Asian Journal of Microbiology and Biotechnology
Not a member yet
167 research outputs found
Sort by
The Assessment of the Microbial and Hygienic Quality of Leafy Vegetables Along with Associated Microbials among Vegetables Purchased from Different Markets in Guyana
No full textFruits and vegetables are important to human health because they provide nutritional benefits, they are a good source of vitamins and minerals and help to improve the immune system of individuals. It was advised by the Food and Agriculture Organization of Guyana that individuals should consume more fruits and vegetables to boost their immune systems during the Coronavirus pandemic. Due to the increase in consumption of fruits and vegetables, there can also be an increase in cases of food-borne diseases, as evident from studies done in countries such as, the United States, Malaysia, and India. The objectives of this research was to identify the presence of microorganisms on leafy vegetables, Lactuca sativa (lettuce), Brassica oleracea (cabbage), and Amaranthus viridis (callaloo), that were purchased from local markets and to determine if washing with tap water only, will significantly decrease the concentration of microorganisms on the vegetables by performing microbial assessments.
It was found that the most common microorganisms present on the leafy vegetables were pathogenic bacteria such as Neisseria spp., Pseudomonas aeruginosa, Paracoccus marcusii, Pseudomonas fluorescens, Bordetella pertussis, and Klebsiella pneumonia. The results of a Wilcoxon signed-rank test (p value = 1) revealed that washing with tap water alone did not significantly decrease the quantity of microorganisms present on the leafy vegetables (avg: 3.305x10-2 CFU/ml). Therefore, it is recommended that other hygienic methods such as washing with salt, lemon juice, or vinegar should be utilized in order to significantly reduce the concentration of the microorganisms present on the leafy vegetables.  
Oncogenesis Induced by Polyomavirus (BKV)
No full textPolyomavirus BK (BKV) or human Polyomavirus is an icosahedral, non-enveloped virus classified under the Polyomaviridae family. The oncogenic properties of BKV belong to both an early domain and late domains. BKV encodes important Tag proteins such as LTAg and STAg “Tumour antigen; Tag. They succeeded in altering and stimulating infected cells to uncontrolled proliferation experimentally in both culture cell and animal models. This study aims to summarize the important oncogenic pathway that BKV used to initiate tumor. Both BKV proteins LTAg and STAg interfere with many cellular pathways/proteins such as retinoblastoma proteins, PP2A, P53, MAP kinases pathway, tumor suppressor proteins, telomerase, endothelial growth factor, leading to uncontrol of cell proliferation and apoptosis. This study concluded that stimulation of cell growth and secretion of extra endothelial growth factor in the absence of antiapoptotic proteins increases BKV proteins to mediate cancer development. 
Lactic Acid Bacteria as Probiotics: Current Status and Future Prospects
No full textFrom the last decade, the use of probiotics for human health has received greater recognition as scientific authentication and validation keep on increasing in the properties, functionality, and beneficial effects of probiotics Lactobacillus on human health. In the group of lactic acid bacteria the Lactobacillus is the predominately strains and most utilized for the production of fermented dairy products, sourdough, vegetable foods, meat or used as probiotics. Lactobacilli are considered especially as beneficial bacteria, because they are recommendable microbiota of the gastrointestinal tract, urinary, and genital systems without causing any disease. The gastrointestinal tract absorb the probiotics and stimulates the immune system and activate the regulatory T cells that further release the IL-10. On the other hand, bacteriocins a kind of ribosomal produced antimicrobial peptides synthesized by different bacteria and stable to heat. Many researchers purified and identified bacteriocins for utilization in food industry to extend food preservation time, manage pathogenic diseases and cancer therapy, and maintain human health. In the future Bacteriocins possibly become a potential drug candidate to treat multiple