Stability of Dry and Liquid Metschnikowia pulcherrima Formulations for Biocontrol Applications against Apple Postharvest Diseases

The yeast Metschnikowia pulcherrima is frequently isolated from environmental samples and has often been reported to exhibit strong antagonistic activity against plant pathogens. In order to assess the potential of this species for its development into a plant protection product, the survival during formulation and storage were quantified and field efficacy was assessed over a period of five years. Freeze dried and liquid M. pulcherrima formulations (i.e., with skim milk powder (SMP), sucrose, glycerol, xanthan, without additives) were prepared and the number of viable cells was quantified during storage at different temperatures. Field trials against apple postharvest diseases (Neofabreae) were performed with different dry formulations. M. pulcherrima proved exceptionally stable for many months and even years. Five years of field trials with the yeast revealed variable effects, but reduced Neofabreae infections of stored apples were observed in some years. M. pulcherrima applications after prior fungicide treatments repeatedly showed an additive effect as compared to the fungicide treatments alone. In summary, M. pulcherrima exhibited highly advantageous storage properties and encouraging activity against apple postharvest rots. Further studies to identify the factors responsible for antagonistic activity in the field and survival during storage are expected to lay the foundation for the future development of a plant protection product.

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VIABILITY OF LACTOBACILLUS acidophilus AND SYNERESIS OF PROBIOTIC YOGHURT PRODUCED FROM RECONSTITUTED SKIM AND WHOLE MILK POWDER DURING 35 DAYS REFRIGERATED STORAGE AT 4±2 oC

Bacterial Empire ◽

10.36547/be.2019.2.2.54-57 ◽

2019 ◽

Vol 2 (2) ◽

pp. 54

Author(s):

Obhioze Augustine Akpoka ◽

T. E Obi

Keyword(s):

Lactobacillus Acidophilus ◽

Starter Culture ◽

Milk Powder ◽

Skim Milk ◽

Streptococcus Thermophilus ◽

Lactobacillus Bulgaricus ◽

Probiotic Bacteria ◽

Whole Milk ◽

Freeze Dried ◽

Whole Milk Powder

Currently, the food industry wants to expand the range of probiotic yogurts but each probiotic bacteria offers different and specific health benefits. This study examined the viable counts of Lactobacillus acidophilus and percentage syneresis of probiotic yoghurt produced from reconstituted skim and whole milk powder stored for 35 days at 4±2 oC. Skim milk probiotic yoghurt (SMPY) and Whole milk probiotic yoghurt (WMPY) were produced by reconstituting dry milk powder (130 g/900 ml w/v), which was pasteurized at 85 oC for 15 mins, cooled to 43 oC and inoculated with freeze dried probiotic yoghurt mixed starter culture containing Streptococcus thermophilus (ST), Lactobacillus bulgaricus (LB) and Lactobacillus acidophilus (LA). The yoghurt samples were analyzed for viability of ST, LB, LA and also syneresis. During storage, the viable counts of ST in SMPY decreased from 5.43x108 to 5.18x106 cfu/ml, LB (2.47x108 to 8.10x105 cfu/ml) and LA (1.83x108 to 5.78x105 cfu/ml). Similarly, the viable counts of ST in WMPY decreased significantly from 5.40x108 to 5.15x106 cfu/ml, LB (2.43x108 to 7.82x105 cfu/ml) and LA (1.80x108 to 5.84x105 cfu/ml). Although the mean viable counts of the LA decreased during storage, both SMPY and WMPY still contained an average of 1.48x106 cfu/ml of probiotic cells up to 28 days of storage, which is above the “therapeutic minimum” of 106 cfu/ml. The percentage syneresis of SMPY and WMPY increased significantly during the 35 days of storage, from 24.4-32.0 % and 24.8-32.7 % respectively. There was a positive correlation between storage time and syneresis thus affecting the texture. In conclusion, yoghurt made from either skim or whole milk powder can be used as an adequate carrier of LA (probiotic bacteria) up to a period of 28 days at 4±2 oC and a stabilizer should be used to reduce the separation of whey and thus maintain the texture.

