Thesis & Dissertations

Permanent URI for this community

https://hdl.handle.net/20.500.14540/12

Browse

Now showing 1 - 15 of 15

Application of Bacteriophage in Nosocomial infection control, A new concept to disinfect Hospital environment
(Department of Biotechnology, 2021) Upreti, Himani
Introduction: Health care associated infections (HAIs) are one of the important public health problems which might result in significant rise in mortality and morbidity, predominantly in immune compromised patients of Intensive Care Unit (ICU). A study showed that in the Asian region, risks of HAIs have been estimated to be 2-20 times higher than in developed countries up to 25% of hospitalized patients having acquired infection (Ling et al., 2015) and also a report shows that in United States, roughly 9.2 out of every 100 patients acquire a nosocomial infection, according to Healthline and among them also some HAIs is quite serious and potentially life-threatening. The common bacteria causing nosocomial infections include Pseudomonas aeruginosa, klebsiella pneumonia, Acinetobacter baumanii, Enterococci etc. (Khan, Baig, & Mehboob, 2017). Therefore, disinfectants like alcohols, hypochlorite, hydrogen peroxide, amyl phenol, glutaraldehyde etc. are widely used in hospital to kill these organisms which cause NAs but sometimes these chemical disinfectants might be hazardous, irritants and toxic to us and environment. Among many alternatives, bacteriophage mediated bio-control of the pathogenic bacteria is considering as one of the best options. Our objective of the study is to isolate, identify the pathogenic bacteria from the hospital environment and evaluate the efficacy of newly isolated lytic bacteriophage to minimize the bacterial load on hospital fomites. Methodology: The study time period of this research was 6 months and, in this study, we isolated phage against Pseudomonas aeruginosa bacteria collected from ICU of Teku hospital. Then most potent phage was characterized morphologically and Physiochemically. Burst size was obtained from one step growth curve. Intraspecific and interspecific host range was assessed by spot assay. During this research work, we used sterile fomite cloth pieces and marble tile as they are most potent sources were bacteria reside. Firstly, we contaminate the fomites and tiles with Pseudomonas aeruginosa bacteria then after we used Pseudomonas aeruginosa phage to decontaminate those cloths and tile. Result: Altogether 16 bacterial strain, 4 Pseudomonas aeruginosa and 12 Staphylococcus aureus were confirmed by Gram staining and Biochemical test and among them 2 Pseudomonas aeruginosa strains and 5 Staphylococcus aureus strains were found to be Carbapenem resistance and Multi Drug Resistant (MDR) respectively. Total six bacteriophages against Pseudomonas aeruginosa were isolated from different sewage samples. And one of the most potent phage P4 was characterized morphologically and physiochemically. Burst size of the phage was found to be 28 virions per bacterium. Protein profiling was done by SDS-PAGE where protein band between 20-250Kda were found and Phage P4 belongs to order Caudovirales and family Siphoviridae. Similarly, Phage was found to tolerate temperature of 70°C for 20 minutes, pH 3-12, exhibiting multiple host range as well. Decontamination assay was done on the sterile fabric cloth which showed that the P4 phage having MOI value 1 showed higher rate of decontamination with log reduction of 1 and p-value (0.002) i.e., significant. Further Comparison was done between P4 phage and normal disinfectant Phenol where we found that single phage has more disinfectant rate than phenol. xi Similarly, time period up to which bacteriophage can show their effectivity as disinfectant was also done and it showed highest level of effectivity up to 6 hours at MOI 1 with the CFU/ml log reduction of 1. Conclusion: The result from the present thesis reveals several characteristics of the bacteriophage (P4), for instance, effective lytic capability, multiple host range, and stability in wide range of pH and temperature. Higher rate of decontamination with the log reduction of 1 CFU/ml and p-value (0.002) was showed by P4 phage having MOI value of 1. While doing comparison single phage have more disinfectant rate than normal disinfectant & P4 phage can show its highest level of effectivity up to 6 hrs at MOI 1. Keywords: Nosocomial Infection, disinfectant, Pseudomonas aeruginosa, bacteriophage, decontamination
