1,295 research outputs found

    A multi-scale analysis of biofuel-related land acquisitions in Tanzania : with focus on Sweden as an investor

    Get PDF
    Spurred on by pressure to find sustainable energy production alternatives to fossil fuels, many industries have been acquiring land in order to plant crops for biofuel production. In Tanzania, biofuel development is in an early stage, and over the last decade, several foreign actors have tried to start up biofuel projects in the country (without success). Land acquisitions are seen by many as a foreign investment and a way for developed countries to transfer resources to the Global South. The land deals have not yet been for the benefit of the local population, and have caused long-term negative social and environmental impacts. The overall purpose of this thesis is to clarify the structure of the land acquisition system in Tanzania especially in relation to biofuels over a 10-year time horizon, with Sweden’s role in the system emphasized. Since the land acquisition system is complex, it is important to be able to disentangle this complexity in a structured way across local, national, and global scales in order to shed light on what is driving the investments, and what the positive and negative outcomes are. In order to accomplish this task, a modified multi-level Drivers-Pressures-State-Impact-Response (DPSIR) scheme is applied to information gathered about the land transaction system from field visits, and literature. DPSIR is a causal framework that allows the representation of environment-society relationships to be recast in a tractable format for helping with policy decisions. Each letter of the DPSIR scheme represents an element of the land transaction system at a global, national, and local scale, and in this case is used to tease out cross-scale relationships between system aspects. The scales are linked together through the story of EcoEnergy, a Swedish biofuel company that is acquiring land in Tanzania. Results show that global drivers ultimately lie behind the phenomenon of large-scale land acquisitions in Tanzania and include increased oil prices, climate change, population growth, and policies promoting biofuels. National drivers include climate mitigation strategies, and social and agricultural developments. Locally, business opportunities are important, amongst others. Global pressures include land cover change, altered rainfall patterns, and the competition between food and fuel crops. They manifest themselves nationally and locally through, deforestation, migration, changes in land tenure (national), as well as household displacement, and water extraction (local). Many biofuel companies in Tanzania are currently not active, because they have gone bankrupt, sold the operation, or have trouble starting the business. This is mainly a consequence of the financial crisis in 2007/2008 that led many banks and investors to withdraw from these rather “insecure” investments. Also, investments that are not currently in progress have continuous impacts on the local community since leases normally last for 99 years, thus hindering the small-scale farmer to use the land. National impacts are such as migration, and loss of endemic species and wildlife habitats due to land clearing, but global impacts are not yet apparent. When investments started to increase in the early 2000s, Tanzania did not have proper regulations to control how investors perform, and how to compensate the local population. Tanzania still lacks fully developed regulations for foreign investments, but is trying the investment model “land for equity”. EcoEnergy is the pilot project to develop under this model that might bring more benefits for the government, the investor, and hopefully also for the local community. The new model for investments is an example of a cross-scale interaction between the local and national level, as it has been developed to mitigate local negative impacts. This thesis underscores that the driving forces creating the state of biofuel-related land acquisitions are mainly global, while the impacts are mainly local. This also relates to the tendency of global processes to develop gradually over a long time, while local processes develop more rapidly. Since the phenomenon is fairly new, the global long-term implications are not yet visible. It is therefore necessary to elaborate on the potential long-term impacts from the investments, which can be done by modelling future scenarios of key drivers on all spatial and temporal scales such as population growth, financial changes, climate change, and future demand for alternative fuels

    A Cultured and Happy Family: A Minor Field Study on the Correlation Between the Implementation of the Vietnamese Family Planning Policy and the Prevalence of Son Preference

