Cyanide Content of Commercial Gari from Different Areas of Ekiti State, Nigeria

Gari, a creamy-white granular flour made from fresh cassava tubers have been known to contain residual cyanide (hydrocyanic acid) after processing. Cyanide is poisonous and ingestion of Gari beyond the permissible limit can lead to chronic toxicity. This study therefore investigated the presence of this chemical in Gari samples taken from different areas of Ekiti State in Nigeria to ascertain whether or not they are below the permissible level. Random samples of commercial Gari processed locally were collected from 6 areas of Ekiti State in South West Nigeria and screened for residual cyanide content. The alkaline picrate method was used for the screening. Four of the samples contained cyanide in the range of 2.10-9.10 mgHCN/kg which falls below the permissible limit while the remaining two samples had higher residual cyanide of 11.78 and 15.30mgHCN/kg which is above the permissible limit. WHO permissible limit of cyanide concentration is 10.0mgHCN/kg. The samples with concentration above 10mgHCN/kg are from areas where the cassava mash was fermented for less than 12 hours. Keywords: Gari, cyanide, permissible limit, alkaline picrate metho

Pectinolytic and Cellulolytic Enzymes Enhance Fusarium compactum Virulence on Tubercles Infection of Egyptian Broomrape

The use of enzyme could facilitate pathogen penetration into plant host. Here the combination of cellulase and pectinase was ascertained on the pathogenicity of F. compactum (1.4 × 106  propagules ml−1) on broomrape tubercles. F. compactum alone infected all the inoculated tubercles but did not kill any significant number. Infested tomato roots that were inoculated with mycelia plus pectinase (20 U ml−1) had over 50% tubercles dead one week after treatment. Those inoculated with mycelia plus cellulase (20 U ml−1) had above 60% mortality. Mixtures of mycelial plus the two enzymes (10 U ml−1 of each enzyme) showed synergy. The activity catalyzed by an enzyme is a measure of the amount of enzyme present. It was shown that, in a 1 mg (10 U mg−1) cellulase used, 0.055 mg pectinase (1.1 U mg−1) is present. This explains why mycelial plus cellulase mix contends with mycelial plus the two enzymes

Molecular techniques: An overview of methods for the detection of bacteria

Several DNA molecular markers are now available for use in surveillance and investigation of food-borne outbreaks that were previously difficult to detect. The results from several sources of literature indicate substantially different degrees of sensitivities between conventional detection methods and molecular-based methods. The new technology is noted for increased sensitivity over the traditional culture methods which they complement. Key words: molecular techniques, fingerprinting, microorganism. African Journal of Biotechnology Vol. 2 (12), pp. 710-713, December 200

Elucidating mechanisms of endophytes used in plant protection and other bioactivities with multifunctional prospects

Endophytes are abundant in plants and studies are continuously emanating on their ability to protect plants from pathogens that cause diseases especially in the field of agriculture. The advantage that endophytes have over other biocontrol agents is the ability to colonize plant's internal tissues. Despite this attributes, a deep understanding of the mechanism employed by endophytes in protecting the plant from diseases is still required for both effectiveness and commercialization. Also, there are increasing cases of antibiotics resistance among most causative agents of diseases in human beings, which calls for an alternative drug discovery using natural sources. Endophytes present themselves as a storehouse of many bioactive metabolites such as phenolic acids, alkaloids, quinones, steroids, saponins, tannins, and terpenoids which makes them a promising candidate for anticancer, antimalarial, antituberculosis, antiviral, antidiabetic, anti-inflammatory, antiarthritis, and immunosuppressive properties among many others, even though the primary function of bioactive compounds from endophytes is to make the host plants resistant to both abiotic and biotic stresses. Endophytes still present themselves as a peculiar source of possible drugs. This study elucidates the mechanisms employed by endophytes in protecting the plant from diseases and different bioactivities of importance to humans with a focus on endophytic bacteria and fungi

Differences in school connectedness and learned helplessness among undergraduates in a public and private university in Osun State, Nigeria

This study examined differences in school connectedness and learned helplessness among students of a private (Redeemer’s University, Ede) and public university (Obafemi Awolowo University, Ile-Ife) in Osun state, south-west Nigeria. The study utilized an exploratory cross-sectional survey design.278 under-graduate university students were purposively sampled from both universities using a non-probability sampling method. Instruments include, the Learned Helplessness Scale (r = 0.86) and Measurement of School Connectedness (MOSC) questionnaire (r = 0.72).Results show that OAU students had a significantly higher mean score on learned helplessness as opposed to RUN students. OAU students likewise, had significantly lower mean scores on three of the four domains of school connectedness: belonging, communication and connectedness with teachers than RUN students. However, no significant relationship was found between learned helplessness and school connectedness. Further research is recommended to extensively study the variables.Keywords: Learned helplessness, school climate, school connectedness, students, 1Universit

