Aims: The research was done to study the partial purification and characterization of thermostable alkaline protease from Lactobacillus brevis. Methodology and Results: The enzyme was purified in a two-step procedure involving ammonium sulphate precipitation and Sephadex G-150 gel permeation chromatography. The protease was purified 8.04 fold with a yield of approximately 30% after purification with Sephadex G-150 column. It has a relative molecular weight of 33.2 kDa and optimally active at a temperature of 60 oC and pH 9.0. The maximum velocity Vmax and Michaelis constant Km of the protease produced during the hydrolysis of casein were 66.66 U/mg protein and 3.33 mg/ml. It was strongly activated by Ca2+ and ethylene diamine tetra acetic acid (EDTA), mildly inhibited by Na+, K+, Mg2+ and Fe2+ and strongly inhibited by Cu2+ and Hg2+. The ability of the enzyme to improve the cleansing power of various detergents was also studied. Conclusion, significance and impact of study: The findings in this study suggest that the protease is a suitable candidate for detergent formulation and biotechnological applications.

The present study was carried out to evaluate the antimicrobial activity of the crude methanolic extracts of Memecylon malabaricum Clarke. (leaves), Cochlospermum religiosum Linn. (leaves and flowers) and Andrographis serpyllifolia Vahl. (leaves) using the standard disc diffusion assay against eight strains of bacterial species, viz., Staphylococcus aureus, Salmonella typhi, Enterobacter aerogenes, Pseudomonas aeruginosa, Xanthomonas oryzae pv. oryzae, Xanthomonas axonopodis pv. malvacearum, Bacillus cereus and Micrococcus sp. The extracts of the plants at a concentration of 1.25 mg/disc showed minimum to moderate activity against both Gram positive and Gram negative bacteria indicating a broad spectrum activity. A preliminary phytochemical screening was conducted on the selected plant extracts using standard qualitative procedures that revealed the presence of several secondary metabolites. The extracts failed to show antioxidant activity by reducing power assay. The result indicates the potential usefulness of these plants especially Memecylon malabaricum and Cochlospermum religiosum, in treating microbial infections in humans and plants and justifies the need for further investigations and characterization of the bioactive compounds present in the methanolic extracts of the plants.

Aims: A new methanogenic strain, named GFJ07, was isolated from a pond of mountain forests in Guangxi, China. Cells grown in liquid culture tended to form aggregates with pseudosarcina-like or irregular shape. Methodology and Results: The optimum temperature, pH and NaCl concentration were 35 ℃, 7.0 and 0.5%, respectively. The isolate used methanol, trimethylamine, acetate and H2-CO2 as substrates. Analysis of the 16S rDNA sequences revealed strain GFJ07 showed the highest sequence similarity of 99.9% to Methanosarcina mazei. Conclusion, significance and impact of study: The cells were Gram positive and nonmotile. Most of single cell grew as a sausage-like clinder about 0.5 μm in diameter and 1.0 μm in length.

Aims: Traditional Chinese medicine (TCM) has been used for relief and treatment of ailments dating back thousands of years and continues to the present day, with rapidly increasing interest in evidence-based evaluation of its efficacy. Studies of TCM plants have demonstrated that several have antimicrobial properties but few have explored their anti-quorum sensing potential. Quorum sensing (QS), also known as bacterial cell-to-cell communication, is used by a number of opportunistic pathogenic bacteria in the regulation of virulence expression. Compounds that interfere with QS signals and attenuate bacterial virulence without killing them may offer an alternative therapeutic solution with less pressure of antibiotic resistance developing. This study screened TCM plants for anti-quorum sensing properties and antimicrobial activities. Methodology and Results: Twenty TCM plants commonly used in South-East Asia were screened for QS inhibitors using two biomonitor strains, Chromobacterium violaceum CV026 and Pseudomonas aeruginosa PAO1. Ten of these selected TCM plant (50%) were found to have QS inhibitory properties: Angelica sinensis (Umbelliferae), Cnidium monnieri (Umbelliferae), Astragalus membranaceus (Leguminosae), Crataegus cuneata (Rosaceae), Dioscorea nipponica (Dioscoreaceae), Lilium brownii (Liliaceae), Aloe barbadensis (Liliaceae), Magnolia officinalis (Magnoliaceae), Ephedra sinica (Ephedraceae) and Panax pseudoginseng (Araliaceae). Of these, six (30%) also showed varying antimicrobial activity against C. violaceum and P. aeruginosa. Conclusion, significance and impact of study: The results suggest that traditional Chinese medicinal plants could be a prospective source to explore for useful compounds in the fight against bacterial infections.

