scholarly journals Polysaccharide Hydrogels for the Protection of Dairy-Related Microorganisms in Adverse Environmental Conditions

Molecules ◽  
2021 ◽  
Vol 26 (24) ◽  
pp. 7484
Author(s):  
Ilja Gasan Osojnik Črnivec ◽  
Tigran Neresyan ◽  
Yuliana Gatina ◽  
Vid Kolmanič Bučar ◽  
Mihaela Skrt ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Environmental Conditions ◽  
Growth Media ◽  
Double Product ◽  
Term Survival ◽  
Mixed Culture Fermentation ◽  
Growth Environment ◽  
Hydrogel Matrix ◽  
Adverse Environmental Conditions

Adverse environmental conditions are severely limiting the use of microorganisms in food systems, such as probiotic delivery, where low pH causes a rapid decrease in the survival of ingested bacteria, and mixed-culture fermentation, where stepwise changes and/or metabolites of individual microbial groups can hinder overall growth and production. In our study, model probiotic lactic acid bacteria (L. plantarum ATCC 8014, L. rhamnosus GG) and yeasts native to dairy mixed cultures (Kluyveromyces marxianus ZIM 1868) were entrapped in an optimized (cell, alginate and hardening solution concentration, electrostatic working parameters) Ca-alginate system. Encapsulated cultures were examined for short-term survival in the absence of nutrients (lactic acid bacteria) and long-term performance in acidified conditions (yeasts). In particular, the use of encapsulated yeasts in these conditions has not been previously examined. Electrostatic manufacturing allowed for the preparation of well-defined alginate microbeads (180–260 µm diameter), high cell-entrapment (95%) and viability (90%), and uniform distribution of the encapsulated cells throughout the hydrogel matrix. The entrapped L. plantarum maintained improved viabilities during 180 min at pH 2.0 (19% higher when compared to the free culture), whereas, L. rhamnosus appeared to be less robust. The encapsulated K. marxianus exhibited double product yields in lactose- and lactic acid-modified MRS growth media (compared to an unfavorable growth environment for freely suspended cells). Even within a conventional encapsulation system, the pH responsive features of alginate provided superior protection and production of encapsulated yeasts, allowing several applications in lacto-fermented or acidified growth environments, further options for process optimization, and novel carrier design strategies based on inhibitor charge expulsion.

scholarly journals ANALISIS VIABILITAS LACTOBACILLUS LACTIS PADA INOVASI MEDIA DASAR PERTUMBUHAN ALTERNATIF DAN MEDIA DASAR PENEPUNGAN BAKTERI ASAM LAKTAT

2020 ◽  
Vol 4 (2) ◽  
pp. 16-22
Author(s):  
Ani Sulastri ◽  
Baso Manguntungi
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Shelf Life ◽  
Bacterial Growth ◽  
Alternative Media ◽  
Plate Count ◽  
Growth Media ◽  
Media Formulation ◽  
The Media ◽  
Lactobacillus Lactis

The limited shelf life in a food requires a natural preservative so that the food used is not easily damaged and has a longer shelf life, namely by using lactic acid bacteria (BAL) using alternative media. By using lactic acid bacteria, the time in the storage period food products can be extended. The purpose of this study was to determine the viability of the Lactobacillus lactis bacteria on an alternative growth base media and a media on the media of bacteria. Lactic acid bacteria were rejuvenated and culture propagation of 5 ?l was inoculated into 5 mL of MRSB media. Formulation media used for bacterial growth such as whey tofu + 5% sucrose + 1% urea. The alternative media was incubated for 24 hours. Bacterial growth was observed at 0, 4, 8 and 16 hours using the TPC (Total Plate count) method. Various media Lactobacillus lactis bacterial deposition was grown on MRSB media and dried with freeze dry for 48 hours and the viability of Lactobacillus lactis was tested. The basic growth media that can be used are Lactobacillus lactis bacteria, namely whey tofu + sucrose 5% + urea 1% as well as Lactobacillus lactis viability results in various media which are grown on MRS media and various alternative media shows that the media has a 100% carrageenan composition able to maintain the viability of Lactobacillus lactis cells.

