A method of representing quantity changes of groups of bacteria in a cow dung high-temperature composting process

Abstract

A method of representing quantity changes of groups of bacteria in a cow dung high-temperature composting process is provided. The method includes: performing high-temperature composting by adopting fresh cow dung and plant straw as main raw materials; collecting samples in different composting time periods; preparing composting water extracts; measuring dissolved organic carbon (DOC) of each composting water extract; diluting each composting water extract until the DOC is smaller than 10 mg / L; collecting three-dimensional excitation-emission matrix (EEM) fluorescence spectrums of the diluted composting water extracts; subjecting data of the collected three-dimensional fluorescence spectrums to Rayleigh-Raman scattering removal in an Matlab7.0 software; determining relative contents P<IV, n> of components having an excitation / emission wavelength of (250-280 nm) / (350-380 nm); and mapping a P<IV, n> changing curve of the composting process. The curve can be used for representing the quantity changes of the groups of the bacteria in the cow dung high-temperature composting process. The method can rapidly and cheaply monitor succession of groups of bacteria in the cow dung high-temperature composting process, and is low in cost and safe in operation.

Description

technical field [0001] The invention relates to the field of resource utilization of solid waste, in particular to a method for characterizing the changes in the number of bacterial groups in the high-temperature composting process of cow dung. Background technique [0002] China is a large agricultural country, which produces about 60 million tons of solid organic waste of nutrient resources every year, including livestock and poultry manure and crop straw, etc. If they are not properly utilized and disposed of at will, they will cause serious damage to water bodies, the atmosphere, soil and human health. cause negative impact. The composting process is an efficient means of disposing of agricultural solid waste. The composting process refers to the process of mixing livestock and poultry manure and other auxiliary materials in a certain proportion, and using the combined action of microorganisms inherent in the composting materials to gradually degrade organic matter into...

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Problems solved by technology

However, since compost samples contain up to 30%-70% organic matter, which is much higher than that of general environmental samples, it brings considerable difficulty to DNA extraction

In addition, because the composting process is also a humification process of organic matter to a certain extent, the samples in the later stage of composting contain a large amount of humic acid, and humic acid has similar structural characteristics with DNA, which is not easy to remove during the purification process, and will Some influence on the PCR process

However, the use of DGGE technology to analyze the changes of bacterial species in compost samples, the extraction and purification of DNA and the amplification of PCR are key steps, which are difficult to avoid, so it will affect the diversity analysis of microorganisms to a certain extent

And the operation process is complicated and the cost is high

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