scholarly journals Fermentative Microbes of Khadi, a Traditional Alcoholic Beverage of Botswana

Fermentation ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. 51
Author(s):  
Koketso Motlhanka ◽  
Kebaneilwe Lebani ◽  
Teun Boekhout ◽  
Nerve Zhou

Khadi is a popular traditional alcoholic beverage in rural households in Botswana. The product is produced by fermentation of ripened sun-dried Grewia flava (Malvaceae) fruits supplemented with brown table sugar. Despite its popularity, its growing consumer acceptance, its potential nutritional value, and its contribution to the socio-economic lifestyle of Botswana, the production process remains non-standardized. Non-standardized production processes lead to discrepancies in product quality and safety as well as varying shelf life. Identification of unknown fermentative microorganisms of khadi is an important step towards standardization of its brewing process for entrance into commercial markets. The aim of this study was to isolate and identify bacteria and yeasts responsible for fermentation of khadi. Yeasts and bacteria harbored in 18 khadi samples from 18 brewers in central and northern Botswana were investigated using classic culture-dependent techniques and DNA sequencing methods. Additionally, we used the same techniques to investigate the presence of bacteria and yeasts on six batches of ripened-dried G. flava fruits used for production of the sampled brews. Our results revealed that Saccharomyces cerevisiae closely related to a commercial baker’s yeast strain sold locally was the most predominant yeast species in khadi suggesting a possible non-spontaneous brewing process. However, we also detected diverse non-Saccharomyces yeasts, which are not available commercially in retail shops in Botswana. This suggests that spontaneous fermentation is partially responsible for fermentation of khadi. This study, presenting the first microbiological characterization of a prominent traditional alcoholic beverage in Botswana, is vital for development of starter cultures for the production of a consistent product towards the commercialization of khadi.

2012 ◽  
Vol 63 (3) ◽  
pp. 863-869 ◽  
Author(s):  
Alak K. Buragohain ◽  
Bhaben Tanti ◽  
Hridip K. Sarma ◽  
Pranjan Barman ◽  
Kishore Das

2021 ◽  
Author(s):  
Angela Capece ◽  
Angela Pietrafesa ◽  
Gabriella Siesto ◽  
Rocchina Pietrafesa ◽  
Victor Garrigos ◽  
...  

The bulk of grape juice fermentation is carried out by the yeast Saccharomyces cerevisiae, but non-Saccharomyces yeasts can modulate many sensorial aspects of the final products in ways not well understood. In this study, some of such non-conventional yeasts were screened as mixed starter cultures in a fermentation defined medium in both simultaneous and sequential inoculations. One strain of Starmerella bacillaris and another of Zygosaccharomyces bailii were chosen by their distinct phenotypic footprint and their ability to reduce ethanol levels at the end of fermentation, particularly during simultaneous vinification. S. bacillaris losses viability strongly at the end of mixed fermentation, while Z. bailii remains viable until the end of vinification. Interestingly, for most non-Saccharomyces yeasts, simultaneous inoculation helps for survival at the end of fermentation compared to sequential inoculation. S. cerevisiae viability was unchanged by the presence of the either yeast. Characterization of both strains indicates that S. bacillaris behavior is overall more different from S. cerevisiae than Z. bailii. S. bacillaris has a less strict glucose repression mechanism and molecular markers like catabolite repression kinase Snf1 is quite different in size. Besides, S. cerevisiae transcriptome changes to a bigger degree in the presence of S. bacillaris than when inoculated with Z. bailii. S. bacillaris induces the translation machinery and repress vesicular transport. Both non-Saccharomyces yeast induce S. cerevisiae glycolytic genes, and that may be related to ethanol lowering, but there are specific aspects of carbon-related mechanisms between strains: Z. bailii presence increases the stress-related polysaccharides trehalose and glycogen while S. bacillaris induces gluconeogenesis genes.


2019 ◽  
Vol 7 (12) ◽  
pp. 606 ◽  
Author(s):  
Zhewei Song ◽  
Hai Du ◽  
Menghui Zhang ◽  
Yao Nie ◽  
Yan Xu

The spontaneous fermentation of alcoholic beverage is a bioprocess donated by microbiota with complex stress environments. Among various microbes, non-Saccharomyces yeasts have high stress tolerance and significantly affect the taste and quality of products in process. Although many researchers have focused on the influence of acid stress, the mechanism of non-Saccharomyces yeasts to tolerant stress remains unclear in microbiota. To bridge the gap, we constructed in situ and in vitro studies to explore the reduction pathway of acetic acid in non-Saccharomyces yeasts. In this study, we found Schizosaccharomyces pombe has special capacities to resist 10 g/L acetic acid in laboratory cultures and decrease the average concentration of acetic acid from 9.62 to 6.55 g/kg fermented grains in Chinese Maotai-flavor liquor (Baijiu) production. Moreover, Schi. pombe promoted metabolic level of mevalonate pathway (high expressions of gene ACCAT1, HMGCS1, and HMGCR1) to degrade a high concentration of acetic acid. Meanwhile, Schi. pombe also improved the concentration of mevalonic acid that is the precursor of terpenes to enhance the taste and quality of Baijiu. Overall, the synchronicity of reduction and generation in Schi. pombe advances the current knowledge to guide more suitable strategies for mechanism studies of non-Saccharomyces yeasts in fermented industries of alcoholic beverages.


