Understanding the cryotolerance of lactic acid bacteria using combined synchrotron infrared and fluorescence microscopies

The Analyst ◽  
2015 ◽  
Vol 140 (17) ◽  
pp. 5920-5928 ◽  
Author(s):  
Stéphanie Passot ◽  
Julie Gautier ◽  
Frédéric Jamme ◽  
Stéphanie Cenard ◽  
Paul Dumas ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Fluorescence Microscopy ◽  
Physiological State ◽  
Bacterial Cells ◽  
Ftir Microspectroscopy ◽  
Simultaneous Assessment

Combining synchrotron-FTIR microspectroscopy and fluorescence microscopy made it possible the simultaneous assessment of biochemistry and physiological state of small bacterial cells for better understanding the mechanisms of cell cryotolerance.

Insights into lactic acid bacteria cryoresistance using FTIR microspectroscopy

2021 ◽  
Author(s):  
Amélie Girardeau ◽  
Stéphanie Passot ◽  
Julie Meneghel ◽  
Stéphanie Cenard ◽  
Pascale Lieben ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Ftir Microspectroscopy

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.

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

IDENTIFIKASI MOLEKULAR BAKTERI ASAM LAKTAT Lactobacillus paracasei YANG ADA PADA LAPISAN MINYAK VCO

2017 ◽  
Vol 2 (2) ◽  
pp. 79
Author(s):  
Suryani Suryani ◽  
Dedi Nofiandi ◽  
Husni Mukhtar ◽  
Melona Siska ◽  
Abdi Dharma ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Antiviral Agents ◽  
Coconut Oil ◽  
Pathogenic Fungi ◽  
Coconut Milk ◽  
Lactobacillus Paracasei ◽  
Bacterial Cells ◽  
Virgin Coconut Oil ◽  
Biochemical Tests

<p><em>Virgin Coconut Oil is an oil of coconut milk fermentation that has many uses such as can prevent HIV, because it functions as antibacterial, antifungal and antiviral. Antibacterial, antifungal and antiviral agents are found in bacteria lactic acid bacteriocin, a peptide that can destroy bacterial cells and pathogenic fungi and viral cells. The aim of this study was to identify molecularly lactic acid bacteria isolated and morphologically identified and biochemical tests, from fermented coconut milk. Apparently lactic acid bacteria is Lactobacillus paracasei strain 1.7.</em></p><p> </p><p>Virgin Coconut Oil adalah minyak dari fermentasi santan kelapa yang mempunyai banyak sekali kegunaan diantaranya  dapat mencegah HIV, karena berfungsi sebagai antibakteri, antijamur dan antivirus. Zat antibakteri, antijamur dan antivirus itu terdapat pada bakteri asam laktat yaitu bakteriosin, berupa peptida yang dapat menghancurkan sel bakteri dan jamur patogen serta sel virus. Tujuan penelitian ini adalah mengidentifikasi secara molekular bakteri asam laktat  yang telah diisolasi dan diidentifikasi secara morfologi dan uji – uji biokimia, dari santan yang difermentasi.  Ternyata bakteri asam laktat nya adalah Laktobacillus paracasei strain 1.7.</p><p> </p>

scholarly journals Biofilm formation of Candida Spp. isolated from the vagina and antibiofilm activities of lactic acid bacteria on the these Candida Isolates

2020 ◽  
Vol 20 (2) ◽  
pp. 641-648
Author(s):  
Merih Kıvanç ◽  
Sevda Er
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Virulence Factors ◽  
Lactobacillus Acidophilus ◽  
Biofilm Formation ◽  
Bacterial Cells ◽  
Candida Spp ◽  
Plate Method ◽  
Microtitration Plate ◽  
Esterase Activities

Background: In this study, it was aimed to investigate the effects of bacterial cells and cell-free filtrates of Lactobacillus acidophilus 8MR7 and Lactobacillus paracasei subspecies paracasei 10MR8 on the biofilm formation of 3 Candida tropicalis, 3 C. glabrata and 12 C. albicans isolated from the vagina and identified their virulence factors. Methods: Haemolytic activities esterase activities, and phospholipase activities as virulence factors of Candida strains were determined. Biofilm formations of these isolates were determined by Congo Red agar and microtitration plate method. Anti-biofilm activities of bacterial cells and cell-free filtrates of L. acidophilus 8MR7 and L. paracasei subspecies paracasei 10MR8 on Candida isolates were determined by the microtitration plate method. Results: Bacterial cells of L. acidophilus 8MR7 and L. paracasei subspecies paracasei 10MR8 were not very effective in the in- hibition of biofilm, whereas it has been observed that the cell-free filtrates of these bacteria inhibit the formation of biofilms of Candida strains. Although the main mechanism for inhibiting the formation of Candida spp. biofilm is the competition for adhesion, it is concluded that the substances contained in the cell-free filtrates of lactic acid bacteria are also important. Conclusion: These isolates promise hope as potential bacteria that can be used for anti-adhesion purposes in health-care materials. Keywords: Lactobacillus acidophilus; L. paracesei subspecies paracesei; vagina; biofilm.

scholarly journals An alternative method for screening lactic acid bacteria for the production of exopolysaccharides with rapid confirmation

2012 ◽  
Vol 32 (4) ◽  
pp. 710-714 ◽  
Author(s):  
Elinalva Maciel Paulo ◽  
Murilo Pinho Vasconcelos ◽  
Ivelise Santiago Oliveira ◽  
Helen Michelle de Jesus Affe ◽  
Rosely Nascimento ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Filter Paper ◽  
Solid Medium ◽  
Culture Conditions ◽  
Bacterial Cells ◽  
Absolute Alcohol ◽  
Alternative Method ◽  
Excess Substrate ◽  
Nitrogen Phosphorus