    Get PDF
    Vietnam har sedan den socialistiska revolutionen pÄ mitten av 1900-tlaet arbetat aktivt för jÀmstÀlldhet mellan kvinnor och mÀn. Sedan 1982 Àr Vietnam part till Konventionen om avskaffande av all slags diskriminering av kvinnor (CEDAW). Patriarkala strukturer influerade av konfucianismen lever dock vidare, och det vietnamesiska samhÀllet Àr Àn idag starkt prÀglat av sociala hierarkier mellan könen. SÄdana könsstereotypa strukturer Àr sÀrskilt ihÀrdiga inom familjens domÀn. Sedan 1960-talet har Vietnam implementerat en familjeplaneringspolicy. Denna policy har pÄverkat förutsÀttningarna för det dagliga livet för vietnamesiska familjer, och utgör ett omfattande statligt ingrepp inom individens familje- och privatliv. Denna uppsats utforskar den vietnamesiska familjeplaneringspolitikens effekter pÄ jÀmstÀlldhet mellan kvinnor och mÀn, och utforskar om utformningen av den nuvarande Vietnamesiska familjeplaneringspolicyn Àr förenlig med Vietnams skyldigheter enligt CEDAW. Mer exakt besvaras denna frÄgestÀllning genom en analys av möjliga samband mellan implementeringen av den vietnamesiska familjeplaneringspolicyn och förekomsten av preferens för söner. Att familjer föredrar söner framför döttrar Àr ett utbrett fenomen i Vietnam. Den grundlÀggande orsaken till detta fenomen Àr ett patrilineÀrt strukturerat samhÀlle, i vilket söner vÀrderas högre Àn döttrar. Under de senaste Ären har denna önskan bland familjer att föda en son tagit nya uttryck, och Vietnam upplever för nÀrvarande en ökande obalans i den nationella könsbalansen bland nyfödda. Svaga insatser frÄn staten för att genomdriva förbud mot prenatal könselektion, i kombination med en Äterupplivning av traditionella vÀrden som initierats av staten pÄ 1980-talet, har genererat en regression i arbetet för jÀmstÀlldhet mellan kvinnor och mÀn i Vietnam. Det kvinnoideal som för nÀrvarande propageras av staten förstÀrker de könsstereotyper som ligger bakom de sociala strukturer som genererat preferens för söner. Den nuvarande utvecklingen i implementeringen av den vietnamesiska familjeplaneringspolitiken strider mot Vietnams skyldigheter enligt CEDAW. De grundlÀggande skyldigheter som faststÀlls i artiklarna 1-5 CEDAW stipulerar statens ansvar att bekÀmpa genusstereotypa strukturer och sÀkerstÀlla implementeringen av principen om icke-diskriminering i den nationella rÀttsordningen. Den nuvarande implementeringen av familjeplaneringspolicyn förstÀrker genusstrukturer pÄ bekostnad av kvinnors mÀnskliga rÀttigheter, och ser mellan fingrarna pÄ den utbredda praxis av prenatal könsselektion som utförs inom en vinstdriven vÄrdsektor.The State of Vietnam has worked actively against inequality between women and men since the early days of the socialist revolution in the mid-twentieth century. Vietnam is since 1982 State Party to the Convention on the Elimination of All Forms of Discrimination against Women (CEDAW). However, patriarchal structures influenced by Confucian ideology remain strong in present-day Vietnamese society. Such gender stereotyped structures are especially persistent within the realm of family life. Since the 1960s, Vietnam has implemented a family planning policy. These policies have altered the preconditions of the family life of Vietnamese families, and constitute an extensive State intervention in the ambit of family life and the private life of the individual. This thesis explores the impact and consequences of the Vietnamese family planning policies on equality between women and men, and explores the concurrence between the formulation of the current Vietnamese family planning policy and the State obligations of Vietnam under the CEDAW. More precisely, this question is answered through an analysis of the possible correlation between the implementation of the Vietnamese family planning policy and the prevalence of son preference. Son preference is a widespread phenomenon in Vietnam. The root cause of this phenomenon is a predominant patrifocal kinship structure, highly valuing the birth of sons. In recent years, the desire of families to have a son has taken new expressions, and Vietnam is currently experiencing an increased imbalance in the national Sex Ratio at Birth. This is an alarming development for the status of gender equality in Vietnam. Feeble efforts of the State to enforce prohibitions on prenatal sex selection and inconsistency in the implementation of national legislation prohibiting discrimination against women, in combination with a revitalisation of Vietnamese traditional cultural values initiated by the State in the 1980s, has generated a regression in the efforts for equality between women and men in Vietnam. The ideal femininity currently propagated by the State through the family planning policy and the family planning campaigns revitalises a traditional Vietnamese female ideal, reinforcing the very gender stereotypes underlying the social structures generating preference for sons. The current development in the implementation of the Vietnamese family planning policy is inconsistent with the State obligations of Vietnam under the CEDAW. The core obligations set out in Articles 1-5 CEDAW stipulate a responsibility of the State to combat gendered social structures and ensure the enforceability of provisions of non-discrimination under the domestic legal system. The current implementation of the family planning policy reinforces gendered structures detrimental to the enjoyment of human rights of women, and turns a blind eye to the practices of prenatal sex selection performed by a profit driven health care sector

