Browsing by Author "Boga, Hamadi I."
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Item 16S-rRNA-based analysis of bacterial diversity in the gut of fungus-cultivating termites (Microtermes and Odontotermes species)(Springer Netherlands, 2013-08-14) Makonde, Huxley M.; Boga, Hamadi I.; Mwirichia, Romano K.; Mackenzie, Lucy; Göker, Markus; Klenk, Hans-PeterThe interaction between termites and their gut symbionts has continued to attract the curiosity of researchers over time. The aim of this study was to characterize and compare the bacterial diversity and community structure in the guts of three termites (Odontotermes somaliensis, Odontotermes sp. and Microtermes sp.) using 16S rRNA gene sequencing of clone libraries. Clone libraries were screened by restriction fragment length polymorphism and representative clones from O. somaliensis (100 out of 330 clones), Odontotermes sp. (100 out of 359 clones) and Microtermes sp. (96 out 336 clones) were sequenced. Phylogenetic analysis indicated seven bacterial phyla were represented: Bacteroidetes, Spirochaetes, Firmicutes, Proteobacteria, Synergistetes, Planctomycetes and Actinobacteria. Sequences representing the phylum Bacteroidetes (>60 %) were the most abundant group in Odontotermes while those of Spirochaetes (29 %) and Firmicutes (23 %) were the abundant groups in Microtermes. The gut bacterial community structure within the two Odontotermes species investigated here was almost identical at the phylum level, but the Microtermes sp. had a unique bacterial community structure. Bacterial diversity was higher in Odontotermes than in Microtermes. The affiliation and clustering of the sequences, often with those from other termites’ guts, indicate a majority of the gut bacteria are autochthonous having mutualistic relationships with their hosts. The findings underscore the presence of termite-specific bacterial lineages, the majority of which are still uncultured.Item 454 Pyrosequencing‑based assessment of bacterial diversity and community structure in termite guts, mounds and surrounding soils(2015-09) Makonde, Huxley M.; Mwirichia, Romano; Osiemo, Zipporah; Boga, Hamadi I.; Klenk, Hans‑PeterTermites constitute part of diverse and economically important termite fauna in Africa, but information on gut microbiota and their associated soil microbiome is still inadequate. In this study, we assessed and compared the bacterial diversity and community structure between termites’ gut, their mounds and surrounding soil using the 454 pyrosequencing-based analysis of 16S rRNA gene sequences. A wood-feeder termite (Microcerotermes sp.), three fungus-cultivating termites (Macrotermes michaelseni, Odontotermes sp. and Microtermes sp.), their associated mounds and corresponding savannah soil samples were analyzed. The pH of the gut homogenates and soil physico-chemical properties were determined. The results indicated significant difference in bacterial community composition and structure between the gut and corresponding soil samples. Soil samples (Chao1 index ranged from 1359 to 2619) had higher species richness than gut samples (Chao1 index ranged from 461 to 1527). The bacterial composition and community structure in the gut of Macrotermes michaelseni and Odontotermes sp. were almost identical but different from that of Microtermes and Microcerotermes species, which had unique community structures. The most predominant bacterial phyla in the gut were Bacteroidetes (40–58 %), Spirochaetes (10–70 %), Firmicutes (17–27 %) and Fibrobacteres (13 %) while in the soil samples were Acidobacteria (28–45 %), Actinobacteria (20–40 %) and Proteobacteria (18–24 %). Some termite gut-specific bacterial lineages belonging to the genera Dysgonomonas, Parabacteroides, Paludibacter, Tannerella, Alistipes, BCf9-17 termite group and Termite Treponema cluster were observed. The results not only demonstrated a high level of bacterial diversity in the gut and surrounding soil environments, but also presence of distinct bacterial communities that are yet to be cultivated. Therefore, combined efforts using both culture and culture-independent methods are suggested to comprehensively characterize the bacterial species and their specific roles in these environments.Item Archaeal Diversity in the Haloalkaline Lake Elmenteita in Kenya(Springer-Verlag, 2009-10-06) Mwirichia, Romano K.; Cousin, Sylvie; Muigai, Ann W.; Boga, Hamadi I.; Stackebrandt, ErkoA non-culture approach was used to study the archaeal diversity in Lake Elmenteita, Kenya. Five different sampling points were selected randomly within the lake. Wet sediments and water samples were collected from each sampling point. In addition, dry mud cake was collected from three points where the lake had dried. DNA was extracted from these samples and the 16S rRNA genes were amplified using primers described to be Domain-specific for Archaea. Eleven clone libraries were constructed using PCR-amplified 16S rRNA genes. A total of 1,399 clones were picked and analysed via ARDRA. 