Biological Sciences
Lactobacillus
Lactobacillus is a genus of bacteria that is commonly found in the human body, particularly in the digestive system. It is known for its probiotic properties and is often used in the production of fermented foods such as yogurt and sauerkraut. Lactobacillus plays a beneficial role in maintaining the balance of microorganisms in the gut and supporting overall digestive health.
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11 Key excerpts on "Lactobacillus"
- Dongyou Liu(Author)
- 2011(Publication Date)
- CRC Press(Publisher)
257 24.1 INTRODUCTION The genus Lactobacillus belongs to the lactic acid bacte-ria (LAB)group,whichcomprisesabroadlydefinedgram-positive bacterial species of nonspore-forming rods or cocobacilli,andwhichischaracterizedbytheformationof lacticacidasthesoleormainendproductofcarbohydrate metabolism They are catalase-negative, strictly fermenta-tive, aerotolerant or anaerobic, aciduric or acidophilic, and havecomplexnutritionalrequirementsandalowGC(gua-nine+cytosine)content(<50mol%) 1 This genus is one of the most important taxa in food microbiologyandhumanhealthLactobacilli arefoundina varietyofhabitats,whererichcarbohydrate-containingsub-stancesareavailableTheseincludethemucosalmembranes ofhumansandanimals(oralcavity,intestine,andvagina), plantsandmaterialofplantorigin,andman-madehabitats suchassewageandfermentedorspoiledfood Lactobacillus speciesplayacrucialroleintheproductionandpreservation of fermented foods, including vegetables, meats, and dairy products,wheretheyareusedasstarters,adjunctstarters,or protectivecultures 2 Lactobacillus speciesarealsofoundin thehumanthegastrointestinaltractsoonafterbirthSome strainsareconsideredprobiotics,whichconferhealthbenefits totheconsumer,andarecommercializedintheformoffunc-tionalfoodsorfoodsupplements Becauseofthevarietyofhabitatscolonizedby Lactobacillus speciesandtheirimpactonfoodsafety,technology,andhealth, theavailabilityofreliabletoolsfortheirdetectionandidentifica-tionisofutmostimportanceTraditionally,theidentificationof Lactobacillus strainswasbasedonphysiologicalandmetabolic phenotypictraits,suchastheircarbohydratefermentationabil-ityTheseculture-dependentmethodsaretimeconsumingand oftenleadtoerroneousresultsbecauseofthegreatcomplexity andphenotypicvariabilityofthisgenusModerndevelopments inmolecularbiologyandincreasedknowledgeofthegenome sequences of many bacterial groups have turned molecular methods into the most
eBook - PDF- Hati, Subrota(Authors)
- 2021(Publication Date)
- Daya Publishing House(Publisher)
Chapter 8 Lactobacillus reuteri : A Multifaceted Lactic Acid Bacterium for Fermented Foods Santosh Kumar Mishra, R.K. Malik, Amit Kumar and K.K. Mishra Introduction Lactic Acid Bacteria (LAB), comprising about 20 genera, are a heterogeneous group of microorganisms that metabolizes lactose to produce lactic acid. The prominent genera among them are Lactobacillus, Lactococcus, Enterococcus, Streptococcus , Leuconostoc . Since centuries, LAB have been used in industrial and artisanal food fermentations especially as starter cultures and thus, have been playing an important role in the food conservation by the production of a wide variety fermented foods. Furthermore, Elie Metchnikoff in the early 20 th century explored their use as potential probiotics in extending the consumers life in ‘theory of longevity’ (Kimoto et al ., 2007; Ljungh and Wadstrom, 2007). Probiotics are defined as viable microorganisms that exhibit a beneficial effect on human health after ingestion in particular amount by improving its intestinal microbial balance (Fuller 1989; Lee and Salminen 1995). However, there is no widely accepted definition for Probiotics. Recently, FAO/WHO (2002) defined probiotics as, ‘live microorganisms which when administered in adequate amounts confer a health benefit on the host’. During the last two decades probiotic researchers have shown a renewed interest in the health-promoting attributes of LAB and their successful transfer to human beings for their well being. LAB are having Generally-Recognized-as-Safe (GRAS) status, Table 8.1 lists use of L. reuteri as a probiotic in different countries. Amongst all the probiotic This ebook is exclusively for this university only. Cannot be resold/distributed. LAB, genus Lactobacillus , has been most widely used. According to WHO/FAO, a probiotic organism must be isolated from the host source. Members of Lactobacillus genus are most often isolated from the human intestine.
