三株优势菌对多环芳烃的降解性能研究

多环芳烃具有毒性、生物蓄积性和半挥发性，并能在环境中持久存在。生物修复处理具有费用低、效果好、污染物残留量低、不产生二次污染、能够保持或改善植物生长的土壤结构等优点。实验分别在对单一菌株、两两混合菌株及三株菌混合等三种情形下，对蒽、菲、芘的降解作用进行了研究。研究结果表明：单一菌株对蒽、菲、芘有一定的降解能力，菌株混合时，对蒽、菲的降解率有所提高；三株菌种混合时，黄杆菌对放线菌、红球菌的生长过程有抑制作用；蒽、菲、芘的降解过程会不断交替进行着产酸和脱羧过程，使降解液pH值出现波动；同时在降解过程中，菌体能产生表面活性物质，这有利于蒽、菲、芘的生物降解转化。     

营养和环境条件对生物絮凝剂合成的影响

在考察了红平红球菌Rhodococcus erythropolis CCRC10900基本生长代谢特性的基础上，研究了营养条件对生物絮凝剂合成的影响。R.erythropolis CCRC10909合成的絮凝剂约80％以上分泌至胞外培养基中，仅20％左右的絮凝活性存在于菌体细胞上，蔗糖是该菌生长及絮凝剂合成的最佳碳源；玉米浆既能刺激菌体生长，又能显著提高絮凝剂的水平，生物絮凝剂的合成与培养基碳氮比密切相关，碳氮比在20－30之间时，絮凝活性达到最大，碳氮比低于10或高于100后，絮凝活性迅速下降，提出了促进絮凝剂合成的控制策略，发酵前期适当提高玉米浆的浓度，发酵后期按碳氮比为20－30，补加一定量的蔗糖和尿素，实验结果表明，采用这一策略，最终发酵液的絮凝活性和细胞生长量分别增长了8％和33．3％。     

纳米Al_2O_3固定化红平红球菌菌球的制备及其对苯酚的降解

以海藻酸铝为主要包埋材料、纳米Al_2O_3为添加剂,包埋固定红平红球菌,制得纳米Al_2O_3固定化红平红球菌菌球,并将其用于苯酚的降解。表征结果显示:菌球内部包含丰富的菌丝体;内部孔径以中孔居多。实验结果表明:菌球的最优制备方案为0.05 g纳米Al_2O_3加入3 m L海藻酸钠溶液中、海藻酸钠质量分数6%、微生物包埋量0.5 m L/m L(以海藻酸钠溶液计)、Al_2(SO_4)_3质量分数3%;在初始苯酚质量浓度为400 mg/L、反应时间为24h、菌球加入量为8 g/L、反应p H为8.0、反应温度为30℃的条件下,菌球首次使用时可使苯酚完全降解,使用5次后的苯酚降解率仍达93%以上,具有良好的循环使用性。     

Effects of nicotinamide and riboflavin on the biodesulfurization activity of dibenzothiophene by Rhodococcus erythropolis USTB-03

Rhodococcus erythropolis USTB-03 is a promising bacterial strain for the biodesulfurization of dibenzothiophene (DBT) via a sulfurspecific pathway in which DBT is converted to 2-hydroxybiphenyl (2HBP) as an end product. The effects of nicotinamide and riboflavin on the sulfur specific activity (SA) of DBT biodesulfurization by R. erythropolis USTB-03 were investigated. Both nicotinamide and riboflavin were found to enhance the expression of SA, which was not previously reported. When R. erythropolis USTB-03 was grown on a medium containing nicotinamide of 10. 0 mmol or riboflavin of 50. 0 μnol, SA was raised from 68. 0 or so to more than 130 mmol 2HBP/(kg dry cells. h). When R. erythropolis USTB-03 was grown in the presence of both nicotinamide of 5. 0 mmol and riboflavin of 25. 0 μmol, SA was further increased to 159. 0 mmol 2HBP/(kg dry cells. h). It is suggested that the biological synthesis of reduced form of flavin mononucleotide (FMNH2), an essential coenzyme for the activities of biodesulfurization enzyme Dsz C and A, might be enhanced by nicotinamide and riboflavin, which was responsible for the increased SA of R. erythropolis USTB-03.     

厌氧后猪场废水资源化制备微生物絮凝剂

通过检测碳源、氮源、磷酸盐和pH等对微生物絮凝剂絮凝率的影响,考察了红平红球菌利用厌氧处理后的猪场废水生产微生物絮凝剂的性能。通过正交实验研究各因素对絮凝率的交互影响以及影响程度的相对大小,从而确定了最佳培养基。结果表明,1.0 L厌氧处理后的猪场废水中加入蔗糖10.0 g、KH2PO42.0 g、K2HPO45.0 g、NaCl 1.0 g、Mg-SO40.2 g,在温度30℃、摇床速度120 r/min、pH=8的条件下发酵72 h后,发酵液的絮凝率可达到92.57%。表明厌氧处理后的猪场废水中加入适量的蔗糖和磷酸盐,完全可以作为一种有效的生产微生物絮凝剂的培养基。     

