Prospecting for electrochemically-active hydrocarbon degrading microorganisms for use in bioelectrochemical remediation of petroleum hydrocarbons

Petroleum hydrocarbons pollution is commonplace in the environment owing to accidental spillages, leakages and indiscriminate disposal. Globally, it is estimated that between 1.7-8.8 million tonnes of oil is released into the aquatic environment annually; and from 1970-2018, 5.8 million tonnes of oil were spilled as a result of tanker incidences. Remediating these spills is a great priority due to their negative impacts on the environment e.g. irreversible habitat loss and threat to the survival of living organisms and public health e.g. genotoxic, mutagenic and/or carcinogenic effects. Work is currently underway to enrich and select electrochemically active hydrocarbon degraders for use in bioelectrochemical remediation of target petroleum hydrocarbons–benzene and phenantherene. Inocula from contaminated matrices (soil, sediment and groundwater) was taken from the Niger Delta region, Nigeria, which was highlighted by a 2011 UNEP report as being highly contaminated with petroleum hydrocarbons. Selected isolates will be identified and inoculated into microbial fuel cell as pure cultures and as microcosms to determine their hydrocarbon removal efficiencies and rates. Bioelectrochemical remediation has promise in speeding up the degradation process while reducing the amount of energy and chemicals used both of which are current impediments to conventional bioremediation processes applied to petroleum hydrocarbons

The use of problem structuring methods to explore the functioning and management of a selected NGO

Includes bibliographical references (leaves 61-64).Poverty eradication is one of the major challenges facing South Africa and the rest of the continent. Concern around poverty alleviation in South Africa encompasses lack of capacity as well as inefficiency in the management and administration of poverty alleviation projects. Therefore, poverty alleviation agencies ought to be mindful of the issues that could affect their organizational efficiency, especially issues around organizational management. Addressing issues of management amongst the poverty alleviation agencies is necessary to assist role players in the implementation of efficient and effective poverty alleviation programs. The research explored issues around the management structure of a selected non-government organisation (SHAWCO). The objective was to develop a shared understanding of the organizational structure, amongst the members of the management team, and identify (if any) inefficiencies within the structure of the organisation. Problem Structuring Methods have been identified as a collection of tools that assist decision makers in addressing complex societal problems, and seek to alleviate or improve situations characterized by uncertainty, conflict and complexity. The study used Problem Structuring Methods to investigate the possible difficulties SHAWCO is facing as a result of management inefficiency. Interviews were used to uncover issues around the functioning and management of the organization, and an interactive problem structuring workshop was later conducted to develop a shared understanding of the identified issues

Potential use of electronic noses, electronic tongues and biosensors, as multisensor systems for spoilage examination in foods

Development and use of reliable and precise detecting systems in the food supply chain must be taken into account to ensure the maximum level of food safety and quality for consumers. Spoilage is a challenging concern in food safety considerations as it is a threat to public health and is seriously considered in food hygiene issues accordingly. Although some procedures and detection methods are already available for the determination ofspoilage in food products, these traditional methods have some limitations and drawbacks as they are time-consuming,labour intensive and relatively expensive. Therefore, there is an urgent need for the development of rapid, reliable, precise and non-expensive systems to be used in the food supply and production chain as monitoring devices to detect metabolic alterations in foodstuff. Attention to instrumental detection systems such as electronic noses, electronic tongues and biosensors coupled with chemometric approaches has greatly increased because they have been demonstrated as a promising alternative for the purpose of detecting and monitoring food spoilage. This paper mainly focuses on the recent developments and the application of such multisensor systems in the food industry. Furthermore, the most traditionally methods for food spoilage detection are introduced in this context as well. The challenges and future trends of the potential use of the systems are also discussed. Based on the published literature, encouraging reports demonstrate that such systems are indeed the most promising candidates for the detection and monitoring of spoilage microorganisms in different foodstuff

Investigation of the diversity and safety of the predominant Bacillus pumilus sensu lato and other Bacillus species involved in the alkaline fermentation of cassava leaves for the production of Ntoba Mbodi

