Biogenic amine content of boza: A traditional cereal-based, fermented Turkish beverage

WOS: 000258369600029Boza is a fermented beverage made from millet, maize, wheat or rice. Biogenic amine contents of 10 boza samples from different manufacturers in Turkey were analysed for the first time, using HPLC after derivatisation with benzoyl chloride. Of the I I biogenic amines under study, putrescine, spermidine and tyramine were detected in all boza samples. Tyramine was the prevailing biogenic at-nine. Tyramine concentrations of boza samples were between 13 and 65 mg/kg. Total biogenic amine contents of boza samples were between 25 and 69 mg/kg. Consequently, consumption of boza might represent a health risk for patients being treated with drugs containing monoamine oxidase inhibitor (MAOI). The pH values of boza samples were in the range from 3.16 to 4.02; total dry matters were from 15.3% to 31.1% (w/w): protein contents were from 0.50% to 0.99% (w/w). No significant correlations were detected between biogenic amine concentrations and pH, protein content and total dry matter content. (C) 2008 Elsevier Ltd. All rights reserved

Progress in the field of aspartic proteinases in cheese manufacturing: structures, functions, catalytic mechanism, inhibition, and engineering

WOS: 000324830700001Aspartic proteinases are an important class of proteinases which are widely used as milk-coagulating agents in industrial cheese production. They are available from a wide range of sources including mammals, plants, and microorganisms. Various attempts have been made in order to get insights into enzyme structure/function relationships for designing improved biocatalysts. This review provides an overview of historical background and recent achievements on the classification and structural characteristics of such enzymes as related to their functional properties, mechanism of catalysis, pH, and temperature dependence, substrate specificities, mechanism of inhibition, enzyme engineering, and technological applications with the focus on cheese manufacturing

A Thermolabile Aspartic Proteinase from Mucor mucedo DSM 809: Gene Identification, Cloning, and Functional Expression in Pichia pastoris

WOS: 000318308400057PubMed ID: 23065363In this study, the cDNA encoding the aspartic proteinase of Mucor mucedo DSM 809 has been identified by RNA ligased-mediated and oligo-capping rapid amplification of cDNA ends (RACE) technique. The gene contained an open reading frame of 1,200 bp and encoded for a signal peptide of 21 amino acid residues. Two N-glycosylation sites were observed within the identified sequence. The proteinase gene was cloned into the vector pGAPZ alpha A and expressed in Pichia pastoris X-33 for the first time. The protein has been secreted in functionally active form into the culture medium. The expression system does not require any acid activation process. The factors affecting the expression level were optimized in shaking flask cultures. Maximum enzyme production was observed with an initial medium pH of 3.5 at 20 A degrees C and 220 rpm shaking speed utilizing 4 % glucose as a carbon and energy source. The enzyme was purified with cation exchange chromatography and further studies revealed that the enzyme was secreted in glycosylated form. The purified enzyme exhibited remarkable sensitivity to thermal treatment and became completely inactivated after incubation at 55 A degrees C for 10 min. These results indicated that the recombinant proteinase could be considered as a potential rennet candidate for the cheese-making industry.Electroextraction Project, FP7-SME-2007-222220 [JUB 5103-50276]; PGSYS Project BMBF-ERA-Net, Euro TransBio-3 [BIO-010103441508 (JUB 5130-50290)]This work was partially supported by the Electroextraction Project, FP7-SME-2007-222220 (JUB 5103-50276) and the PGSYS Project BMBF-ERA-Net, Euro TransBio-3, BIO-010103441508 (JUB 5130-50290). The authors are indebted to Prof. Dr. Canan Tari for proof reading the article

A novel extremophilic xylanase produced on wheat bran from Aureobasidium pullulans NRRL Y-2311-1: Effects on dough rheology and bread quality