Computational drug discovery against Hepatitis B Virus Core Protein
(Department of Biotechnology, 2023) Itani, Ramesh Raj
Hepatitis B virus infection has been a major global health concern today.The present available drugs are not able to cure the hepatitis B completely.So the scientific community in world are in search of new drugs that can fulfill the void of existing non performing drugs. The problem of the low efficacy of present drugs and development of new resistant mutant virus needs to be solved immediately for the advancement in the cure of hepatitis B infected patients. Traditional drug discovery process is time and money consuming process so computer aided drug designing can be a good alternative for drug discovery process. In this study ligand library from different databases like asinex, zinc15, selleckchem are used.Ligands from these databases are screened for ADMET properties in order to ensure the drugability characters. The selected ligands are subjected to molecular docking purpose with the target protein i.e. hepatitis B core protein under the PDB name 5T2P .The ligands that have higher binding affinity with target protein was selected for further screening .hMAT1A screening was done with selected ligands to ensure that selected lead molecules donot harm liver.The lead compounds was selected after hMAT1A screening and subjected to density function theory to study its chemical properties computationally. Benzofuranonesshows the higher binding affinity with target protein and selected as lead molecules after hMAT1A screening. Keywords: ADMET, CADD, Molecular Docking, Lead compound, FDA, hMAT1A
Frequency of BCR-ABL1 transcripts in chronic Myeloid Leukemia
(Department of Biotechnology, 2021) Raut, Rojit
FREQUENCY OF BCR-ABL1 TRANSCRIPTS IN CHRONIC MYELOID LEUKEMIA. Background: Chronic myeloid Leukemia (CML) is among the largest group of leukemia cases in Nepal. Underlying pathology in CML is the translocation between ABL1 gene and BCR gene. The breakpoint in the BCR and ABL1 gene may vary leading to the formation of various types of fusion transcripts viz. p210, p190, p230 and other rare variants. Literatures suggest p210 is the most common transcript type seen in CML. Eventhough rare, the variants such as p190 and p230 have also been reported. However, studies are lacking to see the transcript type of CML patients in Nepal. Molecular diagnosis of CML is mostly done in the referral laboratories in India. In this study, we tried to analyse the frequency of different BCR-ABL1 transcripts (p210, p190, p230) in Nepalese CML patients in a laboratory within Nepal. In addition, the response of different transcripts towards drugs being used was also analysed via protein-ligamd interaction. A total of 45 samples were studied using real-time and conventional method and virtual screening approaches were explored to study drug interactions. Methodology: During the study period, a total of 45 cases of suspected CML patients were included. Total RNA was extracted and reverse transcribed to cDNA using standard protocols. qPCR was performed with primers and probes targeting p210, p190 and p230 transcripts. The protein-ligand study was carried out using docking tools. All the results were statistically analysed. Results: Almost all the cases, 44/45 cases (97.7%) were positive for p210 transcript only. CML was found to be more common in males with M:F ratio of 2.44 : 1. The disease was more prevalent in Kshetri community. The disease was more common in middle aged population with median age of 43 years at diagnosis. Transcript type variation made no impact to drug affinity in CML patients. Conclusion: p210 transcript is the most prevalent transcript type in our study. Hence p210 must be targeted in the suspected cases of CML. Transcript type made no effect in drug use however larger studies may be informative regarding the frequency of other rare variants in Nepalese patients and developing effective treatments. Keywords: BCR-ABL1, Chronic Myeloid Leukemia, Nepalese population, Real-time PCR, Transcripts, Docking.
