scholarly journals The Interactions among Isolates of Lactiplantibacillus plantarum and Dairy Yeast Contaminants: Towards Biocontrol Applications

Fermentation ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 14
Author(s):  
Miloslava Kavková ◽  
Jaromír Cihlář ◽  
Vladimír Dráb ◽  
Olga Bazalová ◽  
Zuzana Dlouhá

Yeast diversity in the cheese manufacturing process and in the cheeses themselves includes indispensable species for the production of specific cheeses and undesired species that cause cheese defects and spoilage. The control of yeast contaminants is problematic due to limitations in sanitation methods and chemicals used in the food industry. The utilisation of lactic acid bacteria and their antifungal products is intensively studied. Lactiplantibacillus plantarum is one of the most frequently studied species producing a wide spectrum of bioactive by-products. In the present study, twenty strains of L. plantarum from four sources were tested against 25 species of yeast isolated from cheeses, brines, and dairy environments. The functional traits of L. plantarum strains, such as the presence of class 2a bacteriocin and chitinase genes and in vitro production of organic acids, were evaluated. The extracellular production of bioactive peptides and proteins was tested using proteomic methods. Antifungal activity against yeast was screened using in vitro tests. Testing of antifungal activity on artificial media and reconstituted milk showed significant variability within the strains of L. plantarum and its group of origin. Strains from sourdoughs (CCDM 3018, K19-3) and raw cheese (L12, L24, L32) strongly inhibited the highest number of yeast strains on medium with reconstituted milk. These strains showed a consistent spectrum of genes belonging to class 2a bacteriocins, the gene of chitinase and its extracellular product 9 LACO Chitin-binding protein. Strain CCDM 3018 with the spectrum of class 2a bacteriocin gene, chitinase and significant production of lactic acid in all media performed significant antifungal effects in artificial and reconstituted milk-based media.

1966 ◽  
Vol 53 (9) ◽  
pp. 227-227 ◽  
Author(s):  
Israel Korc ◽  
Horacio Goyena ◽  
Mario Calcagno ◽  
Eduardo Lasalvia ◽  
Juan P. Wahrmann ◽  
...  

1989 ◽  
Vol 35 (6) ◽  
pp. 935-938 ◽  
Author(s):  
J Toffaletti ◽  
B Abrams

Abstract We have studied, both in vitro and in vivo, the quantitative effects of lactic acid production on concentrations of ionized calcium, bound calcium, pH, bicarbonate, and albumin. To do so, we examined the effects of addition of aqueous solutions of either hydrochloric acid, lactic acid, or lithium lactate to blood; we studied in vitro accumulation by storing blood sealed in tubes at room temperature for 5 h, then exposing the blood to air; and we induced in vivo production of lactic acid in healthy individuals who climbed stairs for 10 min. Lactic acid evidently affects the ionized, protein-bound, and complex-bound calcium concentrations in the following ways: (a) hydrogen ions from lactic acid bind to protein, which decreases protein-bound calcium; (b) lactate chelates calcium ions from free ionized calcium and protein-bound calcium about equally; and (c) the loss of a millimole of bicarbonate, either by exposure of blood to air or by respiratory alkalosis, results in the release of about 7 mumol of calcium ions, which re-equilibrate with both the protein-bound and ionized calcium. Because lactate apparently removes calcium ions directly from albumin, our study indicates that protein-bound calcium readily provides calcium ions that buffer changes in the concentration of ionized calcium.


2015 ◽  
Vol 199 ◽  
pp. 47-54 ◽  
Author(s):  
Jiaxin Zhang ◽  
Ali Movahedi ◽  
Junjie Xu ◽  
Mengyang Wang ◽  
Xiaolong Wu ◽  
...  

Author(s):  
Rihua Xu ◽  
Ren Sa ◽  
Junwei Jia ◽  
Lanlan Li ◽  
Xiao Wang ◽  
...  

