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用于水产养殖的商业芽孢杆菌益生菌的安全性评价

2020年

作者：阿贝娜·达兹-阿瑟(abena Dadze-Arthur)

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用于水产养殖的商业芽孢杆菌益生菌的安全性评价

作者： Anokyewaa Melody abena 广东海洋大学

学位级别：硕士

疾病是水产养殖所面临的重要制约因素,对其进行预防和控制是近期研究的重点。一些资源和措施已被用于预防水产养殖中的疾病。益生菌是有益的天然衍生物,在水产养殖中具有多种益处。目前,在水产养殖业中使用了几种商业益生菌,其中含有一... 详细信息

疾病是水产养殖所面临的重要制约因素,对其进行预防和控制是近期研究的重点。一些资源和措施已被用于预防水产养殖中的疾病。益生菌是有益的天然衍生物,在水产养殖中具有多种益处。目前,在水产养殖业中使用了几种商业益生菌,其中含有一种或多种活微生物。芽孢杆菌属是水产养殖业中使用最广泛的益生菌之一,它们被认为是独特的,并被发现是某些鱼类肠道微生物群的天然成员。有益微生物的安全性至关重要,因为有研究发现其中一些微生物具有可能转移给宿主的特征。已有多项研究调查和证明了芽孢杆菌属物种的益生菌特性,被认为是人类和动物中使用最广泛的商业益生菌之一。在水产养殖中,体外和体内研究也提供了关于芽孢杆菌在添加到养殖水体或饲料中对养殖生物有效的验证。然而,关于抗生素耐药性以及有益微生物中毒力和抗生素耐药基因(ARGs)流行的问题目前正在上升。抗生素耐药性问题已成为中国公众关注的问题,因为在全国各地,包括沉积物、水面、土壤等发现了多种抗生素耐药基因(ARGs)。本研究以水产养殖中使用的芽孢杆菌类商业益生菌为研究对象,对其毒力和耐药基因的流行、溶血活性、组胺产生、DNase活性和抗生素的敏感性方面进行了安全性评估。1.本研究购买了32种用于水产养殖的基于芽孢杆菌的商业益生菌制剂,将样品溶解在无菌磷酸盐缓冲液(PBS)中,混匀,然后接种到LB琼脂板上。随机挑取不同的细菌菌落并在LB液体培养基中培养12 h。进行重新划线以确保从单一物种中分离出纯菌株。从形态学和生化测试对分离的细菌进行表征,并通过16S r RNA基因序列分析进行鉴定。结果表明,一些商业益生菌不含或含有少于标签上标明的微生物。在其他一些中,当铺在琼脂板上时没有观察到细菌生长。一些样本也没有任何已知的芽孢杆菌物种,而是一些含有被认为是致病的细菌。2.经过分离鉴定,筛选出芽孢杆菌的毒力基因(nhe A、nhe B、nhe C、hbl A、hbl C、hbl D、cyt K、ent FM)和一个催吐基因(ces),以及对某些抗生素的耐药性。大多数分离株不具备任何评估的毒力基因。尽管如此,有三株分离株携带nhe A、nhe B、nhe C和ent FM肠毒素基因,有两株分离株具有hbl A、hbl C、hbl D、cyt K基因。所有分离株均无ces催吐基因。19种抗生素用于抗生素敏感性测试。抗生素耐药性评估显示,大多数分离株对β-内酰胺类抗生素耐药,包括青霉素、氨苄西林、头孢呋辛、头孢曲松和链霉素。此外,结果显示70%以上的菌株对环丙沙星、氯霉素、妥布霉素、万古霉素、阿米卡星、头孢曲松、庆大霉素、强力霉素、卡那霉素、苯唑西林、头孢呋辛、米诺环素、苯唑西林敏感。3.此外,在所有芽孢杆菌中对编码耐药性蛋白的基因进行筛选(tet M、tet K、tet L、cat、van A、van C aac(6′)-Ie-aph(2″)-la.、ant(4′)-Ia(adenylyltransferase,Bcr R,mec A,bla,erm B,vat C)。PCR筛选报告了分离株中ARGs的存在,包括tet K、tet L、van A、van C、ant(4’)-Ia(腺苷酸转移酶)、erm B和vat C。表型和基因组之间的关系描述了一些分离株可能表现出沉默抗性,这也可能是获得性抗性。4.对其他安全性参数也进行了研究,包括溶血试验、DNA酶试验和hdc基因筛选。只有1株分离株(CMPF 4蜡状芽孢杆菌)表现出β-溶血活性;所有分离株均不表达组氨酸脱羧酶(hdc)基因;12株分离株的DNase测试结果呈阳性。由于益生菌通常被视为有益微生物并被归类为有益微生物,正如它们的名称所描述的那样,它们需要最佳的安全性,以确保它们实现其目标。本研究中,观察到一些市售的商业益生菌的安全性是值得怀疑的,即使从益生菌种类的鉴定来看也是如此。基于毒力和耐药性因素,本研究中购买的13种商业益生菌存在安全问题。此外,一些商业制剂被标签上未说明的非益生菌微生物污染。商业益生菌的生产商和制造商必须妥善处理这些错误,以确保市场上有安全的商业益生菌可供养鱼者为其业务购买。