eBook - PDFDairy Microbiology and Biochemistry
Recent Developments
- Barbaros Ozer, Gülsün Akdemir-Evrendilek, Barbaros Ozer, Gülsün Akdemir-Evrendilek, Gulsun Akdemir-Evrendilek, Barbaros Ozer, Gulsun Akdemir-Evrendilek(Authors)
- 2014(Publication Date)
- CRC Press(Publisher)
Recent Advances in Genetics of Lactic Acid Bacteria Ne fi se Akçelik, Ömer Ş im ş ek and Mustafa Akçelik* 3.1 Introduction Lactic acid bacteria (LAB) are a heterogeneous family of microorganisms that can ferment a variety of carbohydrates primarily into lactic acid (Carr et al. 2002). Most of the LAB belongs to the order of Lactobacillales , a group of mainly Gram-positive, anaerobic, non-sporulating and acid-tolerant bacteria. Biochemically, LAB include both homofermenters and heterofermenters (Kleerebezem et al. 2003). The former group produces primarily lactic acid through carbohydrate fermentation, while the latter group yields a variety of fermentation by-products including lactic acid, acetic acid, ethanol, carbon dioxide and formic acid (Leroy and de Vuyst 2004). LAB can be sub-classified into seven phylogenetic clades: Lactococcus, Enterococcus, Oenococcus, Pediococcus, Streptococcus, Leuconostoc and Lactobacillus. The definition of LAB is biological rather than taxonomical, i.e ., the LAB do not comprise a monophyletic group of bacteria. Today, it is known that LAB play a crucial role in the world food supply by performing the main bioconversions in fermented dairy products, meats and vegetables. LAB are also used in the production of wine, coffee, silage, cocoa, sourdough and numerous indigenous food fermentations (Leroy and de Vuyst 2004). LAB are indigenous to food-related habitats including plant (fruits, vegetables and cereal grains) and milk environments. In addition, some LAB species are also member of the flora of the mouth, intestine and vagina of the mammalian (Vaughan et al. 2005). Isolates of the same species are often obtained from plant, dairy and animal habitats, implying wide CHAPTER 3 *Corresponding author Recent Advances in Genetics of Lactic Acid Bacteria Recent Advances in Genetics of Lactic Acid Bacteria 69 distribution and specialized adaptation of these species to these diverse environments.