Aims: Infections due to metallo-β-lactamase (MBL) producing Gram negative rods are a cause of high mortality and morbidity. Early detection by an economical and accurate method may improve patient outcome. This study was aimed to evaluate the diagnostic accuracy of combined disc method for MBL detection by comparing it with MBL-Etest. Methodology and Results: This cross-sectional, validation study was carried out in the Department of Microbiology, Army Medical College, National University of Sciences and Technology, Rawalpindi, over a period of six months. A total of 52 non-duplicate Gram-negative rods isolated from the routine clinical specimens and found resistant to meropenem/imipenem on Kirby Bauer Disc Diffusion method were subjected to two tests for metallo-β-lactamase detection. One was combined Disc test using imipenem with Ethylene Diamine Tetraacetic Acid (EDTA), where a strain showing an increase in zone of inhibition of combined disc of ≥ 7 mm as compared to imipenem alone, was considered as MBL producer and the other one was MBL-Etest for which results were interpreted as per manufacturer’s guidelines. Combined disc method for MBL detection was found to have a sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 97.5%, 100%, 100%, 92% and 98%. Conclusion, Significance and Impact of study: Combined disc method is an economical and reliable method for metallo-β-lactamase detection which can be used routinely in any laboratory.

Aim: Isolation, dark field detection and microscopic agglutination test (MAT) are considered ―gold standard‖ tests for diagnosis of Leptospirosis. Several PCR assays are reported but very few have been evaluated for detection of Leptospirosis. Therefore, this study was undertaken. This study aims to design and standardize polymerase chain reaction (PCR) -based DNA sequencing technique for the detection of pathogenic Leptospira from peripheral blood of patients clinically diagnosed with septicemia. Methodology and Results: Two hundred and seven (207) blood samples from patients were diagnosed with septicemia which includes 100 bacterial (other than Leptospira) culture positive and 107 bacterial culture negative samples were studied. Primers for Nested PCR targeting LipL32 gene of Leptospira interrogans were designed and the specificity of primers was tested against serum samples positive/negative by either MAT or dark field microscopy. PCR amplified products were further confirmed by DNA sequencing. The standardized nPCR was sensitive and specific to Leptospira interrogans. Twenty-one (21%) out of 100 culture positive blood samples, three (2.8%) out of 107 culture negative samples showed nPCR positivity and were confirmed as Leptospira interrogans by DNA sequencing (p<0.001). A sensitive nPCR specific to Leptospira interrogans was developed. Conclusion, significance and impact of study: The p value (<0.001) signifies that Leptospira is commonly associated with other bacteria circulating in blood indicating that a decreased immune status is created primarily by a bacterium with enhanced possibility of development of Leptospiral infection probably be of an endogenous origin.