    From genes to blooms : Diversity in microcystin phenotypes and mcy biosynthesis genes in the cyanobacterium Microcystis

    Get PDF
    Cyanobacterial blooms are increasing in occurrence and frequency world-wide, mainly due to eutrophication and increased water temperatures. In freshwater, Microcystis is one of the most common bloom-forming genera, renowned for producing the toxin microcystin which is harmful to humans and other mammals. The ability of Microcystis strains to produce microcystins is largely due to the presence or absence of genes encoding microcystin biosynthesis (i.e. the mcy gene cluster), and the toxicity of Microcystis blooms is therefore dependent on the presence of toxin producing genotypes in the population. Numerous laboratory studies and field studies have aimed at explaining what environmental factors drive toxic blooms, however, with various results. Moreover, there is limited understanding of what the eco-physiological role of microcystin might be, and what factors influence microcystin concentration in the water. The aims of this thesis were to examine 1) the phenotypic and genotypic composition and variation in Microcystis, with regards to microcystin-production, 2) the association between mcy genotypes and the observed microcystin phenotypes, and 3) what environmental conditions favour microcystin-producing Microcystis during blooms, and are associated to microcystin concentrations in lake systems.In paper I, Microcystis botrys strains were isolated and cultured from a single bloom, and their microcystin-profiles were analysed with mass spectrometry. I could show that the microcystin-producing M. botrys subpopulation contained multiple microcystin-phenotypes, and that the phenotypic diversity varied on a temporal scale. Not only were the proportions of microcystin-producing strains higher during early and late summer, but the microcystin-profiles were more diverse, and the number of microcystin variants produced by individual strains were higher. In paper II, I performed whole genome sequencing of the strains analysed in the first study. Thereby, I could characterise the variation within the mcy gene cluster, encoding for microcystin biosynthesis, and show how the composition of mcy genotypes relates to the observed phenotypes. One main finding was that both microcystin-producing and non-producing strains consist of several genotypes, that either possess the full mcy gene cluster, or partial operons. Based on the results of paper II, in paper III I developed a population-tailored marker for quantitative polymerase chain reaction (qPCR) targeting the mcyJ gene in the mcy gene cluster. I was thereby able to detect and quantify the abundance of toxigenic cells in natural populations of Microcystis spp., sampled from two Swedish lakes. I also sampled and analysed several environmental variables to determine which factors favour toxigenic vs non- toxigenic strains. The results confirmed the temporal succession of microcystin- producing and non-producing phenotypes observed in paper I. I could also show that toxigenic Microcystis spp. were associated with high concentrations of inorganic nitrogen, whereas microcystin concentrations were associated with soluble reactive phosphorus.To conclude, my results show that there is inherent phenotypic and genotypic variation in Microcystis: the studied subpopulations contain multiple microcystin- phenotypes, as well as mcy genotypes. The presence of several mcy genotypes, found in both microcystin-producing and non-producing phenotypes, indicate that microcystin production might not be attributed to the presence or absence of mcy genes alone. Furthermore, toxic Microcystis blooms are likely driven by nutrient availability in the studied systems, which confirms that management strategies for bloom mitigation should focus on both phosphorus and nitrogen reduction

    slipp Ängest - anvÀnd kondom. En fokusgruppstudie om nÄgra gymnasieungdomars attityder kring sexuellt beteende

