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The proteolytic system of Lactobacillus bulgaricus breaks down milk proteins into peptides and amino acids, which are essential for the growth of the bacteria. The aim of this study was to determine the expressions of seven key genes in the proteolytic system under different culturing conditions (different phases, initial pH values, temperatures, a...
Citations
... The production of bioactive peptides (B.A.P.s) is carried out by proteolytic microorganisms, predominantly Bacillus, during the process of food fermentation (Mejia and Dia, 2010;Nagai and Tamang, 2010). Peptides exhibit certain properties related to antihypertension (Phelan and Kerins 2011) and also serve as crucial functional agents with antithrombotic (Hou et al., 2015) and immunomodulatory roles (Alcantara et al., 2016). However, the production of B.A.P.s is still below the required level because there are no large-scale production facilities and the cost of protein hydrolysis enzymes is rising. ...
... First, 10 putative protease encoding genes, including the cell wall protease prtB gene (LDD865_V1_0941), were identified ( Table 2). The serine proteinase PrtB is implicated in the degradation of milk proteins into peptides in dairy fermentations and is found in other strains and LAB species (36)(37)(38). The peptides released by PrtB can then be taken up by two oligopeptide transport systems belonging to the ABC transporter family, oppAA2BCDD1F (named opp1, from LDD865_v1_0763 to LDD865_v1_0770) and oppAA2BCDF (named opp2, from LDD865_v1_1722 to LDD865_v1_1731), as previously described for other LABs. ...
In the context of sustainable diet, the development of soy-based yogurt fermented with lactic acid bacteria is an attractive alternative to dairy yogurts. To decipher the metabolism of Lactobacillus delbrueckii subsp. delbrueckii during soy juice (SJ) fermentation, the whole genome of the strain CIRM-BIA865 ( Ld 865) was sequenced and annotated. Then Ld 865 was used to ferment SJ. Samples were analyzed throughout fermentation for their cell number, carbohydrate, organic acid, free amino acid, and volatile compound contents. Despite acidification, the number of Ld 865 cells did not rise, and microscopic observations revealed the elongation of cells from 3.6 µm (inoculation) to 36.9 µm (end of fermentation). This elongation was observed in SJ but not in laboratory-rich medium MRS. Using transcriptomic analysis, we showed that the biosynthesis genes of peptidoglycan and membrane lipids were stably expressed, in line with the cell elongation observed, whereas no genes implicated in cell division were upregulated. Among the main sugars available in SJ (sucrose, raffinose, and stachyose), Ld 865 only used sucrose. The transcriptomic analysis showed that Ld 865 implemented the two transport systems that it contains to import sucrose: a PTS system and an ABC transporter. To fulfill its nitrogen needs, Ld 865 probably first consumed the free amino acids of the SJ and then implemented different oligopeptide transporters and proteolytic/peptidase enzymes. In conclusion, this study showed that Ld 865 enables fast acidification of SJ, despite the absence of cell division, leads to a product rich in free amino acids, and also leads to the production of aromatic compounds of interest.
IMPORTANCE
To reduce the environmental and health concerns related to food, an alternative diet is recommended, containing 50% of plant-based proteins. Soy juice, which is protein rich, is a relevant alternative to animal milk, for the production of yogurt-like products. However, soy “beany” and “green” off-flavors limit the consumption of such products. The lactic acid bacteria (LAB) used for fermentation can help to improve the organoleptic properties of soy products. But metabolic data concerning LAB adapted to soy juice are lacking. The aim of this study was, thus, to decipher the metabolism of Lactobacillus delbrueckii subsp. delbrueckii during fermentation of a soy juice, based on a multidisciplinary approach. This result will contribute to give tracks for a relevant selection of starter. Indeed, the improvement of the organoleptic properties of these types of products could help to promote plant-based proteins in our diet.
... It is important to note that the Ami system can transport peptides with up to 23 amino acids, whereas the Dpp system of Lactococcus or Lactobacillus can only transport chains with fewer than 13 amino acids. The last one, 3): peptide breakdown by intracellular peptidases, three of which are unique to S. thermophilus and are capable of either releasing aromatic amino acids or peptides containing aromatic amino acids [11,[60][61][62]. Also, several studies have been reported various CEPEs from LAB genomes in genera of Lactobacillus sp., including (prtB) from bulgaricus subsp. ...
