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Antibacterial and Hemagglutinating Activity of the Fruit Pulp of Trilepisium madagascariense DC
No full textAim: This study aimed at exploring the hemagglutinating and antibacterial activities of crude lectin from the fruit pulp of Trilepisium madagascariense DC.
Methods: Crude lectin was obtained by maceration of the fruit and ammonium sulphate precipitation. Hemagglutinating activity assay was carried out by determining the ability of the crude extract to agglutinate red blood cells, serial dilution of the crude lectin was done followed by addition of erythrocytes. The crude lectin was subjected to evaluation for inhibition of bacterial growth by the agar well diffusion method against fourteen human pathogenic gram-positive and gram-negative bacteria.
Results: The extract agglutinated trypsinized and glutaraldehyde-fixed rabbit and human erythrocytes with higher specificity for rabbit erythrocytes and better agglutination with trypsinized erythrocytes. Among the various sugar tested, the hemagglutination was best inhibited by galactose. The crude lectin demonstrated mild spectrum antibacterial activity against four pathogenic gram-positive and gram-negative bacteria. The minimum inhibitory concentration ranged from 1.56 mg/ml to 6.25 mg/ml for Streptococcus faecalis, Bacillus anthracis, Staphylococcus aureus and Pseudomonas fluorescens.
Conclusion: The study showed that there is presence of hemagglutinins in the extract and the extract possess antibacterial potential against some pathogenic bacteria tested and can be developed as alternative antibacterial drug that could be employed for the treatment of infectious diseases caused by these pathogens
Diabetes Mellitus: Can Stem Cells be the Answer?
No full textThis review aims to enlighten the readers regarding the past, present and future of stem cells in the treatment of Diabetes. Diabetes is one of the leading causes of morbidity and mortality, affecting more than 415 million people worldwide. It is estimated that one in ten adults will have diabetes by 2030. Diabetes is mainly due to reduction in β-cell mass which are responsible for insulin production. Exogenous administration of insulin is having good impact on restoring glucose homeostasis, but it does not entirely control the minute-to-minute fluctuations in systemic blood glucose. Recently cellular-based therapies have been established for exogenous insulin administration by modern pump technology. One of the most interesting therapies involves substitution of insulin producing islet cells by transplantation. But lack of donor material and lifelong immunosuppression made the technique unfeasible. These restrictions have led to exploration of other sources of β-cells, one of the prospects being the stem cells. Several types of stem cells have been used to make pancreatic β-cells, including human embryonic stem cells / induced pluripotent stem cells, pancreatic stem / progenitor cells, and non-pancreatic stem cells. There is also evidence of adult β-cells regeneration through β-cell replication and cellular reprogramming. Functional restoration of existing β-cells, transplantation of stem cells or stem cell-derived β-like cells might provide new opportunities for treatment. In conclusion it can be said that the research is still wide open to arrive at the efficient reprogramming of various types of stem cells to destine them towards functional β-cells
Isolation and Characterization of Bacteriocinogenic Enterococcal and Lactococcal Strains from South of Morocco Dairy Product
No full textAim: To investigate the occurrence of bacteriocinogenic lactic acid bacteria (BAL) in different animal’s milk of the south of Morocco.
Place and Duration of Study: Laboratory of Microbial biotechnologies and plant Protection, Faculty of Sciences, and Bioprocess and Environment laboratory (LASIME), EST-Agadir, Ibnou Zohr University, Agadir, Morocco, between January 2014 and January 2016.
Methodology: A total of 2000 different colonies, isolated from 42 samples of dromedary, ewe’s, goat and cow spontaneously fermented milk collected from some southern regions of Morocco, were tested for antimicrobial activity. Three indicator strains were used; Listeria innocua, Bacillus subtilis and Enterococcus hirae. The selected strains are phenotypically and biochemically identified, especially by API 20 Strep galleries. In addition, the sanitary and technological aspects of these strains are studied.
Results: Among the active strains 150 strains were selected, and 91% among them were identified as lactic acid bacteria. Out of these, 11 strains isolated from dromedary and ewe’s milk are shown to be active by the agar well diffusion assay (AWDA). Seven (7) strains were identified as Enterococcus faecium, three (3) as Enterococcus faecalis and only one (1) strain was identified as Lactococcus lactis. The twelve strains are active against a wide range of pathogenic and spoilage bacteria, including Listeria monocytogenes, Staphylococcus aureus and Escherichia coli. In addition, all of these strains shown to lack haemolytic, decarboxylatic, proteolytic and lipolytic activities and to be susceptible to most tested antibiotics.
