Novel Biotechnological and Therapeutic Applications for Wild Type and Genetically Engineered Lactic Acid Bacteria

2017 ◽  
pp. 307-336
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Genetically Engineered ◽  
Wild Type ◽  
Therapeutic Applications

scholarly journals Use of the alr Gene as a Food-Grade Selection Marker in Lactic Acid Bacteria

2002 ◽  
Vol 68 (11) ◽  
pp. 5663-5670 ◽  
Author(s):  
Peter A. Bron ◽  
Marcos G. Benchimol ◽  
Jolanda Lambert ◽  
Emmanuelle Palumbo ◽  
Marie Deghorain ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Competitive Inhibitor ◽  
Selection Marker ◽  
Wild Type ◽  
Gene Encoding ◽  
Food Grade ◽  
Selection For ◽  
Isogenic Mutants ◽  
Type Strains

ABSTRACT Both Lactococcus lactis and Lactobacillus plantarum contain a single alr gene, encoding an alanine racemase (EC 5.1.1.1), which catalyzes the interconversion of d-alanine and l-alanine. The alr genes of these lactic acid bacteria were investigated for their application as food-grade selection markers in a heterologous complementation approach. Since isogenic mutants of both species carrying an alr deletion (Δalr) showed auxotrophy for d-alanine, plasmids carrying a heterologous alr were constructed and could be selected, since they complemented d-alanine auxotrophy in the L. plantarum Δalr and L. lactis Δalr strains. Selection was found to be highly stringent, and plasmids were stably maintained over 200 generations of culturing. Moreover, the plasmids carrying the heterologous alr genes could be stably maintained in wild-type strains of L. plantarum and L. lactis by selection for resistance to d-cycloserine, a competitive inhibitor of Alr (600 and 200 μg/ml, respectively). In addition, a plasmid carrying the L. plantarum alr gene under control of the regulated nisA promoter was constructed to demonstrate that d-cycloserine resistance of L. lactis is linearly correlated to the alr expression level. Finally, the L. lactis alr gene controlled by the nisA promoter, together with the nisin-regulatory genes nisRK, were integrated into the chromosome of L. plantarum Δalr. The resulting strain could grow in the absence of d-alanine only when expression of the alr gene was induced with nisin.

Emergence of Probiotics in Therapeutic Applications

2009 ◽  
Vol 2 (1) ◽  
pp. 383-389
Author(s):  
Barun K Bhattacharyya
Keyword(s):  
Health Care ◽  
Lactic Acid ◽  
Gastrointestinal Tract ◽  
Lactic Acid Bacteria ◽  
Functional Foods ◽  
Saccharomyces Boulardii ◽  
Lactobacillus Species ◽  
Therapeutic Applications ◽  
Probiotic Strains ◽  
Good Number

The gastrointestinal tract of human body is considered as an ecosystem which had been developed physiologically and microbiologically. The probiotic organisms (lactic acid bacteria) are one of the most important groups present in the gastrointestinal tract. A good number of Lactobacillus species, Bifidobacterium species, Saccharomyces boulardii and some other microbes are now used as probiotic strains. These probiotic organisms are marketed as health care products, functional foods or food supplements. The details of clinical, therapeutic applications and safety aspects of probiotics are discussed.

Immunomodulating effects of milks fermented by Lactobacillus helveticus and its non-proteolytic variant

2001 ◽  
Vol 68 (4) ◽  
pp. 601-609 ◽  
Author(s):  
CHANTAL MATAR ◽  
JUAN CARLOS VALDEZ ◽  
MARCELA MEDINA ◽  
MIRTHA RACHID ◽  
GABRIELA PERDIGON
Keyword(s):  
Immune Response ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Lymphoid Tissue ◽  
Peritoneal Macrophages ◽  
Lactobacillus Helveticus ◽  
Cellular Migration ◽  
Direct Immunofluorescence ◽  
Wild Type ◽  
Number Of Cells

The effect of milks fermented by Lactobacillus helveticus and its non-proteolytic variant on mucosal and tumoral immunity was studied. Milks fermented by Lb. helveticus wild type or its non-proteolytic variant were administered orally to mice for different periods (3, 5 and 7 d). The immune response was assessed by analysing the activity of the peritoneal macrophages, the number of cells secreting IgA associated with the gut-associated lymphoid tissue and with the bronchial-associated lymphoid tissue. The number of cells was determined by direct immunofluorescence. The antitumour activity was monitored by studying the regression of the subcutaneously implanted fibrosarcomas. After 3 d feeding of milk fermented by Lb. helveticus wild type, the number of sIgA increased significantly at both the intestinal and bronchial levels, indicating that a cellular migration had occurred. This effect was not noticeable when milk fermented by Lb. helveticus Protease (−) was orally administered. Both fermented milks (wild type or its variant) exhibited an effect on the activity of the peritoneal macrophages, which might be indirectly correlated to the regression of the fibrosarcoma. Although the mechanism by which the lactic acid bacteria enhance the immune system is not clear, this study clearly suggests that the bioactive compounds released during milk fermentation might contribute to the immunoenhancing properties of these products. By releasing biopeptide, lactic acid bacteria have important implications in modulation of the host's immune response, more specifically its cellular immune response.

