Yeast Trichosporon cutaneum on deproteinized whey in batch-wise and continued cultivation

Iz sirutke izdvojen kvasac Trichosporon cutaneum uzgaja se šaržno i kontinuirano u deproteiniziranoj sirutki pri pH 4,5-5,0 % temperaturi od 32 °C na tresilici i u laboratorijskom bioreaktoru. Uz dodatak diamonijevog sulfata i kalijevog hidrogen fosfata deproteiniziranoj sirutki kvasac Trichosporon cutaneum se dobro razmnožava pri svim istraživanim koncentracijama laktoze, a najbolja produktivnost procesa postiže se u podlozi sa 4% laktoze.Yeast Trichosporon cutaneum isolated from the whey has been cultivated on the rotary shaker and batch-wise or continuousely in the laboratory bio-reactor. Yeast T. cutaneum growed well at all studied concentrations of lactose in substrate, but the highest productivity of the process was achieved with 0,48-0,60 g DM/g lactose with the specific growth rate of 0,26 h^-1 and the productivity of 1,5 g/dm3/h

Production of single-cell proteins by yeast Kluyveromyces fragilis on whey

Studirana je mogućnost kultivacije kvasca Kluyveromyces fragilis za proizvodnju mikrobnih proteina na sirutci u šaržnom i kontinuiranom postupku pri pH 5,0-5,5 i temperaturi od 40 °C. Ustanovljeno je eksperimentima na tresilici i laboratorijskom fermentoru da se kvasac dobro razmnožava pri odabranim uvjetima okoline, na 2 %-tnoj deproteiniziranoj sirutci s dodatkom diamonijevog sulfata i kalijevog hidrogen fosfata. Pri optimalnim uvjetima okoline postiže se stupanj konverzije laktoze u kvaščevu biomasu od 0,45-0,55 g s. tv. kvasca/g laktoze, specifična brzina rasta do 0,25 sat^-1 i produktivnost procesa do 1,3 g/L/sat. Kada se osnovnom supstratu doda 0,1 % kvaščevog ekstrakta kvasac se razmnožava brže, specifična brzina rasta poraste na 0,35-0,38 sat^-1, a produktivnost procesa dostiže 1,8 g/L/sat. Ukoliko se voda, potrebna za razrjeđenje sirutke, zamijeni melasnom džibrom, postiže se također povećanje brzine rasta kvasca K. fragilis. Specifična brzina rasta bila je do 0,40 sat^-1, a produktivnost procesa od 2,0-2,4 g/L/satThe possibility of cultivation of the yeast Kluyveromyces fragilis for the production of single-cell protein on deproteinated whey was studied. The hatch and the continuous cultivations were performed at pH 5.0-5.5 and the temperature of 40 °C. By experiments on the shaker and in laboratory fermenter it was established that the yeast cells grow well on 2 % deproteinated whey with the addition of ammonium sulphate and potassium hydrogen phosphate. At optimal conditions the biomass yield was 0.45-0.55 g DM/g lactose with the specific growth rate up to 0.25 h^-1 and productivity of 1.3 g/L/h. When 0.1 % of the yeast extract was added to the basic medium the yeast cells were multiplying faster (μ = 0.35-0.38 h^-1) and productivity was up to 1.8 g/L/h. If the water necessary for the dilution of whey was exchanged with molasses slop a. very good effect attained in the cultivation of yeast cells. The specific growth rate was 0.4 h^-1 and productivity up to 2.4 g/L/h

Potential Application of Yeast β-Glucans in Food Industry

Different β-glucans are found in a variety of natural sources such as bacteria, yeast, algae, mushrooms, barley and oat. They have potential use in medicine and pharmacy, food, cosmetic and chemical industries, in veterinary medicine and feed production. The use of different β-glucans in food industry and their main characteristics important for food production are described in this paper. This review focuses on beneficial properties and application of β-glucans isolated from different yeasts, especially those that are considered as waste from brewing industry. Spent brewer’s yeast, a by-product of beer production, could be used as a raw-material for isolation of β-glucan. In spite of the fact that large quantities of brewer’s yeast are used as a feedstuff , certain quantities are still treated as a liquid waste. β-Glucan is one of the compounds that can achieve a greater commercial value than the brewer’s yeast itself and maximize the total profitability of the brewing process. β-Glucan isolated from spent brewer’s yeast possesses properties that are benefi cial for food production. Therefore, the use of spent brewer’s yeast for isolation of β-glucan intended for food industry would represent a payable technological and economical choice for breweries

Production of ethanol and wine from whey

Studirala se mogućnost proizvodnje alkohola i vina iz djelomično deproteinizirane sirutke dodatkom saharoze, te vina uz dodatak saharoze. Fermentacija je provedena u anaerobnim uvjetima uz pomoć kvasca Kluyveromyces fragilis pri pH 4,5-5,5 i 32 °C.Production of ethanol and wine from- whey with the addition of sucrose was studied. Fermentations were performed by yeast Kluyveromyces fragilis at 32 °C and pH 4,5-5,5

