Studies of action of heavy metals on caffeine degradation by immobilised Leifsonia sp. strain SIU

Caffeine is an important naturally occurring compound that can be degraded by bacteria. Excessive caffeine consumption is known to have some adverse problems. Previously, Leifsonia sp. strain SIU capable of degrading caffeine was isolated from agricultural soil. The bacterium was tested for its ability to degrade caffeine as the sole carbon and nitrogen source. The isolate was encapsulated in gellan gum and its ability to degrade caffeine in the presence of heavy metals was determined. Out of the nine heavy metals tested, Copper (Cu), Mercury (Hg), and Silver (Ag) had significant effects on caffeine degradation at 1mg/L. Therefore, the concentration of these heavy metals was varied from 0 - 1 mg/L to see at what concentration each metal it has effect. Ag and Hg showed effect at 0.1 mg/L with caffeine degradation of 64.05 and 52.17% respectively, while Cu showed effect at 0.8 mg/L with caffeine degradation of 64.74%. These bacterium features make it an ultimate means for caffeine bioremediation. This is the first report of effect of heavy metals on caffeine degradation by immobilised Leifsonia sp. strain SIU.Keywords: Caffeine, Degradation, Heavy metals, Immobilisation, Leifsonia sp

Modelling Growth Kinetics of Klebsiella sp. FIRD 2 on TBT-Resistant Containing Lead

Tributyltin (TBT) is one of the most toxic substances ever deliberately introduced into the marine environment. The high toxicity of TBT has resulted in a wide range of adverse effects on biological systems ranging from bacteria to mammals and from the molecular to the community level. One of the most deleterious effects of TBT is imposex. The growth kinetics of TBT-Resistant Bacterium containing lead was studied. In this study various lead concentrations ranging from 1 to 100 mg/dm3 were used. Seven kinetic models (Teissier, Monod, Yano, Luong, Aiba, Webb, and Haldane,) were investigated and the accuracy of the fitted models were evaluated using statistical analysis such as coefficient of determination, adjusted coefficient of determination (R2) and root mean square (RMSE). Aiba model was fitted to the experimental growth kinetics data and gave a very good fit with an R2 of 0.98 and RMSE of 0.0042 respectively. The calculated value for the Aiba constants such as maximal growth rate, half saturation constant and half inhibition constant rate symbolized by μmax, ks, and ki, were 0.038 hr-1, 0.38s mg/dm3 and 34.38 mg/dm3respectively. This is the first report of growth kinetics of TBT-Resistant bacterium by Klebsiella sp. FIRD 2 Containing lead.Keywords: Growth Kinetic models, Klebsiella sp. FIRD 2, lead, TBT-resistant bacteria

Prediction of cumulative death cases in Brazil due to Covid-19 using mathematical models

The novel corona virus (2019-nCoV) infection has spread rapidly to other provinces and neighbouring countries since the emergence of the first cases at Wuhan, China. Estimation of the death cases by mathematical modelling can help to determine the potential and severity of the outbreak and to provide critical information on the type and intensity of disease response. In this paper, we present different growth models such as Von Bertalanffy, Baranyi-Roberts, Morgan-Mercer-Flodin (MMF), modified Richards, modified Gompertz, modified Logistics and Huang in fitting and analyzing the epidemic trend of COVID-19 in the form of total number of death cases of SARS-CoV-2 in Brazil as of 15th of July 2020. The MMF model was found to be the best model with the highest adjusted R2 value with the lowest RMSE value. The Accuracy and Bias Factors values were close to unity (1.0). The parameters obtained from the MMF model include maximum growth of death rate (log) of 0.03 (95% CI from 0.02 to 0.028), curve constant (δ) that affects the inflection point of 0.7057 (95% CI from 0.68 to 0.73) and maximal total number of death (ymax) of 17,619,760 (95% CI from 9,705,100 to 34,994,517). The MMF model predicted that the total number of death cases for Brazil on the coming 15th of August and 15th of September 2020 will be 132,787 (95% CI of 123,422 to 142,863) and 212,166 (95% CI of 192,578 to 233,746), respectively. The predictive ability of the model utilized in this study is a powerful tool for epidemiologist to monitor and assess the severity of COVID-19 in Brazil in months to come. However, as with any other model, these values need to be taken with caution due to the unpredictability of the COVID-19 situation locally and globally

Tributyltin-resistant bacteria from contaminated surface sediment

Resistance to tributyltin (TBT) was examined in pure bacteria cultures isolated from TBT-polluted sediments. We defined a TBT-resistant bacterium as one which grows in a TBT concentration above the reported concentration at the sampling site (Kong Kong Laut), which was less than 1000μg/l. More than 15 pure colonies of bacteria were isolated which are mostly Gram negative and more than 80% percent of these isolates are possible TBT-degrading bacteria due to their ability to resist TBT concentration of up to 1000μg/l. All TBT-resistant bacteria are potential TBT degrading bacteria but may not degrade the TBT. However, TBT degrading bacteria must be TBT resistant bacteria. These TBT-resistant bacteria were also examined for their biodegradability and they shows capability of degrading TBT, suggesting that these microorganism can utilize the carbon source in the pollutant. This study has successfully shown that these bacteria isolated from Kong Kong Laut are potential TBT-degrading bacteria and this also paves a major pathway for sustainable remediation solution

Prevalence of gastrointestinal helminthes in dromedary camels (Camelus dromedarius) slaughtered at Kano, Nigeria

A preliminary study was carried out in August 2004 to determine the prevalence of gastrointestinal helminthes in camels slaughtered at Kano metropolitan abattoir. A total of 177 fecal samples made up of 98 from males and 79 from females were collected and analyzed for the presence of helminth eggs and worm burden by sodium chloride floatation method and McMaster technique for egg counts. An overall prevalence rate of 78.5% was recorded. Eight types of helminthes were diagnosed, with Oesophagostomum radiatum, Haemonchus contortus, and Strongylus species being the most common. Of the 177 camels sampled, 61.0% (108) had single infection, while 17.5% (31) had multiple infections. A prevalence rate of 75.5% in males and 43.0% in females, and 24.5% in males and 8.9% in females was recorded for single and multiple infections respectively. There was no significant difference between infection rate in males and females. Interview on management system revealed that most infections emanated from poor management practices, which included lack of routine anthelminthic therapy. Therefore, improvement in herd health management through general hygiene, routine deworming and provision of proper nutrition will help in alleviating the severe effects of helminthoses on camel health and productivity. Keywords: Gastrointestinal helminthes; dromedary camels; slaughterhouse; NigeriaAnimal Production Research Advances Vol. 2 (3) 2006: pp. 164-16