Recombinant lactic acid bacteria as delivery vectors of heterologous antigens: the future of vaccination?

2015 ◽  
Vol 6 (3) ◽  
pp. 313-324 ◽  
Author(s):  
A. Trombert
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Bacterial Infections ◽  
Molecular Design ◽  
Oral Vaccines ◽  
Molecular Tools ◽  
Wild Type ◽  
Antimicrobial Substances ◽  
Heterologous Antigens ◽  
Lactobacillus Spp

Lactic acid bacteria (LABs) are good candidates for the development of new oral vaccines and are attractive alternatives to attenuated pathogens. This review focuses on the use of wild-type and recombinant lactococci and lactobacilli with emphasis on their molecular design, immunomodulation and treatment of bacterial infections. The majority of studies related to recombinant LABs have focused on Lactococcus lactis, however, molecular tools have been successfully used for Lactobacillus spp. research. Recombinant lactobacilli and lactococci have several health benefits, such as immunomodulation, restoration of the microbiota, synthesis of antimicrobial substances and inhibition of virulence factors. In addition, protective immune responses that are well tolerated are induced by the expression of heterologous antigens from recombinant probiotics.

scholarly journals Extracellular Proteolytic Activity and Amino Acid Production by Lactic Acid Bacteria Isolated from Malaysian Foods

2019 ◽  
Vol 20 (7) ◽  
pp. 1777 ◽  
Author(s):  
Cui Jin Toe ◽  
Hooi Ling Foo ◽  
Teck Chwen Loh ◽  
Rosfarizan Mohamad ◽  
Raha Abdul Rahim ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Genetically Engineered ◽  
Pediococcus Acidilactici ◽  
Producer Strain ◽  
Pediococcus Pentosaceus ◽  
Genetically Engineered Microorganisms ◽  
Protein Molecules ◽  
Proteolytic Activities ◽  
Ph Conditions

Amino acids (AAs) are vital elements for growth, reproduction, and maintenance of organisms. Current technology uses genetically engineered microorganisms for AAs production, which has urged the search for a safer food-grade AA producer strain. The extracellular proteolytic activities of lactic acid bacteria (LAB) can be a vital tool to hydrolyze extracellular protein molecules into free AAs, thereby exhibiting great potential for functional AA production. In this study, eight LAB isolated from Malaysian foods were determined for their extracellular proteolytic activities and their capability of producing AAs. All studied LAB exhibited versatile extracellular proteolytic activities from acidic to alkaline pH conditions. In comparison, Pediococcus pentosaceus UP-2 exhibited the highest ability to produce 15 AAs extracellularly, including aspartate, lysine, methionine, threonine, isoleucine, glutamate, proline, alanine, valine, leucine, tryptophan, tyrosine, serine, glycine, and cystine, followed by Pediococcus pentosaceus UL-2, Pediococcus acidilactici UB-6, and Pediococcus acidilactici UP-1 with 11 to 12 different AAs production detected extracellularly. Pediococcus pentosaceus UL-6 demonstrated the highest increment of proline production at 24 h of incubation. However, Pediococcus acidilactici UL-3 and Lactobacillus plantarum I-UL4 exhibited the greatest requirement for AA. The results of this study showed that different LAB possess different extracellular proteolytic activities and potentials as extracellular AA producers.

scholarly journals A Novel Bacteriophage Exclusion (BREX) System Encoded by the pglX Gene in Lactobacillus casei Zhang

2019 ◽  
Vol 85 (20) ◽  
Author(s):  
Wenyan Hui ◽  
Wenyi Zhang ◽  
Lai-Yu Kwok ◽  
Heping Zhang ◽  
Jian Kong ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Restriction Endonuclease ◽  
Lactobacillus Casei ◽  
System Component ◽  
Wild Type ◽  
Exogenous Dna ◽  
Content Type ◽  
Recognition Sites ◽  
Significant Difference

