Distribution of Heterotrophic and Nitrogen fixing Rhizobacteria in Irrigation Sites of Lake Alau Borno State Northeastern Nigeria

This study was conducted to know the population of rhizobacteria in both irrigation and non-irrigation sites of the dam. The dense population of these organism indirectly promote plant growth and development. Five sites (A, B, C, D and E) were used to collect soil samples randomly and transported to the laboratory for analysis. Total heterotrophic bacterial count was done using nutrient agar (NA) and nitrogen fixing bacteria was counted using Ashbey’s media (AM). The result shows that highest number of total heterotrophic bacteria in site C (46.0×106) cfu/g in irrigation site whereas higher count in non-irrigation site was (13.0×106) site D, the nitrogen fixing bacterial count in irrigation site was higher at site E with (12.0×106) and for the non-irrigation site was higher at site D with (14.0×106) The total heterotrophic bacteria isolated in the soil sample are the species of Bacillus alvei, Bacillus alvei, Bacillus cereus, Bacillus cereus, Pseudomonas putida, Klebsiella aeruginosa and Enterobacter aeruginosa. Likewise, the Nitrogen fixing bacteria isolated are the species of Rhizobium leguminosarum, Klebsiella pneumonia, Bacillus lentus, Azotobacter nigricans, Azotobacter tropicalis, Azotobacter spp, and Azotobacter tropicalis. The long history of agricultural activities in the lake area has directly influenced the diversity of microbial population in the area.

Anthill Inhibiting Bacteria, a Promising Source of Bio Efficacy

The investigation into soil bacteria has been widely studied and becoming increasingly appreciated as an exceptional reservoir of unique naturally occurring biologically active metabolites with pharmaceutical applications. This article aimed to isolate, identify and biochemically characterize antibiotic-producing bacteria from anthill soils in the permanent site of Ibrahim Badamasi Babangida University, Lapai (IBBUL), Niger State, Nigeria. The sum of ten samples were collected from five sampling sites, the sampling was done in threefold (morning, noon and evening) and analyzed adopting standard microbiological protocols. The obtained result revealed that the total bacteria count in the morning ranges from 2.1×107 cfu/mL to 1.4×106 cfu/mL, noon count ranges from 3.1×107 to 2.6×106 cfu/mL while evening count was in the range of 2.1×107 cfu/mL to 1.7×106 cfu/mL. A total number of five (5) bacteria were isolated as Staphylococcus aureus, Staphylococcus epidermidis, Bacillus subtilis, Bacillus lentus and Micrococcus reseus. The total prevalence of the bacterial isolates in the morning, noon and evening were calculated as B. subtilis (109.08%), S. epidermidis (36.36%), M. reseus (36.36%), B. lentus (63.63%), and S. aureus (54.54%) respectively. These isolates were further assayed against Escherichia coli, Salmonella typhi, Klebsiella sp. and Staphylococcus aureus. The antibacterial outcome showed that two (2) (40%) anthill isolates exhibited antibacterial activity against three (3) tested bacteria (Escherichia coli, Salmonella typhi and Staphylococcus aureus). This research study has showcased that the production of inhibitory substances are common among some of the bacterial strains isolated from anthills.

Optimizing and purifying extracellular amylase from soil bacteria to inhibit clinical biofilm-forming bacteria

Background Bacterial biofilms have become a major threat to human health. The objective of this study was to isolate amylase-producing bacteria from soil to determine the overall inhibition of certain pathogenic bacterial biofilms. Methods We used serial dilution and the streaking method to obtain a total of 75 positive amylase isolates. The starch-agar plate method was used to screen the amylolytic activities of these isolates, and we used morphological and biochemical methods to characterize the isolates. Optimal conditions for amylase production and purification using Sephadex G-200 and SDS-PAGE were monitored. We screened these isolates’ antagonistic activities and the purified amylase against pathogenic and multi-drug-resistant human bacteria using the agar disk diffusion method. Some standard antibiotics were controlled according to their degree of sensitivity. Finally, we used spectrophotometric methods to screen the antibiofilm 24 and 48 h after application of filtering and purifying enzymes in order to determine its efficacy at human pathogenic bacteria. Results The isolated Bacillus species were Bacillus megaterium (26.7%), Bacillus subtilis (16%), Bacillus cereus (13.3%), Bacillus thuringiesis (10.7%), Bacillus lentus (10.7%), Bacillus mycoides (5.3%), Bacillus alvei (5.3%), Bacillus polymyxa (4%), Bacillus circulans (4%), and Micrococcus roseus (4%). Interestingly, all isolates showed a high antagonism to target pathogens. B. alevi had the highest recorded activity (48 mm) and B. polymyxa had the lowest recorded activity (12 mm) against Staphylococcus aureus (MRSA) and Escherichia coli, respectively. On the other hand, we detected no antibacterial activity for purified amylase. The supernatant of the isolated amylase-producing bacteria and its purified amylase showed significant inhibition for biofilm: 93.7% and 78.8%, respectively. This suggests that supernatant and purified amylase may be effective for clinical and environmental biofilm control. Discussion Our results showed that soil bacterial isolates such as Bacillus sp. supernatant and its purified amylase are good antibiofilm tools that can inhibit multidrug-resistant former strains. They could be beneficial for pharmaceutical use. While purified amylase was effective as an antibiofilm, the isolated supernatant showed better results.

