Aims: The study was aimed to, isolate, screen and characterize the heterotrophic lipid producing bacteria from various oil and fat contaminated sites. Additionally, the study was focused to evaluate the influence of some carbon and nitrogen sources on bacterial culture.
Place and Duration of Study: The current study was carried out in the Department of Environmental Science and Engineering, Lab no. 211 (Bioenergy and bioremediation Lab) Guru Jambheshwar University of Science and Technology, Hisar. Duration of study from August 2014- January 2015.
Methodology: Soil samples were collected from Hisar, Sirsa (Haryana) and waste water sludge from Guru Jambheshwar University of Science and Technology, Hisar. Isolation and purification of filamentous bacterial strains was done by simple plate streak plate method, followed by screening of bacterial strains by Sudan black/Nile Red dye. Genomic DNA was extracted from bacterial strain using Cetyl trimethyl ammonium bromide (CTAB) method. PCR product was sequenced by 16sRNA approach. In batch flasks study, effect of various carbon and nitrogen sources on lipid and biomass of Rhodococcus opacus and Gordonia alkanivorans were evaluated by using gravimetric Bligh and dyer method.
Results: Filamentous bacterial strains were initially isolated using selective culture media, further these oleaginous bacterial strains were screened out on the basis of growth rate and lipid content (dcw%) and employed Nile red and Sudan black staining for detection of neutral lipids in cells. The biochemical behavior (biomass production, accumulation of total lipid) and substrate uptake by two oleaginous bacteria has been studied. Furthermore, Rhodococcus sp. and Gordonia sp. were cultivated under various carbon and nitrogen sources. Significant differences in the process of lipid accumulation and biomass yield as related to the carbon, nitrogen sources used were observed for both microorganisms. Although glucose containing MSM medium favours production of biomass yield 1.81±0.026 gL-1 and 1.63±0.032 gL-1 with corresponding high lipid content 16.78%,17.05% in Rhodococcus opacus as well as Gordonia alkanivorans respectively. Among Various tested nitrogen sources, Ammonium sulphate was found to be best nitrogen source for cultivation of Rhodococcus opacus and Gordonia alkanivorans (P≤0.05) indicating higher lipid content of 16.55%, 17.01%.
Conclusion: Filamentous bacteria have capacity to accumulate substantial amount of oil. Nile Red and Sudan black staining dye was found to be effective method for prescreening of oleaginous bacteria. Glucose and Ammonium sulphate proved to be suitable carbon and nitrogen source for culturing of Rhodococcus opacus and Gordonia alkanivorans.
Five improved varieties of Glycine max (TGX 1987-62F, TGX 1485-1D, TGX 1448-2E, TGX 1987-10F and TGX 1835-10E) consumed in Samaru community, Zaria-Nigeria were analyzed for their proximate composition and mineral contents using standard methods. The results show that TGX 1835-10E has significantly (p<0.05) higher protein compared to the other varieties. Carbohydrates and ash contents did not differ significantly (p>0.05) between the varieties. The lipid and crude fiber content were significantly (p<0.05) high in TGX 1987-62F and TGX 1448-2E varieties respectively. Moisture content was significantly (p<0.05) high in TGX 1448-2E and TGX 1485-1D varieties. The mineral analysis showed no significant (p>0.05) difference in the Copper (Cu) content of all the varieties. Potassium (K) and Iron (Fe) contents were significantly high in TGX 1485-1D variety while Calcium (Ca), Magnesium (Mg) and Zinc (Zn) contents were significantly (p<0.05) high in TGX 1987-62F, TGX 1835-10E and TGX 1987-10F, respectively. The results show that none of the test varieties is outstandingly different.
Background: Microalgae have the potential to produce natural bioactive compounds, which are difficult to be produced by chemical synthesis. These compounds also possess diverse biological activities, such as antibacterial, anti-inflammatory, anti-atherosclerotic and anti-carcinogenic activities.
Objective: The purposes of the current study were to use a simple and accurate Thin layer chromatography (TLC) bioautographic method for detection and isolation of antibacterial compound from the complex cyanobacterial extract and the characterization of the isolated compound.
Materials and Methods: Polar and non-polar extracts of cyanobacterium Anabaena oryzae were screened for antibacterial activity against various Gram-positive and Gram-negative bacterial species using agar well diffusion method. The mode of action of methanolic extract on pathogenic bacteria was examined using scanning electron microscopy, Thin layer chromatography-direct bioautography (TLC-DB) was applied for the first time in detection and isolation of the antimicrobial compound in cyanobacterial extract. The target band was purified by silica gel column chromatography and antibacterial compound was isolated. The isolated compound was characterized using IR and mass spectroscopy.
