International Journal of Applied Sciences and Biotechnology

Journal Information
EISSN : 2091-2609
Published by: Nepal Journals Online (JOL) (10.3126)
Total articles ≅ 659
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Narayan Kunwar, Manoj Kc, Rashika Shrestha, Sushil Chaudhary, Anima Shrestha, Bibek Rana Chhetri
International Journal of Applied Sciences and Biotechnology, Volume 10, pp 164-170;

With rapid population growth, unmanaged urbanization, and industrialization, the holy river Bagmati, has become one of the most contaminated water sources in Kathmandu, Nepal. As a result, the river has lost its capacity for self-purification and became ideal habitat for many pathogenic microorganisms such as E. coli, Salmonella, Vibrio, etc. The study aimed to perform the antibiogram profile of Salmonella species. According to the findings, Salmonella was identified in excessively polluted areas with sewage. Out of total 55 samples, 34.45% were Salmonella positive among which, 10.5% were found to be S. Typhi and S. Paratyphi, and the remaining 79% were found to be other S. enterica serovar. S. enterica serovar was detected in abundance from site B1. Site B2 yielded Salmonella Typhi and Salmonella Paratyphi isolates. Furthermore, Salmonella Paratyphi was isolated from Site B3. The water samples from Site B6 were proven to be Salmonella-free. Antibiotic Susceptibility Test was performed for the positive samples and all the serovars were found sensitive to Amikacin whereas least sensitive to Ampicillin i.e., 86.67%, 100%, and 50% resistant in case of other S. enterica serovar, S. Typhi and S. Paratyphi respectively. All the Salmonella species isolates were sensitive to Ciprofloxacin, Streptomycin, Ofloxacin, and Nitrofurantoin but 100 % resistant to Ampicillin. However, there is not a single data reported as Multi-Drug Resistant Salmonella species in this study. The study emphasized the use of effective treatments against the disease and addresses the health danger to people, animals, and many other living species living nearby the river.
Karun Adhikari, Ashis Rai
International Journal of Applied Sciences and Biotechnology, Volume 10, pp 182-189;

Blister blight is one of the most significant foliar fungal diseases of tea plant caused by Exobasidium vexans. An invitro experimentation on efficacy of biofungicides and chemical fungicides was carried out at Agriculture Research Station, Pakhribas from November 2020 to January 2021 to evaluate and analyze effectivity of two Trichoderma spp and five commonly used chemical fungicides against Blister Blight pathogen. Isolates of Trichoderma viride and Trichoderma harzianum were tested against E. vexans using dual culture technique. Five Chemical fungicides namely Copper oxychloride 50WP, Hexaconazole 5% EC, Metalaxyl 8% WP+ Mancozeb 64% WP, Carbendazim 50% WP, Carboxin 37.5% WS + Thiram 37.5% WS were tested at four different concentrations viz. 50 ppm, 100 ppm, 200 ppm and 500 ppm using poisoned food technique. The experiment was carried out in completely randomized design with three replications for each treatment. Both Trichoderma viride and Trichoderma harzianum demonstrated significant effect on mycelial growth reduction of E. vexans. Trichoderma viride and Trichoderma harzianum exhibited 70.87% and 66.98% inhibition in growth of E. vexans respectively. Similarly, Hexaconazole, Carbendazim, Carboxin + Thiram provided complete (100%) inhibition on pathogen growth regardless of concentration. Least inhibition (36%) on pathogen growth was recorded at 50 ppm of Copper Oxychloride. All chemical fungicides provided significant difference on reducing growth of pathogen in comparison to control at all concentration. It is recommended that Trichoderma spp be taken as a priority regarding its environmental benefit and furthermore if application of chemical fungicides is necessitated, rationalized use be done at lower dose and with appropriate timing.
Upama Chapagain, Sujan Bhandari, Yogendra Man Shrestha, Sagar Bista, Januka Dahal
International Journal of Applied Sciences and Biotechnology, Volume 10, pp 171-181;