170 ARDRA patterns were unique and the respective clones were selected for sequencing. 149 clones gave analysable sequences. BLAST analysis showed that 49 belong to the Domain Archaea while the others were either chimera or affiliated to eukaryotic taxa. Comparative sequence analysis of archaeal clones affiliated them to a wide range of genera. The order Halobacteriales was represented by members of the genera Natronococcus, Halovivax, Halobiforma, Halorubrum, and Halalkalicoccus. The highest percentage (46%) of the clones, however, belonged to uncultured members of the Domain Archaea in the order Halobacteriales. The results show that the archaeal diversity in the lake could be higher than previously reported.Item Bacteria and Archaea diversity within the hot springs of Lake Magadi and Little Magadi in Kenya(BioMed Central, 2016-06) Mwirichia, Romano K.; Kasili, Remmy W.; Karanja, Edward N.; Makonde, Huxley M.; Boga, Hamadi I.; Kambura, Anne K.Background: Lake Magadi and little Magadi are hypersaline, alkaline lakes situated in the southern part of Kenyan Rift Valley. Solutes are supplied mainly by a series of alkaline hot springs with temperatures as high as 86 °C. Previous culture-dependent and culture-independent studies have revealed diverse groups of microorganisms thriving under these conditions. Previous culture independent studies were based on the analysis of 16S rDNA but were done on less saline lakes. For the first time, this study combined illumina sequencing and analysis of amplicons of both total community rDNA and 16S rRNA cDNA to determine the diversity and community structure of bacteria and archaea within 3 hot springs of L. Magadi and little Magadi. Methods: Water, wet sediments and microbial mats were collected from springs in the main lake at a temperature of 45.1 °C and from Little Magadi “Nasikie eng’ida” (temperature of 81 °C and 83.6 °C). Total community DNA and RNA were extracted from samples using phenol-chloroform and Trizol RNA extraction protocols respectively. The 16S rRNA gene variable region (V4 – V7) of the extracted DNA and RNA were amplified and library construction performed following Illumina sequencing protocol. Sequences were analyzed done using QIIME while calculation of Bray-Curtis dissimilarities between datasets, hierarchical clustering, Non Metric Dimensional Scaling (NMDS) redundancy analysis (RDA) and diversity indices were carried out using the R programming language and the Vegan package. Results: Three thousand four hundred twenty-six and one thousand nine hundred thirteen OTUs were recovered from 16S rDNA and 16S rRNA cDNA respectively. Uncultured diversity accounted for 89.35 % 16S rDNA and 87.61 % 16S rRNA cDNA reads. The most abundant phyla in both the 16S rDNA and 16S rRNA cDNA datasets included: Proteobacteria (8.33–50 %), Firmicutes 3.52–28.92 %, Bacteroidetes (3.45–26.44 %), Actinobacteria (0.98–28.57 %) and Euryarchaeota (3.55–34.48 %) in all samples. NMDS analyses of taxonomic composition clustered the taxa into three groups according to sample types (i.e. wet sediments, mats and water samples) with evident overlap of clusters between wet sediments and microbial mats from the three sample types in both DNA and cDNA datasets. The hot spring (45.1 °C) contained less diverse populations compared to those in Little Magadi (81–83 °C). Conclusion: There were significant differences in microbial community structure at 95 % level of confidence for both total diversity (P value, 0.009) based on 16S rDNA analysis and active microbial diversity (P value, 0.01) based on 16S rRNA cDNA analysis, within the three hot springs. Differences in microbial composition and structure were observed as a function of sample type and temperature, with wet sediments harboring the highest diversity.Item Bacterial Diversity in the Haloalkaline Lake Elmenteita(Springer-Verlag, 2010-06) Mwirichia, Romano