Fermentation of liquid feed with lactic acid bacteria reduces dry matter losses, lysine breakdown, formation of biogenic amines and phytate-phosphorus

Effect of Fermented Rapeseed Meal in Diets for Piglets on Blood Biochemical Parameters and the Microbial Composition of the Feed and Faeces

The study assessed the influence of rapeseed meal (RSM) fermented using Bacillus subtilis 87Y on the feed microbiota, intestinal microbiota, blood biochemical parameters, and content of minerals in the blood plasma and faeces of piglets. Modulation of the microbial composition of feed containing fermented rapeseed meal (FRSM) and of the faeces of pigs consuming it was observed. There was a significant increase in the number of lactic acid bacteria (LAB) and a decrease in the total number of coliforms and Clostridium perfringens in the faeces of animals from the experimental groups. FRSM in the diet of piglets was shown to improve the mineral balance by increasing the levels of P, Ca, and Mg in the blood plasma and reducing their amount in the faeces. A beneficial effect on parameters of protein and lipid metabolism was also noted, resulting in an increase in the levels of total protein (TP) and albumins (ALB) and a reduction in triacylglycerols (TG) and low-density lipoprotein (LDL) cholesterol in the blood plasma of the piglets. The research results indicate that the presence of FRSM in the diet of weaners can be a preventive factor in intestinal dysbiosis and support the maintenance of homeostasis.

Microbial engineering for the production and application of phytases to the treatment of the toxic pollutants: A review

Phytases are a group of digestive enzymes which are commonly used as feed enzymes. These enzymes are used exogenously in the feeds of monogastric animals thereby it improves the digestibility of phosphorous and thus reduces the negative impact of inorganic P excretion on the environment. Even though these enzymes are widely distributed in many life forms, microorganisms are the most preferred and potential source of phytase. Despite the extensive availability of the phytase-producing microbial consortia, only a few microorganisms have been known to be exploited at industrial level. The high costs of the enzyme along with the incapability to survive high temperatures followed by the poor storage stability are noted to be the bottleneck in the commercialization of enzymes. For this reason, besides the conventional fermentation approaches, the applicability of cloning, expression studies and genetic engineering has been implemented for the past few years to accomplish the abovesaid benefits. The site-directed mutagenesis as well as knocking out have also validated their prominent role in microbe-based phytase production with enhanced levels. The present review provides detailed information on recent insights on the modification of phytases through heterologous expression and protein engineering to make thermostable and protease-resistant phytases.

Changes in the Microbial Community and Biogenic Amine Content in Rapeseed Meal during Fermentation with an Antimicrobial Combination of Lactic Acid Bacteria Strains

The aim of this study was to evaluate the microbial changes and biogenic amine (BA) formation in rapeseed meal (RP) during fermentation with a bacterial starter combination of Lactiplantibacillus plantarum-LUHS122 and -LUHS135, Lacticaseibacillus casei-LUHS210, Lentilactobacillus farraginis-LUHS206, Pediococcus acidilactici-LUHS29, and Liquorilactobacillus uvarum-LUHS245. Sampling was carried out after 12 h and 7, 14, 21, and 28 days of cultivation under conditions of constant changes to the substrate, with a change frequency of 12 h. The highest lactic acid bacteria (LAB) and yeast/mould counts were established in RP fermented for 14 days (8.29 and 4.34 log10 CFU/g, respectively); however, the lowest total enterobacteria count was found in RP fermented for 12 h (3.52 log10 CFU/g). Further metagenomic analysis showed that Lactobacillus spp. were the most prevalent species in fermented RP. The changes in microbial community in RP led to differences in BA formation. Putrescine and phenylethylamine were found in all fermented RP samples, while the contents of some other amines increased with prolonged fermentation. Finally, the use of combined fermentation could ensure Lactobacillus spp. domination; however, other parameters should be controlled due to the formation of undesirable compounds.