Aim: This present investigation was conducted to determine the capability of fungi isolated from soil samples collected from two automobile workshopsto bioremediate Bonnylight crude oil. Methodology and Results: The fungi present on the soil samples collected from two automobile workshops in Akure, Nigeria were investigated using standard microbiological techniques. These fungal isolates were screened for the ability to degrade Bonnylight crude oil. The bioremediation of Bonnylight crude oil was observed spectrophotometrically using the broth culture (non- harvested cells) and harvested cells of the fungi isolated from the contaminated sites for a period of 20 days on minimal salt broth. Mycotypha microspora, Penicllium italicum, Botryris cinerea, Gliocladium deliquescence, Verticillium albo–atrum and Aspergillus niger were isolated from the contaminated site while Neurospora crassa, A. parasiticus, A. niger and Gonatobotryum apiculatum were isolated from uncontaminated sites. All the fungal isolates were capable of active degradation in varying degrees. Conclusion: The study shows that all the isolated fungi were capable of degrading the crude oil in varying degrees. The active crude oil utilizing fungi in this study were Aspergillus niger (both harvested and non harvested cells) and Gliocladium deliquescence (non harvested cells) and Penicillium italicum (harvested cells). Aspergillus niger has best degrading ability than other fungi in non harvested and harvested cell condition. However, non harvested cells recorded the higher degradative ability than harvested cells. Therefore, non harvested cells can be employed in bioremediation of Bonnylight crude oil. Significance and Impact of Study: The fungi isolated from automobile mechanic workshops contaminated soil can be exploited in the bioremediation of Bonny Light crude oil.

Aim: Auxin, a phytohormone secreted by plant growth-promoting rhizobacteria is one of the direct mechanisms vital for plant growth promotion. A laboratory experiment was conducted to observe the effect of IAA-producing and non-IAA-producing diazotroph Bacillus cereus strains on early growth of shallot (Allium ascalonicum) and mustard (Brassica juncea) plants. Methodology and Results: Treatments evaluated were as follows: Control = uninoculated, no inoculation, UPMLH1 = IAA-producing B. cereus UPMLH1, and UPMLH24 = non-IAA-producing B. cereus UPMLH24. Inoculation with IAA-producing B. cereus UPMLH1 significantly increased shallot adventitious roots (root number and length) and shoot growth (19 to 54% increment). Inoculation of non-IAA-producing B. cereus UPMLH24 did not significantly improve growth of adventitious roots of shallot as compared to uninoculated control, except its shoot (up to 40% increase). However, primary roots and shoot growth of mustard plants significantly increased through inoculation with IAA-producing and non-IAA-producing strains (14 to 73% increment). Conclusion, Significance and Impact of Study: The results indicated that exogenous IAA secreted by B. cereus UPMLH1 might have play an important role in inducing roots of shallot bulbs and it may have a variable promotional effect depending on plant species.

Aim: Nanotechnology is an increasingly growing field with its current application in Science and Technology for the purpose of manufacture of novel materials at the nanoscale level. Silver-Titania nanoparticles (AgTiO2-NPs) have been known to have inhibitory and bactericidal effects. Methodology and Results: In the present study, stable silver-titania nanoparticles coated metallic blocks were prepared for testing their efficacy against selected bacterial pathogens like Escherichia coli and Staphylococcus aureus. In the experimental part, the bacterial pathogens were inoculated on silver-titania nanoparticle coated blocks and the treatment was carried out in „0‟ time and „24‟ h interval and were enumerated. Conclusion, significance and impact of study:The results were compared with the control (uncoated metallic blocks) and analyzed by using Japanese Industrial Standard (JIS Z2801:2000) method. From this study, it was concluded that silver-titania nanoparticles has inhibitory effect on bacterial pathogen tested.

Aims: The antimicrobial activities of the leaf extract of Moringa oleifera on certain enteropathogenic and orthopaedics’ wounds bacteria and fungi were investigated. Its phytochemical constituents and nutritional potentials were as well assessed. Methodology and results: The antimicrobial activities of the leaf extracts were evaluated using paper disc diffusion method. All the leaf extracts showed little inhibitory effect on the enteropathogens, whereas aqueous and methanolic extracts showed appreciable inhibitory effects on the orthopaedic’s wounds bacteria at 30mg/ml. Ethanolic extract did not show any zone of growth inhibition on the wound bacteria. All the fungal organisms except Aspergillus flavus were resistant to both aqueous and methanolic extracts of the leaf, meanwhile Ethanolic extract showed appreciable inhibitory effect on Tricophyton mentagrophyte, Pullarium sp, Aspergilus flavus and Penicillium sp. Minimum inhibitory concentration was 20mg/ml on all the enteropathogens and ranged from 3.75 to 30