ABSTRACT The bacteriophage exclusion (BREX) system is a novel prokaryotic defense system against bacteriophages. To our knowledge, no study has systematically characterized the function of the BREX system in lactic acid bacteria. Lactobacillus casei Zhang is a probiotic bacterium originating from koumiss. By using single-molecule real-time sequencing, we previously identified N6-methyladenine (m6A) signatures in the genome of L. casei Zhang and a putative methyltransferase (MTase), namely, pglX. This work further analyzed the genomic locus near the pglX gene and identified it as a component of the BREX system. To decipher the biological role of pglX, an L. casei Zhang pglX mutant (ΔpglX) was constructed. Interestingly, m6A methylation of the 5′-ACRCAG-3′ motif was eliminated in the ΔpglX mutant. The wild-type and mutant strains exhibited no significant difference in morphology or growth performance in de Man-Rogosa-Sharpe (MRS) medium. A significantly higher plasmid acquisition capacity was observed for the ΔpglX mutant than for the wild type if the transformed plasmids contained pglX recognition sites (i.e., 5′-ACRCAG-3′). In contrast, no significant difference was observed in plasmid transformation efficiency between the two strains when plasmids lacking pglX recognition sites were tested. Moreover, the ΔpglX mutant had a lower capacity to retain the plasmids than the wild type, suggesting a decrease in genetic stability. Since the Rebase database predicted that the L. casei PglX protein was bifunctional, as both an MTase and a restriction endonuclease, the PglX protein was heterologously expressed and purified but failed to show restriction endonuclease activity. Taken together, the results show that the L. casei Zhang pglX gene is a functional adenine MTase that belongs to the BREX system. IMPORTANCE Lactobacillus casei Zhang is a probiotic that confers beneficial effects on the host, and it is thus increasingly used in the dairy industry. The possession of an effective bacterial immune system that can defend against invasion of phages and exogenous DNA is a desirable feature for industrial bacterial strains. The bacteriophage exclusion (BREX) system is a recently described phage resistance system in prokaryotes. This work confirmed the function of the BREX system in L. casei and that the methyltransferase (pglX) is an indispensable part of the system. Overall, our study characterizes a BREX system component gene in lactic acid bacteria.

scholarly journals Mechanisms Involved in the Anti-Inflammatory Properties of Native and Genetically Engineered Lactic Acid Bacteria

2012 ◽  
Vol 11 (1) ◽  
pp. 59-69 ◽  
Author(s):  
Jean LeBlanc ◽  
Silvina Carmen ◽  
Meritxell Turk ◽  
Fernanda Lima ◽  
Daniela Pontes ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Genetically Engineered ◽  
Anti Inflammatory

scholarly journals Ribosome-Engineered Lacticaseibacillus rhamnosus Strain GG Exhibits Cell Surface Glyceraldehyde-3-Phosphate Dehydrogenase Accumulation and Enhanced Adhesion to Human Colonic Mucin

2020 ◽  
Vol 86 (20) ◽  
Author(s):  
Minori Ishida ◽  
Fu Namai ◽  
Suguru Shigemori ◽  
Shoko Kajikawa ◽  
Masami Tsukagoshi ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Cell Surface ◽  
Protein Transport ◽  
Breeding Strategy ◽  
Wild Type ◽  
Resistance Mutations ◽  
Ribosome Engineering ◽  
Colonic Mucin ◽  
Probiotic Lactic Acid Bacteria

ABSTRACT Differences in individual host responses have emerged as an issue regarding the health benefits of probiotics. Here, we applied ribosome engineering (RE) technology, developed in an actinomycete study, to Lacticaseibacillus rhamnosus GG (LGG). RE can effectively enhance microbial potential by using antibiotics to induce spontaneous mutations in the ribosome and/or RNA polymerase. In this study, we identified eight types of streptomycin resistance mutations in the LGG rpsL gene, which encodes ribosomal protein S12. Notably, LGG harboring the K56N mutant (LGG-MTK56N) expressed high levels of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) on the cell surface compared with the LGG wild type (LGG-WT). GAPDH plays a key role in colonic mucin adhesion. Indeed, LGG-MTK56N significantly increased type A human colonic mucin adhesion compared to LGG-WT in experiments using the Biacore system. The ability to adhere to the colon is an important property of probiotics; thus, these results suggest that RE is an effective breeding strategy for probiotic lactic acid bacteria. IMPORTANCE We sought to apply ribosome engineering (RE) to probiotic lactic acid bacteria and to verify RE’s impact. Here, we showed that one mutant of RE Lacticaseibacillus rhamnosus GG (LGG-MTK56N) bore a GAPDH on the cell surface; the GAPDH was exported via an ABC transporter. Compared to the wild-type parent, LGG-MTK56N adhered more strongly to human colonic mucin and exhibited a distinct cell size and shape. These findings demonstrate that RE in LGG-MTK56N yielded dramatic changes in protein synthesis, protein transport, and cell morphology and affected adherence to human colonic mucin.

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