香蕉根际土壤无机磷细菌的筛

发布时间：2018-01-31 11:31

  本文关键词： 解磷微生物 鉴定 香蕉 促生效果　出处：《海南大学》2015年硕士论文　论文类型：学位论文

【摘要】：解磷微生物或溶磷微生物(Phosphate-solubilizing microorganism)是指土壤里能够将磷矿粉等植物难以吸收利用的磷酸盐转化为可吸收利用形态的微生物。现世界将近50%的农业土壤存在缺磷问题,这里的土壤缺磷是“遗传学缺磷”而非“土壤学缺磷”(康贻军等,2006；王庆仁,2004)。土壤缺乏磷素使植物的生长受到严重影响。直接施加化学磷肥,一定程度缓解土壤缺磷现象,但现在植物对磷肥等化学肥料是吸收利用率很低,不足25%,造成资源浪费,并且还会造成土壤板结、酸碱化等问题。因此,微生物磷肥的研究是现农业研究的热点项目。本文以磷矿粉为底物,从香蕉根际土壤分离、筛选和鉴定一批高效解磷细菌,并研究了代表菌株解磷能力,优化了培养条件和解磷菌剂对香蕉幼苗的促生效果。 1、筛选并鉴定了3株具有高效溶解磷矿粉能力的细菌。香蕉根际土壤经过透明圈法和钼锑抗比色法测定发酵液有效磷含量进行初筛、复筛,得到了对磷矿粉溶解效果较好的解磷微生物B3-5-6,M-3-01和T1-4-01菌株。通过菌体形态观察、生理生化实验和16S rDNA分子生物学鉴定,可以判定菌株B3-5-6为嗜气芽孢杆菌(Bacillus aerophilus),M-3-01为虫内生沙雷氏菌(Serratia nematodiphila),T1-4-01为艾博丽肠杆菌(Enterobacter asburiae)。其中M-3-01菌株溶解磷矿粉效果最好,解磷能力为37.85mg/L,将其作为本实验解磷微生物代表菌株作更深入的研究。 2、优化了M-3-01代表菌株的解磷发酵配方工艺。通过设计单因子试验和正交试验方法相结合。单因子实验筛选了最佳碳源为葡萄糖,氮源为草酸铵。再通过确定碳源、氮源、磷矿粉、无机盐4组主要影响因子,进行L9(34)正交试验,筛选最优培养基浓度配方,再通过使用单因子试验,筛选最优配方的起始pH、转速、接种量等条件。最终确定了代表菌株M-3-01的高效解磷发酵配方。最终优化结果为：葡萄糖15g/L,草酸铵1.5g/L,磷矿粉2.5g/L,无机盐1.92g/L,2%接菌量,pH为6,150r/min,37℃。并对其配方进行了验证试验,优化组有效磷含量达88.64mg/L,是CK有效磷含量的2.34倍。 3、将代表解磷菌株M-3-01制成菌剂,和化肥磷矿粉作对照,研究菌剂对香蕉幼苗的促生效果、盆栽实验研究发现,菌株M-3-01菌剂+磷矿粉处理对香蕉幼苗促生效果最佳：该处理下香蕉植株的平均株高、茎围、鲜重、干重分别是对照的1.26、1.16、1.38、1.47倍；且脂膜过氧化及质膜透性渗透调节物质含量及效果均显著高于其它几个处理。针对香蕉植株根际土壤的理化因子进行分析,接解磷菌剂的处理组的有效磷含量显著高于CK,有效K和全氮的含量明显比CK的低,pH变化相对稳定,接近于中性。
[Abstract]:Phosphate-solubilizing microorganism (Phosphate-solubilizing microorganism). It is a kind of microorganism that can transform phosphate which is difficult to be absorbed and utilized by plants such as phosphate rock powder into absorbable microorganism in soil. Nearly 50% of the world's agricultural soils are deficient in phosphorus. The soil phosphorus deficiency here is "genetic phosphorus deficiency" rather than "soil phosphorus deficiency" (Kang Yi-jun et al. 2006; Wang Qingren 2004.The plant growth was seriously affected by phosphorus deficiency in soil. Direct application of chemical phosphorus fertilizer to some extent alleviated the phenomenon of phosphorus deficiency in soil. But now plants to phosphorus fertilizer and other chemical fertilizer absorption efficiency is very low, less than 25 percent, resulting in waste of resources, and will also cause soil consolidation, acid and alkali problems. Microbial phosphate fertilizer is a hot research project in agriculture. In this paper, phosphate rock powder was used as substrate to isolate, screen and identify a number of high-efficient phosphate releasing bacteria from banana rhizosphere soil, and the phosphorus releasing ability of representative strains was studied. The effects of culture conditions and phosphorus-releasing bacteria on the growth of banana seedlings were optimized. 1. Three strains of bacteria with high ability to dissolve phosphate rock powder were screened and identified. The available phosphorus content of fermentation broth was determined by transparent circle method and molybdenum antimony colorimetric method in banana rhizosphere soil. Strains B3-5-6CM-3-01 and T1-4-01 were obtained, which had better dissolution effect on phosphate rock powder. The morphology of bacteria was observed. The strain B3-5-6 was identified as Bacillus aerophilus by physiological and biochemical experiments and 16s rDNA molecular biological identification. M-3-01 is Serratia nematodiphila. T1-4-01 was Enterobacter asburiaeae, in which M-3-01 was the most effective in dissolving phosphate rock powder. The phosphorus releasing ability was 37.85 mg / L, which was further studied as the representative strain of phosphorus releasing microorganism in this experiment. 2. The fermentation formula of the representative strain M-3-01 was optimized. The optimum carbon source was glucose by the combination of single factor test and orthogonal experiment. The nitrogen source was ammonium oxalate. By determining the main influencing factors of carbon source, nitrogen source, phosphate rock powder and inorganic salt, the orthogonal experiment was carried out to select the optimal medium concentration formula, and then the single factor test was used. The optimum conditions such as initial pH, rotation speed and inoculation amount were selected. The fermentation formula of the representative strain M-3-01 was determined. The final optimization result was: glucose 15g / L. Ammonium oxalate 1.5 g / L, phosphate rock powder 2.5 g / L, inorganic salt 1.92 g / L 2% inoculated at pH 6 ~ 150 r / min ~ 37 鈩，

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