Lactic acid bacteria as a starter culture are very important component in the fermentation process of dairy and food industry. Application of lactic acid bacteria as probiotic bacteria adds more ...functionality to the developed product. Gut colonizing bacteria have attractive benefits related to human health. Bio-functional properties such as antimicrobial activity, anti-inflammatory, ACE-inhibitory, antioxidant, antidiarrheal, antiviral, immunomodulatory, hypocholesterolemic, anti-diabetic and anti-cancer activities are the most applicable research areas of lactic acid bacteria. Different strains of Lactobacillus are generally consumed as probiotics and colonize the gastrointestinal tract. Sometimes these bacteria may possess antimicrobial activity and may positively influence the effect of antibiotics. Use of Lactobacillus spp. for the development of functional foods is one of the promising areas of current research and applications. Individual bacterial species have unique biological activity, which may vary from strains to strains and identification of this uniqueness could be helpful in the development of functional and therapeutic food products.
In this review, we aim to describe the mechanisms by which LAB can fulfil the novel role of efficient cell factory for the production of functional biomolecules and food ingredients to enhance the ...quality of cereal-based beverages. LAB fermentation is a safe, economical, and traditional method of food preservation foremost, as well as having the additional benefits of flavor, texture, and nutrition amelioration. Additionally, LAB fermentation in known to render cereal-based foods and beverages safe, in a chemical-free, consumer-friendly manner, from an antinutrient and toxigenic perspective. Huge market opportunities and potential exist for food manufacturers who can provide the ideal functional beverage fulfilling consumer needs. Newly developed fermented cereal-based beverages must address markets globally including, high-nutrition markets (developing countries), lifestyle choice consumers (vegetarian, vegan, low-fat, low-salt, low-calorie), food-related non-communicable disease sufferers (cardiovascular disease, diabetes), and green label consumers (Western countries). To fulfil these recommendations, a suitable LAB starter culture and cereal-based raw materials must be developed. These strains would be suitable for the biopreservation of cereal beverages and, ideally, would be highly antifungal, anti-mycotoxigenic, mycotoxin-binding and proteolytic (neutralize toxic peptides and release flavor-contributing amino acids) with an ability to ferment cereals, whilst synthesizing oligosaccharides, thus presenting a major opportunity for the development of safe cereal-based prebiotic functional beverages to compete with and replace the existing dairy versions.
This review examines the different types of interactions between the microorganisms involved in the fermentation processes of alcoholic beverages produced all over the world from cereals or fruit ...juices. The alcoholic fermentation converting sugars into ethanol is usually carried out by yeasts, mainly Saccharomyces cerevisiae, which can grow directly using fruit sugars, such as those in grapes for wine or apples for cider, or on previously hydrolyzed starch of cereals, such as for beers. Some of these beverages, or the worts obtained from cereals, can be distilled to obtain spirits. Besides S. cerevisiae, all alcoholic beverages can contain other microorganisms and especially in spontaneous fermentation when starter cultures are not used. These other microbes are mostly lactic acid bacteria and other yeasts-the non-Saccharomyces yeasts. The interactions between all these microorganisms are very diverse and complex, as in any natural occurring ecosystem, including food fermentations. To describe them, we have followed a simplified ecological classification of the interactions. The negative ones are amensalism, by which a metabolic product of one species has a negative effect on others, and antagonism, by which one microbe competes directly with others. The positive interactions are commensalism, by which one species has benefits but no apparent effect on others, and synergism, by which there are benefits for all the microbes and also for the final product. The main interactions in alcoholic beverages are between S. cerevisiae and non-Saccharomyces and between yeasts and lactic acid bacteria. These interactions can be related to metabolites produced by fermentation such as ethanol, or to secondary metabolites such as proteinaceous toxins, or are feed-related, either by competition for nutrients or by benefit from released compounds during yeast autolysis. The positive or negative effects of these interactions on the organoleptic qualities of the final product are also revised. Focusing mainly on the alcoholic beverages produced by spontaneous fermentations, this paper reviews the interactions between the different yeasts and lactic acid bacteria in wine, cider, beer, and in spirits such as tequila, mezcal and cachaça.
