title: Automated quantification of budding Saccharomyces cerevisiae using a novel image cytometry method.
abstract: The measurements of concentration, viability, and budding percentages of Saccharomyces cerevisiae are performed on a routine basis in the brewing and biofuel industries. Generation of these parameters is of great importance in a manufacturing setting, where they can aid in the estimation of product quality, quantity, and fermentation time of the manufacturing process. Specifically, budding percentages can be used to estimate the reproduction rate of yeast populations, which directly correlates with metabolism of polysaccharides and bioethanol production, and can be monitored to maximize production of bioethanol during fermentation. The traditional method involves manual counting using a hemacytometer, but this is time-consuming and prone to human error. In this study, we developed a novel automated method for the quantification of yeast budding percentages using Cellometer image cytometry. The automated method utilizes a dual-fluorescent nucleic acid dye to specifically stain live cells for imaging analysis of unique morphological characteristics of budding yeast. In addition, cell cycle analysis is performed as an alternative method for budding analysis. We were able to show comparable yeast budding percentages between manual and automated counting, as well as cell cycle analysis. The automated image cytometry method is used to analyze and characterize corn mash samples directly from fermenters during standard fermentation. Since concentration, viability, and budding percentages can be obtained simultaneously, the automated method can be integrated into the fermentation quality assurance protocol, which may improve the quality and efficiency of beer and bioethanol production processes.
authors.affiliation: Department of Technology R&D, Nexcelom Bioscience LLC, 360 Merrimack St. Building 9, Lawrence, MA 01843, USA.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Laverty
authors.forename: Alexandria L
authors.initials: AL
authors.lastname: Kury
authors.forename: Dmitry
authors.initials: D
authors.lastname: Kuksin
authors.forename: Alnoor
authors.initials: A
authors.lastname: Pirani
authors.forename: Kevin
authors.initials: K
authors.lastname: Flanagan
authors.forename: Leo Li-Ying
authors.initials: LL
authors.lastname: Chan
mesh_terms: D001331:Automation; D001515:Beer / Q000382:microbiology; D056804:Biofuels; D002453:Cell Cycle; D005285:Fermentation; D019044:Image Cytometry / Q000379:methods*; D050296:Microbial Viability; D019370:Observation; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000254:growth & development / Q000302:isolation & purification*; D003313:Zea mays / Q000382:microbiology
chemical_list: D056804:Biofuels
references.citation: Methods Enzymol. 1997;283:322-32
references.pmid: 9251030
references.citation: J Cell Biol. 1977 Nov;75(2 Pt 1):422-35
references.pmid: 400873
references.citation: Microbiol Rev. 1988 Dec;52(4):536-53
references.pmid: 3070323
references.citation: J Ind Microbiol Biotechnol. 2011 Aug;38(8):1109-15
references.pmid: 20960026
references.citation: Genetics. 2007 Mar;175(3):1479-87
references.pmid: 17194785
references.citation: J Microbiol Methods. 2004 Nov;59(2):289-92
references.pmid: 15369865
references.citation: Lab Hematol. 2004;10(2):109-11
references.pmid: 15224767
references.citation: J Ind Microbiol Biotechnol. 2012 Nov;39(11):1615-23
references.pmid: 22864608
references.citation: Biophys J. 1998 May;74(5):2702-13
references.pmid: 9591694
references.citation: J Biol Chem. 1971 Jan 10;246(1):152-9
references.pmid: 5541754
references.citation: J Biomed Opt. 2001 Jul;6(3):287-91
references.pmid: 11516318
references.citation: J Fluoresc. 2010 Jan;20(1):343-52
references.pmid: 19882237
references.citation: Biotechnol Prog. 1991 Jul-Aug;7(4):291-8
references.pmid: 1367343
references.citation: Cytometry A. 2008 Sep;73(9):825-33
references.pmid: 18613038