Heavy Metal Contaminants in Popularly-consumed Vegetables of Freetown, Sierra Leone

The contamination of the environment with heavy metals is one of the challenges that make up Sierra Leone's environmental problem, with urbanization being one of the main causes; due to the lack of proper waste dumpsites and landfills for infrastructural development, rivers, and streams are polluted. The loss of biodiversity, but river and stream pollution have a significant impact on aquatic life. Animals and plants in contaminated water sources "may perish or reproduce improperly". This study assessed the level of concentration of heavy metals namely; chromium (Cr), iron (Fe), copper (Cu), zinc (Zn), and lead (Pb) in some commonly-consumed vegetables like Manihot esculenta (Cassava) leaves, Ipomoea batatas (Potato) leaves, Amaranthus viridis (African spinach), Corchorus olitorius (Krain krain); Solanum lycopersicum (Tomatoes); Cucumis sativus (Cucumber); Brassica oleracea (Cabbage); Abelmoschus esculentus fruits (Okra); Capsicum annuum (Bell Pepper); and Lactuca sativa (Lettuce) which were all purchased at local market places in Freetown. The vegetable samples were analyzed using an X-ray fluorescence machine (XRF) to determine their heavy metal concentration. The goal was to determine the food safety status of the vegetables by comparing the results to the maximum permissible limit (MPL) for vegetables, as set by WHO/FAO. The levels of Zn, Cr, Fe, Cu, and Pb in all vegetable samples varied from 4.70 – 5.69 %; 3.46 – 4.58 %; 4.00 – 4.52 %; 2.87 – 3.42 %; and 0.5 – 1.2 %, respectively. This result indicates that the metals were present at unsafe levels. According to the result, the maximum concentration values are much higher than the MPL value suggested by WHO/FAO for vegetables, implying that eating vegetables from the source market sites in this study may pose a health risk to humans. Heavy metals in vegetables should be monitored on a regular basis to prevent excessive accumulation of these heavy metals in the human food chain. When it comes to vegetable marketing, certain precautions should be implemented.

Normative references of fetal chest circumference in a Nigerian population

A linear relationship between gestational age and fetal thoracic size has been observed, with growth occurring at a regular rate from 16 to 40 weeks.Objective: To determine the fetal chest circumference in normal late second and third-trimester pregnancies in a Nigerian population.Materials and Methods: This was a descriptive cross-sectional study carried out on gravid women with normal singleton pregnancies at 22 ­ 38 weeks gestational age. We recruited 440 eligible gravid women. The fetal gestational age was estimated from the last menstrual period and an early first trimester ultrasound report (< 10 weeks). The fetal chest circumference was measured on an axial view of the fetal chest after ensuring adequate visualisation of the four cardiac chambers, both fetal lungs and ribs. The other fetal biometric parameters were determined using the previously established guidelines. Descriptive statistics, Pearson's correlation, and regression analysis were used as appropriate. Statistical tests were considered significant at P ≤ 0.05.Results: The mean age of the subjects was 29.8 ± 4.6 years (range = 18-45 years). The chest circumference of the fetuses ranged from 16.56 ± 0.29 cm to 30.87 ± 6.88 cm. The fetal chest circumferences increased with advancing gestational age (16.56 ± 0.29 cm at 22 weeks to 30.87 ± 6.88 cm at 37 weeks gestational age). There was strong positive correlation between chest circumference and menstrual gestational age (r=0.85, p=<0.0001), biparietal diameter (r=0.88, p<0.0001), abdominal circumference (r=0.90, p<0.0001) and fetal length (r=0.88, p<0.0001).Conclusion: The fetal chest circumference grew as the pregnancy progressed. There was a positive linear correlation between fetal chest circumference and menstrual gestational age as well as the other fetal biometric parameters.

