Cytosporone B as a Biological Preservative: Purification, Fungicidal Activity and Mechanism of Action against Geotrichum citri-aurantii

To prevent citrus decay caused by Geotrichum citri-aurantii, 12 natural products were isolated from two endophytic fungi, in which cytosporone B was shown to have excellent bioactivity for control of G. citri-aurantii with median effect concentration (EC50) of 26.11 μg/mL and minimum inhibitory concentration (MIC) of 105 μg/mL, and also significantly reduced the decay of sugar orange during the in vivo trials. In addition, cytosporone B could alter the morphology of G. citri-aurantii by causing distortion of the mycelia and loss of membrane integrity. Differentially expressed genes (DEGs) between cytosporone B-treated and -untreated samples were revealed by Illumina sequencing, including 3540 unigenes. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses showed that most DEGs were related to metabolic production and cell membrane. These findings suggest cytosporone B is a promising biological preservative to control citrus decay and reveal the action mechanism of cytosporone B in relation to the destruction of the fungal cell membrane at both morphological and molecular levels.

INFLUENCE OF STATE HAY WITH BIOLOGICAL CONSERVATIVES ON MILK AND CHEESE QUALITY

The purpose of the study is to improve the property of eastern galega haylage by using verdant grass preservative applicator and biologies. Iit was established that the eastern galega verdant grass, because of the low sugar con-tent, is not good for state hay purchasing due to the of the obtained results. The biological preservative applicators use for state hay purchasing significantly improves the quality of feed. The preservatives use for verdant grass al-lowed to increase the active acidity of the finished feed in the range between 6.3 to 11.2%, the content of lactic acid – 0.51-0.84 per cent and to reduce the content of acetic acid by 0.19 and 0.27%, respectively. The proportion of lactic acid in the total volume of organic acids was increased by 13.03-16.88%.The nutritional value of haylage with bio-logical preservative applicants increased due to augment of the dry content by 1.7-3.2%, EKE – by 4.4-11.1%, crude protein – by 4.3-10.1%, digestible protein – by 7.4-14.7%.The coefficient of digestibility in the diet of dry con-tent increased by 1.14-3.19%, crude protein – by 2.14-3.62%, crude fat – by 1.64-4.09%, crude fiber – by 1.74-3.87%, BEV – by 2.05-4.13%, which is very important for animal feeding. The use of haylage with a preservative in the diet of cows from experimental groups increased the fat content in milk by 0.03-0.08%, protein – by 0.04-0.10%, and casein contained – by 0.07-0.18%. Rennet additive apply helps milk to coagulate faster by 2.3-4.5 min (6.6-12.8%), and decrease losses of dry content with serum by 1.5-3.0%. The dry content mass in the experimental samples of cheese increased by 2.8-4.7%, fat – by 1.6-2.7%, protein – by 0.7-1.6%, the degree of cheese maturity improved. The «Milostan and Loktantra + zeolite» preservatives provide better properties for products produced.

Productivity of lactating cows fed on a diet of haylage from a vetch pea-oat mixture with the introduction of new biological preservative

The effect of a new biological preservative representing a mix of lyophilized Lactobacillus plantarum VKPM V-4173, Lactococcus lactis subsp. lactis VKPM V-2092 and Propionibacterium acidipropionici VKPMV-5723 strains (40 : 40 : 20) on the quality of haylage prepared from a mix of vetch, oats, and pea has been studied. The total bacteria content in the preservative was 1·1011 CFU/g. Five different variants of conservation of alfalfa haylage prepared at the budding stage were evaluated under laboratory conditions. The variants included a self-conserved control and the preservative at two different dosages (3 and 6 g/ton) with and without the addition of cellulolytic enzymes. The best results were observed in the case of both the enzyme-free and the enzyme-containing preservative at the dosage equal to 6 g/ton. These variants provided the maximum protein content in the haylage (94.3% and 94.5% of the initial content, respectively) and a high content of lactic acid (62.9% and 65.4% of the total acid content, respectively) and also good organoleptic characteristics. The determined optimum biopreservative dosage was tested under industrial conditions using 750 tons of vetch-oats-pea haylage. The use of the biopreservative provided a high-quality haylage of high nutritive value. Industrial evaluation of the effect on the productivity of milk cattle (n = 15) of the addition of the biopreservative to the haylage showed that the maximum average daily yield of milk with basic fat content (3.4%) was obtained from cows of the experimental group whose ration included haylage prepared with the use of the studied preservative. This yield came to32.7 kg , which exceeded the yield for the control group (fed on self-conserved haylage) by 7.0%. Three months feeding of cows with the haylage prepared with the use of the new preservative brought a significant saving of money (4,862 rubles per a head at the prices of 2015–2016).