INVESTIGATION OF VARIOUS WAYS TO STABILIZE LACTIC ACID BACTERIA CELLS DURING LONG-TERM STORAGE

2020 ◽  
pp. 388-389
Author(s):  
Yu. Nikolaev ◽  
R. Ulanova ◽  
I. Shakir ◽  
A. Khreptugova
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Lactic Acid Bacterium ◽  
Enterococcus Faecium ◽  
Term Survival ◽  
Long Term Survival ◽  
Long Term Storage ◽  
Term Storage

Various methods of stabilizing the cells of the lactic acid bacterium Enterococcus faecium during long-term storage were studied. It is shown that the long-term survival of E. faecium is promoted by the addition of Enterosgel, Polysorb, the use of LB substratum, as well as their immobilization in humic-silanol gel.

Rapid procedure for acid adaptation of oral lactic-acid bacteria and further characterization of the response

1997 ◽  
Vol 43 (2) ◽  
pp. 143-148 ◽  
Author(s):  
Yousheng Ma ◽  
Timothy M. Curran ◽  
Robert E. Marquis
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Streptococcus Mutans ◽  
Acid Tolerance ◽  
Growth Media ◽  
Oral Microbiota ◽  
Adaptive Responses ◽  
Acid Adaptation ◽  
General Importance ◽  
Time Required

Acid-adaptive responses could be induced readily in oral lactic-acid bacteria by growing them in batch cultures with excess sugar or more conveniently and rapidly by transferring cells to acidified growth media for the time required for biomass doubling. The response of Streptococcus mutans GS-5 was induced in a progressive rather than all-or-nothing way, and the extent of acid tolerance was inversely related to the pH of the inducing medium over a range from 8.5 to 5. The weak acids fluoride, acetate, or lactate did not measurably enhance acid adaptation, and so the response did not appear to depend primarily on changes in ΔpH or the proton motive force across the cell membrane. Transcription and translation to form new proteins did appear to be necessary, as indicated by inhibition of adaptation by rifampin or chloramphenicol and by lack of adaptation by cells suspended in phosphate buffer at pH 5. Streptococcus salivarius and Lactobacillus casei were acid adapted by the rapid method, and the method appeared to be generally useful for oral lactic-acid bacteria. The rapid induction of the response in multiple oral lactic-acid bacteria suggests that it is of general importance for maintaining a diversity of organisms in the oral microbiota, which is regularly subjected to acid stresses.Key words: acid adaptation, oral lactic-acid bacteria, Streptococcus mutans.

scholarly journals Novel Approach to Mycotoxin Detoxification in Farm Animals Using Probiotics Added to Feed Stuffs

2010 ◽  
Author(s):  
Roni Shapira ◽  
Judith Grizzle ◽  
Nachman Paster ◽  
Mark Pines ◽  
Chamindrani Mendis-Handagama
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
High Efficiency ◽  
Farm Animals ◽  
Probiotic Bacteria ◽  
Expression Vectors ◽  
Growth Media ◽  
Strong Promoter ◽  
E Coli ◽  
Major Interest

T-2 toxin, a toxic product belongs to the trichothecene mycotoxins, attracts major interest because of its severe detrimental effects on the health of human and farm animals. The occurrence of trichothecenes contamination is global and they are very resistant to physical or chemical detoxification techniques. Trichothecenes are absorbed in the small intestine into the blood stream. The hypothesis of this project was to develop a protecting system using probiotic bacteria that will express trichothecene 3-O-acetyltransferase (Tri101) that convert T-2 to a less toxic intermediate to reduce ingested levels in-situ. The major obstacle that we had faced during the project is the absence of stable and efficient expression vectors in probiotics. Most of the project period was invested to screen and isolate strong promoter to express high amounts of the detoxify enzyme on one hand and to stabilize the expression vector on the other hand. In order to estimate the detoxification capacity of the isolated promoters we had developed two very sensitive bioassays.The first system was based on Saccharomyces cerevisiae cells expressing the green fluorescent protein (GFP). Human liver cells proliferation was used as the second bioassay system.Using both systems we were able to prove actual detoxification on living cells by probiotic bacteria expressing Tri101. The first step was the isolation of already discovered strong promoters from lactic acid bacteria, cloning them downstream the Tri101 gene and transformed vectors to E. coli, a lactic acid bacteria strain Lactococcuslactis MG1363, and a probiotic strain of Lactobacillus casei. All plasmid constructs transformed to L. casei were unstable. The promoter designated lacA found to be the most efficient in reducing T-2 from the growth media of E. coli and L. lactis. A prompter library was generated from L. casei in order to isolate authentic probiotic promoters. Seven promoters were isolated, cloned downstream Tri101, transformed to bacteria and their detoxification capability was compared. One of those prompters, designated P201 showed a relatively high efficiency in detoxification. Sequence analysis of the promoter region of P201 and another promoter, P41, revealed the consensus region recognized by the sigma factor. We further attempted to isolate an inducible, strong promoter by comparing the protein profiles of L. casei grown in the presence of 0.3% bile salt (mimicking intestine conditions). Six spots that were consistently overexpressed in the presence of bile salts were isolated and identified. Their promoter reigns are now under investigation and characterization.