Conclusion: These results suggest a potential application of isolated strains of lactic acid bacteria in bio-preservation of fermented foods especially dairy products
Prevalence of Aflatoxin Biosynthesis Genes According to Aflatoxin Levels in Maize of Different Varieties in Kenya
No full textAims: To determine aflatoxin biosynthetic genes in fungal isolates in relation to aflatoxin levels in maize grain varieties from epidemiologically aflatoxicosis hot spots and non-aflatoxin hot spots agro-ecological zones in Kenya.
Study Design: Purposeful sampling technique was applied targeting regions of variable aflatoxicoses susceptibilities.
Place and Duration of Study: Samples were sourced from Kitui/Kibwezi counties, an aflatoxin hot spot, during 2008-2010 Maize growing seasons. Comparative samples were from Uasin-Gishu county and Perkerra irrigation scheme in Baringo County, both with no previous acute aflatoxicosis and practicing commercial cultivation under rain-fed and irrigation farming systems, respectively.
Methodology: Maize samples (n=295) and fungal isolates (n=61) were analyzed for aflatoxin contamination and presence of aflatoxin biosynthetic genes, respectively. Total aflatoxin quantification was by a commercial Enzyme Linked Immunosorbent Assay (ELISA) kits, Boratest®, while molecular characterization of Aspergillus flavus (n=40) and A. parasiticus (n=21) isolates applied Quadruplex Multiplex PCR technique encompassing four aflatoxin biosynthetic genes: nor-1, ver-1, omt-A and aflR. Findings from the study variables were analyzed according to maize variety, agro-ecological origin of maize samples and fungal species besides type of farming system.
Results: Uasin-Gishu maize samples (n=158) assayed for aflatoxins belonged to six maize commercial varieties; H614, H629, H6213, H6210, H613 and H628 alongside an indigenous variety, Kipkaa. All Perkerra samples (n=61) also belonged to a commercial variety, H513. Contrastingly, all Kitui/Kibwezi samples (n=76) belonged to an indigenous variety, Kikamba (Kinyanya). The varieties H613, H628 and Kipkaa all had the samples (100%) within the Kenyan statutory safe total aflatoxin limit (≤10.0 ppb) whereas Kikamba and H513 varieties had 82.9% and 83.6% samples within safety limits, respectively. Similarly, the mean aflatoxin content for all the seven Uasin-Gishu varieties was only 1.62 ppb while Kikamba and H513 had means of 14.6 ppb and 15.6 ppb, respectively (P=0.05). Positive PCR amplification results were obtained in 96.3%, 84.2% and 80% for Kitui/Kibwezi, Perkerra and Uasin-Gishu isolates, respectively whereas regional distribution of amplicon spectrum was 6, 3 and 2 out of 8, respectively. A similar regional pattern was established regarding prevalence of PCR positive isolates and whose maize samples of origin also tested ELISA-aflatoxin positive, having been 81.5%, 52.6% and 26.7% for Kitui/Kibwezi, Perkerra and Uasin-Gishu. Interestingly, the only isolate PCR positive for all the four genes under assay and whose maize sample of origin had aflatoxins was coincidentally from Kitui/Kibwezi, an epidemiologically aflatoxicosis hot spot agro-ecological zone
Isolation and Biochemical Characterization of Anaerobic Bacteria Strains from Discarded Ruminal Contents of Nigerian Breed Cattle and Preliminary Evaluation of Its Suitability for Animal Feedstuff
No full textAim: The study aimed at isolation and preliminary characterization of anaerobic bacteria from a special crossbreed of Muturu and N’Dama cattle found in parts of Nigeria.
Study Design: The work investigated the suitability of the isolates in in vitro fermentation of biomass and evaluated the relationship between the bacterial flora and their ability to hydrolyse lignocellulosic materials from corn stover and rice straw as an indication of their potential application in animal feedstuff.
Place and Duration of Study: Ahmadu Bello University,Zaria, Nigeria between 2011 and 2013.
Methodology: Authentic isolate confirmation was done using AP120A isolation technique while bacterial enzyme quantification was by real time PCR. The substrate was digested in vitro, and Hungate roll tube technique employed for bacterial culturing.
Results: Isolates confirmation revealed Actinomyces naeslundii, Fusobacterium necrophorum and Clostridium polysaccharolyticum. The mean colony counts were elevated in all the media culture used which further showed significant (P<0.05) difference between rumen fluid medium and medium 10 in Fusobacterium and Clostridium species, indicating a more suitable medium for bacterial culture. Corn stover gave significant biogas volume in the order, corn stover>rice straw> mineral solution. Similarly, the potential ability of the bacteria to produce biogas decreased as follows, Fusobacterium necrophorum >Clostridium parasaccharolyticum>Actinomyces naeslundii. PCR quantification revealed a 5500 bp gene indicating alcohol dehydrogenase.