eBook - ePubBiofungicides: Eco-Safety and Future Trends
Types and Applications, Volume 1
- Kamel A. Abd-Elsalam, Mousa A. Alghuthaymi, Kamel A. Abd-Elsalam, Mousa A. Alghuthaymi(Authors)
- 2023(Publication Date)
- CRC Press(Publisher)
Lactic acid bacteria are said to be one of the most important bacteria in terms of food fermentation, pharmaceuticals and particularly for dietary applications. Lactobacillus, Pediococcus, Aerococcus, Lactococcus, Carnobacterium, Enterococcus, Leuconostoc, Bifidobacterium and Streptococcus are the most often used LAB strains in food. Phylogenetically, LAB belongs to Clostridium branch of gram-positive bacteria, and is catalase negative (although few strains can create pseudo-catalase), acid-tolerant and microaerophilic or anaerobic, with DNA base composition of G+C (Guanine and Cytosine). Morphologically, these are nonsporulating rods and cocci-like microorganisms. LAB was formerly referred to as milk–souring microbes and frequently related to feeding and food loss due to fermentation. However, now these are being recognized as valuable microbes, and some strains are even known to promote health (probiotics). LAB is the most thoroughly studied of all bacteria and used for household purposes and is also used in a wide range of commercial applications, from starter cultures in the dairy industry to probiotics in dietary supplements (Liu et al, 2014). Figure 10.1 depicts a few potential applications of LAB. Fig. 10.1: Potential applications of lactic acid bacteria. 2.1 Lactic acid bacteria: As food preservatives Conscious consumers in modern societies prefer nutritious, fresh and natural foods that are free of artificial preservatives and stabilizers. Lactic acid bacteria are one of the oldest and the most well-known methods for the preservation of food and are generally recognized as safe for human consumption (Korcz and Varga, 2021). The primary strategy used by LAB to outcompete spoilage organisms is the generation of organic acids. However, in recent years, it has been found that LAB uses a number of other mechanisms for eradicating certain food-tainted bacteria (Siedler et al., 2019)
eBook - PDFFermented Foods, Part I
Biochemistry and Biotechnology
- Didier Montet, Ramesh C. Ray, Didier Montet, Ramesh C. Ray(Authors)
- 2016(Publication Date)
- CRC Press(Publisher)
1 Department of Biotechnology, New Horizon College of Engineering, Bangalore, India, 560103. 2 iBET – Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901 Oeiras, Portugal. 3 Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal. * Corresponding author: [email protected] Lactic Acid Bacteria and their Food Applications 113 In this chapter, LAB relevant to food fermentation processes have been evaluated in terms of classification, metabolism, physiology, and applications. Their antimicrobial activities and effect on human health, as well as the products in which they are a fundamental part of the fermentation process, are discussed. 2. Characterizing LAB In the following sections, the classifications and physiology of LAB are discussed in brief. 2.1 The LAB Group LAB comprise an ecologically diverse group of microorganisms united by the formation of lactic acid as the primary metabolite of sugar metabolism (Davis et al. 1986, 1988, Lonvaud-Funel 1999, Liu and Pilone 2000, Liu 2002). They were accepted as a group of bacteria that could be studied together in the first quarter of the 20th century, after the classical publication, ‘ The Butter Aroma Bacteria ’ by Orla-Jensen in 1919 (Orla-Jensen et al. 1926). But, LAB are not a homogenous group. They share a low G + C content (Amann et al. 1995), are Gram-positive, non-spore forming, facultative anaerobic, rod shaped (bacillus), or spherical (coccus) microorganisms (Garvie 1984), with genome sizes that can range from 1.8 to 3.2 Mb (Salvetti et al. 2013, Douillard and de Vos 2014). Acid tolerance ability provides LAB the ability to outcompete other bacteria in a natural fermentation, as they can withstand the increased acidity from organic acid production, a property that makes them important in the final phases of many food fermentation processes, when other microorganisms are inhibited by the low pH.
- Fereidoon Shahidi, Jean-Richard Neeser, J. Bruce German, Fereidoon Shahidi, Jean-Richard Neeser, J. Bruce German(Authors)
- 2004(Publication Date)
- CRC Press(Publisher)
4 Genomics of Probiotic Lactic Acid Bacteria: Impacts on Functional Foods Todd R.Klaenhammer North Carolina State University, Raleigh, North Carolina, U.S.A. Willem M.de Vos Wageningen University and Wageningen Center for Food Sciences, Wageningen, The Netherlands Annick Mercenier Nestlé Research Center, Lausanne, Switzerland I. INTRODUCTION The period since the early 1990s has seen numerous developments aimed at improving the functionality of foods. This can be realized by appropriate selection of raw materials, specific physicochemical processing, or the addition of ingredients (including health- beneficial microorganisms). However, in many cases food functionality can also be enhanced via biological conversions such as by exploiting the activity of lactic acid bacteria or other microbes with a long history of safe use in the food industry. Lactic acid bacteria are used for the industrial production of fermented dairy, vegetable, and meat products and form a group of evolutionarily related low-GC-content gram-positive bacteria, comprising species of Lactobacillus, Lactococcus, or Leuconostoc. Related gram-positive bacteria such as strains of Bacillus subtilis, Enterococcus faecalis, or the somewhat more distantly related (high GC content) Bifidobacterium or Propionibacterium spp. are used for specific food fermentations and can be applied similarly (Fig. 1). Whereas traditionally lactic acid and related bacteria have been applied as starter bacteria, most food innovations of lactic acid and related bacteria are correlated to their use in fermentations with a specific function or the production of ingredients that have potential as nutraceuticals. Yet another important application of these microorganisms is their inclusion as live cells in food and feed matrixes or nutritional complements for the design of health-promoting—probiotic or functional—food products.