scholarly journals Cloning and Heterologous Expression of Hematin-Dependent Catalase Produced by Lactobacillus plantarum CNRZ 1228

2004 ◽  
Vol 70 (1) ◽  
pp. 603-606 ◽  
Author(s):  
Hikmate Abriouel ◽  
Anette Herrmann ◽  
Joachim Stärke ◽  
Nuha M. K. Yousif ◽  
Agus Wijaya ◽  
...  
Keyword(s):  
Amino Acids ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Heterologous Expression ◽  
Lactobacillus Plantarum ◽  
Environmental Conditions ◽  
Catalase Activity ◽  
Heterologous Host ◽  
Pcr Screening ◽  
Catalase Gene

ABSTRACT Lactobacillus plantarum CNRZ 1228 exhibited heme-dependent catalase activity under environmental conditions similar to those encountered during sausage fermentation. The 1,455-bp catalase gene (katL) was cloned and encoded a protein of 484 amino acids. Expression of katL in a heterologous host showed that katL encodes a functional catalase. PCR screening of selected strains of lactic acid bacteria for katL indicated the presence of similar genes in other strains of lactobacilli.

scholarly journals Sorghum Malt Extract as a Growth Medium for Lactic Acid Bacteria Cultures: A Case of Lactobacillus plantarum MNC 21

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Stellah Byakika ◽  
Ivan Muzira Mukisa ◽  
Yusuf Byenkya Byaruhanga
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Lactobacillus Plantarum ◽  
Low Cost ◽  
Growth Media ◽  
Total Sugars ◽  
Microbial Counts ◽  
Cost Growth ◽  
Sorghum Malt ◽  
Mrs Broth

Cultivation of lactic acid bacteria cultures is vital for research and commercial production of fermented foods. However, the conventional growth media used are generally costly. Malt extracts from four sorghum varieties (SESO 1, SESO 3, Epuripur, and Eyera) were evaluated as alternative low-cost growth media for Lactobacillus plantarum MNC 21. Saccharified sorghum malt extracts were inoculated with 4 log cfu/mL MNC 21 and incubated at 30°C for 24 h. MRS broth was the reference medium. Microbial counts, pH, titratable acidity (TA), free amino nitrogen (FAN), and total sugars were measured. Maximum microbial counts in the extracts and MRS broth were 9 and 10 log cfu/mL, respectively. Maximum growth rate in the extracts was 0.7–0.9 log cfu/mL/h and 0.8 log cfu/mL/h in MRS broth. The final pH of the extracts was 3.5–3.6, with an overall increase in TA of 1.2% in Epuripur and 0.2% in other varieties. Final pH and TA of MRS broth were 4.1 and 1.3%, respectively. Total sugars dropped by 95.2% and FAN by 2.1% in MRS broth. In contrast, total sugars and FAN dropped by 5.6–9.1% and 24.9–32.7% respectively, in the extracts. Sorghum malt extracts can be adopted as alternative low-cost growth media for lactic acid bacteria cultures.

Characterization of kefir grains grown in cows' milk and in soya milk

1999 ◽  
Vol 66 (2) ◽  
pp. 327-333 ◽  
Author(s):  
ANALÍA G. ABRAHAM ◽  
GRACIELA L. DE ANTONI
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Complex Mixture ◽  
Lactobacillus Brevis ◽  
Dry Weight ◽  
Acetic Acid Bacteria ◽  
Growth Media ◽  
Yellow Colour ◽  
Soya Milk ◽  
Kefir Grains

