Genomics Technologies for Enhanced Understanding of Robustness of LAB Starter Cultures

Author(s):  
Annereinou R. Dijkstra ◽  
Peter A. Bron

During production and application, starter culture strains encounter several stresses. To ensure an adequate contribution to the fermentation process, starter culture strains should remain viable, justifying the increasing industrial efforts to unravel robustness characteristics of LAB starter culture strains. Nowadays, large numbers of genome sequences are publicly available, which enables the employment of several genomics technologies to increase our understanding of robustness. This aids the improvement of currently applied LAB starter culture strains and supports the industrial application of novel strains with specific desirable traits but currently inadequate robustness characteristics. This chapter explores genomics technologies for enhanced understanding of robustness of LAB starter cultures.

10.5219/1377 ◽  
2020 ◽  
Vol 14 ◽  
pp. 300-306
Author(s):  
Peter Zajác ◽  
Lenka Kúšová ◽  
Lucia Benešová ◽  
Jozef Čapla ◽  
Jozef Čurlej ◽  
...  

In this work, we have compared and described the fermentation process of two commercial yogurt starter cultures during the white yogurt production. We used freeze-dried thermophilic starter culture YoFlex® YF - L812 and deep-frozen starter culture Delvo® Fresh YS – 241 for the production of white yogurts. We analysed titration acidity, active acidity, total viable counts, texture, and sensory parameters of white yogurts produced in laboratory conditions. This research was performed for dairy company Mliekareň Kopanice Selce, s.r.o., Slovakia. We did not found statistically significant differences (p >0.05) in titration acidity of both yogurts after 7 hours of fermentation. We did not found statistically significant differences (p >0.05) in the pH of both yogurts after 7 hours of fermentation. We found statistically significant differences (p <0.05) in all textural parameters (hardness, consistency, cohesion, and viscosity). The total viable count of microorganisms in yogurts after 24 hours of fermentation was 6.28 x 107 and 7.14 x 107 respectively.


2019 ◽  
Vol 2019 ◽  
pp. 1-6 ◽  
Author(s):  
Mesfin Haile ◽  
Won Hee Kang

Coffee is one of the most important and widely used commercial crops in the world. After ripe coffee cherries are harvested, coffee must pass through several steps to become (green) raw coffee beans. Commonly, there are three different processing methods used to obtain green coffee beans from coffee cherries, namely, the wet, dry, and semidry methods. Microorganisms (yeasts and bacteria) play a major role in coffee fermentation process by degrading mucilage by producing different enzymes (pectinase), acids, and alcohols. Starter culture development is crucial and is done by selecting microorganisms that have certain characteristics, such as mucilage degradation ability, tolerance to stress during fermentation, the ability to suppress the growth of pathogenic fungi, and a positive impact on the sensory quality of the coffee. Currently, green coffee beans obtained from farms that use any of the above processing methods are fermented with selected microorganisms to improve the flavour and aroma of the coffee. This is the result of a new insight into the development of unique flavoured coffee and into engaging with the coffee market to better benefit. This review gives a comprehensive overview of the fermentation process, microorganisms and starter cultures, and fermentation’s impact on coffee quality. Future prospects are also discussed through the incorporation of recent research.


Fermentation ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 278
Author(s):  
Vanessa Bassi Pregolini ◽  
Gilberto Vinícius de Melo Pereira ◽  
Alexander da Silva Vale ◽  
Dão Pedro de Carvalho Neto ◽  
Carlos Ricardo Soccol

