Isolation, Identification and In-Vitro Fermentation Activity of Cellulolytic Bacteria from the Gut of Termites

Termites are known for their ability to digest high lignocellulolytic compounds, such as wood and fiber materials. Ruminants with the aid of their microorganisms are able to digest fiber materials, however the percentage of digestion is not so high. Therefore, the main objectives of this study were to isolate and identify cellulolytic bacteria from the termites gut and to determine the ability of these bacteria to improve the digestibility of fibrous feed materials by the rumen microflora using the in-vitro gas production technique. In this study, cellulolytic bacteria isolated from the gut of termites were used to mix with the rumen microflora on fiber material digestion. Termites were obtained from decayed plant materials and nests from different locations in the vicinity of Universiti Putra Malaysia (UPM). They were identified as the lower termite Coptotermes curvignathus (Holmgren) and the higher termite Macrotermes gilvus (Hagen). Cellulolytic bacteria from the gut of the lower termite; Coptotermes curvignathus (Holmgren) was isolated. The isolates were cultured aerobically in a medium containing carboxymethylcellulose (CMC) at temperature of 30°C. The five isolates obtained were identified based on the Biolog reader chemical test, Bergy' s Manual and 1 6S rRNA sequence homology. The species were identified as: Bacillus cereus (isolate 1), Acinetobacter baumanni (isolate 5), Enterobacter aerogenes (isolate 2), Enterobacter cloacae (isolate 3) and Chryseobacterium kwangyangense (isolate 4). The Gene Bank NCBI/EMBL accession numbers for the bacterial isolates are EU294508, EU332791, EU305608, EU305609, and EU 169201 respectively. Acinetobacter baumanni isolate 5 is an aerobic bacterium, while the other four species are facultative anaerobes. The first invitro experiment by the gas production technique was conducted to examine the digestion and volatile fatty acid production by the five bacterial species grown in the rice straw medium. There were significant differences (P<0.05) in dry matter loss (DM) of rice straw and acetic acid concentration among the five bacterial species. A cinetobacter baumanni isolate 5 showed the highest fermentation activity (7.76 mM). The second in-vitro experiment also by gas production technique, which was conducted to determine the effect of adding rumen fluid microflora on rice straw digestion. The bacterial cultures were standardized to an OD of 0.5 (108 CFU/ml) before adding to the rumen fluid micro flora. Rumen fluid was obtained from a fistulated cattle maintained on a grass diet. The facultative bacteria tested were C. kwangyangense isolate 4, E. cloacae isolate 3 and E. aerogenes isolate 2. Digestion of rice straw by rumen fluid microflora was determined with or without adding individual cultures of termites gut bacterial species

DISTRIBUTION NETWORK OPERATION WITH SOLAR PHOTOVOLTAIC AND ENERGY STORAGE TECHNOLOGY

Among distributed energy resources, solar photovoltaic (PV) generation has the largest penetration in the distribution networks. Serving electric vehicles (EV) with renewable resource generation would further reduce the carbon footprint of the energy supply chain for electric vehicles. However, the integration of solar PV and EVs in the unbalanced distribution network introduces several challenges including voltage fluctuations, voltage imbalances, reverse power flow, and protection devices’ malfunctions. The uncertainties associated with solar PV integration and electric vehicles operation require significant effort to develop accurate optimization methodologies in the unbalanced distribution systems operation. In this thesis, in order to cope with the uncertainties, we first developed a two-stage optimization problem, to identify the feasible dispatch margins of photovoltaic generation considering the distribution network operation constraints. The dispatch margins of photovoltaic generation are quantified considering the worst-case realization of demand in the distribution network. The linear and the second-order cone mathematical problem formulation is procured to solve the optimal power flow problem. Second, a data-driven distributionally robust optimization framework is proposed for the operation of the unbalanced distribution network considering the uncertainties associated with the interconnected EV fleets and solar PV generation, and the proposed framework leverages the column-and-constraint generation approach. Moreover, to minimize the operation cost and improve the ramping flexibility, a continuous-time optimization problem, is developed and reformulated to a linear programming problem using Bernstein polynomials. Here, a generalized exact linear reformulation of the data-driven distributionally robust optimization is used to capture the worst-case probability distribution of the net demand uncertainties. Furthermore, in this thesis, an interconnection of multi microgrids (MGs) technology is considered a promising solution to handle the variability of the distributed renewable energy resources and improve the energy resilience in the distribution network. The coordination among the microgrids in the distribution network could improve the operation cost, reliability, and security of the distribution network. Therefore, an adaptive robust distributed optimization framework is developed for the operation of a distribution network with interconnected microgrids considering the uncertainties in demand and solar PV generation

Effects of herd management decisions on dairy cow longevity, farm profitability, and emissions of enteric methane - a simulation study of milk and beef production