    Get PDF
    Syftet med vĂ„r undersökning Ă€r att undersöka nĂ„gra gymnasieungdomars kunskap och uppfattningar betrĂ€ffande sexuellt beteende samt hur ungdomarna menar att man omsĂ€tter dessa i praktiken. Vi har anvĂ€nt oss av följande frĂ„gestĂ€llningar för att nĂ€rma oss vĂ„rt syfte: ‱ Vad har ungdomarna för kunskap och instĂ€llning till könssjukdomar, frĂ€mst klamydia? ‱ Vad anser ungdomar om anvĂ€ndandet av preventivmedel i allmĂ€nhet och kondom i synnerhet? ‱ PĂ„ vems ansvar och under vilka omstĂ€ndigheter sker och förhandlas sĂ€krare sex? ‱ Vilken instĂ€llning har ungdomar vad gĂ€ller tillfĂ€lliga sexuella förbindelser och antal partners? ‱ TĂ€nker killar (pojkar) och tjejer (flickor) lika om detta eller finns det könsskillnader i deras uppfattningar och beteende? För att kunna fördjupa vĂ„r studie har vi valt att anvĂ€nda oss av de tvĂ„ datainsamlingsmetoderna fokusgrupper och vinjettmetoden. AnvĂ€ndandet fokusgrupper handlade om att vi ansĂ„g att denna metod skulle hjĂ€lpa oss att fĂ„ en mer övergripande bild av Ă€mnet. Den hjĂ€lper oss att se processer och diskussioner i en grupp, vilket ocksĂ„ var det vi ville koncentrera oss pĂ„. Vinjettmetoden valde vi för att ungdomarna skulle fĂ„ prata om fiktiva personer och hĂ€ndelser i stĂ€llet för att behöva prata om sig sjĂ€lva. Resultatet av vĂ„r undersökning visar att ungdomar oroar sig i högre utstrĂ€ckning för en graviditet Ă€n att fĂ„ klamydia. Klamydia Ă€r sĂ„ pass lĂ€tt att bota att man inte tycker det Ă€r mycket vĂ€rre Ă€n en förkylning. Ungdomarna anser att kondom Ă€r det sĂ€kraste och bĂ€sta preventivmedlet, samtidigt som det ocksĂ„ Ă€r det mest besvĂ€rliga. Det kan vara pinsamt att ta upp att man vill anvĂ€nda kondom, bland annat för att man Ă€r rĂ€dd att förstöra stĂ€mningen. Att ha sex utan att ha ett förhĂ„llande Ă€r nĂ„got som Ă€r ganska vanligt hos ungdomar. Samtidigt som det Ă€r accepterat Ă€r det till viss del tabu och resulterar ibland i ifrĂ„gasĂ€ttande hos omgivningen. Skillnaden mellan att vara KK och tillsammans Ă€r för ungdomarna svĂ„rt att beskriva. I teorin Ă€r det okej att ha haft sex med mĂ„nga, men i praktiken kan det medföra att dessa personer ses som en ”hora” eller en ”player”. Att en tjej har haft sex med mĂ„nga Ă€r mer negativt Ă€n om en kille har det. En bedömning av risk, hur sĂ€kert, eller osĂ€kert, det Ă€r att ha sex med personen i frĂ„ga, görs ofta nĂ€r man trĂ€ffar en ny partner. Har man haft sex med fĂ„ personer, och inom förhĂ„llanden, ses detta som seriöst. Seriösa personer bedöms som sĂ€krare att ha sex med Ă€n oseriösa. Att ha kĂ€nslor för en person pĂ„verkar ocksĂ„ riskbedömningen. Ungdomarna tycker det Ă€r svĂ„rare att tro att en person man kĂ€nner eller Ă€r kĂ€r i har en könssjukdom

