scholarly journals Effects of Lacto-Fermented Agricultural By-Products as a Natural Disinfectant against Post-Harvest Diseases of Mango (Mangifera indica L.)

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 285
Author(s):  
Fernando H. Ranjith ◽  
Belal J. Muhialdin ◽  
Noor L. Yusof ◽  
Nameer K. Mohammed ◽  
Muhammad H. Miskandar ◽  
...  

Background: the antagonism activity of lactic acid bacteria metabolites has the potential to prevent fungal growth on mango. Methods: the potential of developing natural disinfectant while using watermelon rinds (WR), pineapple (PP), orange peels (OP), palm kernel cake (PKC), and rice bran (RB), via lacto-fermentation was investigated. The obtained lactic acid bacteria (LAB) metabolites were then employed and the in vitro antifungal activity toward five spoilage fungi of mango was tested through liquid and solid systems. Besides, the effect of the produced disinfectant on the fungal growth inhibition and quality of mango was investigated. Results: the strains Lactobacillus plantarum ATCC8014 and Lactobacillus fermentum ATCC9338 growing in the substrates PKC and PP exhibited significantly higher in vitro antifungal activity against Colletotrichum gloeosporioides and Botryodiplodia theobromae as compared to other tested LAB strains and substrates. The in-situ results demonstrated that mango samples that were treated with the disinfectant produced from PKC fermented with L. plantarum and L. fermentum had the lowest disease incidence and disease severity index after 16 days shelf life, as well as the lowest conidial concentration. Furthermore, PKC that was fermented by L. fermentum highly maintained the quality of the mango. Conclusions: lactic acid fermentation of PKC by L. fermentum demonstrated a high potential for use as a natural disinfectant to control C. gloeosporioides and B. theobromae on mango.

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.


Author(s):  
Mercy Aboh ◽  
Ngozi Amaeze ◽  
Ijeoma Ikeji ◽  
Peters Oladosu

Increasing consumer demand for natural products have renewed food industry attention in bio preservation. Lactic acid bacteria are of particular interest as effective alternative to chemical preservation because of their food grade status. This work explores the effect of antifungal compounds produced by isolates of Lactobacillus sp on some selected pathogenic fungi growth. Samples of diary and fermented products were purchased from commercial vendors within the Federal Capital Territory (FCT) and screened for the presence of Lactobacillus sp. The Lactobacillus sp isolated were screened for antifungal activity against Aspergillus fumigatus, Candida albicans and Trichophyton rubrum using a dual culture assay. Strains with antifungal activity were identified and the fungal inhibitory activity was further evaluated. The effect of abiotic factors on the antifungal activity was evaluated by overlay assay under different temperature and pH. Majority of the identified isolates belonged to the genus Lactobacillus. Lactobacillus sp. produced antifungal compounds under different temperatures (25ºC, 30ºC and 37ºC). The antifungal compounds produced by Lactobacillus strains showed greater inhibitory activity on Aspergillus fumigatus. At 30ºC the percentage zones of inhibition range were 44.4%- 60.4%. All isolates showed stronger antifungal activity when grown at pH 4.0 and 5.0. At a pH 2.0 there was a total inhibition of fungal growth however, there was no inhibition of fungal growth at the pH 7.0. Lactic acid bacteria can be employed as effective alternative to chemical preservatives in food. Temperature and pH of the culture medium could influence the production of antifungal compounds by lactic acid bacteria.


2020 ◽  
Vol 15 (6) ◽  
pp. 648-655
Author(s):  
Gabriel O. de Azambuja ◽  
Laura Svetaz ◽  
Itamar L. Gonçalves ◽  
Patricia F. Corbelini ◽  
Gilsane L. von Poser ◽  
...  

Background: Since the Monastrol discovery in 1999 as the first inhibitor of Eg5, functionalized dihydropyrimidinones/thiones (DHPMs) have emerged as prototypes for drug design in different targets. The present work aimed to evaluate the antifungal activity of a chemical library of DHPMs. Methods: The compounds were obtained employing Biginelli reaction. Their antifungal activities were assessed against C. neoformans and C. albicans. Results: The compounds 1-i and 1-k inhibited moderately the fungal growth of C. neoformans, with compound 2-k presenting MIC80 values of 62.5-125 µg·mL-1. Considering activity against C. albicans, the compounds 1-i and 1-n present an MIC50 value of 125-250 µg·mL-1. Conclusion: The changes performed in DHPM scaffold appear to be valuable for generating compounds with potential antifungal effect.


2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Chae Eun Song ◽  
Han Hyo Shim ◽  
Palaniselvam Kuppusamy ◽  
Young-IL Jeong ◽  
Kyung Dong Lee

The objective of this study was to investigate alginate microencapsulated lactic acid bacteria (LAB) fermentation quality of radish kimchi sample and its potential survivability in different acidic and alkaline environments. Initially, we isolated 45 LAB strains. One of them showed fast growth pattern with potential probiotic and antifungal activities against Aspergillus flavus with a zone of inhibition calculated with 10, 8, 4mm for the 4th, 5th, and 6th day, respectively. Therefore, this strain (KCC-42) was chosen for microencapsulation with alginate biopolymer. It showed potential survivability in in-vitro simulated gastrointestinal fluid and radish kimchi fermentation medium. The survival rate of this free and encapsulated LAB KCC-42 was 6.85 × 105 and 7.48× 105 CFU/ml, respectively; the viability count was significantly higher than nonencapsulated LAB in simulated gastrointestinal juices (acid, bile, and pancreatin) and under radish kimchi fermentation environment. Kimchi sample added with this encapsulated LAB showed increased production of organic acids compared to nonencapsulated LAB sample. Also, the organic acids such as lactic acid, acetic acid, propionic acid, and succinic acid production in fermented kimchi were measured 59mM, 26mM, 14mM, and 0.6mM of g/DW, respectively. The production of metabolites such as lactic acid, acetic acid, and succinic acid and the bacteria population was high in microencapsulated LAB samples compared with free bacteria added kimchi sample. Results of this study indicate that microencapsulated LAB KCC-42 might be a useful strategy to develop products for food and healthcare industries.