... Also, several studies have been reported various CEPEs from LAB genomes in genera of Lactobacillus sp., including (prtB) from bulgaricus subsp. bulgaricus [60], (prtP) from L. casei or L. paracasei [61], (prtR) from L. rhamnosus [13], and (prtH) from L. helveticus [62]. These results are consistent with those of other studies and suggests that CEPEs start the hydrolysis of proteins by cleaving them into bioactive peptides of 4 to 30 amino acids, those peptides possess antioxidative and/or antimicrobial properties. ...
The demand for healthy food items with a high nutrient value of bioavailability and bioaccessibility has created a need for continuous development of technology and food ingredients like bioactive peptides. This study aimed to investigate seven proteolytic lactic acid bacteria (PLABs) isolated from the plaa-som (fermented fish) sample originated from silver BARB species for production of proteolytic enzymes. Proteolytic enzymes produced by (PLABs) were used further to create potent bioactive peptides by hydrolyzing proteins throughout PLAB-probiotics enhancer. Protein derived-bioactive peptides was tested the proteolytic activity on different protein sources and examined bioactivities including antioxidative and antimicrobial effect for further use in functional foods. Results of screened-PLAB strains showed high proteolytic activity namely Streptococcus thermophilus strains (KKUPA22 and KKUPK13). These strains have proteolytic system consisting of extracellular and cell-bound enzymes that used for degrading protein in fish flesh protein (FFP) and skim milk (SKM) broth media. Proteolytic activity of tested bacterial enzymes was estimated after incubation at 45, 37, and 50 °C. Furthermore, FFP hydrolysates were formed with various peptides and has small molecular weights (checked by SDS-PAGE) in the range of10.5 to 22 kDa), exhibiting strong activity. Data revealed that S. thermophilus strains (KKUPA22 and KKUPK13) had high antioxidant activity in term of 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azinobis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS) radical-scavenging inhibition, and ferric reducing antioxidant power (FRAP) reducing power capacity. Both strains (KKUPA22 and KKUPK13) of S. thermophilus have higher antimicrobial activity against Gram-negative bacteria than against Gram-positive bacteria. We have confirmed presence of proteolytic (prt) gene regions in S. thermophilus strains using specific primers via PCR amplification. Results showed highest homology (100%) with the prtS gene of S. thermophillus located on the cell envelope proteolytic enzymes (CEPEs) such as serine proteinase. Therefore, it concluded that the proteolytic system of tested PLAB strains able to generate bioactive peptides-derived proteins having active biological property, good mechanism of degradability, and bioaccessibility for further use in catalyzing protein of functional foods.
... Сүүний уургийн задралын дүнд сүүн хүчлийн бактерийн протеолитик энзимийн нөлөөгөөр биологийн идэвхт пептидүүд үүсэх [11,22,23] ба сүүний уургийн гаралтай пептидүүд хүнс тэжээлийн ач холбогдолтойгоос гадна дархлаа дэмжих, цусны даралт бууруулах, бактерийн эсрэг үйлчлэх, исэлдэлтийн эсрэг идэвх үзүүлэх зэрэг биологийн олон чухал үйлчлэл үзүүлдэг [21,22]. Бид энэхүү судалгаагаар протеолитик идэвхтэй Lactobacillus plantarum, Lactobacillus fermentum, Streptococcus thermophilus, Lactobacillus kefiri 4 зүйлийн сүүн хүчлийн бактерийг ялган авсан ба тус зүйлүүдийн протеолитик идэвхийн судалгааг БНХАУ (Jin-cai, 2015), Австралийн (Donkor, 2006) эрдэмтэд тодорхойлж байжээ [23,24]. Jivka (2014), Jin-cai (2015) нарын судалгаагаар сүүн хүчлийн бактерийн протеолитик идэвх ферментацийн 0-12 цагийн хугацаанд чөлөөлөгдсөн амин хүчлийн хэмжээ 0.01-0.50 ...