    Ett mÄngkulturellt dilemma ­ om pedagogers syn pÄ en mÄngkulturell undervisning i olika miljöer

    Get PDF
    __________________________________________________________________________ Att arbeta mĂ„ngkulturellt Ă€r nĂ„got vi finner viktigt inom skolan. LĂ€roplanen nĂ€mner faktorer av mĂ„ngkulturell prĂ€gel som skolans grundlĂ€ggande vĂ€rden. VĂ„ra erfarenheter sĂ€ger oss att detta vĂ€rde inte efterlevs. Vad kan det bero pĂ„? VĂ„rt syfte Ă€r att ta reda pĂ„ hur pedagoger uppfattar mĂ„ngkultur och hur deras mĂ„ngkulturella undervisning ser ut. Litteraturstudier har visat pĂ„ att mĂ„ngkulturell undervisning i huvudsak bedrivs i omrĂ„den av stor kulturell mĂ„ngfald. Är det beroende pĂ„ skolans kulturella samhĂ€llskontext en mĂ„ngkulturell undervisning tillĂ€mpas? UtifrĂ„n dessa litteraturstudier vi beaktar har vi utfört intervjuer och observationer pĂ„ tvĂ„ skolor: en skola i ett i majoritet svenskt omrĂ„de i Sverige och en svensk skola i Thailand med i majoritet svenska elever. Intervjuerna har visat hur pedagoger ser pĂ„ begreppen och hur de arbetar idag samt hur de tror deras mĂ„ngkulturella undervisning skulle se ut i ett annat omrĂ„de. Resultatet innefattar pedagogernas egen syn pĂ„ mĂ„ngkultur och tar oss vidare till diskussionen dĂ€r vi jĂ€mför intervjuerna med tidigare litteraturstudier. VĂ„ra frĂ„gestĂ€llningar och syfte samt litteratur argumenteras kring och avsaknaden av mĂ„ngkultur i skolan blir ett faktum. Arbetet belyser svĂ„righeten med att arbeta mĂ„ngkulturellt pĂ„ grund av begreppets komplexa definition och pĂ„ grund av samhĂ€llets fortgĂ„ende vi och dom-perspektiv

