scholarly journals Effect of Feeding Different Cultivars of Leucaena leucocephala on Rumen-Based in vitro Anaerobic Fermentations

Proceedings ◽  
2020 ◽  
Vol 36 (1) ◽  
pp. 96
Author(s):  
Diane Ouwerkerk ◽  
Anita Maguire ◽  
Jenny Gravel ◽  
Cathy Minchin ◽  
Michael Gravel ◽  
...  
Keyword(s):  
Leucaena Leucocephala ◽  
Negative Impact ◽  
Starter Culture ◽  
Starter Cultures ◽  
Beef Industry ◽  
Department Of Agriculture ◽  
Fermentation Time ◽  
Degrading Bacteria ◽  
Anaerobic Fermentations

The leguminous forage shrub, Leucaena leucocephala, is one of the few nutritional options available to significantly improve beef productivity in Northern Australia. A mixed bacterial rumen inoculum for the detoxification of mimosine (present in Leucaena) and its toxic derivatives 3,4 DHP and 2,3 DHP has been produced in an anaerobic fermenter for the last 23 years by the Queensland Department of Agriculture and Fisheries, using the commercial cultivar Cunninghamii. The development and release of a new psyllid-resistant cultivar ‘Redlands’, offers potential for increasing uptake by the beef industry but brings unanswered questions about its impact on the survival of the toxin degrading bacteria Synergistes jonesii and the overall efficacy of the current inoculum. A series of 30-day anaerobic fermentations were undertaken using the same starter cultures used in the production of commercial inoculum but fed daily with one of three Leucaena cultivars: Cunninghamii, Redlands or Wondergraze. Populations of S. jonesii were monitored daily using a quantitative PCR assay and the ability of the fermentation to detoxify mimosine and its derivatives were assayed on days 10, 15, 20, 25 and 30. Feeding the new Redlands cultivar had a negative impact on S. jonesii numbers and the ability to detoxify 3,4 DHP. However, as fermentation time increased, the S. jonesii populations adapted to the Redlands cultivar. A follow-on fermentation using a starter culture obtained from Day 30 of a Redlands fermentation, showed an immediate increase in S. jonesii populations and was able to detoxify mimosine and its toxic derivatives.

scholarly journals Yogurt Produced by Novel Natural Starter Cultures Improves Gut Epithelial Barrier In Vitro

2020 ◽  
Vol 8 (10) ◽  
pp. 1586 ◽  
Author(s):  
Nikola Popović ◽  
Emilija Brdarić ◽  
Jelena Đokić ◽  
Miroslav Dinić ◽  
Katarina Veljović ◽  
...  
Keyword(s):  
Dairy Product ◽  
Starter Culture ◽  
Streptococcus Thermophilus ◽  
Starter Cultures ◽  
Added Value ◽  
Lactobacillus Bulgaricus ◽  
Intestinal Epithelial ◽  
Beneficial Effects ◽  
Health Promoting

Yogurt is a traditional fermented dairy product, prepared with starter cultures containing Streptococcus thermophilus and Lactobacillus bulgaricus that has gained widespread consumer acceptance as a healthy food. It is widely accepted that yogurt cultures have been recognized as probiotics, due to their beneficial effects on human health. In this study, we have characterized technological and health-promoting properties of autochthonous strains S. thermophilus BGKMJ1-36 and L. bulgaricus BGVLJ1-21 isolated from artisanal sour milk and yogurt, respectively, in order to be used as functional yogurt starter cultures. Both BGKMJ1-36 and BGVLJ1-21 strains have the ability to form curd after five hours at 42 °C, hydrolyze αs1-, β-, and κ- casein, and to show antimicrobial activity toward Listeria monocytogenes. The strain BGKMJ1-36 produces exopolysaccharides important for rheological properties of the yogurt. The colonies of BGKMJ1-36 and BGVLJ1-21 strains that successfully survived transit of the yogurt through simulated gastrointestinal tract conditions have been tested for adhesion to intestinal epithelial Caco-2 cells. The results reveal that both strains adhere to Caco-2 cells and significantly upregulate the expression of autophagy-, tight junction proteins-, and anti-microbial peptides-related genes. Hence, both strains may be interesting for use as a novel functional starter culture for production of added-value yogurt with health-promoting properties.

