Aims: This study was carried out to test for the antibacterial effects of Diplaziumsammatii and Pneumatopterisafra plant leaves extracts on some pathogenic bacteria isolates.
Study Design: This study was carried out in triplicates and the results presented are mean values of the recordings.
Place and Duration of Study: This study was carried out in the Microbiology Laboratory of Ekiti State University between January and June, 2011.
Methodology: The plants were collected and air dried at room temperature. The phytochemical constituents were extracted using ethanol, methanol, acetone and cold redistilled water. The agar well diffusion method was used to determine the antimicrobial activity of the plant extracts against Staphylococcusaureus, Salmonellatyphi, Pseudomonasaeruginosa, Klebsiellaspecies, Escherichiacoli and Shigelladysenteriae. Minimum inhibitory concentration (MIC) of the extracts against the test bacteria was also determined.
Results: The acetone extracts gave the highest zones of inhibition (19.0 mm) of the test bacteria at concentrations ranging from 50 mg/ml (9.0 mm) to 250 mg/ml (19.0 mm), while aqueous extracts gave the least zone of inhibition 2.0mm at the same range of concentrations. The MIC was also observed for both plants at 50.0 mg/ml. Phytochemical screening of the plants revealed the presence of tannins, saponins, flavonoids, cardiacglycosides, anthraquinones and alkaloids.
Conclusion: The growth of all bacteria were inhibited at varying degrees thus justifying their use in traditional medicines in treating bacterial infections and other diseases.
Aim: To evaluate the efficacy of using Moringa oleifera seed powder, filtered cold water extract, and autoclaved cold water extract to induce sedimentation of Chlorella variabilis NIES 2541 cells without pH adjustment.
Place and Duration of Study: Department of Plant Science and Biotechnology, University of Nigeria, Nsukka between October, 2017 and July, 2018.
Methodology: Three sets of dry seeds of Moringa oleifera were prepared namely: (a) powdered seed, (b) Cold water extract of the seed which was prepared by soaking powdered seeds in cold water for 30 minutes, and filtering the extract through cheese cloth, and (c) autoclaved extract which was prepared by autoclaving the extract obtained from (b) for 20 minutes at 121°C. Chlorella variabilis was cultivated in BG11 medium and different concentrations of these Moringa seed samples were added to the culture broth, mixed and allowed to sediment. The sedimentation rates were monitored at 30 minutes intervals by taking samples from the top and measuring the optical density at 680 nm.
Results: In all the three cases, the rate of sedimentation increased with increase in the concentration of the Moringa seed used. In comparison with seed powder, use of cold water extract resulted in significant decrease in the sedimentation rate (P<0.05). However, more than 60% sedimentation was achieved by addition of extract from 10 g/l seed powder and incubating for only 30 minutes. Autoclaving the extract did not result in significant decrease in the efficacy of sedimentation (P>0.05). More than 70% sedimentation of Chlorella variabilis culture with an optical density of 3.5 was achieved in 30 minutes by addition of 7 g/l of autoclaved seed extract.
Conclusion: Although using Moringa seed powder resulted in the highest rate of cell sedimentation, autoclaved seed extract can still be used for efficient harvesting of Chlorella variabilis.
Aims: To study vegetation, life-form and chorotype to assess the species diversity between the different community types.
Study Design: Several field trips were carried out to the study area.
Place and Duration of Study: Wadi Wasaa - Jazan - Saudi Arabia.
Methodology: Vegetation diversity, chorology and abundance values were visually estimated and used to form ten clusters of plant community types by statistical methods with Euclidian Distance and Ward method using SPSS program (ver.20). The Shannon-Wiener diversity index was used to estimate diversity, richness and evenness of the recorded species.