Conclusion: The rumen of this breed contains useful bacteria species with increased capacity to degrade agricultural waste (biomass) for biogas production and with higher digestibility efficiency that can be employed in feedstuff production. Additionally, Fusobacterium necrophorum produced higher biogas using corn stover as the optimum yielding biomaterial
Molecular Detection, Biological Characterization and Evaluation of Protective Potentiality of a Velogenic Strain of Newcastle Disease Virus Isolate of Bangladesh
No full textAims: The aim of this study was to isolate and characterize Newcastle disease virus (NDV) from recent outbreaks in Bangladesh and protective potentiality evaluation of a velogenic NDV strain.
Methodology: A total of 19 lung tissue samples were collected from dead layer chickens of clinically suspected Newcastle disease (ND) cases. Ten days old embryonated chicken eggs, day-old chick and six-week-old sero-negative chickens were used for the isolation and pathotype determination of the virus. Hemagglutination (HA), hemagglutination inhibition (HI) tests using anti-APMV-1 polyclonal serum were used for primary identification and reverse transcription polymerase chain reaction (RT-PCR) was carried out for the confirmation of the isolated viruses by amplification of F gene of NDV using gene specific primers. Three, out of eleven isolates of NDV were subjected to pathotype determination by mean death time (MDT), intracerebral pathogenecity index (ICPI) and intravenous pathogenecity index (IVPI). One of the isolates of NDV of the year 2012 was selected as vaccine candidate to determine its immunogenicity. ND vaccine was prepared by inactivating virulent Newcastle disease virus (vNDV) with 0.1% formaldehyde and adjuvanted with 40% aluminium hydroxide gel.
Results: Of the 19 samples total eleven isolates were initially identified as NDV by HA and HI tests and finally confirmed by RT-PCR. Results of MDT, ICPI and IVPI indices indicated that all the isolates of NDV of 2011 and 2012 were velogenic in nature. The inactivated vaccine produced satisfactory level of antibody titre at 72 days of post vaccination and revealed 100% protection during challenge experiment with 2 egg lethal dosage, ELD50/bird against both the velogenic strains of NDV.
Conclusion: The frequent outbreaks of ND caused by vNDV in Bangladesh could easily be controlled by using inactivated vaccine prepared with velogenic strain of NDV
Optimization of Lipase Production by Bacillus megaterium
No full textAim: To optimize lipase production by Bacillus megaterium in submerged fermentation.
Study Design: Collection of palm oil press fibres and effluent from different palm oil mills located within Ibadan Municipality. Isolation of Bacillus megaterium by cultivation in medium, submerged fermentation of palm oil press fibres and effluent by B. megaterium to produce lipase. Alteration of the cultural conditions to optimize production.
Place and Duration of Study: All work were done in the Department of Microbiology, Faculty of Science, University of Ibadan, from January–December 2014.
Methodology: Palm oil press fibres and effluent were collected from various palm oil mills and were used as the source of isolation of microorganism. The isolated species were identified by studying the morphological, biochemical, characteristics and 16SrNA gene sequencing. The selected species was screened for lipase production.
Results: The results obtained revealed that maximum lipase production was recorded at pH 7.0 with an activity 2.13±0.15 U/ml while the best temperature that supported the optimum production of lipase was seen at 35°C with an activity of 3.30±0.10 U/ml and the best carbon and nitrogen sources were 2% glucose and 2.5% peptone concentrations showing activities of 1.83±0.05 U/ml and 2.60±0.10 U/ml respectively. An incubation period of 72 hours produced the optimum lipase with an activity of 3.26±0.05 U/ml. The separate additions of 0.3M Ca2+ and 0.3M Cl- supported maximum production of lipase.
Conclusion: This study showed that lipase production by B. megaterium can be optimized and the best conditions for optimization included pH 7.0, temperature of 35°C, 72 hours incubation period in the presence of 2% glucose, 2.5% peptone concentrations and 0.3M Ca2+ and 0.3M Cl-
Inhibitory Effects of 4T1 Breast Tumor Transplantation on Mouse Peripheral Blood Immune Cell Populations
No full textAims: One of serious threats to women\u27s health is mammary cancer whose occurrence, development, and treatment are related to the body’s immunological circumstances. In addition, the cancer also imposes the some effects on the body’s immune system. However, the body’s response is very diverse because it varies from type to type of cancer. This paper reported that the effects of 4T1 cell transplantation on immune cells and spleen in mice.