In Silico Drug Repurposing Against Salmonella typhimurium LT2 Dam Protein
(Department of Biotechnology, 2023) Maharjan, Suja
The increasing prevalence of Multidrug-Resistant (MDR) pathogens has resulted in the failure of current antibiotics to effectively treat these infections. Computer Aided Drug Discovery (CADD) has become a crucial tool in the drug discovery process recently. It has been demonstrated to be a successful method for screening lead compounds against target proteins within a short amount of time and with optimal resources. In the present study, a computational approach, CADD tools were employed to identify novel drug candidates against Salmonella enterica serovar Typhimurium LT2, targeting its essential gene, Dam. Virtual screening of various ligand libraries was conducted. From the initial library consisting of 21,000 compounds from natural products, 10,342 compounds from indole derivatives, 1,685 compounds from Kinase Inbibitors and 3,118 compounds from Nucleoside mimetics after ADME/Tox and druglikeness filters were narrowed down the number of compounds to 205 Natural Products, 462 Indole Derivatives, 6449 Kinase Inhibitors, and 654 Nucleoside Mimetics. The final screening from molecular docking and binding energy resulted in the identification of four lead compounds, Antineoplaston A10 and Cardamonin from natural products, 5-cyclopentaneamido-1-ethyl-N-(2methoxyethyl)-1H-indole-2-carboxamide from Indole Derivatives, 2 [[anilino(oxo)methyl]amino]-4,5-dimethoxybenzoic acid from Kinase Inhibitors and 3-[[[4-[2-(3,5-Dimethylpyrazol-1-yl)ethoxy]phenyl]methylamino]methyl]-1-(6methylpyrimidin-4-yl)pyrrolidin-3-ol from Nucleoside Mimetics were identified as potential leads. These compounds showed higher binding affinity with the target protein and lower binding efficiency for human hMAT1A protein compared to the reference compound S-Adenosyl methionine (SAM) and S-adenosyl homocysteine (SAH). The stability and strength of protein-ligand binding were observed through protein-ligand interactions, Density Functional Theory (DFT), analysis of frontier molecular orbitals and vibrational spectra. The results suggest that these compounds may be potential candidates for further exploration against other MDR pathogens prioritized by the World Health Organization (WHO). Keywords: CADD, Multidrug-Resistant, Dam, essential gene, lead compounds
Integration of Electrochemical cell for Enhancement of Biogas production from cattle manure and molecular characterization of isolated microflora
(Department of Biotechnology, 2021) Prajapati, Bikram
Nepal is a developing country where most of the population is still living in rural areas. A continuous supply of cooking gas as Liquid Petroleum Gas is difficult and expensive. So biogas is a good alternative for them. Biogas production is affected by several factors; temperature is an important factor to be considered during anaerobic digestion (AD) for effective degradation of organic waste. Though most of the rural areas’ of Nepal have assembled biogas plant, due to the climatic variation, during winter season, production of biogas is less. Enhancement of biogas production can be done by various methods. Among them integration of microbial electrochemical cell (MEC) system in existing AD is a new and innovative technique where a small voltage of electricity supplied to reduce CO2 produced in digester to methane with help of methanogens as a biocatalyst. AD using cow dung is cheap and clean method of production of biogas which help to reduce serious environmental and health problems. During this work, integration of microbial electrochemical cell (MEC) system in conventional anaerobic digester showed reduction percentage was 2.7% and 8% greater in 1 L and 5 L digester respectively in MEC compared to conventional control setup while reduction of soluble reducing sugar was 33% and 9% greater in 1 L and 5 L digester at 15°C compared to control setup. At room temperature (23-29°C), reduction percentage of COD was about 11% and 18% higher in comparison to controlled digester. Likewise, reduction percentage of soluble reducing sugar was 32% higher in 1L and 19% higher in 5 L digester compared to the control digester. Biogas production was enhanced by about 28% compared to control setup even at temperature of 15°C in both 1 L and 5 L digester. Similarly, enhancement of biogas in 1 L digester and 5 L digester was 35.18±0.52% and 41.17% respectively at room temperature. Despite of enhancement, the reaction of microbial electrochemical cell was done successfully for short period of time which is not enough for complete digestion of cow dung. Hence, further study on the MEC for elongated digestion of organic waste and assembly of fed batch system is necessary. We analyze the change in different parameters for already existing 6000 L biogas plant. There was very negligible change in COD, soluble reducing sugar as there was a provision of continuous feeding of substrate every day. For the identification of microorganism, among six isolates 14IN and 18IN showed significant level of cellulase production while doing hallo zone test with congo red. PCR product of 16s rRNA of while sequenceing showed the microorganisms 14IN and 18IN were Bacillus licheniformis and Bacillus aerius respectively. Keywords: Biogas, microbial electrochemical cell, anaerobic digestion, chemical oxygen demand.
