Characterization of Yeasts Isolated from Parmigiano Reggiano Cheese Natural Whey Starter: From Spoilage Agents to Potential Cell Factories for Whey Valorization

Whey is the main byproduct of the dairy industry and contains sugars (lactose) and proteins (especially serum proteins and, at lesser extent, residual caseins), which can be valorized by the fermentative action of yeasts. In the present study, we characterized the spoilage yeast population inhabiting natural whey starter (NWS), the undefined starter culture of thermophilic lactic acid bacteria used in Parmigiano Reggiano (PR) cheesemaking, and evaluated thermotolerance, mating type, and the aptitude to produce ethanol and bioactive peptides from whey lactose and proteins, respectively, in a selected pool of strains. PCR-RFLP assay of ribosomal ITS regions and phylogenetic analysis of 26S rDNA D1/D2 domains showed that PR NWS yeast population consists of the well-documented Kluyveromyces marxianus, as well as of other species (Saccharomyces cerevisiae, Wickerhamiella pararugosa, and Torulaspora delbrueckii), with multiple biotypes scored within each species as demonstrated by (GTG)5-based MSP-PCR. Haploid and diploid K. marxianus strains were identified through MAT genotyping, while thermotolerance assay allowed the selection of strains suitable to grow up to 48 °C. In whey fermentation trials, one thermotolerant strain was suitable to release ethanol with a fermentation efficiency of 86.5%, while another candidate was able to produce the highest amounts of both ethanol and bioactive peptides with potentially anti-hypertensive function. The present work demonstrated that PR NWS is a reservoir of ethanol and bioactive peptides producer yeasts, which can be exploited to valorize whey, in agreement with the principles of circularity and sustainability.

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Characterization of Yeasts Isolated From Parmigiano Reggiano Cheese Natural Whey Starter: From Spoilage Agents to Potential Cell Factories for Whey Valorization

10.20944/preprints202109.0210.v1 ◽

2021 ◽

Author(s):

Serena Martini ◽

Mattia Bonazzi ◽

Ilaria Malorgio ◽

Valentina Pizzamiglio ◽

Davide Tagliazucchi ◽

...

Keyword(s):

Bioactive Peptides ◽

Serum Proteins ◽

Starter Culture ◽

Cell Factories ◽

Spoilage Yeast ◽

Thermotolerant Strain ◽

Thermophilic Lactic Acid Bacteria ◽

Parmigiano Reggiano ◽

Selection Of

Whey is the main by-product of the dairy industry and contains sugars (lactose) and proteins (especially serum proteins and, at lesser extent, residual caseins), which can be valorized by the fermentative action of yeasts. In the present study, we characterized the spoilage yeast fraction inhabiting natural whey starter (NWS), the undefined starter culture of thermophilic lactic acid bacteria used in Parmigiano Reggiano (PR) cheesemaking, and evaluated thermotolerance, mating type, and the aptitude to produce ethanol and bioactive peptides from whey lactose and proteins, respectively, in a selected pool of strains. We found that PR NWS yeast population consists of other species (Saccharomyces cerevisiae, Wickerhamiella pararugosa, and Torulaspora delbrueckii) in addition to the well-documented Kluyveromyces marxianus, with multiple biotypes scored within each species. Haploid and diploid K. marxianus strains were identified through MAT genotyping, while thermotolerance assay allowed the selection of strains suitable to grow up to 48 °C. In whey fermentation assay, one thermotolerant strain was suitable to release ethanol with yield of 86.5%, while another candidate was able to produce the highest amounts of both ethanol and bioactive peptides with potentially anti-hypertensive function. The present work demonstrated that PR NWS is a reservoir of ethanol and bioactive peptides producer yeasts, which can be exploited to valorize whey, in agreement with the principles of circularity and sustainability.

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Characterization of Cell-Envelope Proteinases from Two Lacticaseibacillus casei Strains Isolated from Parmigiano Reggiano Cheese

Biology ◽

10.3390/biology11010139 ◽

2022 ◽

Vol 11 (1) ◽

pp. 139

Author(s):

Lisa Solieri ◽

Laura Sola ◽

Amanda Vaccalluzzo ◽

Cinzia Randazzo ◽

Serena Martini ◽

...