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Evaluation of Native Wine Yeast as Biocontrol Agents Against Fungal Pathogens Related to Postharvest Diseases

10.20944/preprints201909.0113.v1 ◽

2019 ◽

Author(s):

Paula Reyes-Bravo ◽

Andrea Acuña-Fontecilla ◽

Ines Marlene Rosales ◽

Liliana Godoy

Keyword(s):

Biological Control ◽

Antimicrobial Agents ◽

Plant Protection ◽

Antagonistic Activity ◽

Penicillium Expansum ◽

In Vitro Assays ◽

Postharvest Diseases ◽

Antagonistic Microorganisms ◽

Chemical Products ◽

The Impact

Changes in consumer expectations have led to increasing demand for novel plant protection strategies, in order to reduce the application of chemical products, reduce the occurrence of new pests and the impact that all these actions generate in the environment. In recent years there have been numerous investigations related to biological control and the use of microorganisms as new control strategies. As part of integrated disease management, antagonistic microorganisms have been investigated lately and presented great interest. Such microorganisms can be applied in conventional and in organic farming as biological control agents (BCA). Many of these microorganisms are present in the microbial ecology generating interactive associations between surrounding microorganisms. For these reasons, it has become necessary to search new natural antimicrobial agents as alternatives to synthetic and chemical products. It has been discovered that there are microorganisms, particularly yeasts, that have antagonistic activity and different mechanisms of action, indicating that they could be interesting candidates for the development of BCA. Here, we evaluate the antagonist effect of four endophytic yeast, Cryptococcus antarcticus, Aureobasidium pullulans, Cryptococcus terrestris and Cryptococcus oeirensis over the growth of Botrytis cinerea, Monilinia laxa, Penicillium expansum and Geotrichum candidum in in vitro assays (inhibition zone diameter assay and confrontation assay).The results revealed that the four yeast strains evaluated showed antagonistic activity against the phytopathogens tested, suggesting that these yeasts produce compounds capable of inhibiting the growth of fungi and, depending on the assay, the evaluated antagonist-yeasts have differential biocontrolling-effect against the postharvest pathogens tested.

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A technique for evaluating reconstitution properties of milk powders

Journal of Dairy Research ◽

10.1017/s0022029900014461 ◽

1973 ◽

Vol 40 (2) ◽

pp. 135-147

Author(s):

T. C. Wyeth ◽

G. C. Cheeseman

Keyword(s):

Quantitative Data ◽

Milk Powder ◽

Skim Milk ◽

The Other ◽

Reproducible Technique ◽

Freeze Dried ◽

The Ideal

SummaryAn accurate and reproducible technique involving a continuous aqueous elution from a bed of dried-milk powder was developed to evaluate reconstitution characteristics. Quantitative data for the determination of reconstitution behaviour were obtained by analysis of the eluate for protein, lactose and Ca constituents. A reconstitution coefficient (P) was derived from the formula (W1+ΣWi)/T, where W1 was the amount reconstituted in the first eluate fraction, ΣWi the total amount reconstituted in 8 fractions, and T the time taken for 1/3 of the constituent to be reconstituted. Values obtained for P were thus related to the reconstitution properties and could be used to grade the powders. A freeze-dried skim-milk gave the ideal reconstitution behaviour with W1 values in the range 42·0–44·2, ΣWi values in the range 93·6–101·3, T values in the range 3·0–3·3 and reconstitution coefficients in the range 41·1–46·3 for the 3 constituents. All the other preparations tested gave lower values for W1 and P, although some gave ΣWi values in the same range, whilst all T values were higher than those for the freeze-dried sample.

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Identification and Effects of Skim Milk-Derived Bioactive Antihypertensive Peptides

Biologics ◽

10.3390/biologics2010001 ◽

2021 ◽

Vol 2 (1) ◽

pp. 1-14

Author(s):

Fatah B. Ahtesh ◽

Lily Stojanovska ◽

Vijay Mishra ◽

Osaana Donkor ◽

Jack Feehan ◽

...

Keyword(s):

Blood Pressure ◽

Bioactive Peptides ◽

Milk Powder ◽

Skim Milk ◽

Fermented Milk ◽

Skim Milk Powder ◽

Angiotensin Converting Enzyme Inhibition ◽

Blood Pressure Lowering Effect ◽

Spontaneously Hypertensive ◽

Freeze Dried

Bioactive peptides are generated during milk fermentation or enzymatic hydrolysis. Lactobacillus (L) helveticus is commonly used to produce some types of fermented milk products. Fermented milk derived bioactive peptides are known to be beneficial in human health. Anti-hypertensive peptides play a dual role in the regulation of hypertension through the production of the vasoconstrictor angiotensin II and its inactivation of the vasodilator bradykinin. MALDI MS/MS, nano-LC/MS/MS and RP-HPLC were used to isolate peptides showing angiotensin converting enzyme inhibition (ACE-I) from 12% fermented skim milk using a combination of L. helveticus and Flavourzyme®. The fermentation procedure facilitated the identification of 133 anti-hypertensive peptides and 75% short chain amino acids, and the three with the highest ACE-I activity reduced blood pressure in a rat model of hypertension. The freeze- dried extract was supplemented in rodent chow. In this study 14-week-old male spontaneously hypertensive rats were fed for 10 weeks with the identified peptides added to chow and compared to controls supplemented with skim milk powder. Blood pressure (BP) decreased significantly (p < 0.05) from 6 to 10 weeks of FS groups (120/65 mmHg) compared with the NFS control groups, where the BP increased significantly (220/150 mmHg) (p < 0.05). The F6 fraction provided bioactive peptides with stronger antihypertensive properties than other fractions. Skim milk fermented by L. helveticus and Flavourzyme® generates several bioactive peptides which have a blood pressure lowering effect in hypertensive disease.