K.; Cousin, S.; Muigai, A.W.; Boga, Hamadi I.; Stackebrandt, ErkoLake Elmenteita is one of the alkaline saline lakes within the Kenyan Rift valley. The lake is situated on the floor of the Kenyan Rift Valley at 1,776 m above sea level and has no direct outlet. The microbial diversity of the lake was investigated using a culture-independent approach. Five different sampling points were selected randomly within the lake. Wet sediments and water samples were collected from each sampling point. In addition, dry mud cake was collected from three points where the lake had dried. DNA was extracted from the samples and the 16S rRNA genes amplified using universal primers for Bacteria. Thirteen clone libraries were constructed using the PCR amplified 16S rRNA genes. A total of 1,663 clones were picked. Representative clones were selected using ARDRA technique for sequencing. 655 partial and non-chimeric clone sequences indicated the presence of 37 orders in the Domain Bacteria. Cyanobacteria were the most abundant clones in terms of numbers whereas members of the phylum Firmicutes group were the second in terms of numbers but the most diverse in terms of genera represented. All clones affiliated to the class Betaproteobacteria originated from DNA obtained from the water samples. Analysis using BLAST showed that 93.1% of the sequenced clones had similarity values below 98% to both cultured and as yet uncultured bacteria, resulting in 596 phylotypes. Therefore, it can be concluded that Lake Elmenteita harbours phylogenetically diverse groups of bacteria involved in complex metabolic interactions within the Lake’s ecosystem.Item Characterization of various Bacillus thuringiensis strains having larvicidal activity on Chilo partellus first-instar larvae, after culture on cost-effective medium, in Kenya(2011) Anyika, D.; Boga, Hamadi I.; Mwirichia, Romano K.Bacillus thuringiensis strains are widely used in many larvicidal pest control programs. However, the large-scale production of these biolarvicides is very expensive due to the high cost of the production synthetic medium. In this study, we developed cost-effective media, based on locally available raw materials namely legumes, potato, and whey. The optical density, protein concentration yield, sporulation and Chilo partellus larvicidal action were studied by growing bacterial strains in these waste product and in comparison with the conventional medium (NYSM). Protein concentration yield of 27.60 μg/ ml, spore count of 5.60 × 108 and Chilo partellus larvicidal activity (LC50) of 78 μg/ l against first-instar larvae were obtained with a 72 h culture of this bacterium. Production of Bt Insecticidal Crystal Proteins in NYSM was comparable to the test media and mean values were not significantly different for spore counts: F (media) = 25.19 P>0.01. One-way ANOVA (repeated measures) difference in percentage larval mortalities of Bacillus thuringiensis subspecies kurstaki (F = 26.88, P>0.05) and Bt isolates was not statistically significant. The SDS-PAGE profiles indicated that spore-crystal product from each treatment consisted of proteins with molecular weights of approximately 110-120 kDa and 60-70 kDa. Therefore the investigation suggests that legume, potato and whey-based culture media are more economical for the industrial production of Bt Insecticidal Crystal Proteins.Item Development of cost-effective media for the culture of Chilo partellus larvicide in Kenya(Academic Journals, 2013-03) Anyika, D.; Boga, Hamadi I.; Mwirichia, Romano K.Stem borers (Chilo partellus) are important field insect pests of maize (Zea mays L.) and sorghum (Sorghum bicolor L.) in Africa. They account for more than 30% yield losses depending on the composition of the pest community. C. partellus larvicide like Bacillus thuringiensis have been widely and effectively used in C. partellus control programs, but the industrial production of theses bacilli is expensive. Here we have attempted to develop three cost-effective media, based on legumes, potato, and whey. Growth and production of the insecticidal proteins from these bacteria were satisfactory; protein concentration yields of 27.60 mg/ml, spore counts of 5.60 × 108 CFU/ ml and first-instar Chilo partellus larvicidal activity (LC50) of 78 μg/l were obtained with a 72 h culture of this bacterium. Therefore, this investigation suggests that legume, potato and whey-based culture media are more economical and effective