Conformational heterogeneity of Savinase from NMR, HDX-MS and X-ray diffraction analysis

Background Several examples have emerged of enzymes where slow conformational changes are of key importance for function and where low populated conformations in the resting enzyme resemble the conformations of intermediate states in the catalytic process. Previous work on the subtilisin protease, Savinase, from Bacillus lentus by NMR spectroscopy suggested that this enzyme undergoes slow conformational dynamics around the substrate binding site. However, the functional importance of such dynamics is unknown. Methods Here we have probed the conformational heterogeneity in Savinase by following the temperature dependent chemical shift changes. In addition, we have measured changes in the local stability of the enzyme when the inhibitor phenylmethylsulfonyl fluoride is bound using hydrogen-deuterium exchange mass spectrometry (HDX-MS). Finally, we have used X-ray crystallography to compare electron densities collected at cryogenic and ambient temperatures and searched for possible low populated alternative conformations in the crystals. Results The NMR temperature titration shows that Savinase is most flexible around the active site, but no distinct alternative states could be identified. The HDX shows that modification of Savinase with inhibitor has very little impact on the stability of hydrogen bonds and solvent accessibility of the backbone. The most pronounced structural heterogeneities detected in the diffraction data are limited to alternative side-chain rotamers and a short peptide segment that has an alternative main-chain conformation in the crystal at cryo conditions. Collectively, our data show that there is very little structural heterogeneity in the resting state of Savinase and hence that Savinase does not rely on conformational selection to drive the catalytic process.

Application of Bioremediation Techniques as a Potent Input for the Decontamination of Bitumen-Polluted Water

Large deposits of natural bitumen are found in some areas of Ondo State, Nigeria. Although the mineral is still unexploited, its seepage is enough to negatively influence the environment, especially water resources. This work was designed to determine the potential of four Bitumen Utilizing Microbes (BUM) for the purification of Bitumen-Polluted Water (BPW). BUM were screened differently with a control on the BPW drawn from the affected communities. The bitumen’s degradation was determined using a supplemented enrichment medium with a sample of the BPW, and the growth was monitored by taking temperature readings, pH values, the optical density at 600 nm, and the total viable count (TVC) on days 7, 14, 21 and 28 respectively. The bitumen removal rate varied with the time of the incubation until after the third week, when the lack of nutrients supposedly set in and toxic metabolites started building up, which slowed down the process. The BUMs were identified as Bacillus firmus, Bacillus lentus, Pseudomonas aeruginosa, and Bacillus alvei. The bitumen removal trend showed that Pseudomonas aeruginosa > Bacillus firmus >Bacillus lentus > Bacillus alvei and the control the least amount of removal.

Determination of Tolerance Potentials of Some Bacteria Species to Heavy Metals Isolated from Contaminated Gold Mining Soil in Abare, Zamfara State

This aim of this research was to determine the tolerance ability of Bacillus lentus, Bacillus firmus, and Pseudomonas aeruginosa. The soil sample was analysed for it heavy metal content lead was found to be in abundance beyond tolerable limit followed by cupper. Several bacterial specie were also isolated and identified from the sample and some selected species were tested for their tolerance ability in different heavy metal concentration, It was recorded that pseudomonas aeruginosa was tolerant to lead (Pb) at 800 mgl-1 Bacillus lentus to cupper at 860 mgl -1 and Bacillus firmus to chromium at 1000mgl-1. It was concluded that despite the toxicity of some heavy metals some bacterial specie were still able to withstand the environment.