Search

Korištenje različitih biomasa kao sirovina u biorafinerijama predstavlja dobru alternativu proizvodnji transportnih goriva i drugih vrijednih kemikalija iz fosilnih izvora. U ovom radu je istražena mogućnost rasta plijesni Mucor indicus DSM 2158 na podlogama koje se sastoje od hidrolizata lignocelulozne sirovine - otpadne trave i različitih izvora dušika, te proizvodnja vrijednih metabolita poput etanola i masnih kiselina. Najveća produktivnost procesa obzirom na proizvodnju etanola je ostvarena tijekom uzgoja sa 10 g Lˉ¹ kvaščevog ekstrakta kao izvora dušika, a iznosila je 0,04 g Lˉ¹ hˉ¹. Određen je i lipidni sastav biomase ove plijesni, te je detektirano 24 masne kiseline GC-FID metodom od kojih najveći udio čine oleinska (≈50 %) te palmitinska (≈15 %) kiselina. Udjel lipida izražen na suhu tvar biomase plijesni iznosi 16,9 % (w/w). Otpadne podloge nakon uzgoja M. indicus DSM 2158 su korištene za uzgoj nesumporne ljubičaste bakterije Rhodovulum adriaticum DSM 2781, čija se biomasa može koristiti kao gnojivo, za bioremedijaciju tla ili kao izvor različitih pigmenata. Uzgojem bakterije R. adriaticum DSM 2781 na otpadnoj podlozi u bioreaktoru s miješalom ostvarena je prinos biomase od 2,3 g Lˉ¹ te je postupkom ekstrakcije iz biomase izdvojeno 60 mg g-1 ukupnih pigmenata izraženo na suhu tvar biomase. Using biomass as feedstock in biorefineries represents a good alternative to production of fuels and other value-added chemicals from fossil sources. Cultivations of fungi Mucor indicus DSM 2158 on lignocellulosic feedstock - wheat grass hydrolysate with diffeent nitrogen sources, and production of valuable metabolites such as ethanol and fatty acids was investigated in this research. Highest ethanol productivity (0.04 g Lˉ¹ hˉ¹) was achieved while cultivating the fungus in a medium with 10 g Lˉ¹ of yeast extract. Fatty acid composition in M. indicus biomass was determined using GC-FID method. Total of 24 fatty acids were detected, while oleic and palmitic acid represented about 50 % and 15 % of total fatty acids, respecitvely. Lipid fraction in biomass accounts up to 16.9 % (w/w) of the biomass dry weight. After cultivations of Mucor indicus DSM 2158, waste liquid media were used for cultivations of non-sulphur purple bacteria Rhodovulum adriaticum DSM 2781. The biomass of R. adriaticum DSM 2781 can be used as a fertilizer, for soil bioremediation or as a source of pigments. Cultivation of Rhodovulum adriaticum DSM 2781 in a stirred-tank bioreactor yields 2.3 g Lˉ¹ of biomass. From obtained biomass using extraction method 60 mg g-1 total pigments were produced.

Sve veće potrebe za ekološki i ekonmski održivim proizvodnjama dovele su do razvoja biorafinerija i iskorištavanja obnovljivih izvora energije. Biorafinerija je integrativni i višenamjenski koncept koji koristi lignoceluloznu biomasu za održivu proizvodnju, a uključuje selektivnu transformaciju različitih molekula biomase u biokemikalije, biopolimere, biogoriva i druge spojeve. Cilj ovog rada je ispitati utjecaj različitih tipova bioreaktora na rast plijesni Mucor indicus čija biomasa je bogata masnim kiselinama, dok je proizvod asimilacije šećera iz hranjive podloge ksilitol. Uzgojem plijesni Mucor indicus u biorekatoru s mješalom proizvelo se 6,634393 g/L ksilitola, 3,5414 g/L suhe tvari biomase koja je sadržavala 72,5 % nezasićenih masnih kiselina s najvećim udjelom cis-9 oktadekanoična kiseline u postotku od 50,5 %. Kad se plijesan Mucor indicus uzgajala u babotirajućem bioreaktoru dobilo se 0,750836 g/L ksilitola, 4,624 g/L biomase koja je sadržavala 82,4 % nezasićenih masnih kiselina s najvećim udjelom cis-9-oktadekanoične kiseline u postotku od 47,11 %. Kako bi se dodatno smanjila količina otpada, na iskorištenim podlogama iz uzgoja plijesni proveo se uzgoj fototrofnih ljubičastih nesumpornih bakterija u svrhu iscrpljivanja izvora ugljika i dušika iz navedenih podloga. Tijekom uzgoja ljubičastih nesumpornih bakterija pratio se utjecaj različitih izvora svjetlosti, na rast i sintezu bakterioklorofila a. The growing need for both ecologically and economically sustainable production systems has brought to the development of biorefineries and the use of renewable raw materials. A biorefinery is an integrative and multipurpose concept that uses lignocellulosic biomass for sustainable production which includes a selective transformation of different biomass molecules into biochemicals, biopolymers, biofuel, and other components. The purpose of this thesis is to examine the influence of different bioreactor types on Mucor indicus growth, whose biomass is rich with fatty acids whereas the product of sugar assimilation is xylitol. Cultivating Mucor indicus in a stirred-tank bioreactor resulted in the production of 6,634393 g/L of xylitol and 3,5414 g/L of dry biomass that consisted of 72,5 % non-saturated fatty acids with cis-9 octadecanoic acid having the largest ratio of 50,5 %. When the Mucor indicus was cultivated in a sparged tank bioreactor, the amount of xylitol and biomass produced was 0,750836 g/L and 4,624 g/L respectively, whereas the dry biomass consisted of 82,4 % of non-saturated fatty acids with the largest ratio of cis-9-octadecanoic acid of 47,11 %. To reduce the total amount of waste from the cultivations and to use the carbon and nitrogen left-overs, the fermented broth was used for the cultivation of phototrophic purple non-sulfur bacteria, during which the influence of different light sources on the growth and bacteriochlorophyll a synthesis was examined.