The objective of the study was to investigate the identity, diversity, and safety of the Bacillus population involved in the fermentation of cassava (Manihot esculenta Crantz) leaves for the production of Ntoba Mbodi, a Congolese food. Ninety bacteria were identified by phenotyping and genotyping using ITS-PCR, rep-PCR, and sequencing of the 16S rRNA, gyrA, gyrB and rpoB genes. Moreover, the isolates were screened for the presence of genes coding for haemolytic (HblC, HblD) and non-haemolytic enterotoxins (NheA, NheB and NheC), cytotoxin K (CytK) and emetic toxin (EM1) as well as their ability to produce haemolysin. The investigations revealed the predominance (72.21 %) of species of the Bacillus pumilus group i.e. B. safensis (48), B. pumilus (7), and B. pumilus sensu lato (10). Other species of Bacillus including B. cereus sensu lato (11), B. megaterium (4), B. subtilis (4), B. amyloliquefaciens (2), B. siamensis (2), B. licheniformis (1) and Lysinibacillus louembei were also identified. Haemolytic, non-haemolytic and cytokin toxin genes were detected in the B. cereus strains which were also able to produce haemolysin. The emetic toxin gene was not detected in any isolates. The toxin genes screened were not detected in any of the non B. cereus species

The Effects of Quorum Sensing Inhibitors on Multispecies Biofilms of the Oral Cavity

Biofilms are defined as assemblages of one or more species of surface-associated bacterial cells and other microorganisms encapsulated by a self-produced extracellular matrix consisting primarily of polysaccharides, extracellular DNA, and proteins that adhere to firm surfaces. Biofilm formation is important in the microbial world and is considered an advantage over independent, planktonic counterparts due to its ability to resist antibiotics and evade the host’s immune responses. Biofilms can form on a variety of environmental surfaces and can be considered both helpful and problematic depending upon the context of the biofilm. Pathogenetic biofilms within the oral cavity are particularly harmful because they provide little to no health benefits, but rather more commonly cause problems and disease such as dental caries, periodontal diseases, and persistent intra-radicular infections within treated root canals. Many of the damaging and disease-causing biofilms of the oral cavity often cause pain due to dental decay leading to dental caries and periodontal diseases. The WHO calls dental caries the most common and wide spread non-communicable disease in the world. Dental caries and other oral biofilm-related diseases can colonize any person with teeth across the entire world regardless of race, gender, age or socioeconomic status. In addition to causing oral diseases, if left untreated, studies suggests that oral biofilms can lead to more serious systemic diseases such as cardiovascular disease, bacterial pneumonia, diabetes mellitus, rheumatoid arthritis, and low birth weight. Quorum sensing (QS) is a communication system in biofilms that regulates gene expression in accordance to cell population density. QS in bacteria requires a minimum, critical concentration of bacterial cells in close proximity to one another in order to induce common, coordinated gene expression and coordinated responses to changes in their environment. QS gives bacteria the protection from antibiotics and immune responses that a biofilm provides. Quorum sensing inhibitory molecules, often referred to as quorum quenchers (QQ), have been studied due to their ability to disrupt the QS system in biofilms which potentially provides an alternative method of treatment for biofilm related diseases. With the era of antibiotic resistance at an all-time high, the need for alternative methods of treatment are crucial for researchers to investigate. The aim of this project is to investigate how multi-species oral biofilms respond to known QQ

Influence of soy fortification on microbial diversity during cassava fermentation and subsequent physicochemical characteristics of garri