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EFFECT OF PHYTOP 8.67 SPECIMEN ON THE CARROT

Bulletin of NSAU (Novosibirsk State Agrarian University) ◽

10.31677/2072-6724-2020-55-2-69-75 ◽

2020 ◽

pp. 69-75

Author(s):

V. P. Tsvetkova ◽

V. S. Maslennikova ◽

V. A. Nesterenko

Keyword(s):

Crop Yields ◽

Plant Protection ◽

Vegetation Period ◽

Field Trials ◽

Production Quality ◽

Antagonistic Activity ◽

Genus Bacillus ◽

Pests And Diseases ◽

Brown Leaf ◽

Alternaria Dauci

The UN Food Agency announced 2020 as International Year for Plant Protection. About 40% of crop yields losses are caused by pests and diseases. Due to this, millions of people suffer from hunger. Therefore, there is a need to seek for and select environmentally friendly and highly effective products that will increase yields and the production quality. In 2017-2018, in the Novosibirsk Region, it was shown in field trials and production experiments that the biopreparation Phytop 8.67 based on the bacteria of the genus Bacillus has antagonistic activity in relation to carrot alternativeariosis (the causative agent is Alternaria dauci carrots, reduces the plants prevalence during the vegetation period, and also has a growth stimulating effect. The prevalence of brown leaf spotting decreased by 4.8 times, and the biological effect of Phytop 8.67 in two years with respect to the disease progress was 63.2 (after 10 weeks) and 78.4% (after 12 weeks). In the experimental variants, the plants were statistically more reliable than the control ones and were more foliated on all the dates of accounting. Application of biospecimen increased 1 root crop weight by 1,7 times in the control variant, in finedelivery experiment and by 1,4 times - in industrial one. Due to this, the authors recommend applying Phytop 8.67 specimen as a fungicide, a growth stimulator in order to increase carrot productivity.

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Genome, transcriptome and secretome analyses of the antagonistic, yeast-like fungus Aureobasidium pullulans to identify potential biocontrol genes

Microbial Cell ◽

10.15698/mic2021.08.757 ◽

2021 ◽

Vol 8 (8) ◽

pp. 184-202

Author(s):

Maria Paula Rueda-Mejia ◽

Lukas Nägeli ◽

Stefanie Lutz ◽

Richard D. Hayes ◽

Adithi R. Varadarajan ◽

...

Keyword(s):

Aureobasidium Pullulans ◽

Plant Pathogens ◽

Target Genes ◽

De Novo ◽

Genome Mining ◽

Antagonistic Activity ◽

Ecological Niches ◽

Postharvest Diseases ◽

Sequential Approach ◽

Genes Encoding

Aureobasidium pullulans is an extremotolerant, cosmopolitan yeast-like fungus that successfully colonises vastly different ecological niches. The species is widely used in biotechnology and successfully applied as a commercial biocontrol agent against postharvest diseases and fireblight. However, the exact mechanisms that are responsible for its antagonistic activity against diverse plant pathogens are not known at the molecular level. Thus, it is difficult to optimise and improve the biocontrol applications of this species. As a foundation for elucidating biocontrol mechanisms, we have de novo assembled a high-quality reference genome of a strongly antagonistic A. pullulans strain, performed dual RNA-seq experiments, and analysed proteins secreted during the interaction with the plant pathogen Fusarium oxysporum. Based on the genome annotation, potential biocontrol genes were predicted to encode secreted hydrolases or to be part of secondary metabolite clusters (e.g., NRPS-like, NRPS, T1PKS, terpene, and β-lactone clusters). Transcriptome and secretome analyses defined a subset of 79 A. pullulans genes (among the 10,925 annotated genes) that were transcriptionally upregulated or exclusively detected at the protein level during the competition with F. oxysporum. These potential biocontrol genes comprised predicted secreted hydrolases such as glycosylases, esterases, and proteases, as well as genes encoding enzymes, which are predicted to be involved in the synthesis of secondary metabolites. This study highlights the value of a sequential approach starting with genome mining and consecutive transcriptome and secretome analyses in order to identify a limited number of potential target genes for detailed, functional analyses.