Mining envelope domain III of Dengue virus for recombinant tetravalent DNA vaccine candidate from Nepalese samples
(Department of Biotechnology, 2021) Thapa, Machchhendra
Dengue is caused by a single stranded positive sense RNA flavivirus, Dengue virus (DENV), which is transmitted predominantly by female mosquito vectors Aedes aegypti, Aedes albopictus. It leads to disease in human from mild dengue fever (DF) to a life threatening, severe Dengue Hemorrhagic Fever (DHF) or Dengue Shock Syndrome (DSS). All dengue viruses (serotypes 1-4) can infect human. Once infected the patients develops immunity against all serotype for limited time period. Risk of secondary infection increases as immunity against other serotype decreases. There is higher risk of development of severe dengue during secondary infection due to Antibody Dependent Enhancement (ADE). ADE results in enhanced virus entry and greater virus replication which lead to severe dengue. It also one of the hurdles in the vaccine development and acceptance. Early diagnosis can help patients to get necessary treatment in time and effective preventive measures should be taken to reduce the dengue cases and mortality due to dengue fever. So there is an urgent need for a dengue vaccine that induces long-lasting, simultaneous protection to all four serotypes of dengue while avoiding the immune enhancement of viral infection. For the dengue vaccine development the Envelope region of dengue virus has been widely studied. Envelope region contains three domains, among Domains I, II and III of envelope region, Domain III remain choice of interest due to its reduced risk of Antibody Dependent Enhancement (ADE) in dengue infection. Envelope Domain III (EDIII) of the dengue envelope protein has been implicated in receptor binding, and is also the target of specific neutralizing antibodies thus EDIII has emerged as a promising region for a vaccine candidate. Considering EDIII as candidate instead of whole envelope might address the solution to existing problems of dengue vaccine in use and it might eliminate the risk of ADE. In the present study, we aim to identify all four serotypes and amplify serotype specific EDIII region. Further we aim to fuse EDIII region of different dengue virus serotypes and construct recombinant bivalent construct and tetravalent construct. Then we aim to recombine the construct into a mammalian expression vector to make a single recombinant tetravalent ED III dengue vaccine construct for its subsequent use as a novel vaccine candidate because it is exposed to the surface and thus becomes the primary target for antibody-mediated neutralization. Keywords: Dengue, Envelope Domain III, Antibody Dependent Enhancement, Recombinant DNA, Vaccine
Molecular and Probiotic Characterization of Lactobacillus SPP. Isolated from Traditionally Prepared Curd (DAHI) at Different GEO- Climatic Conditions of Nepal
(Department of Biotechnology, 2016) Koirala, Ranjan
Available with Full text
Molecular characterization of Leishmania spp. causing cutaneous Leishmaniasis in Nepal
(Department of Biotechnology, 2021) Rai, Tinmaya