This study investigated the influence of the addition of soy products on the microbiology, nutritional and physico-chemical characteristics of garri, a fermented cassava product. Malted soy flour (MSF) and soy protein (SP) were separately added (12% w/w) to cassava mash prior to controlled fermentation, while non-supplemented cassava mash served as a control. Identification of lactic acid bacteria (LAB) and aerobic mesophilic bacteria was accomplished by repetitive sequence based (rep)-PCR analysis and 16S rRNA gene sequencing. Physicochemical, nutritional and sensory characterisation of control and soy-fortified garri was performed using conventional methods. rep-PCR allowed differentiation of 142 isolates into 41 groups corresponding to 6 species of LAB and 25 species of aerobic mesophiles. LAB isolates belonged to the genera Lactobacillus, Weissella, Leuconostoc and Lactococcus with Leuconostoc mesenteroides being the dominant species in control and MSF-cassava while Weissella cibaria dominated SP-cassava fermentation. Aerobic mesophiles included Gram positive and negative bacteria such species of the genera Bacillus, Clostridium, Staphylococcus, Serratia, Acinetobacter and Raoultella. Diversity of aerobic mesophiles varied between control, MSF- and SP- cassava mash. Protein content of soy-fortified garri increased from 0.73% to 10.17% and 10.05% in MSF and SP garri respectively with a significant decrease in total cyanide from 26 to 11 ppm. Results from physicochemical and organoleptic evaluation indicate that supplementation of cassava with soy products prior to fermentation can produce acceptable garri. Soy products can be considered a viable option for protein fortification of garri, a low protein food with the aim of combating malnutrition

Fatty acid metabolism of Mycobacterium tuberculosis: a double-edged sword

Mycobacterium tuberculosis can cocatabolize a range of carbon sources. Fatty acids are among the carbons available inside the host’s macrophages. Here, we investigated the metabolic changes of the fatty acid-induced dormancy-like state of M. tuberculosis and its involvement in the acquisition of drug tolerance. We conducted metabolomics profiling using a phosphoenolpyruvate carboxykinase (PEPCK)-deficient M. tuberculosis strain in an acetate-induced dormancy-like state, highlighting an overaccumulation of methylcitrate cycle (MCC) intermediates that correlates with enhanced drug tolerance against isoniazid and bedaquiline. Further metabolomics analyses of two M. tuberculosis mutants, an ICL knockdown (KD) strain and PrpD knockout (KO) strain, each lacking an MCC enzyme—isocitrate lyase (ICL) and 2-methylcitrate dehydratase (PrpD), respectively—were conducted after treatment with antibiotics. The ICL KD strain, which lacks the last enzyme of the MCC, showed an overaccumulation of MCC intermediates and a high level of drug tolerance. The PrpD KO strain, however, failed to accumulate MCC intermediates as it lacks the second step of the MCC and showed only a minor level of drug tolerance compared to the ICL KD mutant and its parental strain (CDC1551). Notably, addition of authentic 2-methylisocitrate, an MCC intermediate, improved the M. tuberculosis drug tolerance against antibiotics even in glycerol medium. Furthermore, wild-type M. tuberculosis displayed levels of drug tolerance when cultured in acetate medium significantly greater than those in glycerol medium. Taken together, the fatty acid-induced dormancy-like state remodels the central carbon metabolism of M. tuberculosis that is functionally relevant to acquisition of M. tuberculosis drug tolerance

Peste des Petits Ruminants: Aetiology, Pathology, Immunology, Disease Status in Africa, Diagnosis, Control, Prevention and Treatment: A Review