Early detection of Pre-XDR TB with line probe assay in a high TB burden country

Background - Worldwide, tuberculosis (TB) is one of the top 10 causes of death. Drug resistant tuberculosis has lately become a major public health problem that threatens progress made in Tuberculosis (TB) care and control worldwide. The aim of this study was to determine the prevalence of Pre-extensive drug resistant TB among MDR TB in North Central of Nigeria. Methods - This study was conducted from October, 2018 to August, 2019 with 150 samples. In Nigeria, guidelines for DR-TB as recommended by WHO is followed. All the samples from the patients who gave their consent were transported to a zonal reference TB laboratory (ZRL). Results - Mean age was 38.6 ± 13.4 years with peak age at 35-44. Out of these 103 samples processed with LPA, 101(98%) were rifampicin resistant and 2 were rifampicin sensitive, 99(96%) were INH resistant and 4 (4%) were INH sensitive, 5(5%) were fluoroquinolone resistant, 98(95%) were fluoroquinolone sensitive, 12 (12%) were Aminoglycoside + Capreomycin resistant, 91(83%) were Aminoglycoside + Capreomycin sensitive. Conclusion - Multidrug resistant TB and its severe forms (Pre-extensive & extensively drug resistant TB) can be detected early with rapid tool- Line Probe Assay rapid and prevented timely by early initiation on treatment.

Pyramidal cell morphology and cell death in the hippocampus of adult mice with experimentally induced hydrocephalus

Background: Hippocampus is a neural structure in the temporal lobe that plays a crucial role in learning and memory. Cognitive impairment with learning disabilities is a common feature in hydrocephalus and is more prominent in adult-onset hydrocephalus. The aim of this study is to describe the morphological alterations in the pyramidal cells of the hippocampus of adult hydrocephalic mice. Method: Hydrocephalus was induced in adult albino mice by intra-cisternal injection of kaolin suspension (250 mg/ml in sterile water). They were sacrificed 7, 14 and 21 days post-induction. Morphological analysis was carried out on hematoxylin and eosin stained coronal sections of the hippocampus: the pyramidal neurons (normal and pyknotic) in the CA1 and CA3 subregions were counted and the pyknotic index (PI) was calculated. The somatic and dendritic features of Golgi stained pyramidal neurons were examined by light microscopy in both hydrocephalic and control mice. Result: The PI was significantly greater in the CA1 region of the hippocampus in the hydrocephalic groups compared to the age matched controls. The dendritic processes of pyramidal neurons in the CA1 region were fewer with shorter terminal branches in the hydrocephalic mice than in controls; this was pronounced at 7 days post-induction. In the CA3 region, there was no difference in dendritic arborization between hydrocephalic and control mice. Conclusion: Acute adult-onset hydrocephalus was associated with increased pyknosis and reduced dendritic arborization in hippocampal pyramidal cells in the CA1 but not CA3 region

Seroprevalence and determinants of hepatitis B viral status in pregnant women attending antenatal clinics in an urban community of Oyo state, South-West Nigeria

Background: The burden of hepatitis B virus (HBV) is assuming an epidemic proportion globally, causing grave hepatic and other complications. Mother-to-child transmission is one of the main ways of acquiring the disease. It is thus incumbent on researchers to delve more into the epidemiology of HBV. The objectives of this study is to assess respondents’ knowledge on HBV, estimated the burden of the disease among pregnant women attending antennal clinics in Ogbomoso, Nigeria and identified significant determinants of HBV positive status of the participants.Methods: This facility-based cross-sectional study was conducted among 168 pregnant women recruited using systematic random technique. Pretested interviewer-administered, semi-structured questionnaire was used for data collection. Both descriptive and inferential statistics were carried out.Results: Mean age of the respondents was 34±10 years, 90.5% of the respondents were 20-40 years old. HBV awareness level among the respondents was 51.8% and more than half (59.5%) of them possessed poor knowledge of the virus. Twelve percent (12.0%) of the respondents were seropositive for hepatitis B surface antigen (HBsAg). Significant determinants of HBsAg positivity were; Level of education (AOR=0.11, CI=1.56-3.47), Socio-economic class (AOR=3.23, CI=1.48-3.02) and family type (AOR=4.51, CI=0.19-0.35).Conclusions: The burden of HBV was high among pregnant women in the study population. Awareness and knowledge of the respondent was low. Authors recommend aggressive awareness campaigns on the disease. Improving the socio-economic conditions of women will go a long way in reducing the scourge of this dreadful disease in Nigeria.