Ksilitol je industrijski važan poliol koji se zbog svojih svojstava koristi kao zamjena za šećer te se dodaje u različite proizvode. U ovom radu proveden je šaržni uzgoj plijesni Mucor indicus DSM 2185 na hidrolizatu otpadne trave s ciljem proizvodnje ksilitola. Nakon provedenog procesa proizvodnje ksilitola centrifugiranjem su izdvojeni biomasa i supernatant. Efikasnost procesa proizvodnje ksilitola iznosila je 42,16 % uz prinos ksilitola od 14,57 g Lˉ¹. Supernatant je korišten za izdvajanje ksilitola kristalizacijom. Maksimalni prinos procesa kristalizacije iznosio je oko 30%. Biomasa ove plijesni predstavlja važan nusproizvod, te je korištena za izolaciju hitina i hitozana. Nakon provedenog postupka izolacije hitina i hitozana, iz biomase plijesni dobiveno je 20,56% hitina te 9,90% hitozana određeno na suhu tvar. Dodatno, određen je i sastav masnih kiselina ove oleaginozne plijesni. Ukupni udio lipida u biomasi plijesni iznosi svega 5,90 % izraženo na suhu tvar, te je plinskom kromatografijom identificirano i kvantificirano 13 estera masnih kiselina, od kojih najveći udio imaju oleinska (C18:1 cis9), linolenska (C18:2 cis 9,12) i γ-linolenska kiselina (C18:3 cis 6,9,12). Xylitol is an industrially important polyol which, due to its properties, is used as a substitute for sucrose and is added to various products. In this paper, batch cultivation of mold Mucor indicus DSM 2185, with the aim of xylitol production, on waste grass hydrolyzate was performed. After the xylitol production process, biomass and supernatant were separated by centrifugation. The efficiency of the xylitol production process was 42,16% with a xylitol yield of 14,57 g Lˉ¹. The supernatant was used to separate the xylitol by crystallization. The maximum yield of the crystallization process was about 30%. The biomass of this mold is an important by-product, and, therefore, has been used to isolate chitin and chitosan. After the isolation procedure of chitin and chitosan, 20.56% of chitin and 9.90% of chitosan was isolated from biomass. Additionally, the fatty acid composition of this oleaginous mold was determined. The total lipid content in biomass was only 5.90%. Gas chromatographic method was used for identification and quantification of 13 fatty acid esters, from which oleic (C18: 1 cis9), linolenic (C18: 2 cis 9, 12) and γ-linolenic acid (C18: 3 cis 6,9,12) have highest concentration.

