The Preparation Of Glycerol And Organic Selenium-enriched Probiotics

Energy metabolism disorder easily occurs because of the limited ability of ruminants directly absorbing and utilizing glucose and a series of drastic physiological changes, such as pregnancy, birth, during perinatal period. Glycerol is a glucogenic substance, and can be added to diet of ruminants. Glycerol can improve the metabolic regulation of blood and lactation performance, increase the concentration of glucose in blood, decrease the concentration of BHBA and NEFA in blood and urine ketones, and regulate energy balance. Selenium (Se) is an essential micro-mineral element for animals. It is a multi-purpose nutrient element, whose main function is antioxidant. The amount of reactive oxygen species in the body is over more than the normal level during the perinatal period. Se is involved in oxidative defense system. While supplementation with sodium selenite as inorganic Se in diet has been limited in some countries because inorganic form has disadvantages of lower incorporation, higher toxicity and more environment pollution compared with organic form.The aim of the present study was to transform glucose into glycerol, and inorganic Se into organic form by specific probiotics, and to produce the microbial feed additives which can exert triple effects of glycerol, organic Se and probiotics at the same time.Experiment1.The study was to compare four kinds of method of extraction of intracellular glycerol, and compare the yield of intracellular and extracellular glycerol in indifferent fermentation time. Four kinds of method were perchloric acid method, hydrochloric acid-heating method, distilled water-ultrasonic method, hydrochloric acid-ultrasound method. The method of glycerol detection was periodate oxidation-chromotropic acid method. The result showed distilled water-ultrasonic method was the best one. The yield of extracellular glycerol was far higher than that of extracellular glycerol.Experiment2.The study was to research the effect of all culture conditions on the yield of glycerol. Culture conditions were optimized to ascertain industrial culture conditions to produce the compound probiotics rich in glycerin and organic Se through single factor experiments and orthogonal test. It was concluded that the medium for highest yield of glycerol was sodium chloride hypertonic medium, with2g·L-1corn syrup powder,6.5%inoculum sizes, the initial pH was5, culture temperature was33℃, and that the culture time were120h. The highest yield of glycerol was60.94g·L-1. The yield of glycerol decreased significantly after adding Streptococcus thermophilus or inorganic Se. The result showed that the glycerol fermentation test and the organic selenium transformation test were done separately.Experiment3.The purpose is to research the process of producing the compound probiotics rich in glycerol and organic Se and its stabilization in storage. The difference on the yield of glycerol, the growth of probiotic between different culture apparatus: fermentation tank and conical flask under certain conditions was researched. When mixed the absorbent with the compound probiotics rich in glycerin and organic Se, the product was processed after drying. Varies on yield of glycerol, growth of probiotic and organic Se conversion were estimated when the product was stored. The result showed that there is no marked difference on two indexes when culture apparatus changed between fermentation tank and conical flask. The ferment of producing glycerol and the centrifugal sedimentation of ferment of the organic selenium transformation test were fixed with corn powder, and dried. The glycerol content was82.4g/Kg, organic Se concentration reached8.39μg·g-1, and the population of three probiotics were9.38×108cfu·g-1、7.69×108cfu·g-1、7.45x109cfu·g-1. The content of glycerol and organic selenium remained unchanged in storage. Population of Ck and Cu reduced significantly when storage duration was up to one month. Population of St reduced significantly when duration reached three months.