Evaluation of Cissus populnea gum as a directly compressible matrix system for tramadol hydrochloride extended-release tablet

The aim of this study was to evaluate and compare the compactibility, mechanical and release properties of tramadoltablets prepared by direct compression using cissus gum, a naturally occurring plant polymer as directly compressibleexcipient in comparison with xanthan gum. Compactibility was measured by Heckle, mechanical properties by tensilestrength and friability, and release properties by dissolution profile. Student t-test with GraphPad Prism 5 was used toidentify differences between data at p < 0.05. The result showed that the Py of xanthan formulation was significantlylower than cissus formulations (p = 0.03). Onset of plastic deformation was directly dependent on the concentrationof the polymer and the properties of the active ingredient. The presence of the active ingredient retarded the onsetof plastic deformation. There was increase in crushing strength and tensile strength with decrease in friability as theconcentration of the polymer increased in all formulations. The mechanical properties of cissus gum and xanthan gumformulations were not significantly different (p > 0.05). Tramadol dissolution decreased as the concentration of thepolymers increased. Cissus gum has some properties that would make it suitable as direct compressible excipient inmatrix systems for extended-release.

Acute stroke in Jos University Teaching Hospital: cranial computed tomographic findings and accuracy of the clinical diagnosis

Background: Cranial computed tomography (CT) is an invaluable tool useful in promptly differentiating hemorrhagic from ischemicstroke. However, due to the cost of CT, there has been a reliance on the World Health Organization (WHO) clinical diagnosis of stroke in some low­resource settings. Objective: The aim of the present study is to determine the pattern of acute stroke as seen on CTand to determine the accuracy of the clinical diagnosis using the WHO method. Materials and Methods: This was a cross­sectional descriptive study conducted from September 2014 to June 2015. We included 150 consecutive patients aged 18 years and above with acute stroke. Initial physician diagnosis using the WHO method was obtained, followed by a radiological evaluation using CT. The Statistical Package for the Social Sciences version 20.0 with results represented in simple proportions and percentages. Statistical level of significance was set at P ≤ 0.05. Results: The mean age (standard deviation) was 57.97 (14.2) years with females making up 50.7% (76/150). Ischemic stroke was found to be the more common type of acute stroke (69.3%) (104/150) with the parietal lobe being the site most commonly affected by both strokes types. The positive predictive and negative predictive values of the WHO clinical diagnosis for ischemic and hemorrhagic strokes were 79.13% and 68.97% and 68.97% and 79.13%, respectively. Conclusions: A low accuracy in the WHO clinical diagnosis of stroke was observed. Ischemic stroke is the more common stroke and parietal lobe the most commonly affected site

Clients and service providers' assessment of Public and Non-Governmental Youth-Friendly Health Services in Lagos Nigeria: a mixed method approach

Background: The World Health Organization prescribed that Youth-Friendly health services must be accessible, acceptable, equitable, efficient, effective, comprehensive and appropriate to meet the health needs of young people. Objective: To compare the clients' and service providers' assessment of services offered at the public and Non-Governmental Organization (NGO) Youth Friendly facilities (YFF) in Lagos Nigeria. Methods: A mixed method approach was used. Structured questionnaires were administered on youths (294 from public and 273 from NGO YFF) from ten (5 public and 5 NGO) YFF. Ten key informant interviews with service providers were also conducted between March 1st and December 31st 2014. SPSS version 22 was used to analyze quantitative data while thematic analysis of interviews with service providers was done. Results: Youths who utilized the public YFF had 60% chance (AOR 1.6, 95%CI 1.3 ­ 2.5, p= 0.005) of experiencing longer waiting times, 80% chance (AOR 1.8, 95%CI 1.2 ­ 2.8, p=0.004) of being counseled in a separate room and over two-fold chance (AOR 2.3, 95%CI 1.7 ­ 3.3, p <0.001) of having free services. Sexual and reproductive health was the major complaint area of the youths while funding was the major challenge of service providers at both the public and NGO YFF. Conclusion: To address the needs of the youths, there is a need to provide more funds and provide necessary logistics required by YFF

