Ribulose-1.5-bisphosphate carboxylase-oxygenase and carbon dioxide fixation in the 'rhodospirillaceae'

A single step purification procedure has been developed for the Isolation of ribulose bisphosphate carboxylase/oxygenase from a number of photosynthetic bacteria. The method Involves centrifugation of the soluble protein extracts on step sucrose gradients. Two different molecular forms of ribulose bisphosphate carboxylase/ oxygenase have been purified and characterised from Rhodopseudomonas blastica. The enzymes both have carboxylase and oxygenase activities. One of the enzymes (designated Form I) structurally resembles the plant enzymes, having eight large and eight small subunits, whereas the other (Form II) is composed of six large subunits and lacks small subunits. Peptide mapping of the isolated large subunits shows that the proteins are quite distinct, and are probably coded for by different genes. The two enzymes show marked differences in kinetic properties. The Form I enzyme exhibits optimal activity at pH 8.0, is inhibited by low concentrations of 6-phosphogluconate and has a high affinity for CO2 (Km CO2 - 40 μm), while the Form II has a pH optimum of 7.4, Is relatively Insensitive to Inhibition by 6-phosphogluconate and has a lower affinity for CO2 (Km CC>2 - 102 μm). The in vivo regulation of CO2 fixation and synthesis of the Form I and the Form II enzymes in R. blastica has been studied using batch and continuous culture techniques. Evidence suggests that the synthesis of the Form I enzyme is subject to regulation by a repression/derepression mechanism and this is mediated mainly by the CO2 concentration in the growth medium. The Form II enzyme when svnthesised, is present at low levels and is subject to repression/derepression control by either energy or carbon limitations. The differences in the kinetic and regulatory properties suggest that Rhodopseudomonas blastica synthesises two different molecular forms of ribulose bisphosphate carboxylase/ oxygenase as a means of physiological adaptation to variations in the levels of CO2 in its growth environment

Structural effect of oil price shocks and food importation on economic growth in Nigeria using SVAR model

The study empirically examines the effect of oil price shocks and food importation on economic growth in Nigeria along with two control variables i.e. exchange rate and inflation using Structural Vector Autoregressive (SVAR) Model covering the period of 1970 to 2015. The result from SVAR short-run pattern and long-run pattern indicate that GDP has recently been affected by all variables in the model. More also, it indicates a significant permanent effect of crude oil price shocks and food imports on economic growth, while the result further indicates a transitory effect of exchange rate and inflation on economic growth. For significant t-value of the long run SVAR estimate matrix, confirms long effect of crude oil price shocks, food imports, exchange rate and inflation on economic growth in Nigeria. The results from structural response indicate that crude oil have high positive impact on GDP at the initial period and negative impact at the end of the period. Furthermore, food imports have high negative effect on GDP, while GDP response negatively to exchange rate and inflation rate from the period. The result from the structural decompositions indicates that crude oil price and food imports and exchange rate contribute more variability to GDP, while inflation contribute less variability in explaining the variation of GDP in Nigeria. The study recommends that government should come up with a policy that will focus on alternative sources of government revenue by investing more in real sectors especially agriculture in order to withstand vicissitudes of oil shocks in future.peer-reviewe

Bioethanol potentials of corn cob hydrolysed using cellulases of Aspergillus niger and Penicillium decumbens

Corn cob is a major component of agricultural and domestic waste in many parts of the world. It is composed mainly of cellulose which can be converted to energy in form of bioethanol as an efficient and effective means of waste management. Production of cellulolytic enzymes were induced in the fungi Aspergillus niger and Penicillium decumbens by growing them in mineral salt medium containing alkali pre-treated and untreated corn cobs. The cellulases were characterized and partially purified. Alkali pre-treated corn cobs were hydrolysed with the partially purified cellulases and the product of hydrolysis was fermented using the yeast saccharomyces cerevisae to ethanol. Cellulases of A. niger produced higher endoglucanase and exoglucanase activity (0.1698 IU ml-1 and 0.0461 FPU ml-1) compared to that produced by P. decumbens (0.1111 IU ml-1 and 0.153 FPU ml-1). Alkali pre-treated corn cob hydrolysed by cellulases of A. niger yielded 7.63 mg ml-1 sugar which produced 2.67 % (v/v) ethanol on fermentation. Ethanol yield of the hydrolysates of corn cob by cellulases of P. decumbens was much lower at 0.56 % (v/v). Alkali pre-treated corn cob, hydrolysed with cellulases of A. niger is established as suitable feedstock for bioethanol production

