Screening of Actinomycetes from Soil for Antibacterial Activity

Actinomycetes are Gram positive, free living saprophytes which are distributed in soil as one of the major populations and are primary source of antibiotics. This study was carried out with a quest to isolate actinomycetes from soil samples of different places and assess their antibacterial activity. Isolation of actinomycetes was carried out by serial dilution of soil sample followed by spread plate method. The antimicrobial extract was extracted using ethyl acetate. Assessment of antimicrobial activity was performed by using Agar cup plate assay against test organisms (Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, Salmonella typhi, Salmonella paratyphi, Bacillus subtilis, Staphylococcus aureus). Antibacterial activity was tested against Methicillin Sensitive Staphylococcus aureus and Methicillin Resistant Staphylococcus aureus in the isolates having effective inhibitory activity against Staphylococcus aureus. From 15 soil samples of 12 different locations, 121 actinomycetes isolates were isolated. Among them, 58 (47.9%) isolates were inhibitory against at least 1 test organism in primary screening, of which 22 isolates effective against more than 1 test organism was chosen for secondary screening. Out of them, 8 were inhibitory against 2 test organisms while 14 were inhibitory against 3 test organisms. Staphylococcus aureus was found to be the most susceptible test organism with its susceptibility against 12 actinomycetes isolates. Among 12 isolates effective against Staphylococcus aureus, 10 were found to have an inhibitory effect against Methicillin Susceptible Staphylococcus aureus while 6 were found to have inhibitory effect against Methicillin Resistant Staphylococcus aureus strain. The findings of this study highlight the inhibitory potential of actinomycetes and the need for further investigation for obtaining novel antimicrobial agents from actinomycetes from various unexplored areas

Screening of Potential Plant Growth Promoting Properties of Bacillus Species Isolated from Different Regions of Nepal

The deleterious effects of intensive use of chemical fertilizers and pesticides in agriculture has led to the substantial research efforts on finding the alternatives to these agrochemicals. This study was aimed to isolate Bacillus species from soil of different regions of Nepal and screen for their ability to promote plant growth directly or indirectly by testing their ability to produce plant growth hormone indole acetic acid, hydrogen cyanide, ammonia and protease as well as phosphate solubilization. Thirty nine Bacillus strains were isolated from 25 soil samples of different regions of Kathmandu and Chitwan districts of Nepal. These isolates were tested for plant growth promoting traits in vitro. Among the total isolates, about 48.7% were indole acetic acid producers, 38.4% of the isolates showed the ability to solubilize the phosphate, 71.8% were able to produce ammonia and all the isolates had the ability to produce hydrogen cyanide and protease. The isolated strains showed positive results to maximum PGPR traits and exhibited a potential to be used as alternatives to chemical fertilizers and pesticides and could be used as low-cost bio-based technology to promote plant growth in the agricultural sector

Analysis of microbiological quality and adulteration of raw milk samples from different areas of Kathmandu Valley

Milk is a highly nutritious product that is susceptible to degradation due to microbial activity. Maintaining milk quality is crucial and can be achieved by monitoring specific parameters. This helps preserve the nutritive value of milk, which is essential for proper growth and health. Adulteration and improper storage can diminish the nutritional quality of milk. Therefore, this study aimed to assess the microbial load and adulteration of milk samples collected from various regions of the Kathmandu Valley. Sixty raw milk samples were gathered from local dairies (45) and cow farms (15) between April 2019 and July 2019. These samples were evaluated for microbial quality (total plate count, total coliform count, Salmonella spp., Shigella spp., and Vibrio spp.) and adulterants (starch, table sugar, soda, soap, and hydrogen peroxide) following standard guidelines. Out of the total samples, 58.3% (35) exhibited coliform growth, while Shigella spp. and Vibrio spp. did not grow on any media. Among coliforms, Enterobacter spp. was the most prevalent at 33.3%, followed by Escherichia coli at 32%. Antibiotic susceptibility testing revealed that the highest proportion of bacteria was sensitive to Ciprofloxacin and Gentamycin, followed by Ceftazidime. Adulteration analysis indicated that 33.3% and 48.3% of samples were adulterated with sugar and soda, respectively. Starch and soap were not detected in any analyzed samples. The highest titratable acidity (0.16%) was observed in cow farms compared to dairy farms. The findings of this study suggest an urgent need for routine quality testing of milk samples available in the market to prevent the spread of milk-borne diseases and preserve the nutritive value of milk

Bridging the Gap between Academia and Practice: Project-Based Class for Prestressed Concrete Applications

Educational approaches in structural engineering have focused on classical methods for solving problems with manual calculations through assignments, quizzes, and exams. The use of computational software to apply the learned knowledge has been ignored for decades. This paper describes an educational approach to tackle the lack of applicable practical exercises in the structural engineering class “CE 506-Prestressed Concrete” at a university in the western United States during the spring of 2017. The class was designed to provide students with the theoretical concepts of prestressed concrete and the ability to interpret applicable design codes. In their project, students continued to build this knowledge by designing a prestressed bridge superstructure according to a unique state design manual. Students prepared a literature review of their selected state in the U.S.A. and used commercial software to perform an analysis and design of their bridge. Additionally, students were asked to backcheck their design using theoretical methods through manual calculations. By the end of the class, students presented their projects in a head-to-head presentation format, to contrast the differences between their designs in a competitive style. This paper summarizes the class structure, the outcome of the design project, and recommendations for future applications of computer technology in structural engineering education

Bridging the Gap between Academia and Practice: Project-Based Class for Prestressed Concrete Applications

Educational approaches in structural engineering have focused on classical methods for solving problems with manual calculations through assignments, quizzes, and exams. The use of computational software to apply the learned knowledge has been ignored for decades. This paper describes an educational approach to tackle the lack of applicable practical exercises in the structural engineering class “CE 506-Prestressed Concrete” at a university in the western United States during the spring of 2017. The class was designed to provide students with the theoretical concepts of prestressed concrete and the ability to interpret applicable design codes. In their project, students continued to build this knowledge by designing a prestressed bridge superstructure according to a unique state design manual. Students prepared a literature review of their selected state in the U.S.A. and used commercial software to perform an analysis and design of their bridge. Additionally, students were asked to backcheck their design using theoretical methods through manual calculations. By the end of the class, students presented their projects in a head-to-head presentation format, to contrast the differences between their designs in a competitive style. This paper summarizes the class structure, the outcome of the design project, and recommendations for future applications of computer technology in structural engineering education