关键词：商业益生菌、毒力基因、抗生素耐药性、芽孢杆菌属水产养殖

Thermal and Physicochemical Characterization of Fibers from Coffee hulls as Filler for Linear Low Density Polyethylene (LLDPE)

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Advances in Materials Physics and Chemistry 2021年第10期11卷 155-166页

作者： Ahmat Tom Abel Tame Paul Nestor Djomou Djonga Bakary Tigana Djonse Justin Eugenie Géraldine Nga abena Department of Energy Engineering University Institute of Technology University of Ngaoundere Ngaoundere Cameroon Department of Chemistry Faculty of Science University of Yaoundé I Yaoundé Cameroon Department of Textile and Leather Engineering National Advanced School of Engineering of Maroua Maroua Cameroon Department of Chemistry Faculty of Science University of Maroua Maroua Cameroon Department of Physics Faculty of Science University of Yaoundé I Yaoundé Cameroon

This work presents the thermal, physical and chemical characterization of Coffee canephora, from littoral region of Cameroon, for their use as.reinforcement for polymeric materials. The infrared of coffee hulls shows ... 详细信息

This work presents the thermal, physical and chemical characterization of Coffee canephora, from littoral region of Cameroon, for their use as reinforcement for polymeric materials. The infrared of coffee hulls shows the presence of a large peak intensity at 3299 cm-1 that can be attributed to O-H stretching group of alcohol (cellulose content in coffee pulp). The intensity 2926 cm-1 can be attributed to C-H stretching group of alkanes or the vibration of methoxy group of lignin. Thermo gravimetric analysis shows that around 440°C, the biomass has been completely consumed;the temperature profiles show a peak at 86°C that could correspond to the loss of water as evaporation at a percentage of 8%;the peak at 321°C is accompanied by a water loss of 64.50%;hite-space:normal;font-family:;" "=""> this temperature is assimilated to the degradation of hemicelluloses;the temperature range from 321°C to 401°C is accompanied by a loss of mass of 22.80%, which would be due to the degradation of cellulose. SEM images of the surface of raw coffee hulls, coffee hulls treated with caustic soda respectively clearly reveal gaps between the fibers. The results showed that the incorporation of coffee hulls fiber in LLDPE matrix might result in composites with suitable property application for various industrial fields

关键词： Characterization Coffee hulls Filler LLDPE Physicochemical and Thermal

Spatiotemporal Analysis of COVID-19 Lockdown Impact on the Land Surface Temperatures of Different Land Cover Types in Louisiana

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Journal of Geographic Information System 2023年第5期15卷 458-481页