WOS: 000429962700041An extremophilic xylanase from Aureobasidium pullulans NRRL Y-2311-1 was produced on wheat bran and its performance in bread making was investigated for the first time. Two different world-wide-used commercial xylanase preparations were also applied in bread making as comparison. Effects of different enzyme dosages on various farinograph and extensograph properties of the dough and bread quality were evaluated in detail. The novel xylanase provided increase in water absorption, development time and stability of the dough and decrease in dough softening degree and mixing tolerance index at a dosage of 100 U/100 g flour. None of the enzymes provided reasonable increase in dough extensibility. There was no direct correlation between the extensograph properties (mainly, resistance and extension) of the bread dough and the bread specific volume. A. pullulans xylanase (125 U/100 g flour) provided remarkable improvement (30%) in bread specific volume as compared to the commercial counterparts. The moisture content values of all the bread samples were within the ideal limits (35-40%). A. pullulans xylanase was the most effective enzyme in decreasing the crumb firmness. Slight improvements in cohesiveness and remarkable decline in springiness and gumminess were observed for all the enzymes tested. The results of this study provide an opportunity for A. pullulans xylanase to be used in bread making at industrial scale. (C) 2018 Elsevier Ltd. All rights reserved.Scientific and Technological Research Council of Turkey-TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [TOVAG 112O521]This work was financially supported by The Scientific and Technological Research Council of Turkey-TUBITAK (Project No: TOVAG 112O521). This work is also included in Cost Action FP1306 entitled as "Valorisation of Lignocellulosic Biomass Side Streams for Sustainable Production of Chemicals, Materials & Fuels Using Low Environmental Impact Technologies"

Bioprocess strategies for production of xylanase on agro-residual products with Aureobasidium pullulans

WOS: 00034729860014

Processing of hazelnut (Corylus avellana L.) shell autohydrolysis liquor for production of low molecular weight xylooligosaccharides by Aureobasidium pullulans NRRL Y-2311-1 xylanase

Buyukkileci, Ali Oguz/0000-0002-0784-0008WOS:000619116700004In this study, a versatile process for the production of xylooligosaccharides (XOS) with a low degree of polymerization (DP 2-6) from hazelnut shells was designed. This process included autohydrolysis integrated with sequential enzymatic hydrolysis by crude xylanase produced with Aureobasidium pullulans NRRL Y-2311-1 from wheat bran. Autohydrolysis of hazelnut shells was carried out at a solid:liquid ratio of 1:6 (w/w) and 190 degrees C nonisothermally. The effects of several parameters on enzymatic hydrolysis of the autohydrolysis liquor were determined. The maximum XOS (DP 2-6) production was 22.5 g/L which was obtained at pH 5.0 and 40 degrees C using enzyme concentration of 240 U/g XOS and substrate concentration of 72 g/L. Under these conditions, 31.29 % of the substrate (total XOS) was converted to low-DP-XOS; xylobiose and xylotriose are being the major oligomers. This is the first study on the application of A. pullulans xylanase in production of xylooligomers from hazelnut shells.Scientific and Technological Research Council of Turkey-TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [TOVAG 213O126, TOVAG 112O521]This work was financially supported by The Scientific and Technological Research Council of Turkey-TUBITAK (Project Numbers: TOVAG 213O126 and TOVAG 112O521)

Production of extracellular aspartic protease in submerged fermentation with Mucor mucedo DSM 809

WOS: 000282232900021Fungal milk-clotting enzymes have gained value as bovine Chymosin substitutes in the cheese industry. In this work, the effects of culture conditions on the production of extracellular milk clotting enzymes from Mucor mucedo DSM 809 in submerged fermentation were studied. The maximum activity was observed after 48 h of cultivation at 24 degrees C in Erlenmeyer flasks. The optimized initial pH and shaking speed for enzyme production were 4.5 and 220 rpm, respectively. Glucose at a concentration of 1% (w/ v) was the best carbon source for the production of enzyme among the carbohydrates examined (glucose, fructose, lactose, maltodextrin). On the other hand casein at a concentration of 0.5% (w/v) was the selected nitrogen source in the media formulation. Under optimized conditions enzyme levels reached 130 SU per ml fermentation broth. The inoculum type and size has also affected biomass production and the biosynthesis of the enzyme. The preferred method was the inoculation of the culture media with spores at a total load of 6x10(5) spores per flask.BMBF-ERA-NetFederal Ministry of Education & Research (BMBF); Euro TransBio-3; [BIO-010103441508]; [JUB 5130-50290]This work was supported by BMBF-ERA-Net, euro TransBio-3, BIO-010103441508 (JUB 5130-50290)