Screening and partial purification of amylase from Aspergillus Niger isolated from deteriorated tomato (Lycopersicon Esculentum mill.) fruits

Amylases (EC 3.2.1.1) are cellwall degrading enzymes associated with the pathogenicity of microorganisms in the spoilage of tomato fruits. The use of amylase in many industries has made it very important to optimize production process to achieve maximum yields. Screening and partial purification of Amylase from Aspergillus niger isolated from tomato (Lycopersicon esculentum Mill.) fruits was studied. Amylase producing fungi were isolated from fresh tomatoes kept at ambient temperature (28±1˚C). Isolates were characterized on the basis of their morphological and cultural techniques. Partial purification of amylase was carried out by ammonium sulphate precipitation. The enzyme activity was determined and optimum conditions were obtained. The molecular weights of the crude and partially purified Amylase were determined by SDS PAGE method. A total of five isolates were obtained using basic screening technique for amylase activity, one of the isolates (Isolate code F2) exhibited maximum amylase activity. The fungi isolate code F2 was identified as Aspergillus niger. Optimum conditions for Amylase AMY F2 were ascertained at pH 6.0; temperature 30°C; substrate concentration of 0.3mg/ml, and time of heating of less than 10min. The molecular weights  f the crude and partially purified Amylase AMY F2 were found to be 55kDa and 35kDa respectively by SDS PAGE method. Microorganisms had been an encouraging means of economical production of enzymes in large scale for the food and drug industry. Keywords: Amylase, Partial Purification, Enzyme, Tomato Fruits Rendement et purification partielle de l'amylase de Aspergillus Niger isolé à partir de tomate déterioré (Lycopersicon Esculentum mill.) fruitsLes amylases (EC 3.2.1.1) sont des enzymes dégradant les parois cellulaires associées à la pathogénicité des microorganismes dans la détérioration des fruits à la tomate. L'utilisation de l'amylase dans de nombreuses industries a rendu très important d'optimiser le processus de production pour obtenir des rendements maximaux. Le dépistage et la purification partielle de l'amylase d'Aspergillus niger isolés à partir des fruits à la tomate (Lycopersicon esculentum Mill.) Ont été étudiés. Les champignons producteurs d'amylase ont été isolés à partir de tomates fraîches conservées à température ambiante (28 ± 1 ° C). Les isolats ont été caractérisés en fonction de leurs techniques morphologiques et culturelles. La purification partielle de l'amylase a été réalisée par précipitation au sulfate d'ammonium. L'activité enzymatique a été déterminée et des conditions optimales ont été obtenues. Les poids moléculaires de l'Amylase brut et partiellement purifiée ont été déterminés par un procédé SDS PAGE. Au total, cinq isolats ont été obtenus en utilisant une technique de dépistage basique pour l'activité amylase, l'un des isolats (code isolé F2) présentait une activité amylase maximale. Le code isolant F2 des Fusions a été identifié comme Aspergillus niger. Les conditions optimales pour Amylase AMY F2 ont été déterminées à pH 6,0; température 30 ° C; concentration de substrat de 0,3 mg / ml et temps de chauffage de moins de 10 min. On a trouvé que les poids moléculaires de l'amylase brute et partiellement purifiée étaient respectivement de 55 kDa et 35 kDa par le procédé SDS PAGE. Les microorganismes ont été un moyen encourageant de production économique d'enzymes à grande échelle pour l'industrie alimentaire et pharmaceutique.Mots-clés: Amylase, Purification partielle, Enzyme, Fruits tomate

Distribution of radionuclides and assessment of risk exposure to the miners on a kaolin field

Mining of kaolin deposits are common in Nigeria without considering the background radiation in such environment and the health risks it might pose on the miners. In this study, in-situ measurements of the naturally occurring radionuclides were carried out with the aim of determining the distribution of these radionuclides on the mining field and estimation of the hazard indices exposure risks (γ- and α-radiation risks) to the miners. The study was achieved with the aid of gamma ray detector Super-Spec (RS-125) and global positioning system. The detector used has ability to measure activity concentrations of 238U, 232Th and 40K and gamma doses. For the purpose of this study, only the concentrations of the three radionuclides were considered. For each location, measurements were taken four times, while its mean value was estimated for better accuracy. In all, nineteen locations were occupied in order to cover the study area. Basic kriging method was adopted for the production of spatial distribution of these radionuclides and their corresponding γ- and α-radiation hazard indices. The mean values of 238U, 232Th and 40K are 46.7, 71.8 and 108.7 Bq kg-1 , respectively. When compared to the global standard, it was revealed that 238U and 232Th are greater than the global standard, while 40K fall below the permissible limit. The γ- and α-radiation exposure risks estimated revealed that the mean values of Iγ and Iα are 0.6 and 0.2 respectively. Though the estimated γ- and α-radiation indices showed that the kaolin field is safe for the miners, periodic check is required in order to monitor the rate at which these natural primordial radionuclides (238U and 232Th and their progenies) are being enhanced

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Investigating and combatting the key drivers of viral zoonoses in Africa: an analysis of eight epidemics

