有机物料腐熟剂制备条件的优化.pdf

郑州大学
硕士学位论文
有机物料腐熟剂制备条件的优化
姓名:狄源宁
申请学位级别:硕士
专业:环境科学
指导教师:郭夏丽
201205
摘娶
摘要
我国是一个农业大国,秸秆资源丰寓,但是大部分的秸秆资源被直接在田间
焚烧或被丢弃乱堆,造成资源浪费和环境污染。为了解决这一问题,一种新型的
微生物肥料一有机物料腐熟剂应运而生。本研究针对有机物料腐熟剂生产上的主
要问题,经过初筛得到纤维素酶活性及半纤维素酶活性较高的枯草芽孢杆茵,并
通过摇瓶试验硏究提髙枯草芽孢杄菌芽孢量的最住培养基组合和最优培养条件。
主要结论如下
1.在枯草芽孢杆菌培养基成分的优化试验中,长效的碳、氮源一麸皮和玉
米粉比速效碳、氮源有更好的效果,细胞总数量以及芽孢数量都较高,产芽孢率
可达到70%左右:当NaCl与KH2PO4浓度比为5:1时,芽孢数均高于这两种单
一无机盐的芽孢数。同时,在培养基中添加适量的锰离子也有利于芽孢的产生。
2.在枯草芽孢杆茵培养条件的优化试验中,通过对培养温度、初始pH值、
溶氧水平几方面的研究发现:在30℃的培养温度时,芽孢数及细胞数量最高,
分别为6.2×105 cfu ml和86×10 cfu ml',其产芽孢率达到72.1%:在初始
pH中性条件下时,芽孢数量最大:;芽孢数在一定范围内随着装液量的增加而升
高,而后随着装液量的继续升高而减少,装液量为50mL/250mL时,芽孢数量最
大,溶氧水平达到最佳:通过对培养基组成及培养条件的优化,得出最佳的产孢
培养基为:麸皮5g,玉米粉10g, NACI5g,KH2PO41g,MnSO4H2O0.4g,水
100o。在30℃、初始pH7,0时,其细胞数及芽孢数可达到41×10 cfu ml
和3.4×10 cfu ml1,产芽孢率可到达82.9%。
3.在单一载体的微生物吸附试验中,吸附7d后麸皮能够增加菌体和芽孢数
而腐熟堆肥则能保持活体和芽孢数的稳定;将麩皮和堆肥按1:1混合,吸附菌
体60d后,其有效活菌数保持稳定,数量可达到2.62×10cig2,满足有机物料
腐熟剂产品的技术要求;由于堆肥来源丰富,在大规模的工业生产中将其作为载
体生产固体微生物菌剂,可以大大节省成本。
关键词:有机物料降解;枯草芽孢杄茵菌剂;产孢条件;载体吸附
bstract
Abstract
Development of Bacillus subtili formulation for organic material de radation
There are about 90 million tons of wheat straw produced annually in China
However most of wheat straw is bumt in the fields or discarded. This causes serious
waste of resources and environmental pollution. The microbes inoculant used to
acceleration of straw decomposition in the field is urgently needed. The aim of this
research was to produce a stable biological formulation with environmentally friend,
microorganism Bacillus subtilis with higher activity of celluase and hemicelluase by
strain screening, cultural conditions optimizing and strain adsorping. The result
could be used to provide a reliable basis for scaling up the fermentation process to an
industrial level. The main conclusions were as follow:
1, With bran as carbon source, the spore level of Bacillus subtilis increased
significantly, showing the highest spore yield among all carbon source tested. 5g.L
was selected as the optimum concentration of bran because the highest yield of spores
was obtained at this concentration. With com powder as nitrogen source, the highest
yield of both spores and vegetative cells was observed. Among the minerals tested,
the number of the spores produced in 5: 1 of Nacl and KH2 PO4 was greater than that
produced in sodium chloride or potassium phosphate alone. Meanwhile, addition of
Mn "(2. 4mmol L')significantly romoted sporulation, yielding 7 2x10'cfu ml. of
spores. So the optimized medium for spores of Bacillus subtilis was g L" bran
10g. L maize flour, Sg, I Nacl, 1g, L KH2P04 and 0. 4g, L Mnso4 H20
2, In culture conditions optimization experiments, the effect of incubation
temperature, initial PH and the level of dissolved oxygen on Bacillus subtilis
sporulation were determined. It was found that the numbers of both spores and