Influence of Mutagenic Chemicals on Fermentative production of Lactic Acid by Lactobacillus delbrueckii

Author(s):  
K.P. Tiwari ◽  
S.P. Singh
2012 ◽  
Vol 3 (1) ◽  
pp. 23-32 ◽  
Author(s):  
A. Do Carmo ◽  
M. De Oliveira ◽  
D. Da Silva ◽  
S. Castro ◽  
A. Borges ◽  
...  

There are three main reasons for using lactic acid bacteria (LAB) as starter cultures in industrial food fermentation processes: food preservation due to lactic acid production; flavour formation due to a range of organic molecules derived from sugar, lipid and protein catabolism; and probiotic properties attributed to some strains of LAB, mainly of lactobacilli. The aim of this study was to identify some genes involved in lactose metabolism of the probiotic Lactobacillus delbrueckii UFV H2b20, and analyse its organic acid production during growth in skimmed milk. The following genes were identified, encoding the respective enzymes: ldh – lactate dehydrogenase, adhE – Ldb1707 acetaldehyde dehydrogenase, and ccpA-pepR1 – catabolite control protein A. It was observed that L. delbrueckii UFV H2b20 cultivated in different media has the unexpected ability to catabolyse galactose, and to produce high amounts of succinic acid, which was absent in the beginning, raising doubts about the subspecies in question. The phylogenetic analyses showed that this strain can be compared physiologically to L. delbrueckii subsp. bulgaricus and L. delbrueckii subsp. lactis, which are able to degrade lactose and can grow in milk. L. delbrueckii UFV H2b20 sequences have grouped with L. delbrueckii subsp. bulgaricus ATCC 11842 and L. delbrueckii subsp. bulgaricus ATCC BAA-365, strengthening the classification of this probiotic strain in the NCFM group proposed by a previous study. Additionally, L. delbrueckii UFV H2b20 presented an evolutionary pattern closer to that of probiotic Lactobacillus acidophilus NCFM, corroborating the suggestion that this strain might be considered as a new and unusual subspecies among L. delbrueckii subspecies, the first one identified as a probiotic. In addition, its unusual ability to metabolise galactose, which was significantly consumed in the fermentation medium, might be exploited to produce low-browning probiotic Mozzarella cheeses, a desirable property for pizza cheeses.


REAKTOR ◽  
2017 ◽  
Vol 5 (2) ◽  
pp. 79
Author(s):  
Abdullah Abdullah ◽  
H. B. Mat

The liquid pineapple waste contain mainly sucrose, glucose, fructose, and other nutrients. It therefore can potentiall be used as carbon source for organic acid fermentation. Recently, lactic acid has been considered to be an important raw material for production of biodegradadable lactace polymer. The experiments weree carried out in shake flash fermentation using lactobacillus delbroeckii. Effect of some parameters such as temperature, initial Ph, initial substrate concentration, yeast extract concentration and fermentation time to the yield have been studied. The highest yield was 85.65% achieved at 40 0C, PH 6.00, 52.2 g/l sugar concentration with 5 g/l yeast extract. There was no significant increasing in lactic acid production was observed if supplementation of yeast extract above 10%.Keyword : lactic acid fermentation, liquid pineapple waste, lactobacillus delbrueckii


