scholarly journals Massive Survey on Bacterial–Bacteriophages Biodiversity and Quality of Natural Whey Starter Cultures in Trentingrana Cheese Production

2021 ◽  
Vol 12 ◽  
Author(s):  
Andrea Mancini ◽  
Maria Cid Rodriguez ◽  
Miriam Zago ◽  
Nicola Cologna ◽  
Andrea Goss ◽  
...  
Keyword(s):  
Bacterial Species ◽  
Resistance Mechanisms ◽  
Starter Cultures ◽  
Lactobacillus Helveticus ◽  
Bacterial Strains ◽  
Turbidity Test ◽  
Plate Counts ◽  
Identification And Characterization ◽  
Cheese Production

This study focused on the microbial and bacteriophages identification and characterization in cheese-production facilities that use natural whey starter (NWS) cultures for Trentingrana production. Bacterial and phage screening was carried out on cooked not acidified whey and NWS samples isolated from six dairy factories, for 4 consecutive days in four different months. By means of a combined approach, using plate counts, bacterial isolation, and metataxonomic analysis Lactobacillus helveticus was found occurring as the dominant species in NWS cultures and Levilactobacillus brevis as codominant in the cheese factories where the temperature of NWS production was mainly lower than 40°C, suggesting that the variability in the parameters of the NWS culture preparation could differently modulate the bacterial species in NWS cultures. Using turbidity test approach on 303 bacterial isolates from the NWS cultures, 120 distinct phages were identified. L. helveticus phage contamination of NWS cultures was revealed in most of the analyzed samples, but despite the great recovery of bacteriophage contamination cases, the microbial quality of NWS cultures was high. Our results support the presence of natural bacteriophage resistance mechanisms in L. helveticus. The use of NWS cultures probably creates an ideal environment for the proliferation of different L. helveticus strains balanced with their phages without a clear dominance. It is evident, from this study, that the presence of a high biodiversity of NWS bacterial strains is relevant to avoid phages dominance in NWS cultures and consequently to keep a good acidification ability.

scholarly journals In Silico Prediction of Horizontal Gene Transfer Events in Lactobacillus bulgaricus and Streptococcus thermophilus Reveals Protocooperation in Yogurt Manufacturing

2009 ◽  
Vol 75 (12) ◽  
pp. 4120-4129 ◽  
Author(s):  
Mengjin Liu ◽  
Roland J. Siezen ◽  
Arjen Nauta
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Gene Cluster ◽  
In Silico ◽  
Bacterial Species ◽  
Streptococcus Thermophilus ◽  
Starter Cultures ◽  
Lactobacillus Helveticus ◽  
Lactobacillus Bulgaricus ◽  
Genetic Level

ABSTRACT Lactobacillus bulgaricus and Streptococcus thermophilus, used in yogurt starter cultures, are well known for their stability and protocooperation during their coexistence in milk. In this study, we show that a close interaction between the two species also takes place at the genetic level. We performed an in silico analysis, combining gene composition and gene transfer mechanism-associated features, and predicted horizontally transferred genes in both L. bulgaricus and S. thermophilus. Putative horizontal gene transfer (HGT) events that have occurred between the two bacterial species include the transfer of exopolysaccharide (EPS) biosynthesis genes, transferred from S. thermophilus to L. bulgaricus, and the gene cluster cbs-cblB(cglB)-cysE for the metabolism of sulfur-containing amino acids, transferred from L. bulgaricus or Lactobacillus helveticus to S. thermophilus. The HGT event for the cbs-cblB(cglB)-cysE gene cluster was analyzed in detail, with respect to both evolutionary and functional aspects. It can be concluded that during the coexistence of both yogurt starter species in a milk environment, agonistic coevolution at the genetic level has probably been involved in the optimization of their combined growth and interactions.