Methods: Twenty female BALB/C mice were randomly divided into a control group and transplantation group. 4T1 cells were injected into the forth mammary fat pad to construct an animal model of breast cancer metastasis. The lymphocytes from mouse peripheral blood after transplantation and were analyzed by flow cytometry.
Results: The transplantation of 4T1 cells rapidly and continuously decreased the percentages of total T cells, total B cells, cytotoxic T cells and helper T cells in peripheral blood during experimental period (28 days). In addition, memory T cells in the transplantation group were increased at 28 days after transplantation. Only the natural killer (NK) cell percentage was significantly increased at 14 days after transplantation.
Conclusions: 4T1 cell transplantation exerted distinctive effects on the different types of immune cells in mouse peripheral blood: the transplantation of 4T1 cells decreased the levels of total T cells, total B cells, cytotoxic T cells, helper T cells and memory T cells, and the natural killer (NK) cell was increased transiently than in control group
Isolation, Identification and Characterization of Cellulase from a Bacterium Obtained at a Saw-Mill Site in Ile-Ife, Nigeria
No full textCellulose continues to account for one of earth’s most abundant biomass. Cellulase degrades cellulose, thereby making it one of the most sought after enzyme in the commercial market. This research aimed to characterize cellulase with enviable physicochemical parameters from a bacterium isolated from decaying sawdust heap. Isolated bacteria species were screened for cellulolysis. The bacterium with the largest halozone was identified by its 16S rRNA sequence. Optimum growth and cellulase production condition was determined by varying selected factors. Extracted cellulase was partially purified by Ion exchange and gel filtration chromatographic methods. The kinetic parameters were determined. Effect of selected conditions on cellulase activity was studied. Isolate A8 with 58 mm halozone had 96% sequence identity with Bacillus subtilis FJ532063. Optimum activity of 46.18 U/ml at 36 hours was recorded at pH 7, 35 ± 2°C. Yields of 18.5 and 13.5% resulted from ion exchange and gel filtration chromatography respectively. Km was found to be 0.0108 ± 0.0032 mg/ml with a Vmax of 119.3 ± 7.4 µmol/min. Maximum activity for partially purified cellulase was recorded at pH 9.5 and 55°C with stability at 50°C; and pH 9, 35°C with stability at 45°C for crude cellulase. The study showed cellulase from Bacillus subtilis A8 as active and thermostable enough to be further exploited for industrial applications
Relationship between Neutral Invertase Activity and Sugar Contents in Tomato Fruit and Its Functional Prediction Analysis
No full textAims: Neutral invertase (NI) probably plays an important role in sucrose metabolism of tomato, but main function and mechanism are unclear. In this study, contents of soluble sugar and NI activity were measured at different stages in tomatoes of Solanum chmielewskii and Solanum lycopersicumc, meanwhile analyzed the correlation between contents of soluble sugar and NI activity, also cloned NI gene and predicted by bioinformatics for further making clear the function of NI in tomato sugar metabolism.
Study Design: In order to analyze the function and action mechanism of NI, we used the tomato as materials, measured the contents of soluble sugars, activity of NI, and cloned the gene of NI. We also analyzed the NI with bioinformatics, and predicted the molecular function of NI for further making clear the function of NI in tomato sugar metabolism.
Place and Duration of Study: College of Biological Science and Technology, between February 2016 and March 2017.
Methodology: The contents of soluble sugar in tomato fruits were measured with HPLC (High performance liquid chromatography). The function structure and interacting proteins with NI family were predicted by bioinformatics.
Results: The contents of glucose and fructose were significantly higher in Solanum lycopersicum than those in Solanum chmielewskii, and greatly increased along with the process of fruit mature period. Nevertheless, the content of sucrose was raised obviously in the mature period of wild type fruit. In normal cultivated tomato, NI activity was positively correlated with fructose and glucose contents, and negatively correlated with sucrose content. In order to further study the function of neutral invertase, the NI gene was cloned and analyzed by bioinformatics. The analysis results showed that the NI was glycosyl hydrolases with Glyco_hydro_100 conserved domain.
Conclusion: The contents of glucose and fructose were significantly higher in Solanum lycopersicum than those in Solanum chmielewskii, and greatly increased along with the process of fruit mature period. The content of sucrose was raised obviously in the mature period of wild type fruit. NI activity in normal cultivated tomato was positively correlated with fructose and glucose contents, and negatively correlated with sucrose content. The NI was glycosyl hydrolases with Glyco_hydro_100 conserved domain, and might play an important role in the regulation of soluble sugar contents in tomato fruit