TABLE 3 Major Commercial Fermentation Conditions for Cereal Foods Fermentation conditions Bread Beer Whiskey Soy sauce Miso Main starters Baker's yeast Brewer's yeast Distillery yeast Molds Molds (Saccharomyces (Saccharomyces (Saccharomyces (Aspergillus spp.) (Aspergillus spp.) cerevisiae) cerevisiae) cerevisiae) Saccharomyces rouxii Lactic acid bacteria Lactobacillus delbrueckii Cereals Milled wheat Barley (malted) Corn Soybeans (defatted) Rice Milled rye Sorghum Rye (malted or not) Wheat Barley Minor: Minor: Barley (malted) Minor: Soybeans Barley (malted) Corn Wheat Barley flour Wheat (malted) Rice Wheat Other ingredients Water Water Water Water Salt Salt Hops Salt Hot pepper Sugar Adjuncts Fat (corn syrup, sugar Emulsifiers or starch) Dough strengtheners Preservatives Enzymes Fermentation 1-6h2-10 days 2-3 days (Koji: 3 days at 30°C) (Koji: 2 days at 30°C) conditions 20-42°C 3-24°C 32-35°C 3-12 months 2 days to 1 year Aging: Aging: 15-30°C 30-50°C 3 days-1 month 2-3 years or more 0-13°C 21-30°C baker's yeast is probably the most common of these microorganisms that may be a problem are bacteria (usual-starters; it is commercially produced in liquid, paste (com-ly spore-forming or lactic acid bacteria, especially in some pressed), or dry form. Recently, commercial lactic acid yeast fermentations), wild yeasts, and molds. bacteria starters have been introduced for cereal fermenta-Several spore-forming bacteria (e.g., Bacillus spp.) may tions, but this application is less frequent than their regular produce amylases and degrade hydrated starchy materials. use in dairy or meat fermentations. A close control of the In bread, heat-tolerant spores of Bacillus subtilis (formerly performance of commercial starters is important, since it Bacillus mesentericus) survive the baking process; after a has a major effect on the final products. few days in bread, they produce a spoilage called ropiness, characterized by yellow spots on crumb, putrid pineapple aroma, and stringiness when breaking a piece of bread. The spores of these species, when contaminating flour, may Considering the diversity of the microbial flora that may cause a major problem in bakeries since they are highly re-be present in cereals to be fermented, undesirable microor-sistant in the environment and difficult to eliminate. How-ganisms are likely to be part of this flora and may produce ever, these bacterial infections have become rare in recent problems in the main fermentation process with subse-years, presumably due to improved sanitation. In beer, un-quent adverse effects on the final product. Nowadays these desirable microbial contamination is exhibited by viscosity, problems are lessened by good sanitary practices. Sources appearance, as well as aroma and flavor problems. of these organisms may be the cereals themselves, soil, as Microbial pathogens are usually not a problem for fer-well as any particular ingredient, surface contamination, mented cereals because of the inhibition brought about by and unsanitary handling. acids and ethanol generated by fermenting organisms. A Table 4 summarizes microbial problems likely to occur large proportion of fermented cereals are also eaten shortly during major cereal fermentations. In general, undesirable after complete cooking. However, the biggest problem


2018 ◽  
Vol 6 (2) ◽  
pp. 500-508
Author(s):  
Julie Ann A. Arcales ◽  
Garner Algo L.Alolod

Isolation and characterization of bacteria in food products are important to determine and distinguish the beneficial or harmful effects of microbiota in certain samples. Lactic acid bacteria in food products had long been associated to good factors as food preservatives and with added fermentation metabolites. This study isolated and characterized lactic acid bacteria from burong bangus. The culture and purification process of bacteria isolation resulted to 4 strains of lactic acid bacteria namely Enterococcus faecalis, Tetragenococcus muriaticus, Lactobacillus delbrueckii subp. delbrueckii and Carnobacterium divergens. High enzymatic activity were observed with E. faecalis particularly on lipase and protease assay. While C. divergens have no enzymatic activity against lipase, protease, amylase and cellulase. The antimicrobial property of L. delbrueckii is only susceptible to amoxicillin unlike the other three bacteria isolates. No antagonistic activity were observed with the four bacterial strains against Bacillus subtilis, Staphylococcus aureus and Escherichia coli. The result of this study showed promising benefits to the industry especially in developing countries like the Philippines because population are not yet so aware of this organisms and the benefits that can be derived through their consumption.


2021 ◽  
Author(s):  
Shuai Zhang ◽  
Dongyao Li ◽  
Xin Zhang ◽  
Yongsheng Sun ◽  
Sha Xu ◽  
...  

During the storage of yogurt, acid-resistant bacteria continue to produce lactic acid (i.e., post-acidification process), leading to undesirable taste and flavor. Many methods have been proposed to inhibit post-acidification. However,...


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