Isolation and characterization of beneficial indigenous endophytic bacteria for plant growth promoting activity in Molelwane Farm, Mafikeng, South Africa

Plant-associated bacteria that live inside plant tissues without causing any damage to plants are defined as endophytic bacteria. The present study was carried out to analyze the phenotypic and genotypic diversity of endophytic bacteria associated with Amaranthus hybridus, Solanum lycopersicum and Cucurbita maxima. A total of 50 bacteria were isolated from the roots of the plants. All the isolates were screened for morphological features (Gram reaction, pigmentation, odour, colour, motility and sharp). Isolates exhibiting difference in morphological features were selected for molecular identification. Eight isolates that exhibited differences in phenotypic aspect were subjected to partial 16S-rDNA gene sequencing using polymerase chain reaction (PCR) for phylogenetic analysis. Sequence analysis using Clustal-X version 1.83 software identified the following isolated bacteria: Stenotrophomonas maltophilia KC010525, Pseudomonas putida KC010526, P. putida KC010527, P. putida KC010528, S. maltophilia KC010529, Achromobacter xylosoxidans KC010530, A. xylosoxidans KC010531 and Achromobacte sp. KC010532. Further evaluation of the bacterial isolates for phosphate solubilization capacity, indole acetic acid (IAA), hydrogen cyanide (HCN) and ammonium gas production, showed all eight bacterial isolates were able to produce IAA (0.32-2.42 mg/mgl-1). However, seven isolates excluding S. maltophilia KC010525 showed ability to produce ammonium. HCN was observed in six isolates: A. xylosoxidans KC010530, A. xylosoxidans KC010531, A. KC010532, P. putida KC010526, P. putida KC010527, and P. putida KC010528. When determining the phosphate solubilizing capacity, it was observed that seven solubilized insoluble phosphate in Pikovskya’s agar plates produced halo zones (1 to 4 mm). Seven tested bacteria were active against Fusarium oxysporum. Therefore, the results indicate that the bacteria isolates may be used as a promising microbial inoculant for plant growth and productivity.Keywords: Plant growth promoting rhizobacteria (PGPR), 16S-rDNA sequencing, HCN production, indole acetic acid (IAA), phosphate solubilization, antifungal activity.African Journal of Biotechnology Vol. 12(26), pp. 4105-411

Microbial Inoculants for Improving Crop Quality and Human Health in Africa

Current agricultural practices depend heavily on chemical inputs (such as fertilizers, pesticides, herbicides, etc.) which, all things being equal cause a deleterious effect on the nutritional value of farm product and health of farm workers and consumers. Excessive and indiscriminate use of these chemicals have resulted in food contamination, weed and disease resistance and negative environmental outcomes which together have a significant impact on human health. Application of these chemical inputs promotes the accumulation of toxic compounds in soils. Chemical compounds are absorbed by most crops from soil. Several synthetic fertilizers contain acid radicals, such as hydrochloride and sulfuric radicals, and hence increase the soil acidity and adversely affect soil and plant health. Highly recalcitrant compounds can also be absorbed by some plants. Continuous consumption of such crops can lead to systematic disorders in humans. Quite a number of pesticides and herbicides have carcinogenicity potential. The increasing awareness of health challenges as a result of consumption of poor quality crops has led to a quest for new and improved technologies of improving both the quantity and quality of crop without jeopardizing human health. A reliable alternative to the use of chemical inputs is microbial inoculants that can act as biofertilizers, bioherbicide, biopesticides, and biocontrol agents. Microorganisms are able to carry out the plant growth promotion, pest and disease and weed control. Microbial inoculants are beneficiary microorganisms applied to either the soil or the plant in order to improve productivity and crop health. Microbial inoculants are natural-based products being widely used to control pests and improve the quality of the soil and crop, and hence human health. Microbial inoculants involve a blend of microorganisms that work with the soil and the soil life to improve soil fertility and health and by extension improve human health. Microbial inoculants have the ability to minimize the negative impact of chemical input and consequently increase the quantity and quality of farm produce. Microbial inoculants are environmental-friendly and deliver plant nutrients to plants in a more sustainable manner. Microbial inoculants can help reduce chemical fertilizer application. Microbial inoculants could include bacteria, fungi and algae. This research summarizes the impact of agricultural chemical inputs on human health. The contribution of microbial inoculants in sustainable maintenance of human health will be expatiated. Advances in microbial inoculants and technology and strategies to explore this natural, user friendly biological resource for sustainable maintenance of plant health will be discussed

Molecular Study of the Phytase Gene in Lactic Acid Bacteria Isolated from Ogi and Kunun-Zaki, African Fermented Cereal Gruel and Beverage