Effect of Solid State Fungal Fermentation on the Chemical Composition of Adansonia digitata Seed

The seed of Adansonia digitata was fermented with the aim of producing additional plant protein food and feed. The seed was subjected to natural fermentation for 120 hours under laboratory condition. Nine moulds and two yeasts were isolated and characterized macroscopically and microscopically as Aspergillus niger, Aspergillus flavus, Penicillium citrinum, Penicillium chrysogenum, Mucor racemosus, Mucor hiemalis, Rhizopus stolonifer, Alternaria tenuis, Scopuloriopsis brevicaulis, Saccharomyces cerevisiae and Schizosaccharomyces pombe. Spores of isolated fungi were used as starter cultures in the fermentation of the seed using solid-state fermentation method for 120 hours. The fermented products were analyzed for proximate and anti-nutrient content using standard methods. The result showed a significant increase (p<0.05) in crude protein, total ash and carbohydrate but decreased significantly (p>0.05) in crude fat and crude fibre. The anti-nutrients in form of total tannins, saponins, oxalate and phytate content were significantly decreased after fermentation.  From the findings in this research, it was concluded that fermented A. digitata seed can serve as additional plant protein food source in food and feed formulation for livestock

Mixed-Culture Fungal Fermentation for Protease and Amylase Production from Adansonia Digitata Seed Through Solid State Technique

Production of amylase from the seed of A. digitata by mixed-culture fungal fermentation was examined. Six fungi were isolated from naturally fermented A. digitata seed in the laboratory and identified as Mucor racemosus, Mucor hiemalis, Penicillium citrinum, Penicillium chrysogenum, Alternaria tenuis and Rhizopus stolonifer. Spores obtained from the fungi were randomly mixed for protease and amylase production using solid-state technique and the enzyme activity was monitor for 120 hours incubation period. The highest protease and amylase activity was obtained at 72 hours (100.8 and 53.60 μmol/mg respectively) by a mixed-culture of P. citrinum, R. stolonifera, A. tenuis and M. racemosus. While the lowest activity (22.2 and 4.0 Umol/mg) was obtained at 120 and 24 hours of fermentation by a mixed-culture of A. tenuis, M. racemosus, M. hiemalis and M. racemosus respectively. The optimum pH for amylase production was pH 5.5 at 28 ± 2 oC. This study revealed that mixed-culture of these fungi especially A. tenuis and M. racemosus were able to produce amylase, hence may be considered as a source for the production of industrial amylase from A. ditata seed

Assessment of indoor and outdoor background radiation levels at school of technology, Kano State Polytechnic, Kano State-Nigeria

A Survey taken by the world health organization (WHO) and the international commission on radiation protection (ICRP) shows that residents of temperate climate spends only about 20% of their time outdoor and about 80% indoors and certain materials use for the construction of such buildings (rocks, soils, tiles etc) are known to be radioactive, and exposure to such radiation results in critical health challenges. Assessment of indoor and outdoor background ionizing radiation level at School of Technology, Kano State Polytechnic, Nigeria was carried out using a digital radiation meter (Radiation Alert Inspector). A total of 49 areas were surveyed and the results obtained showed that the annual indoor reading were highest at Compounding Lab. (2.368±0.35 mSv/yr) and Old Chemistry Lab. (2.169±0.35 mSv/yr), and lowest at New Biology Lab. (1.219±0.21 mSv/yr) and Press Workshop (1.303±0.35 mSv/yr). For the outdoor areas, SOT ring road was found to have the highest value of 0.557±0.17 mSv/yr, while Zoological Garden has the lowest effective value of 0.280±0.05 mSv/yr. For the lecture venues, Auditorium has the highest indoor annual equivalent dose of 2.060±0.49 mSv/yr, while H-Block ND I Textile Class recorded the lowest values of 1.275±0.27 mSv/yr. Base on the aforementioned findings, it was deduced that radiation levels are within the permissible radiation limit as stipulated by the ICRP and UNSCEAR of 2.4 mSv/yr and thus, SOT Kano is radiologically safe.Keywords: Indoor and outdoor, background radiation, equivalent dose, Digital Radiation mete