Fermented milks are a source of bioactive peptides with different potential benefits on human health and may be considered as functional foods. Sheep milk and fermented milk have been collected and a ...biochemical characterization, by a proteomic approach, GC/MS and microtiter plate assay methods, have been conducted to evaluate their peptide, fatty acid and aromatic profile, and to assess potential health promoting effects. Furthermore, a comparison between sheep-fermented milk (SFM) made with commercial starter cultures and YoAlp®, a sheep-fermented milk obtained using local strains of lactic acid bacteria, has been performed. Peptide’s profile comparison shows a higher number of amino acidic frequencies using autochthonous starter cultures than commercial ones. Among these peptides, 20.78% and 29.87%, respectively, are supposed to be potentially bioactive. Furthermore, in both products, the fatty acid profile was similar to that of origin sheep milk, and concerning aromatic profile, YoAlp® shows yogurt typical aromatic assets. Considering bioactivity, ACE inhibitor activity is high for both samples. Similar values, as expected by peptide profile analysis, have been obtained. Even in the case of antioxidant capacity, peptide profile bioactivity prediction has been confirmed by the assay showing a DPPH inhibition higher for SFM than for YoAlp®, but this difference is not statistically significant. Local strains of lactic acid bacteria seem to work as well as the commercial, preserving biodiversity and typicality. However, further analyses are needed to understand microbial proteolytic activities and to investigate gastric digestion resistance of bioactive peptides.
The aim of this study was to investigate the temporal stability of microbial contamination during cheddar cheese production by examining patterns of nonstarter bacteria in 60-day aged cheddar ...collected from the start and end of 30 consecutive production days. Further, we explored the source of these temporal microbial variations by comparing microbial communities in the aged cheese to those on food contact surfaces from a piece of cheesemaking equipment previously identified as a major source of nonstarter bacteria in the same processing environment. 16S rRNA metabarcoding and culture-based sequencing methods identified two Streptococcus sequence variants significantly associated with the end of the production day in both the aged cheese and the cheese processing environment. Closer inspection of these sequence variants in the aged cheese over the 40-day sampling period revealed sinusoidal-like fluctuations in their relative ratios, which appeared to coincide with the
starter rotation schedule. These results demonstrate that the microbial composition of finished cheese can vary according to the timing of processing within a production day. Further, our results demonstrate that time-of-day microbial differences in cheese can result from bacterial growth on food contact surfaces and that the composition of these microbial differences is subject to change day-to-day and may be linked to routine changes in the
starter culture.
Long production schedules used in modern cheese manufacturing can create circumstances that support the growth of microorganisms in the cheese processing environment. This work demonstrates that this growth can lead to significant changes in the microbial quality of aged cheese produced later in the production day. Further, we demonstrate that the dominant bacteria associated with these microbial changes throughout production are subject to change between days and might be influenced by specific cheese manufacturing practices. These findings improve understanding of microbial contamination patterns in modern food manufacturing facilities, thereby improving our ability to develop strategies to minimize quality losses due to microbial spoilage.
Bacillus subtilis, a valuable industrial microorganism used in starter cultures in soybean fermentation, is a species of bacteria with interspecies diversity. Here, four multilocus sequence typing ...(MLST) schemes developed to assess the diversity of B. subtilis or Bacillus spp. were applied and compared to confirm the interspecies diversity of B. subtilis. In addition, we analyzed correlations between amino acid biosynthesis genes and sequence types (STs); this is important because amino acids are key taste components in fermented foods. On applying the four MLST methods to 38 strains and the type strain of B. subtilis, 30 to 32 STs were identified. The discriminatory power was 0.362-0.964 for the genes used in the MLST methods; the larger the gene, the greater the number of alleles and polymorphic sites. All four MLST methods showed a correlation between STs and strains that do not possess the hutHUIG operon (which contains genes required for the production of glutamate from histidine). This correlation was verified using 168 further genome-sequence strains.