Leishmaniasis is one of the leading vector borne disease to cause death world-wide. It is caused by more than 20 Leishmania species in 98 countries in five continents. The disease is categorized as one of the most “neglected tropical diseases'' and has a strong and complex association with poverty. Nepal, was formerly endemic for the visceral type where fewer cases of cutaneous leishmaniasis has been seen. Due to lack of facilities at all medical centers, diagnosing the disease is challenging. The main concern right now to determine the types of Leishmania spp. that are currently prevalent in Nepal and identifying whether or not the agent that causes visceral form is also responsible for cutaneous form. Patients with cutaneous lesions were sampled for parasitological diagnosis using direct examination (DE), kinetoplast DNA (kDNA) nested PCR (CSB1X/CSB2X and 13Z/LiR primers). Further, the kDNA positive samples were amplified for the ITS-1 region. The amplified ITS-1 region were subjected to Restriction Fragment Length Polymorphism (RFLP) using enzyme HaeIII. For the validation of the RFLP result Sequencing was performed. The data were statistically analyzed using graph pad prism. Only 22 (55%) were found to be positive for kDNA Nested PCR observed bands were 720bp, 600bp for Leishmania donovani complex and Leishmania major respectively and 12 (30%) on ITS-1 PCR. Following, ITS1 PCR-RFLP genotyping of ITS-1 with restriction enzyme HaeIII, results in two distinct patterns that clearly distinguished L. donovani (50,75,180 bp) from L. major (140, 210bp). The RFLP finding was then validated by sequencing the amplified ITS1 PCR products. This study finds that the parasite L. donovani which causes visceral form of the disease is also the causative agent for cutaneous form. Two species L. donovani and L. major are circulating species causing Cutaneous Leishmaniasis. As the CL is in increasing trend in Nepal. PCR based diagnostic facilities might help to prevent misdiagnose the disease. Molecular screening can be done by ITS1 PCR-RFLP followed by sequencing. Keywords: Cutaneous leishmaniasis, HaeIII, kinetoplast DNA, nested PCR, RFLP, Sequencing.
Molecular Detection of Sars-Cov-2 RNA in Nasopharyngeal/Oropharyngeal Swab of Patient Without RNA Extraction
(Department of Biotechnology, 2022) Karna, Suruchi
RT-PCR is the gold standard method used till date for covid19 detection. Owing to the limited supply of SARS-CoV-2 RNA extraction kits in different health care facilities of Nepal, it results in enormous pressure to optimize reagent use, thereby affecting the overall diagnostic quality. This proposed research aimed to detect SARS-CoV-2 RNA from NPS through direct RT-qPCR technique omitting entire RNA extraction process. For this, 184 clinical NPS samples were obtained from Covid19 suspected patients who visited the Kirtipur Municipality-TU Biotech Corona Laboratory, and all subsequent steps were carried out there. These corresponding sample was subjected to RNA extraction followed by RT-qPCR as well as heat inactivated- RT-qPCR for validation. Eventually, their Ct values were compared wherein, the impact of heating temperatures and sample volume on assay sensitivity was also studied. The overall efficacy of these techniques was comparatively analyzed based on their Ct values. Heating NPS samples (n=184) for 20 min at 70 °C yielded a sensitivity, specificity, and accuracy of 93.3%, 96.7%, and 91.3% respectively. According to our paired T-test analysis, the mean Ct values of the N1 and RNase P genes were statistically significant at 95% CI (p<0.001), whereas the N2 genes were not (p>0.001). The results thus obtained was also compared with that of conventional RT-qPCR technique. Thus, a strong agreement using Cohen’s Kappa (κ=0.803) was found between two methods indicating reliability of heat inactivation assay. Therefore, direct RT-PCR might be a useful method for quickly identifying COVID19 suspects. This research offers a quick fix for the RNA extraction supply crunch. Furthermore, this emerging concept could even drastically lower costs and accelerate assay TAT by omitting the RNA extraction step.