Sustainable dairy and beef production provides environmental, economic, and social values that can potentially be maximized by optimizing herd management strategies. The length of a dairy cow's life is affected by, and affects, all three pillars of sustainability. Longevity in dairy cows is multifactorial and strongly dependent on herd management. Despite genetic improvements, the average time of culling for Swedish cows has barely changed and is currently at 2.6 lactations. This culling rate requires a high number of replacement heifers, generating high rearing costs for farmers. This study evaluated different herd management strategies to improve cow longevity and assessed the effects on enteric methane (CH4) emissions from the herd and the profitability of milk production and beef production from the dairy cows and their offspring. The base scenario, an average Swedish Holstein herd of 100 cows, was compared with seven scenarios simulated using a stochastic herd simulation model (SimHerd). Two of these scenarios involved improved health and survival of cows in the herd, three involved improved reproduction, one considered the consequences of keeping all surplus heifers in the herd, and one considered maximizing the use of X-sorted dairy semen and inseminating the rest of the herd with unsorted beef semen, to avoid surplus replacement heifers. Improved fertility had the greatest effect in increasing the productive life per cow, to 3.8 years compared with 2.8 in the base scenario, allowed for more use of beef semen, reduced the number of replacement heifers, and generated the highest herd profit (698 per cow-year higher than base scenario). Keeping all surplus heifers instead of producing beef x dairy cross calves decreased the number of productive years by 0.8 and reduced profit by 622 per cow-year. The profit was highly associated with costs related to replacement heifers. The highest beef output (3 369 kg per year more than base scenario) was achieved by keeping all heifers and culling a high share of dairy cows, but this scenario also generated much higher enteric CH4 emissions (+1 257 kg per year). Improving health, survival, or fertility reduced enteric CH4 emissions by 90-255 kg per year, while total yearly beef production ranged from 59 kg less to 556 kg more than in the base scenario. Reducing the number of replacement heifers needed by improving cow reproductive performance is thus key to increasing cow longevity and profitability, while reducing enteric CH4 emissions from the herd without compromising milk and meat production. (c) 2023 The Author(s). Published by Elsevier B.V. on behalf of The Animal Consortium. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Contemporary approaches to measuring and estimating methane emission from ruminants

This review aims to elucidate the contemporary methods of measuring and estimating methane (CH4) emissions from ruminants. Six categories of methods for measuring and estimating CH4 emissions from ruminants are discussed. The widely used methods in most CH4 abatement experiments comprise the gold standard respiration chamber, in vitro incubation, and the sulfur hexafluoride (SF6) techniques. In the spot sampling methods, the paper discusses the sniffer method, the GreenFeed system, the face mask method, and the portable accumulation chamber. The spot sampling relies on the measurement of short-term breath data adequately on spot. The mathematical modeling methods focus on predicting CH4 emissions from ruminants without undertaking extensive and costly experiments. For instance, the Intergovernmental Panel on Climate Change (IPCC) provides default values for regional emission factors and other parameters using three levels of estimation (Tier 1, 2 and 3 levels), with Tier 1 and Tier 3 being the simplest and most complex methods, respectively. The laser technologies include the open-path laser technique and the laser CH4 detector. They use the laser CH4 detector and wireless sensor networks to measure CH4 flux. The micrometeorological methods rely on measurements of meteorological data in line with CH4 concentration. The last category of methods for measuring and estimating CH4 emissions in this paper is the emerging technologies. They include the blood CH4 concentration tracer, infrared thermography, intraruminal telemetry, the eddy covariance (EC) technique, carbon dioxide as a tracer gas, and polytunnel. The emerging technologies are essential for the future development of effective quantification of CH4 emissions from ruminants. In general, adequate knowledge of CH4 emission measurement methods is important for planning, implementing, interpreting, and comparing experimental results

The Electrochemical Syntheses And Characterizations Of Nickel Nanoparticles And Zinc-Nickel Nanoalloy On Composite Graphite Substrate

Nanohablur nikel (Ni) dengan purata saiz 9.7 ± 2.3 nm dimendapkan ke atas komposit elektrod grafit daripada larutan saduran 5.0 mM NiCl2.6H2O dan 1.0 M NH4Cl menggunakan kadar imbasan 6500 mVs-1. The nickel (Ni) nanocrystals with an average size of 9.7 ± 2.3 nm were deposited onto composite graphite electrode from a plating solution of 5.0 mM NiCl2.6H2O and 1.0 M NH4Cl using scan rate of 6500 mVs-1. The initial potential −1.5 V vs. Ag/AgCl, final potential −0.5 V and applied time 120 s were used for the whole deposition process

Evaluation of Atorvastatin Safety on Liver Function Tests, a Prospective Study

Background: Although lipid lowering agents as statins are used frequently in hyperlipidemic patients as well as patients with cardiac disease, they could have major hepatic side effects, the aim of this study is to evaluate the safety of statins mainly atorvastatin on liver as estimated by liver aminotransferase assay.Materials and Methods: Patients with indication of atorvastatin were included the study. As a before and after study all the patients underwent serum level measurement of aminotransferases at the beginning and after three month of taking the drug.Results and Conclusion: HMG-COA reductase as atorvastatin should be safe in different doses 20,40 and 80 mg in patient with hyperlipidemia with and without cardiac disease without significant hepatotoxicity