Results: The methanolic extract had the highest biological activity against Escherichia coli, MIC 0.05 µg/ml. Scanning electron microscopy revealed a shortening and swelling of the E. coli cells, and multiple blisters and bubbles formed on their surface. One compound with antibacterial activity was isolated using (TLC-BD) and column chromatography. Infrared spectra (IR) indicated that the isolated compound was phenolic compound. Mass spectroscopy indicated that its molecular weight was 443.38.
Conclusion: It was concluded that cyanobacteria Anabaena oryzae are metabolically very diverse group and a promising group of organisms for research on medicines discovery. It was also concluded that (TLC-DB) is very useful in the isolation and identification of compounds with antimicrobial activity from biological extract.
Changes in Amino Acids, Anti-Nutrients and Functional Properties of African Yam Bean Flour Caused by Variation in Steeping Time Prior to Autoclaving
Background and Aim: Legume seeds are usually steeped in water or bicarbonate solution before further processing and this has some effect on the constituents and functional properties of the flour. The present study was to evaluate the effect of steeping time in 0.50% solution of unripe plantain peel ash prior to autoclaving on the amino acids, anti-nutrients and functional properties of African yam bean flour.
Study Design: Analysis of variance (ANOVA) was carried out.
Place and Duration: Department of Food Science and Technology, University of Uyo, Akwa Ibom State, Nigeria, from November 2016 to May 2017.
Methodology: African yam bean seeds were sorted, washed and divided into four portions of 500g each. Portion I was not steeped and served as control sample while portions 2, 3 and 4 were steeped in 0.50% solution of unripe plantain peel ash (1:5w/v) at ambient temperature (27±2ºC) for 24, 48 and 72h respectively. Both the unsteeped and steeped portions were separately autoclaved, dehulled, oven dried, milled and sieved to obtain the flours used for analysis.
Results: The result revealed that all the parameters varied with steeping time. The total amino acids and total essential amino acids increased from 75.52g/100g and 30.07g/100g in the flour from unsteeped seeds to 80.29g/100g and 32.87g/100g respectively in the flour from the seeds that were steeped for 72h. Phytate, tannin, trypsin inhibitor, raffinose, stachyose, bulk density, water absorption capacity and swelling index decreased while oil absorption and foaming capacities increased with steeping time. Percentage reduction of phytate, tannin, trypsin inhibitor, raffinose and stachyose after 72h steeping were 80, 86, 98, 97 and 94%, respectively.
Conclusion: The treatment caused significant (p<0.05) reduction in anti-nutrients and flatulence causing factors and enhanced amino acid profile of the flour.
The biostimulation of atrazine-impacted soil using cassava peel waste (CPW) considering the associated soil bacteria was assessed over a period of seven (7) weeks. The study was carried out at the Teaching and Research Farm of the Faculty of Agriculture, University of Port Harcourt, Port Harcourt, Rivers State, Nigeria. The aim of this work was to enhance indigenous soil bacteria in the biodegradation of atrazine through biostimulation using organic wastes. To achieve this, the physicochemical properties of the soil (before and after treatments) and the basic proximate mineral elements of the organic waste was determined before application using standard analytical methods. The bacterial characteristic and pH of the soil treated with CPW, CPW+ATZ, ATZ, and CONTROL (no treatment) were assessed using culture-dependent and standard analytical technique respectively. The study provided adequate evidence that the study site was naturally endowed with requisite bacteria (Acinetobacter sp., Enterobacter sp., Pseudomonas sp., and Bacillus sp.) with potential enzyme repertoire for atrazine degradation. The addition of organic amendment improved the physicochemical status of the impacted soil which culminated to significant (P<0.05) increase in soil microbial population and diversity. The study also showed that pollutants (atrazine) at a tolerable level can improve bacterial population (as a result of the proliferation of naturally selected degraders) but reduce bacterial diversity. This was observed in the treatment, ATZ which had the least bacterial diversity but with the highest bacterial density (35.00±4.24×108cfu/g) at week 6. Although some bacteria are good degraders of herbicides in the soil, however, it may require some amendments in order to stimulate them to degrade pollutants. This work showed that the organic waste used in this study was a potential stimulatory agent that enhanced the growth of indigenous atrazine-degrading soil bacteria; hence can serve as an improved method of waste management and potential soil remediation approach.