Influence of milk quality and production protocol on proteolysis and lipolysis in Monti Dauni Meridionali Caciocavallo cheese

2010 ◽  
Vol 77 (4) ◽  
pp. 385-391 ◽  
Author(s):  
Marzia Albenzio ◽  
Antonella Santillo ◽  
Donatella Esterina Russo ◽  
Mariangela Caroprese ◽  
Rosaria Marino ◽  
...  
Keyword(s):  
Southern Italy ◽  
Dairy Farms ◽  
Starter Cultures ◽  
The Other ◽  
Cow Milk ◽  
Factors Influencing ◽  
Neighbouring Area ◽  
Main Factors ◽  
Cheese Production

The aim of this study was to assess the effect of milk source and of cheese production protocol on proteolytic and lipolytic pattern of cheese during ripening. The study involved six dairy factories located in Monti Dauni Meridionali area of Southern Italy; three dairy factories processed the milk produced by their own cow herds, while the other three dairy factories processed the milk collected in other dairy farms located in the neighbouring area. Cow milk processed to cheese had different nutritional parameters and hygienic quality. Caciocavallo cheese showed differences in the evolution of proteolysis during ripening and in the intensity of the lipolytic process detected at the end of ripening. The main factors influencing Caciocavallo cheese features were the quality of the starting milk, differences in technological steps such as milk heating, type of starter cultures and coagulant used.

scholarly journals Autochthonous Natural Starter Cultures: A Chance to Preserve Biodiversity and Quality of Pecorino Romano PDO Cheese

2021 ◽  
Vol 13 (15) ◽  
pp. 8214
Author(s):  
Luigi Chessa ◽  
Antonio Paba ◽  
Elisabetta Daga ◽  
Ilaria Dupré ◽  
Carlo Piga ◽  
...  
Keyword(s):  
Streptococcus Thermophilus ◽  
Starter Cultures ◽  
Lactobacillus Delbrueckii ◽  
Scale Production ◽  
Physico Chemical ◽  
Sensory Analyses ◽  
Different Strains ◽  
Industrial Scale Production ◽  
Cheese Production

During Pecorino Romano PDO cheese production, scotta (residual whey from ricotta cheese manufacturing) or siero (whey) can be integrated with autochthonous starters, natural and composed of an indefinite number of species and strains, or commercial selected starters to obtain scotta/siero-innesto. In this study, three biodiverse autochthonous natural starter cultures (SR30, SR56, and SR63) belonging to the Agris Sardegna BNSS microbial collection, composed of different strains belonging to the species Streptococcus thermophilus, Lactobacillus delbrueckii subsp. bulgaricus, Enterococcus faecium, and Limosilactobacillus reuteri were lyophilized and combined into two starter mixes (A and B). The scotta/siero-innesto and the Pecorino Romano obtained using natural starters were compared with those obtained using commercial selected starters during three seasons of the cheesemaking campaign. Different pH and microbial compositions for the scotta/siero-innesto obtained using natural or commercial starters were found, attributable to their different biodiversity. The six-month-ripened cheese microbiota was influenced mostly by the season of cheesemaking, whereas physico-chemical and sensory analyses did not highlight differences among the products obtained. In general, no effect attributable to the type of scotta/siero-innesto used was observed, allowing the conclusion that natural starter cultures can be used also in industrial-scale production, ensuring high stability in the technological performances and preserving the microbial, chemical, and sensory characteristics of Pecorino Romano PDO cheese.

Application of membrane technology in the pretreatment of cheese dairies wastes and co-treatment in a municipal conventional biological unit

1997 ◽  
Vol 36 (2-3) ◽  
pp. 361-367 ◽  
Author(s):  
Eleftheria Papachristou ◽  
Costas T. Lafazanis
Keyword(s):  
Cheese Whey ◽  
Treatment Plant ◽  
Membrane Technology ◽  
Biological Unit ◽  
Urban Sewage ◽  
Dairy Wastes ◽  
Starting Point ◽  
Quality Of Milk ◽  
Cheese Production

A great number of cheese dairies and dairy industries in Greece are disposing their wastes, mainly cheese whey, either on land or in surface receivers, in large quantities creating a major environmental problem. A typical agricultural and pastoral provincial town of 70,000 inhabitants, Trikala, became the starting point of this research. A co-treatment of the urban sewage and the dairy wastes in the municipal treatment plant was recommended. The successful application of the above statement is based primarily on the pretreatment of the cheese dairies wastes. So far for cheese whey the recovery of the lactose serum in the contemporary central unit applying membrane technology has been suggested. As far as the wastewaters of the washing and refrigeration are concerned a pretreatment is required for the defatting in a grease trap, the grating, the adjustment of pH and the equalisation in an appropriate tank. Finally, this research has also focussed on the importance of membrane technology in improving the quality of milk and cheese production.

