Abyssinia Journal of Science and Technology https://journals.wu.edu.et/index.php/ajst <p><strong>Abyssinia Journal of Science and Technology (AJST)</strong> is newly established African scientific journal publishing from Wollo University, Ethiopia. It is an international, peer-reviewed and an open access scientific journal publishes two times per year. This journal publishes original research articles, short communications and occasionally reviews articles that generate the significant contribution in the field of science and technology. Its scope covers all aspects of Natural Sciences, Agricultural Sciences, Medical and Veterinary Sciences &amp; Engineering and Informatics.</p> <p>To qualify for publication, a manuscript must contribute to the understanding of science and technology by presenting either new and original research data as a full research article or in short communication format or review of a particular topic related to science and technology.</p> <p><strong>Date of Publishing: </strong>Every year first issue in <strong>JUNE </strong>and the second issue in<strong> DECEMBER</strong></p> Wollo University, Ethiopia en-US Abyssinia Journal of Science and Technology 2616-471X Isolation and Characterization of Rhizobacteria with Biocontrol activities against Faba bean (Vicia faba L.) Chocolate spot disease causing Botrytis fabae https://journals.wu.edu.et/index.php/ajst/article/view/429 <p>This study has aimed at isolating and characterizing rhizobacteria having biocontrol traits against chocolate spot (<em>Botrytis fabae </em>L.) that attacks faba bean. Accordingly, a total of 52 rhizobacterial isolates were recovered from rhizosphere of faba bean and screened for biocontrol activities against the test pathogen using dual culture method. Of these, only 50% of them showed inhibition against the pathogen. All the 26 isolates with antagonistic activities against <em>Botrytis fabae </em>were characterized using standard microbiological methods. The isolates inhibited the radial growth of the pathogen at an inhibition percentage ranging to 52.5- 85.8%. Among these isolates, 17(65.38%) of them were Gram negative. Regarding the isolates’ plant growth promoting properties, 26(100%), 23(88.5) and 21(80.8%) were positive for nitrogen fixation, phosphate solubilisation and indole acetic acid production, respectively. The minimum and maximum phosphate solubilisation indexes of the isolates were 2.3 and 4.1 cm, respectively. The hydrolytic enzyme production test showed that 25(96.2%), 15(57.69%) and 14(53.84%) of isolates produced protease, chitinase and cellulase, respectively. Moreover, all (100%) and 6(23.07%) of the rhizobacterial isolates produced ammonia and hydrogen cyanide, respectively. Several isolates showed better growth at lower and higher temperature ranges and salt concentrations. Similarly, the majority of these isolates showed better resistance to the tested antibiotics and heavy metals with a decreased growth response to tetracycline and mercury. Elite isolates (WUFBI 6A and WUFBI 9D) which showed the highest performance in all the tests can be recommended as inoculants for application under greenhouse conditions and field test.</p> Mussa Adal* Gedefaw Wubie Kedija Adem Copyright (c) 2022 Abyssinia Journal of Science and Technology https://creativecommons.org/licenses/by-nc/4.0 2022-06-30 2022-06-30 7 1 1 10 10.20372/ajst.2022.7.1.429 Isolation and Screening of Keratinolytic Protease-Producing Bacteria from Soil in Abattoir Waste Disposal Area, Dessie, Ethiopia https://journals.wu.edu.et/index.php/ajst/article/view/467 <p>Management of keratin wastes with the help of microorganisms is a biotechnological alternative for recycling and valorization of these biomaterials. Keratinase belongs to a class of proteases that can serve as an important tool to convert keratin-rich wastes into diverse value-added products that are used for many applications. Therefore, the aim of this study was to isolate and screen keratinolytic bacteria from soil in abattoir waste disposal area. Screening of protease-producing isolates was performed on the medium containing 1% skim milk powder and 1.5% agar at 37ºC. A total of 34 isolates were selected after growth on nutrient agar media. Among 34 isolates, 17 were showing proteolytic activity on the skim milk agar medium and 3 isolates (MD1, MD4 and MD10) showed a clear zone greater than 25 mm. These isolates were again subjected to secondary screening for sheep hair degradation, and all showed complete degradation of sheep hair between 204 h and 360 h. Isolate MD4 was selected as the potent bacterium because it can degrade sheep hair within 204 h and produced maximum level of keratinase (899.30U/ml). Based on its morphological and biochemical characteristics, MD4 was tentatively identified as <em>Bacillus</em> sp. The results of this study revealed that isolate MD4 might have potential biotechnological applications that involve hydrolysis of keratin. It can be also used to manage keratin wastes and produce value-added products from these wastes. If further research such as enzyme characterization and genetic improvement of the organism is conducted, the isolate would be a good source of keratinolytic protease.