Zinc, Copper and Manganese Enrichment in Yeast Saccharomyces cerevisae

The aim of the present work was to study the incorporation of some microelements in the yeast Saccharomyces cerevisiae and its impact on the physiological state of the yeast cells during the alcoholic fermentation. The cultivations were performed on molasses medium in anaerobic (thermostat) and semiaerobic (shaker) conditions, with and without the addition of zinc, copper and manganese sulphate (0.1 g/L of each) at 30 °C and different pH values of the medium (3.5–6.0) for 8 h. The addition of the mentioned salts in molasses medium enhanced the yield of the yeast biomass up to 30 % in semiaerobic conditions, but the ethanol yield was changed very little. On the other hand, in anaerobic conditions the yields of the yeast biomass were increased up to 10 % and alcohol yield up to 20 %. After the fermentations were performed, the concentration of metal ions in yeast cells was determined. Different values were achieved depending on the used growth conditions. The highest amount of Zn ions in dry matter (700 μg/g) was incorporated in the yeast biomass under anaerobic conditions. In contrast, the incorporation of Cu and Mn was preferred in semiaerobic conditions and the highest value of Cu2+ ions in dry matter (1100 μg/g) and Mn2+ in dry matter (300 μg/g) in yeast biomass were obtained. Optimal pH for all ion incorporations was between 4 and 5

The influence of molasses addition on the kinetics of alcoholic fermentation of whey using Kluyveromyces marxianus yeast

U ovom radu praćena je kinetika alkoholne fermentacije pomoću kvasca Kluyveromyces marxianus ZIM 75 na podlogama sastavljenim od sirutke i melase. Fermentacije su provedene u statičkim i semiaerobnim uvjetima na temperaturi 34 °C, a za pripravu podloga korištene su deproteinizirana sirutka i melasa miješane u različitim omjerima tako da je ukupna koncentracija šećera u podlogama bila 5%, 10% i 15%. Provedeni pokusi pokazali su da je podloga koja je sadržavala 10% šećera (saharoza : laktoza = 1:1) optimalna za provođenje fermentacija u statičkim i u semiaerobnim uvjetima. Najbolji prinos etanola u statičkim uvjetima nakon 24 sata fermentacije iznosio je 4,05 % (V/V) dok je u semiaerobnim uvjetima iznosio 4,9 % (V/V). Prirast biomase također je bio bolji u semiaerobnim uvjetima i iznosio je 7,78 g s.tv./L, dok je u statičkim uvjetima prirast biomase iznosio je 3,19 g s.tv./L.Kinetics of alcoholic fermentation by yeast Kluyveromyces marxianus ZIM 75 in various media based on whey and molasses were monitored. The fermentations were performed under static and semiaerobic conditions at 34 °C. Deproteinized whey and molasses were mixed in various proportions to give final sugar mass concentrations of 5%, 10% and 15% in medium. The experiments conducted showed that medium with 10 % of sugar (sucrose:lactose=1:1) is optimal for alcoholic fermentations in static and semiaerobic conditions. The best ethanol yield after 24 hours of fermentation was 4.05 % (V/V) in static conditions and 4.9 % (V/V) in semiaerobic conditions. The biomass yield was 7.78 g d.m./L in semiaerobic conditions and 3.19 g d.m./L in static conditions

Hydrolysis of lactose with -D-galactosidase

U ovom radu su ispitivani uvjeti hidrolize laktoze pomoću enzimskog preparata -D-galaktozidaze, a svrha je - primjena sirutke u fermentativnim procesima s kvascem Saccharomyces cerevisiae za kombiniranu proizvodnju alkohola i prehrambenog kvasca. Enzimska hidroliza je provedena na različitim temperaturama, s različitim koncentracijama laktoze u podlozi i različitim količinama dodanog enzimskog preparata. Rezultati pokazuju da je maksimalni stupanj hidrolize postignut u podlozi koja je sadržavala 5-10 % laktoze s dodatkom 2 g/L enzimskog preparata na temperaturi od 40 ºC.The conditions of lactose hydrolysis with enzyme preparation of D-galactosidase were investigated. The aim of this work was to considered the use of whey in fermentative processes with yeast Saccharomyces cerevisiae. Enzymatic hydrolysis was conducted at different temperatures, with different lactose concentrations in medium and different concentrations of added enzyme. The results show that optimal temperature for hydrolysis was 40°C. The optimal amount of enzyme preparation was 2 gL-1 in lactose medium with 5-10 % lactose