Fruits ◽  
2016 ◽  
Vol 71 (4) ◽  
pp. 215-220 ◽  
Author(s):  
Elisa Alonso González ◽  
Ignacio Orriols Fernández ◽  
Lorenzo Pastrana Castro ◽  
Nelson Pérez Guerra
Keyword(s):  

Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1336
Author(s):  
Fatjona Fejzullahu ◽  
Zsuzsanna Kiss ◽  
Gabriella Kun-Farkas ◽  
Szilárd Kun

The use of non-Saccharomyces yeasts for alcoholic beverage improvement and diversification has gained considerable attention in recent years. The effect of pure and mixed inocula (of Torulaspora delbrueckii, Lachancea thermotolerans, and Saccharomyces cerevisiae) on apple mash fermentation has been determined for the production of Hungarian fruit spirit (Pálinka), with a special emphasis on the chemical, volatile, and sensory attributes. The enological parameters were followed during the fermentation process. Sugar consumption and organic acid production were determined by HPLC, whereas the aromatic profile of the distillates was characterized by GC-FID. According to the results, single and mixed cultures showed similar characteristics during mash fermentation. The identified volatile compounds included aldehydes, esters, and higher alcohols. Mixed culture fermentation trials revealed a significantly higher concentration of volatile compounds and better sensorial attributes compared to those exhibited by the pure culture of S. cerevisiae.


2021 ◽  
Vol 21 (3) ◽  
Author(s):  
João Drumonde-Neves ◽  
Ticiana Fernandes ◽  
Teresa Lima ◽  
Célia Pais ◽  
Ricardo Franco-Duarte

ABSTRACT Non-Saccharomyces yeast species are nowadays recognized for their impact on wine´s chemical composition and sensorial properties. In addition, new interest has been given to the commercial exploitation of non-Saccharomyces starter cultures in the wine sector. However, over many years, these yeast species were considered sources of contamination in wine production and conservation, mainly due to the high levels of volatile acidity obtained. The present manuscript systematizes 80 years of literature describing non-Saccharomyces yeast species isolated from grapes and/or grape musts. A link between each reference, the accepted taxonomic name of each species and their geographical occurrence is presented, compiling information for 293 species, in a total of 231 citations. One major focus of this work relates to the isolation of non-Saccharomyces yeasts from grapevines usually ignored in most sampling studies, also as isolation from damaged grapes. These particular niches are sources of specific yeast species, which are not identified in most other explored environments. These yeasts have high potential to be explored for important and diversified biotechnological applications.


Beverages ◽  
2020 ◽  
Vol 6 (1) ◽  
pp. 3 ◽  
Author(s):  
Fabrizio Iattici ◽  
Martina Catallo ◽  
Lisa Solieri

Beer is a fermented beverage with a history as old as human civilization. Ales and lagers are by far the most common beers; however, diversification is becoming increasingly important in the brewing market and the brewers are continuously interested in improving and extending the range of products, especially in the craft brewery sector. Fermentation is one of the widest spaces for innovation in the brewing process. Besides Saccharomyces cerevisiae ale and Saccharomyces pastorianus lager strains conventionally used in macro-breweries, there is an increasing demand for novel yeast starter cultures tailored for producing beer styles with diversified aroma profiles. Recently, four genetic engineering-free approaches expanded the genetic background and the phenotypic biodiversity of brewing yeasts and allowed novel costumed-designed starter cultures to be developed: (1) the research for new performant S. cerevisiae yeasts from fermented foods alternative to beer; (2) the creation of synthetic hybrids between S. cerevisiae and Saccharomyces non-cerevisiae in order to mimic lager yeasts; (3) the exploitation of evolutionary engineering approaches; (4) the usage of non-Saccharomyces yeasts. Here, we summarized the pro and contra of these approaches and provided an overview on the most recent advances on how brewing yeast genome evolved and domestication took place. The resulting correlation maps between genotypes and relevant brewing phenotypes can assist and further improve the search for novel craft beer starter yeasts, enhancing the portfolio of diversified products offered to the final customer.


2015 ◽  
Vol 203 ◽  
pp. 35-40 ◽  
Author(s):  
L.D. Reina ◽  
I.M. Pérez-Díaz ◽  
F. Breidt ◽  
M.A. Azcarate-Peril ◽  
E. Medina ◽  
...  

2021 ◽  
pp. 103867
Author(s):  
Shiqi Li ◽  
Pengfei Bi ◽  
Nan Sun ◽  
Zhiyi Gao ◽  
Xiaowen Chen ◽  
...  
Keyword(s):  

Author(s):  
S. M. Umar ◽  
F. U. Maigari ◽  
J. J. Idi ◽  
J. Salome

The study was conducted to determine the levels of magnesium, phosphorus, potassium and calcium present in Zobo Drink consumed in Gombe metropolis. Zobo (Hibiscus sabdariffa) drink has been consumed for decades as a non-alcoholic beverage, thus, the knowledge of its nutritional value is of huge interest. Hence, it is important to determine the level of some minerals present in the beverage. Ten samples were bought from different retailers within Gombe metropolis and were digested using Aqua regia (1:3 of HNO3 and HCL) in the laboratory and the levels of the various elements in each sample were determined using Atomic Absorption Spectroscopy (AAS). The results obtained showed that the sample from Gombe State University commercial area 1 has the highest (P<0.05) magnesium content (9.38.±0.02 mg/kg). Calcium (2.90.±0.02 mg/kg) and Phosphorus (9.11.±0.02 mg/kg) were found to be highest in samples obtained from Arawa market and Gombe State University commercial area 2 respectively. Potassium was (14.45.±0.05 mg/kg) was highest in the beverage gotten from Gombe State University commercial area 2. The results showed that Zobo drink sold in Gombe metropolis possess some amount of the assayed  minerals but are lower than the Regular Dietary Intake (RDI) permissible by the World Health Organisation.


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