scholarly journals Characteristics of the Proteolytic Enzymes Produced by Lactic Acid Bacteria

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1858
Author(s):  
Marek Kieliszek ◽  
Katarzyna Pobiega ◽  
Kamil Piwowarek ◽  
Anna M. Kot
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Food Industry ◽  
Proteolytic Enzymes ◽  
Rapid Development ◽  
Peptide Transport ◽  
Wall Structure ◽  
Main Function ◽  
Bacterial Cells ◽  
Covalent Bonds

Over the past several decades, we have observed a very rapid development in the biotechnological use of lactic acid bacteria (LAB) in various branches of the food industry. All such areas of activity of these bacteria are very important and promise enormous economic and industrial successes. LAB are a numerous group of microorganisms that have the ability to ferment sugars into lactic acid and to produce proteolytic enzymes. LAB proteolytic enzymes play an important role in supplying cells with the nitrogen compounds necessary for their growth. Their nutritional requirements in this regard are very high. Lactic acid bacteria require many free amino acids to grow. The available amount of such compounds in the natural environment is usually small, hence the main function of these enzymes is the hydrolysis of proteins to components absorbed by bacterial cells. Enzymes are synthesized inside bacterial cells and are mostly secreted outside the cell. This type of proteinase remains linked to the cell wall structure by covalent bonds. Thanks to advances in enzymology, it is possible to obtain and design new enzymes and their preparations that can be widely used in various biotechnological processes. This article characterizes the proteolytic activity, describes LAB nitrogen metabolism and details the characteristics of the peptide transport system. Potential applications of proteolytic enzymes in many industries are also presented, including the food industry.

Encapsulation of Lactic Acid Bacteria in Sugar Matrices To Be Used as Starters in the Food Industry

2021 ◽  
pp. 55-61
Author(s):  
Natalia S. Brizuela ◽  
Liliana C. Semorile ◽  
Bárbara M. Bravo-Ferrada ◽  
Emma Elizabeth Tymczyszyn
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Food Industry

scholarly journals  Bacteriocin-producing lactic acid bacteria as a probiotic potential from Thai indigenous chickens

2012 ◽  
Vol 57 (No. 3) ◽  
pp. 137-149 ◽  
Author(s):  
H. Musikasang ◽  
N. Sohsomboon ◽  
A. Tani ◽  
S. Maneerat
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Inhibitory Activity ◽  
Proteolytic Enzymes ◽  
Penicillin G ◽  
Probiotic Properties ◽  
Indigenous Chickens ◽  
Probiotic Potential ◽  
Gastrointestinal Conditions ◽  
Acti Vity

Bacteriocin-producing lactic acid bacteria (LAB) were isolated and screened from the gastrointestinal tract (GIT) of Thai indigenous chickens. The bacteriocinogenic activities and the primary probiotic properties were determined. The bacteriocins produced by 14 strains of selected LAB displayed inhibitory activity against indicator strains after the supernatants were neutralized with NaOH in the following species: Lactobacillus sakei subsp. sakei JCM1157, Enterococcus faecalis VanB, Bacillus sp., and Listeria monocytogenes. The antagonistic acti-vity of selected LAB was inactivated or decreased after being treated with proteolytic enzymes (α-chymotrypsin and trypsin). CR5-1 strain exhibited the highest level of activity (5120 AU/ml) in the stationary phase against L. sakei subsp. sakei JCM1157 in MRS broth at 37°C. The nine isolates of selected LAB were investigated for primary probiotic properties. The survival of the nine isolates was found to decrease approximately by 3 log CFU/ml after passing through the gastrointestinal conditions. All isolates exhibited protein digestion on agar plates but no isolates showed the ability to digest starch and lipid. Most of them showed high susceptibilities to some antibiotics (penicillin G, tetracycline and erythromycin). Thirteen LAB strains producing bacteriocin with strongly inhibitory activity were identified as Lactobacillus salivarius and only one strain was identified by 16S rDNA sequence analysis as Lactobacillus agilis.    

Microbial development in distillers wet grains produced during fuel ethanol production from corn (Zea mays)

2007 ◽  
Vol 53 (9) ◽  
pp. 1046-1052 ◽  
Author(s):  
R. Michael Lehman ◽  
Kurt A. Rosentrater
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Heterotrophic Bacteria ◽  
Micrococcus Luteus ◽  
Phospholipid Fatty Acid ◽  
Dry Mass ◽  
Fuel Ethanol ◽  
Fatty Acid Analysis ◽  
Yeast Cells ◽  
Bacterial Cells