作者： Priscilla M. Loh Yaw A. Twumasi Zhu h. Ning Matilda Anokye Diana B. Frimpong Judith Oppong abena B. as.re-ans.h recheal N. D. Armah Caroline Y. Apraku Department of Urban Forestry Environment and Natural Resources Southern University and A&M College Baton Rouge USA

The COVID-19 pandemic posed a serious threat to life on the entire planet, necessitating the imposition of a lockdown mechanism that restricted people’s movements to stop the disease’s spread. This period experienced a decline in air pollution emissions and some environmental changes, offering a rare opportunity to understand the effects of fewer human activities on the earth’s temperature. hence, this study compares the changes in Land Surface Temperature (LST) that were observed prior to the pandemic (March & April 2019) and during the pandemic lockdown (March & April 2020) of three parishes in Louisiana. The data for this study was acquired using Landsat 8 Thermal Infrared Sensor (TIRS) Level 2, Collection 2, Tier 2 from the Google Earth Engine Catalog. For better visualization, the images that were derived had a cloud cover of less than 10%. Also, images for the three study areas were processed and categorized into four main classes: water, vegetation, built-up areas, and bare lands using a Random Forest Supervised Classification Algorithm. To improve the accuracy of the image classifications, three Normalized Difference Indices namely the Normalized Difference Vegetation Index (NDVI), Normalized Difference Water Index (NDWI) and Normalized Difference Built-Up Index (NDBI) were employed using the Near Infrared (NIR), red, Green and SWIR bands for the calculations. After, these images were processed in Google Earth Engine to generate the LST products gridded at 30 m with a higher spatial resolution of 100 m according to the pre-pandemic (2019) and lockdown (2020) periods for the three study areas. results of this study showed a decrease in LST values of the land cover classes from 2019 to 2020, with LST values in East Baton Parish decreasing from 44°C to 38°C, 42°C to 38°C in Lafayette Parish, and 43°C to 38°C in Orleans Parish. The variations in the LST values therefore indicate the impact of fewer anthropogenic factors on the earth’s temperature which requires

关键词： Urban heat Island Anthropogenic Activities Greenhouse Gas Greenspace Wetlands

Assessing the Impact of Land Use and Land Cover Change on Air Quality in East Baton Rouge—Louisiana Using Earth Observation Techniques

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Advances in remote Sensing 2022年第3期12卷 106-119页

作者： Diana B. Frimpong Yaw A. Twumasi Zhu h. Ning abena B. as.re-ans.h Matilda Anokye Priscilla M. Loh Faustina Owusu Caroline Y. Apraku recheal N. D. Armah Judith Oppong John B. Namwamba Department of Urban Forestry and Natural resources Southern University and A & M College 102 Fisher Hall Baton Rouge Louisiana USA

There has been significant research in recent decades on Land use Land cover (LULC) changes and their influence on biodiversity but little to no research on its impact on air quality. This research seeks to demonstrate how geospatial technologies such as geographic information system (GIS) and remote sensing can be used to assess the effects of LULC changes on particulate matter emissions and their impact on air quality in the East Baton Rouge area. In pursuit of these objectives, this study uses LANDSAT imageries from the past 30 years specifically Landsat Thematic Mapper (TM C2L2) and Landsat 8 Operational Land Imager/Thermal Infrared (OLI/TIRS C2L2) covering 1991, 2001, 2011 and 2021 were collected, processed, and analyzed for the LULC change analysis using QGIS software. Additionally, Sentinel 5P and the Air quality index from the U.S. Environmental Protection Agency (EPA) were used to assess the air quality trend over the years to establish the correlation between LULC and air quality. results showed an increasing trend in air quality over the past 3 decades with concentrations of CO, NO2, and PM2.5 abruptly falling however, urbanization and the population expanded throughout the time. The paper concludes by outlining a policy recommendation in the form of encouraging Louisiana residents to use alternative renewable energies rather than the over-dependence on coal-fired electric generating plants that have an impact on the environment.