Nutritional Status of Cultivated Mushrooms of Kathmandu Valley
(Department of Biotechnology, 2016) Devkota, Dilli Raman
This investigation provides the proximate screening of nutrients and minerals present in the four cultivated mushroom species sold in the markets of Kathmandu valley. The cultivation practices include all the exotic mushroom species introduced from India, Japan and China. They are Lentinula edodes, Pleurotus ostreatus, Agaricus bisporus and Pleurotus djamor. All these mushrooms are cultivated in the corners of Kathmandu valley and brought to the vegetable markets such as Asan, Kalimati, Balkhu and Lagankhel for sale. The result of the analysis indicated that the mushrooms are good sources of Crude Protein (23%to 46.3%), Carbohydrate (28% to 50%), Fat (2.4% to 4.2%), Fiber (11.9% to 17.9%), Ash (6.3% to 18.3%) and moisture (79% to 93.3%). The nutrient contentvaries widely among the mushroom species. The result showed that the mushrooms are good source of nutritionally important minerals including Phosphorus (100.7mg to 837mg), Calcium (11.82mg to 165mg) and Iron (6.07mg to 52mg) per 100g on dry weight basis. GC- MS result analysis suggested that mushroom samples are free of pesticides. Based on the result of this study, it is suggested that these mushroom species are nutritionally good without any human hazard.
Physicochemical and genomic characterization of bacteriophage against Pseudomonas aerouginosa causing urinary tract infection; An apprach to biofilm reduction.
(Department of Biotechnology, 2022) Timalsina, Sudip
Introduction: Pseudomonas aeruginosa is resistance to most of the antibiotics. This makes treatment of Pseudomonas aeruginosa difficult. The problem is further compounded by its ability to form biofilm. The aim of this study was to isolate lytic phage against antibiotic resistant Pseudomonas aeruginosa and to use it in the reduction of Pseudomonas aeruginosa biofilm. Methodology: Bacteriophage isolation was done by Double Layer Agar Assay method. Burst size and latent period of the phage was determined by one step growth curve experiment. Phage stability was also analyzed against different temperature and pH range. Phage cocktail was used to disrupt biofilm. The synergistic effect of phage and antibiotic in reducing biofilm was also analyzed. Effect of various external factors in phage stability was examined. Whole genome sequencing of phage DNA was done. Result: Lytic bacteriophage against Pseudomonas aeruginosa was isolated. The latent period of the phage TU_pse1B was 30 minute and burst size was 27 virion per bacterium. The optimum temperature for the phage TU_pse1B was 37:C and optimum pH was 9. Three distinct bands of phage proteins of size 35, 40 and 100KDa were observed after performing SDS PAGE. Phage DNA size was determined to be larger than 10 Kb from agarose gel electrophoresis. Whole genome sequencing of phage revealed its size to be 43,428 nucleotides (43 Kb) in length and the GC content of 62.16%. Calcium ion increased the phage adsorption. Phage showed stability against SDS and osmotic shock whereas it was susceptible to ethanol, acetone and CTAB. Phage TU_pse1B reduced the biofilm by 60.99% whereas Phage TU_pse1Bi reduced the biofilm by 60.37%. Synergism of phage and antibiotic was observed in reducing biofilm. Phage plus antibiotic reduced biofilm by further 26.67% than phage alone. Conclusion: Phage TU_pse1B showed good stability to various physiochemical factors as well as it was efficient in reducing Pseudomonas aeruginosa biofilm. So, this phage can be a good candidate for controlling antibiotic resistant Pseudomonas aeruginosa. Keywords: Antibiotic resistance, Biofilm, SDS, Phage cocktail, AST, Burst size.