A study was conducted to determine the effect of pruning practices and different fertilizer combinations on Bhaktapur local variety of cucumber under protected structure in Panchthar, Nepal during February to June 2021. The experiment was laid out in two factorial Randomized Complete Block Design with three replications. Treatments used were two pruning practices (no pruning and 3G cutting) and four fertilizer doses (no fertilizer (control), 30 Mt/ha FYM+ 100% RDF (140:60:100 kg of NPK), 9.4 Mt/ha Vermicompost+ 100% RDF of NPK and 4.3 Mt/ha Poultry manure+ 100% RDF of NPK). Although 3G cutting practice increased the days required for 50 % flowering, it significantly decreased the male: female flowers ratio (1.69) compared to no pruning (4.38). Similarly, number of fruits per plant, individual fruit weight, fruit diameter and average fruit yield (95.21 Mt/ha) were maximum in 3G cutting. In terms of fertilizers, time requirement for 50% male flowering remained unaffected, however, plants treated with fertilizers 30 Mt/ha FYM+ 100% RDF of NPK showed significantly least days required for 50% female flowering, lowest male: female flowers ratio (2.41), maximum number of fruits per plant, maximum average individual fruit weight and highest average yield (105.78 Mt/ha) which are statistically at par with results of 9.4 Mt/ha vermicompost+ 100% RDF of NPK and 4.3 Mt/ha poultry manure+ 100% RDF of NPK for these parameters. The results concluded that combined application of organic manures and inorganic fertilizers in recommended dose with 3G pruning practices is best for growth and yield of cucumber.
Bibek Rana Chhetri, Dipika Acharya, Arjun Gautam, Nasala Bajracharya, Anuj Shrestha, Smriti Khadka
International Journal of Applied Sciences and Biotechnology, Volume 10, pp 140-148;

Lignocellulosic biomasses (LCB), second-generation biofuels are used as an alternative means to cope with the burning issues of depleting fossil fuels like petroleum products with the added advantage of renewability, lower emission, and lesser pollution. For the increment in the production of LCB biofuels, microbial pre-treatment processes are conducted which accelerates the degradation of organic polymers like lignin and hemicellulose with the activity of potential microorganisms. To increase the efficiency of degradation of hemicellulose, hemicellulolytic fungi including Trichoderma and Aspergillus and other bacteria produce multi-enzymatic complexes like cellulosomes. Similarly, organisms like Tinea versicolor, Dichomitus squalens, Phlebia floridensis, Daedalea flavida, and Phlebia radiata contain lignin-degrading auxiliary enzymes and lignin modifying enzymes like laccase and heme-containing peroxidase which aid in delignification process. Several factors are associated with pre-treatment processes like the type of strain, inoculum load, pH, temperature, fatty acids, C/N ratio, time, aeration, grindability, surface area, particle size, and supplements added. To enhance the pretreatment method, the combination of microbial with physical, chemical, and mechanical methods is suggested which leads to a synergistic effect and better yield of the final product. Overall, biofuels should be more employed and this review aims to bring light to the microbial pre-treatment approaches which can aid in the efficient production of biofuels that can directly contribute to environmental sustainability.
Anuska Sharma, Bijaya Adhikari, Mahesh Shrestha, Dipesh Raj Pant, Bindra Devi Shakya, Achut Ram Pradhananga, Sudarshana Shakya, Pawan Raj Shakya
International Journal of Applied Sciences and Biotechnology, Volume 10, pp 149-163;

