一株解磷菌的篩選及其培養(yǎng)條件優(yōu)化
發(fā)布時(shí)間:2018-07-12 17:13
本文選題:解磷菌 + 巨大芽孢桿菌 ; 參考:《浙江大學(xué)》2015年碩士論文
【摘要】:磷是植物生長(zhǎng)發(fā)育不可缺少的營(yíng)養(yǎng)元素之一,然而,我國(guó)農(nóng)田土壤缺磷面積占農(nóng)田總面積的2/3,施用磷肥是保證農(nóng)業(yè)生產(chǎn)的重要手段。磷素在土壤中極易固定,我國(guó)磷肥當(dāng)季利用率只有10%~20%,導(dǎo)致大量磷素以難溶態(tài)磷殘留在土壤中,形成巨大的磷庫(kù)。解磷微生物能夠促進(jìn)難溶性磷溶解,供植物吸收利用,因此,開發(fā)高效解磷微生物肥料是目前研究的熱點(diǎn)。本研究以篩選高效解磷菌株,并利用食品工業(yè)產(chǎn)生的有機(jī)廢水為營(yíng)養(yǎng)來(lái)源優(yōu)化其發(fā)酵培養(yǎng)條件為主要研究?jī)?nèi)容,以期為解磷菌的農(nóng)業(yè)應(yīng)用奠定基礎(chǔ),并實(shí)現(xiàn)廢棄物的資源化利用。取得的主要研究結(jié)果如下:(1)篩選出一株具有較強(qiáng)解磷能力的微生物菌株:巨大芽孢桿菌(Bacillus megaterium)。該菌株搖瓶培養(yǎng)7d,對(duì)Ca_3(PO_4)_2的降解率達(dá)16.21%,對(duì)磷礦粉降解率達(dá)6.49%。(2)篩選出以味精發(fā)酵廢液為主要營(yíng)養(yǎng)源的巨大芽孢桿菌基礎(chǔ)培養(yǎng)基配方;通過正交試驗(yàn)得優(yōu)化配方為:牛肉膏1.0g、蛋白胨1.0g、味精廢液稀釋80倍、CaCO_31.0g、MgSO4·7H_2O1.0g、H_3BO_30.02g、H_2O1000mL。(3)單因子搖瓶培養(yǎng)試驗(yàn)結(jié)果表明:培養(yǎng)條件參數(shù)為:初始pH 7.0~7.5,溫度30℃~35℃,培養(yǎng)時(shí)間約36h,接種量約5%,裝液量約10%,轉(zhuǎn)速180r/min。(4)搖瓶培養(yǎng)補(bǔ)料試驗(yàn)表明,采用優(yōu)化配方培養(yǎng)9h時(shí)再補(bǔ)加原始配方中50%的味精廢液,有利于提高巨大芽孢桿菌菌體數(shù)。(5)兩步控制搖瓶培養(yǎng)試驗(yàn)表明,在培養(yǎng)前中期添加Mn~(2+)或在培養(yǎng)中期添加Ca~(2+)可顯著提高巨大芽孢桿菌培養(yǎng)終點(diǎn)芽孢數(shù),但初期添加Ca~(2+)會(huì)抑制菌體的生長(zhǎng);適當(dāng)提高培養(yǎng)中后期的pH、溫度及轉(zhuǎn)速均能顯著提高芽孢數(shù)。
[Abstract]:Phosphorus is one of the essential nutrient elements in plant growth and development. However, phosphorus deficiency in farmland soil accounts for 2 / 3 of the total farmland area in China. Phosphorus fertilizer is an important means to ensure agricultural production. Phosphorus is easy to be fixed in the soil. The utilization rate of phosphorus fertilizer in China is only 10% 20%, which leads to a large amount of phosphorus remaining in the soil with insoluble phosphorus, forming a huge phosphorus pool. Phosphorus-soluble microorganisms can promote insoluble phosphorus dissolution for plant absorption and utilization. Therefore, the development of high efficiency phosphorus-soluble microbial fertilizer is a hot research topic at present. In order to lay a foundation for the agricultural application of phosphorus releasing bacteria, the main research content of this study was to screen high efficient phosphorus releasing bacteria strains, and to optimize the fermentation and culture conditions by using organic wastewater produced by food industry as the nutrient source, in order to lay a foundation for the agricultural application of phosphorus releasing bacteria. And realize the resource utilization of waste. The main results are as follows: (1) Bacillus megaterium)., a microorganism strain with strong phosphorus solubilizing ability, was screened out. After 7 days of culture in shaking flask, the degradation rate of CaStu3 (PO4) 2 was 16.21 and the degradation rate of phosphate rock powder was 6.49. (2) the basic medium formula of Bacillus megaterium with MSG fermentation waste as the main nutrient source was selected. The optimum formula was obtained by orthogonal test as follows: beef paste 1.0 g, peptone 1.0 g, MSG waste liquid 80 times diluted CaCO31.0 g MgSO4 7H 2O 1.0 g H3BO30.02gStaH2O1000mL. (3) single factor shaking flask culture test showed that the culture conditions were as follows: initial pH 7.0, temperature 30 鈩,
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