosomiasis and its associated pathologies. A total of 371 adult participants, comprising 130 males and 241 females from Eggua community, Ogun State, Nigeria, were randomly recruited into a cross sectional study from August 2012 to May 2014. They were screened for <em>S. haematobium</em> ova and bladder pathologies by microscopy and ultrasonography, respectively. Human host susceptibility to schistosomiasis and its associated bladder pathologies were determined by PCR genotyping of Interleukin (IL4 and IL13) genes, and glutathione-S-transferase (GSTT1 and GSTM1) genes. The overall prevalence of S. haematobium in the population was 29.3% (108/369). Bladder pathologies were observed in 32.3% (117/362) of the population. Polymorphisms in IL 4-590 and IL 13-1055 were observed in 24.1% and 9.3% schistosomiasis cases, respectively. The IL 13-1055 polymorphism did not indicate susceptibility to schistosomiasis in males (OR 0.7, 95% CI 0.3-2.1) but a slight risk was found in females (OR 1.1, 95% CI 0.7-1.7). Participants with GSTM1 and GSTT1 polymorphisms expressed elevated risks of bladder pathologies (OR = 4.3, 95% CI 2.0 - 9.2 and OR = 4.2, 95% CI 1.5 – 12.0, respectively), with the pathology and schistosomiasis group having more GST polymorphisms than bladder pathologies.</p> <p><strong>Keywords</strong>: Polymorphisms, Cytokines, GST, schistosomiasis and pathologies</p> O.S. Onile H.O. Awobode A.M. Agunloye C. Marquez-Duenas Cela R.G. Manning C.I. Anumudu Copyright (c) 2020-08-28 2020-08-28 37 1 63 77 10.4314/njb.v37i1.7 Public Toilets in a tertiary institution in the Southern part of Nigeria as Potential Reservoirs of Drug Resistant Pathogens https://www.ajol.info/index.php/njb/article/view/199148 <p>Toilets have long been viewed as a significant potential contributor to human infectious diseases. Various studies worldwide have explored the bacterial communities associated with toilets but only few have focused on their possible role as reservoirs of drug resistant pathogens. To explore this role, four different surfaces from a pay-to-use toilet complex at a tertiary institution in the Southern part of Nigeria were sampled using the swab-rinse technique. Sample processing was done to determine bacterial load, identify bacterial types present in the samples and determine antibiotic susceptibility using standard techniques. Similar levels of bacterial contamination were observed at all the 14 sampling points ranging from 3.6×10<sup>4</sup> to 2.7×10<sup>5</sup> CFU. A higher level of contamination was generally noted on the door handles and floor surfaces. Of the ten different bacterial groups identified,<em> Shigella sp.</em> and <em>Salmonella sp.</em> were the predominant groups (20.6% each). The test isolates showed a wide rate of resistance to antibiotics, with the highest observed against ofloxacin (98.3%) and the least against ceftriaxone (44.4%). Forty-three different antibiogram patterns were detected among the test isolates. Most of the bacteria (63.2%) were associated with MAR index values greater than 0.8. This study shows that public toilets could play a role not just as a reservoir of potential pathogens but more specifically as a potential reservoir of drug resistant pathogenic microorganisms with high MAR indices.</p> <p><strong>Keywords</strong>: Toilet, Reservoir, MAR index, Nigeria</p> K. Otokunefor D.C. Chijioke J.A. Kalio G.O. Abu Copyright (c) 2020-08-28 2020-08-28 37 1 85 93 10.4314/njb.v37i1.8 Responses of African yam bean (<i>Sphenostylis stenocarpa</i> [Hochst. Ex A. Rich]) accessions to viral diseases and serological identification of the associated viruses https://www.ajol.info/index.php/njb/article/view/199149 <p>African yam bean (<em>Sphenostylis stenocarpa</em>) is an orphan crop with lofty nutraceutical benefits grown in Africa. However, pests and diseases often hinder its productivity. Twenty accessions of African yam bean (AYB) were screened for resistance to viral diseases and symptomatic leaves were indexed for the presence of viruses. The Field experiments were conducted during the 2015/2016 cropping seasons (wet and dry seasons). The twenty accessions were grown in triplicates in a randomized complete block design (RCBD) on the