The Predominant Lactic Acid Microorganisms and Proximate Composition of Spontaneously Fermented Gari and Fufu, Cassava Food Products

Aim: The present study is focused on determining if there are differences in the types of organisms responsible for spontaneous fermentation in two types of cassava food products, namely, fufu and gari, while also ensuring that the expected organoleptic properties associated with the fermentation process from this study location is reproducible. Study Design: A Complete Randomized Design (CRD) with three replications was adopted and used to test for significant differences between the two cassava products. Place and Duration of Study: The roots of two cassava varieties namely, TMS 97/0211 (white pulp) and TMS 97/2205 (yellow pulp) were obtained from the International Institute for Tropical Agriculture (IITA), Ibadan, and were processed at Ede, Nigeria between March and May 2016. Methodology: Using standardized spontaneous fermentation methods, the two varieties of cassava, were sampled eight hourly over a period of 5 days, for lactic acid bacteria and fungi. Samples were incubated anaerobically, representative microbial populations were enumerated and identified using standard microbiological protocols. Proximate analysis and sensory evaluations were conducted. Results: The results showed that the predominant lactic acid bacterial organisms were Lactobacillus brevisand L plantarum. On the other hand, the representative lactic acid fungal isolates were identified as Neurospora crassa, Aspergillus fumigatus and Saccharomyces spp. Investigation of succession organisms revealed differences between the dry cassava finished product, gari and the wet finished product, fufu. The fungal organisms were the predominant starter organisms found in gari, while, the predominant starter organisms found in fufu were the bacterial types. Conclusion: The present results show that in spite of the spontaneity of the fermentation process, the yellow cassava variety supports the growth and reproduction of similar fermentation organisms as the white variety. Furthermore, the prevailing microenvironment in the fermentation set up, that is, wet or dry is the most important factor in determining the predominating organisms in the fermentation process and the organoleptic and nutritional characteristics of the final product. Results from this study show that it is possible to reproduce the organoleptic and nutritional characteristics peculiar to this test location using the isolated lactic acid microorganisms.

Electroencephalography abnormalities in generalized epilepsy and their predictors: A multicenter experience

Background: In spite of the overwhelming significance of knowledge of basic elements of electroencephalography (EEG) in its application to the diagnostic workup and the management of patients with suspected or already established generalized epilepsy (GE), there is a dearth of data on the pattern and utility of clinical variables that can independently determine EEG abnormalities in GE. Objective: The study was designed to evaluate the frequency and pattern of EEG abnormality as well as assess the utility of clinical variables in predicting the likelihood of an abnormal EEG in GE. Methods: It was a cross-sectional study involving the analysis of EEGs of consecutive patients with clinical diagnosis of idiopathic GE from three centers over a 7-year period. Information on sociodemographic and seizure variables was obtained. The International Federation of Societies for Electroencephalography and Clinical Neurophysiology definition of interictal epileptiform discharges (interictal epileptiform activity [IEA]) was adopted in the study. Results: A total of 403 patients comprising 242 (60%) males and 161 (40%) females with clinical diagnosis of GE had EEG. Their age ranged between 2 weeks and 70 years, with a median age of 21 years and an interquartile age of 26 years. Two hundred and thirty-seven (58.8%) and 213 (52.9%) patients had abnormal EEG and IEA, respectively. Before adjustment for confounders, female gender (P = 0.0001), pediatric age group (P = 0.0388), duration of epilepsy of 1­4 years (P = 0.01387), uncontrolled seizure (P = 0.0060), and seizure frequency (P = 0.0001) were significantly associated with the presence of abnormal EEG. However, age, female gender, poor seizure control, and seizure frequencies were the independent predictors of EEG abnormality. Conclusion: The study showed that about 58% of patients with GE patients had abnormal EEG. Age, poor seizure control, and high frequency of seizure were independent predictors of the presence of EEG abnormality

The Compaction, Mechanical and Disintegration Properties of Modified Pennisetum glaucum (Poaceae) Starch in Directly Compressed Chloroquine Tablet Formulations.