Results: A total of 95 species belonging to 75 genera and 31 families were recorded. Poaceae and Euphorbiaceae both are the dominant families constituted 23% of the total species followed by Apocynaceae, Malvaceae. Chamaephytes and therophytes were the prevailed life forms, indicating a typical desert life-form spectrum (chameo-therophytic) type. The chorological analysis revealed a total of 26 species representing 27% fall under monoregional, 56 species (59%) as biregional area and four species were detected under pluriregional region. The highest diversity index (H) was detected in Tamarindus indica community, followed by Acacia asak, whereas the lowest one was calculated in Lawsonia inermis.
Conclusion: Ten plant community types in the wadi were observed. I-Ziziphus spina-christi, II- Salvadora persica III- Anisotestrisulcus, IV- Adenium obesum, V- Ricinus communis. VI-Acacia asak, VII- Lawsonia inermis, VIII- Dobera glabra, IX-Tamarindus indica and X- Leptadenia arborea.
Several amylolytic activities have been isolated from a controlled growing media containing starch and nitrate or ammonium acetate as a carbon and energy source, excreted by the halophilic archaeon Haloferax mediterranei. These enzymes produced in nitrate-containing medium were different from those produced by the organism when cultured in ammonium acetate-containing medium. Haloferax mediterranei was able to grow optimally in both the media but not in a medium with ammonium chloride and starch as exclusive source of nitrogen and carbon, respectively. Growth was significantly lower when nitrate was replaced by ammonium, although there was significant amylolytic activity in the medium. At least six different activities were obtained in the nitrate-containing medium, but only five for the ammonium containing one. These enzymes displayed a different affinity for starch as a chromatographic matrix, when eluted with maltose in a range from 0.02 M to 0.2 M, and differed in their kinetic parameters for starch as a substrate. The average medium length of the products obtained from cracking starch was different for each amylolytic activity, ranging from glucose to larger polysaccharides. Moreover, they exhibited different molecular masses, from 15 to 80 kDa. On the other hand, all of them behaved as typical halophilic enzymes, requiring high salt concentrations from 2M to 4M NaCl for stability and activity. Also, it exhibited an optimal pH ranged from 7 to 8 and showed certain thermophilic behaviour, with maximal activity within 50°C to 60°C. The study of the presence and behaviour of this set of starch degrading enzymes will allow for a better understanding of how halophilic organism obtain the adequate carbohydrates to be incorporated and optimally used.
The research work aims to isolate and identify culturable hydrocarbon utilising bacteria and fungi, from an aged oil impacted soil and these organisms would be used as inoculants in bioremediation of petroleum hydrocarbon pollution. Culturable hydrocarbon utilising bacteria and fungi were harvested from aged oil impacted soil in Ebubu-Ejama Community, Eleme, Rivers State, Nigeria. The hydrocarbon utilising fungi and bacteria were isolated by using mineral salt agar, and petroleum hydrocarbon was supplied to the inoculated plates using the vapour phase technique. Genomic DNA of hydrocarbon utilising bacteria and fungi were extracted and subjected to Polymerase Chain Reaction (PCR). PCR amplified DNA of fungi and bacteria were sequenced by using BIG Dye Terminator Kit on a 3510 ABI sequencer. Internal Transcribed Spacer (ITS) sequence for fungi and 16S rRNA sequence for bacteria were identified using Basic Local Alignment Search Tool (BLAST) algorithm of National Center for Biotechnology Information (NCBI). ITS sequences for fungi shows proximal relatedness to Aspergillus aculeatus strain LrBF25 and Penicillium citrinum strain XQ39. The 16S Sequence for bacteria shows proximal relatedness to Alcaligenes faecalis strain VC-10, Alcaligenes faecalis strain 4339 and Bacillus cereus strain GOAA7MS06. Sequences of the hydrocarbon utilising bacteria and fungi were submitted to GenBank and their Accession numbers were F10: Aspergillus aculeatus MG738329; F11: Penicillium citrinum MG738328; B8: Alcaligenes faecalis MG738324; B9: Bacillus cereus MG738325 and B10: Alcaligenes faecalis MG738326. These organisms could be used to bioaugment the cleanup of petroleum hydrocarbon from the environment.
