铜绿假单胞菌菌剂载体的筛选

Screening of carrier for Pseudomonas aeruginosa bacterial agent

为将铜绿假单胞菌应用于重金属污染环境的生物修复，以硅藻土（1～3mm）、硅藻土（3～6mm）、活性炭和轻石为材料，通过测定不同材料的吸水率、菌体吸附与释放作用及制备菌剂的活菌数，筛选出适宜的菌剂载体．结果表明，在设定的载体浓度下（0～20g·L^-1），不同载体的菌体去除率随浓度提高而增大，Q值在4．90％～49．60％之间；载体负载量随浓度提高而减小，￡值在923．33～82．83mg·g^-1之间；硅藻土、活性炭的Q值在30min达到最大．硅藻土（1～3mm）、硅藻土（3～6mm）、活性炭和轻石的吸水率依次为60．3％、43．3％、23．4％和33．1％；以上4种载体制备的菌剂（菌剂A、B、C和D）的活菌释放率依次为27．4％、28．8％、19．7％和37．1％．室温保存30d后，菌剂A活菌数为6．25×10^8CFU·g^-1，减少了78．4％，菌剂B活菌数为1．12×10^10CFU·g^-1，是初始值的5．38倍，菌剂C的活菌数为2．95×10^CFU·g^-1，减少了73．9％，菌剂D的活菌数为3．61×10^9CFU·g^-1．增殖了127．0％．可见，载体浓度及吸附时间显著影响其对菌体的吸附作用，3～6mm硅藻土的负载量适中，菌体存活率高，活菌释放率高，可作为铜绿假单胞菌的菌剂载体．

To optimize the application of Pseudomouas aerugiuosa in bioremediation of heavy metal-polluted environment, carriersfor bacterial agent, including diatomite at two particle sizes （1-3 mm and 3-6 ram） , activated carbon and pumice were screened byP. aeruginosa to evaluate their performances in bacteria adsorptshowed that bacteria removal rates increased from 4.90% to 49on and release, water absorption, and bacteria survival rate. Results60% along with increasing concentrations of carrier from 0 g· L^-1 to20 g · L^-1. Conversely, loading capacity of carriers decreased from 923.33 to 82.83 mg ·g^-1 when carrier concentrations increased.Diatomite and activated carbon reached the maximum bacteria removal rates 30 minutes after being exposed to bacterial agent. Bibu-lous rates for diatomite （ 1-3 ram）, diatomite （3-6 ram）, activated carbon and pumice were 60.3%, 43.3%, 23.4% and 33.1%,respectively, with living bacteria release rates reaching 27.4%, 28.8%, 19.7% and 37.1% accordingly. After being preserved atroom temperature for 30 days, bacteria populations of diatomite （ 1-3 ram） and activated carbon decreased by 78.4% and 73.9%, -1 -1reaching at 6.25×10^8 CFU·g^-1 and 2.95×10^8 CFU ·g^-1 , while those of diatomite （3-6 mm） and pumice were 5.38 and 1.27 timeshigher than the initial populations, resulting in 1.12×10^10 CFU·g^-1 and 3.61×10^9, respectively. To summarize, carrier concentra-tion and adsorption time significantly affected adsorption efficacy of bacteria carrier. Overally speaking, diatomite at particle size of 3-6 mm has moderate loading capacity, high bacteria survival rate and living bacteria release rate, and was considered an excellentmaterial for carrier of P. aerugiuosa agent.