for the industrial production of B. thuringiensis insecticidal crystal proteins.Item Diversity of Termitomyces Associated with Fungus- Farming Termites Assessed by Cultural and Culture- Independent Methods(2013) Makonde, H.M.; Boga, Hamadi I.; Osiemo, Z.; Mwirichia, Romano K.; Stielow, J.B.; Go¨ ker, Markus; et al.Background: Fungus-cultivating termites make use of an obligate mutualism with fungi from the genus Termitomyces, which are acquired through either vertical transmission via reproductive alates or horizontally transmitted during the formation of new mounds. Termitomyces taxonomy, and thus estimating diversity and host specificity of these fungi, is challenging because fruiting bodies are rarely found. Molecular techniques can be applied but need not necessarily yield the same outcome than morphological identification. Methodology: Culture-dependent and culture-independent methods were used to comprehensively assess host specificity and gut fungal diversity. Termites were identified using mitochondrial cytochrome oxidase II (COII) genes. Twenty-three Termitomyces cultures were isolated from fungal combs. Internal transcribed spacer (ITS) clone libraries were constructed from termite guts. Presence of Termitomyces was confirmed using specific and universal primers. Termitomyces species boundaries were estimated by cross-comparison of macromorphological and sequence features, and ITS clustering parameters accordingly optimized. The overall trends in coverage of Termitomyces diversity and host associations were estimated using Genbank data. Results and Conclusion: Results indicate a monoculture of Termitomyces in the guts as well as the isolation sources (fungal combs). However, cases of more than one Termitomyces strains per mound were observed since mounds can contain different termite colonies. The newly found cultures, as well as the clustering analysis of GenBank data indicate that there are on average between one and two host genera per Termitomyces species. Saturation does not appear to have been reached, neither for the total number of known Termitomyces species nor for the number of Termitomyces species per host taxon, nor for the number of known hosts per Termitomyces species. Considering the rarity of Termitomyces fruiting bodies, it is suggested to base the future taxonomy of the group mainly on well-characterized and publicly accessible cultures.Item Evaluation of prokaryotic diversity of five hot springs in Eritrea(BioMed Central, 2017-09) Ghilamicael, Amanuel M.; Budambula, Nancy; Anami, Sylvester E.; Mehari, Tadesse; Boga, Hamadi I.Background: Total community rDNA was used to determine the diversity of bacteria and archaea from water, wet sediment and microbial mats samples of hot springs in the Eastern lowlands of Eritrea. The temperatures of the springs range from 49.5 °C to 100 °C while pH levels varied from 6.97 to 7.54. Akwar and Maiwooi have high carbonate levels. The springs near the seashore, Garbanabra and Gelti, are more saline with higher levels of sodium and chlorides. Elegedi, situated in the Alid volcanic area, has the highest temperature, iron and sulfate concentrations. Results: The five hot springs shared 901 of 4371 OTUs recovered while the three sample types (water, wet sediment and microbial mats) also shared 1429 OTUs. The Chao1 OTU estimate in water sample was significantly higher than the wet sediment and microbial mat samples. As indicated by NMDS, the community samples at genus level showed location specific clustering. Certain genera correlated with temperature, sodium, carbonate, iron, sulfate and ammonium levels in water. The abundant phyla included Proteobacteria (6.2–82.3%), Firmicutes (1.6–63.5%), Deinococcus-Thermus (0.0–19.2%), Planctomycetes (0.0–11.8%), Aquificae (0.0–9.9%), Chlorobi (0.0–22.3%) and Bacteroidetes (2.7–8.4%). Conclusion: There were significant differences in microbial community structure within the five locations and sample types at OTU level. The occurence of Aquificae, Deinococcus-Thermus, some Cyanobacteria and Crenarchaeota were highly dependent on temperature. The Halobacterium, unclassified Thaumarchaeota, Actinobacteria and Cyanobacteria showed significant correlation with salinity occurring abundantly in Garbanabra and Gelti. Firmicutes and unclassified Rhodocylaceae were higher in the microbial mat samples, while Archaea were prominent in the wet sediment samples.Item Isolation and characterisation of