2021 ◽  
Vol 72 (1) ◽  
pp. e400
Author(s):  
F. Panebianco ◽  
A. Caridi

The anti-mold activity of 397 strains of lactic acid bacteria was evaluated using both the spot method in Petri plates and coculture in liquid medium. The study led to the selection of 34 strains isolated from table olives or olive brines, 15 strains from dairy products, and 10 strains from sourdoughs, all able to inhibit a strain of Penicillium crustosum and/or a strain of Aspergillus section Nidulantes, prevailing in two Calabrian olive brines. Seven representative strains were identified as Lactobacillus pentosus (four strains) and Lactobacillus sanfranciscensis (three strains) and are currently under testing for their antifungal activity during table olive fermentation. This research constitutes an initial contribution to the control of fungal growth and mycotoxin accumulation during table olive fermentation. The selected strains could be used as adjunct cultures in table olive fermentation, allowing for the biological control of table olive safety.


2020 ◽  
Vol 18 (1) ◽  
pp. 103-112
Author(s):  
R. A. OLOYEDE ◽  
A. A. ILUPEJU ◽  
O. O. OYELAKIN ◽  
W. R. AJIJOLA

Fusarium wilt is one of the important diseases of cucumber and causes economic loss to farmers. The present study was undertaken to evaluate the potential of rhizosphere lactic acid bacteria as biocontrol agents of Fusarium wilt of cucumber. Lactic acid bacteria (LAB) were isolated and identified from the rhizosphere of five medicinal plants. The in-vitro antagonistic activity of LAB strains on F. oxysporum f.sp. cucumerinum was evaluated by dual culture method. The screen house experiment was then conducted to assess the effect of antagonistic LAB isolates on Fusarium wilt disease incidence in cucumber plants. The antagonistic LAB strains were further characterized using 16S rRNA gene sequencing technique. The total LAB counts of rhizospheric soil samples ranged from 7.0×105 cfu/g to 15.0×105 cfu/g. The LAB isolates were identified as strains of Lactobacillus acidophilus (21.4%), L. plantarum (35.7%), L. fermentum (28.6%), L. alimentarius (7.1%) and L. brevis (7.1%). Treatment of cucumber seeds with antagonistic LAB strains significantly reduced Fusarium wilt of cucumber incidence from 95% to 48%. Lactobacillus fermentum isolated from the rhizosphere of A. indica exhibited strong disease suppression (49.5%). The study therefore revealed that the rhizospheric-LAB could be applied to reduce the manifestation of Fusarium wilt in cucumber.    


1998 ◽  
Vol 44 (1) ◽  
pp. 74-79 ◽  
Author(s):  
Elias K Manavathu ◽  
S C Vashishtha ◽  
George J Alangaden ◽  
Jonathan R Dimmock

Four Mannich bases of some conjugated styryl ketones IIa-IId were examined for antifungal activity. These compounds were designed as thiol-alkylators and had two centers for attack by cellular thiols. The most potent compounds IIa and IIb possessed hydrophobic, electron-attracting substituents in the aryl rings and in general had minimum inhibitory concentration (MIC) values of 0.2-25 μM against a variety of fungi. None of the four compounds inhibited the growth of a number of bacteria (MIC > 100 μM). The minimum fungicidal concentration (MFC) values for IIa and IIb were generally either similar or twofold higher than the MIC figures for fungi. Compound IIa demonstrated rapid, concentration-dependent inhibition of the growth of Candida albicans B311. The toxicity of IIa to normal human cells was much lower than the concentrations of this compound required to inhibit fungal growth. In summary, this study of four prototypic molecules has revealed that this class of compounds may have potential for further development as candidate antifungal agents.Key words: antifungal, styryl ketones, Candida albicans, Aspergillus fumigatus, susceptibility test.


2020 ◽  
Vol 9 (1) ◽  
pp. 78
Author(s):  
Sabrina Strafella ◽  
David J. Simpson ◽  
Mohammad Yaghoubi Khanghahi ◽  
Maria De Angelis ◽  
Michael Gänzle ◽  
...  

This study aimed to isolate lactic acid bacteria (LAB) from wheat rhizosphere, to characterize their in vitro plant growth promoting activities and to differentiate plant-associated LAB from those associated with foods or human disease through comparative genomic analysis. Lactococcus lactis subsp. lactis and Enterococcus faecium were isolated using de Man-Rogosa-Sharpe (MRS) and Glucose Yeast Peptone (GYP) as enrichment culture media. Comparative genomic analyses showed that plant-associated LAB strains were enriched in genes coding for bacteriocin production when compared to strains from other ecosystems. Isolates of L. lactis and E. faecium did not produce physiologically relevant concentrations of the phyto-hormone indolacetic acid. All isolates solubilized high amount of phosphate and 12 of 16 strains solubilized potassium. E. faecium LB5, L. lactis LB6, LB7, and LB9 inhibited the plant pathogenic Fusarium graminearum to the same extent as two strains of Bacillus sp. However, the antifungal activity of the abovementioned LAB strains depended on the medium of cultivation and a low pH while antifungal activity of Bacillus spp. was independent of the growth medium and likely relates to antifungal lipopeptides. This study showed the potential of rhizospheric LAB for future application as biofertilizers in agriculture.


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