The demand for “preservative-free” food products is rising, and biopreservation seems to be a potential alternative to replace or reduce the use of chemical preservatives. This study’s objective was to assess the antifungal activity of lactic acid bacteria (LAB) (n = 98) and the efficacy and applicability of the chosen bioprotective cultures against fungal spoilers in dairy products. First, 14 strains of antifungal strains were preliminarily screened by in vitro tests against Pichia pastoris D3, Aspergillus niger D1, Geotrichum candidum N1, Kluyveromyces marxianus W1, and Penicillium chrysogenum B1 and validated by challenge tests in yogurts, indicating that the fungal-inhibiting activity of LAB was species specific and yogurts fermented with antifungal LAB cultures were more effective in extending the shelf life. Secondly, the chosen 14 LAB strains were identified by the 16SrDNA sequence analysis and carbohydrate fermentation test. The results were as follows: 9 strains were Lactobacillus plantarum , 3 were Lactobacillus paracasei , 1 was Enterococus faecium , and 1 was Lactobacillus rhamnosus. Among them, active L. plantarum N7 was the chosen and studied factor that affects the antifungal activity using the response surface methodology (RSM). Finally, in situ tests were conducted to validate the activity of L. plantarum N7 in actual dairy products (whey beverage). Physicochemical and microbial indices of whey beverage during storage period exhibited that antifungal L. plantarum N7 could slow the fungal growth and be candidates of interest for industrial applications.


1964 ◽  
Vol 47 (2) ◽  
pp. 306-313 ◽  
Author(s):  
Denis Gospodarowicz

ABSTRACT Incubation in vitro of rabbit follicles in separate experiments with dehydroepiandrosterone-14C (DHEA-14C), progesterone-14C and pregnenolone-3H in the presence of FSH gave the following results: 39 % of the radioactivity of DHEA-14C is converted to androstenedione and testosterone, while only 3 % of the radioactivity of either progesterone-14C or pregnenolone-3H is found in the androgen fraction. From the ratio of testosterone to androstenedione formed from the three precursors, the results are interpreted to mean that DHEA and pregnenolone, and not progesterone, are precursors of androgens in the follicle.


1984 ◽  
Vol 107 (3) ◽  
pp. 395-400 ◽  
Author(s):  
Itaru Kojima ◽  
Etsuro Ogata ◽  
Hiroshi Inano ◽  
Bun-ichi Tamaoki

Abstract. Incubation of 18-hydroxycorticosterone with the sonicated mitochondrial preparation of bovine adrenal glomerulosa tissue leads to the production of aldosterone, as measured by radioimmunoassay. The in vitro production of aldosterone from 18-hydroxycorticosterone requires both molecular oxygen and NADPH, and is inhibited by carbon monoxide. Cytochrome P-450 inhibitors such as metyrapone, SU 8000. SU 10603, SKF 525A, amphenone B and spironolactone decrease the biosynthesis of aldosterone from 18-hydroxycorticosterone. These results support the conclusion that the final reaction in aldosterone synthesis from 18-hydroxycorticosterone is catalyzed by an oxygenase, but not by 18-hydroxysteroid dehydrogenase. By the same preparation, the production of [3H]aldosterone but not [3H]18-hydroxycorticosterone from [1,2-3H ]corticosterone is decreased in a dose-dependent manner by addition of non-radioactive 18-hydroxycorticosterone.


2021 ◽  
Vol 11 (4) ◽  
pp. 1694
Author(s):  
Amna Komal Khan ◽  
Sidra Kousar ◽  
Duangjai Tungmunnithum ◽  
Christophe Hano ◽  
Bilal Haider Abbasi ◽  
...  

Flavonoids represent a popular class of industrially important bioactive compounds. They possess valuable health-benefiting and disease preventing properties, and therefore they are an important component of the pharmaceutical, nutraceutical, cosmetical and medicinal industries. Moreover, flavonoids possess significant antiallergic, antihepatotoxic, anti-inflammatory, antioxidant, antitumor, antiviral, and antibacterial as well as cardio-protective activities. Due to these properties, there is a rise in global demand for flavonoids, forming a significant part of the world market. However, obtaining flavonoids directly from plants has some limitations, such as low quantity, poor extraction, over-exploitation, time consuming process and loss of flora. Henceforth, there is a shift towards the in vitro production of flavonoids using the plant tissue culture technique to achieve better yields in less time. In order to achieve the productivity of flavonoids at an industrially competitive level, elicitation is a useful tool. The elicitation of in vitro cultures induces stressful conditions to plants, activates the plant defense system and enhances the accumulation of secondary metabolites in higher quantities. In this regard, nanoparticles (NPs) have emerged as novel and effective elicitors for enhancing the in vitro production of industrially important flavonoids. Different classes of NPs, including metallic NPs (silver and copper), metallic oxide NPs (copper oxide, iron oxide, zinc oxide, silicon dioxide) and carbon nanotubes, are widely reported as nano-elicitors of flavonoids discussed herein. Lastly, the mechanisms of NPs as well as knowledge gaps in the area of the nano-elicitation of flavonoids have been highlighted in this review.


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