bacteria from the haloalkaline Lake Elmenteita, Kenya(Springer, 2010-04) Mwirichia, Romano K.; Muigai, A.W.; Tindall, B.; Boga, Hamadi I.; Stackebrandt, E.Culture-independent studies show that soda lake environments harbour diverse groups of bacteria and archaea. In this study different enrichment and isolation media were used in an attempt to isolate novel groups of bacteria from Lake Elmenteita. Different media were prepared using filter-sterilised water from the lake. The isolates recovered were purified on tryptic soy agar supplemented with 1% sodium carbonate and 4% sodium chloride. Phylogenetic analysis of 181 partial 16S rRNA gene sequences with excellent quality showed that the majority of the isolates were affiliated to the class Gammaproteobacteria and to the genus Bacillus. Isolates from the genus Halomonas and Bacillus constituted 37 and 31% of the total sequenced isolates, respectively. Other groups recovered were related to Marinospirillum, Idiomarina, Vibrio, Enterococcus, Alkalimonas, Alkalibacterium, Amphibacillus, Marinilactibacillus and the actinobacteria Nocardiopsis and Streptomyces. Fifty-one different genera were represented with 31 and 15 cultures scoring with their nearest neighbour similarities below 98 and 97%, respectively. Some novel taxa were identified which had not been isolated previously from the soda environment. The results show that the use of different media with varying compositions can help retrieve novel bacterial diversity from the soda lake environment.Item Isolation and characterization of actinobacteria from Lake Magadi, Kenya(Academic Journals, 2013-08-09) Ronoh, Regina C.; Budambula, Nancy; Mwirichia, Romano K.; Boga, Hamadi I.Actinobacteria are ubiquitous and have been detected in terrestrial and aquatic ecosystems. Although, various studies have focused on the ecology of this phylum, data on the ecology of actinobacteria endemic to soda lakes are scanty. This study aimed to determine actinobacterial diversity in Lake Magadi. Four different sampling points were selected randomly within the lake to cover a broad range of sample diversity. Wet sediments and water samples were collected from each sampling point. Good success in isolation of actinobacteria was obtained using a variety of strategies designed to select against fast growing bacteria. Serially diluted samples were plated on growth media containing complex substrates such as malt and chitin. The media was prepared using sterile lake water and pH kept at 8 which is high for most bacteria. DNA was extracted from the isolates and the 16S rRNA genes amplified using primers described to be domain specific for actinobacteria. The isolates were characterized both physiologically and biochemically and were screened for the presence of polyketide synthase-1 genes. The amplified 16S rRNA gene sequences were used for sequence analysis to identify the isolates and establish their phylogeny. Four actinobacteria isolates affiliated with the genera Rhodococcus, Dietzia, Microbacterium and Nocardia were obtained. BLAST analysis showed that all the isolates had between 97 and 99% similarity to their close relatives. Three of the isolates were positive for polyketide synthase genes. These results increase the number of actinobacteria isolates from soda lakes for potential use in biotechnology research.Item Isolation and characterization of actinobacteria from Lake Magadi, Kenya(Academic Journals, 2013-08-09) Ronoh, Regina C.; Budambula, Nancy; Mwirichia, Romano K.; Boga, Hamadi I.Actinobacteria are ubiquitous and have been detected in terrestrial and aquatic ecosystems. Although, various studies have focused on the ecology of this phylum, data on the ecology of actinobacteria endemic to soda lakes are scanty. This study aimed to determine actinobacterial diversity in Lake Magadi. Four different sampling points were selected randomly within the lake to cover a broad range of sample diversity. Wet sediments and water samples were collected from each sampling point. Good success in isolation of actinobacteria was obtained using a variety of strategies designed to select against fast growing bacteria. Serially diluted samples were plated on growth media containing complex substrates such as malt and chitin. The media was prepared using sterile lake water and pH kept at 8 which is high for most bacteria. DNA was extracted from the isolates and the 16S rRNA genes amplified using primers described to be domain