Potential of the microalgae chlorella sorokiniana for carbon capture from winery fermentations and wastewater bioremediation
| dc.contributor.advisor | Rossouw, Debra | en_ZA |
| dc.contributor.advisor | Bauer, Florian | en_ZA |
| dc.contributor.advisor | Naidoo-Blassoples, Rene K. | en_ZA |
| dc.contributor.author | McMurtry, Sarah K. | en_ZA |
| dc.contributor.other | Stellenbosch University. Faculty of Agrisciences. Dept. of Viticulture and Oenology. | en_ZA |
| dc.date.accessioned | 2022-04-29T09:04:11Z | |
| dc.date.available | 2022-04-29T09:04:11Z | |
| dc.date.issued | 2022-03 | |
| dc.description | Thesis (MScAgric)--Stellenbosch University, 2022. | |
| dc.description.abstract | With rises in global greenhouse gases, efforts to reduce emissions have become increasingly urgent. Carbon dioxide (CO2), one of the major greenhouse gases, is a by-product of wine fermentation. The CO2 generated during this process is in a more concentrated form than CO2 derived from most industrial processes, and in principle represents an ideal source to support photosynthetic processes. The development of biological carbon capture systems may therefore allow wine producers to reduce their carbon footprint, contributing to the aim of a carbon neutral winery. Winemaking also produces vast amounts of low-quality wastewater. Currently available wastewater treatments are either costly or have various disadvantages. Consequently, the use of industrial microorganisms including microalgae for wastewater bioremediation has gained increasing interest. Microalgae can grow in, and bioremediate, numerous sources of wastewater, while producing potentially valuable biomass using CO2 as a carbon source. Coupling carbon capture from wine fermentations with the bioremediation of winery wastewater therefore shows great potential. Similar processes have already been studied in other industries such as the carpet mill industry, livestock industry and some food industries, but there is only very limited data for wine-related applications. Winery wastewater certainly presents a particular challenge because of its seasonality and rapidly changing nature. This inconsistent nature of the wastewater reduces microalgae growth and leads to inefficient carbon capture and biomass production. To alleviate this problem, previous work in our laboratory has investigated co-cultures of winery wastewater-isolated strains of the yeast Saccharomyces cerevisiae and the microalgae Chlorella sorokiniana. Such co-cultures are indeed considered more resilient than single species systems. These strains were furthermore co-evolved in order to strengthen co-culture growth. The purpose of this work was to understand and optimise this system to improve microalgae carbon capture and wastewater bioremediation. The experimental work focused on optimising growth conditions for carbon capture in a laboratory, small-scale synthetic winery environment, as well as on monitoring microalgae and yeast growth in winery wastewater. The data suggest that the system investigated here is able to generate microalgae biomass using sustainable methods, and relevant insights regarding the ability of C. sorokiniana to grow in, and to bioremediate, winery wastewater were generated. Further optimisation is however required to maintain microalgae and yeast growth for longer periods and generate additional microalgae biomass. | en_ZA |
| dc.description.abstract | Met stygingende globale kweekhuisgasse, het pogings om emissies te verminder toenemend dringend geword. Koolstofdioksied (CO2), een van die belangrikste kweekhuisgasse, is 'n byproduk van wynfermentasie. Die CO2 wat tydens hierdie proses gegenereer word, is in 'n meer gekonsentreerde vorm as CO2 afkomstig van die meeste industriële prosesse, en verteenwoordig in beginsel 'n ideale bron om fotosintetiese prosesse te ondersteun. Die ontwikkeling van biologiese koolstofopvangstelsels kan wynprodusente dus toelaat om hul koolstofvoetspoor te verklein. Wynbereiding lei ook tot die produksie van groot hoeveelhede lae-gehalte afvalwater. Bestaande afvalwaterbehandelings is óf duur óf het verskeie nadele. Gevolglik het die gebruik van industriële mikroörganismes, insluitend mikro-alge vir bioremediëring van afvalwater, toenemende belangstelling gekry. Mikro-alge kan groei in talle bronne van afvalwater en dit sodoende bioremediëer. Die koppeling van koolstofopvang afkomstig van wynfermentasies met die bioremediëring van kelder afvalwater toon dus groot potensiaal. Soortgelyke prosesse is reeds in sommige voedselbedrywe bestudeer, maar daar is slegs beperkte data vir wynverwante toepassings. Wyn fermentasie afvalwater bied beslis 'n besondere uitdaging vanweë die seisoenaliteit en vinnig veranderende aard daarvan. Hierdie wisselvallige aard van die afvalwater kan ʼn negatiewe impak op die groei van mikro-alge hê en lei tot ondoeltreffende biomassaproduksie. Om hierdie probleem aan te spreek, het vorige navorsing ko-kulture van kelder afvalwater-geïsoleerde stamme van die gis Saccharomyces cerevisiae en die mikro-alge Chlorella sorokiniana ondersoek. Ko-kulture van verskillende spesies mikroörganismes kan beskou word as meer weerstandbiedend en stabiel in uitdagende groei omstandighede as enkelspesiesisteme. Hierdie stamme is verder saam oor opeenvolgende generasies aan gerigte evolusie blootsgestel om ko-kultuurgroei te versterk. Die uiteindelike doelwit van hierdie navorsing was om die mikrobiese stelsel beter te verstaan en te optimaliseer om mikro-alge se koolstofopvang en bioremediëring van afvalwater te verbeter. Die eksperimentele werk het gefokus op die optimalisering van groeitoestande van beide die gis en mikro-alge vir koolstofopvang in 'n kleinskaalse sintetiese wynkelderomgewing, asook die bepaling van mikroalge en gisgroei in wynkelder afvalwater. Die data dui daarop dat die stelsel wat hier ondersoek is in staat is om mikro-alge biomassa te genereer deur gebruik te maak van volhoubare metodes, en relevante insigte rakende die vermoë van C. sorokiniana om te groei in, en om kelderafvalwater te bioremediëer, is gegenereer. | en_ZA |
| dc.description.version | Masters | en_ZA |
| dc.embargo.terms | 2022-12-31 | |
| dc.format.extent | x, 94 pages : illustrations | en_ZA |
| dc.identifier.uri | http://hdl.handle.net/10019.1/124490 | |
| dc.language.iso | en_ZA | en_ZA |
| dc.subject.lcsh | Chlorella sorokiniana -- Biotechnology | en_ZA |
| dc.subject.lcsh | Microalgae -- Growth | en_ZA |
| dc.subject.lcsh | Carbon dioxide | en_ZA |
| dc.subject.lcsh | Wine and wine making -- Chemistry | en_ZA |
| dc.subject.lcsh | Wine industry -- Waste disposal | en_ZA |
| dc.subject.lcsh | Bioremediation | en_ZA |
| dc.subject.lcsh | Fermentation | en_ZA |
| dc.subject.lcsh | Yeast -- Growth | en_ZA |
| dc.subject.name | UCTD | en_ZA |
| dc.title | Potential of the microalgae chlorella sorokiniana for carbon capture from winery fermentations and wastewater bioremediation | en_ZA |
| dc.type | Thesis | en_ZA |