field under natural infection and the resistance or susceptibility responses were recorded using visual symptom expression. The characteristic symptoms that were highly prevalent were leaf mosaic and leaf distortion. In both seasons, there were significant (P&lt; 0.05) differences in the severity of these viral symptoms. Also, based on the severity of the symptoms observed in this study, 2 accessions were classified as resistant, 16 as susceptible and 2 accessions as highly susceptible. Two viruses were identified serologically namely Cowpea Mild Mottle Virus (CPMMV) and Blackeye Cowpea Mosaic Virus (BlCMV). The sources of resistance identified in this study would be useful for breeders in developing virus resistant varieties for African yam bean improvement.</p> <p><strong>Keywords:</strong> African yam bean, Virus, Symptoms, ACP-Elisa, Screening.</p> O.M. Ogunsanya C.G. Afolabi M.O. Otusanya M.A. Adebisi Copyright (c) 2020-08-28 2020-08-28 37 1 85 93 10.4314/njb.v37i1.9 Effects Of <I>Calotropis procera</I> Latex on Biochemical and Hematological Parameters in Albino Rats https://www.ajol.info/index.php/njb/article/view/199150 <p><em>Calotropis procera</em> is a wild-growing plant that belongs to the family Asclepiadaceae, commonly found in the tropical regions and is used in the treatment of diseases such as ulcer, inflammation, wound healing, etc. This confers to the increased use of medicinal plants as the major source of traditional medicine worldwide. This study is aimed at evaluating the toxicological effects of <em>Calotropis procera</em> latex on biochemical and hematological parameters in albino rats with a view to understanding the safety of the latex following systemic use. Fifteen (15) albino rats were divided into five groups of three rats each. Group one served as the control, group two received 0.05 ml of the latex solution per kg body weight of the rats , group three received 0.2 ml of the latex solution per kg body weight of the rats , group four received 0.4 ml of the latex solution per kg body weight of the rats , while group five received 0.6 ml of the latex solution per kg body weight of the rats for 14 days. Biochemical evaluations revealed a significant increase in the serum levels of aspartate aminotransferase (83.33 ± 1.76c) and total bilirubin (6.27 ± 4.44b) and a progressive decrease in albumin (3.93 ± 0.04a) with increased concentration of the latex. There was no significant change in the levels of alanine aminotransferase and alkaline phosphatase in all the treated groups. Hematological analyses revealed a significant (p&lt;0.05) decrease in packed cell volume (31.33 ± 1.76a), hemoglobin (10.43 ± 0.59a), red blood cell count (3.90 ± 0.06a) and total white blood cell count (4.10 ± 0.15a) in all the treated groups compared to the control. In conclusion, the results of this study suggest that Calotropis procera latex is relatively toxic as observed in the blood and biochemical parameters related to liver function. Hence, it is recommended that caution should be taken in its use for the treatments of diseases such as wound healing as exposure to the circulatory system can cause vulnerability to its toxic effects.</p> <p><strong>Keywords:</strong> Albino rats, Toxicity, <em>Calotropis procera</em>, latex, biochemical, hematological parameters</p> K. Samuel Y.I. Sudi Copyright (c) 2020-08-28 2020-08-28 37 1 94 100 10.4314/njb.v37i1.10 Applications of molecular markers in Genetic Diversity Studies of maize https://www.ajol.info/index.php/njb/article/view/199151 <p>Molecular markers are efficient for exploiting variations in genotypes as they are not influenced by environmental factors and also speed up breeding programs. They are used to detect large numbers of distinct divergence between genotypes at the DNA level. Genetic diversity study helps to estimate the relationship between inbred lines to make the best hybrid combinations. Lines which are clustered in different heterotic groups are considered as the best hybrid combinations to carry out further breeding activities. Molecular markers are used to meet a number of objectives, including genetic diversity analysis and prediction of hybrid performances in divergent crop species. Agro-morphological and molecular markers have been utilized to study genetic diversity so far. In maize, the uses of molecular markers are important for the evaluation of genetic diversity of inbred lines and in clustering them into heterotic groups. These markers determine genetic similarity of the lines and are used to assess the genetic diversity of maize. Molecular markers have proven valuable for genetic diversity analysis of many crop species and genetically diverse lines are important to improve hybrid breeding.