Pennisetum glaucum L (Millet) starch is a potential source of direct-compression excipient for use in tableting but has not been commercially explored. The aim of this study was to investigate the compaction properties of pregelatinized freeze (PFDMS) and oven-dried (PODMS) millet starch in directly compressed Chloroquine tablet formulation and compare with the native starch (NMS) and Avicel®. Tablets were directly compressed using the starch in drug-diluent ratios of 1:2, 1:4 and 1:9 and evaluated by compaction, mechanical and disintegration properties. The result showed that PFDMS and PODMS starch samples had higher flow properties in comparison to the native starch and PFDMS also gave the fastest onset of plastic deformation. Tablets formulated with PFDMS and PODMS showed acceptable mechanical and disintegration properties comparable with Avicel® in the order Avicel® > PFDMS > PODMS > NMS. The pregelatinized starch samples can be substituted for Avicel® for direct compression.

Prevalence of Hepatitis B Virus Infection in Nigeria; 2000-2013: A Systematic Review and Meta-Analysis

Vaccination against the hepatitis B virus (HBV) in the West African nation of Nigeria is lower than many Sub-Saharan African countries. In Nigeria; HBV is reported to be the most common cause of liver disease. However; the extent of HBV exposure among Nigerians at average risk is unknown. Our aim; therefore; was to accurately estimate the HBV prevalence for the country and the prevalence for specific subgroups. We used electronic databases to select systematic reviews and meta-analyses from 2000 to 2013. Forty-six studies were included (n = 34;376 persons). We used a random effects meta-analysis of cross-sectional and longitudinal studies to generate our estimates. The pooled prevalence of HBV in Nigeria was 13.6 (95 confidence interval [CI]: 11.5; 15.7). The pooled prevalence ( [95 CI]) among subgroups was: 14.0 (11.7; 16.3) for blood donors; 14.1 (9.6; 18.6) for pregnant women attending antenatal clinics; 11.5 (6.0; 17.0) for children; 14.0 (11.6; 16.5) among adults; and 16.0 (11.1; 20.9) for studies evaluating adults and children. HBV prevalence in Nigeria varied by screening method [ (95 CI)]: 12.3 (10.1; 14.4) by using enzyme-linked immunosorbent assay; 17.5 (12.4; 22.7) by immunochromatography; and 13.6 (11.5; 15.7) by HBV DNA polymerase chain reaction. HBV infection is hyperendemic in Nigeria and may be the highest in Sub-Sahara Africa. Our results suggest that large numbers of pregnant women and children were exposed to HBV from 2000 to 2013. Increased efforts to prevent new HBV infections are urgently needed in Nigeria

Prevalence of Anemia among Pregnant Women and its Determinants in Northern Nigeria.

Objectives: We conducted a baseline survey in Northern Nigeria to determine the coverage, adherence, prevalence, barriers and facilitating factors affecting utilization of prenatal iron and folate supplementation (IFAS) from service delivery and recipient perspectives. Methods: The survey employed both quantitative and qualitative methods. Anemia (hemoglobin concentration Hb<110 g/L. g/L, Hemocues®) was measured among 1664 pregnant women 15-45 years. Results: The prevalence of anemia was high across all states surveyed (Jigawa 71.1%, Katsina 61.4%, Yobe 88.8%, Zamfara 62.2%). Although 70% of women from all states received some IFAS in their last pregnancy, <50% reported consuming IFAS ≥90 days. Utilization of IFAS among pregnant women was affected by such factors as misconception about IFAS, influences of male spouse and older women. Religion and cost were not found to constitute barriers to IFA utilization. Knowledge of health workers on how to track IFAS utilization was generally low. Most health facilities surveyed reported no IFA stock-out in the three-month preceding the survey. Over 55% of interviewed women knew the benefits of ANC in pregnancy from all the state and >60% knew the benefits of IFAS in pregnancy. Conclusions: This study has confirmed that anaemia is a problem among pregnant women in Nigeria. Despite awareness about ANC and IFAS and relatively high coverage of distribution of IFAS, utilization is relatively low. Neither the awareness of IFAS nor ANC attendance translates to IFA utilization. There is a need to address some misconceptions about IFAS resulting from cultures, beliefs and influence of male spouses and older women through Behaviour Change Communication (BCC) interventions.