specific for actinobacteria. The isolates were characterized both physiologically and biochemically and were screened for the presence of polyketide synthase-1 genes. The amplified 16S rRNA gene sequences were used for sequence analysis to identify the isolates and establish their phylogeny. Four actinobacteria isolates affiliated with the genera Rhodococcus, Dietzia, Microbacterium and Nocardia were obtained. BLAST analysis showed that all the isolates had between 97 and 99% similarity to their close relatives. Three of the isolates were positive for polyketide synthase genes. These results increase the number of actinobacteria isolates from soda lakes for potential use in biotechnology research.Item Isolation and characterization of actinobacteria from Lake Magadi, Kenya(2013-05-29) Budambula, N. L. M.; Ronoh, Regina C.; Mwirichia, Romano K.; Boga, Hamadi I.Actinobacteria are ubiquitous and have been detected in terrestrial and aquatic ecosystems. Although, various studies have focused on the ecology of this phylum, data on the ecology of actinobacteria endemic to soda lakes are scanty. This study aimed to determine actinobacterial diversity in Lake Magadi. Four different sampling points were selected randomly within the lake to cover a broad range of sample diversity. Wet sediments and water samples were collected from each sampling point. Good success in isolation of actinobacteria was obtained using a variety of strategies designed to select against fast growing bacteria. Serially diluted samples were plated on growth media containing complex substrates such as malt and chitin. The media was prepared using sterile lake water and pH kept at 8 which is high for most bacteria. DNA was extracted from the isolates and the 16S rRNA genes amplified using primers described to be domain specific for actinobacteria. The isolates were characterized both physiologically and biochemically and were screened for the presence of polyketide synthase-1 genes. The amplified 16S rRNA gene sequences were used for sequence analysis to identify the isolates and establish their phylogeny. Four actinobacteria isolates affiliated with the genera Rhodococcus, Dietzia, Microbacterium and Nocardia were obtained. BLAST analysis showed that all the isolates had between 97 and 99% similarity to their close relatives. Three of the isolates were positive for polyketide synthase genes. These results increase the number of actinobacteria isolates from soda lakes for potential use in biotechnology research.Item Isolation and characterization of bacteria isolates from soil feeding termites and soil from Juja and Kakamega forest in Kenya(2010) Ntabo, R.; Boga, Hamadi I.; Muigai, A.; Mwirichia, R.In the last several years information on the gut ecosystem of termites has continued to be gathered. Most studies have been focused on wood feeding termites but studies on soil feeders remain sparse owing to their difficulty of establishing permanent laboratory cultures. The aim of this study was to isolate, characterize and identify bacteria resident in the soil feeding termite gut, mound and parent soil of Cubitermes species with the potential to produce antibiotics and enzymes for industrialization. The samples were collected from kakamega forest from two sites Kalunya Glade and Lirhanda Hill. The study was also extended to the soils found in Juja. Hundred and thirty seven (137) isolates were cultivated and isolated using dilute nutrient agar media and screened for their antagonistic effects on various test organisms. Fifty one percent of the isolates were antagonist to Escherichia coli. Fifty seven percent of the isolates were antagonists to Bacillus subtilis while 55% of the isolates were antagonist to Candida albicans. Enzymatic activities of the isolates showed that 65% of the total isolates were starch degraders, 54% were casein degraders and 68% of the isolates were able to liquefy gelatin. Eleven percent of the isolates were cellulose degraders the majority of which were obtained from termite gut and mound. Isolates from Juja soil had the highest number of non degraders as compared to Kakamega Forest soils. The isolates were characterized using morphological, biochemical and molecular methods. Phylogenetic analysis of amplified 16S rRNA gene sequence revealed majority of the isolates were closely related to Bacillus and Brachybacterium species and had showed invitro antagonistic effects. Gram negative bacterial