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The Effectiveness of Tobacco Oil Fungicidal Preparation Towards Powdery Mildew of Wheat (Blumeria graminis f. sp. tritici)

The Open Agriculture Journal ◽

10.2174/1874331501610010001 ◽

2016 ◽

Vol 10 (1) ◽

pp. 1-6

Author(s):

Donyo Ganchev ◽

Neno Nenov

Keyword(s):

Powdery Mildew ◽

Future Development ◽

Organic Agriculture ◽

Plant Protection ◽

Field Trials ◽

Blumeria Graminis ◽

Plant Protection Product ◽

Fungicidal Effect ◽

Pesticide Formulation ◽

The Future

The pesticide formulation prepared as "ready to be used plant protection product" on the basis of tobacco oil was created and tested in two years field trials against powdery mildew of wheat (Blumeria graminis f. sp. tritici). The results showed strong fungicidal effect without any phytotoxic activities (chemotherapeutic coefficient = 10) onto treated plants. This indicates the future development of this pesticide formulation as effective, natural friendly and cheap product for plant protection, which can be used both in commercial and organic agriculture.

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An Antagonism of Isolates of Root-Associated Bacteria Consortia Habituating in Banana Rhizosphere

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.879.83 ◽

2018 ◽

Vol 879 ◽

pp. 83-88 ◽

Cited By ~ 1

Author(s):

Duongruitai Nicomrat ◽

Pattarika Soongsombat ◽

Nednapa Suenonmueng ◽

Ninlawan Marjang

Keyword(s):

Bacterial Communities ◽

Fungal Pathogen ◽

Plant Pathogens ◽

Plant Protection ◽

Root Exudation ◽

Antagonistic Activity ◽

Plant Roots ◽

Associated Bacteria ◽

Plant Microbe Interaction ◽

Bioactive Agents

Microbial diversity based on plant-microbe interaction as well as most fungal diseases which are such multipathogen complexes have been long researched. Most beneficial microbes promote the growth of the plant but inhibit the growth of plant pathogen as biocontrol agents and are reported for their establishment being microbial communities associated to the plant roots. We were interested in understanding the antagonistic activity of root-associated bacterial communities in the rhizospheres. In this experiment, common bacteria associated with banana root exudation that were cultivated and isolated harbored specific antagonistic to common pathogen. In the experiments, the root (rhizosphere), and interior of the pseudostem (endosphere) samples were high CFU counts in the extracted endosphere than in rhizosphere of banana roots (6-8 and 4-5 CFU/ g, respectively). Antibacterial activity as bioactive agents were detected from these microbes as antagonis activity against plant pathogens that wereBacillus indicus, Pseudomonas palleroniana, Penicilliumspp andFusarium oxysporum. both mixed consortia could control Fusarium, fungal pathogen in banana. From this study, the isolates of indigenous bacteria obtained from banana rhizosphere can be potential for agricultural uses as further as disease-suppressive microorganisms provides promising perspectives for sustainable plant protection.

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Survival in foods of Staphylococcus aureus grown under optimal and stressed conditions and the effect of some food preservatives

Canadian Journal of Microbiology ◽

10.1139/m83-049 ◽

1983 ◽

Vol 29 (3) ◽

pp. 297-302 ◽

Cited By ~ 7

Author(s):

A. A. El-Banna ◽

A. Hurst

Keyword(s):

Staphylococcus Aureus ◽

Milk Powder ◽

Skim Milk ◽

Skim Milk Powder ◽

Potassium Sorbate ◽

C Cells ◽

Green Beans ◽

Food Preservatives ◽

Freeze Dried ◽

Peptone Medium

Staphylococcus aureus was grown in a rich peptone medium which became alkaline with continued incubation. Cells were grown at 37 °C and in the same medium containing 1 M NaCl at 46 °C, a temperature at which this organism can grow only when protected by NaCl. Cells of these cultures are hereafter called 37 °C-cells and 46 °C-cells, respectively. The 37 °C-cells harvested when the pH was 7.1 to 7.7 had decimal reduction times (D60-value) of 1.8 to 3.1 min in 50 mM pH 7.2 Tris buffer. The D60 value of 46 °C-cells tested in the same way, harvested from cultures at pH 6.6 to 7.6, ranged from 5.3 to a maximum of 12.8 min. In milk, green beans, peas, or beef slurry, the D60- value of 46 °C-cells was about four times higher than that of 37 °C-cells. Length of survival after freeze-drying in skim-milk powder exposed to air was longest for the cells with the highest D-value. In freeze-dried peas and media acidified with acetic and lactic acids, 46 °C-cells survived longer than 37 °C-cells. However, the sensitivity of the two kinds of cells to potassium sorbate, sodium benzoate, and sodium propionate was essentially the same, but the 46 °C-cells were more resistant to butylated hydroxyanisole and sodium nitrite.

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