Keyword(s):

Food Production ◽

Bioactive Peptides ◽

Cell Envelope ◽

Residual Activity ◽

Fermented Food ◽

Serine Proteinases ◽

Peptide Bonds ◽

Caseinolytic Activity ◽

Parmigiano Reggiano

In the present work, two cell-envelope proteinases (CEPs) from Lacticaseibacillus casei strains PRA205 and 2006 were characterized at both the biochemical and genetic levels. The genomes of both L. casei strains included two putative CEPs genes prtP2 and prtR1, but only prtR1 was transcribed. The extracted PrtR1 proteinases were serine proteinases with optimal activity at 40 °C and pH 7.5, and were activated by Ca2+ ions. Interestingly, PrtR1 from L. casei PRA205 exhibited high residual activity at pH 4 and at 5 °C, suggesting its possible exploitation for fermented food production. The caseinolytic activity against αS1- and β-casein indicated that both PrtR1s belonged to the PI/PIII type. These PrtR1s cleaved β-casein peptide bonds preferentially when amino acid M or N was present at the P1 subsite and amino acids A and D were at the P1′ subsite. Several bioactive peptides were found to be released from PrtR1 after αs1- and β-casein hydrolysis.

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Collection and characterization of banana gene pools (Musa spp.) in Manipur (N.E. India) using PCR–RFLP and RAPD and ISSR markers

Revista Brasileira de Botânica ◽

10.1007/s40415-021-00722-y ◽

2021 ◽

Author(s):

Warepam Amuchou Singh ◽

Nandeibam Samarjit Singh ◽

Elangbam Julia Devi ◽

Pratap Jyoti Handique ◽

Huidrom Sunitibala Devi

Keyword(s):

Issr Markers ◽

Gene Pools ◽

Musa Spp ◽

Pcr Rflp ◽

Rapd And Issr

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Molecular characterization of HEK293 cells as emerging versatile cell factories

Current Opinion in Biotechnology ◽

10.1016/j.copbio.2021.05.001 ◽

2021 ◽

Vol 71 ◽

pp. 18-24

Author(s):

Michela Pulix ◽

Vera Lukashchuk ◽

Daniel C Smith ◽

Alan J Dickson

Keyword(s):

Molecular Characterization ◽

Hek293 Cells ◽

Cell Factories

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Production and Characterization of a Novel Gluten-Free Fermented Beverage Based on Sprouted Oat Flour

Foods ◽

10.3390/foods10010139 ◽

2021 ◽

Vol 10 (1) ◽

pp. 139

Author(s):

Natalia Aparicio-García ◽

Cristina Martínez-Villaluenga ◽

Juana Frias ◽

Elena Peñas

Keyword(s):

Starter Culture ◽

Microbial Quality ◽

Pathogenic Microorganisms ◽

Gluten Free ◽

Good Source ◽

Fermented Beverage ◽

Oat Flour ◽

Hedonic Scale ◽

Acetic Acids

This study investigates the use of sprouted oat flour as a substrate to develop a novel gluten-free beverage by fermentation with a probiotic (Lactobacillus plantarum WCFS1) starter culture. Physicochemical, microbiological, nutritional and sensory properties of sprouted oat fermented beverage (SOFB) were characterized. After fermentation for 4 h, SOFB exhibited an acidity of 0.42 g lactic acid/100 mL, contents of lactic and acetic acids of 1.6 and 0.09 g/L, respectively, and high viable counts of probiotic starter culture (8.9 Log CFU/mL). Furthermore, SOFB was a good source of protein (1.7 g/100 mL), β-glucan (79 mg/100 mL), thiamine (676 μg/100 mL), riboflavin (28.1 μg/100 mL) and phenolic compounds (61.4 mg GAE/100 mL), and had a high antioxidant potential (164.3 mg TE/100 mL). Spoilage and pathogenic microorganisms were not detected in SOFB. The sensory attributes evaluated received scores higher than 6 in a 9-point hedonic scale, indicating that SOFB was well accepted by panelists. Storage of SOFB at 4 °C for 20 days maintained L. plantarum viability and a good microbial quality and did not substantially affect β-glucan content. SOFB fulfils current consumer demands regarding natural and wholesome plant-based foods.

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