 Background and objective: Phytate is an anti-nutritional agent in cereal foods, making nutritional and health problems in human. The gene responsible for the degradation of phytate has been identified in many bacterial species but not in lactic acid bacteria. The objective of this study was to isolate and characterize phy gene in lactic acid bacteria isolated from Ogi and Kunun-zaki.Materials and methods: Lactic acid bacteria from Ogi and Kunun-zaki were phenotypically screened for phytase production. The phytate-degrading lactic acid bacteria isolates were identified using 16S rRNA gene sequencing. Amplification of phytase (phy) gene was carried out using polymerase chain reaction. Furthermore, phylogenetic analyses were carried out. Soluble proteins of three selected isolates were extracted and analyzed using sodium dodecyl sulphate polyacrylamide agarose gel electrophoresis.Results and conclusion: Totally, 16 isolates of phytate-degrading lactic acid bacteria were identified as Lactobacillus brevis, Lactobacillus plantarum subsp. plantarum, Lactobacillus plantarum, Lactobacillus pentosus and Lactobacillus paraplantarum. The phy gene with an amplicon size of 2.0 kb was amplified and sequenced. Sequence similarities between the phy genes of lactic acid bacteria and that of Bacillus in GenBank included 97-99% with a phylogenetic relationship of less than 40%. The SDS-PAGE electrophoresis analysis revealed a 50-kDa molecular weight of the phytase in the three isolates. This study has shown that phy gene of the lactic acid bacteria presents in fermented foods, suggesting its potential product use as starter to produce fermented foods with improved nutritional qualities.Conflict of interest: The authors declare no conflict of interest

Unravelling the endophytic virome inhabiting maize plant

Endophytes are well-known for their symbiotic interaction with plants and their ability to promote plant growth by producing various metabolites. The most well-studied endophytes are bacteria and fungi. For generations, viruses were misnamed, and their symbiotic associations were ambiguous. Recent advances in omics techniques, particularly next-generation sequencing, have given rise to novel developments in the mutualistic relationships that exist between plants and viruses. Endogenous viruses have received a lot of attention in the animal world, but limited information exists on their functions and importance to plants. Therefore, endophytic viral populations inhabiting the root of a maize plant were assessed in this study for the first time using shotgun metagenomics. Complete DNA was extracted and sequenced using shotgun metagenomics from the maize roots in farming sites where organic fertilization (FZ), inorganic fertilization (CZ), and maize planted with no fertilization (NZ) are being practised in an experimental field. Our results identified 2 orders namely: Caudovirales (67.5%) and Herpesvirales (28.5%) which dominated the FZ site, although they do not show any significant difference (p > 0.05) across the sites. At the class level Microviridae, Phycodnaviridae, Podoviridae, Phycodnaviridae, and Poxviridae dominated the FZ site. Myoviridae and Podoviridae were more abundant in the CZ site, while only Siphoviridae predominated the inorganic fertiliser site (NZ). Diversity analysis revealed that viral populations were more abundant in organic fertilization (FZ). Taken together, this research adds to our understanding of the symbiotic integration of endophytic viruses with maize plants and that their abundance is affected by farming practices. In addition, their potential can be exploited to solve a variety of agronomic issues

Profiling of Bacillus cereus enterotoxigenic genes from retailed foods and detection of the nhe and hbl toxins with immunological assay

Bacillus cereus produces pore-forming toxins responsible for diarrhoea; therefore, rapidly detecting these toxins in food retailed for consumption is needed. The genomic DNA of 100 B. cereus isolates recovered from some retailed foods was extracted and used as a template for enterotoxin detection. The detection of genes of non-haemolyticnonhemolytic enterotoxin (nheA, nheB, nheC), hemolysin BL (hblA, hblC, hblD), entFM, cytK and bceT by the isolates was carried out with PCR  using primers specific for the targeted genes, while the production of Nhe and Hbl enterotoxins in fifty of the randomly chosen isolates was detected with a Duopath Cereus Enterotoxin kit. Ninety-five percent of the isolates carried one or more components of the NHE complex, while 56% had one or more components of HBL. Sixteen out of the 100 isolates carried all the genes for NHE and HBL complex genes. The entFM, cytK and bceT genes were detected in 85%, 74% and 60% of B. cereus isolates, respectively. Starchy foods had the highest incidence of the HBL complex, while nheA and nheC occurred mostly in protein foods with 90% and 87% incidence, respectively. The immunological kit was able to detect the production of  nonhemolytic enterotoxin (Nhe) in all the B. cereus isolates, while 28 B. cereus isolates produced hemolysin (hbl). Nineteen isolates that carried one or more genes encoding  hbl did not produce the toxin. This study clearly showed that retailed foods sold in Ogun State, Nigeria, harbor B. cereus  enterotoxigenic genes responsible for diarrhoea. These toxins can be rapidly detected in foods using both molecular and immunological methods