isolates obtained were closely related to Pseudomonas species. In conclusion, the isolates were potential antibiotic producers with varying ability to degrade gelatin, casein, and cellulose an indication of the role they play in their habitatItem Isolation and characterization of bacterial isolates from Lake Magadi(2012) Kambura, A.K.; Mwirichia, Romano K.; Ngaira, J.; Boga, Hamadi I.Microorganisms from soda lakes have attracted attention as a possible source of novel enzymes and metabolites for use in industrial applications. Isolation and characterization of bacteria from Kenyan soda lakes has been done mainly in Lakes Elmenteita, Bogoria and Nakuru. Only a few studies have been documented on Lake Magadi, a hyper saline lake with up to 30% salinity levels. This study sought to isolate alkaliphilic bacteria from Lake Magadi that could produce novel enzymes and antimicrobial compounds, and document for further exploitation. Nearly 55 isolates were obtained using different media prepared with filter-sterilised water from the lake, which were characterized and screened for production of extracellular enzymes and/or antimicrobial compounds. Bacteria retrieved grew well at pH ranging from 5 – 10, temperature range of 25 – 50 oC and sodium chloride range of 0- 30 %. The isolates produced amylases, lipases, proteases and esterases and exhibited a range of inhibitory effects on various test organisms. Analysis of partial sequences of 16S rRNA genes using Blast showed that 80 % of the isolates were affiliated to the genus Bacillus, while 20% were affiliated to members of Gammaproteobacteria. Five (5) isolates showed identity of 95 - 97 % similarity with the previously known sequences and could represent novel bacterial species, while 4 isolates had a sequence identity of 80 - 93% similarity to known organisms, and could represent novel genera. This study demonstrated that the extreme environment of Lake Magadi harbors novel alkaliphilic bacteria with potential for production of enzymes and antimicrobial compounds.Item Isolation and characterization of some gut microbial symbionts from fungus-cultivating termites (Macrotermes and Odontotermes spp.)(Academic Journals, 2016-07) Muwawa, Edith M.; Budambula, Nancy; Osiemo, Zipporah L.; Boga, Hamadi I.; Makonde, Huxley M.Microbiota of termites is crucial for nitrogen cycle activities and degradation of recalcitrant components of plant biomass that influence soil structure and carbon mineralization in tropical and subtropical regions. The aim of this study was to isolate and characterize gut bacteria that may be potentially associated with nitrogen metabolism from two fungus-feeding termites (Macrotermes and Odontotermes spp.). Twenty termites from the intact colony of each termite species were aseptically degutted. Gut homogenate was inoculated and cultured on selective media for the isolation of pure bacteria. Pure bacterial isolates were characterized using their morphological, biochemical and molecular characters. DNA was extracted from the isolates, polymerase chain reaction (PCR) amplified and sequenced. The 16S rDNA gene sequences were blastn analyzed against the Genbank database and phylogenetic analysis was performed using MEGA 5 software. All forty-six isolates reacted positive for the ammonifying, nitrate, catalase and nitrogenase tests. Phylogenetic analysis grouped the isolates into three phyla: Firmicutes, Proteobacteria and Actinobacteria. Isolates were affiliated with the genera Pseudomonas, Citrobacter, Enterobacter, Proteus, Klebssiella, Bacillus, Staphylococcus, Rhodococcus and Micrococcus. The results confirm that termites harbor diverse gut bacterial groups that have different physiological/enzymatic activities and might have functional implications in the termitemicrobe symbiotic association.Item Isolation and characterization of some gut microbial symbionts from fungus-cultivating termites (Macrotermes and Odontotermes spp.)