</p> <p><strong>Keyword</strong>: Molecular marker; Genetic diversity; Genetic variation, Diversity Array technology; cluster analysis</p> Degife Asefa Zebire Copyright (c) 2020-08-28 2020-08-28 37 1 101 108 10.4314/njb.v37i1.11 Indole -3- Butyric Acid Induces Plant Regeneration From Stem Cuttings Of Three Medicinal Plants https://www.ajol.info/index.php/njb/article/view/199152 <p>Field regeneration of three (3) medicinal plants - <em>Securidaca longepedunculata</em> (violet tree), <em>Ocimum gratissimum</em> (scent leaf) and <em>Pterocarpus mildebraedii</em> by means of rooting of stem cuttings at different lengths of 10 -15 cm and 15 -20 cm were studied. The effect of the plant hormone Indole-3-Butyric acid (IBA) at 5g/l was tested on rooting, bud sprout and leaf formation of the rooted stem cuttings of the plant species as well as the effect of the length of the stem cuttings on their growth and survival rates. The results of the study revealed that stem cuttings of <em>O. gratissimum</em> treated with IBA and the control treatment sprouted within 5 - 8 days. The treated <em>O. gratissimum</em> stem cuttings produced a slightly higher number of buds (2.58 ± 0.86) when compared to the control (2.00 ± 0.89) with no significant difference at P ≤ 0.05. Stem cuttings of the treated <em>P. mildbraedii</em> cuttings sprouted within 8 -10 days with 1.40 ± 0.37 number of buds, with the control showing no sprouts. Consequently, IBA application produced more leaves (13.00 ± 5.58) and roots (1.33 ± 0.01) than the control. However, <em>O. gratissimum</em> stem cuttings had the highest leaf (13.08 ± 4.47) and root numbers (135.00 ± 13.45) followed by the control with values- 13.00 ± 5.58 for leaf development and 61.66 ± 2.34 for root number respectively. Irrespective of the treatments, none of the stem cuttings of <em>S. longepedunculata</em> sprouted. This study showed that exogenous application of IBA to stem cuttings of the tested plants, except <em>S. Longepedunculata</em>, improved the root number, number of leaves and number of buds.</p> <p><strong>Keywords</strong>: Stem cuttings, Indole-3-Butyric acid (IBA), Rooting</p> C.U. Okafor E.U. Njoku F.C. Ike C.C. Onyekwuluje Copyright (c) 2020-08-28 2020-08-28 37 1 109 121 10.4314/njb.v37i1.12 Enterobacterial Repetitive Intergenic Consensus (ERIC) as a tool for genetic characterisation of bacterial isolates in Nigeria https://www.ajol.info/index.php/njb/article/view/199153 <p>Genetic characterisation as a tool for identification of bacterial isolates in Nigeria has been on the increase in recent years, and the 16s rRNA typing has been a preferred method. Due to cost limitations, there is a need to explore other genetic options. Enterobacterial Repetitive Intergenic Consensus (ERIC) polymerase chain reaction (PCR) analysis is a PCR- only based system which offers the advantage of reduced cost. This study set out to explore the use of ERIC-PCR in genetic characterisation of some selected bacterial isolates from Nigeria and compare it with genetic characterisation using 16s rRNA sequence typing. ERIC-PCR and 16s rRNA typing were carried out on 15 isolates following previously described protocols. Using 16s rRNA typing, thirteen different bacterial species were identified of which majority (85.7%) were Gram negative, with 57.1% belonging to the Enterobacteriaceae family. Using ERIC-PCR, only 13 of the 15 isolates (86.7%) could be typed, resulting in the identification of the 13 different types. ERIC-PCR was able to accurately differentiate between two members of the Proteus species, as well as identify the organisms as similar based on the banding pattern. The results show that ERIC-PCR may play a role as a bacterial identification tool but this role might be more suited to differentiating closely related members of a genus or typing within species rather than general bacterial identification.