Open Access Original Research Article

Antimicrobial Evaluation of Biologically Synthesized Silver Nanoparticles using Aqueous Peel Extracts of Guava (Psidium guavaja) and Pumpkin (cucurbita pepo)

M. Tasiu, Y. Abdulmumin, T. M. Abdulmumin, M. Murtala, A. Shehu, A. L. Abubakar, S. Zainab, R. K. Mustapha, S. S. Binta

Asian Journal of Biotechnology and Genetic Engineering, Page 20-29

Introduction: Green nanoparticle synthesis is a new field of nanotechnology that uses ecologically friendly resources such as entire cells, metabolites, agricultural waste such as peel, or extracts from plants and microbes to make metallic nanoparticles. In this study, silver nanoparticles were synthesized from aqueous extracts of Psidium guavaja (Guava) and Cucurbita pepo (Pumpkin) peels, and their antibacterial properties were evaluated against gram positive and negative bacterial isolates.

Methods: The effect of silver nanoparticles was tested against Staphylococcus aureus, Proteus mirabilis, and Gentamycin antibiotic sensitivity disks used as positive control, and the synthesised nanoparticles were analyzed using UV-visible spectroscopy, SEM, and FTIR. 

Results: The UV-visible spectra obtained at different peaks between 200nm and 700nm confirmed the presence of synthesized silver nanoparticles, while the FTIR revealed the presence of certain functional groups such as C=C stretch, C-H bonding, and Alcohol OH stretch, which represent bioactive compounds such as phenol, amine, and others. The capping and reducing properties of the produced silver nanoparticles are due to these biomolecules. The SEM indicated that synthesized nanoparticles had a spherical, hexagonal, rod, and triangular form. The antibacterial activities of the Nano-particles, such as MIC and MBC, demonstrated their efficiency against the tested bacterial isolate. Antibacterial activity of guava and pumpkin nanoparticles against Proteus mirabilis and Staphylococcus aureus were found to be effective.

Conclusion: The studies confirmed that aqueous peel extract of Psidium guavaja (Guava) and Cucurbita pepo (Pumpkin) are good sources for synthesis of silver nano-particles via green route, the biologically synthesized silver nano-particles were found to have effective broad spectrum of antimicrobial activity against Staphylococcus aureus and Proteus mirabilis.

Open Access Original Research Article

Aerobic Bioremediation of Brewery Effluent using Escherichia coli and Pseudomonas sp.

Udumma N. Onuoha, Prince O. Alaebo, George C. Njoku, Chibuzo V. Alisigwe

Asian Journal of Biotechnology and Genetic Engineering, Page 30-37

Effluent from Guinness Nig. Plc was obtained and inoculated with two aerobic organisms, and physicochemical analysis was carried out to evaluate the intrinsic degradative capabilities of the organisms based on the parameters to determine which organism has a better degradative potential for the effluent. This study used two bacterial species, Escherichia coli and Pseudomonas sp. The study was divided into two setups for each microorganism, and the third was set up as a consortium of the two. The study showed a reduction in biological oxygen demand (BOD) and a simultaneous reduction in the inorganic nutrient content of the effluent, such as phosphate, nitrate and sulphate, which were believed to be utilized for the growth of their biomass. This study confirms the potentials of the test organisms to mineralize brewery effluent in the presence of oxygen which is an environmental friendly and cost effective approach to effluent management.

Open Access Original Research Article

Bioremediation of Paper Mill Effluent using Bacillus subtilis and Escherichia coli

Udumma, N. Onuoha, Prince, O. Alaebo, George, C. Njoku

Asian Journal of Biotechnology and Genetic Engineering, Page 38-44

Effluent from onward paper mill limited Nigeria was collected and analyzed. Bacillus subtilis, Escherichia coli and mixed cultures of both organisms were used to bioremediate the effluent collected. The setups were inoculated with Bacillus subtilis, Escherichia coli and mixed cultures of these two organisms, respectively. Setup of E was inoculated and used as a control. Physicochemical and microbiological analyses were carried out for 12weeks to check the effectiveness of the organisms in carrying out the bioremediation process. The nitrate, phosphate and sulphate levels showed a reduction throughout this experiment. The pH ranged from 6.4-7.6. The BOD levels decreased in all setups, indicating microbial activities from 120mg /L - 92 mg /L in setup A. The mean population density of all the microorganisms for culture development also increased. It increased from 2.3x103 - 3.5x103 for Bacillus subtilis. This shows microbial growth and multiplication. Also, the dissolved oxygen level increased from 3.8mg /L - 4.7mg /L in setup D. The experiment indicates that the inoculated organisms carried out a certain degree of bioremediation.

Open Access Original Research Article

Physico-Chemical Analysis and Aerobic Bioremediation of Paint Effluent Using Pseudomonas aeruginosa and Bacillus subtilis

Udumma, N. Onuoha, Prince, O. Alaebo

Asian Journal of Biotechnology and Genetic Engineering, Page 45-52

Bioremediation uses biological techniques to reduce the harmful effects of pollutants in   the environment, including wastewater. It is a handy tool for various applications in environmental protection. In developing strategies for bioremediation of paint effluent, untreated paint effluent from Dulux Plc was inoculated with two aerobic microorganisms, Pseudomonas aeruginosa and Bacillus subtilis. Microbiological and physicochemical analysis was carried out for five weeks upon inoculation of effluent with Pseudomonas aeruginosa P, Bacillus subtilis B, in separate setups, effluent sample inoculated with both organisms M, to observe their synergy and  effluent sample without inoculation, served as a control sample to compare the abilities of the  native effluent microflora with that of the introduced microorganisms. The cultures of microorganisms were observed in nutrient broth until the exponential phase before their inoculation into the effluent sample. The bacterial cultures of Pseudomonas aeruginosa, Bacillus subtilis  and consortium contained 4.2 x 108cfu/ml, 3.8 x 109cfu/ml and 5.2 x 109cfu/ml, respectively,   when inoculated into the experimental setups P, B and M, in the experimental samples,  BOD and all the inorganic nutrient sources tested decreased rapidly with a proportional increase  in the population densities. This trend was firm for PO43- and NO3, which eventually became  limiting in the experimental and control samples. Inoculating microorganisms with the addition of appropriate inorganic nutrients may be a suitable method for rapid bioremediation of paint effluent.

Open Access Review Article

Biochemical and Molecular Insights into Abiotic Stress Tolerance in Plants

Rao Saad Rehman, Syed Ali Zafar, Mujahid Ali, Asad Nadeem Pasha, Hassan Bashir, Muhammad Awais Ashraf, Muhammad Usman Yaqoob, Mubashar Hussain

Asian Journal of Biotechnology and Genetic Engineering, Page 1-19

Plants cannot move, so they must endure abiotic stresses such as drought, salinity and extreme temperatures. These stressors greatly limit the distribution of plants, alter their growth and development, and reduce crop productivity. Recent progress in our understanding of the molecular mechanisms underlying the responses of plants to abiotic stresses emphasizes their multilevel nature; multiple processes are involved, including sensing, signaling, transcription, transcript processing, translation and post-translational protein modifications. This improved knowledge can be used to boost crop productivity and agricultural sustainability through genetic, chemical and microbial approaches.