Lactic acid bacteria produce various biologically active molecules such as low molecular weight proteins, small peptides and free amino acids during their life cycle. The small peptides have many critical biological functions: immune support, lowering blood pressure, antibacterial activity, and antioxidant activity etc. In this study, 18 lactic acid bacteria were isolated from traditional milk products. The study of all strains was carried out using morphological and biochemical methods. The proteolytic activity of lactic acid bacteria was determined by milk agar diffusion and the OPA method. From the results, D3-1, D13-1, A19-7, and A19-9 strains displayed 4-10 mm clear zone on the skim milk agar and produced 1338 - 1872 mM of free amino acids. These strains inhibited cell growth of five different gram-positive and -negative pathogenic bacteria. We also examined four isolates that exhibited potent antioxidant and probiotic activities. Based on the biological activities selected, four lactic acid bacteria were identified by sequencing of 16S rRNA gene analysis; Lactobacillus plantarum (98.76%), Lactobacillus fermentum (99.42%), Streptococcus thermophilus (99.90%), Lactobacillus kefiri (98.04%), respectively. Уламжлалт сүүн бүтээгдэхүүнээс ялгасан сүүн хүчлийн бактерийн биологийн идэвхийн судалгаа Хураангуй Сүүн хүчлийн бактериуд амьдралын үйл ажиллагааны дүнд олон төрлийн биологийн идэвхт бодисын солилцооны бүтээгдэхүүнүүдийг үүсгэж байдаг. Жишээ нь, сүүн хүчлийн бактерийн протеолитик энзимийн нөлөөгөөр сүүний уургийн задралын дүнд үүсдэг бага молекулт уураг, пептидүүд дархлаа дэмжих, цусны даралт бууруулах, бактерийн эсрэг үйлчлэх, исэлдэлтийн эсрэг идэвх үзүүлэх зэрэг биологийн олон чухал үйлчлэл үзүүлдэг. Энэхүү судалгаагаар уламжлалт аргаар бэлтгэсэн гүүний айраг, сарлагийн сүү, сүүн бүтээгдэхүүнээс сүүн хүчлийн бактери байх магадлалтай нийт 18 цэвэр өсгөврийг ялгаж, биологийн идэвхийг тодорхойлов. Сүүн хүчлийн бактериудын протеолитик идэвхийг сүүний казейн задлах идэвх болон ОРА аргаар тодорхойлоход D3-1, D13-1, A19-7, A19-9 өсгөврүүд сүүтэй агарт 4-10 мм тунгалаг зон, 1338 – 1872 ммоль/л чөлөөт амин хүчлийг үүсгэж байв. Бактерийн эсрэг идэвхийг шалгахад D3-1, D6-1, A19-6, A19-7 өсгөврүүд грам эерэг болон сөрөг 5 өөр зүйлийн өвчин үүсгэгчийн өсөлтийг хүчтэй дарангуйлж байсан бол дээрх өсгөврүүд DPPH чөлөөт радикалыг 56.67-86.64% дарангуйлах идэвхтэй болохыг илрүүллээ. Биологийн идэвхийн үр дүнд үндэслэн протеолитик болон антиоксидант идэвхтэй сүүн хүчлийн бактерийн 4 өсгөврийг 16S рРНХ генийн дарааллыг харьцуулах аргаар тодорхойлоход D3-1 өсгөвөр Lactobacillus plantarum (98.76%), D13-1 өсгөвөр Lactobacillus fermentum (99.42%), A19-7 өсгөвөр Streptococcus thermophilus (99.90%), A19-9 өсгөвөр Lactobacillus kefiri (98.04%) зүйлд хамаарагдаж байгааг тогтоов. Эдгээр өсгөврүүд хүний хоол боловсруулах системийн ходоодны хүчил, цөстэй орчныг 3-8 цаг тэсвэрлэдэг пробиотик шинж чанартай учраас цаашид нарийвчлан судалж, функциональ хүнсний хөрөнгө болгон ашиглах, биологийн идэвхт бүтээгдэхүүн гарган авах технологи хөгжүүлэлтийн судалгаанд ашиглах боломжтой хэмээн дүгнэж байна. Түлхүүр үг: Протеолитик идэвх, пробиотик идэвх, биологийн идэвхт пептид
... Lovabyta et al. (2020) reported that L. bulgaricus reached 1.35 x 10 9 CFU/mL in edamame milk after 24 hours of fermentation. The high survival rate of LAB in soy milk is maintained by the presence of proteolytic activity which is released during its growth to break down protein into some amino acids to support its growth (Hou et al. 2015). ...