drugs resistance pathogens instead of antibiotics. The European Food and Safety Authority deny the health claims of probiotics because of unavailability of molecular mechanisms and their modes of action, irreproducibility of trials, as well as strong individual responses of the hosts, and strain-specificity. Similarly, information on the dose effects are still lacking and need explored further so that probiotic become potential substitute of the antibiotics for the cure of the diseases. Various techniques have been developed for construction of genomic modifications in Lactobacillus, including food-grade ones which results in strains labelled as non-GMO. These are still very useful for the multitude Lactic acid bacteria applications wherever GMOs are not acceptable. Nowadays consumers are aware of gut health and concept of preventative health care, therefore growing demand for probiotics increasing day by day. Therefore, the present review focused on the developments and applications of the Lactobacillus and bacteriocins producing lactobacillus
Isolation and Characterization of Extracellular Chitinase Produced by Chitinolytic Bacteria Isolated from Soil Samples
No full textChitin is one of the most common biopolymers found in both marine and terrestrial habitats. Chitinase enzyme has gained popularity due to its diverse biotechnological applications, particularly in agriculture for the biocontrol of phytopathogenic fungi and harmful insects. In this work bacteria producing chitinase enzyme were isolated from soil and water samples. Three bacterial isolates C2, C3, and C4 were found to be Gram-negative coccobacilli while bacterial isolate C9 was found to be Gram-positive cocci. The optimum pH and temperature for all the isolates were studied. The effect of pH, temperature, substrate variation, and incubation period on enzyme activity was studied. The activity of the chitinase enzyme for all the bacterial isolates increased with an increase in temperature up to 37°C. However, a further rise in reaction temperature caused a loss of chitinase activity. Michaelis-Menten plot and Line weaver Burk plot were constructed to calculate the Km and Vmax values. Partial Purification of the chitinase enzyme was carried out and the enzyme activity, protein content, specific activity, and purification fold were estimated. It was observed that the enzyme activity of the crude sample was less than the fractionated sample. The highest enzyme activity was found to be at a 40% fraction. Of the four isolates, C2 was the best in its enzyme activity. The future prospect is the production of chitinases at an industrial scale for various biotechnological applications. Chitinase-producing isolates have the ability to produce chitinase between temperatures 22ºC and 40ºC which is the field temperature for the cultivation of most the crop, so it may be applicable to field conditions against plant pathogenic fungi which is the major problem for agricultural food production. The management of seafood waste businesses may potentially benefit from the usage of this enzyme
CONCORDANCE OF METHYLENE BLUE REDUCTION AND MICROBIOLOGICAL TECHNIQUES IN THE ANALYSIS OF RAW AND PROCESSED MILK QUALITY: A COMPARATIVE STUDY
No full textRaw milk is a milk that has not undergone pasteurization for an effective pathogen elimination, thus having a reduced shelf life due to microbial activities. Microorganisms such as bacteria can affect the quality of diary products, hence the need to assess the microbial quality of natural cow milk, pasteurized milk and processed tin-milk which are consumed on daily basis in Nigeria, Africa and the world at large. In this study, raw (unpasteurized) and processed milk samples from two locations (Bogobiri and Watt market) in Calabar municipal were analyzed using methylene blue reduction test (MBRT), total heterotrophic bacterial count (THBC) and total coliform count (TCC). The total Heterotrophic bacterial count ranged from too numerous to count (TNTC) to 3.86 x 106 colony forming unit (CFU)/milliliter (ml) in samples MA (Unpasteurized/Raw cow milk) and MB (Pasteurized cow milk) respectively. There was no fungal growth in five of the samples except MA that had a fungal count that was TNTC. The highest TCC was obtained from sample MA, with a value of 2.96 x 106 CFU/mL while