关键词： Google Earth Engine Aerosol Air Quality Sentinel-5P Land Use Land Cover Change

cagAand vacAhelicobacter pyloriPathogenicity Factors in Brazzaville, Congo

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Open Journal of Medical Microbiology 2019年第4期9卷 186-200页

作者： E. N. Ontsira Ngoyi C. Guilloteau L. Benejat A. Mongo Onkouo A. Buissonnière E. Sifre A. Aloumba Tanguy Mieret F. Bossali F. Yala A. A. abena J. Vadivelu K. L. Goh J. R. Ibara B. I. AtipoIbara A. Menard P. Lehours F. Megraud Equipe 2 helicobacter pylori infection inflammation and cancer Inserm U1053 Bordeaux university Bordeaux France health Sciences Faculty Marien Ngouabi University Brazzaville Congo French National reference Center for helicobacters and Campylobacters Bordeaux France University of Malaya Kuala Lumpur Malaysia Bacteriology laboratory Pellegrin University Hospital Bordeaux France

Introduction: CagA and VacA are the most important and well-studied virulence factors found in helicobacter pylori. The aim of this work was to identify genes corresponding to h. pylori pathogenicity factors in Brazzaville, Congo. Material & Methods: A cross-sectional study was carried out from October 2013 to December 2016. Biopsy specimens were obtained from patients scheduled for upper gastrointestinal endoscopy in Brazzaville, Congo and were sent to the French National reference Center for Campylobacters and helicobacters in Bordeaux, France. h. pylori detection was conducted by real-time PCR using a fuorescence resonance energy transfer-melting curve analysis protocol. The identification of the genes encoding pathogenicity factors was carried out by conventional PCR using the appropriate primers for determination of CagA phosphorylation motifs 1, 2, 3;and vacAs, I and m regions: vacAi1, vacAi2, vacAs1a, vacAs1b. results: A high prevalence of h. pylori infection was.reported (108/143;75.5%). In 92.2% (n = 71/77), the presence of P1, P2 and P3 CagA phosphorylation motifs was noted. Concerning vacA, vacAs1m1 was observed in 82% of the strains (n = 59/72). vacAi1 was present in all strains (n = 76). With regard to the distribution according to the vacAs1 subtype, the majority of the strains (59/71;83%) were vacAs1b positive, as compared to vacAs1c (17/34, 33%). The vacAs1a gene was absent in all of these patients. Conclusion: The presence of genes associated with severe gastric diseases indicates the importance of h. pylori eradication in the prevention of these diseases in Congo.

关键词： Pathogenicity Factors CagA VacA

An Assessment of the Potential Use of Forest residues for the Production of Bio-Oils in the Urban-Rural Interface of Louisiana

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Open Journal of Forestry 2022年第4期12卷 479-502页

作者： Yaw A. Twumasi Zhu h. Ning John B. Namwamba Edmund C. Merem abena B. as.re-ans.h harriet B. Yeboah Matilda Anokye Diana B. Frimpong Priscilla M. Loh Julia Atayi Judith Oppong Cynthia C. Ogbu rechael N. D. Armah Caroline Y. Apraku Opeyemi I. Oladigbolu Joyce McClendon-Peralta Department of Urban Forestry and Natural resources Southern University and A&M College Baton Rouge USA Department of Urban and regional Planning Jackson State University Jackson USA Department of Geography and Tourism Studies Brock University St. Catharines Canada

Louisiana is endowed with forest resources. Forest wastes generated after thinning, land clearing, and logging operations, such as wood debris, tree trimmings, barks, sawdust, wood chips, and black liquor, among others, can serve as potential fuels for energy production in Louisiana. This paper aims to evaluate the potential annual volumes of forest wastes established on detailed and existing data on the forest structure in the rural-urban interface of Louisiana. It also demonstrates the state’s prospects of utilizing forest wastes to produce bio-oils. The data specific to the study was deduced from secondary data sources to obtain the annual average total residue production in Louisiana and estimate the number of logging residues available for procurement for bioenergy production. The total biomass production per year was modeled versus years by polynomial regression curve fitting using Microsoft Excel. results of the model show that the cumulative annual total biomass production for 2025 and 2030 in Louisiana is projected to be 80000000 Bone Dry Ton (BDT) and 16000000 (BDT) respectively. The findings of the study depict that Louisiana has a massive biomass supply from forest wastes for bioenergy production. Thus, the potential for Louisiana to become an influential player in the production of bio-based products from forest residues is evident. The author recommends that future research can use Geographic Information Systems (GIS) to create maps displaying the potential locations and utilization centers of forest wastes for bioenergy production in the state.