Distillers grains are coproduced with ethanol and carbon dioxide during the production of fuel ethanol from the dry milling and fermentation of corn grain, yet there is little basic microbiological information on these materials. We undertook a replicated field study of the microbiology of distillers wet grains (DWG) over a 9 day period following their production at an industrial fuel ethanol plant. Freshly produced DWG had a pH of about 4.4, a moisture content of about 53.5% (wet mass basis), and 4 × 105 total yeast cells/g dry mass, of which about 0.1% were viable. Total bacterial cells were initially below detection limits (ca. 106 cells/g dry mass) and then were estimated to be ∼5 × 107 cells/g dry mass during the first 4 days following production. Culturable aerobic heterotrophic organisms (fungi plus bacteria) ranged between 104 and 105 CFU/g dry mass during the initial 4 day period, and lactic acid bacteria increased from 36 to 103 CFU/g dry mass over this same period. At 9 days, total viable bacteria and yeasts and (or) molds topped 108 CFU/g dry mass and lactic acid bacteria approached 106 CFU/g dry mass. Community phospholipid fatty acid analysis indicated a stable microbial community over the first 4 days of storage. Thirteen morphologically distinct isolates were recovered, of which 10 were yeasts and molds from 6 different genera, 2 were strains of the lactic-acid-producing Pediococcus pentosaceus and only one was an aerobic heterotrophic bacteria, Micrococcus luteus . The microbiology of DWG is fundamental to the assessment of spoilage, deleterious effects (e.g., toxins), or beneficial effects (e.g., probiotics) in its use as feed or in alternative applications.

Investigation of Lactobacilli Properties

2014 ◽  
Vol 1040 ◽  
pp. 319-322
Author(s):  
E.V. Bulycheva ◽  
E.I. Korotkova ◽  
O.A. Voronova
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Bacterial Cells ◽  
Luminescence Method

In this paper for investigation of the medicine «Lactobacterin» containing lactic acid bacteria was used luminescence method. It is shown, that spectrum of the Lactobacilli has 3 peaks from different substances. It is shown that during 2 hours the bacterial cells are alive.

The Sourdough Microflora. Cellular Localization and Characterization of Proteolytic Enzymes in Lactic Acid Bacteria

LWT ◽  
1996 ◽  
Vol 29 (5-6) ◽  
pp. 561-569 ◽  
Author(s):  
Marco Gobbetti ◽  
Emanuele Smacchi ◽  
Patrick Fox ◽  
Leszek Stepaniak ◽  
Aldo Corsetti
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Cellular Localization ◽  
Proteolytic Enzymes

scholarly journals Automatic Segmentation and Classification of SEM Images of Bacteria Cells

2019 ◽  
Vol 8 (4) ◽  
pp. 12858-12860
Keyword(s):  
Image Analysis ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Automatic Segmentation ◽  
Morphological Characteristics ◽  
Bacterial Cells ◽  
Electron Microscopic ◽  
Sem Images ◽  
Edge Based ◽  
Watershed Method

In the field of microbiology, digital image analysis methods are receiving significant attention to automatically interpret images of bacterial cells. An automatic procedure to extract and classify images of lactic acid bacteria (LAB) is presented in this paper. Edge based watershed method with automatically generated markers were used to retain the image information at fine scales. The experiment was conducted on images containing one type of bacteria. The scanning electron microscopic (SEM) images of lactic acid bacteria (LAB) are used in this experiment. The image analysis and classification technique described in this paper is quick and simple to recognize organisms based on their morphological characteristics. The classification results indicate that routine methods for the detection, enumeration and identification of bacteria can be automated with use of direct microscopic methods

scholarly journals Bacteriocinogenic lactic acid bacteria in the traditional cereal-based beverage Boza: a genomic and functional approach

2021 ◽  
Author(s):  
Luciano Lopes Queiroz ◽  
Christian Hoffmann ◽  
Gustavo Augusto Lacorte ◽  
Bernadette Dora Gombossy de Melo Franco ◽  
Svetoslav Dimitrov Todorov
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Proteolytic Enzymes ◽  
Food Product ◽  
Balkan Peninsula ◽  
Microbial Interactions ◽  
Fermented Foods ◽  
Pediococcus Pentosaceus ◽  
Bacteriophage Infection ◽  
A Cell

Boza is a traditional low-alcohol fermented beverage from the Balkan Peninsula, frequently explored as a functional food product. The product is rich in Lactic Acid Bacteria (LAB) and some of them can produce bacteriocins. In this study, a sample of Boza from Belogratchik, Bulgaria, was analyzed for the presence of bacteriocinogenic LAB, and after analyses by RAPD-PCR, three representative isolates were characterized by genomic analyses, using whole genome sequencing. Isolates identified as Pediococcus pentosaceus ST75BZ and Pediococcus pentosaceus ST87BZ contained operons encoding for bacteriocins pediocin PA-1 and penocin A, while isolate identified as P. acidilactici ST31BZ contained only the operon for pediocin PA-1 and a CRISPR/Cas system for protection against bacteriophage infection. The antimicrobial activity of bacteriocins produced by the three isolates was inhibited by treatment of the cell-free supernatants with proteolytic enzymes. The produced bacteriocins inhibited the growth of Listeria monocytogenes, Enterococcus spp. and some Lactobacillus spp., among other tested species. The levels of bacteriocin production varied from 3200 AU/ml to 12800 AU/ml recorded against L. monocytogenes 104, 637 and 711, measured at 24 h of incubation at 37oC. All bacteriocins remained active after incubation at pH 2.0 to 10.0. The activity mode of the studied bacteriocins was bactericidal, as determined against L. monocytogenes 104, 637 and 711. In addition, bactericidal activity was demonstrated using a cell leakage β-galactosidase assay, indicating a pore formation mechanism as a mode of action. The present study highlights the importance of combining metagenomic analyses and traditional microbiological approaches as way of characterizing microbial interactions in fermented foods.

Sign in / Sign up

Export Citation Format

Share Document