Production of Bioethanol by Electrochemical Redox Coupled with Microbial Cells Using Lignocellulosic Biomass
(Department of Biotechnology, 2020) Joshi, Jarina
Bioethanol, blended with gasoline (petrol), is used as liquid transportation fuel worldwide. Local production and use of bioethanol supports local economies, decreases a country’s carbon footprint and promotes self-sufficiency. The latter is especially important for bio-resource rich, land-locked countries such as Nepal that are seeking alternative transportation fuels and technologies to produce them. Bioethanol is a renewable resource that is dominantly produced from either sucrose or starchy biomass. As Nepal is rich in agricultural sector, use of residual lignocellulosic biomass from plants can be a better alternative for bioethanol production. The lignocellulosic biomass composition of plants differ depending on the locality and seasonal changes. We have evaluated the suitability of four different sources of lignocellulosic biomass, viz., Ipomoea carnea, Phragmites karka, Saccharum spontaneum and Zea mays cobs for obtaining reducing sugar which can be used for bioethanol production in Nepal. S. spontaneum was found to be the best among the four as an economic source of lignocellulosic biomass since it has better degradation capabilities, high caorific value and relatively high total reducing sugar (TRS) content (612.2±11.5 mg·g vii -1 biomass). Hot water pretreatment of S. spontaneum biomass at 100 o C for 2 h followed by hydrochloric acid hydrolysis (TRS = 330.4±20.5 mg·g -1 biomass) were found to be the best for release of fermentable sugars. The variations in characteristics of lignocellulosic biomass before and after pretreatment with hot water at 100 o C for 2 h were investigated by using differential thermo gravimetric curve (DTG), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy methods. The XRD and FTIR analysis showed that pretreatment reduced the amorphous nature of cellulose and increased crystalline characteristics. The content of glucose (untreated: 246.7±4.0 and pretreated: 235.1±5.0 mg·g -1 biomass) and xylose (untreated: 86.6±3.9 and pretreated: 62.5±3.0 mg·g -1 biomass) determined in untreated and pretreated (hot water at 100 o C for 2 h) biomass suggested that while the cellulose loss during pretreatment was minimal, hemicellulose content was lost significantly. The conventional method to produce ethanol is via microbial fermentation and it comes with limitations. We have demonstrated the feasibility of using a bio-electrochemical system to improve ethanol production by yeast. In this system, externally supplied 4V was used to drive the chemical reactions to generate higher levels of ethanol in the yeast cultures. In the present study, we have identified two highly efficient ethanol producing yeast strains, viz., Saccharomyces cerevisiae (CDBT2) and Wickerhamomyces anomalous (CDBT7) out of twelve isolates and used them in a bioelectrochemical cell to enhance ethanol production. CDBT2 and CDBT7 were cultured in anodic and cathodic compartments with fine platinum coated platinum anode and neutral red coated graphite-felt cathode, ethanol production was drastically enhanced by 52.8±0.44% in average. The above experiments were repeated using lignocellulosic biomass hydrolysates (Saccharum spontaneum by pretreating with hot water for 2 h at 100 o C followed by hydrolysis with 0.5M HCl) as substrate resulted better enhancement in ethanol production (61.8±0.12%). Use of cellulose acetate in place of nafion membrane as anodic and cathodic partition better enhanced ethanol production by 6.30±0.22%. The enhancement in expression of alcohol dehydrogenase and pyruvate decarboxylase was seen when voltage was supplied. The results concluded that CDBT2 and CDBT7 yeast strains produced ethanol efficiently from both glucose and lignocellulosic biomass hydrolysate. The ethanol production was enhanced in electrochemical cell in the presence of low level of external voltage. Ethanol production was further enhanced with the better involvement of electron transport systems, when neutral red was deposited on cathode and platinum nanoparticles were coated on the platinum anode and cellulose acetate as partition membrane. This can be an optimal method for commercial ethanol production from biomass hydrolysate after up scaling.
