1. The widespread use of antibiotics is a global problem, especially in countries where the breeding industry is relatively underdeveloped. Due to the harsh breeding environment and frequent outbreaks of epidemic diseases, the problem is even more serious. According to reports: China produces approximately 210,000 tons of antibiotic raw materials each year, of which 46.1% (97,000 tons) is used in animal husbandry, mainly for the growth of animals and the prevention of diseases. The abuse of antibiotics has a negative impact on public health, food Safety and environmental pollution have a huge impact, and reducing the use of antibiotics in the livestock and poultry breeding process has become an urgent problem that the livestock and poultry breeding industry faces today.
In view of this, CN201610771718.X proposes a Saccharomyces cerevisiae culture and its preparation method and application to reduce or replace the use of antibiotics and reduce antibiotic residues in livestock and poultry products. Based on the above-mentioned purpose, the preparation method of Baker’s Yeast culture provided by the invention comprises the following steps:
1) Saccharomyces cerevisiae is carried out seed culture, obtains Baker’s Yeast seed culture;
2) Inoculating the Saccharomyces cerevisiae seed culture into a liquid medium for aerobic fermentation to obtain a Baker’s Yeast liquid culture;
3) Inoculate the liquid culture of Baker’s Yeast into a solid medium for anaerobic fermentation. After the fermentation, the yeast is subjected to wall-breaking treatment, and then the solid culture of Saccharomyces cerevisiae after the wall-breaking treatment is dried to obtain the brewer’s yeast yeast culture.
2. There are many kinds of organic pollutants in water, and it is difficult to determine the quantitative values of various components separately. Therefore, in the process of water quality evaluation, biochemical oxygen demand (biochemical oxygen demand, BOD) is an important parameter, which refers to a certain volume The amount of dissolved oxygen consumed by the oxidation of organic matter in the water body under the action of microorganisms, the unit is mg/L. It can be seen from the above definition that BOD represents the degree of pollution of organic pollutants in water.
Since BOD can indirectly represent the content of microbial oxidized organic matter, BOD has become one of the most widely used monitoring indicators in the field of water pollution control. CN200910090646.2 discloses a method for quickly measuring BOD using Saccharomyces cerevisiae as a biorecognition element. The rapid determination of BOD by yeast biorecognition elements; the main reasons for selecting Saccharomyces cerevisiae as the biorecognition element is to select Baker’s Yeast as the rapid determination of BOD biorecognition materials are as follows:
1) Saccharomyces cerevisiae is a highly active aerobic microorganism with a strong ability to assimilate carbohydrates. It has been widely used in the comprehensive treatment of high-concentration organic industrial wastewater;
2) Saccharomyces cerevisiae itself has no toxic effect and will not cause secondary pollution to the environment;
3) Saccharomyces cerevisiae does not require high culture conditions and grows rapidly, so it is suitable for obtaining;
4) Baker’s Yeast can be stored dry for a long time, and can maintain the activity of the enzyme for a long time;
5) Saccharomyces cerevisiae cells have the characteristics of osmotic pressure resistance, and can be applied to the monitoring of marine pollution; the process of preparing biometric elements by using PVA-immobilized Saccharomyces cerevisiae: suspending Saccharomyces cerevisiae cells in deionized water at a concentration of 10-20g /100mL (w/v), then mix with the PVA solution that dissolves, obtain uniform mixed solution, the final concentration of PVA is 8-10% (w/v), this mixed solution is dripped in the saturated boric acid solution 500mL, Take it out after fully cross-linking for 10-12 hours, rinse it with deionized water for 3 times, and obtain the immobilized Baker’s Yeast particles as the biorecognition element, and put them in the refrigerator for later use; Rapid determination of: During the measurement, the immobilized microbial particles and the sample to be tested are mixed in the measurement chamber, stirred and aerated with a micro-aeration tube to saturate the dissolved oxygen, and the immobilized microbial particles are decomposing organic pollutants. Decompose the biodegradable organic pollutants in the water body, and consume the dissolved oxygen in the water body, so that the dissolved oxygen concentration is continuously reduced, causing the dissolved oxygen to gradually decrease to a new stable state; according to the dissolved oxygen difference between the two steady states Value, the BOD value of the measured water sample can be calculated through the standard curve.
The two steady states refer to: the first steady state is set when the water sample reaches the predetermined measurement temperature, and the second steady state is set as the change range of the current value reading for three consecutive times is less than 0.001 μA. The immobilized microbial particles are immobilized Saccharomyces cerevisiae particles. The beneficial effect of the present invention is that compared with the biometric components of the BOD rapid measuring instrument currently used, the Saccharomyces cerevisiae proposed by the present invention makes up for its many deficiencies:
(1) Baker’s Yeast has high metabolic activity and strong ability to decompose organic pollutants, which broadens the measurement range of various wastewater;
(2) According to the pollution degree of the water sample, the effective measurement range can be adjusted by changing the amount of immobilized microbial particles;
(3) The service life of immobilized microbial particles is longer, and the activation and preservation of microorganisms are simpler and more convenient;
(4) The immobilized Saccharomyces cerevisiae cells are resistant to osmotic pressure. Therefore, using Saccharomyces cerevisiae as a biorecognition element is suitable for rapid monitoring of organic pollution in marine water.