Microbial activity is an integral part of agricultural ecosystems and can influence the quality of food commodities. During on-farm processing, coffee growers use a traditional method of fermentation to remove the cherry pulp surrounding the beans. Here, we investigated the influence of the coffee farm microbiome and the resulting fermentation process conducted with selected starter cultures (Pichia fermentans YC5.2 and Pediococcus acidilactici LPBC161). The microbiota of the coffee farm (coffee fruits and leaves, over-ripe fruits, cherries before de-pulping, depulped beans, and water used for de-pulping beans) was dominated by Enterobacteriaceae and Saccharomycetales, as determined by llumina-based amplicon sequencing. In addition, 299 prokaryotes and 189 eukaryotes were identified. Following the fermentation process, Pichia and the family Lactobacillaceae (which includes P. acidilactici) represented more than 70% of the total microbial community. The positive interaction between the starters resulted in the formation of primary metabolites (such as ethanol and lactic acid) and important aroma-impacting compounds (ethyl acetate, isoamyl acetate, and ethyl isobutyrate). The success competitiveness of the starters towards the wild microbiota indicated that coffee farm microbiota has little influence on starter culture-added coffee fermentation. However, hygiene requirements in the fermentation process should be indicated to prevent the high microbial loads present in coffee farm soil, leaves, fruits collected on the ground, and over-ripe fruits from having access to the fermentation tank and transferring undesirable aromas to coffee beans.


Fermentation ◽  
2021 ◽  
Vol 7 (1) ◽  
pp. 43
Author(s):  
Ilaria Checchia ◽  
Renato L. Binati ◽  
Eleonora Troiano ◽  
Maurizio Ugliano ◽  
Giovanna E. Felis ◽  
...  

Wine quality is strongly affected by chemical composition and microbial population of grape must, which, in turn, are influenced by several post-harvest treatments, including grape withering. Different strategies have been suggested to manage the fermenting must microbiota, as it plays a central role in the outcomes of both spontaneous and guided fermentations. This study aimed at evaluating the impact of grape washing, SO2 addition, and selected starter culture inoculation on population dynamics, fermentation kinetics, and main oenological parameters in lab-scale trials, focusing on withered grapes usually used for Amarone production. Although grape washing treatment was effective in removing heavy metals and undesirable microorganisms from grape berry surface, inoculation of multi-starter cultures impacted more fermentation rates. Further, both grape washing and starter inoculation procedures had a remarkable impact on wine chemical characteristics, while 30 mg/L SO2 addition did not significantly affect the fermentation process. In summary, the best strategy in terms of limiting off-flavors and potentially reducing the need for SO2 addition in wine from withered grapes was the use of yeast starters, particularly mixed cultures composed by selected strains of Metschnikowia spp. and Saccharomyces cerevisiae. Application of a washing step before winemaking showed a potential to improve organoleptic characteristics of wine.


2020 ◽  
Vol 29 (12) ◽  
pp. 59-63
Author(s):  
O.I. Parakhina ◽  
◽  
M.N. Lokachuk ◽  
L.I. Kuznetsova ◽  
E.N. Pavlovskaya ◽  
...  

The research was carried out within the framework of the theme of state assignment № 0593–2019–0008 «To develop theoretical foundations for creating composite mixtures for bakery products using physical methods of exposure that ensure homogeneity, stability of mixtures and bioavailability of nutrients, to optimize diets population of Russia». The data on the species belonging of new strains of lactic acid bacteria and yeast isolated from samples of good quality gluten-free starter cultures are presented. A comparative assessment of the antagonistic and acid-forming activity of strains of lactic acid bacteria and the fermentative activity of yeast was carried out. The composition of microbial compositions from selected strains of LAB and yeast was developed. The influence of the starter culture on the new microbial composition on the physicochemical, organoleptic indicators of the bread quality and resistance to mold and ropy-disease was investigated.