    Nutrition for weight loss in overweight cats

    Get PDF
    Övervikt och fetma Ă€r ett vanligt problem hos tamkatter. Detta pĂ„verkar hĂ€lsotillstĂ„ndet hos djuret och kan leda till en ökad risk att drabbas av följdsjukdomar samt till en försĂ€mrad livskvalitet. Det Ă€r dĂ€rför essentiellt att övervikt och fetma behandlas. För att fĂ„ en sĂ€ker viktnedgĂ„ng Ă€r det viktigt att anvĂ€nda sig av en lĂ€mplig diet. Det finns olika nutritionella principer för viktminskning hos katt. Syftet med denna studie var att gĂ„ igenom litteraturen för tre av dem samt undersöka om och hur dessa typer av viktminskningsfoder anvĂ€nds kliniskt i Sverige. Denna kandidatuppsats bestĂ„r av en sammanstĂ€llande litteraturstudie i kombination med en intervjustudie gjord med en viktminskningsansvarig djurhĂ€lsopersonal respektive en butiksanstĂ€lld pĂ„ tvĂ„ olika djursjukhus i Sverige. De tre viktminskningsfoder som undersöktes i denna studie var traditionellt viktminskningsfoder, metabolt foder samt vĂ„tfoder. Dessa fodertyper hade vart och ett vetenskapliga evidens av olika grad för att ge en framgĂ„ngsrik viktminskning hos överviktiga katter genom olika verkningsmekanismer. Dock Ă€r forskningen inom omrĂ„det generellt sparsam och fler studier behövs som behandlar nutrition hos överviktiga katter. Ett traditionellt viktminskningsfoder har fokuserat pĂ„ att minska mĂ€ngden kalorier genom ett lĂ„gt fettinnehĂ„ll och ökat fiber- och/eller proteininnehĂ„ll, vilket bidrar till en lĂ€gre energidensitet. Studier visade att genom ett högt proteininnehĂ„ll i viktminskningsfoder kunde energiutgiften hos överviktiga katter öka om fodret gavs med energirestriktion. Foder med högt proteininnehĂ„ll kunde ges med lĂ€gre energirestriktion jĂ€mfört med foder med lĂ„gt proteininnehĂ„ll. Det ökade Ă€ven förlusten av kroppsfett och frĂ€mjade bevarandet av fettfri massa hos överviktiga katter som gick ner i vikt. Till skillnad frĂ„n traditionellt viktminskningsfoder innehĂ„ller metabolt foder tillsatser av vissa nĂ€ringsĂ€mnen, bland annat L-karnitin, i syfte att öka fettförbrĂ€nningen. Studier visade pĂ„ en viktminskning med gott resultat, oavsett om fodret gavs med eller utan energirestriktion, hos överviktiga katter som Ă„t ett metabolt foder innehĂ„llande komponenter som ökade fettförbrĂ€nningen. Vissa av dessa studier kan dock möjligen anses jĂ€viga, respektive var icke publicerade. VĂ„tfoder har ett lĂ„gt innehĂ„ll av kalorier tack vare den mĂ€ngd vĂ€tska som finns i fodret och kan ges med eller utan energirestriktion. Vatten som ingrediens i ett foder bidrar till att kaloridensiteten minskas och fodret vĂ€ger mer utan att mer energi har tillsatts. Flera studier visade att en diet bestĂ„ende av vĂ„tfoder eller en kombination av vĂ„t- och torrfoder ledde till framgĂ„ngsrik viktminskning, delvis genom en ökad mĂ€ttnadskĂ€nsla. I intervjustudien genomfördes tvĂ„ intervjuer. I intervjuerna framkom det att dessa tre typer av viktminskningsfoder anvĂ€nds pĂ„ djursjukhus i Sverige och ger en viktminskning med gott resultat. Den ena respondenten upplevde bĂ€ttre viktminskningsresultat vid anvĂ€ndning av traditionellt viktminskningsfoder jĂ€mfört med metabolt foder och vĂ„tfoder. Den andra respondenten upplevde inte nĂ„gon skillnad i resultat mellan de tre fodren. Intervjustudien fĂ„r ses som exempel frĂ„n klinisk verksamhet och Ă€r ej representerbar för alla djursdjukhus i Sverige. För att kunna dra slutsatser om alla djursjukhus i Sverige behövs ett större urval. Det finns för- och nackdelar med de olika fodren, men alla har vetenskapliga evidens och bidrar till viktminskning med gott resultat. Det gĂ„r ej att konkludera vilken nutritionell viktminskningsprincip som fungerar bĂ€st för alla katter utan val av viktminskningsfoder fĂ„r ses som individuellt och anpassas efter djurĂ€garen och katten för att fĂ„ ett lyckat viktminskningsresultat.It is common that pet cats are overweight or obese which may lead to a decreased quality of life and an increased risk of secondary diseases. Therefore, it is essential that overweight and obesity is treated. It is important to use a suitable diet when losing weight to ensure a safe and healthy weight loss. Different nutritional regimens can be used in feline weight-loss management. The aim of this study was to evaluate three different nutritional regimens and investigate how those weight-loss diets were used in clinical environments in Sweden. This bachelor’s thesis is a combined literatureand interview study, where an animal healthcare professional and a store employee at two animal hospitals in Sweden were interviewed. This study reviewed three different weight-loss diets; traditional weight-loss diets, metabolic diets and wet or canned food. The different diets all contributed to successful weight loss through separate mechanisms and withheld scientific evidence in varying degrees for its effectiveness. Research on nutrition for feline weight loss is scarce and additional research is required. A traditional weight-loss diet aims for a lower energy density, by reducing fat content while increasing fiber- or protein content. Studies showed that by increasing proteins in a diet, the energy expenditure increased in overweight cats when the diet was given with an energy restriction. Diets with high protein levels could be given with a lower energy restriction compared to diets low in proteins. Furthermore, a diet with high levels of protein increased the loss of adipose tissue in overweight cats while lean body mass was preserved. In contrast to traditional weight-loss diets, metabolic diets consist of nutritional additives, such as L-carnitine, that aim to increase fat oxidation. Studies showed successful weight loss with those diets, regardless if the diet was given with or without energy restriction. However, some of those studies may be considered biased or were unpublished. Wet or canned food has, due to the amount of added water, a low-calorie content and can be given with or without energy restriction. Water lowers the calorie density and the food increases in weight without increasing in energy content. Several studies showed that both wet-food diets and combined wet- and dry-food diets led to successful weight loss, partly because of an increased satiation. Two interviews were conducted in the interview study. The interviews revealed that these three types of weight loss diets are used in animal hospitals in Sweden and give a weight loss with good results. One respondent experienced better weight loss results when using a traditional weight loss diet compared to metabolic diet and wet food. The second respondent did not experience any difference in results between the three diets. The interview study can be seen as an example from clinical activities and is not representative of all animal hospitals in Sweden. In order to be able to draw conclusions about all animal hospitals in Sweden, a larger selection is needed. The different diets regimens come with both pros and cons but had all scientific evidence and successfully contribute to weight loss. It is not possible to conclude which nutritional weight-loss regimen that is the best for all cats, and the choice of a weight-loss diet should be seen as an individual decision that should be adapted to the owner and the cat to achieve a successful weight loss