In vitro Antimicrobial and Antioxidant Analysis of Gallic Acid from the Leaves of Ludwigia abyssinica A. Rich.

Aims: To evaluate the antimicrobial and antioxidant potentials of a biologically active compound isolated from the leaves of Ludwigia abyssinica A. Rich. Study Design: Antimicrobial and antioxidant analysis of compound from the n-butanol fraction of plant leaf. Place and Duration of Study: Chemistry and Microbiology Laboratories, Faculty of Science, Obafemi Awolowo University, Ile-Ife between November 2011 and September 2012. Methodology: Chromatographic and nuclear magnetic resonance techniques were used to isolate and characterize the biologically active compound, respectively. Disc diffusion, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) measurements were used for antimicrobial test. 1, 1-diphenyl-2-picrylhydrazyl hydrate (DPPH) radical scavenging assay was used for antioxidant test. Results: The phenolic compound, 3,4,5-trihydroxybenzoic acid, also known as gallic acid was isolated from the n-butanol fraction of L. abyssinica leaf. It showed broad spectrum antimicrobial activities with zones of inhibition in the range 26.67±1.53 to 32.00±1.00 mm for the test bacteria and 6.67±1.15 to 30.33±0.58 mm for the test fungal strains. MIC and MBC values for gallic acid ranged from 12.5 to 200 μg ml-1 and 50 to 400 μg ml-1, respectively, comparing favourably with the standard reference drug used. DPPH radical scavenging activity for the compound was IC50 = 9.38 μg ml-1 compared with IC50 = 27.08μg ml-1 obtained for the standard ascorbic acid. Conclusion: The results show that gallic acid from Ludwigia abyssinica leaves possesses In vitro antimicrobial and antioxidant properties and thus the plant has potentials as a source of natural health-giving products, given further investigations

Launaea taraxacifolia Ameliorates Cisplatin-Induced Hepato-renal Injury.

Aims: The protective potential of aqueous leaf extract of Launaea taraxacifolia against Cisplatin-induced hepato-renal damage in Wistar rats. Study Design: Randomized controlled experiment Place and Duration of Study: Experimental Animal Unit and Department of Anatomy, University of Ibadan between July and September, 2013. Methodology: Thirty rats were randomly divided into 6 groups of 5 rats each. Group Acontrol; Group B- cisplatin (CIS) alone; Group C and D- Launea taraxacifolia (LT) 100 mg and 400 mg respectively and Group E and F- treated with LT 100 mg and 400 mg respectively and then given CIS. Kidney and liver sections were taken for histopathological evaluations. Serum samples were taken for alanine aminotransferase [ALT], aspartate aminotransferase [AST], bilirubin [BIL], total protein (TP), albumin [ALB], blood urea nitrogen (BUN) and creatinine (CREAT) level assessments. The remaining tissues were processed for the assessment of biochemical markers of oxidative stress: Lipid peroxidation (LPO), Superoxide dismutase (SOD), Catalase (CAT) and Glutathione (GSH). Results: Hepatorenal histological toxicities were observed in rats exclusively exposed to cisplatin while dose-dependent ameliorations of these histopathologies were seen in those with combined exposure (Groups E and F) with the aqueous extract of Launaea taraxacifolia and virtually normal histoarchitecture was seen in extract alone treated rats. The hepatic (ALT, AST, BIL) and renal (BUN and CREAT) injury markers significantly (p<0.05) increased in groups exclusively exposed to cisplatin with less severity in cotreated (E and F) groups. The oxidative stress markers, LPO, SOD and CAT levels which were significantly elevated (p<0.05) in cisplatin exclusively exposed Group B, were not altered in other groups when compared with control. However, glutathione level significantly decrease (p<0.05) in GSH levels in kidney and liver tissues of (Group B) cisplatin alone relative to control. Conclusion: Launaea taraxacifolia provides protection against cisplatin-induced hepatorenal damage through its antioxidant activities.