(2016-07) Budambula, Nancy; Muwawa, Edith M.; Osiemo, Zipporah L.; Boga, Hamadi I.; Makonde, Huxley M.Microbiota of termites is crucial for nitrogen cycle activities and degradation of recalcitrant components of plant biomass that influence soil structure and carbon mineralization in tropical and subtropical regions. The aim of this study was to isolate and characterize gut bacteria that may be potentially associated with nitrogen metabolism from two fungus-feeding termites (Macrotermes and Odontotermes spp.). Twenty termites from the intact colony of each termite species were aseptically degutted. Gut homogenate was inoculated and cultured on selective media for the isolation of pure bacteria. Pure bacterial isolates were characterized using their morphological, biochemical and molecular characters. DNA was extracted from the isolates, polymerase chain reaction (PCR) amplified and sequenced. The 16S rDNA gene sequences were blastn analyzed against the Genbank database and phylogenetic analysis was performed using MEGA 5 software. All forty-six isolates reacted positive for the ammonifying, nitrate, catalase and nitrogenase tests. Phylogenetic analysis grouped the isolates into three phyla: Firmicutes, Proteobacteria and Actinobacteria. Isolates were affiliated with the genera Pseudomonas, Citrobacter, Enterobacter, Proteus, Klebssiella, Bacillus, Staphylococcus, Rhodococcus and Micrococcus. The results confirm that termites harbor diverse gut bacterial groups that have different physiological/enzymatic activities and might have functional implications in the termitemicrobe symbiotic association.Item Isolation, characterization and identification of Diazinon degrading bacteria from the soil and gut of macrotermes(2013) Ogot, Hellen A.; Boga, Hamadi I.; Budambula, Nancy; Tsanuo, Muniru; Andika, Darius O.Diazinon degrading bacteria were isolated from the soil and gut of fungus cultivating termites Macrotermes michaelseni using MM7 media supplemented with pesticide as the sole source of carbon and energy. The isolates were gram negative rods the isolates from the soil were designated DS2, DS3 and DS5 while from termite gut was designated DT2. 16S rRNA gene sequence analysis showed that diazinon degrading isolate DS2 (from the soil) is closely related to Achromobacter xylosoxidan AF508101 (100%), isolate DT2 from termite gut is closely related to Klebsiella oxytoca AB004754 (99.7%). Whereas isolates DS3 and DS5 , both from the soil are closely related to p., AY082447 (99%). The ability of the isolates to degrade diazinon highlights their potential to be used in bioremediation.Item Physical and Chemical Characteristics of Five Hot Springs in Eritrea(IISTE, 2017-07) Ghilamicael, Amanuel M.; Boga, Hamadi I.; Anami, Sylvester E.; Mehari, Tadesse; Budambula, NancyEritrea has a number of hot springs whose physicochemical characteristics are not documented. This study examined the thermal and chemical features of five hot springs located in the eastern escarpment of Eritrea. Field data and water samples were collected from five hot springs namely; Akwar and Maiwooi near Gahtelai, Garbanabra and Gelti near Irafayle at the Gulf of Zula and Elegedi in Alid volcanic center. The water temperatures at source varied from 49.5°C to 100°C while pH levels ranged from 6.97 to 7.54. Elegedi had significantly higher temperature (p < 0.05) than the other four hot springs. Strong correlation was observed between electrical conductivity (EC), total dissolved solid (TDS), salinity, sodium, potassium, calcium and chloride (R2 > 0.9) as well as between temperature and sulphate levels (R2 = 0.96). Evident clustering was noted at p < 0.05, using Non-metric multidimensional scaling (NMDS), between the three locations of the hot springs. Akwar and Maiwooi, situated close to each other, clustered together, Garbanabra and Gelti, which were characterized by higher salinity levels, formed a separate cluster. Elegedi, characterized by high temperature (100°C), sulphate (979.7 mg/l) and NH4 + (196.33 mg/l) levels, clustered separately. Akwar and Maiwooi had high bicarbonate (345 mg/l and 393 mg/l) and fluoride (8.20 mg/l and 6.48 mg/l) levels which are above WHO limits. Electrical conductivity (23,133 mS/cm), total dissolved solid (15,552 mg/l), sodium (3,800 mg/l), potassium (198 mg/l), calcium (1,653 mg/l) and chloride (5,946 mg/l) levels in Garbanabra and Gelti hot springs exceeded WHO limits. Bromine (74.8 mg/l in Garbanabra and 45.2 mg/l in Gelti) and boron (2.21 mg/l in Garbanabra and 1.55 mg/l in Gelti) levels were also above standard limits set for potable water. Maiwooi (1.20) and Elegedi (1.10) were depositional while Akwar water (-0.71) was slightly corrosive. The corrosive nature of the water sample from Akwar, is a public health concern. The waters from the five Eritrean hot springs are thus not fit for human consumption. In addition, the use of thermal spring water for recreational purposes should be closely monitored.