Kefir is a refreshing fermented milk with a slightly acidic taste obtained by incubating milk with kefir grains (Saloff-Coste, 1996). Kefir grains are a complex mixture of lactic acid bacteria and yeasts in a strong and specific association. They are characterized by an irregular form, a folded and uneven surface and a white or slightly yellow colour. They are tough and resilient and have a characteristic acid taste (Bottazzi et al. 1994). The basic microflora contains lactococci, homofermentative and heterofermentative lactobacilli, yeasts and acetic acid bacteria (Bottazzi et al. 1994; Rea et al. 1996). Among the yeasts isolated from grains and identified are Candida kefir, Saccharomyces cerevisiae, Sac. delbrueckii, Cand. holmii, Sac. unisporus and Sac. lipolytica (Angulo et al. 1993; Marshall, 1993; Garrote et al. 1997). Lactobacillus brevis, Lb. viridescens, Lb. casei, Lb. kefir, Lb. kefiranofaciens, Lb. kefirgranum, Lb. parakefir, Leuconostoc spp. and Lactococcus lactis are among the lactic acid bacteria present in the grains (Marshall et al. 1984; Toba et al. 1991; Takizawa et al. 1994; Garrote et al. 1997). The mixed microflora of yeasts and bacteria is held together by a matrix containing (g/kg dry weight) protein 340, polysaccharide 470 (Ottogalli et al. 1973).The study of kefir grains in milk has been centred on the characteristics of the polysaccharide produced by lactobacilli within the grain (Yokoi et al. 1991). This polysaccharide, named kefiran, is composed of glucose and galactose (Yokoi et al. 1991). It has been suggested that proteins are incorporated from the growth media (Bassette & Acosta 1988), but no details about structure and composition are available.Soyabeans are an important component of the diet in many countries and have been used to obtain fermented products such as sogurt (Mann, 1991). Special attention has been given to the growth of, and sugar utilization by, Bifidobacterium spp., Lb. delbrueckii subsp. bulgaricus and Streptococcus thermophilus in soya milk (Buono et al. 1990; Murti et al. 1993; Ankenman Granata & Morr, 1996). To our knowledge, there have been no attempts to ferment soya milk with kefir grains.The aim of this study was to investigate the growth of kefir grains in soya milk and the composition of these grains, focusing on the matrix proteins.

Biological Detoxification of the Mycotoxin Deoxynivalenol (DON) to Improve Safety of Animal Feed and Food

2010 ◽  
Author(s):  
Ting Zhou ◽  
Roni Shapira ◽  
Peter Pauls ◽  
Nachman Paster ◽  
Mark Pines
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
High Efficiency ◽  
Fluorescent Protein ◽  
Animal Feed ◽  
Probiotic Bacteria ◽  
Expression Vectors ◽  
Growth Media ◽  
Strong Promoter ◽  
E Coli

The trichothecene deoxynivalenol (DON, vomitoxin), one of the most common mycotoxin contaminants of grains, is produced by members of the Fusarium genus. DON poses a health risk to consumers and impairs livestock performance because it causes feed refusal, nausea, vomiting, diarrhea, hemolytic effects and cellular injury. The occurrence of trichothecenes contamination is global and they are very resistant to physical or chemical detoxification techniques. Trichothecenes are absorbed in the small intestine into the blood stream. The overall objective of this project was to develop a protecting system using probiotic bacteria that will express trichothecene 3-O-acetyltransferase (Tri101) that convert T-2 to a less toxic intermediate to reduce ingested levels in-situ. The major obstacle that we had faced during the project is the absence of stable and efficient expression vectors in probiotics. Most of the project period was invested to screen and isolate strong promoter to express high amounts of the detoxify enzyme on one hand and to stabilize the expression vector on the other hand. In order to estimate the detoxification capacity of the isolated promoters we had developed two very sensitive bioassays.The first system was based on Saccharomyces cerevisiae cells expressing the green fluorescent protein (GFP). Human liver cells proliferation was used as the second bioassay system.Using both systems we were able to prove actual detoxification on living cells by probiotic bacteria expressing Tri101. The first step was the isolation of already discovered strong promoters from lactic acid bacteria, cloning them downstream the Tri101 gene and transformed vectors to E. coli, a lactic acid bacteria strain Lactococcuslactis MG1363, and a probiotic strain of Lactobacillus casei. All plasmid constructs transformed to L. casei were unstable. The promoter designated lacA found to be the most efficient in reducing T-2 from the growth media of E. coli and L. lactis. A prompter library was generated from L. casei in order to isolate authentic probiotic promoters. Seven promoters were isolated, cloned downstream Tri101, transformed to bacteria and their detoxification capability was compared. One of those prompters, designated P201 showed a relatively high efficiency in detoxification. Sequence analysis of the promoter region of P201 and another promoter, P41, revealed the consensus region recognized by the sigma factor. We further attempted to isolate an inducible, strong promoter by comparing the protein profiles of L. casei grown in the presence of 0.3% bile salt (mimicking intestine conditions). Six spots that were consistently overexpressed in the presence of bile salts were isolated and identified. Their promoter reigns are now under investigation and characterization.

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