Antimicrobial properties of actively purified secondary metabolites isolated from different marine organisms

2020 ◽  
Vol 21 ◽  
Author(s):  
Nilushi Indika Bamunu Arachchige ◽  
Fazlurrahman Khan ◽  
Young-Mog Kim
Keyword(s):  
Secondary Metabolites ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Bacterial Species ◽  
Antimicrobial Properties ◽  
Antimicrobial Effect ◽  
Cost Effective ◽  
Resistance Mechanisms ◽  
Marine Organisms ◽  
Antimicrobial Compounds

Background: The treatment of infection caused by pathogenic bacteria becomes one of the serious concerns globally. The failure in the treatment was found due to the exhibition of multiple resistance mechanisms against the antimicrobial agents. Emergence of resistant bacterial species has also been observed due to prolong treatment using conventional antibiotics. To combat these problems, several alternative strategies have been employed using biological and chemically synthesized compounds as antibacterial agents. Marine organisms considered as one of the potential sources for the isolation of bioactive compounds due to the easily available, cost-effective, and eco-friendly. Methods: The online search methodology was adapted for the collection of information related to the antimicrobial properties of marine-derived compounds. These compound has been isolated and purified by different purification techniques, and their structure also characterized. Furthermore, the antibacterial activities have been reported by using broth microdilution as well as disc diffusion assays. Results: The present review paper describes the antimicrobial effect of diverse secondary metabolites which are isolated and purified from the different marine organisms. The structural elucidation of each secondary metabolite has also been done in the present paper, which will help for the in silico designing of the novel and potent antimicrobial compounds. Conclusion: A thorough literature search has been made and summarizes the list of antimicrobial compounds that are isolated from both prokaryotic and eukaryotic marine organisms. The information obtained from the present paper will be helpful for the application of marine compounds as antimicrobial agents against different antibiotic-resistant human pathogenic bacteria.

Survey on the phage resistance mechanisms displayed by a dairy Lactobacillus helveticus strain

2017 ◽  
Vol 66 ◽  
pp. 110-116 ◽  
Author(s):  
Miriam Zago ◽  
Luigi Orrù ◽  
Lia Rossetti ◽  
Antonella Lamontanara ◽  
Maria Emanuela Fornasari ◽  
...  
Keyword(s):  
Resistance Mechanisms ◽  
Lactobacillus Helveticus ◽  
Phage Resistance

scholarly journals Chromatographic Characterization and In Vitro Bioactivity Evaluation of Lactobacillus helveticus Hydrolysates upon Fermentation of Different Substrates

2021 ◽  
Vol 11 (2) ◽  
pp. 811
Author(s):  
Federica Ianni ◽  
Alessandra Anna Altomare ◽  
Beniamino T. Cenci-Goga ◽  
Francesca Blasi ◽  
Luca Grispoldi ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Proteolytic Activity ◽  
Bioactive Peptides ◽  
Biological Activities ◽  
Skim Milk ◽  
Brain Heart Infusion ◽  
Starter Cultures ◽  
Lactobacillus Helveticus ◽  
Food Sources

Among various food sources, milk proteins remain the major vector for functional peptides endowed with several biological activities. Particularly, the proteolytic activity of lactic acid bacteria during milk fermentation has been one of the most followed strategies to produce bioactive peptides. In the present study, the exploration of the activity of several starter cultures, at different fermentation times, was firstly investigated by reversed phase-high performance liquid chromatography. Among the tested strains, Lactobacillus helveticus showed a higher proteolytic activity and it was submitted to further investigations by changing the fermentation substrate (skim milk, brain heart infusion, peptone water) as well as the extraction strategy (trichloroacetic acid vs. glass beads). The chromatographic analyses and the in vitro antioxidant and antihypertensive assays highlighted considerable differences for L. helveticus hydrolysates from different substrates, while a negligible impact by the two extraction protocols emerged. Furthermore, nano-high pressure liquid chromatography coupled with a high resolution mass spectrometry analyzer allowed the preliminary discrimination of fractions from fermented skim milk, likely responsible for the found activity. The obtained results suggest the possibility of varying the fermentation parameters in order to maximize the functional effects of the bioactive peptides.