</p> Muhammed Seid Copyright (c) 2022 Abyssinia Journal of Science and Technology https://creativecommons.org/licenses/by-nc/4.0 2022-06-30 2022-06-30 7 1 11 20 10.20372/ajst.2022.7.1.467 Effect of Feeding Sweet Blue Lupin (Lupinus angustifolius L.) Haulm and Concentrate Mixture on Growth Performance and Carcass Characteristics of Washera Lambs https://journals.wu.edu.et/index.php/ajst/article/view/414 <p>An experiment was conducted to evaluate the feeding value of graded level of sweet blue lupin haulm and concentrate mixture in the diets of lambs. For the feeding trial, twenty-four yearling Washera lambs with initial body weight of 24.6 kg ± 0.57 were used. The design of the experiment was randomized complete block design. The four experimental feeds were sweet blue lupin haulm to concentrate mixture ratio of 0:453 g, 251 g:362 g, 503 g:272 g and 754 g:181 g per day per head, respectively. Natural pasture hay was used as a basal diet. Results showed that supplementation of sweet blue lupin haulm and concentrate mixture significantly increased total dry matter, crude protein and organic matter intakes. Supplementation of sweet blue lupin haulm and concentrate mixture improved the digestibility of crude protein by 4%. Average daily weight gain was higher for the groups supplemented by sweet blue lupin haulm and concentrate mixture (68.7-87.4 g/day). Carcass parameters were slightly lower for lambs supplemented with higher level of sweet blue lupin haulm, while those supplemented with concentrate mixture and up to 40% sweet blue lupin haulm did not show significant difference. It was concluded that supplementing of mixture of 80% or 60% concentrate mixture with 20% or 40% sweet blue lupin haulm, respectively, in natural pasture hay-based diet can serve as locally available protein source to partially substitute commercial concentrate feeds for Washera lambs in Ethiopia.</p> Misganaw Walie Likawent Yeheyis* Adebabay Adane Beyadglign Hunegnaw Yohanes Amsalu Shigdaf Mekuriaw Mehari Ayalew Yeshwas Tilahun Copyright (c) 2022 Abyssinia Journal of Science and Technology https://creativecommons.org/licenses/by-nc/4.0 2022-06-30 2022-06-30 7 1 21 28 10.20372/ajst.2022.7.1.414 Effects of Forest Fragmentation on Plant Diversity and Regeneration of Woody Species in Qenfot Dry Afromontane Forest, Northeastern Ethiopia https://journals.wu.edu.et/index.php/ajst/article/view/357 <p>Qenfote forest, which encompasses the remnant forest patches in northeastern Ethiopia, is undergoing fragmentation, leading to loss of habitat and then erosion of biodiversity. The theory of island biogeography describes that the number of species in oceanic islands can be affected by island size and isolation. This study intended to estimate the effect of patch size, and distance between patches (isolation) on the diversity and regeneration status of plant species. Stratified and proportional sampling strategies were implemented to collect data from forest patches. Forest patch size was identified by delineating each patch from Google Earth and distances between patches were also measured. Forest patches were grouped into three based on size (small 7 ha-20 ha, medium 20.1 ha-45 ha, and large above 45 ha) and into three isolation (distance apart) categories (nearest 0-4 km, medium 4.01 km-8 km, and far distance 8.01 km-11 km). For each category three replicated patches were selected and then systematic sampling was used to lay the transect lines within each nine sample patches. Vegetation data were collected from a total of 75 plots (20 m × 20 m) from every patch. Results showed that the number of species (species richness) found in small forests, medium forest patches, and large forest patches was 55±6.43, 66.67±7.96, and 77.67±10.42, respectively, while the Shannon diversity found in the small forests was 2.52±0.09, in medium forest patches 2.69±0.07 and in large forest patches 2.78±0.08. Both species diversity and species richness were increased with increasing patch size and decreased as distance increased from largest patch. Thus, we concluded that fragmentation in Qenfote forests affects plant diversity and regeneration status, a finding that supports the demands for forest restoration.