sample MD had the lowest count of one colony. The total microbial count from sample MA was extremely high and above the standard signifying that it is unfit for human consumption. The MBRT result revealed that MD (Processed liquid tin-milk) and MC (Processed liquid tin-milk) gave no methylene blue reduction (excellent quality) while MB (Pasteurized cow milk), ME (Processed liquid tin-milk) and MF (Processed liquid tin-milk) were of fair quality. However, MA gave a poor quality based on the MBR time of between 30 m to 2 h corroborating with the high value of its THBC which was above the standard. Milk being a vital protein source and an excellent medium for microbial growth should be thoroughly treated by sterilization in a bottle as the study revealed that the milk microbial load can be greatly reduced by pasteurization, with sterilization in bottle having a greater bactericidal effect than pasteurization
ANTIBACTERIAL ACTIVITY OF Aframonum melegueta (ALLIGATOR PEPPER) AND Xylopia aethiopica (AFRICAN PEPPER) AGAINST MULTI-DRUG RESISTANT E.coli AND Klebsiella spp. ISOLATED FROM URINE SAMPLES
No full textThis study was carried out to assess the antibacterial activity of Aframomum melegueta and Xylopia aethiopica against multi-drug resistant E.coli and Klebsiella spps isolates from urine samples. A total of 100 urine samples were collected from Ikwo local Government Health Center, Ebonyi state, Nigeria. Isolation and identification of bacteria isolates were carried out using standard microbiological methods. Kirby-Bauer disc diffusion method was used in the antibiotics susceptibility test, agar diffusion method was employed for determination of zone of inhibition of the two extracts. Twenty eight (28) isolates were confirmed to be E.coli while 20 isolates were confirmed Klebsiella spp. Seven E.coli isolates and 5 Klebsiella isolates were Multi-Drug Resistant (MDR). The isolates showed resistance to most of the antibiotics used and were susceptible to only Imipenem (IPM). The two extracts showed mild antibacterial activity on the MDR isolates. Xylopia aethiopica extract showed little zones of inhibition at concentration of 6.25mg/ml while there was no zone of inhibition recorded for Aframomum melegueta extract at concentrations of 6.25mg/ml and 12.5mg/ml. The wider zones of inhibition recorded was at the highest concentration of the two extracts at 50mg/ml
PROXIMATE ANALYSIS AND MINERAL COMPOSITION OF THE PEELS OF THREE VARIETIES OF SWEET CASSAVA
No full textOne of the most significant tubers grown in Africa, cassava provides around one-third of the daily calories consumed. It has several nutritional advantages and is often ingested after peeling, washing, boiling, or drying. The objective of this study was to ascertain the mineral and proximate content of cassava peels from 3 sweet varieties. The analysis was carried out using accepted methods. The outcome revealed that TMS/98/0581 has 2.84% protein content. TME/98/419 with 4.33% and TMS/98/30572 with 2.41%. The carbohydrate content showed that TMS/98/0581 has the lowest parameter with 72.20% while TMS/98/30572 has the highest with 75.82% followed by TME/98/419 with 75.20%. Also, the DM (Dry Matter) of TME/98/419 has the highest yielding with 87.51% followed by TMS/98/30572 with 86.95% while TMS/98/0581 has the lowest DM of 85.97%. The fat content of TME/98/419 yielded highest parameter of 1.09% followed by TMS/98/0581 with 0.46% and the least was TMS/98/30572 with 0.40%. The fiber content of TMS/98/0581 cultivar produced the least content with 5.44% followed by TMS/98/30572 with 6.13% and the highest been TME/98/419 with 6.62%. The peel further contained certain amount of minerals. The peel of cultivar TME/98/419 contained 19.81mg/100g which is the highest while TMS/98/30572 has the lowest with 13.74mg/100g followed by TMS/98/0581 16.23mg/100g. Zinc content of TME /98/419 yielded the highest parameter of 6.72mg/100g followed by TMS/98/30572 for 5.65mg/100g and the least is TMS/98/0581 with 5.36mg/100g. Furthermore, the magnesium content of TMS/98/0581 had the highest value of 14.81mg/100g followed by TME/98/419 with 14.40mg/100g and the least TMS/98/30572 with 12.80mg/100g. The result therefore showed that cassava peels could serve as supplementary source of essential nutrients for animal feeds with healthy benefits than its disposal