Assessment of perceived stress amongst primigravidae attending an ante natal clinic in Kano, Nigeria

Pregnancy is an important life event for the woman and is often accompanied by many positive changes and events in anticipation of motherhood; especially for primigravidae. However, the physical, physiological, psychological changes and socio-cultural events related to pregnancy qualify pregnancy as a potent stressor. Stress reactivity during pregnancy may increase the risk of spontaneous abortion, low birth weight and development of mental illness in the offspring. This risk may constitute a big burden in our society considering the high pregnancy and birth rate typical of our society; and such data including for primigravidae is very scanty. This study aims to assess perceived stress amongst primigravidae in our local environment and relate it to socio-demographic and clinical characteristics. We hypothesized, that primigravidae in our local environment will have significant perceived stress. A total of 120 primigravidae were recruited in a cross-sectional study in an antenatal clinic of an urban hospital in Kano city, northern Nigeria. Socio-demographic and clinical information was obtained during an interview and physical examination. Perceived stress was assessed using perceived stress score (PSS-10). Data were analyzed using IBM SPSS statistics version 20.0. The median age of the primigravidae was 20.0 (3) years and 93.3% of them fell within the age range of 16-25 years. Most were secondary school educated house wives living above the poverty line with a singleton pregnancy in the third trimester. The median PSS score of the participants was 13 (8), indicating that the primigravidae had low perceived stress. Majority (53.3%) of the participants had low perceived stress, while the rest had moderate perceived stress and none of them had severe perceived stress. Perceived stress score of the subjects was influenced by the presence or absence of twin pregnancy (Chi = 12.05, P = 0.002). The Perceived stress score was not associated with any of the socio-demographic or clinical characteristics (P > 0.05). It is concluded that the primigravidae generally had low perceived stress which was influenced by the presence or absence of twin pregnancy and not associated with the socio-demographic or clinical characteristics examined.Keywords: Perceived stress, primigravidae, pregnant women, maternal and child health, Kano, Nigeri

Effect of Stem Bark Extracts of Enantia chloranta on Some Clinical isolates

Studies on antimicrobial activity of water, methanol and ethanol extracts of the stem bark of Enantia chlorantha, was carried out by the agar ditch diffusion and tube dilution methods. The clinical isolates used include; Staphylococcus aureus, Streptococcus pyogenes, Shigella sonnei, Proteus mirabilis, Klebsiella pneumoniae, Salmonella typhi, Pseudomonas aeruginosa, Aspergillus niger, and Candida albicans. The isolates were obtained from the Department of Medical microbiology and Parasitology of the University of Ilorin Teaching Hospital. Crude extracts of all solvents used inhibited the growth of all the isolates tested, except Pseudomonas aeruginosa . The Minimum Inhibitory Concentration (MIC) ranged between 25mg/ml to 150mg/ml depending on isolate and extracting solvent. Ethanolic extracts showed greater antimicrobial activity than the other two solvents. The killing rate of the Minimum Bactericidal Concentration (MBC) of the ethanolic extract on S. aureus and P.aeruginosa was 2½hr, and 3hr respectively. Temperature stability study showed that the extracts are stable and active over a temperature range of 30 to121oC.Key words: Enantia chlorantha, antimicrobial property, plant extrac

Continuing Education: Atrial fibrillation: Current trends in management

Quite a number of dramatic interventional advances in the treatment of cardiac arrhythmias such as catheter ablation and implantable cardiac defibrillators for serious ventricular arrhythmias have held the limelight over the last few years. The treatment of atrial fibrillation (AF), which remains the commonest arrhythmia affecting 0.5% of people aged 50-59 years increasing to 12% at age above 74years, has received relatively little attention. There is however, a recent resurgence of interest following some important experimental and therapeutic advances. This article reviews the current understanding of the nature of atrial fibrillation (AF) and some recent developments in the pharmacological and alternative therapeutic approaches. Key Words: Atrial fibrillation, treatment Annals of African Medicine Vol.3(2) 2004: 98-10