</p> Famos Assefa* Tsegaye Gobezie Copyright (c) 2022 Abyssinia Journal of Science and Technology https://creativecommons.org/licenses/by-nc/4.0 2022-06-30 2022-06-30 7 1 29 38 10.20372/ajst.2022.7.1.357 Response of Potato Varieties to Nitrogen Fertilizer Rates in Debark District, Northwestern Ethiopia https://journals.wu.edu.et/index.php/ajst/article/view/417 <p>Potato (<em>Solanum tuberosum</em> L.) is one of the most important vegetable crops in the highlands of Ethiopia. However, its productivity is very low mainly due to soil infertility, lack of site-specific fertilizer recommendation and appropriate varieties<strong>. </strong>Therefore, a study was conducted in 2019 under irrigation to evaluate the response of improved potato varieties to different rates of nitrogen fertilizer rates. The treatments comprised of four nitrogen rates (0, 55, 110 and 165 kg ha<sup>-1</sup>) and three potato varieties (Belete, Gudene and Local), which were laid in a randomized complete block design with three replications. The analysis of variance revealed that the main effects of nitrogen rates and varieties significantly influenced the tested growth, yield and yield related traits of potato. The maximum marketable tuber yield (30.70 t ha<sup>-1</sup>) was recorded from application of 110 kg nitrogen ha<sup>−1</sup>, which increased tuber yields by 86% as compared to unfertilized plots. Among the tested varieties, Belete produced the highest marketable yield (29.8 t ha<sup>-1</sup>) with a yield advantage of 71% compared to the local variety. The partial budget analysis result showed that application of nitrogen 110 kg nitrogen ha<sup>−1</sup>for Belete variety gave the highest profit (205787ETB ha<sup>-1</sup>) with acceptable marginal rate of return (485%). From the present result, it can be concluded that optimum yield and high profit can be obtained by applying110 kg nitrogen ha<sup>−1 </sup>for Belete variety.</p> Yenus Ouusman Kemal* Gebrie Getie Alemu Tiru Tesfa Belachew Copyright (c) 2022 Abyssinia Journal of Science and Technology https://creativecommons.org/licenses/by-nc/4.0 2022-06-30 2022-06-30 7 1 39 45 10.20372/ajst.2022.7.1.417 The Effects of Nitrogen Rates on Yield, and Yield Components of Improved Sorghum Varieties in the lower watersheds of Habru District, Northern Ethiopia https://journals.wu.edu.et/index.php/ajst/article/view/452 <p>Nitrogen is the most limiting nutrient for the growth and development of sorghum; as in most Ethiopia soils, the soils of the study areas are deficient in nitrogen because of over cultivation of the land. Hence, this research was designed to study the effects of nitrogen rates on yield and yield components of improved sorghum varieties in the three lower watersheds of Habru district, northern Ethiopia. Factorial combinations of nitrogen rates (0, 46, 69, 92, and 115kg N ha<sup>-1</sup>) and two sorghum varieties (Melkam and Girana 1) were arranged in a randomized complete block design with three replications. The experiment was conducted in three watersheds for two years. The analysis of variance showed that all the combined seasons and locations for the growth, yield, and yield-related traits of sorghum parameters were significantly (p&lt;0.05) affected by the interaction of nitrogen rates and varieties except plant height which was significantly affected by the main effects of nitrogen and varieties only. Almost all the yield and yield-related parameters had shown a significant increase up to the rate of 92 kg N ha<sup>-1</sup>. The partial budget analysis showed that the treatment combination of Melkam with 92 kg N ha<sup>-1</sup> gave the highest marginal rate of return of 4321% followed by Melkam with 69 kg N ha<sup>-1</sup>. Applying nitrogen to sorghum increased its productivity. Thus, the application maximizes yield of Melkam variety resulted in maximum profit and can be recommended for the study area<em>.</em></p> Mohammed Hussen Shibeshi* Moges Tadesse Gedamu Alemu Molla Fiseha Copyright (c) 2022 Abyssinia Journal of Science and Technology https://creativecommons.org/licenses/by-nc/4.0 2022-06-30 2022-06-30 7 1 46 53 10.20372/ajst.2022.7.1.452 Postpartum Anestrous and Risk Factors in Crossbreed Dairy Cows in Northern Central Highland of Ethiopia https://journals.wu.edu.et/index.php/ajst/article/view/461 <p>The study was carried out to determine the prevalence and incidence of postpartum anestrous problems and its associated risk factors in crossbred dairy cows in northern central highland of Ethiopia. Retrospective and longitudinal study was used to gather data on the occurrence of postpartum anestrus and the associated risk factors in crossbred cows. The prevalence and incidence of postpartum anestrous were 39.7% and 40.95%, respectively. Risk factors such as age, parity, body condition, milk yield, management condition, herd size, heat detection practices and predisposing reproductive problems had significant influence