eBook - PDF- Edward R.(Ted) Farnworth(Author)
- 2008(Publication Date)
- CRC Press(Publisher)
The only absolute condition for the organisms involved in lactic acid fermentation must be that they produce lactic acid as the major end-product in carbohydrate catabolism and that they are harmless to consume in high numbers, even for consumers with underlying illnesses that weaken their immunological defense. The taxa frequently occurring in high numbers in traditional and spontaneously fermenting lactic acid fermented foods are Lactobacillus , Pediococcus , Weissella , Leuconostoc , Oenococ-cus, Lactococcus , and Streptococcus thermophilus (and some closely related Strep-tococcus species). The genera Lactobacillus , Pediococcus , Leuconostoc , Weissella, and Oenococcus have a relatively close phylogenetic relationship, and might all be included in the trivial expression “lactobacilli.” However, Lactococcus and S. ther-mophilus have from a phylogenic point of view, nothing in common with the lacto-bacilli other than being members of the same general branch of evolution, i.e., the phylum (or division) Firmicutes (Gram-positive bacteria having a relatively low ratio of guanine and cytosine in their genome). 13.3.1.2 Phylogenetic Relationships Lactobacillus plantarum is a bacterial species in the huge and relatively diverse genus of Lactobacillus , which comprises more than 90 validly named species or subspecies. The DNA guanine plus cytosine (G+C) content of the different species ranges from 32 to 54 mol %, which is about twice as large a range as that normally accepted for a well-defined genus. 72–74 By tradition, the Lactobacillus spp. have been divided into three groups depending on their fermentation abilities; the obligately homofermenta-tives (Group I), the facultatively heterofermentatives (Group II), and the obligately heterofermentatives (Group III).
eBook - ePubFermented Foods of Latin America
From Traditional Knowledge to Innovative Applications
- Ana Lucia Barretto Penna, Luis A. Nero, Svetoslav D. Todorov, Ana Lucia Barretto Penna, Luis A. Nero, Svetoslav D. Todorov(Authors)
- 2017(Publication Date)
- CRC Press(Publisher)
15 Novel Biotechnological and Therapeutic Applications for Wild Type and Genetically Engineered Lactic Acid BacteriaRodrigo Dias de Oliveira Carvalho, Fillipe Luiz Rosa do Carmo, Pamela Mancha-Agresti, Marcela Santiago Pacheco de Azevedo, Cassiana Severiano de Sousa, Sara Heloisa da Silva Tessalia Diniz Luerce Saraiva, Mariana Martins Drumond, Bruno Campos Silva and Vasco Ariston de Carvalho Azevedo*AbstractThe human gastrointestinal (GI) tract is colonized by a complex and dense microbial community that can be divided into three major phyla—Bacteroidetes, Firmicutes and Actinobacteria, which, under normal conditions, live in a symbiotic relationship with the host. However, it has been shown that a dysfunctional interaction between the microbiota and the host can lead to several intestinal disorders, thus being considered a field of growing interest by the scientific community. In this context, some studies have been carried out to elucidate functions of true resident bacteria, while other research has attempted to assess transient bacteria. In addition, some studies have focused on the group of lactic acid bacteria (LAB) that are widely used as starter cultures in food