Clinical errors and medical negligence

This paper discusses the definition, nature and origins of clinical errors including their prevention. The relationship between clinical errors and medical negligence is examined as are the characteristics of litigants and events that are the source of litigation. The pattern of malpractice claims in different specialties and settings is examined. Among hospitalized patients worldwide, 3-16% suffer injury as a result of medical intervention, the most common being the adverse effects of drugs. The frequency of adverse drug effects appears superficially to be higher in intensive care units and emergency departments but once rates have been corrected for volume of patients, comorbidity of conditions and number of drugs prescribed, the difference is not significant. It is concluded that probably no more than 1 in 7 adverse events in medicine result in a malpractice claim and the factors that predict that a patient will resort to litigation include a prior poor relationship with the clinician and the feeling that the patient is not being kept informed. Methods for preventing clinical errors are still in their infancy. The most promising include new technologies such as electronic prescribing systems, diagnostic and clinical decision-making aids and error-resistant systems

Studies on the Catalytic Properties of Partially Purified Alkaline Proteases from Some Selected Microorganisms

Aims: The research was done to study the conditions enhancing catalytic activities of alkaline proteases from Vibro sp., Lactobacillus brevis, Zymomonas sp., Athrobacter sp., Corynebacterium sp. and Bacillus subtilis. Methodology and Results: The proteolytic enzymes were purified in 2-step procedures involving ammonium sulphate precipitation and sephadex G-150 gel permeation chromatography. The upper and lower limits for the specific activities of proteases from the selected microorganisms were estimated at 20.63 and 47.51 units/mg protein with Zymomonas protease having the highest specific activity towards casein as its substrate and purification fold of 3.46, while that of Lactobacillus brevis protease was 8.06. The native molecular weights of these active proteins ranged from 30.4 to 45.7 kDa with Athrobacter sp. protease having the highest weight for its subunits. The proteolytic enzymes had optimum pH range of 8 to 10 and temperature range of 50 to 62 ºC accounting for the percentage relative activity range of 75 to 94% and 71 to 84 % respectively. The activities of Lactobacillus brevis and Bacillus subtilis proteases were maximum at pH 9 and 10 respectively. Lactobacillus brevis protease activity was maximum at temperature of 62 ºC, while beyond this value, a general thermal instability of these active proteins was observed. At above 70 ºC, the catalytic activities of Corynebacterium sp., Vibrio sp., Zymomonas sp. and Arthrobacter sp. proteases were progressively reduced over a period of 120 min of incubation, while Bacillus subtlis and Lactobacillus brevis proteases were relatively stable. Effect of metal ions was investigated on the catalytic activity of protease from the microorganisms. Lactobacillus brevis, Zymomonas sp., Arthrobacter sp., Corynebacterium sp. and Bacillus subtilis protease activities were strongly activated by metal ions such as Ca+2 and Mg+2. Enzyme activities were inhibited strongly by Cu2+ and Hg2+ but were not inhibited by ethylene diamine tetra acetic acid (EDTA), while a slight inhibition was observed with K+, Na+ and Fe2+. Conclusion, significance and impact of study: The outcome of this present study indicated useful physico-chemical properties of proteolytic enzymes that could be of biotechnological use in enhancing enzyme catalytic efficiency.

Partial purification and characterization of a thermostable alkaline protease from Lactobacillus brevis

Aims: The research was done to study the partial purification and characterization of thermostable alkaline protease from Lactobacillus brevis. Methodology and Results: The enzyme was purified in a two-step procedure involving ammonium sulphate precipitation and Sephadex G-150 gel permeation chromatography. The protease was purified 8.04 fold with a yield of approximately 30% after purification with Sephadex G-150 column. It has a relative molecular weight of 33.2 kDa and optimally active at a temperature of 60 oC and pH 9.0. The maximum velocity Vmax and Michaelis constant Km of the protease produced during the hydrolysis of casein were 66.66 U/mg protein and 3.33 mg/ml. It was strongly activated by Ca2+ and ethylene diamine tetra acetic acid (EDTA), mildly inhibited by Na+, K+, Mg2+ and Fe2+ and strongly inhibited by Cu2+ and Hg2+. The ability of the enzyme to improve the cleansing power of various detergents was also studied. Conclusion, significance and impact of study: The findings in this study suggest that the protease is a suitable candidate for detergent formulation and biotechnological applications.