on the prevalence and incidence of postpartum anestrous in crossbred dairy cows. Postpartum anestrous was significantly aggravated as the age, parity and milk yield of dairy cows increased. The highest occurrences of postpartum anestrous was identified in crossbred dairy cows with poor body condition score, large herd size, poor management condition, inaccurate heat detection practice and in crossbred dairy cows that had a history of reproductive problems during the previous calving. Maintaining optimal body condition score of cows, farmers’ awareness creation on management condition, i.e., how to improve their farm hygiene, feed and feeding dairy cow, and health care and handling animals during and after parturition would increase the number of cows ready for breeding by 60 days postpartum.</p> Tewodros Eshete Bereded* Tilaye Demisse Tefera Yilma Berhan Tamir Copyright (c) 2022 Abyssinia Journal of Science and Technology https://creativecommons.org/licenses/by-nc/4.0 2022-06-30 2022-06-30 7 1 54 61 10.20372/ajst.2022.7.1.461 In-vitro Antibacterial Activity of Common Spices against Isolated Lactic Acid Bacteria and Their Sensory Quality Role in Fermented Camel Milk https://journals.wu.edu.et/index.php/ajst/article/view/333 <p>The aim of this study was to evaluate the antibacterial activities of common spices on the growth of lactic acid bacteria (LAB) isolated from camel and the consumer acceptability of adding isolated lactic acid bacteria LAB into fermented camel milk. The experiment was conducted with fifteen isolated LABs and eight commonly used spices in Ethiopia. After clean the spices were grinding with a mill under aseptic conditions in order to obtain spice extracts. The extracts were sieved and sterilized with a membrane and each 50g spice powder was extracted individually in 250mL methanol and distilled autoclaved water for 24 hours. The filtered solvent was evaporated under reduced pressure using a rotary evaporator at 55°C after 24 hours of shaking. The results revealed that different extracted spices at varied concentrations influenced the growth of isolated LABs. P. acidilactici 226NB has the greatest inhibitory zone was obtained in Ground Elder (Nechazmud) and Fenugreek (Abish) at 100, 75, and 50% concentrations. Ground Elder (Nechazmud), Black Pepper (Qundo Berbere), Garlic (Nech Shinkurt), Turmeric (Ird), and Rue (Tena'adam) were all found to inhibit the growth of isolated LABs at a concentration of 25%. Only P. pentosaceus 301A, E. faecium 210NB, L.casei subsp. casei 143NB, and P.acidilactici 226NB revealed a distinct zone at 12.5% concentration of methanol extracted by Paprika Pepper (Berbere), Black Cumin Seeds, Fenugreek (Abish), and Ground Elder. Sensory evaluation of pasteurized fermented camel milk with LAB isolates received moderately positive responses from panelists.The aim of this study was to evaluate the antibacterial activities of common spices on the growth of lactic acid bacteria (LAB) isolated from Ethiopian traditionally fermented camel milk and the consumer acceptability of adding isolated LAB to fermented camel milk. The experiment was conducted at Haramaya University between April and December 2021 with fifteen isolated LABs obtained from the Holeta Agricultural Biotechnology Research Center and eight spices commonly used in Ethiopia. The antibacterial activity of each extracted spice was assessed using the disc diffusion method. Spice extracts were evaluated on different test-isolated LABs at 12.5%, 25%, 50%, 75%, and 100% to check if they had antibacterial activity. The sensory evaluation of the fermented camel milk samples was done by seventeen experienced panelists. The results revealed that different extracted spices at varied concentrations influenced the growth of isolated LABs. Ground elder and fenugreek at 100%, 75%, and 50% concentration for P. acidilactici 226NB had the greatest inhibitory effect recorded. Ground elder, black pepper, garlic, turmeric, and rue inhibited the growth of some LABs at a concentration of 25%. Black cumin seeds, fenugreek, and ground elder at 12.5% concentration inhibited the growth of E. faecium 210NB, P. acidilactici 226NB, and P. pentosaceus 301A, respectively. The sensory evaluation showed isolated LABs received ratings of ‘moderately liked’ and ‘slightly liked’ colour, aroma, texture, taste and overall acceptability from panelists. All methanol extracted spices were positive, while glycosides were negative for Allium Sativum, according to phytochemical results.</p> Gezu Tadesse Mammo* Mitiku Eshetu Guya Ameha Kebede Tesfaye Yonas Hailu Alemu Tesfemariam Berhe Firew Kassa Esho Copyright (c) 2022 Abyssinia Journal of Science and Technology https://creativecommons.org/licenses/by-nc/4.0 2022-06-30 2022-06-30 7 1 62 71 10.20372/ajst.2022.7.1.333