</p> <p><strong>Keywords:</strong> Genetic characterisation, 16s rRNA, ERIC-PCR, Nigeria</p> K. Otokunefor C.J. Ogugbue B.U. Fajoyomi Copyright (c) 2020-08-28 2020-08-28 37 1 122 128 10.4314/njb.v37i1.13 Potentials of Indigenous <I>Bacillus thuringiensis</I> Isolates from the soil in controlling <I>Fusarium wilt of Cucumber cause by Fusarium oxysporum f.sp cucumerinum</I> https://www.ajol.info/index.php/njb/article/view/199154 <p>Cucumber (<em>Cucumis sativus L.</em>) production is generally low in Nigeria due to continuous soil nutrient limitation and diseases. However, the persistence in the use of agrochemicals for cucumber production in Nigeria is associated with high cost and deleterious effects on man, animal and the environment. This study was conducted to investigate the potentials of indigenous <em>Bacillus thuringiensis</em> (Bt), a spore-forming bacterium known for its insecticidal properties in controlling Fusarium wilt of cucumber. Bacillus thuringiensis strains were isolated from soil samples collected from different farm sites in Abeokuta, Nigeria, and identified phenotypically and molecularly. The in-vitro antagonistic activity of <em>B. thuringiensis</em> strains on <em>F. oxysporum f.sp. cucumerinum</em> was evaluated by dual culture method, followed by pot experiment in the screen house. 16S rRNA gene sequencing was performed on the antagonistic <em>B. thuringiensis</em> to confirm Bt species. The results of the in-vitro antagonistic activity revealed that most indigenous B. thuringiensis strains showed significant growth inhibition of <em>Fusarium oxysporium f. sp. cucumerinum</em>. Similarly, application of <em>B. thuringiensis</em> A and C isolates significantly suppressed the incidence of Fusarium wilt of cucumber in the screen house when compared to the control. The 16S rRNA gene sequencing technique identified the isolates A and C as <em>Bacillus thuringiensis</em> strain LTS-209 and <em>Bacillus thuringiensis</em> strain VITSJ-01, respectively. Hence, indigenous <em>B. thuringiensis</em> A and C isolates should be incorporated into cucumber cultivation for controlling Fusarium wilt disease of cucumber.</p> <p><strong>Keywords</strong>: Cucumber, <em>Bacillus thuringiensis</em>, Fusarium wilt, 16S rRNA gene</p> P.O. Akintokun A.O. Okuwa A.R. Oloyede S.O. Adebajo A.K. Akintokun Copyright (c) 2020-08-28 2020-08-28 37 1 129 137 10.4314/njb.v37i1.14 FAMEs Profile of Oil Produced by Oleaginous Fungi Isolated from Fermented Beverage Wastewaters and Soil https://www.ajol.info/index.php/njb/article/view/199155 <p>Fungal strains isolated from fermented maize (ogi) (PW) and sorghum-based brewery wastewaters (BW) and two soil isolates were evaluated for oleaginicity. The fungal isolates from the wastewater that had lipid content of at least 20% of their biomass were identified by both culture methods and internal transcribed spacer (ITS) 1-5.8S-ITS2 ribosomal DNA sequencing. The isolates were identified to be <em>Aspergillus fumigatus (PW8), Aspergillus flavus (PW10), Candida tropicalis (PW16) and Aspergillus tubingensis (PW3), Trichosporon luoberi (BW7), Aspergillus sp. (BW4) </em>and<em> Candida tropicalis</em> (BW1; BW3). FAMEs composition was determined for the four strains with the highest lipid content by acid-catalyzed transesterification and analyzed by Gas Chromatography-Flame Ionization Detector (GC-FID). Palmitoleic acid was the dominant fatty acid in <em>M. circinelloides </em>and<em> T. reesei</em>, and the best producers of capric and lauric acids were Aspergillus fumigatus and Aspergillus sp. (BW4), respectively. These fatty acids are beneficial in making cosmetics and pharmaceuticals (antimicrobials and dietary supplements). The analysis of the FAMEs profile in the species indicated low amounts or absence of some key long chain fatty acid (LCFA) constituents of biodiesels. Based on the FAMEs profile of <em>M. circinelloides</em> investigated, this strain could hold promise for use as feedstock for biodiesel with genetic engineering and a tailored lipid production favouring enrichment of LCFA.