Hydrolysis of lactose with -D-galactosidase

U ovom radu su ispitivani uvjeti hidrolize laktoze pomoću enzimskog preparata -D-galaktozidaze, a svrha je - primjena sirutke u fermentativnim procesima s kvascem Saccharomyces cerevisiae za kombiniranu proizvodnju alkohola i prehrambenog kvasca. Enzimska hidroliza je provedena na različitim temperaturama, s različitim koncentracijama laktoze u podlozi i različitim količinama dodanog enzimskog preparata. Rezultati pokazuju da je maksimalni stupanj hidrolize postignut u podlozi koja je sadržavala 5-10 % laktoze s dodatkom 2 g/L enzimskog preparata na temperaturi od 40 ºC.The conditions of lactose hydrolysis with enzyme preparation of D-galactosidase were investigated. The aim of this work was to considered the use of whey in fermentative processes with yeast Saccharomyces cerevisiae. Enzymatic hydrolysis was conducted at different temperatures, with different lactose concentrations in medium and different concentrations of added enzyme. The results show that optimal temperature for hydrolysis was 40°C. The optimal amount of enzyme preparation was 2 gL-1 in lactose medium with 5-10 % lactose

Biological Effects of Yeast β-Glucans

β-Glucans are glucose polymers that naturally occur in yeasts, molds, algae, mushrooms, bacteria, oats and barley. Immunostimulation is one of the most important properties of β-glucans. They are classified as biological response modifiers and because of their biological activities they can be used in human and veterinary medicine and pharmacy. Additionally, β-glucans show interesting physicochemical properties and therefore could be applied in food and feed production as well as in cosmetic and chemical industries. Immunomodulation by β-glucan, both in vitro and in vivo, inhibits cancer cell growth and metastasis and prevents or reduces bacterial infection. In humans, dietary β-glucan lowers blood cholesterol, improves glucose utilization by body cells and also helps wound healing. β-Glucans work, in part, by stimulating the innate immune mechanism to fight a range of foreign challenges and could be used as an adjuvant, in combination with anti infective or antineoplastic agents, radiotherapy, and a range of topical agents and nutrients. The structure of β-glucans depends on the source they are isolated from. Native β-glucan molecules can be linked and branched in several ways. Biological properties of different β-glucan molecules are dependent on their molecular structure. Some authors claim that the β-(1→3), (1→6)-glucan derived from yeast Saccharomyces cerevisiae produce the highest biological effects. Thus, in this review the β-glucans and their metabolic activity are discussed, with the special accent on those isolated from yeast. Other possible β-glucan applications, directed to cosmetic production, non-medical application in pharmaceutical and chemical industry, are also discussed

Production of single-cell proteins by yeast Kluyveromyces fragilis on whey

Studirana je mogućnost kultivacije kvasca Kluyveromyces fragilis za proizvodnju mikrobnih proteina na sirutci u šaržnom i kontinuiranom postupku pri pH 5,0-5,5 i temperaturi od 40 °C. Ustanovljeno je eksperimentima na tresilici i laboratorijskom fermentoru da se kvasac dobro razmnožava pri odabranim uvjetima okoline, na 2 %-tnoj deproteiniziranoj sirutci s dodatkom diamonijevog sulfata i kalijevog hidrogen fosfata. Pri optimalnim uvjetima okoline postiže se stupanj konverzije laktoze u kvaščevu biomasu od 0,45-0,55 g s. tv. kvasca/g laktoze, specifična brzina rasta do 0,25 sat^-1 i produktivnost procesa do 1,3 g/L/sat. Kada se osnovnom supstratu doda 0,1 % kvaščevog ekstrakta kvasac se razmnožava brže, specifična brzina rasta poraste na 0,35-0,38 sat^-1, a produktivnost procesa dostiže 1,8 g/L/sat. Ukoliko se voda, potrebna za razrjeđenje sirutke, zamijeni melasnom džibrom, postiže se također povećanje brzine rasta kvasca K. fragilis. Specifična brzina rasta bila je do 0,40 sat^-1, a produktivnost procesa od 2,0-2,4 g/L/satThe possibility of cultivation of the yeast Kluyveromyces fragilis for the production of single-cell protein on deproteinated whey was studied. The hatch and the continuous cultivations were performed at pH 5.0-5.5 and the temperature of 40 °C. By experiments on the shaker and in laboratory fermenter it was established that the yeast cells grow well on 2 % deproteinated whey with the addition of ammonium sulphate and potassium hydrogen phosphate. At optimal conditions the biomass yield was 0.45-0.55 g DM/g lactose with the specific growth rate up to 0.25 h^-1 and productivity of 1.3 g/L/h. When 0.1 % of the yeast extract was added to the basic medium the yeast cells were multiplying faster (μ = 0.35-0.38 h^-1) and productivity was up to 1.8 g/L/h. If the water necessary for the dilution of whey was exchanged with molasses slop a. very good effect attained in the cultivation of yeast cells. The specific growth rate was 0.4 h^-1 and productivity up to 2.4 g/L/h