scholarly journals Effect of the Addition of Milk Protein Preparations on Selected Quality Parameters and Nutritional Characteristics of Kefir

2021 ◽  
Vol 11 (3) ◽  
pp. 966
Author(s):  
Małgorzata Ziarno ◽  
Rozeta Hasalliu ◽  
Angelika Cwalina
Keyword(s):  
Milk Protein ◽  
Ph Value ◽  
Starter Culture ◽  
Milk Proteins ◽  
Quality Parameters ◽  
Starter Cultures ◽  
Total Protein Content ◽  
Protein Preparation ◽  
Available Lysine

The aim of this study was to evaluate the effect of the addition of various milk protein powder preparations (MPC-80, WPC-70, sweet whey, non-demineralized or demineralized whey, whey permeate, rennet casein, buttermilk) to selected quality parameters and digestibility of milk proteins in kefir. Kefir samples analyzed in the study were prepared under laboratory conditions with three industrial bacterial starter cultures. They were examined microbiologically (lactobacilli, lactococci, yeast) and for pH, total protein content, hardness, adhesiveness, water-holding capacity (WHC), and protein digestibility (using two in vitro methods along with the determination of the content of available lysine and glycine). The counts of lactococci and lactobacilli were estimated at levels above 7 and 6 log(CFU/mL), respectively. Yeast was not found in the kefir samples. The pH value of the samples was 4.4–5.2. The pH, hardness, adhesiveness, and WHC were dependent on the type of kefir starter culture and the type of milk protein powder added. Each protein preparation added increased the amount of available lysine and glycine. However, when converted for 1 g of kefir protein, the changes in the content of available lysine and glycine were variable and depended on both the milk protein powder and starter culture used.

scholarly journals Functional strain redundancy and persistent phage infection in Swiss hard cheese starter cultures

2021 ◽  
Author(s):  
Vincent Somerville ◽  
Hélène Berthoud ◽  
Remo S. Schmidt ◽  
Hans-Peter Bachmann ◽  
Yi Hélène Meng ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Evolutionary Dynamics ◽  
Temporal Dynamics ◽  
Negative Impact ◽  
Bacterial Species ◽  
Starter Culture ◽  
Streptococcus Thermophilus ◽  
Starter Cultures ◽  
Lactobacillus Delbrueckii ◽  
Shotgun Metagenomics

AbstractUndefined starter cultures are poorly characterized bacterial communities from environmental origin used in cheese making. They are phenotypically stable and have evolved through domestication by repeated propagation in closed and highly controlled environments over centuries. This makes them interesting for understanding eco-evolutionary dynamics governing microbial communities. While cheese starter cultures are known to be dominated by a few bacterial species, little is known about the composition, functional relevance, and temporal dynamics of strain-level diversity. Here, we applied shotgun metagenomics to an important Swiss cheese starter culture and analyzed historical and experimental samples reflecting 82 years of starter culture propagation. We found that the bacterial community is highly stable and dominated by only a few coexisting strains of Streptococcus thermophilus and Lactobacillus delbrueckii subsp. lactis. Genome sequencing, metabolomics analysis, and co-culturing experiments of 43 isolates show that these strains are functionally redundant, but differ tremendously in their phage resistance potential. Moreover, we identified two highly abundant Streptococcus phages that seem to stably coexist in the community without any negative impact on bacterial growth or strain persistence, and despite the presence of a large and diverse repertoire of matching CRISPR spacers. Our findings show that functionally equivalent strains can coexist in domesticated microbial communities and highlight an important role of bacteria-phage interactions that are different from kill-the-winner dynamics.

scholarly journals Technological and Safety Characterization of Kocuria rhizophila Isolates From Traditional Ethnic Dry-Cured Ham of Nuodeng, Southwest China