</p> <p><strong>Keywords</strong>: Fungal lipids, wastewater, fatty acid methyl ester, GC-FID</p> I.Y. Nsa G.B. Adeloye A.A. Odunsi B.T. Akinyemi J.T. Tubonemi M.O. Saliu J.P. Adepoju Copyright (c) 2020-08-28 2020-08-28 37 1 138 149 10.4314/njb.v37i1.15 Effects of different media strengths and hormone concentrations on in-vitro regeneration of <i>Vitellaria paradoxa</i> C.F. Gaertn https://www.ajol.info/index.php/njb/article/view/199156 <p>The importance of Vitellaria paradoxa has necessitated its inclusion in the ongoing afforestation project which requires mass production of its seedlings. The shea-butter tree produces oil-rich seeds that are important to cosmetic and food and nutrition industries. It is a deciduous tree which could survive in the dry-savannah and help withstand desert encroachment. However, overexploitation of its timber for firewood and charcoal production made it vulnerable. In-vitro propagation of this species could be a viable means towards its mass propagation. Two plant-hormones: Gibberellic Acid (GA3) and Benzyl Amino Purine (BAP) were used to grow the plant in different combinations making up six treatments (A-F) with 6 replicates in each group. The combinations include 1.5/0, 1.5/1.0, 1.5/1.5, 2.0/0, 2.0/1.0, 2.0/1.5 mg/L of GA3/BAP, which were used to grow 2cm nodal cuttings of the V. paradoxa on half-strength Murashige and Skoog (MS) media. Treatment F (with 2.0/1.5 mg/L GA3/BAP) produced the highest number of leaves (2.4 ± 0.6, 3.2 ± 0.8) and longest shoot length (1.1 ± 0.3 cm, 1.4 ± 0.5 cm) at 4 and 8 Weeks After Inoculation (WAI), respectively. The results of this study showed that application of growth- enhancing hormones for the regeneration of important tree species could provide means for their mass propagation so as to meet the need for afforestation projects.</p> <p><strong>Keywords</strong>: <em>Vitellaria paradoxa</em>, Afforestation, In-vitro propagation, Mass propagation.</p> J.O. Afolabi E.M. Olorode D.B. Olomola Y.O. Fasakin E.A Adekunle Copyright (c) 2020-08-28 2020-08-28 37 1 150 158 10.4314/njb.v37i1.16 Effects Of Different Sterilization Regimes & Growth Regulators On Micropropagation Of Female Date Palm (<i>Phoenix dactylifera</i> L.) https://www.ajol.info/index.php/njb/article/view/199157 <p>The success of in vitro culture techniques is always hampered by microbial contamination. The present study was carried out to develop an efficient protocol for date palm explants sterilization for successful somatic embryos induction and plantlets formation of some date palm varieties. The shoot tips were treated with different sterilizing agents at different concentrations and durations of exposure. The use of ethanol (70%), sodium hypochlorite (3.5% &amp; 70%) and mercuric chloride (0.2%) with or without addition of Tween-20 had different effects on decontamination of the date palm explants. The percentage of explants contaminated with bacteria for sterilants 1, 2 and 4 was 18.8%, 6.3% and 6.3% respectively while 25%, 37.5%, 31.25% and 6.25% were contaminated with fungi for sterilants 1, 2, 3 and 4 respectively. Under the conditions used, a combination of antioxidants (Citric and Ascorbic acids at 100mg/l), 0.2% mercuric chloride and 3.5% sodium hypochlorite solution with 3 drops/100ml of Tween-20 helped in the reduction of chlorosis, contamination and die-back in the shoot tip explants. The explants were further cultured in appropriate media for callus initiation and subsequent somatic embryo induction. Optimal embryogenic callus was obtained from the shoot explant of sterilant number 4 which had the minimal contamination and die-back of all the cultures. After 3 subcultures, the somatic embryos formed were multiplied for shoot development. From this study, we established that the use of appropriate surface sterilant at suitable concentration and duration of exposure of date palm explant to it is indispensable for maximum responses of in vitro cultures.</p> <p><strong>Keywords:</strong> Date palm, Microbial contamination, Sterilizing agents, in vitro, Somatic embryos</p> B.O. Emoghene M. Idu C.R. Eke O. Asemota Copyright (c) 2020-08-28 2020-08-28 37 1 159 168 10.4314/njb.v37i1.17