好氧堆肥高温期的嗜热真菌和嗜热放线菌群落结构

Succession of thermophilic fungi and actinomycetes communities during the thermophilic period of aerobic composting

使用传统的培养方法和PCR-DGGE技术对好氧堆肥高温期的嗜热真菌和嗜热放线菌群落结构进行了研究.分别采用园林垃圾和餐厨垃圾作为堆肥原料,进行了20d好氧堆肥,高温期(≥50℃)持续了10d和8d.分别对2堆体高温期样品进行稀释平板混菌培养,真菌总数和放线菌总数均分别呈"降低-升高"和"升高-降低-升高"的趋势.同时提取微生物总DNA,分别使用真菌引物对(GC-NS7 /NS8)和放线菌引物对(F243 /GC-R513)从总DNA中成功扩增得到目标产物,对目标产物进行DGGE分离.传统培养法和DGGE图谱结果显示,不同堆体高温期的嗜热真菌和嗜热放线菌均表现出相似的变化规律,嗜热真菌优势菌比嗜热放线菌明显,但菌群总数比嗜热放线菌少.聚类分析结果表明,堆肥高温期嗜热真菌和嗜热放线菌分别以升温时56℃和58℃为界,分成2个明显的变化阶段,每阶段内部聚类关系较近,阶段间关系较远.温度对高温期真菌和放线菌具有明显的筛选作用.

The succession profile of thermophilic fungi and actinomycetes communities during the thermophilic cmnposting period was studied bv a traditional incubation method and by polymerase chain reaction-denaturing gradient gel electrophoresis （ PCR-DGGE ）. Two aerobic composts were processed with garden waste and kitchen trash for 20 days. The thermophilic period of the garden and kitchen waste composts （ ≥50℃ ） lasted 10 d and 8 d respectively. The mixed fungi and actinomycetes in samples of the two windrows during tbe thermophilic period were cuhured on dilution plates, and the total population change of fungi and actinomycetes showed a wave-like curve, i. e ＂down-up＂ and ＂up-down-up＂, respectively. Total microbial DNA was extracted from the samples, and the target products were successfully amplified using fungal primer pairs （ GC-NS7/NS8 ） and actinomycete primer pairs （F243/GC-R513） and then separated by DGGE. The traditional incubation results and DGGE profiles show that the populations of the thermophilic fungi and actinomycetes during the thermophilie period in the two windrows have similar characteristics. Certain species of themophilic fungi were preponderant, while the total population of the themophilic fungi was less than that of the themophilic actinomycetes. Cluster analysis indicated that the thermophilie composting period can be divided into two phases according to the themophilic fungi and actinomycetes populations. The themophilic fungi and actinomycetes were predominant at temperatures higher than 56 ℃ and 58 ℃ , respectively. The clustering relationships are close within each phase, while the relationships between the phases are distant. Temperature plays a great role in training thermophilic fungi and actinomycetes during the thermophilic composting period.