Fermented shrimp paste (Kapi) is traditionally produced using a high content of salt and mainly consumed as a food condiment by the Thai people. In order to select potential functional autochthonous ...starter culture, the protease-producing bacteria from Kapi were isolated, screened, and evaluated for technological and safety aspects. Among 195 isolates, five bacterial strains (MSK-3P, MSK-4P, MSK-5P, MSK-7P, and MSK-10P) exhibited the highest activity of protease using Anson method. All of them were identified as Virgibacillus halodenitrificans using 16S rRNA sequence analysis. All selected strains exhibited growth in the presence of NaCl up to 25%. Neither strain showed hemolytic activity nor biogenic amine formation. Among all selected strains, only strain MSK-10P had no ability to form a biofilm, while four other strains showed a weak ability. Strain MSK-7P exhibited multiple resistances to tetracycline and vancomycin, while strains MSK-3P, MSK-4P, and MSK-10P showed susceptibility to all antibiotics tested. According to the obtained results, this protease-producing V. halodenitrificans MSK-10P is a good candidate for further investigation for use in Kapi fermentation to assess its technological performance as a autochthonous starter culture.
Macrococcus
spp. are Gram-positive cocci that belong to the
Staphylococcaceae
family; they are closely related to staphylococci, but, unlike staphylococci, they are not considered as human pathogens.
...Macrococcus
spp. are recognized as relevant veterinary pathogens, and their presence has been reported in food products of animal origin.
Macrococcus caseolyticus
, the most studied species of the
Macrococcus
genus, is associated with the development of aroma and flavor in fermented foods and is, thus, used as starter cultures in fermentations. However, certain important issues regarding food safety must be taken into account when employing these microorganisms in fermentations. Recent studies have reported the presence of genes associated with resistance to methicillin and other antibiotics in
M. caseolyticus
. This can be harmful to human health as these genes can be transferred to other bacteria present in the food, mainly staphylococcal species. This work, therefore, aims to highlight the importance of a more critical view on the presence of macrococci in foods and the possible indirect risks to human health.
AIMS: This study aimed to evaluate the effects of inoculation of strains of lactic acid bacteria (LAB) isolated from sugarcane grown in a Brazil on the quality of corn silage. METHODS AND RESULTS: ...Three strains of Lactobacillus buchneri (UFLA SLM11, UFLA SLM103 and UFLA SLM108), five strains of Lactobacillus plantarum (UFLA SLM08, UFLA SLM41, UFLA SLM45, UFLA SLM46 and UFLA SLM105), and one strain of Leuconostoc mesenteroides (UFLA SLM06) were evaluated at 0, 10, 30, 60 and 90 day after inoculating corn forage. The inoculation of the LAB strains did not influence the chemical composition of the silage, but pH, acetic acid and 1,2‐propanediol were affected by treatment. The silages inoculated with UFLA SLM11 and SLM108 contained the lowest yeast and filamentous fungi counts during fermentation. Bacteria belonging to the Enterobacteriaceae family, Clostridium genus were detected in the silages inoculated with Lact. buchneri UFLA SLM 11, 103 and 108, as shown by DGGE analysis. Silages inoculated with Lact. buchneri UFLA SLM 11 showed higher aerobic stability. CONCLUSIONS: The Lact. buchneri UFLA SLM11 strain was considered promising as a starter culture or inoculant for corn silages. SIGNIFICANCE AND IMPACT OF THE STUDY: The selection of microbial inoculants for each crop promotes improvement of silage quality. Studies on the chemical and microbiological characteristics of silage provide useful information for improving ensiling techniques.
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