Lignocelulozne sirovine poput kukuruznih oklasaka najčešće ostaju neiskorištene, a jeftina su sirovina za proizvodnju biokemikalija kao što je bioetanol. Glavni problem upotrebe takvih sirovina u različitim procesima je potreba provođenja postupaka predobrade i hidrolize koji u konačnici poskupljuju ukupni proces proizvodnje. U ovom radu provedena je enzimska hidroliza (pri 50 °C; pH 4,8) kiselinski predobrađenih kukuruznih oklasaka (s 10-40 g L-1 sirovine) pomoću enzima Viscozyme L i Cellulase, enzyme blend (1-20 % vol vol-1). Stupanj hidrolize od 85 % postignut je kombinacijom 2 % vol vol-1 Viscozyme L i 5 % Cellulase, enzyme blend. Nakon optimizacije enzimske hidrolize, dobiveni hidrolizat korišten je za uzgoj plijesni Mucor indicus te proizvodnju etanola u HRCB-u i barbotirajućem bioreaktoru. Uspješnija proizvodnja bioetanola postignuta je u barbotirajućem bioreaktoru uz ostvarene pokazatelje uspješnosti procesa: YP/S = 0,46 g g-1; Pr = 0,40 g L-1 h-1; E = 90,20 %. Lignocellulosic raw materials like corn cobs are mostly left unused, but they are a cheap raw material for the production of biochemicals, e.g. bioethanol. The main problem with the utilization of such raw materials in different bioprocesses lies in the necessary pretretments and hydrolysis that ultimately increase the cost of the overall production process. In this work, enzymatic hydrolysis (at 50 °C; pH 4.8) of dilute acid pretreated corn cobs (with 10-40 g L-1) was performed using Viscozyme L and Cellulase, enzyme blend (1-20 % vol vol-1). A hydrolysis rate of 85 % was obtained with the combination of 2 % vol vol-1 Viscozyme L and 5 % vol vol-1 Cellulase, enzyme blend. After the optimization of enzymatic hydrolysis, the resulting hydrolysate was used for the cultivation of Mucor indicus and the production of ethanol in HRCB and bubbling bioreactor. Comparing the two production processes, bioethanol production in the bubbling bioreactor was more successful, with the following obtained bioprocess efficiency parameters: YP/S = 0.46 g g-1; Pr = 0.40 g L-1 h-1; E = 90.20 %.

U ovom radu proveden je proces simultane enzimske saharifikacije i fermentacije ispranog i usitnjenog čvrstog dijela zaostalog nakon kiselinske predobrade kukuruznih oklasaka. U cilju uspješne provedbe procesa istražen je utjecaj dva različita enzimska pripravka (Cellulase Blend-a i Viscozyme-a) u koncentraciji od 10 % (vol/vol) te njihove kombinacije, 2 % (vol/vol) Cellulase Blend i 5 % (vol/vol) Viscozyme na iskorištenje hidrolize glukana, ksilana i ukupnih ugljikohidrata korištene sirovine. Najviši stupanj hidrolize glukana (100 %) i ukupnih ugljikohidrata (89,90 %) dobiven je uz 10 % (vol/vol) Cellulase Blend na 40 °C u hranjivoj podlozi, a ksilana (93,51 %) uz 10 % (vol/vol) Viscozyme pri 40 °C u puferu. Kako bi se ispitao utjecaj temperature i podloge na uspješnost procesa proizvodnje bioetanola pomoću plijesni M. indicus proveden je aerobni uzgoj u Erlenmayer tikvicama tehnikom simultane enzimske saharifikacije i fermentacije na 30 i 40 °C u puferu i podlozi. Najveća uspješnost procesa proizvodnje etanola zabilježena je kod uzgoja u podlozi uz dodatak 4 % (vol/vol) Cellulase Blend-a pri 30 °C, a produktivnost je iznosila 0,0939 g L-1 h-1. U istim uvjetima te uz dodatak istog enzimskog pripravka koncentracije 4 % (vol/vol) proveden je uzgoj M. indicus u bioreaktoru s miješalom, a produktivnost je nakon 22 h uzgoja iznosila 0,1432 g L-1 h-1. Nakon uzgoja provedena je izolacija glukozamina. In this paper, the procedure of simultaneous saccharification and fermentation of washed and shredded solid residues after dilute acid pretreatment of corn cobs was performed. In order to successfully carry out the process, the effect of two different enzyme blends (Cellulase Blend and Viscozyme at a concentrations of 10 % (vol/vol)) and their combination, 2 % (vol/vol) Cellulase Blend and 5 % (vol/vol) Viscozyme) on the efficiency of hydrolysis of glucan, xylan and total carbohydrates of the raw material used was investigated. The highest degree of hydrolysis of glucan (100 %) and total carbohydrates (89.90 %) was obtained with a 10 % (vol/vol) Cellulase Blend at 40 °C in the matrix which simulates the broth, and xylan (93.51 %) with 10 % (vol/vol) Viscozyme at 40 °C in acetate buffer. In order to examine the influence of temperature and media on the success of the bioethanol production process by M. indicus, aerobic cultivation was performed in Erlenmayer flasks by the technique of simultaneous enzymatic saccharification and fermentation at 30 and 40 °C in two different broths. The highest bioprocess productivity of 0.0939 g L-1 h-1 was observed in broth with the addition of 4 % (vol/vol) Cellulase Blend at 30 °C. M. indicus was grown in a stirred tank bioreactor under the same conditions and with the addition of the same enzyme blend at a concentration of 4 % (vol/vol). After 22 hours of cultivation the productivity reached value of 0.1432 g L-1 h-1. The isolation of glucosamine was performed after cultivation.