Anggraeni SL, Jayus J, Ratnadewi AAI, Nurhayati N. 2022. Edamame protein hydrolysis using Lactococcus lactis, Lactobacillus bulgaricus and Lactobacillus paracasei produce short peptides with higher antioxidant potential. Biodiversitas 23: 3604-3613. The high demand for protein sources for functional vegetable foods, especially proteins that have ACE (Angiotensin-Converting Enzyme) inhibitory activity has encouraged efforts to meet this need through exploration of potential protein sources and the development of food processing technology to modify the protein into derivative compounds in the form of short peptides to promote higher bioactivity than the native protein. This research focused on the hydrolysis of edamame proteins into shorter peptides through a fermentation process using a group of Lactic Acid Bacteria (LABs), that is Lactococcus lactis, Lactobacillus bulgaricus and L. paracasei, to gain a higher functional activity of its protein hydrolysate. Edamame milk was fermented with that LABs as starter culture until 24 hours at 37ºC. The activity of the protease released by the LABs was confirmed using the agar diffusion method based on the emergence of a clear zone surrounding the culture, while the antioxidant activity was confirmed with the ABTS and hydroxyl radical scavenging methods. The results exhibited that the population density of starter culture in edamame milk reached 108 CFU/mL, and the pH decreased from 6.75 to 4.15. All LABs used in fermentation were able to hydrolyze protein as indicated by the increasing degree of hydrolysis and changes in protein profile of SDS-PAGE analysis. In addition, when compared to the unfermented edamame milk, the protein hydrolysate from LABs fermentation showed an increase of ABTS and hydroxyl radical inhibitory activity, in which the highest IC50 values ??of 8.96 and 13.33 g/mL of each were found in edamame milk fermented by Lc. lactis InaCC B187. An increase in ACE inhibitory activity was also observed in edamame milk fermented using this microbe (9.80 g/µL). These findings indicate that Lc. lactis InaCC B187, L. delbrueckii subspecies bulgaricus FNCC41, and L. paracasei InaCC B145 have the potency as an effective starter culture to increase bioactive peptides in edamame soybeans potential for functional food sources.
... The highest total amino acid concentration in the sample ( Figure 5A) might be attributed to the strain hydrolyzed proteins forming the necessary amino acids required for growth (Hou et al., 2015). Amino acids play a key role in enhancing the flavor and increasing the nutrition of the sausages. ...
This study investigated the positive effects of complete replacement of nitrite with a Lactobacillus fermentum on the quality and safety of Chinese fermented sausages, and evaluated the risk of this strain. The effects of the strain on pH, color, nitrite, thiobarbituric acid reactive substances (TBARS), total volatile basenitrogen (TVB-N), metmyoglobin (Met-Mb), biological amines, free amino acid content, and sensory index have been studied. The results revealed that the strain reduced the pH of the sausages, which reduced the risk of food-borne pathogens, and accelerated the acidification and gelation process. The inoculation of the strain produced pink color similar to 50 mg/kg nitrite, significantly reducing the residual risk of nitrite in the sausages. In addition, the strain effectively improved quality and nutrition of the sausages through preventing fat oxidation, protein decomposition, and myoglobin oxidation and increasing free amino acid content. The harmful biogenic amines species of the treated sample were reduced, although the tyramine contents were higher than the control, and the contents of the two groups were all far below the specified limit (800 mg/kg). The sensory analysis showed that the strain enhanced the taste, flavor, sourness, and overall acceptability of the sample sausages. Therefore, replacing nitrite completely with the strain L. fermentum could be a potential strategy to produce healthier and safer acceptable sausages through decreasing the risk of nitrite and improving nutrition and quality of the sausages.
... The bioactive peptides (B.A.P.s) are produced by proteolytic microorganisms (mostly Bacillus) during food fermentation [50,51]. Peptides have some antihypertensive properties [52] and also play a vital functional role as antithrombic [53] and immunomodulatory agents [54]. Due to the lack of large-scale production facilities and soaring costs of the enzymes for protein hydrolysis, the production of B.A.P.s is still below the benchmark. ...
Fermentation processes in foods often lead to changes in nutritional and biochemical quality
relative to the starting ingredients. Fermented foods comprise very complex ecosystems consisting of
enzymes from raw ingredients that interact with the fermenting microorganisms’ metabolic activities.
Fermenting microorganisms provide a unique approach towards food stability via physical and
biochemical changes in fermented foods. These fermented foods can benefit consumers compared to
simple foods in terms of antioxidants, production of peptides, organoleptic and probiotic properties,
and antimicrobial activity. It also helps in the levels of anti-nutrients and toxins level. The quality and
quantity of microbial communities in fermented foods vary based on the manufacturing process and
storage conditions/durability. This review contributes to current research on biochemical changes
during the fermentation of foods. The focus will be on the changes in the biochemical compounds
that determine the characteristics of final fermented food products from original food resources.