Abstract Investigating the interplay of factors that result in a viral zoonotic outbreak is difficult, though it is increasingly important. As anthropogenic influences shift the delicate balance of ecosystems, new zoonoses emerge in humans. Sub-Saharan Africa is a notable hotspot for zoonotic disease due to abundant competent mammalian reservoir hosts. Furthermore, poverty, corruption, and an overreliance on natural resources play considerable roles in depleting biological resources, exacerbating the population's susceptibility. Unsurprisingly, viral zoonoses have emerged in Africa, including HIV/AIDS, Ebola, Avian influenza, Lassa fever, Zika, and Monkeypox. These diseases are among the principal causes of death in endemic areas. Though typically distinct in their manifestations, viral zoonoses are connected by underlying, definitive factors. This review summarises vital findings on viral zoonoses in Africa using nine notable case studies as a benchmark for future studies. We discuss the importance of ecological recuperation and protection as a central strategy to control zoonotic diseases. Emphasis was made on moderating key drivers of zoonotic diseases to forestall future pandemics. This is in conjunction with attempts to redirect efforts from reactive to pre-emptive through a multidisciplinary “one health” approach

A qualitative exploration of malaria operational research situation in Nigeria

<div><p>Background</p><p>Malaria, remains one of the leading causes of high morbidity and mortality in Nigeria despite implementation of several public health interventions for its control. Operational limitations and methodological gaps have been associated with malaria control interventions and research, and these have necessitated the need for a well-tailored Malaria Operational Research (MOR) agenda. However, there is paucity of evidence-based information on relevant stakeholders’ experience, awareness, perceptions and use of MOR and suggestions on setting MOR agenda. As part of a larger study to provide data for national MOR agenda setting, we assessed the MOR research situation from the perspectives of key stakeholders in Nigeria and contribution of MOR to the malaria elimination agenda</p><p>Methods</p><p>We conducted key informant interviews among 40 purposively selected stakeholders from the six geo-political zones in Nigeria. Data was collected using a pre-tested key informant interview guide which comprised issues related to experience, awareness, use of MOR and MOR needs, and suggestions for MOR. We conducted a detailed content analysis.</p><p>Results</p><p>Half of the participants had participated in MOR. Participants perceived MOR as important. Only few were aware of existing framework for MOR in Nigeria while above half expressed that MOR is yet to be used to inform policy in Nigeria. Participants identified several MOR needs such as development of improved diagnostic techniques, and interventions for promoting early diagnosis, prompt treatment and quality programmatic data. Participants opined the need for country-specific prioritised MOR agenda that cut across malaria thematic areas including malaria prevention and case management. Participants suggested the involvement of various stakeholders and multi-disciplinary approach in setting MOR.</p><p>Conclusion</p><p>Although some stakeholders have been involved in MOR, it is still rarely used to inform policy and several needs exist across thematic areas. A broad-based stakeholder involvement, multi-disciplinary approach to agenda setting and its wide dissemination have been suggested.</p></div

Socio-demographic profile, affiliation, designation and research focus of participants [N = 40].

<p>Socio-demographic profile, affiliation, designation and research focus of participants [N = 40].</p

Setting a Nigeria national malaria operational research agenda: the process

Abstract Background Employing malaria operational research (MOR) findings in planning national malaria control programmes is gaining increased attention. The malaria control foci are diverse, resources are limited; therefore, agreeing on priority areas is critical. Hitherto, the process of prioritising MOR questions in Nigeria has been limited to few stakeholders. In support of the National Malaria Elimination Programme’s (NMEP) effort at setting a MOR agenda, the Nigeria Field Epidemiology and Laboratory Training Programme (NFELTP) in collaboration with NMEP conducted preliminary exploratory study to identify key malaria research gaps and needs, and provide data to inform setting a robust national MOR agenda. The process of generating data is presented in this paper. Methods A twelve-member task-team comprising NFELTP, university researchers and NMEP officers was commissioned. Following an inaugural meeting the task-team developed a framework of activities and held five planning meetings, conducted five-week online and self-administered paper-based surveys, key informant interview (KII), two-day desk review workshop, seven-day qualitative data analysis, ten-day result and five-day report writing workshops. Paired group members conducted the interviews across six geopolitical zones of Nigeria. Abridged study report was used for a two-day MOR setting agenda stakeholders’ workshop. Results A structured framework, study protocol and data collection instruments were developed and submitted for ethical approval. The instruments included survey questionnaire for detailed information on researchers and other stakeholders’ experience with MOR, the gaps and needs in thematic MOR areas; KII and Delphi guides. After an initial scoping review, primary data were collected from purposively selected survey participants using mixed methods: - online survey (n = 100), self-administered paper-based survey (n = 85), KII (n = 40), desk review workshop (n = 22) and Delphi interviews (n = 8). Comprehensive lists of research gaps/bottlenecks and needs were generated for each thematic area in malaria control. These were used at a two-day national MOR setting stakeholder workshop (n = 54) to guide the development of national MOR agenda document. Conclusions A systematic approach involving broad stakeholder engagement provided data and evidence-based information for development of a robust national MOR agenda. The processes involved are recommended for use in malaria endemic settings