fermentation of a large variety of fermented foods. It has being reported that allochthonous LAB bacteria may have positive effects on the host when administrated in adequate amounts, thereby allowing them to be classified as probiotics microorganisms. Our research group recently investigated the mechanisms underlying the protective effects of dairy Lactobacillus delbrueckii Lb CNRZ327 in vitro and in vivo assays and have deposited the complete genome of Lactococcus lactis NCDO 2118, which will enable a greater understanding of its intrinsic characteristics. Beyond the classical employment of LAB, our group gathered research works using genetically engineered LABs, more specifically lactococci and lactobacilli as mucosal delivery vectors for therapeutic proteins and DNA vaccines. In this context, several studies have been conducted to develop new strains and efficient expression systems to use LAB as “cell factories” for the production of anti-inflammatory proteins, where we provide the recombinant Lactococcus lactis
eBook - PDFBiomolecules from Natural Sources
Advances and Applications
- Vijai Kumar Gupta, Satyajit D. Sarker, Minaxi Sharma, Maria Elida Pirovani, Zeba Usmani, Chelliah Jayabaskaran, Vijai Kumar Gupta, Satyajit D. Sarker, Minaxi Sharma, Maria Elida Pirovani, Zeba Usmani, Chelliah Jayabaskaran(Authors)
- 2022(Publication Date)
- Wiley(Publisher)
Biomolecules from Natural Sources: Advances and Applications, First Edition. Edited by Vijai Kumar Gupta, Satyajit D. Sarker, Minaxi Sharma, María Elida Pirovani, Zeba Usmani, and Chelliah Jayabaskaran. © 2022 John Wiley & Sons Ltd. Published 2022 by John Wiley & Sons Ltd. 458 16.1 Introduction The ability of lactic acid bacteria (LAB) to ferment food and beverages has been used since ancient times because of their beneficial influence on nutritional, organoleptic, and shelf-life properties (Deegan et al. 2006; O’Connor et al. 2020). They cause rapid acidification of the raw material through the production of organic acids, mostly lactic and acetic acids; in addition, they can also produce other interesting metabolites such as ethanol, aroma compounds, bacteriocins, exopolysaccharides, hydrogen peroxide, fatty acids, and diverse enzymes. Many of the above mentioned compounds produced by LAB exert antimicrobial activities, which in fermented foods contribute significantly to food biopreservation (De Vuyst and Leroy 2007; Egan et al. 2016). Bacteriocins encompass a large family of ribosomally synthesized antimicrobial pep-tides antagonistic against microorganisms related (competing bacteria) or not (spoilage or pathogenic bacteria) to the producer bacterium (Cotter et al. 2013). Even if both Gram positive and Gram negative bacteria are able to produce bacteriocins, those produced by LAB are of special interest since they have enormous potential in the biopreservation of foods (Dobson et al. 2012). In this sense, the use of bacteriocins from LAB in foods is considered safe for human health (food-grade) since they are produced by LAB generally used for or isolated from fermented foods (Perez et al. 2014). Among the LAB family the higher number of bacteriocin-producer strains belongs to Lactobacillus genera (recently reclassified, Zheng et al. 2020) (31% of the total bacteriocinogenic LAB), followed by Enterococcus (24%) and Streptococcus (17%).