2021 ◽  
Vol 12 ◽  
Author(s):  
Qiao Shi ◽  
Xinrui Wang ◽  
Zijing Ju ◽  
Biqin Liu ◽  
Changwei Lei ◽  
...  
Keyword(s):  
Amino Acid ◽  
Antimicrobial Resistance ◽  
Starter Culture ◽  
Starter Cultures ◽  
Acid Decarboxylase ◽  
Decarboxylase Activity ◽  
Amino Acid Decarboxylase ◽  
Processing Techniques ◽  
Kocuria Rhizophila

Nuodeng ham is known for its unique processing techniques and flavor. In the present study, proteolytic microorganisms from cured artisanal Nuodeng ham were investigated in order to identify and select potential starter cultures for its faster and safer fermentation. Eight isolates, accounting for 57% of proteolytic microorganisms, were found to be related to Kocuria rhizophila. Relevant properties of K. rhizophila as potential starter culture were evaluated in vitro for the first time. Intra-species diversities were found in phylogenetic and physiological properties of K. rhizophila isolates. Nevertheless, desirable attributes, such as halo-tolerance, nitrate reductase and protease activity, as well as the absence of antimicrobial resistance and amino acid decarboxylase activity, were observed in selected isolates. Moreover, genome analysis of isolates K24 and K45 confirmed their lack of typical genes for virulence, antimicrobial resistance and amino acid decarboxylase. K. rhizophila may thus represent a novel starter candidate of coagulase-negative cocci group and contribute to color and flavor development of fermented meats.

scholarly journals Physicochemical and Microbial Characteristics of Yogurt with Added Saccharomyces Boulardii

2017 ◽  
Vol 5 (3) ◽  
pp. 300-307 ◽  
Author(s):  
Alaa Niamah
Keyword(s):  
Proteolytic Activity ◽  
Storage Time ◽  
Starter Culture ◽  
Control Sample ◽  
Streptococcus Thermophilus ◽  
Saccharomyces Boulardii ◽  
Starter Cultures ◽  
Lactobacillus Bulgaricus ◽  
Fermentation Time ◽  
Ph Values

The effect of adding Saccharomyces boulardii on yogurt quality was studied. Yogurt control was made using whole cow’s milk and classic starter culture. Other three treatments of yogurt were made by adding 1%,2% and 3% of Saccharomyces boulardii with yogurt starter. pH values and proteolytic activity of all yogurt treatments were determined during fermentation time. Changes in physicochemical and microbial properties of yogurt product were observed during storage time (21 days at 4°C). Yogurt samples with added yeast to starter cultures showed a slight increase in pH values during the 6 hours of fermentation. After fermentation time, pH and proteolytic activity of yogurt with 3% yeast were 4.05 and 250 μg/ml while control sample was 4.22 and 200 μg/ml respectively. pH, TN, WSN, TVFA and WHC values of yogurt with Saccharomyces boulardii were slightly increased whereas decreased the STS percentage compare with control yogurt without yeast during storage time. The addition of Saccharomyces boulardii improved the survivability of bacterial starter culture. After 21 day, Saccharomyces boulardii counts were 5.78, 6.01 and 6.31 Log. CFU/gm for yogurt with 1%,2% and 3% yeast respectively whereas Log. lactic acid bacteria of yogurt with 3% yeast was 7.53 and 7.55 for Lactobacillus bulgaricus and Streptococcus thermophilus.

Dairy lactococcal and streptococcal phage–host interactions: an industrial perspective in an evolving phage landscape

2020 ◽  
Vol 44 (6) ◽  
pp. 909-932
Author(s):  
Dennis A Romero ◽  
Damian Magill ◽  
Anne Millen ◽  
Philippe Horvath ◽  
Christophe Fremaux
Keyword(s):  
Negative Impact ◽  
Starter Culture ◽  
Starter Cultures ◽  
Host Recognition ◽  
Host Interactions ◽  
Industry Research ◽  
Host Relationships ◽  
Dairy Starter Cultures ◽  
Fermented Dairy ◽  
Dairy Starter