The present study aimed to determine Cd, Cr, Cu, Pb, and Zn concentrations using flame atomic absorption spectrophotometer (FAAS) in five vegetables viz., Coriander (Coriandrum sativum), Mustard (Brassica campestris), Radish (Raphanus sativus), Spinach (Spinacea oleracea) and Chinese spinach (Amaranthus dubius), and their growing soils in three agricultural sites (Manohara, Bode, and Nagadesh) of Madhyapur Thimi, Bhaktapur district and to assess health risks using USEPA deterministic approaches. The average concentrations of HMs in soils were 0.85, 30.65, 40.06, 47.42, and 129.55 mg/kg for Cd, Cr, Cu, Pb, and Zn respectively, exceeding the normal soil quality standards except Cr. Similarly, the average concentrations of HMs in vegetables were 0.42, 6.63, 22.33, 1.34, and 77.16 mg/kg for Cd, Cr, Cu, Pb, and Zn respectively exceeding joint FAO/WHO standards except for Cu. The I-geo values revealed a class of unpolluted to moderately polluted levels for the agricultural soils indicating the 1st degree of soil pollution. Among the vegetables, Chinese spinach measured considerably high transfer factor (TF) for Cd (0.79), Cr (0.34), Cu (0.76), Pb (0.04), and Zn (0.89) indicating health concerns to the consumers. The hazard index (HI) for these HMs was found less than the acceptable limit (1.0) indicating no non-carcinogenic risk to adults through vegetable consumption. However, the lifetime carcinogenic risk (LCR) parameter indicated low to high cancer risk for Cd, Cr, and Pb. Among the vegetables, Chinese spinach estimated the highest LCR values for the HMs suggesting regular monitoring of HMs in soil and vegetable on account of their toxic effects.
Ronika Thapa, Anjal Nainabasti, Ashish Lamsal, Santoshi Malla, Yushika Subedi, Shirish Ghimire
International Journal of Applied Sciences and Biotechnology, Volume 10, pp 75-83;

Pesticides are applied to protect crops from insects, weeds, and bacterial or fungal diseases during the growth. There would be a 78 percent loss of fruit output, a 54 percent loss of vegetable production, and a 32 percent loss of cereal production if pesticides were not used. When pesticides are applied to a target plant, they have the potential to enter the environment where they can affect non target organisms. Concerns have also been raised about pesticide currently uses and its impact on the environment with the possibility for hazardous or carcinogenic residues. This review paper provides basic information about the general types of pesticide in use and the role of pesticides in agriculture with its impact in environmental components. Int. J. Appl. Sci. Biotechnol. Vol 10(2): 75-83.
Aakash Adhikari, Bigyan G.C.
International Journal of Applied Sciences and Biotechnology, Volume 10, pp 134-139;

In view of suitable climatic condition in mid hill of Nepal, sweet orange is emerging as a new enterprise for farmers, for which the government of Nepal has also given priority to this crop. In the light of these facts, a case study was conducted in Pyuthan municipality of Pyuthan district to identify the problems related to sweet orange in Pyuthan municipality. All of the farmers had their own land for Sweet orange production. Majority of the respondents (80%) had the annual income below NRs. 20000. Farmers were able to increase their higher education, household expenses, health and savings from Sweet orange production. Transportation, irrigation, citrus greening disorder and green stinky bug were major problem in Sweet orange production in study area. Study suggested that concerned stakeholders should focus their program on quality seedling production, input use, and human resource management, and scientific orchard management, capacity development of farmers, insect pest management, scientific value chain management and post-harvest loss reduction for overall development of sweet orange industry in Pyuthan district. Int. J. Appl. Sci. Biotechnol. Vol 10(2): 134-139.
Sanjay Kumar Rai, Sanjay Kumar Singh, Arun Kumar, Apoorva
International Journal of Applied Sciences and Biotechnology, Volume 10, pp 84-92;