关键词： Bioenergy Production Bio-Oils Polynomial regression Bio-Products Forest residues Logging residues Wood Wastes Louisiana

Time Series Analysis on Selected Rainfall Stations Data in Louisiana Using ARIMA Approach

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Open Journal of Statistics 2021年第5期11卷 655-672页

作者： Yaw A. Twumasi Jacob B. Annan Edmund C. Merem John B. Namwamba Tomas Ayala-Silva Zhu h. Ning abena B. as.re-ans.h Judith Oppong Diana B. Frimpong Priscilla M. Loh Faustina Owusu Lucinda A. Kangwana Olipa S. Mwakimi Brilliant M. Petja Ronald Okwemba Caroline O. Akinrinwoye hermeshia J. Mosby Joyce McClendon-Peralta Department of Urban Forestry and Natural resources Southern University and A&M College Baton Rouge Louisiana USA Department of Urban and regional Planning Jackson State University Jackson Mississippi USA USDA-ARS Tropical Agriculture research Station Mayaguez Puerto Rico USA Institute of resource Assessment University of Dares Salam Dares Salam Tanzania Water research Commission (WRC) Private Bag X03 Gezina South Africa

Precipitation is very important for both the environment and its inhabitants. Agricultural activities mostly depend on precipitation and its availability. Therefore, the ability to predict future precipitation values at specific stations is key for environmental and agricultural decision making. This research developed Autoregressive Integrated Moving Average (ARIMA) models for selected stations with Integrated component and Autoregressive Moving Average (ARMA) for selected stations without Integrated component at Louisiana State. The ARIMA module is represented as ARIMA(p, d, q)(P,D,Q). The selected lag order for the Autoregressive (AR) component is represented with p and P for seasonal AR component, while the integrated form (number of times data were differenced) is d and D for seasonal differencing, and the Moving Average (MA) lag order is q and Q for seasonal MA component. Data from 1950 to 2020 were employed in this research. results of the analysis indicated that Baton Rouge (ARIMA (0,1,1) (0,0,2)12), Abbeville (ARMA (0,0,1) (0,0,2)12), Monroe Regional (ARMA (0,0,1) (0,0,0)12), New Orleans Airport (ARMA (1,0,0) (0,0,2)12), Alexandria (ARMA (1,0,1) (0,0,0)12), Logansport (ARIMA (0,1,2) (0,0,0)12), New Orleans Audubon (ARMA (1,0,0) (0,0,0)12), Lake Charles Airport (ARMA (2,0,2) (0,0,0)

关键词： Precipitation ARIMA Models Time Series Lowess Louisiana

Estimation of Land Surface Temperature from Landsat-8 OLI Thermal Infrared Satellite Data. A Comparative Analysis of Two Cities in Ghana

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Advances in remote Sensing 2021年第4期10卷 131-149页

作者： Yaw A. Twumasi Edmund C. Merem John B. Namwamba Olipa S. Mwakimi Tomas Ayala-Silva Diana B. Frimpong Zhu h. Ning abena B. as.re-ans.h Jacob B. Annan Judith Oppong Priscilla M. Loh Faustina Owusu Valentine Jeruto Brilliant M. Petja Ronald Okwemba Joyce McClendon-Peralta Caroline O. Akinrinwoye hermeshia J. Mosby Department of Urban Forestry and Natural resources Southern University and A&M College Baton Rouge Louisiana USA Department of Urban and regional Planning Jackson State University Jackson Mississippi USA Institute of resource Assessment University of Dares Salam Dares Salam Tanzania USDA-ARS Tropical Agriculture research Station Mayaguez Puerto Rico USA Water research Commission (WRC) Private Bag X03 Gezina South Africa