不同硫源对红串红球菌生长和脱硫比活性的效应

本文牛磺酸、硫酸镁和二苯噻吩（ＤＢＴ）分别作为唯一硫源以及ＤＢＴ不同供给量对红串红球菌生长和脱硫比活性的效应进行了研究，结果表明，红串红球菌肯 利用有机和无机硫化合物作为硫源的能力。与牛磺酸和到镁相比，ＤＢＴ是促进红串红球菌生长和提高其脱硫比活红串红球菌的最大脱硫比活性达７９．１ｍｍｏｌ２ＨＢＰ．ｋｇ＾－１．ｈ＾－１。影响红串红球菌脱硫比活性的因素主要是其生长的不同阶段、ＤＢＴ供给量和羟基二苯生产     

白腐菌和红平红球菌共固定化处理增塑剂废水

以赭曲霉死菌丝体为载体,吸附红平红球菌(Rhodococcus erythropo lisNG0402)和白腐菌(Phanerochaete chrysosporiumM E-446)的混合物,用聚乙烯醇作包埋剂进行共固定化。用制备好的共固定化细胞处理增塑剂废水,连续运行19d的结果表明,共固定化处理增塑剂废水的效果远好于单一菌的效果。在pH7.0、溶解氧质量浓度3.0m g/L、水力停留时间25h的条件下,废水中苯酚、COD和色度的去除率连续15d达到了90%以上,对苯酚的去除能力为2.16kg/(m3.d)。     

Isolation and preliminary characterization of a 3-chlorobenzoate degrading bacteria

A study was conducted to compare the diversity of 2-, 3-, and 4-chlorobenzoate degraders in two pristine soils and one contaminated sewage sludge. These samples contained strikingly different populations of mono-chlorobenzoate degraders. Although fewer cultures were isolated in the uncontaminated soils than contaminated one, the ability of microbial populations to mineralize chlorobenzoate was widespread. The 3- and 4-chlorobenzoate degraders were more diverse than the 2-chlorobenzoate degraders. One of the strains isolated from the sewage sludge was obtained. Based on its phenotype, chemotaxonomic properties and 16S rRNA gene, the organism S-7 was classified as Rhodococcus erythropolis. The strain can grow at temperature from 4 to 37℃. It can utilize several （halo）aromatic compounds. Moreover, strain S-7 can grow and use 3-chlorobenzoate as sole carbon source in a temperatures range of 10-30℃ with stoichiometric release of chloride ions. The psychrotolerant ability was significant for bioremediation in low temperature regions. Catechol and chlorocatechol 1,2-dioxygenase activities were present in cell free extracts of the strain, but no （chloro）catechol 2,3- dioxygenase activities was detected. Spectral conversion assays with extracts from R. erythropolis S-7 showed accumulation of a compound with a similar UV spectrum as chloro-cis,cis-muconate from 3-chlorobenzoate. On the basis of these results, we proposed that S-7 degraded 3-chlorobenzoate through the modified ortho-cleave pathway.     

鸡粪除臭菌的筛选、培养条件优化及其应用

为了筛选出具有高效除臭能力的菌株,采用驯化富集、平板划线的方法从鸡粪中筛选除臭微生物,采用初筛、复筛相结合的方法检测所筛选微生物的除臭效果。初筛采用嗅阈值法,复筛以氨气和硫化氢的去除率为检测指标,最终获得除臭效果最好的菌株CCJZ022。经过形态学观察、生理生化鉴定和16S rRNA基因序列分析,确定菌株CCJZ022为红平红球菌(Rhodococcus erythropolis)。对其初始pH值、培养温度及接种量进行优化,发现该菌株在初始pH值为7.0、培养温度为30℃、接种量为12%时除臭效果最好,对氨气和硫化氢的去除率分别可达66.73%和54.51%。利用该菌株进行鸡粪除臭的小试也取得了很好的效果,表明该菌株可以应用于鸡粪除臭。     

红串红球菌TJQ对不同形式硫的脱除研究

红串红球菌TJQ是本实验室筛选的一株专一性脱硫菌，高效液相色谱法（HPLC）分析表明．该菌能选择性地脱除二苯并噻吩（DBT）中的硫，最终代谢产物是2-羟基联苯（2-HBP）。实验结果表明，该菌既可以利用有机硫源又可以利用廉价的无机硫源作为生长硫源，以硫酸钠作为硫源培养的菌株可专一性脱除苯并噻吩（BT）和DBT及其甲基衍生物4，6-二甲基二苯并噻吩（4，6-DMDBT）中的硫。除此之外，它还可以脱除苯硫醚（PS）和硫醇类含硫化合物中的硫。在正十六烷模拟体系中菌株对噻吩（TH）、4，6-DMDBT、DBT等类型的硫的降解效率很高，对BT和PS类硫的降解效率也较好。它可以使实际柴油中总硫含量由554mg／L降到267mg／L，降解率达到51．8%。