eBook - PDF- Ipek Goktepe, Vijay K. Juneja, Mohamed Ahmedna(Authors)
- 2005(Publication Date)
- CRC Press(Publisher)
Clearly, the name “ Lactobacillus sporogenes ” has no scientific validity, but it is still in use in several labels of probiotic products (Sanders et al., 2003). In addition, recent surveys on the identification of spore-forming probiotic bacteria have shown that in a relevant number of cases, nomenclature of bacteria used for labeling is incorrect or out of date (Hamilton-Miller et al., 1999). Ambiguous nomenclature has plagued not only probiotic bacteria but also yeast. An example is Saccharomyces boulardii, a well-studied yeast used as a probiotic for humans and animals and supported by a robust scientific liter-ature. This probiotic has been used in several clinical trials and has been included as a positive example of the action of probiotics in several meta-analyses (Cremonini et al., 2002; D'Souza et al., 2002), but its allotment to a specific taxonomic group has been achieved only recently by means of molec-ular biology techniques, which suggest that this organism could be included in S. cerevisiae ( Mitterdorfer et al., 2002; Hennequin et al., 2001; Dujon, 2001) It is also of note that several products that are on the market and claim to contain “bifid” bacteria, report on their labels the presence of bacteria named according to very old nomenclature, no longer accepted by the scientific community. Several papers have been published on this matter, and they point out the use of old names such as “ Lactobacterium bifidum ” or “ Lactoba-cillus bifidum ,” ignoring the existence of a genus called “ Bifidobacterium ”. On the other hand, the same authors note the presence of lactobacilli misclassi-fied as L. acidophilus but belonging to one of the six species obtained in 1980 by DNA-DNA analysis of strains phenotypically identified as L.
- Sabu Thomas, Rajendran Rajakumari, Anne George, Nandakumar Kalarikkal, Sabu Thomas, Rajendran Rajakumari, Anne George, Nandakumar Kalarikkal(Authors)
- 2018(Publication Date)
- Apple Academic Press(Publisher)
Streptococcus , have traditionally been used in fermented dairy products to promote human health as well as food functionality and flavor.Metchnikoff first introduced the probiotic concept in 1908, which observed the long life of Bulgarian peasants, who consumed fermented milk foods. He suggested that lactobacilli might counteract the putrefactive effects of gastrointestinal metabolism. In this century, which is elapsed since Metchnikoff’s research, scientists and consumers have accepted the probiotic concept throughout the world (Fuller, 1992 ). The longevity of Caucasians was related to the high intake of fermented milk products Metchnikoff (1907 ), as elucidated in his bestselling book The Prolongation of Life. Lactic acid bacteria (LAB) belongs to a group of Gram-positive, non-sporulating, non-respiring cocci, or rods, which produce lactic acid as a major metabolic end product during the fermentation of carbohydrates (Salminen et al., 1998 ). In the world, the concept of providing functional foods including beneficial components rather than removing potentially harmful components is gaining ground in recent years. It may consider a functional food with the special property of containing live, beneficial microorganisms. Functional foods and nutraceutical can prevent and treat diseases. Yogurt and other fermented milk containing probiotics may be considered the first functional foods. The increasing cost of healthcare, the steady increase in life expectancy and the desire of the elderly for improved quality of their lives are driving factors for research and development in the area of functional foods. Although the concept of functional foods was introduced long ago with Hippocrates and his motto “Let food be your medicine,” fairly recently the body of evidence started to support the hypothesis that diet may play an important role in modulation of important physiological functions in the body. Among a number of functional compounds recognized so far, bioactive components from fermented foods and probiotics certainly take the center stage due to their long tradition of safe use and established and postulated beneficial effects. The first clinical trials in the 1930s focused on the effect of probiotics on constipation and research has steadily increased since then. Today, probiotics are available in a variety of food products and supplements. Food products containing probiotics are mostly dairy products due to the historical association of lactic acid bacteria with fermented milk. The fermentation of dairy foods presents one of the oldest methods of long-term food preservation. The origin of fermented milk can be traced back long before the Phoenician era and placed in the Middle East. Traditional Egyptian fermented milk products, Laban Rayeb and Laban Khad, were consumed as early as 7000 BC. Their tradition claims that even Abraham owed his longevity to the consumption of cultured milk (Kosikowski & Mistry, 1997 ). Initially, established in the middle and far east of Asia, the tradition of fermenting milk was spread throughout the east Europe and Russia by the Tartars, Huns, and Mongols during their conquests. As a consequence, a wide range of fermented dairy products still exists in these regions and some popular products such as yogurt and kefir are claimed to originate from the Balkans and Eastern Europe (Azizpour et al., 2009
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