固定化生防菌的生物质炭基载体构建与评价

Improvement and Evaluation of Biochar Carrier for Ginseng Biocontrol Bacteria

解淀粉芽胞杆菌(SZ-60)在人参病害防控及参后地土壤微生物修复方面存在巨大潜力,但直接施用存在活菌数偏少、防效不稳定等问题。拟采用微生物固定化技术,以生物质炭为基础载体,筛选并优化适用于解淀粉芽胞杆菌定殖的炭基载体改性条件,分析载体改性前后性质变化与定殖能力变化的关系,为提升SZ-60防效奠定基础,对该类菌种的开发利用进行研究。结果显示,生物质炭固定化微生物最适改性方法为超声波耦合乙酸改性法。最适改性工艺为:乙酸浓度0.2 mol/L,浸渍时间30 min,料液比1:3,超声时间10 min。改性炭基载体上生防菌定殖数达到原炭的2.88倍。改性前后炭基载体共有16项指标发生了显著变化,以养分元素含量变化最为显著,变幅为33.71%~91.87%。其中铁、锌含量、固定碳占比、挥发分占比是影响定殖效果的关键指标。结果表明,超声波耦合乙酸改性可显著影响生物质炭基载体的养分性质,从而提升解淀粉芽胞杆菌的定殖活菌数。该载体的构建为进一步开展参后地土壤微生物修复实验以及相关生物质炭基微生物菌剂开发奠定了良好的基础。

Bacillus amyloliquefaciens SZ-60 has great potential in the prevention and control of ginseng diseases and the microbial remediation of soil after ginseng planting,but there are problems such as less viable bacteria and unstable control effect when applied directly.Taken biocarbon as the basic carrier,the modification conditions of carbon-based carriers suitable for the colonization of B.amyloliquefaciens was screened and optimized,and the relationship between the property changes of carriers before and after modification and the changes of colonization capacity was analyze,which will lay a foundation for improving the control effect of SZ-60,and development and utilization of this kind of bacteria.The results showed that the most suitable modification method for immobilized microorganisms on biochar was ultrasonic coupling acetic acid modification.The optimum modification process is as follows,acetic acid concentration 0.2 mol/L,immersion time 30 min,material liquid ratio 1:3,and ultrasonic time 10 min.The number of biocontrol bacteria colonization on the modified carbon-based carrier was 2.88 times of that on the original carbon.A total of 16 indicators of carbon-based carrier changed significantly before and after modification,with the most significant change in nutrient element content,ranging from 33.71%to 91.87%.The content of iron and zinc,the proportion of fixed carbon and the proportion of volatile matter are the key indicators affecting the colonization effect.The results showed that ultrasonic coupling acetic acid modification could significantly affect the nutrient properties of biochar carrier,thereby increasing the number of viable bacteria colonized by B.amyloliquefaciens.The construction of the carrier has laid a good foundation for further soil microbial remediation experiments and the development of microbial agents based on relevant biochar.