The accumulation of exopolysaccharides (EPS) produced by microorganisms occurs in the presence of excess substrate and limiting conditions of elements that are essential to growth, such as nitrogen, phosphorus, sulfur, and magnesium. The presence of EPS produced by bacterial cells contributes to slime colonies formation in solid medium and increased viscosity in liquid medium. This paper proposes an alternative method for screening EPS-producing lactic acid bacteria using solid medium-containing discs of filter paper that are saturated with active cultures. The screening was carried out under different culture conditions varying the type of sugar, pH, and temperature. EPS production was visualized by the presence of mucoid colonies on the discs, which was confirmed by the formation of a precipitate when part of this colony was mixed with absolute alcohol. The established conditions for obtaining a high number of isolates producing EPS were 10% sucrose, pH 7.5 and 28 ºC. This method proved to be effective and economical because several strains could be tested on the same plate, with immediate confirmation.

Binding of heterocyclic amines by lactic acid bacteria from miso, a fermented Japanese food

1998 ◽  
Vol 44 (2) ◽  
pp. 109-115 ◽  
Author(s):  
Rajam Rajendran ◽  
Yoshiyuki Ohta
Keyword(s):  
Cell Wall ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Binding Activity ◽  
Fermented Food ◽  
Heterocyclic Amines ◽  
Wall Material ◽  
Bromocresol Purple ◽  
Bacterial Cells ◽  
The Impact

Miso, a widely used Japanese fermented food was analysed for its lactic acid bacterial count on bromocresol purple agar. The binding of eight different foodborne carcinogenic heterocyclic amines to 25 bacterial isolates from miso were investigated. The heterocyclic amines used were 3-amino-1,4-dimethyl[5H]pyrido(4,3-b)indole (Trp-P-1), 3-amino-1-methyl[5H]pyrido(4,3-b)indole (Trp-P-2), 2-amino-6-methyldipyrido(1,2-a:3'2'-d)imidazole (Glu-P-1), 2-amino-1-methyl-6-phenylimidazo(4,5-b)pyridine (PhIP), 2-amino-dimethylimidazo(4,5f)quinoline (IQ), 2-amino-3,4-dimethylimidazo(4,5-f) quinoline (MeIQ), 2-amino-3,8-dimethylimidazo(4,5-f)quinoxaline (MeIQx), and 2-amino-3-methyl-9H-pyrido(2,3)indole (MeAαC). The lyophilized cells of all of the isolates exhibited high binding activity towards Trp-P-1, Trp-P-2, MeAαC, and PhIP, while Glu-P-1 and IQ were not effectively bound. Of the isolates tested, the strongest and weakest binders were identified as Pediococcus acidilactici 1 and 2, respectively. Lyophilized cell wall fractions, heat-treated cells, and the cytoplasmic contents of P. acidilactici 1 and 2 were analysed for their ability to bind to different mutagens. Pure cell wall and peptidoglycan showed greater binding activity than the bacterial cells. Cytoplasmic content also showed some binding, but it was much less effective. The impact of enzymes (amylase, protease, cellulase, chitinase, muraminase, and peptidase) and acetylation of Trp-P-1 and IQ on the binding action of bacteria and cell wall material were also analysed to understand the possible processes involved in the binding of lactic acid bacteria to carcinogenic heterocyclic amines.Key words: mutagen, heterocyclic amines, lactic acid bacteria, binding, miso.

scholarly journals Biosurfactants Production Ability of Lactic Acid Bacteria Strains, Emulsification Activity and Cell Adhesion to Hydrocarbons

2020 ◽  
Vol 70 (12) ◽  
pp. 4493-4498
Keyword(s):  
Lactic Acid ◽  
Cell Adhesion ◽  
Lactic Acid Bacteria ◽  
Engine Oil ◽  
Bacterial Cells ◽  
Ionic Charge ◽  
Polluted Soils ◽  
Emulsification Activity ◽  
Emulsification Index ◽  
Hydrocarbon Degraders

The paper presents the results of research carried out for screening of 10 lactic acid bacteria strains with antifungal activity for their ability to produce biosurfactants and to select the most performant strains for further biotechnological application as hydrocarbon-degraders in bioremediation of oil-polluted soils. All the strains of lactic acid bacteria were able to form circle displacement area in engine oil 2T with various diameters, confirming the production of biosurfactants in various amounts. Emulsification activity was registered, with values of emulsification index E24 ranging from minimum 25.75% for the strain LAB 132 to maximum 75.93% for the strain LAB 13. Bacterial cells presented adhesion to hydrocarbons (kerosene), degrees of hydrophobicity variable, ranged between 25,57% for LAB 58 and 75,42% for Lpl and formed emulsions stable for over 7 days. Results of the assay of ionic charge revealed the anionic nature of the biosurfactants. Keywords: biosurfactants, lactic acid bacteria, emulsification, hydrophobicity, cell adhesion to hydrocarbons

Etude de la nisinase produite parStreptococcus thermophilus

1962 ◽  
Vol 29 (3) ◽  
pp. 233-240 ◽  
Author(s):  
Par R. Alifax ◽  
R. Chevalier
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Streptococcus Thermophilus ◽  
Bacterial Cells ◽  
Optimum Ph

SummaryOf several strains of lactic acid bacteria which produced nisinase,Streptococcus thermophilus, strain TJ, was the most active. The optimum pH for extraction of the nisinase from an acetone preparation of bacterial cells and for incubation of the solution containing nisin and nisinase was in the neighbourhood of 7·0. The proportions of nisin destroyed by the nisinase under various conditions were determined. Also, it has been shown that nisinase has no action on a number of antibiotics, including subtilin.

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