MAJOR VIRULENCE FACTORS AND PATHOGENICITY ISLANDS IN PATHOGENIC CLOSTRIDIUM SPECIES
No full textClostridia are obligately anaerobic, spore-forming bacilli that, at least in the early stages of growth, stain gramme positive. Clostridia produce greater toxins than any other bacterium genus, and pathogenic clostridia are typically diagnosed by their unique toxins. Clostridium spp. has been found to have more than 20 toxins and other extracellular proteins that contribute to virulence, such as spread factors and proteolytic enzymes. Botulinum and tetanus toxins are the most potent poisons ever discovered. Clostridium botulinum neurotoxins are the most potent acute toxins identified, and they are the cause of the neuroparalytic illness botulism. Such toxins work by inhibiting presynaptic nerve terminal neurotransmission in the peripheral and central nervous systems. Other clostridia toxins have different modes of action, such as tissue destruction, hemolysis, diarrhoea, or generating an overactive immunological response in the recipient. On non-integrative lysogenic bacteriophages or plasmids, the genes coding for numerous clostridial toxins are found. Protein secretory processes in Clostridia are poorly understood. It has remained a mystery as to how the tetanus toxin, which lacks a normal N-terminal signal peptide, is exported until today. Typical PAI are DNA segments that are found in pathogenic bacteria\u27s genomes but not in nonpathogenic strains of the same or similar species
SCREENING AND IDENTIFICATION OF GENETIC PURITY OF OKRA HYBRID [RANI] AND ITS PARENTAL LINES BASED ON MOLECULAR MARKERS
No full textThe present investigation was carried out to identify the genetic purity of okra hybrid and its parental line based on molecular markers. For the evaluation of genetic purity and varietal identification from collected Okra samples, molecular markers and polymerase chain reaction, as well as DNA fingerprinting approaches, were advocated. These samples were accumulated from field and nursery Adithya seeds Pvt. Ltd, Raipur (C.G) within the duration of study and research from January to July 2018. Genetic purity test over the conventional Grow-Out-Test (GOT) was achieved by using Random Amplified Polymorphic DNA (RAPD) and Inter-Simple Sequence Repeat (ISSR) primers for identifying and emphasizing of hybrid. Using 3 lines of Okra cultivars, we analysed the products of PCR with RAPD and ISSR primers and discussed the design for constructing their Genetic Purity. Towards this study 64 random primers were screened between okra hybrid (Rani) and its parental lines [male line (206) and female line (189)]. Out of 64 primers only one primer (ISSR-B17898) showed polymorphic banding pattern between hybrid and its parental lines which helped in the identification and confirmation of okra hybrid. Hence, concluded that Genetic purity test is necessary for seed certification of different categories in seed multiplication chain both from agronomic as well as breeding point of view and proved to be explicit technology for researchers
PRODUCTION AND CHARACTERIZATION OF BIODEGRADABLE FE ALLOY
No full textIn this study, biodegradable Fe-Zn alloys were fabricated by conventional powder metallurgy method for temporary implant applications. Magnesium, iron and zinc are the 3 main biodegradable metals. In general, biodegradation rate of the magnesium alloys is too high, while biodegradation rate of the zinc alloys is slow and zinc alloys are brittle. In addition, Zinc alloys show low strength and low plastic deformation. In general, biodegradation rate of the iron alloys is very slow. Biodegradable Fe-Zn alloys are promising for the temporary implant applications. In the present study, metal ion release amounts from the Fe-Zn alloy samples were lower than the toxic limit for the humans. Increasing Zn content from 0.5 to 12.0 weight % was decreased the elastic modulus of the alloys from 160 GPa to 125 GPa. Quantity of Zn and Fe ion release values were increased with the immersion time in SBF. Weight loss of the Fe-Zn alloys was increased with the immersion time. Increasing immersion time from 1 to 21 days increased the weight loss value from 0.4 to about 2.4 %. Increasing Zn content of the alloy raised the electrochemical corrosion rate of the alloy