An experiment was carried out using virus-resistant papaya variety Pune Selection-3 to study the effect of different cultivation methods for enhanced production and input use efficiency at Horticultural Research Farm, RAU, Pusa during the year 2016-2019. The outcomes of raised bed cultivation (a), drip irrigation (b), fertigation (c), polyethylene mulching (d) along with micronutrient spray (e) were analyzed using different combinations of these parameters as treatments for growth, yield-related parameters, and fruit quality. Nutrient use efficiency was also assessed by examining various interactive components such as soil nutrient content, nutrient acquisition with nutrient content in the leaves, the efficiency of nutrient utilization informs of the biomass produced, fruit yield, and fruit nutritional quality. The plant height was maximum in T1 (155 cm) which was significantly higher than the plant of control treatment. The flowering time was found to be reduced in all treatments. However, total soluble sugar was higher in T3. Overall, when the B:C ratio was compared, the treatment (T1) showed a higher value along with a 2.38-fold fruit yield/plant and 0.89-fold increase in fruit yield per hectare. The nutritional quality of fruits enhanced in T1 treated plants having a 1.78-fold increment in flavonoid content, and 1.2-fold more lycopene. The phenolic content was also 1.8-fold higher than the control (T5). The result obtained in the present study demonstrates that with the implementation of a suitable fertigation system in papaya cultivation we can obtain papaya growth, fruit yield per plant, and fruit quality by targeting enhancement in cost: benefit ratio. Int. J. Appl. Sci. Biotechnol. Vol 10(2): 84-92.
Bibek Rana Chhetri, Preksha Silwal, Pooja Jyapu, Yumika Maharjan, Trishana Lamsal,
International Journal of Applied Sciences and Biotechnology, Volume 10, pp 104-111;

Organic waste can be enzymatically degraded by microbes. In this study, the Bacillus species were isolated from soil and identified as Bacillus subtilis, Bacillus licheniformis, Bacillus macquariensis, Bacillus brevis, and Bacillus circulans which were optimized considering pH (5, 7, 9) and temperature (37°C, 45°C, 55°C) for the maximum production of amylase, gelatinase, lipase, and cellulase, principally for the degradation of organic waste. The maximum production of amylase was found at 37°C with pH 7 and 9, gelatinase and lipase at 37°C with pH 5,7,9 by almost all identified species. Similarly, the production of cellulase was shown by Bacillus licheniformis only at 45°C, pH 5. The degradation was confirmed by the analysis of the solid content of degraded waste. The maximum degradation of starch and lipid-containing waste was shown by Bacillus macquariensis whereas Bacillus circulans were able to degrade gelatin-containing waste effectively. Bacillus species showed a synergistic effect in biodegradation. Bacillus subtilis and Bacillus licheniformis used in ratios 1:1 and 1:2 were found to be effective degraders of lipid and starch-containing waste respectively. Bacillus macquariensis, Bacillus brevis, and Bacillus circulans used in ratio 1:1:1 showed effective degradation of gelatin-containing waste. The degradation of the organic waste by multi-enzyme producer Bacillus species can be the most effective and eco-friendly method and their optimization for enzyme production can be beneficial for commercial enzyme production as well as for biotechnological applications. Int. J. Appl. Sci. Biotechnol. Vol 10(2): 104-111.
International Journal of Applied Sciences and Biotechnology, Volume 10, pp 124-133;

Earthworms are of ecological and economic significance and are directly related wit human health through biogeochemical cycle. Such a valuable faunal group needs immediate intensified taxonomic treatment in Nepal for their sustainable use, efficient commercial production and biodiversity conservation. Systematic random sampling was used for site selection and hand sorting method was used for sample collection from the field. Collected specimen were photographed in field and preserved in ethanol for lab study with tagging. In total, study reported eight species belonging to two families Lumbricidae and Megascolecidae. External morphological features helped on identification and taxonomic key preparation. Among two sites 6 species were common and abundantly recorded from almost habitats whereas, 1/1 species were different in each site with uncommon reporting from harsh environment. Cultivated crop land with litter and compost was known to be more diverse in species richness than other habitats. Detail taxonomic study and distribution mapping is an essential for Earthworms in Nepal to complete the global database and national soil engineer documentation for organic and healthy environment. Int. J. Appl. Sci. Biotechnol. Vol 10(2): 124-133.
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