ABSTRACT Almost a century has elapsed since the discovery of bacteriophages (phages), and 85 years have passed since the emergence of evidence that phages can infect starter cultures, thereby impacting dairy fermentations. Soon afterward, research efforts were undertaken to investigate phage interactions regarding starter strains. Investigations into phage biology and morphology and phage–host relationships have been aimed at mitigating the negative impact phages have on the fermented dairy industry. From the viewpoint of a supplier of dairy starter cultures, this review examines the composition of an industrial phage collection, providing insight into the development of starter strains and cultures and the evolution of phages in the industry. Research advances in the diversity of phages and structural bases for phage–host recognition and an overview of the perpetual arms race between phage virulence and host defense are presented, with a perspective toward the development of improved phage-resistant starter culture systems.

scholarly journals The Use of Lactic Acid Bacteria Starter Culture in the Production ofNunu, a Spontaneously Fermented Milk Product in Ghana

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Fortune Akabanda ◽  
James Owusu-Kwarteng ◽  
Kwaku Tano-Debrah ◽  
Charles Parkouda ◽  
Lene Jespersen
Keyword(s):  
Amino Acids ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Starter Culture ◽  
Antimicrobial Activities ◽  
Starter Cultures ◽  
Lactobacillus Helveticus ◽  
Milk Product ◽  
Technological Properties

Nunu, a spontaneously fermented yoghurt-like product, is produced and consumed in parts of West Africa. A total of 373 predominant lactic acid bacteria (LAB) previously isolated and identified fromNunuproduct were assessedin vitrofor their technological properties (acidification, exopolysaccharides production, lipolysis, proteolysis and antimicrobial activities). Following the determination of technological properties,Lactobacillus fermentum22-16,Lactobacillus plantarum8-2,Lactobacillus helveticus22-7, andLeuconostoc mesenteroides14-11 were used as single and combined starter cultures forNunufermentation. Starter culture fermentedNunusamples were assessed for amino acids profile and rate of acidification and were subsequently evaluated for consumer acceptability. For acidification properties, 82%, 59%, 34%, and 20% of strains belonging toLactobacillus helveticus, L. plantarum, L. fermentum, andLeu. mesenteriodes, respectively, demonstrated fast acidification properties. High proteolytic activity (>100 to 150 μg/mL) was observed for 50%Leu. mesenteroides,40%L. fermentum,41%L. helveticus, 27%L. plantarum,and 10%Ent. faeciumspecies. In starter culture fermentedNunusamples, all amino acids determined were detected inNunufermented with single starters ofL. plantarumandL. helveticusand combined starter ofL. fermntumandL. helveticus. Consumer sensory analysis showed varying degrees of acceptability forNunufermented with the different starter cultures.

scholarly journals Effect of Traditional Dried Starter Culture on Morphological, Chemical and Physicochemical Properties of Sweet Fermented Glutinous Rice Products

2019 ◽  
Vol 11 (6) ◽  
pp. 43
Author(s):  
Vipa Surojanametakul ◽  
Wanchai Panthavee ◽  
Prajongwate Satmalee ◽  
Naraporn Phomkaivon ◽  
Tadashi Yoshihashi
Keyword(s):  
Microbial Growth ◽  
Starter Culture ◽  
Starter Cultures ◽  
Soluble Solids ◽  
Plate Count ◽  
Morphological Examination ◽  
Alcohol Content ◽  
Fermentation Time ◽  
Rice Grains ◽  
Glutinous Rice