Peste des petits ruminants (PPR) is a disease of economic and veterinary importance leading to considerable economic losses. PPR affects small domestic and wild ruminants. Sheep and goats are the natural hosts of PPR but cattle, pigs, African buffaloes and camels are also affected by the PPR virus. Clinical signs seen are mainly fever, mucopurulent nasal and ocular discharges, cough, dyspnoea, gastroenteritis leading to severe diarrhoea. The post mortem lesions seen are congested lungs, congestion of gastrointestinal tract, especially the discontinuous streaks of congestion, which is referred to as Zebra stripes or Zebra markings, oedematous and congested retropharyngeal and mesenteric lymph nodes, linear haemorrhages in the intestinal mucosa and splenomegaly. PPR infection is characterized by a rise in packed cell volume (PCV), increase in haemoglobin concentration (HbC), leukopenia with lymphopenia. The serum alkaline phosphatase, alanine aminotransferase and aspartate aminotransferase activities are elevated, blood urea nitrogen and creatinine concentrations are also elevated. The disease is also characterized by disseminated intravascular coagulopathy (DIC) evidenced by prolonged prothrombin time (PT), prolonged activated thromboplastin time (APTT), thrombocytopenia, and hypofibrinogenemia. In PPR infection, serum biomarkers of oxidative stress such as vitamins A, C, E and glutathione activity decreases while serum catalase, superoxide dismutase, glutathione reductase and xanthine oxidase increase. Diagnostic techniques include histopathology, virus isolation, immunocapture enzyme-linked immunosorbent assay (icELISA), Competitive Enzyme Linked Imunnosorbent Assay (cELISA) and Combined Indirect ELISA (CI-ELISA) agar gel immunodiffusion, real-time polymerase chain reaction (RT-PCR), reverse transcription-loop mediated isothermal amplification assay (RT-LAMP), Luciferase immunoprecipitation system (LIPS) and immunohistochemistry. Therefore, this review focused on the aetiology, epidemiology, pathology, immunology, and disease status in Africa, diagnosis, control, prevention, treatment and control of this disease

Bioelectrochemical remediation of petroleum hydrocarbons

Aims There is interest in cleaning up hydrocarbon contaminated sites via bioremediation as the process is environmentally friendly and sustainable. However, some of the bioremediation methods are very slow and expensive, often limited by the availability of electron acceptors and nutrients. Furthermore, electron flow is difficult to control. These major hurdles could be overcome with bioelectrochemical systems. The aim of this project is to develop and test bioelectrochemical systems-based petroleum hydrocarbon remediation technologies at laboratory scale in environmentally-relevant conditions with a view for field deployment. Methods and results* Bioelectrochemical systems for the treatment of target petroleum hydrocarbons in a more effective, efficient and sustainable manner will be developed and evaluated for their performance. The hypothesis is that electrodes inserted in soil/sediments/groundwater could increase oxidant delivery to support anaerobic biodegradation of petroleum hydrocarbons in the respective matrices, thereby, speeding up bioremediation and minimising and/or eliminating the need for energy and chemicals. Conclusions* Findings from the study would be useful in remediating sites contaminated with petroleum hydrocarbons e.g. the ones in Ogoniland, Niger Delta region of Nigeria. Significance of study* This study will contribute to the development of an environmentally sustainable, efficient and low-cost solution that requires no or minimal chemical additives for the remediation of petroleum hydrocarbons pollutants that are a threat to human health and the environment. The processes developed are expected to be better than natural attenuation as well as typical bioremediation processes like landfarming. References United Nations Environment Programme UNEP, (2011) Environmental Assessment of Ogoniland [Online] Available at: http://postconflict.unep.ch/publications/OEA/UNEP_OEA.pdf Accessed on 5/2/2020 Wang X, Aulenta F, Puig S, Esteve-Nunez A, He Y, Mu Y, Rabaey K. 2020. Microbial electrochemistry for bioremediation. Environmental Science and Ecotechnology. 1: 100013

Survival of inoculated Salmonella on the shell of hens' eggs and its potential significance

The aim of this research was to evaluate the risk of inoculated Salmonella persisting on the outside of the shell of hens' eggs. Hens' eggs were surface inoculated with a cocktail of Salmonella strains and stored for up to 54 days at 4, 10 and 20 °C and at 80 and 90% relative humidity. Salmonella survival showed an irregular pattern, with extremes of high recovery and no recovery. However, salmonellae were always recovered after resuscitation. Monte Carlo simulation of different scenarios using relevant assumptions indicated that the distribution of surviving Salmonella was skewed towards low numbers, suggesting higher chances of Salmonella persisting on the eggs in low numbers (<104 cfu egg−1). Although numbers were low, the research demonstrated the ability of salmonellae to survive on the shells of eggs following contamination and this clearly has safety implications for handling of eggs in the food industry and the domestic environment