... bulgaricus (L. delbrueckii) (Hou, Liu, Ren, Han, & Du, 2015) whereas 4 CEPs (PrtH1, PrtH2, PrtH3 and PrtH4) can be expressed, in a strain dependent manner, by Lactobacillus helveticus (L. helveticus) strains (Griffiths & Tellez, 2013). ...
... Each strain was tested with five different primer sets corresponding to different CEP genes. The primers described by Hou et al. (2015) were used for detection of prtB gene in L. delbrueckii strains. The primers used for the detection of prtH1 and prtH2 genes of L. helveticus were from Genay, Sadat, Gagnaire, and Lortal (2009) and the primers for prtH3 and prtH4 (same species) were from Broadbent et al. (2011). ...
... All L. delbrueckii strains were found to possess the prtB gene, which is so far the only CEP described for this species (Hou et al., 2015). L. helveticus strains showed more heterogeneity, being divided into two groups: 6 strains with prtH1 gene, and 3 strains with the combination prtH2/prtH3. ...
... They include PrtB from Lb. delbrueckii subsp. bulgaricus (Hou et al., 2015), PrtP from Lb. casei and Lb. paracasei (Kojic et al., 1991;Ikram-ul-Haq and Mukhtar, 2006;Alcántara et al., 2016), PrtR from Lb. rhamnosus and Lb. ...
The aim of this study was to investigate the probiotic properties of 174 Lactobacillus strains isolated from
Mongolian dairy products, and particularly their impact on intestinal calcium uptake and absorption. All isolates
underwent a first screening based on cell surface hydrophobicity, acid tolerance, tolerance to gastro-intestinal
digestion, autoaggregation, adhesion and cytotoxicity against intestinal cells. Six Lactobacillus strains from different
species (L. casei, L. kefiranofaciens, L. plantarum, L. fermentum, L. helveticus and L. delbrueckii) were selected,
and their impact on intestinal calcium uptake and transport was investigated using Caco-2. Five strains were able
to improve total calcium transport after 24 h contact with a differentiated Caco-2 cell monolayer. Concomitantly
the L. plantarum strain was able to increase cellular calcium uptake in Caco-2 cells by 10% in comparison to
control conditions. To determine which pathway(s) of calcium absorption was modulated by the strains, a qPCRbased
study on 4 genes related to calcium/vitamin D metabolism or tight junction integrity was conducted on
mucus-secreting intestinal HT-29 MTX cells. The L. plantarum strain modulates the transcellular pathway by
regulating the expression of vitamin D receptor (1.79 fold of control) and calcium transporter (4.77 fold of
control) while the L. delbrueckii strain acts on the paracellular pathway by modulating claudin-2 expression (2.83
fold of control). This work highlights the impact of Lactobacillus probiotic strains on intestinal calcium absorption
and for the first time give some evidence about the cellular pathways involved.
... They include PrtB from Lb. delbrueckii subsp. bulgaricus (Hou et al., 2015), PrtP from Lb. casei and Lb. paracasei (Kojic et al., 1991;Ikram-ul-Haq and Mukhtar, 2006;Alcántara et al., 2016), PrtR from Lb. rhamnosus and Lb. ...
To compensate for their amino acid auxotrophy, lactobacilli have developed the ability to hydrolyze proteins present in their environment. This proteolytic activity not only generates the free amino acids needed by the bacteria, but also a large variety of peptides, some of which are endowed with biological activities. These so-called "bioactive peptides" (BAPs) are interesting from a nutrition and healthcare perspective. The use of lactic acid bacteria (LAB) such as lactobacilli is an effective strategy for production and valorization of new BAPs. The proteolytic activity of lactobacilli is exerted in a strain-and species-dependent manner: each species exhibits different proteinase content, leading to a large variety of proteolytic activities. This underlines the high potential of Lactobacillus strains to produce novel hydrolysates and BAPs of major interest. This review aims at discussing the potential of different Lactobacillus species to release BAPs from fermentation media and processes. Strategies used for peptide production are presented. Additionally, we propose a methodology to select the most promising Lactobacillus strains as sources of BAPs. This methodology combines conventional approaches and in silico analyses.