Sweet glutinous rice products or khao-mak in Thai were prepared by fermenting cooked glutinous rice (RD6 variety) using traditional starter cultures from Samut Sakhon (SSK) and Pathum Thani (PTT) Provinces at room temperature (28±2 °C) for 3 days. Amylolytic activities of microbial excisting in the traditional starter cultures were tested. Meanwhile, types and amounts of microbial growth in fermented rice products were investigated. Both traditional dried starter cultures showed strong amylolytic activity after inoculation for 2 and 3 days in starch agar. Microbiological profiles of rice fermentation were varied in total plate count, yeast and molds over the fermentation period. Different starter cultures resulted in a wide variation of end products with diverse chemical, microbiological and morphology properties; however those changes exhibited similar trends in all treatments. As fermentation time increased, protein content remained unchanged while total soluble solids, pH, acidity, sugar and alcohol content markedly increased compared with unfermented cooked rice. PTT showed products with higher acidity and alcohol content (0.50%, 2.58%) than SSK (0.31%, 1.85%). Morphological examination of rice grains revealed that microbial growth started from the outer surface and then moved inside the rice grains with greater corrosion was observed as fermentation time increased. Pasting and gelatinization properties of the rice flour were also strongly affected by fermentation.

scholarly journals The Presence of Salt and a Curing Agent Reduces Bacteriocin Production by Lactobacillus sakei CTC 494, a Potential Starter Culture for Sausage Fermentation

1999 ◽  
Vol 65 (12) ◽  
pp. 5350-5356 ◽  
Author(s):  
Frédéric Leroy ◽  
Luc de Vuyst
Keyword(s):  
Sodium Chloride ◽  
Sodium Nitrite ◽  
Starter Culture ◽  
Cell Formation ◽  
Bacteriocin Production ◽  
Starter Cultures ◽  
Lactobacillus Sakei ◽  
Primary Metabolite ◽  
Fermented Sausages

ABSTRACT The specific conditions in the batter of raw fermented sausages may reduce the efficiency of bacteriocin-producing starter cultures. In this work, using in vitro fermentation, we found that sodium chloride and sodium nitrite interfere with the growth ofLactobacillus sakei CTC 494, an organism which produces the antilisterial bacteriocin sakacin K. Because sakacin K production follows primary metabolite kinetics, a decrease in cell formation resulted in a decrease in sakacin K production as well. Sodium chloride dramatically influenced bacteriocin production by decreasing both biomass production and specific bacteriocin production. Sodium nitrite, however, had no effect on specific bacteriocin production and decreased bacteriocin production only because of its effect on cell growth. Moreover, sodium nitrite enhanced the toxic effect of lactic acid on bacterial growth.

Technological properties of indigenous Lactococcus lactis strains isolated from Lait caillé, a spontaneous fermented milk from Burkina Faso

2020 ◽  
Vol 87 (1) ◽  
pp. 110-116 ◽  
Author(s):  
Geoffroy Romaric Bayili ◽  
Pernille Greve Johansen ◽  
Anni Bygvrå Hougaard ◽  
Bréhima Diawara ◽  
Georges Anicet Ouedraogo ◽  
...  
Keyword(s):  
Lactococcus Lactis ◽  
Cold Storage ◽  
Starter Culture ◽  
Fermented Milk ◽  
Starter Cultures ◽  
Technological Properties ◽  
Fermentation Time ◽  
Physiological Tests ◽  
Culture Development ◽  
The Impact

AbstractThe experiments reported in this research paper aimed to determine the technological properties of indigenous Lactococcus lactis strains isolated from Lait caillé, a spontaneous fermented milk, from the perspective of starter culture development. Fermentations were conducted to determine the acidification patterns. The ropy character, growth in 0.04 g/ml NaCl and citrate metabolism were additionally tested. Furthermore, the rheological properties of samples from selected strains and the impact of cold storage were evaluated. Based on the rate of acidification, the indigenous strains were divided into 2 groups depending on their fermentation time, i.e. 10–13 h (fast acidifier), and up to 72 h (slow acidifier), respectively. The physiological tests suggested that most of these strains produced exopolysaccharides but none could ferment citrate. The flow properties of the samples inoculated by the fast acidifier strains showed a time-dependent shear thinning behaviour, while their viscoelastic properties corresponded structurally to those of weak gels. Cold storage decreased the viscosity and CFU counts for most of the indigenous strains tested. This study is a step towards the definition of starter cultures for African spontaneous fermented milks such as Lait caillé.

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