ABSTRACT
The aim ofthis study was to
assess the growth and physiological properties oftop and bottom fermenting
yeasts from palm wine. 10 randomly selected palm wine samples were collected
from different locations within Ikwuano local government area of Abia state.
The samples were cultured by streaking and spread plate method, Yeasts were
isolated from palm wine and subsequently characterized and identified. Results
showed that (two top and two bottom fermenters) were isolated with varying
prevalence in palm wine samples. The four isolates were Saccharomyces
cerevisiae, Saccharomyces globosus (top fermenters), Saccharomyces
carlsbengensis and Saccharomyces uvarum (bottom fermenters). S. cerevisiae was
found in all samples while S. globosus and S. carlsbengensis had 80% and 60%
respectively with S. uvarum having the least occurrence (40%). The different
yeasts have similarities in their growth physiological activities. The isolates
show potentials to manage growth stress conditions. S. cerevisiae, had the best
temperature tolerance (+ at 42°C) while S. uvarum recorded the least growth (+)
at 39°C. Some ofthe isolates demonstrated flocculation ability and were
positive in fermentative and assimilation test for glucose and other sugars.
Three of the yeast isolates did not grow well at pH 2.0 but rather had just
slight growth level (+). S. uvarum did not grow at pH 2.0. At pH 4.0, S.
cerevisiae and S. globosus grew profusely (+++), S. carlsbengensis and 5.
uvarum had moderate growth (++). All the yeasts grew very well at pH 6.0. At
ethanol concentration less than 10% (< 10% v/v), three of the isolates
except S. uvarum recorded slight growth at 16% ethanol concentration. None was
able to grow at 19% ethanol concentration. CuSo4 tolerance test recorded
moderate growth (++) for each yeast at 1.0g/l copper, slight growth (+) at
2.0g/l and no growth at 3.0g/l. All the yeasts were able to grow at 0.01% -
0.02% of sodium metabisulfite, the isolates recorded low response at 0.03%
concentration. Only S', cerevisiae and S. globosus had slight growth at 0.04%
but S’, carlsbengensis and S', uvarum show no growth at 0.04% and none ofthe
isolates was able to grow at 0.05% Comparatively, sucrose was the most suitable
sugar from all the yeasts while S', cerevisiae had the highest CO2 production
capacity among with 0.27ml/min. S. uvarum had the least CO2 production rate
with 0.16ml/min. The result showed the ability of the yeasts to adapt to
various parameters and the level of tolerance was dependent on intensity or
concentration ofthe various parameters.
OBASI, O (2023). Growth And Physiological Studies Of Top And Bottom Fermenting Yeasts From Palm Wine:- Obasi, Tochi O.. Repository.mouau.edu.ng: Retrieved Sep 08, 2024, from https://repository.mouau.edu.ng/work/view/growth-and-physiological-studies-of-top-and-bottom-fermenting-yeasts-from-palm-wine-obasi-tochi-o-7-2
OBASI, OBASI. "Growth And Physiological Studies Of Top And Bottom Fermenting Yeasts From Palm Wine:- Obasi, Tochi O." Repository.mouau.edu.ng. Repository.mouau.edu.ng, 23 Oct. 2023, https://repository.mouau.edu.ng/work/view/growth-and-physiological-studies-of-top-and-bottom-fermenting-yeasts-from-palm-wine-obasi-tochi-o-7-2. Accessed 08 Sep. 2024.
OBASI, OBASI. "Growth And Physiological Studies Of Top And Bottom Fermenting Yeasts From Palm Wine:- Obasi, Tochi O.". Repository.mouau.edu.ng, Repository.mouau.edu.ng, 23 Oct. 2023. Web. 08 Sep. 2024. < https://repository.mouau.edu.ng/work/view/growth-and-physiological-studies-of-top-and-bottom-fermenting-yeasts-from-palm-wine-obasi-tochi-o-7-2 >.
OBASI, OBASI. "Growth And Physiological Studies Of Top And Bottom Fermenting Yeasts From Palm Wine:- Obasi, Tochi O." Repository.mouau.edu.ng (2023). Accessed 08 Sep. 2024. https://repository.mouau.edu.ng/work/view/growth-and-physiological-studies-of-top-and-bottom-fermenting-yeasts-from-palm-wine-obasi-tochi-o-7-2