1995 ◽  
Vol 58 (1) ◽  
pp. 62-69 ◽  
Author(s):  
K. ANJAN REDDY ◽  
ELMER H. MARTH

Three different split lots of Cheddar cheese curd were prepared with added sodium chloride (NaCl) potassium chloride (KCl) or mixtures of NaCl/KCl (2:1 1:1 1:2 and 3:4 all on wt/wt basis) to achieve a final salt concentration of 1.5 or 1.75%. At intervals during ripening at 3±1°C samples were plated with All-Purpose Tween (APT) and Lactobacillus Selection (LBS) agar. Isolates were obtained of bacteria that predominated on the agar media. In the first trial (Lactococcus lactis subsp. lactis plus L. lactis subsp. cremoris served as starter cultures) L. lactis subsp.lactis Lactobacillus casei and other lactobacilli were the predominant bacteria regardless of the salting treatment Received by the cheese. In the second trial (L. lactis subsp. lactis served as the starter culture) unclassified lactococci L. lactis subsp. lactis unclassified lactobacilli and L. casei predominated regardless of the salting treatment given the cheese. In the third trial (L. lactis subsp. cremoris served as the starter culture) unclassified lactococci unclassified lactobacilli L. casei and Pediococcus cerevisiae predominated regardless of the salting treatment applied to the cheese Thus use of KCl to replace some of the NaCl for salting cheese had no detectable effect on the kinds of lactic acid bacteria that developed in ripening Cheddar cheese.


1943 ◽  
Vol 13 (2) ◽  
pp. 123-126 ◽  
Author(s):  
G. J. E. Hunter ◽  
H. R. Whitehead

If milk containing the inhibitory substance produced by growth of ‘non-acid’ streptococci is used for the propagation of starter, it can cause delayed coagulation, simulating a starter failure caused by bacteriophage. ‘Non-acid’ milk in the starter culture milk affects cultures differently according to the particular strains of streptococci present; some strains are considerably less inhibited than others.


2018 ◽  
Vol 21 (0) ◽  
Author(s):  
Claudia Fieira ◽  
João Francisco Marchi ◽  
Daiana Marafão ◽  
Alexandre da Trindade Alfaro

Abstract Italian salami is a cured meat with high sodium contents which is easy, fast and convenient to consume. Starter cultures are used to improve its sensory characteristics and refine its technological manufacturing process. The goal of this study was to reduce the sodium content in Italian salami through the partial replacement of sodium chloride by potassium chloride, magnesium chloride and calcium chloride, and evaluate the viability of the Lactobacillus sp. and Staphylococcus sp. cells found in the starter culture. Four formulations were elaborated: one with, and one without the starter culture, but both with the addition of sodium chloride; and two with the partial replacement of 60% of the sodium chloride: the first with KCl, and the other with a mixture of KCl, MgCl2 and CaCl2. Physicochemical and microbiological evaluations were carried out to monitor the ripening and the quality of the final product. The partial replacement of NaCl by other salts (MgCl2, CaCl2, KCl) did not interfere in the growth of the starter culture in the Italian salami, neither did it affect the majority of the physicochemical parameters of the Italian salami nor the microbiological quality of the final product.


1979 ◽  
Vol 42 (7) ◽  
pp. 572-576 ◽  
Author(s):  
LAURA L. ZAIKA ◽  
JOHN C. KISSINGER

Ginger, red pepper, mustard, mace, cinnamon and clove were examined to determine their effects on growth of and acid production by a starter culture containing Lactobacillus plantarum and Pediococcus cerevisiae in a liquid medium. At 4, 8, and 12 g/l levels all spices except clove stimulated acid production by the starter bacteria but did not stimulate increases in bacterial population. Clove was inhibitory to the starter bacteria at and above the 4 g/l level, but low concentrations (0.5 – 2.0 g/l) stimulated acid production. High concentrations of cinnamon (8 and 12 g/l) delayed acid production, but bacterial counts were similar to those of the control.


2006 ◽  
Vol 12 (1) ◽  
pp. 11-17 ◽  
Author(s):  
Claude Champagne

Lactic cultures are widely used in food fermentations and as probiotic supplements. Some strains are damaged by the various steps of fermentation concentration and drying involved in the biotechnology process. Growing cells in alginate beads instead of free cells in a culture medium can answer some of these problems. In this review, the characteristics of the fermentation process based on growing microentrapped (ME) lactic cultures in alginate beads are presented. Potential benefits to nutraceutical and food industries of ME cultures are also presented.


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