Production of sake from local variety of rice using isolated mold from local starter culture, Murcha
(Department of Biotechnology, 2021) Chaudhary, Sawan Kumar
Rice wine is alcoholic beverage made by simultaneous saccharification and fermentation by using mold and yeast. Rice (Oryza sativa) is staple food for half the world population. In Nepal, local starter culture (Murcha) has been used for starter culture for production of cereal based alcoholic beverage. The quality of alcoholic beverage always varies due to lack of process standardization in term of culture and process. There for an attempt was made to isolate and screen mold and yeast from the murcha collected from different districts of Nepal and used in production of rice wine. The performance of mold was tested for saccharifying capacity. Seven molds isolates from murcha were tested for saccharification by halo zone on starch media, microscopic observation, liquefication and DNS test. All the isolated molds exhibit better growth in YPD media and showed positive result of starch hydrolysis. Among all the isolates the mold isolated from murcha (Rajbiraj) showed better saccharifying capacity than other isolates. It showed 36% saccharifyimg capacity, higher than that of other isolates. The mold which have higher saccharifying capacity is used for production of rice wine. In the rice wine total volume of alcohol was found to be 8%, pH was 3.42, succinic acid was 3.9 mg/L and ester was 11.1 mg/L. The lab prepared rice wine was compared with a commercial rice wine, and found comparable with respect to alcohol content, pH, total acidity and ester content. The essential oils was determined by using GC/MS. Key words: Murcha, saccharification, fermentation, GC/MS, rice wine
Screening of Novel Genes Involved in Bio-Film Mediated Resistance to Antibiotics in MDR Pseudomonas aeruginosa
(Department of Biotechnology, 2022) Manandhar, Padma Ratna
Available with full text
Validation of rapid antigen test as diagnostic tool for detection of SARS-CoV- 2AS compared with real time RT-PCR
(Department of Biotechnology, 2022) Gautam, Suman
Introduction: Testing of samples from suspected SARS-COV-2 individuals with rtRT-PCR result leads to delayed in detection of infection. Early recognition of SARS-CoV-2 infection is crucial for both the improvement of turnaround time and limiting the spread of the virus in the Community. Huge number of people affected in pandemic, it is important to use a test that give faster results and can be used on large number of sample. Rapid Antigen Test fulfills both the criteria. AIM: The aim of our study was to evaluate the diagnostic performance of two antigen rapid diagnostic kits (RAT) to diagnose SARS-CoV-2 infection in comparison to rtRT-PCR. So, we evaluated two commercially available antigen kit. Methods: A laboratory based descriptive Crosssectional study was performed in Trishuli Hospital Nuwakot from January 2021 to December 2021. Result: Out of 1295, 472 tested positive in RAT test while 715 tested positive for SARS-CoV-2 RNA genome via rtRT-PCR. Specificity was 98.2% for Panbio and 96.9% for SD Biosensor. Sensitivity for sample with CT ≤ 20 was 93.5% and 94.2% and for sample with CT ≤ 25 was 93.7% and 93.5% and for CT ≤ 30 was 82.9% and 81.4% with p < 0.001 in case of Panbio and SD Biosensor respectively. The overall diagnostic performance of RAT showed 64.2% sensitivity and 97.8% specificity. Agreement with PCR was excellent for high viral load sample CT<20: Panbio, kappa=0.921; SD Biosensor, Kappa= 0.912 and CT value <25: Panbio, Kappa=0.926; SD Biosensor, Kappa=0.906. Significant difference (p value <0.0001) was observed between RAT+ and RAT- results when compared to CT value obtained from the rtRT-PCR. The diagnostic accuracy for RAT was 79.2% with kappa=0.59 showing moderate agreement and empirical benchmark was set with Youden’s Index 0.597 to be administered as diagnostic purposed. Conclusion: The RAT performed well as a POCT test for early diagnosis of COVID-19 in primary healthcare centers. More crucially finding from our study is that RTPCR proven SARS-CoV-2 infection and negative by RAT are not likely to be infectious. Keywords: SARS-CoV-2, rtRT-PCR, RAT, Sensitivity, Specificity

Browse

Browsing Thesis & Dissertations by TU Institute "Central Department of Biotechnology"

Results Per Page

Sort Options