scholarly journals The Conservation of Low Complexity Regions in Bacterial Proteins Depends on the Pathogenicity of the Strain and Subcellular Location of the Protein

Genes ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 451
Author(s):  
Pablo Mier ◽  
Miguel A. Andrade-Navarro
Keyword(s):  
Membrane Proteins ◽  
Outer Membrane ◽  
Bacterial Species ◽  
Outer Membrane Proteins ◽  
Subcellular Location ◽  
Low Complexity ◽  
Extracellular Proteins ◽  
Bacterial Strains ◽  
Bacterial Proteins ◽  
Protein Subcellular Location

Low complexity regions (LCRs) in proteins are characterized by amino acid frequencies that differ from the average. These regions evolve faster and tend to be less conserved between homologs than globular domains. They are not common in bacteria, as compared to their prevalence in eukaryotes. Studying their conservation could help provide hypotheses about their function. To obtain the appropriate evolutionary focus for this rapidly evolving feature, here we study the conservation of LCRs in bacterial strains and compare their high variability to the closeness of the strains. For this, we selected 20 taxonomically diverse bacterial species and obtained the completely sequenced proteomes of two strains per species. We calculated all orthologous pairs for each of the 20 strain pairs. Per orthologous pair, we computed the conservation of two types of LCRs: compositionally biased regions (CBRs) and homorepeats (polyX). Our results show that, in bacteria, Q-rich CBRs are the most conserved, while A-rich CBRs and polyA are the most variable. LCRs have generally higher conservation when comparing pathogenic strains. However, this result depends on protein subcellular location: LCRs accumulate in extracellular and outer membrane proteins, with conservation increased in the extracellular proteins of pathogens, and decreased for polyX in the outer membrane proteins of pathogens. We conclude that these dependencies support the functional importance of LCRs in host–pathogen interactions.

scholarly journals Isolation and efficacy of two bacterial strains antagonists of Erwinia amylovora and Pectobacterium carotovorum

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
M’hamed BENADA ◽  
Boualem BOUMAAZA ◽  
Sofiane BOUDALIA ◽  
Omar KHALADI
Keyword(s):  
Fire Blight ◽  
Erwinia Amylovora ◽  
Bacterial Species ◽  
Crop Protection ◽  
Soft Rot ◽  
Causal Agent ◽  
Plant Diseases ◽  
Ecological Niches ◽  
Pectobacterium Carotovorum ◽  
Bacterial Strains

Abstract Background The development of ecofriendly tools against plant diseases is an important issue in crop protection. Screening and selection process of bacterial strains antagonists of 2 pathogenic bacterial species that limit very important crops, Erwinia amylovora, the causal agent of the fire blight disease, and Pectobacterium carotovorum, the causal agent of bacterial potato soft rot, were reported. Bacterial colonies were isolated from different ecological niches, where both pathogens were found: rhizosphere of potato tubers and fruits and leaves of pear trees from the northwest region of Algeria. Direct and indirect confrontation tests against strains of E. amylovora and P. carotovorum were performed. Results Results showed a significant antagonistic activity against both phytopathogenic species, using direct confrontation method and supernatants of cultures (p<0.005). In vitro assays showed growth inhibitions of both phytopathogenic species. Furthermore, results revealed that the strains of S. plymuthica had a better inhibitory effect than the strains of P. fluorescens against both pathogens. In vivo results on immature pear fruits showed a significant decrease in the progression of the fire blight symptoms, with a variation in the infection index from one antagonistic strain to another between 31.3 and 50%, and slice of potato showed total inhibition of the pathogen (P. carotovorum) by the antagonistic strains of Serratia plymuthica (p<0.005). Conclusion This study highlighted that the effective bacteria did not show any infection signs towards plant tissue, and considered as a potential strategy to limit the fire blight and soft rot diseases.

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