This study employs Landsat-8 Operational Land Imager (OLI) thermal infrared satellite data to compare land surface temperature of two cities in Ghana: Accra and Kumasi. These cities have human populations above 2 million and the corresponding anthropogenic impact on their environments significantly. Images were acquired with minimum cloud cover (h dry and rainy seasons between December to August. Image preprocessing and rectification using ArcGIS 10.8 software were used. The shapefiles of Accra and Kumasi were used to extract from the full scenes to subset the study area. Thermal band data numbers were converted to Top of Atmospheric Spectral Radiance using radiance rescaling factors. To determine the density of green on a patch of land, normalized difference vegetation index (NDVI) was calculated by using red and near-infrared bands i.e. Band 4 and Band 5. Land surface emissivity (LSE) was also calculated to determine the efficiency of transmitting thermal energy across the surface into the atmosphere. Results of the study show variation of temperatures between different locations in two urban areas. The study found Accra to have experienced higher and lower dry season and wet season temperatures, respectively. The temperature ranges corresponding to the dry and wet seasons were found to be 21.0985

Bioenergy Crops as a Promising Alternative to Fossil Fuels in Louisiana: A Geographic Information System (GIS) Perspective

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Journal of Sustainable Bioenergy Systems 2022年第4期12卷 57-81页

作者： Yaw A. Twumasi Zhu h. Ning John B. Namwamba abena B. as.re-ans.h Edmund C. Merem harriet B. Yeboah Judith Oppong Matilda Anokye Diana B. Frimpong Priscilla M. Loh Julia Atayi rechael N. D. Armah Caroline Y. Apraku Opeyemi I. Oladigbolu Cynthia C. Ogbu Leah W. Njeri Joyce McClendon-Peralta Department of Urban Forestry and Natural resources Southern University and A&M College Baton Rouge USA Department of Urban and regional Planning Jackson State University Jackson USA Department of Geography and Tourism Studies Brock University St. Catharines Canada

Rising greenhouse gas emissions are causing climate change, and the world’s focus has shifted to the need to reduce our reliance on fossil fuels. There has been a rise in the published literature on the utilization of crops for bioenergy production in Louisiana. however, very few scholarly documents have used Geographic Information Systems (GIS) to map the distribution of potential bioenergy crops in Louisiana. This study seeks to fill the void by evaluating the potential of bioenergy crops in Louisiana for energy production using GIS. Given this objective, the agricultural census data for 1999, 2009, 2019, and 2020 obtained from the U.S. Department of Agriculture were used in the analysis. The quantities of various crops produced in the state were loaded into an attribute table and joined to a shapefile using ArcGIS software. The symbology tool’s graduated option was used to create five maps representing each of the bioenergy crops in Louisiana. The findings of the GIS analysis show that some of the parishes, such as Franklin produced the most bushels of corn (13,795,416), Iberia produced the most tons of sugarcane (1,697,980), East Carroll produced the most bushels of soybean (8,237,991), Tensas harvested the most bales of cotton (80,898) and Avoyelles produced the most bushels of sorghum (630,694). The abundance and availability of crops as raw materials for energy production will translate into lower prices in terms of energy use, making bioenergy crops a promising alternative to fossil fuels. In addition, gasoline price data from 1993-2022 was obtained from U.S. Energy Information Administration. A regression model for the average annual gasoline price over the years was constructed. The results show that the average annual gasoline price variation with respect to years is statistically significant (p 0.05). This suggests that gasoline prices will generally rise despite a price drop over the years. The paper concludes by outlining policy recommendations in the

关键词： Bioenergy Crops Biomass Fossil Fuel Gasoline Geographic Information Sys-tem (GIS) regression Analysis Louisiana