    Fermentation performance and physiology of two strains of Saccharomyces cerevisiae during growth in high gravity spruce hydrolysate and spent sulphite liquor

    Get PDF
    Background: Lignocellulosic materials are a diverse group of substrates that are generally scarce in nutrients, which compromises the tolerance and fermentation performance of the fermenting organism. The problem is exacerbated by harsh pre-treatment, which introduces sugars and substances inhibitory to yeast metabolism. This study compares the fermentation behaviours of two yeast strains using different types of lignocellulosic substrates; high gravity dilute acid spruce hydrolysate (SH) and spent sulphite liquor (SSL), in the absence and presence of yeast extract. To this end, the fermentation performance, energy status and fermentation capacity of the strains were measured under different growth conditions. Results: Nutrient supplementation with yeast extract increased sugar uptake, cell growth and ethanol production in all tested fermentation conditions, but had little or no effect on the energy status, irrespective of media. Nutrient-supplemented medium enhanced the fermentation capacity of harvested cells, indicating that cell viability and reusability was increased by nutrient addition. Conclusions: Although both substrates belong to the lignocellulosic spruce hydrolysates, their differences offer specific challenges and the overall yields and productivities largely depend on choice of fermenting strain

    Biocompatible Polymer Nanoparticles for Intra-cellular Applications

    Get PDF
    Polymeric styrene microspheres have a great potential at the interface of chemistry and biology. The progress of the synthetic development of multifunctional microspheres and their use as delivery agents of different biomolecules into cells is discussed. Their multifunctional properties open a wide range of applications from intracellular real-time sensors, to the use of microspheres as catalysts performing exogenous chemistry within cells
    • 

    corecore